U.S. patent application number 10/091709 was filed with the patent office on 2002-07-18 for methods and compositions for treating microtubule-mediated viral infections and lesions.
Invention is credited to Gallaher, Robert G..
Application Number | 20020094991 10/091709 |
Document ID | / |
Family ID | 26818520 |
Filed Date | 2002-07-18 |
United States Patent
Application |
20020094991 |
Kind Code |
A1 |
Gallaher, Robert G. |
July 18, 2002 |
Methods and compositions for treating microtubule-mediated viral
infections and lesions
Abstract
The present invention provides methods and compositions for
preventing or treating virus infections in mammals that utilize
microtubule dynamics within mammalian cells. The compositions are
applied to mammals via parenteral, oral, anal, aural, ocular,
nasal, and topical routes of administration until clinical signs
are resolved.
Inventors: |
Gallaher, Robert G.;
(Seattle, WA) |
Correspondence
Address: |
Mark D. Byrne
BLACK LOWE & GRAHAM PLLC
816 Second Avenue
Seattle
WA
98104
US
|
Family ID: |
26818520 |
Appl. No.: |
10/091709 |
Filed: |
March 5, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10091709 |
Mar 5, 2002 |
|
|
|
09506415 |
Feb 17, 2000 |
|
|
|
60120582 |
Feb 18, 1999 |
|
|
|
Current U.S.
Class: |
514/283 ; 514/27;
514/369; 514/449; 514/613 |
Current CPC
Class: |
A61K 31/337 20130101;
A61K 45/06 20130101; A61K 2300/00 20130101; A61K 36/63 20130101;
A61K 36/63 20130101 |
Class at
Publication: |
514/283 ; 514/27;
514/369; 514/449; 514/613 |
International
Class: |
A61K 031/4745; A61K
031/337; A61K 031/7048; A61K 031/427; A61K 031/16 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A method to treat viral infection in mammals, the method
comprising: receiving an effective amount of at least one of a
plurality of compositions targeting a plurality of microtubule
processes in mammalian cells, the effective amount being delivered
by parental routes of administration to reduce non-dermal viral
infections for viruses utilizing the plurality of microtubule
processes in mammalian cells.
2. The method of claim 1, wherein the plurality of compositions
targeting the microtubule process in mammalian cells includes
taxanes, taxoids, discodermolide, epothilones A, epothilone B,
eleutherobin, taccalonolide, colchicine, colcemid, demecolcine,
vincrisitine, vinepidine, vindesine, vinblastine, vinorelbine,
desformyl vincrisitine, desacetyl desformyl vincristine,
vinflunine, phomopsin A, ustiloxins, cryptophycins, halichondrins,
estramustine, rhizoxin, and nocodazole.
3. The method of claim 2, wherein the plurality of compositions
further includes solubilizers, parenteral solutions, and
analgesics.
4. The method of claim 3, wherein the parenteral solutions are
water-based and includes saline, lactose, sucrose, sorbitol,
mannitol, starches, gum acacia, calcium phosphate, alginates,
tragacanth, gelatin, calcium silicate, cellulose, methyl cellulose,
microcrystalline cellulose, and polyvinylpyrrodlidone.
5. The method of claim 1, wherein the parental route of
administration includes intervascular injections, intermuscular
injections, interdermal injections, interspinal injections, and
intercerebral injections.
6. The method of claim 1, wherein the viruses utilizing the
microtubule process in mammalian cells includes Herpesvirus-1
(HSV-1), Herpesvirus-2 (HSV-2), Cytomegalovirus (CMV),
Varacella-Zoster Virus (VZV), Epstein Barr virus (EBV), Herpes
Simplex 6 (HSV-6), Herpes Simplex 7 (HSV-7), Herpes Simplex 8
(HSV-8), human Papilloma Virus (HPV), Vaccinia Virus (VV),
Adenovirus, Parvovirus, Human Infectivity Virus (HIV), and rabies
virus.
7. The method of claim 1, wherein the parental route of
administration includes filling a syringe with an effective amount
of at least one of the plurality of compositions to reduce viral
infections into the syringe, injecting the effective amount into a
mammal, assessing whether virus reductions in virus infections are
manifested as improvements in clinical signs presented by the
mammal, and re-injecting the effective amount until reductions in
virus infections are manifested as improvements in clinical signs
presented by the mammal.
8. A method to treat viral infection in mammals, the method
comprising: receiving an effective amount of at least one of a
plurality of compositions targeting a plurality of microtubule
processes in mammalian cells, the effective amount being delivered
by oral, anal, aural, ocular and nasal routes of administration to
reduce viral infections for viruses utilizing the plurality of
microtubule processes in mammalian cells.
9. The method of claim 8, wherein the plurality of compositions
targeting the microtubule process in mammalian cells includes
taxanes, taxoids, discodermolide, epothilones A, epothilone B,
eleutherobin, taccalonolide, colchicine, colcemid, demecolcine,
vincrisitine, vinepidine, vindesine, vinblastine, vinorelbine,
desformyl vincrisitine, desacetyl desformyl vincristine,
vinflunine, phomopsin A, ustiloxins, cryptophycins, halichondrins,
estramustine, rhizoxin, and nocodazole.
10. The method of claim 8, wherein the plurality of compositions
further includes solubilizers, solutions, and analgesics.
11. The method of claim 10, wherein the solutions are water-based
and includes saline, lactose, sucrose, sorbitol, mannitol,
starches, gum acacia, calcium phosphate, alginates, tragacanth,
gelatin, calcium silicate, cellulose, methyl cellulose,
microcrystalline cellulose, polyvinylpyrrodlidoneincludes and
syrup.
12. The method of claim 8, wherein the viruses utilizing the
microtubule process in mammalian cells includes Herpesvirus-1
(HSV-1), Herpesvirus-2 (HSV-2), Cytomegalovirus (CMV),
Varacella-Zoster Virus (VZV), Epstein Barr virus (EBV), Herpes
Simplex 6 (HSV-6), Herpes Simplex 7 (HSV-7), Herpes Simplex 8
(HSV-8), human Papilloma Virus (HPV), Vaccinia Virus (VV),
Adenovirus, Parvovirus, Human Infectivity Virus (HIV), and rabies
virus.
13. The method of claim 8, wherein the oral, anal, aural, ocular,
and nasal routes of administration includes filling a container
with an effective amount of at least one of the plurality of
compositions for reducing viral infections, transferring the
effective amount from the container into a mouth, anus, ear, eye or
nose of a mammal, assessing whether virus reductions in virus
infections are manifested as improvements in clinical signs
presented by the mammal, and re-transferring the effective amount
into the mouth, anus, ear, eye or nose of the mammal until
reductions in virus infections are manifested as improvements in
clinical signs presented by the mammal.
