WO2003002126A1

WO2003002126A1 - Anti-retroviral agent in combination with tea polyphenol for the treatment of viral infections

Info

Publication number: WO2003002126A1
Application number: PCT/IB2002/002399
Authority: WO
Inventors: Zeno Apostolides; Modiegi Selematsela
Original assignee: University Of Pretoria; Tokyo Food Techno Company Limited
Priority date: 2001-06-28
Filing date: 2002-06-25
Publication date: 2003-01-09

Abstract

A combination dosage for use in the treatment of a viral infection, comprises at least one anti-retroviral agent and at least one tea polyphenol compound. The combination dosage is optionally in the form of two separate formulations or compositions in which the anti-retroviral agent is contained in one formulation or composition and the tea polyphenol compound is contained in the other formulation or composition. The anti-retroviral agent is preferably 3'-azido-3'-deoxythymidine and the tea polyphenol compound is selected from tea catechins, theaflavins, thearubigins and combinations thereof.

Description

ANTI-RETROVIRAL AGENT IN COMBINATION WITH TEA POLYPHENOL FOR THE TREATMENT OF VIRAL INFECTIONS

THIS INVENTION relates to the treatment of a viral infection.

The invention relates, in particular, to a combination dosage for the treatment of a viral infection, to a dosage kit, to a substance or composition for use in the treatment of a viral infection, to the use of a substance or composition in the manufacture of a medicament for the treatment of a viral infection and to a method of treating a viral infection.

The invention provides a combination dosage for use in the treatment of i a viral infection, the combination dosage comprising a first component which is an anti-retroviral agent and a second component which is a tea polyphenol compound or a mixture of tea polyphenol compounds.

In particular, the invention provides a combination dosage for use in the treatment of a viral infection, the combination dosage comprising at least one anti- retroviral agent and at least one tea polyphenol compound.

The first and second components may be provided in separate formulations or compositions or they may be provided as a single formulation or composition. Accordingly, the combination dosage may include two separate formulations or compositions in which the at least one anti-retroviral agent is contained i in one formulation or composition and the at least one tea polyphenol compound is contained in the other formulation or composition. Instead, the at least one anti- retroviral agent and the at least one tea polyphenol compound may be contained in a single formulation or composition. The anti-retroviral agent may be AZT (zidovidine or 3'-azido-3'- deoxythymidine) .

The second component may be a tea polyphenol compound or a mixture of tea polyphenol compounds selected from the group consisting of tea catechins, theaflavins, thearubigins and combinations thereof. The at least one tea polyphenol compound may thus be selected from the group consisting of tea catechins, theaflavins, thearubigins and combinations thereof.

In particular, the at least one tea polyphenol may be selected from epigallocatechin gallate (EGCg), epicatechin gallate (ECg), epigallocatechin (EGC),

» gallochatecin (GC), epicatechin (EC), epicatechin gallate (ECg), catechin (C), catechin gallate (Cg), theaflavin, theaflavin digallate, theaflavin monogallate, caffeine, theanine and combinations of any two or more thereof.

Preferably, the tea polyphenol will be selected from catechins or dimers or polymers thereof namely theaflavins and thearubigins. More preferably, the i polyphenol will be selected from C, Cg, EC, ECg, EGC, EGCg, GC, GCg and combinations of any two or more thereof.

The second component may, instead, be a polyphenol-containing extract of the plant Camellia sinensis. The at least one tea polyphenol compound may thus be obtained by extracting the plant Camellia sinensis.

I The dosage may contain between about 20 and 300 mg of AZT and preferably between about 80 and 1 50 mg of AZT. More preferably the dosage may contain about 100 mg of AZT. The amount of AZT administered per day is preferably between about 1 and 1 70 mg/kg body weight/day of AZT and more preferably between about 5 and 51 mg/kg body weight/day.

i The dosage may contain between about 4 and 300 mg of the tea polyphenol compound or mixture of tea polyphenol compounds and preferably between about 1 0 and 1 00 mg of the tea polyphenol compound or mixture of tea polyphenol compounds. More preferably the dosage may contain about 50 mg of the tea polyphenol compound or mixture of tea polyphenol compounds. The preferred amount of the tea polyphenol compound or mixture of the tea polyphenol compounds administered per day is between about 1 and 2000 mg/kg body weight/day and preferably between about 70 and 600 mg/kg body weight/day.