14. A method to treat viral infection in mammals, the method
comprising: receiving an effective amount of at least one of a
plurality of compositions targeting a microtubule process in
mammalian cells, the effective amount being delivered by a topical
route of administration to reduce viral infections in dermal
lesions and inflamed areas for viruses utilizing the microtubule
processes in mammalian cells.
15. The method of claim 14, wherein the plurality of compositions
targeting the microtubule process in mammalian cells includes
taxanes, taxoids, discodermolide, epothilones A, epothilone B,
eleutherobin, taccalonolide, colchicine, colcemid, demecolcine,
vincrisitine, vinepidine, vindesine, vinblastine, vinorelbine,
desformyl vincrisitine, desacetyl desformyl vincristine,
vinflunine, phomopsin A, ustiloxins, cryptophycins, halichondrins,
estramustine, rhizoxin, and nocodazole.
16. The method of claim 14, wherein the plurality of compositions
further includes solubilizers, lubricants, emulsifiers, waxes,
solutions, preservatives, humectants, and analgesics.
17. The method of claim 16, wherein the solutions includes
parenteral are water-based and includes saline, lactose, sucrose,
sorbitol, mannitol, starches, gum acacia, calcium phosphate,
alginates, tragacanth, gelatin, calcium silicate, cellulose, methyl
cellulose, microcrystalline cellulose, polyvinylpyrrodlidonenormal,
and syrup.
18. The method of claim 16, wherein the solubilizers includes
dimethy sulfoxide (DMSO), alcohol, petrolatum, and corn oil.
19. The method of claim 14, wherein the viruses utilizing the
microtubule process in mammalian cells includes Herpesvirus-1
(HSV-1), Herpesvirus-2 (HSV-2), Cytomegalovirus (CMV),
Varacella-Zoster Virus (VZV), Epstein Barr virus (EBV), Herpes
Simplex 6 (HSV-6), Herpes Simplex 7 (HSV-7), Herpes Simplex 8
(HSV-8), human Papilloma Virus (HPV), Vaccinia Virus (VV),
Adenovirus, Parvovirus, Human Infectivity Virus (HIV), and rabies
virus.
20. The method of 14, whereby the topical route of administration
comprises contacting the dermal lesions and inflamed areas with at
least one of the plurality of compositions, rubbing the composition
into the dermal lesions and inflamed areas, and recontacting and
re-rubbing the dermal lesions and inflamed areas until the dermal
lesions and inflamed areas are resolved.
Description
PRIORITY CLAIM
[0001] This application is a continuation of patent application
Ser. No. 09/506,415-filed Feb. 17, 2000, and claims benefit under
35 U.S.C. .sctn.119(e) of prior Provisional Patent Application
Serial Number 60/120,582-filed Feb. 18, 1999.
FIELD OF THE INVENTION
[0002] This invention relates generally to treatment methods and
compositions comprising naturally occurring or synthetic compounds
that interfere with the normal structure and function of tubulin
and the normal formation of microtubule structures within a host
cell. The treatment methods are for preventing or treating virus
infections in a mammal, and the dermal or mucosal lesions or tumors
associated with certain viral infections in a mammal, that are
dependent upon the microtubule-mediated cytoplasmic transport of a
viral genome within the host cell, or otherwise exploits
microtubule dynamics within the host cell.
BACKGROUND OF THE INVENTION
[0003] Microtubules are one of the primary elements of the
cytoskeletal structure of virtually all eukaryotic cells.
Microtubules are hollow polarized cylinders of approximately 25 nm
constructed of protein heterodimers of .alpha.-tubulin and
.beta.-tubulin and are typically anchored to a
microtubule-organizing center (MTOC) located near the cell nucleus.
They have a dynamic fast-growing "plus-end" and a slower growing
"minus-end". The tubulin sub-units are moved toward the minus-end
of the microtubule when additional tubulin sub-units polymerize at
the plus-end, thus creating a "treadmilling" effect.
[0004] Microtubule associated proteins (MAPs) are involved in the
movement of materials across the cytoplasm. Dynein is a minus-end
directed MAP, and kinesin is a plus-end directed MAP. Dynein is
associated with the movement of materials across the cytosol from
the cell membrane toward the nuclear pore complex. One domain of
the dynein MAP attaches to the cargo and another domain attaches to
a tubulin sub-unit. As the tubulin sub-unit moves toward the
minus-end of the microtubule, it carries the cargo along with it.
Kinesin is associated with the movement of materials across the
cytosol from the nucleus toward the cell membrane.
[0005] Viral genomes are one example of materials that are
transported across the cytoplasm of a host cell by normally
functioning microtubule dynamics. For example, recent studies
investigating the mechanisms of viral transport in the cytoplasm
demonstrate that herpesvirus replication is dependent on the normal
functioning of microtubule dynamics within the host cell. An
incoming HSV capsid binds to the microtubule at the plus end as
described herein and is transported toward the minus-end where it
is released and enters the cell nucleus to begin the replication
process.
[0006] These observations suggest a novel approach to the
development of effective antiviral therapies comprising
pharmacological agents that interfere with the normal structure or
function of microtubules within mammalian cells. To the best of the
applicant's knowledge, such antiviral therapies have not heretofore
been identified or described.
[0007] Researchers have observed that a number of viruses are
dependent upon microtubule-mediated cytosolic transport for
replication. Examples of these may include, but not limited to,
Herpes Simplex 1 (HSV-1), Herpes Simplex 2 (HSV-2), Cytomegalovirus
(CMV), Varicella-Zoster virus (VCV), Epstein Barr virus (EBV),
Herpes Simplex 6 (HSV-6), Herpes Simplex 7 (HSV-7), Herpes Simplex
8 (HSV-8), Papilloma virus (PPV), Vaccinia virus (VV), Adenovirus,
Parvovirus, Human Immunodeficiency virus (HIV), and rabies
virus.
[0008] Examples of compounds that have been identified as
anti-microtubule agents include, but are not limited to, taxanes
and taxoids, discodermolide, epothilones A and B, eleutherobin,
taccalonolide, colchicine, colcemid, demecolcine, the vinca
alkaloids including vincrisitine, vinepidine, vindesine,
vinblastine, vinorelbine, desformyl vincrisitine, desacetyl
desformyl vincristine, and vinflunine, phomopsin A, ustiloxins,
cryptophycins, halichondrins, estramustine, rhizoxin, nocodazole,
and any analogues or derivatives of any of the above.
[0009] Taxanes (e.g., paclitaxel, docetaxel), discodermolide,
epithilones A and B, eleutherobin, and taccalonolide, are examples
of a novel class of anti-microtubule agents that share the ability
to stabilize microtubules by inducing tubulin polymerization and
inhibiting microtubule disassembly.