The viral infection may be an immunodeficiency viral infection such as HIV infection which causes AIDS (acquired immunodeficiency syndrome) . It may instead be a murine leukemia viral infection which causes murine acquired immunodeficiency syndrome or MAIDS.

The invention also provides a dosage kit for use in the treatment of a viral infection, the dosage kit comprising a first component which is an anti-retroviral agent and a second component which is a tea polyphenol compound or a mixture of tea polyphenol compounds.

More particularly, according to another aspect of the invention there is provided a dosage kit for use in the treatment of a viral infection, the dosage kit comprising at least one anti-retroviral agent and at least one tea polyphenol compound.

The dosage kit may contain separate dosage forms respectively containing the anti-retroviral agent and the second component. The dosage form may be in the form of a solid, a liquid or a spray. It may for example be a solution, a powder, a tablet, a capsule or the like and may include an excipient. It may instead be in the form of a drip or an ointment or injectable form. The route of administration may be enteral (sublingual, per os (p.o.), mouth-spray, per rectum (pr)) or parenteral (intravenous, intra- muscular, subcutaneous implants, local application or inhalation) or intra-lumenal administration.

Instead, the dosage kit may include a single dosage form which contains the at least one anti-retroviral agent and the at least one tea polyphenol compound. The anti-retroviral agent and the tea polyphenol compound may be as hereinbefore described. The amounts of the anti-retroviral agent and the tea polyphenol compound may be as hereinbefore described.

The invention also provides a substance or composition for use in the treatment of a viral infection, the substance or composition comprising, in combination, a first component which is an anti-retroviral agent and a second component which is a tea polyphenol compound or a mixture of tea polyphenol compounds.

Thus, according to another aspect of the invention, there is provided a substance or composition for use in the treatment of a viral infection, the substance or composition comprising at least one anti-retroviral agent and at least one tea polyphenol compound.

The anti-retroviral agent and the tea polyphenol compound may be as hereinbefore described.

The invention further provides the use of a substance or composition in the manufacture of a medicament for the treatment of a viral infection, the substance or composition comprising, in combination, a first component which is an anti- retroviral agent and a second component which is a tea polyphenol compound or a mixture of tea polyphenol compounds.

Thus according to another aspect of the invention, there is provided the use of a combination of substances or compositions in the manufacture of a dosage form for the treatment of a viral infection, the substances or compositions comprising at least one anti-retroviral agent and at least one tea polyphenol compound.

The dosage form may be a single composition which contains the at least one tea polyphenol compound and the at least one anti-retroviral agent. Instead, the dosage form may comprise separate compositions which respectively contain the at least one tea polyphenol compound and at the least one anti-retroviral agent.

The anti-retroviral agent and the tea polyphenol compound may be as hereinbefore described. The amounts of the anti-retroviral agent and the tea polyphenol compound may be as hereinbefore described.

Tea catechins and theaflavins, that are the dimers of catechins, are polyphenols which have strong antioxidative and free radical scavenging action.

The tea polyphenols will typically be obtained by the extraction of fresh leaves of Camellia sinensis unfermented and dried (green tea), semi-fermented and ' dried (oolong tea) or fermented and dried (black tea) or the undried versions of the above three teas or leaves.

The tea polyphenol may, instead, be the substance marketed as Polyphenon by the Tokyo Food Techno Co. Ltd of Japan. This product typically contains ( + )-gallocatechin (1 .4 %), (-)-epigallocatechin ( 1 7.6%), (-)-epicatechin (5.8%), (-)epigallocatechin gallate (53.9%), (-)-epicatechin gallate (1 2.5%) and caffeine (0.5%) and traces of theanine.

The invention also provides a method of treating a viral infection, the method including the step of administering to a person or animal in need of treatment a first component which is an anti-retroviral agent and a second component which is ι a tea polyphenol compound or a mixture of tea polyphenol compounds.

Thus, according to another aspect of the invention, there is provided a method of treating a viral infection, the method including administering to a person or animal in need of treatment, at least one anti-retroviral agent and at least one tea polyphenol compound. The method may include administering the at least one anti-retroviral agent and the at least one tea polyphenol compound in a single formulation or composition. Instead, the method may include administering the at least one anti- retroviral agent and the at least one tea polyphenol compound in separate formulations or compositions.

The method may include administering the anti-retroviral agent in an amount of between about 1 and 1 70 mg/kg body weight/day and preferably between about 5 and 51 mg/kg body weight/day.

The method may include administering the tea polyphenol compound or compounds in an amount of between about 1 and 2000 mg/kg body weight/ day and preferably in an amount of between about 70 and 600 mg/kg body weight/day.

The anti-retroviral agent may be administered enterally or parenterally. The tea polyphenol compound or compounds may be administered enterally or parenterally.

According to another aspect of the invention, in a method for treating a viral infection in a patient which comprises administering to a patient an effective amount of an anti-retroviral agent, there is provided the improvement which comprises also administering an effective amount of a tea polyphenol compound to the patient.

The tea polyphenol may be as hereinbefore described.

The method of administration may be as hereinbefore described. The invention thus describes a method of increasing the efficacy of anti-retroviral agents or drugs. DISCUSSION

Acquired immunodeficiency syndrome (AIDS) is a clinical disorder representing the end point in a progressive sequence of immunosuppressive changes that render the body highly susceptible to tumours and opportunistic infections. The replication and pathogenesis of HIV-1 has been extensively studied since it was first recognized as the agent responsible for causing AIDS. The enzyme HIV reverse transcriptase (HIV-RT) has been considered to be one of the appropriate targets for chemotherapeutic approaches toward AIDS. The enzyme exhibits a number of features that makes it an attractive target. It is crucial for viral replication.

i The drug zidovudine (AZT), a synthetic thymidine analogue (3'-azido-3'- deoxythimidine), has been used clinically in the management of AIDS. The drug is an effective anti-viral agent due to its ability to block HIV-RT activity. Long-term suppression chemotherapy appears to improve the survival of patients with AIDS, but its toxicity renders it unsuitable for long-term chemotherapy. The major AZT-related i toxicity is bone marrow suppression, which limits the dose and duration of the drug that can be used.

The recognition of AIDS as a retrovirus-induced disease and the difficulties encountered in developing an understanding of host-virus interactions in this disorder have encouraged increased interest in animal models of the disease. One of ⁾ these models, is MAIDS (murine acquired immunodeficiency syndrome) which is induced by the Duplan strain of MuLV (murine leukemia virus) . This strain consists of a replication competent B-tropic ecotropic (LP-BM5-eco), a B-tropic mink cell focus forming (MCF) murine leukemia virus (MuLV) and a replication defective virus (LP-BM5- def).

i Adult C57BL/6 mice infected with a mixture of murine leukemia viruses show many similarities to human immunodeficiency type-1 (HIV-1 ) infection including lymphadenopathy and splenomegally related to polyclonal activation of T and B cells to mitogenic and antigenic stimuli. Continuous administration of AZT in LP-BM5 MuLV immunodeficient virus-infected mice was found to be associated with the development of anemia, neutropenia, and thrombocytopenia similar to haematotoxicity symptoms found in humans. These problems have led to the need for alternative drugs for HIV therapy. The invention demonstrates the efficacy of combination therapy with standard anti-HIV drugs and extracts from the leaves of Camellia sinensis. The two major components of Camellia sinensis are (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg).

It has now been found that low non-toxic doses of EGCg combined with i AZT increases the efficacy of AZT monotherapy. In addition, the use of this combination therapy is beneficial to HIV patients because it reduces the toxicity and cost of AZT monotherapy.

The invention is now described, by way of example, with reference to the following Example, the Tables and Figure 1 which is a graph showing percentage survival as a function of time.

EXAMPLE

Zidovudine capsules (containing > 90% AZT) were used for treating the animals. Polyphenon E was obtained from the Tokyo Food Techno Co. Ltd, Japan.