[0010] Paclitaxel (also known under the trademark Taxol.RTM.) is
perhaps the most familiar of the taxanes. It was first isolated in
1971 from the bark of Taxus brevifolia, commonly known as the
Pacific Yew, and was approved in 1992 by the US Food and Drug
Administration for treatment of metastatic ovarian cancer and later
for breast cancer. Its mechanism of action is believed to involve
promoting formation and hyperstabilization of microtubules, thereby
preventing the disassembly of microtubules necessary for completion
of cell division. It also has been reported that paclitaxel induces
expression of cytokines, affects the activity of kinases and blocks
processes essential for metastasis, in as yet uncharacterized
mechanisms of action.
[0011] Paclitaxel has attracted unusually strong scientific
attention, not only because of its unique antiproliferative
mechanism of action, but also because it is active against nearly
all cancers against which it has been tested, and because it has
been discovered to be an analog of numerous, closely-related
compounds occurring naturally. Taxanes are now recognized as an
important new class of anticancer compounds.
[0012] Eleutherobin was originally discovered in rare soft corrals
belonging to the family eleutherobia collected from a specific
region of the Indian Ocean near Australia. It has since been
synthesized by scientists at The Scripps Research Institute.
Eleutherobin has a mechanism of action similar to paclitaxel, i.e.,
the stabilization of microtubules and the inhibition of microtubule
disassembly.
[0013] Epithilones were originally isolated from a species of soil
bacteria collected from the banks of the Zambezi River in the
Republic of South Africa, and researchers at The Scripps Research
Institute have synthesized derivatives of these compounds.
Epothilones are of particular interest because they are more
soluble in water than paclitaxel, have higher activity, and are
more easily available (i.e., from a cellulose degrading bacterium).
They have been shown to displace paclitaxel from its binding site
in .beta.-tubulin, and have demonstrated a mechanism of action
similar to that of paclitaxel.
[0014] Discodermolide was originally isolated from the sponge
Discodermia dissoluta and has now been totally synthesized.
Discodermolide binds to tubulin dimers in microtubules and induces
the polymerization of tubulin similar to paclitaxel, and is perhaps
even more potent as anti-microtubule agent.
[0015] Colchicine, colcemid, demecolcine, the vinca alkaloids
including vincrisitine, vinepidine, vindesine, vinblastine,
vinorelbine, desformyl vincrisitine, desacetyl desformyl
vincristine, and vinflunine, phomopsin A, ustiloxins,
cryptophycins, halichondrins, estramustine, rhizoxin, and
nocodazole are examples of a novel class of anti-microtubule agents
that share the ability to interfere with normal microtubule
dynamics by inhibiting the polymerization of tubulin within a host
cell, thus preventing the formation of microtubules.
[0016] Colchicine is a water-soluble alkaloid found in the autumn
crocus. The vinca alkaloids, vinblastine and vincristine, are
derived from the Madagascar periwinkle, and vindesine and
vinorelbine are semisynthetic derivatives of vinblastine. These
alkaloids also apparently interfere with a cell's ability to
synthesize DNA and RNA. The ustiloxins and phomopsins are a family
of tubulin-binding cyclic peptides, which have shown potent in
vitro anti-tumor activity, particularly against human breast and
lung cancer cell lines. Rhizoxin is produced by the fungus Rhizopus
chinensis, and has also demonstrated the ability to inhibit the
polymerization of tubulin into microtubules.
[0017] Thus, there is an unmet need to have an anti-viral treatment
repertoire using a plurality of compositions against a plurality of
viruses that target microtubule related processes.
SUMMARY OF THE INVENTION
[0018] The invention provides the treatment repertoire using
effective amounts of at least one composition of the plurality of
compositions that target microtubule related processes that are
introduced to mammals via parenteral, oral, nasal, anal, aural,
ocular, and topical routes of administration. The parenteral routes
of administration includes intervascular injections, intermuscular
injections, interdermal injections, subdermal injections,
interspinal injections, and intercerebral injections. The
intervascular injections further include intravenous and
interarterial injections.
[0019] The invention provides formulations comprising an effective
amount of one or more pharmacological agents known to interfere
with the normal structure or function of microtubules. The
invention describes an application of these formulations to
mammalian cells, either topically or systemically, for the purpose
of preventing or treating viral infections and the dermal or
mucosal lesions or tumors associated with viral infections.
[0020] The present invention provides compositions and methods for
treating diseased, biological tissue, such as the epidermis, in
mammals. The plurality of compositions of the present invention can
be used to treat epidermal lesions, such as those resulting from
viral infections including, but not limited to: HSV-1, HSV-2,
HSV-6, HSV-7, HSV-8, VZV, CMV, EBV, and PPV. The plurality of
compositions of the present invention can also be used to treat
epidermal lesions, ulcerations, abrasions, inflammation and other
conditions resulting from microbial infections. In particular,
compositions of the present invention are especially adapted to
treat lesions caused by herpes viruses.
[0021] The effective amounts of at least one of the compositions of
a plurality of compositions applied to a mammal is determined by
assessing whether virus reductions in virus infections are
manifested as improvements in clinical signs presented by the
mammal, and re-applying the effective amount until reduction in
virus infections are manifested as improvements in clinical signs
presented by the mammal. How compositions are applied depend upon
the intended route of administration used in introducing the
effective amounts of compositions that target microtubule related
processes. The effective amounts depends upon composition
stabilities, concentrations, and solubilities, and whether single
or more than one composition is administered via parenteral, oral,
anal, aural, nasal, ocular, and topical routes of
administration.
[0022] In one embodiment, the present invention provides
compositions useful for treating diseased, biological tissue, such
as the epidermis, in mammals. The compositions of the present
invention are effective in treating viral infections and
inflammation and lesions associated with viral infections. The
compositions of the present invention include at least one
anti-microtubule agent. The anti-microtubule agent can be a
naturally occurring compound, a semi-synthetic compound, or can be
an entirely synthetic compound that is chemically synthesized by
any means known to those skilled in the art.
[0023] Examples of compounds that have been identified as
anti-microtubule agents include, but are not limited to, taxanes,
taxoids, discodermolide, epothilones A and B, eleutherobin,
taccalonolide, colchicine, colcemid, demecolcine, the vinca
alkaloids including vincrisitine, vinepidine, vindesine,
vinblastine, vinorelbine, desformyl vincrisitine, desacetyl
desformyl vincristine, and vinflunine, phomopsin A, ustiloxins,
cryptophycins, halichondrins, estramustine, rhizoxin, and
nocodazole. It is appreciated that the examples of compounds
include any analogues or derivatives of the foregoing
anti-microtubule agents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The preferred and alternative embodiments of the present
invention are described in detail below with reference to the
following drawings.
[0025] The foregoing aspects of many of the attendant advantages of
this invention will become more readily appreciated as the same
becomes better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0026] FIG. 1A is a Drug Screening Report for TBT which lists the
analytical results for bioactive effectiveness of TBT in terms of
CPE, EC.sub.50, CC.sub.50, IC.sub.50, SI=CCSO/EC.sub.50; Cytopathic
Effect Inhibition and Plaque Reduction Assays For HSV-1, HSV-2,
CMV, MCMV, and VSV, in HFF cell cultures are detailed;
[0027] FIG. 1B is a Drug Screening Report for TBT which lists the
analytical results for bioactive effectiveness of TBT in terms of
CPE, EC.sub.50, CC.sub.50, IC.sub.50, SI=CC.sub.50/EC.sub.50;
Cytopathic Effect Inhibition and Plaque Reduction Assays For EBV in
DAUDI cell cultures are detailed; Toxicity Assays in HFF and DAUDI
cell cultures are detailed;
[0028] FIG. 2 is a descriptive listing of the HSV ELISA Method
procedural steps used in measuring the anti-viral effectiveness of
TBT to various HSV-1 and HSV-2 strains;
[0029] FIG. 3 represents the analytical IC.sub.50 results for HSV-1
viral antigens, specifically, for HSV-1 control (ATCC #VR-733,
Strain F), which demonstrated a TBT-IC.sub.50=3 .mu.g/ml;
[0030] FIG. 4 represents the analytical IC.sub.50 results for HSV-1
viral antigens, specifically, for HSV-1, clinical specimen #1
(TBT-IC.sub.50=3 .mu.g/ml);
[0031] FIG. 5 represents the analytical IC.sub.50 results for HSV-1
viral antigens, specifically, for HSV-1, clinical specimen #2
(TBT-IC.sub.50=0.25 .mu.g/ml);
[0032] FIG. 6 represents the analytical IC.sub.50 results for HSV-2
viral antigens, specifically for HSV-2 control (ATTC #VR-734 ,
Strain G), which demonstrated a TBT-IC.sub.50=0.75 .mu.g/ml;
[0033] FIG. 7 represents the analytical IC.sub.50 results for HSV-2
viral antigens, specifically for HSV-2, clinical specimen #3
(TBT-IC.sub.50=2.0 .mu.g/ml);
[0034] FIG. 8 represents the analytical IC.sub.50 results for HSV-2
viral antigens, specifically for HSV-2, clinical specimen #4
(TBT-IC50=0.25 .mu.g/ml);
[0035] FIG. 9 represents the analytical IC.sub.50 results for HSV-2
viral antigens, specifically for clinical specimen #5 (
TBT-IC.sub.50=0.5 .mu.g/ml); and
[0036] FIG. 10 represents the analytical IC.sub.50 results for
HSV-2 viral antigens, specifically for clinical specimen #6
(TBT-IC50<0.10 .mu.g/ml).
DETAILED DESCRIPTION OF THE INVENTION
[0037] The invention pertains to methods and pharmaceutical
compositions for preventing or treating viral infections in a
mammal, and the dermal or mucosal lesions or tumors caused by viral
infections in mammals including, but not limited to, human
herpesvirus infections (HHV), and more preferably primary or
recurrent HSV infections.
[0038] In one aspect of the invention, primary and recurrent
lesions, sores, or tumors of the skin and mucosa are treated with a
topical composition comprising an effective amount of an
anti-microtubule agent to a human suffering from herpesvirus
infections. The area to be treated may include, the lips, eyes,
mouth, genital and anal area, and other areas accessible to topical
administration, which may be the site of a herpes lesion, sore, or
tumor.
[0039] In a second aspect of the invention relates to a method of
treating or preventing herpesvirus infections using pharmaceutical
compositions that contain an effective dosage of an
anti-microtubule agent which is administered to a patient suffering
from viral infections, or at risk for contracting viral infections,
in order to treat or prevent the viral infection in the
patient.
[0040] In a third aspect of the invention, primary and recurrent
infections caused by a herpesvirus that may or may not be
associated with lesions, are treated with a pharmaceutical
composition or a combination of pharmaceutical compositions that is
used for regional or systemic administration of an inhibitory
effective amount of an anti-microtubule agent contained in the
pharmaceutical composition or anti-microtubule agents contained in
the combination of pharmaceutical compositions. These types of
infections would include viral caused neonatal diseases,
encephalitis diseases, and respiratory distress syndrome or
acuteonset bronchospasm diseases.
[0041] The pharmaceutical compositions of the invention contain an
antiviral agent. For the purpose of this invention, the antiviral
agent is any molecule from the pharmaceutical composition that
interferes with the normal structure and function of microtubule
dynamics within a host cell. The antiviral agent interferes with
the viability, production, or activity of tubulin proteins within a
host cell, including the promotion or inhibition of microtubule
polymerization, or the promotion or inhibition of microtubule
disassembly. Additionally, the antiviral agent may also exhibit
inhibitory effects upon MAPs that mediate the transport of viral
particles including a viral genome within the host cell.
[0042] The scope of the invention includes any pharmaceutical
composition that modifies the activity or effect of
microtubule-mediated cytoplasmic transport of viral particles,
either directly or indirectly, in decreasing the permissiveness of
cells to virus infection. The specific embodiments of this
invention as described herein are not intended to limit the
applicability of the principles involved. Those skilled in the art
are aware that there are, or may be, other means of modifying the
activity of microtubules.
[0043] The present invention provides pharmaceutical compositions
which may contain between 0.005% and 30%, (weight percentage) of
the antiviral agent as described above and of one or more of a
plurality of pharmaceutically acceptable excipients. Among the
plurality of pharmaceutically acceptable excipients include
lactose, dextrose, sucrose, sorbitol, mannitol, starches, gum
acacia, calcium phosphate, alginates, tragacanth, gelatin, calcium
silicate, mircrocrystalline cellulose, polyvinylpyrrolidone,
cellulose, sterile water, syrup and methyl cellulose.
[0044] The pharmaceutical compositions can additionally include:
lubricating agents such as talc, magnesium stearate and mineral
oil; wetting agents; emulsifying and suspending agents; preserving
agents such as methyl-benzoates and proplyhydroxy-benzoates;
sweetening agents and flavoring agents.
[0045] The invention can be formulated so as to provide quick,
sustained or delayed release of the antiviral agent after
administration to the patient by employing procedures known in the
art. Other components may be added to the pharmaceutical
composition based upon the related drug delivery system, to improve
the pharmacokinetics or pharmacodynamics of the composition.