Polyphenon E typically comprises ( + )-gallocatechin (1 .4 %), (-)-epigallocatechin i (1 7.6%), (-)-epicatechin (5.8%), (-)epigallocatechin gallate (53.9%), (-)-epicatechin gallate (1 2.5%), caffeine (0.5%) and traces of theanine.

Female 5-7 weeks old C57BL/6 mice were housed in microisolator cages in a humidity and temperature controlled environment and were fed with standard mice feed and water ad libitum. Cages, bedding, and food were autoclaved prior to use and i all cage changes and animal handling were performed in laminar airflow cabinets to protect the animals from opportunistic infections. Ventilation and airflow in the animal facility was set to twelve changes per hour. Room temperature was regulated at 20 degrees C and the rooms were set on automatic twelve-hour light and dark cycles with the light period beginning at 6h00. The animals were randomly assigned to the 8 therapy groups as shown in Table 1 , by using the PLAN procedure of the SAS software package (SASR User's Guide: Statistics, Version 5 Edition. Cary, NC: SAS Institute Inc., 1 985) . The LP-BM5 cell line was obtained from the University of Kentucky and was kept at -70°C until used. The LP-BM5 cells were grown to approximately 90-95% confluency in three or four days without changing the media. After 1 3 passages, the supernatant from each flask was decanted and all the cellular debris were removed by centrifugation at 2000 rpm for 10 minutes and then passed through 0.45 micron Millipore filters. The cell free, 0.45 micron filtered LP-BM5 cell supernatant was then administered to mice by intraperitoneal injection of 0.4 ml.

The effectiveness of AZT and EGCg therapy alone or in combination, as anti-retroviral treatment in LP-BM5MuLV infected mice was measured by following the survival of the animals for up to 34 weeks and by measuring body weights of the animals from the beginning of the experiment until week 21 . AZT and EGCg either alone or in combination were administered in the drinking water at a concentration of 0.25 mg/ml and 1 .0 mg/ml respectively for the duration of the experiment, beginning twenty-four hours after inoculation. This is equivalent to approximately 50 mg/kg body weight/day AZT and 200 mg/kg body weight/day EGCg. This AZT dose is normally used in the MAIDS model and is similar to the dose for human AIDS patients (200 mg every four hours or 1 7 mg/kg body weight/day).

The dose of tea normally used in animal experiments is 1 % (w/v) tea and varies from 0.5 - 2.0 % (w/v) tea in water. Tea normally contains 33% soluble solids, of which EGCg is about 1 0%. Thus at the normal dose the animals receive about 0.033% (w/v) EGCg. The 1 mg/ml dose used is 0.0584% (w/v) EGCg. Three animals were sacrificed from each group at week 1 6 post inoculation and their spleens were removed for determination of histopathological changes. RESULTS AND DISCUSSION

Treatment with AZT and EGCg either alone or in combination was initiated 24 hours P.I. (post inoculation). The 24-hour waiting period was allowed to establish the infection. Mice were treated as described in Table 1 . There were 1 0 animals in each group when the experiment was started and 3 animals were sacrificed from each group at week 1 6 P.I for histopathological examination. The survival curve of C57BL/6 mice is set out in Figure 1 . From the figure, it can be seen that all of the uninfected animals were still alive when the experiment was terminated at week 33. Animals were treated as described in materials and methods. Uninf = uninfected, inf = infected, A = 0.25 mg/ml AZT, E = 1 mg/ml EGCg in drinking water.

The infected animals (Group 5) began dying at week 1 2 P.I . and 100% mortality was seen in this group by week 1 5 P.I. AZT monotherapy (Group 6) on the other hand increased survival time of the animals by up to 1 6 weeks (1 00% mortality at week 31 ). Infected animals receiving EGCg only (Group 7) started dying at week 1 2 P.I. and 100% mortality was observed in this group by week 1 6 P.I. Combination therapy (Group 8) increased survival time of the animals by up to 1 8 weeks (1 00% mortality in week 33).