[0046] In making the compositions of the invention, the antiviral
agent is usually mixed with and/or diluted by, one or more
excipients. Alternatively, the antiviral agent may be enclosed
within a carrier, in the form of a capsule or other container. As
the excipient may be solid, semi-solid, or liquid, the resultant
composition may also be solid, semi-solid, or liquid.
[0047] The pharmaceutical compositions of the present invention can
include other active ingredients. For instance, drugs that are
commonly used to treat herpes, such as nucleoside analogs, or pain
relieving drugs such as acetaminophen may be added to the
composition. Additionally, agents or chemical additives that
enhance the antiviral activity of the agent, or more than one
antiviral agent, can be included in the pharmaceutical composition.
It may also be desirable to include one or more penetrating agents,
such as dimethyl sulfoxide (DMSO), to convey the active ingredients
into the epidermal tissues.
[0048] Topical pharmaceutical compositions in the form of an
ointment, cream, gel, solution, lotion, emulsion, aerosol, powder,
or other topical vehicle, including a sponge, suppository or stick,
are designed and prepared such that a therapeutically effective
amount of the antiviral agent is brought into contact with diseased
tissue. An excipient or carrier may take a wide variety of forms
depending on the form of preparation desired for topical
administration, which includes rectal or vaginal administration. In
preparing pharmaceutical compositions in topical dosage form, any
of the usual pharmaceutical media may be used.
[0049] To create a viscous ointment, for example, de-ionized water,
oil and an emulsifier are intermingled to create an emulsion. An
oil suitable for such a purpose is petrolatum registered by the
United States Pharmacopia/National Formulary (USP/NF). A wax
suitable as an emulsifier is wax registered by the USP/NF. A
preservative ointment includes USP/NF registered methyl paraben or
propyl paraben and humectants, such as propylene glycol.
[0050] Solid compositions such as tablets, pills and capsules may
be prepared by mixing the antiviral agent with an excipient so that
the antiviral agent is evenly distributed throughout the
composition, thus making it possible to subdivide the composition
into equally effective doses.
[0051] The antiviral compositions of the present invention may be
incorporated into liquid forms to be administered orally or by
injection including aqueous or non-aqueous solutions, syrups,
aqueous or oil suspensions and emulsions comprising edible oils,
such as corn oil, as well as tinctures and similar pharmaceutical
vehicles.
[0052] Compositions for inhalation may include solutions and
suspensions in pharmaceutically acceptable, aqueous or organic
solvents or powders. The liquid or solid compositions may contain
pharmaceutically acceptable excipients as described herein.
Administration of the compositions through the oral or nasal
respiratory tract is preferred for local or systemic effect.
[0053] Although certain preferred embodiments of the invention have
been described herein, these are not meant to limit the invention,
which covers all alternatives, modifications and equivalents as may
be included within the scope of this invention. The preferred
embodiments presented herein are represent sent the most useful
embodiments of the invention, as well as a description of the
underlying principles and conceptual aspects of the invention.
[0054] Treatment with the pharmaceutical compositions of this
invention may begin when a patient has been exposed to a virus,
when symptoms of infection, such as epidermal lesions, are apparent
in a patient, or when a patient is diagnosed with an active viral
infection. Treatment should be continued until risk of infection is
over or until the active symptoms of the viral infection have
subsided.
[0055] As will be apparent to those skilled in the art, various
modifications, adaptations and variations of the preceding and
foregoing specific disclosure can be made without departing from
the scope of the invention claimed herein. The following examples
are intended only to illustrate and describe the invention rather
than limit the claims which follow.
[0056] The herpes simplex viruses, including HSV-1 (oro-facial) and
HSV-2 (genital herpes), present a serious problem for millions of
people worldwide. To the best of applicant's knowledge, until now,
an effective, economical, and readily available topical treatment
has not existed.
[0057] Herpes simplex virus is a common, recurrent, and chronic
infection. It is estimated that at least 75% of the world's
population has been infected with HSV-1 and more than 20% with
HSV-2. Although the majority of cases are asymptomatic, chronic
outbreaks of lesions are very common, usually occurring in mucous
membrane areas and the surrounding skin. The most common of these
lesions occur on the lips or face and are commonly referred to as
"cold sores" or "fever blisters." Genital herpes lesions occur on
the genitals and buttocks and are particularly troubling because of
their possible role in contributing to the spread of HIV.
[0058] Herpes lesions first appear as an area of irritation (an
itching or burning sensation) known as the prodromal stage. Within
a few hours, these lesions develop into small vesicles or blisters.
Typically, these vesicles soon rupture and form shallow ulcerations
which may scab over and heal in about ten to twenty days. The
ruptured vesicles may also cause secondary infections and spread
the virus to the surrounding tissue.
[0059] After initial exposure to the herpes simplex virus, the host
develops antibodies that can maintain the virus in a latent state.
Despite the presence of antibodies, the latent virus may be
reactivated by stress, exposure to sunlight, fever, hormonal
changes, menstruation, and trauma. Eruptions can occur randomly and
may persist for weeks.
[0060] Research supported in part by the National Institute of
Allergy and Infectious Diseases (and conducted by virologists at
the University of Chicago and the University of Alabama, has
demonstrated that compounds comprising at least one antimicrotubule
agent possess clinically significant anti-viral properties that
specifically inhibit replication of HSV-1 and HSV-2 in vitro.
[0061] There is currently no known cure for herpes simplex virus
infections. However, a topical therapy that delivers
clinically-demonstrated, anti-viral compositions to the affected
area, inhibiting viral replications in the lesions, accelerating
healing of the existing lesion, and preventing the spread of
secondary infections, would be of enormous benefit to the herpes
sufferer.
[0062] In one embodiment, the present invention provides
compositions useful for treating diseased, biological tissue, such
as the epidermis or mucous membranes, in a mammal. The methods and
compositions of the present invention are effective in treating
viral infections, dermal or mucosal lesions, inflammation, or
tumors associated with said viral infections. The compositions of
the present invention include at least one anti-microtubule agent.
The anti-microtubule agent can be a naturally occurring compound, a
semi-synthetic compound, or can be an entirely synthetic compound
that is chemically synthesized by any means known to those skilled
in the art.
[0063] Examples of compounds that have been identified as
anti-microtubule agents include, but are not limited to, taxanes
and taxoids, discodermolide, epothilones A and B, eleutherobin,
taccalonolide, colchicine, colcemid, demecolcine, the vinca
alkaloids including vincrisitine, vinepidine, vindesine,
vinblastine, vinorelbine, desformyl vincrisitine, desacetyl
desformyl vincristine, and vinflunine, phomopsin A, ustiloxins,
cryptophycins, halichondrins, estramustine, rhizoxin, nocodazole,
and any analogues or derivatives of any of the above.
[0064] A presently preferred composition of the present invention
is formed from an extract from the Pacific Yew tree (Taxus
brevifolia) combined with virgin olive oil and beeswax. The T.
brevifolia extract is extracted by the method set forth in Example
1 herein and combined with olive oil at a ratio of about 1:1. The
ethanol and water (from the extract) are completely evaporated
before combining with the beeswax at a ratio of about 6:1. High
Performance Liquid Chromatography (H.P.L.C.) analysis of the
foregoing T. brevifolia extract revealed the presence of 8.1
.mu.g/ml paclitaxel, 77.87 .mu.g/ml cephalomannine, and 623.79
.mu.g/ml 10-deacetyl-7-xylosyltaxol, plus some other taxanes
present in minor amounts. Preferably, the compositions of the
present invention are topically applied in the form of an ointment,
salve or lotion to the site of disease. Compositions of the present
invention can be mixed with other physiologically acceptable
components, such as carriers, stabilizers or antioxidants, to form
an ointment, salve or lotion having desirable physical and chemical
properties, and consistency. See, Remington's Pharmaceutical
Sciences, 16th Edition, Osol, A., Ed (1980).
[0065] Preferably, compositions of the present invention include at
least one anti-microtubule agent in an amount of from about 0.005%
to about 30% of the total weight of the composition. Preferably,
the compositions of the present invention also include a natural
oil such as, but not limited to, olive oil, mineral oil, corn oil,
sunflower oil, peanut oil, and fish oil. Preferably, the
compositions of the present invention also contain a wax such as,
but not limited to, beeswax, U.S.P. Carbowax 5000.RTM., U.S.P.
Carbowax 6000.RTM. (the foregoing Carbowax.RTM. products are
manufactured by Union Carbide Corporation, World Headquarters, 39
Old Ridgebury Road, Danbury, and Conn. 06817-001) and
petrolatum.
[0066] In addition to the foregoing components, compositions of the
present invention can include additional ingredients including, but
not limited to, analgesics and anesthetics.
[0067] The compositions of the present invention, when applied
topically, soothe the discomfort associated with viral lesions and
other epidermal conditions, prevent the lesion from cracking or
bleeding, reduce the time to healing, and prevent the spreading of
viral infections by effectively inhibiting viral replication.
[0068] In another embodiment, the present invention includes a
method of treating diseased biological tissue, such as the
epidermis or mucous membranes, in a mammal. The method of the
present invention includes the step of contacting a diseased
biological tissue, such as the epidermis, with a composition of the
present invention containing an amount of an antimicrotubule agent,
or related compound, that is effective to ameliorate the disease
symptoms. The methods and compositions of the present invention are
effective in treating viral infections, dermal or mucosal lesions,
inflammation, or tumors associated with said viral infections.
Examples of viral infections that can be treated using the
compositions and method of the present invention include, but not
limited to, HSV-1, HSV-2, HSV-6, HSV-7, HSV-8, VZV, CMV, EBV, and
PPV.
[0069] The compositions of the present invention should be applied
directly to the affected portion of the mammalian body, such as the
epidermis. Preferably, in the practice of the method of the present
invention, the quantity of a composition of the present invention
that is applied to an affected bodily surface is sufficient to
cover the affected area. A sufficient quantity of a composition of
the present invention should preferably be reapplied as often as is
necessary to keep the affected area covered until the condition has
completely cleared. In the case of viral infections such HSV-1 or
HSV-2, a composition of the present invention should be applied at
the very first (prodromal) indication of symptoms (i.e., burning,
itching, or tingling sensations). Such early application will, in
many cases, prevent lesions from fully developing or spreading,
thus significantly limiting the time to healing, discomfort, risk
of further infection to self and others, and risk of infection from
other opportunistic viruses such as HIV.
[0070] The following examples merely illustrate the best mode now
contemplated for practicing the invention, but should not be
construed to limit the invention. Examples 1 and 2 describe methods
of manufacture of various forms of the preferred embodiment.
Examples 4-6 describe the clinical effectiveness of preferred
embodiments applied to patients infected with HSV-1 and HSV-2.
Examples 7 and 8 demonstrate the specific anti-viral activity that
Taxus brevifolia Tinctures (TBT) exhibits in various viral infected
cell culture systems.
EXAMPLE 1
[0071] Extraction of Naturally-Occurring Taxanes from Yew
[0072] Needles and branches of yew tree species are harvested by
pruning the terminal branch tips of the selected species in such a
way as to encourage new growth and preserve the tree for future
harvesting, thus maintaining the existing biomass as a fully
renewable resource. The material is then milled in order to
increase the amount of exposed surfaces and render the material
more compact. One part (by weight) of the material is placed in a
suitable container and saturated with two parts (by weight) of
ethanol (or other suitable solvent such as isopropyl alcohol,
butanol, or methanol in concentrations ranging from 5% to 100%).
The resulting mixture is allowed to macerate in the solvent for a
specific time (typically 7 to 14 days) until the material is
exhausted of its constituents, and then is hydraulically pressed
and filtered to remove the residue of plant material.
EXAMPLE 2
[0073] Second Exemplary Method for Extraction of
Naturally-Occurring Taxanes from Yew
[0074] The raw materials are harvested as described in Example 1
and placed in a columnar percolator. The material may be
pre-moistened for several hours in a fraction of the solvent and
then passed through a coarse sieve and lightly packed in the
chamber, with a wad of gauze below and filter paper above. The
drain is closed and sufficient solvent is added to cover the
material. The vessel is then covered and allowed to macerate for
approximately 24 hours. The drain is then opened and fluid is
allowed through at the rate of 10 to 30 drops per minute, solvent
being added to the top as needed until the material is exhausted.
The material is then hydraulically pressed to extract any remaining
fluid which is then added to the percolate.
EXAMPLE 3
[0075] Effectiveness of the Compositions of the Present Invention
in Treating Cold Sores
[0076] An adult female, suffering from severe, recurrent HSV-1
infections, applied the presently preferred composition of the
invention to a labial infection (cold sore) after it had developed
into a large blister (the presently preferred composition of the
invention is a salve prepared from a T. brevifolia extract,
prepared by the method set forth in Example 1 herein, which is
combined with olive oil at a ratio of about 1:1. The ethanol and
water (from the extract) are completely evaporated before combining
T. brevifolia extract and olive oil with beeswax at a ratio of
about 6:1.). The composition was reapplied regularly as needed to
keep the blister covered. The blister disappeared within 24 hours
and was replaced by healthy tissue. Several months later, the
subject experienced prodromal symptoms (i.e., tingling and itching)
and applied the compound immediately. Again, the composition was
reapplied regularly for 24 hours. The infection did not progress
further and produced no lesion or other evidence of infection.