From Table 1 , it can be seen that 50% of the infected animals without treatment (Group 5) reached week 1 3 while in the case of infected animals receiving EGCg only (Group 7), 50% of the animals reached week 1 5. From these results, it looked as if EGCg was slightly protective. Ten percent of the animals were still alive in the infected control group (Group 5) by week 1 6 while 30% of the animals were still alive in the infected group receiving EGCg by week 1 6 P.I (Group 7). In the case of infected animals receiving AZT only (Group 6) and the infected animals receiving combination therapy (Group 8), 50% of the animals reached week 24.

The slight improvement in the 50% survival time for the EGCg group and the 100% mortality time for the combination therapy could not be analysed statistically due to the small number of animals. There is no explanation for the early deaths in the infected animals receiving combination therapy (Group 8) at this stage.

Table 2 shows the body weight of all of the groups. To determine if AZT and EGCg either as single agents or in combination had adverse effects that would be reflected in reduced body weight of the animals, uninfected animals were treated with both these compounds and results were recorded weekly beginning at week 0 until week 21 P.I. The ANOVA procedure of the SAS software was used to compare intergroup differences. Means with the same letter are not statistically significant. There was no statistically significant difference in the body weight between the uninfected control animals (Group 1 ) and the uninfected animals receiving the three therapies (Groups 2, 3, and 4) at all time points. However, a statistically significant difference (P < 0.05) was observed between the infected (Group 5) and the uninfected control animals (Group 1 ) in week 12, 13, 14, 15 P.I with infected animals (Group 5) showing an increase in body weight. This increase was due to the viral infection and not the therapies. AZT therapy (Group 6) prevented this increase during these weeks while AZT/EGCg combination therapy (Group 8) prevented this increase in body weight only in week 13 and 14.

Table 2: Effect of AZT and/or EGCg on body weight (g) of C57BL/6 female mice infected with LP-BM5 virus week 8-1 6 pos inoculation-

All values are represented as the mean ± SD and value in brackets indicates the number of animals still alive in each treatment group Data was analysed by ANOVA. Values without a common superscipt letter are significantly different at p < 0.05.

There was no statistically significant difference in the body weight between the infected group (Group 5) and the infected group receiving EGCg monotherapy (Group 7) at all time points except at week 1 3 P.I. Combination therapy with AZT and EGCg (Group 8) limited the increase in body weight in infected animals until week 1 5 P.I. The prevention of an increase in body weight in animals receiving combination therapy (Group 8) is thought to be an effect of AZT and not EGCg since EGCg on its own did not prevent an increase in body weight associated with LP-BM5 infection. It is possible that AZT-resistant variants of the virus might have emerged at the late stage of the disease and hence AZT could no longer offer protection after ' week 22.

This study indicates that administration of AZT to LP-BM5 infected animals (Group 6) significantly prevents weight gain associated with this infection. The concentration of EGCg used was without significant effect on the body weight of infected animals (Group 7). EGCg given together with AZT (Group 8) did not produce significant improvement on the body weight on infected animals as compared to the infected animals on AZT monotherapy (Group 6). AZT and EGCg either as single agents or in combination did not show any toxicity (from the body weight data in uninfected animals) (Groups 1 , 2, 3, and 4) as there was no statistically significant difference between the vehicle only (water) control (Group 1 ) and the treatments i (Groups 2, 3, and 4) at all time points.

The work leading to the present invention is supported by prior art findings that AZT is more effective in controlling HIV in asymptomatic and AIDS related complex patients than in patients who are in the late stage of AIDS with complications due to immune dysfunction. Similar conclusions have been drawn from i studies in which similar concentrations of AZT were used in mice. Since AZT therapy does not completely inhibit retrovirus proliferation, care should be exercised in applying this therapy to HlV-infected humans. A high mortality rate of animals receiving AZT (Group 6) after week 23 might be due to the development of AZT-resistant strains of the LP-BM5 MuLV mixture at this late stage of the disease. The emergence of AZT

I resistance strains of HIV in patients treated with the drug has been reported. The infected animals receiving AZT monotherapy (Group 6) showed 1 00% mortality by week 31 P.I. while the group receiving combination therapy (Group 8) showed 100% mortality by week 33.