EXAMPLE 4
[0077] Effectiveness of the Compositions of the Present Invention
in Treating Genital Herpes in a Female Subject
[0078] An adult female, suffering from mild, recurrent HSV-2
infections that typically produced lesions on the genitalia lasting
approximately 7 days, applied the presently preferred composition
of the present invention to the affected parts immediately upon
experiencing prodromal symptoms. The infection did not progress
further and produced no lesions or other evidence of infection.
EXAMPLE 5
[0079] Effectiveness of the Compositions of the Present Invention
in Treating Genital Herpes in a Male Subject
[0080] An adult male, suffering from moderately severe, recurrent
HSV-2 infections that typically produced lesions on the genitalia
lasting approximately 7 to 10 days, applied the presently preferred
composition of the invention to the affected parts immediately upon
experiencing prodromal symptoms. The composition was reapplied
regularly as needed to keep the affected area covered. The
prodromal symptoms were resolved within 48 hours. The infection did
not progress further and produced no lesions or other evidence of
infection.
EXAMPLE 6
[0081] Effectiveness of the Compositions of the Present Invention
in Treating Genital Herpes in a Male Subject
[0082] An adult male, suffering from moderately severe, recurrent
HSV-2 infections that typically produced lesions on the genitalia
lasting approximately 8 days, applied the presently preferred
composition of the invention to the affected parts immediately upon
experiencing prodromal symptoms. Some lesions did appear and the
composition was reapplied regularly as needed to keep the affected
area covered. All symptoms were resolved within 4 days.
EXAMPLE 7
[0083] Screening Assays for Activity of TBT (ARB ID# 980332)
Against HSV-1, HSV-2, CMV, VZV, and EBV
[0084] The data below, discloses the results of ELISA assays
demonstrating the effectiveness of the Taxus Brevifolia Tinctures
(TBT) extracts (Lot ARB-ID# 99-332) of Example 1 against Herpes
Simplex Virus-1 (HSV-1).
[0085] General Approach for Determining Antiviral Activity and
Toxicity
[0086] A. Screening Assays for Activity Against HSV-1, HSV-2, CMV,
and VZV
[0087] All the screening assay systems utilized have been selected
to show specific inhibition of a biologic function, i.e.,
cytopathic effect (CPE) in susceptible human cells. In the CPE,
inhibition assay, drug is added 1 hr prior to infection so the
assay system will have maximum sensitivity and detect inhibitors of
early replicative steps such as absorption or penetration as well
as later events. To rule out non-specific inhibition of virus
binding to cells all compounds that show reasonable activity in the
CPE assay are conformed using a classical plaque reduction assay in
which the drug is added 1 hr after infection. In the case where a
compound blocks attachment, it will show up positive in the CPE
assay, but may be negative by plaque assay. In this case, the
plaque assay is repeated with drug being added prior to viral
infection. Using this approach, we have been able to identify
compounds that inhibit virus absorption. These assay systems also
can be manipulated by increasing the pretreatment time in order to
demonstrate antiviral activity with oligodeoxynucleotides and/or
peptides and by delaying addition of drug after infection,
information regarding which step in the virus life cycle is
inhibited (i.e., early vs. late functions) can be gained.
[0088] 1. Efficacy. In all the assays used for primary screening, a
minimum of six drug concentrations were used covering a range of
100 .mu.g/ml to 0.03 .mu.g/ml, in 5-fold increments. From these
data, we calculate the dose that inhibits viral replication by 50%
(effective concentration 50; EC.sub.50) using the computer software
program MacSynergy II by M. N. Prichard, K. R. Asaltine, and C.
Shipman, Jr., University of Michigan, Ann Arbor, Mich.
[0089] 2. Toxicity. The same drug concentrations used to determine
efficacy are also used on uninfected cells in each assay to
determine toxicity of each experimental compound. The drug
concentration that is cytotoxic to cells as determined by their
failure to take up a vital strain, neutral red, (cytotoxic
concentration 50; CC.sub.50) was determined as described above. It
is very important to determine the toxicity of new compounds on
dividing cells at a very early stage of testing. We have found that
a cell proliferation assay using human foreskin fibroblasts (HFF)
cells is a very sensitive assay for detecting drug toxicity to
dividing cells and the drug concentration that inhibits cell growth
by 50% (IC.sub.50) is calculated as described above. In comparison
with four human diploid cell lines and vero cells, HFF cells are
the most sensitive and predictive of toxicity for bone marrow
cells.
[0090] 3. Assessment of Drug Activity. To determine if each
compound has sufficient antiviral activity that exceeds its level
of toxicity, a selectively index (SI) is calculated according to
CC.sub.50/EC.sub.50. This index, also referred to as a therapeutic
index, was used to determine if a compound warrants further study.
For these studies, a compound that had an SI of 10 or greater was
evaluated in additional assay systems.
[0091] B. Confirmation of Antiviral Activity and Toxicity for HSV,
CMV and VZV
[0092] 1. HSV-1 and HSV-2. Compounds that showed activity in the
CPE-inhibition assay was confirmed using the plaque reduction assay
as described in an earlier section. Susceptibility of additional
virus strains including both lab passaged and clinical isolates was
determined for selected compounds. A battery of ACV resistant HSV
strains were also utilized.
[0093] 2. CMV. Compounds that have activity in the CPE-inhibition
assay were confirmed using the plaque reduction assay in HFF cells.
A variety of laboratory, clinical, and GCV resistant isolates are
also available for testing.
[0094] 3. VZV. Compounds were tested for activity in a plaque
reduction assay. A battery of laboratory, clinical, and
ACV-resistant isolates are available.
[0095] 4. Toxicity. In addition to the toxicity component
incorporated into each assay system, a standardized cell
cytotoxicity assay using a vital strain uptake (Neutral Red) was
performed using 7 days of drug exposure to confluent non-dividing
cells. This assay measures direct cell killing (CC.sub.50).
Inhibition of cell growth (IC.sub.50) can also be determined by
treatment of proliferating cells and then assessing the amount of
dye uptake.
[0096] C. Assay Systems for Determining Antiviral Activity Against
EBV and Toxicity to Lymphoblastic Cells
[0097] 1. Superinfection of susceptible Burkitt's Lymphoma (BL)
cells with P3HR-1 virus followed by analysis of specific EBV gene
product expression using monoclonal antibodies provides a
convenient and repeatable system of evaluate inhibition of EBV gene
expression during early and late stages of the virus replication
cycle. We can evaluate diffuse (D) and restricted (R) early
antigens (EA) as well as viral capsid antigen (VCA) by fluorescence
microscopy and by fluorescence flow cytometry.