Similar to observations with patients on AZT, hyper pigmentation was observed. All AZT-treated mice (Group 2, 4, 6 and 8) had increased pigmentation primarily of the tail, ears, and footpads after 4 weeks of therapy. EGCg monotherapy did not cause any pigmentation on the animals. The therapeutic benefit of AZT in the treatment of both MAIDS and AIDS is the delay in disease progression, presumably by inhibition of virus spread and replication.

CONCLUSION

LP-BM5 MuLV infection of C57BL/6 mice induces a well characterized, lymphoproliferative, immunodeficiency referred to as MAIDS, which is useful for evaluation of potential antiviral agents. The MAIDS retrovirus model was used to evaluate the efficacy and toxicity of AZT and EGCg either alone or in combination. The 50% survival time for the control infected group, infected AZT treated, infected EGCg treated, and the infected group receiving AZT in combination with EGCg was 1 3, 1 5, 24, and 24 weeks respectively, while the 1 00% mortality results for the control infected group, AZT monotherapy, EGCg monotherapy, and AZT/EGCg combination therapy were 1 5, 31 , 1 6, and 33 weeks respectively. Body weight results showed that AZT monotherapy was slightly effective in preventing an increase in body weight in the infected animals while EGCg was not.

The invention shows that AZT therapy prolongs survival of animals when therapy was initiated 24 hours after virus inoculation but did not eradicate the virus. EGCg at the dose used resulted in a slight improvement in the survival of infected animals when compared with the infected animals without any treatment. Both AZT and EGCg, either as single agents or in combination, did not show any toxicity as all uninfected animals receiving treatments had normal body weights and no symptoms of adverse effects up to the termination of the experiment in week 33. TABLE 1 : Survival of the infected and uninfected animals for each type of therapy.

Claims

CLAIMS:

1 . A combination dosage for use in the treatment of a viral infection, the combination dosage comprising at least one anti-retroviral agent and at least one tea polyphenol compound.

2. A combination dosage as claimed in Claim 1 , which includes two separate formulations or compositions in which the at least one anti-retroviral agent is contained in one formulation or composition and the at least one tea polyphenol compound is contained in the other formulation or composition.

3. A combination dosage as claimed in Claim 1 , in which the at least one anti-retroviral agent and the at least one tea polyphenol compound are contained in a single formulation or composition.

4. A combination dosage as claimed in any one of Claims 1 to 3 inclusive, in which the anti-retroviral agent is 3'-azido-3'-deoxythymidine.

5. A combination dosage as claimed in any one of the preceding claims, in

I which the at least one tea polyphenol compound is selected from the group consisting of tea catechins, theaflavins, thearubigins and combinations thereof.

6. A combination dosage as claimed in Claim 5, in which the at least one tea polyphenol compound is selected from epigallocatechin gallate (EGCg), epicatechin gallate (ECg), epigallocatechin (EGC), gallochatecin (GC), epicatechin (EC), epicatechin gallate (ECg), catechin (C), catechin gallate (Cg), theaflavin, theaflavin digallate, theaflavin monogallate, caffeine, theanine and combinations of any two or more thereof.

7. A combination dosage as claimed in any one of Claims 1 to 4 inclusive, in which the at least one tea polyphenol compound is obtained by extracting the plant

) Camellia sinensis.

8. A combination dosage as claimed in any one of claims 4 to 7 inclusive, which contains between about 20 and 300 mg of 3'-azido-3'-deoxythymidine

9. A combination dosage as claimed in claim 8, which contains between about 80 and 1 50 mg of 3'-azido-3'-deoxythymidine.

1 0. A combination dosage as claimed in any one of the preceding claims, which contains between about 4 and 300 mg of the at least one tea polyphenol compound.

1 1 . A combination dosage as claimed in Claim 10, which contains between about 10 and 100 mg of the at least one tea polyphenol compound.

I 1 2. A dosage kit for use in the treatment of a viral infection, the dosage kit comprising at least one anti-retroviral agent and at least one tea polyphenol compound.

1 3. A dosage kit as claimed in Claim 1 2, which includes separate dosage forms respectively containing the at least one anti-retroviral agent and the at least one tea polyphenol compound.

14. A dosage kit as claimed in Claim 1 2, which includes a single dosage form which contains the at least one anti-retroviral agent and the at least one tea polyphenol compound.