[0098] 2. Screening Assay for EBV Activity. The initial system to
be used to determine antiviral activity against EBV will be VCA
production Daudie cells using an immunofluorescence assay (IFA). As
in all the other assays, six concentrations of drug covering a
range of 100 .mu.g/ml to 0.03 .mu.g/ml will be utilized. Using the
results obtained from untreated and drug treated cells an EC.sub.50
can be calculated. Selected compounds that have good activity
against EBV VCA production without toxicity will be tested for
their ability to inhibit EBV DNA synthesis.
[0099] 3. Toxicity. In each assay system utilized, drug treatment
of uninfected cells is incorporated to obtain as much toxicity data
as possible.
[0100] 4. Confirmation of drug activity against EBV DNA production
using in situ DNA hybridization assay. All compounds that have an
SI>10 in the screening assay or ones selected by the project
offer will be confirmed in a hybridization assay that measures the
amount of EBV DNA produced by P3HR-1 infected cells. As in all
other assay systems utilized, a wide range of drug concentrations
will be utilized so an accurate EC.sub.50 can be calculated.
Uninfected control cells treated with drug will also be utilized as
another measure of drug toxicity.
[0101] a. Infection and drug treatment: 106 cells/tube are infected
with EBV at a dilution of 1:40. After incubation for 45 minutes at
37.degree. C., 3 ml of RPMI, a cell culture media, is added and the
cells pelleted by centrifugation. The supernatant was then
discarded and the cells resuspended in 4 ml of RPMI needing
containing various concentrations of drug. After incubation for 48
hours, the cells are counted in each tube, washed with PBS and
spotted on slides. The slides are left to air-dry overnight and
then fixed in acetone for 10 minutes at room temperature.
[0102] b. DNA hybridization: The biotin labeled EBV probe is added
to each spot and the slide is covered with a glass overslip. The
slide is then heated on a hot plate at 95.degree. C. for three
minutes. After heating, the slide is left to sit at room
temperature for 20 minutes, for the DNA to anneal. The overslips
are then removed and the Post Hybridization Reagent is added to
each spot. After incubation for 10 minutes and rinsing with washing
buffer, Detection Reagent is applied. This is left on for 20
minutes at room temperature and then washed off with washing
buffer. Chromagen Substrate Solution is added and incubated for 10
minutes at room temperature. Washing buffer is used to rinse it
off, and the slides are counter stained for 30-60 seconds with fast
Green stain. The slides are then rinsed with deionized water and
mounted with water.
[0103] C. Reading and calculation of results: The slides are viewed
in a light microscope under a magnification of 100-400. Positive
cells appear as pink or red spots. All the cells are counted in
several fields. The fraction of red spots in the total number of
cells counted multiplied by 100 reflects the percent of
hybridization.
EXAMPLE 8
[0104] ELISA Testing Of HSV Susceptibility To TBT
[0105] The data below discloses the results of ELISA assays
demonstrating the effectiveness of the T. brevifolia tincture
extracts of Example 1 against Herpes Simplex Virus (HSV).
Susceptibility Testing by ELISA (Enzyme Linked Immunosorbent
Assay)
[0106] HFF cells were inoculated into 96-well microtiter trays at a
density of 7.times.10.sup.3 cells per well. The plates were
incubated at 37.degree. C. in 5% CO.sub.2 until the cells were
confluent, usually three days. Sixty wells of each plate were used:
six uninfected cell control wells, six virus-infected control wells
without drug, and six replicates of eight dilutions of the drug.
Dilutions of each virus were prepared in minimal essential media
(MEM). The growth medium was removed from all wells and 50 .mu.l of
MEM was added to the cell control wells and 50 .mu.l of virus
inoculum with a multiplicity-of-infection (MOI).about.0.05, was
added to the remaining wells. The virus was allowed to absorb for
one hour at 37.degree. C. The inoculum was removed and 100 .mu.l of
MEM was added to the cell control wells and the virus control
wells. Eight dilutions of Taxus brevifolia Tincture (TBT) were
prepared in MEM and 100 .mu.l of the diluted drug was added to the
remaining wells beginning at a 4.0 .mu.g/ml through a 0.1 .mu.g/ml
of the drug. All plates were incubated at 37.degree. C. in 5%
CO.sub.2.
[0107] After incubating for 48 hours, the plates were examined
using an inverted phase contrast microscope to insure that viral
CPE was present in the virus control wells and to score the CPE in
all wells of the plate including the virus control wells and all
drug dilution wells. Each row of wells was scored from 0 to 4+ and
4+ indicated that all cells showed CPE. This was done to insure
that the inhibition of CPE correlated with the quantitative ELISA
results. The medium was then removed from all microtiter wells and
100 .mu.l of a blocking solution consisting of 0.5% bovine serum
albumin (BSA) in phosphate buffered saline (PBS), pH 7.2, was added
to each well for 30 min. at room temperature. The blocking solution
was removed, the cells were fixed by adding 100 .mu.l of
ethanol/acetone (95:5, v/v) to each well and the plates were placed
at -20.degree. C. for 30 min. Each well was washed four times with
200 .mu.l of wash solution (PBS containing 0.5% BSA and 0.05% Tween
20).
[0108] The antibodies used in ELISA were obtained from Dako
Corporation, Carpinteria, Calif., and were prepared by immunizing
rabbits with an antigen prepared by sonication and extraction of
HSV-1 or HSV-2 infected rabbit cornea cells. All the virion
proteins were present in the antigen preparation used to produce
the antibody. To determine the inhibitory concentration
(IC.sub.50), the rabbit polyclonal antibody to HSV-1 or HSV-2
conjugated to horseradish peroxidase was diluted in PBS containing
10% normal rabbit serum. A volume of 100 .mu.l of the antibody was
added to each well and the plates were incubated at 37.degree. C.
for two hours. The antibody was removed and the wells were washed
four times as before. The enzyme substrate, 3, 3', 5,
5'--tetramethylbenzidine (TMB, Sigrna, ST. Louis, Mo.) was added to
each well and the plates were incubated at room temperature for 3-4
minutes. The O.D. was determined for the uninfected cell control
wells, the virus control wells, and each drug dilution. The percent
change in O.D. was calculated as follows: (average drug sample
O.D.--average cell control O.D.)/(average virus control
O.D.--average cell control O.D.).times.100. The IC.sub.50 is
defined as the dilution of antiviral compound that produces a 50%
or greater reduction in the O.D. of the colored substrate
product.
[0109] While the preferred embodiment of the invention has been
illustrated and described, as noted above, many changes can be made
without departing from the spirit and scope of the invention.
Accordingly, the scope of the invention is not limited by the
disclosure of the preferred embodiment.
* * * * *