1 5. A dosage kit as claimed in any one of Claims 1 2 to 14 inclusive, in which the dosage forms are selected from solid dosage forms and liquid dosage forms.

1 6. A dosage kit as claimed in any one of Claims 1 2 to 1 5 inclusive, in which the anti-retroviral agent is 3'-azido-3'-deoxythymidine.

1 7. A dosage kit as claimed in any one of Claims 1 2 to 1 6 inclusive, in which the at least one tea polyphenol compound is selected from the group consisting of tea catechins, theaflavins, thearubigins and combinations thereof.

1 8. A dosage kit as claimed in Claim 1 7, in which the at least one tea polyphenol compound is selected from epigallocatechin gallate (EGCg), epicatechin gallate (ECg), epigallocatechin (EGC), gallochatecin (GC), epicatechin (EC), epicatechin gallate (ECg), catechin (C), catechin gallate (Cg), theaflavin, theaflavin digallate, theaflavin monogallate, caffeine, theanine and combinations of any two or more thereof.

1 9. A dosage kit as claimed in any one of Claims 1 2 to 1 6 inclusive, in which the at least one tea polyphenol compound is obtained by extracting the plant Camellia i sinensis.

20. A substance or composition for use in the treatment of a viral infection, the substance or composition comprising at least one anti-retroviral agent and at least one tea polyphenol compound.

21 . Use of a combination of substances or compositions in the manufacture of a dosage form for the treatment of a viral infection, the substances or compositions comprising at least one anti-retroviral agent and at least one tea polyphenol compound.

22. Use as claimed in Claim 21 , in which the dosage form is a single composition which contains the at least one tea polyphenol compound and the at least one anti-retroviral agent.

i 23. Use as claimed in Claim 21 , in which the dosage form comprises separate compositions which respectively contain the at least one tea polyphenol compound and the at least one anti-retroviral agent.

24. Use as claimed in any one of Claims 21 to 23 inclusive, in which the anti-retroviral agent is 3'-azido-3'-deoxythymidine.

25. Use as claimed in any one of Claims 21 to 24 inclusive, in which the at least one tea polyphenol compound is selected from the group consisting of tea catechins, theaflavins, thearubigins and combinations thereof.

26. Use as claimed in Claim 25, in which the at least one tea polyphenol is selected from epigallocatechin gallate (EGCg), epicatechin gallate (ECg), epigallocatechin (EGC), gallochatecin (GC), epicatechin (EC), epicatechin gallate (ECg), catechin (C), catechin gallate (Cg), theaflavin, theaflavin digallate, theaflavin monogallate, caffeine, theanine and combinations of any two or more thereof.

27. Use as claimed in any one of Claims 21 to 24 inclusive, in which the at > least one tea polyphenol compound is obtained by extracting the plant Camellia sinensis.

28. A method of treating a viral infection, the method including administering to a person or animal in need of treatment, at least one anti-retroviral agent and at least one tea polyphenol compound.

i 29. A method as claimed in Claim 28, in which the at least one anti-retroviral agent and at least one tea polyphenol compound are contained in a single formulation or composition.

30. A method as claimed in Claim 28, in which the at least one anti-retroviral agent and at least one tea polyphenol compound are contained in separate

» formulations or compositions.

31 . A method as claimed in any one of Claims 28 to 30 inclusive, in which the anti-retroviral agent is 3'-azido-3'-deoxythymidine.

32. A method as claimed in any one of Claims 28 to 31 inclusive, in which the at least one tea polyphenol compounds is selected from the group consisting of tea i catechins, theaflavins, thearubigins and combinations thereof.

33. A method as claimed in Claim 32, in which the at least one tea polyphenol compound is selected from epigallocatechin gallate (EGCg), epicatechin gallate (ECg), epigallocatechin (EGC), gallochatecin (GC), epicatechin (EC), epicatechin gallate (ECg), catechin (C), catechin gallate (Cg), theaflavin, theaflavin digallate, i theaflavin monogallate, caffeine, theanine and combinations of any two or more thereof.

34. A method as claimed in Claim 32, in which the at least one tea polyphenol compound is obtained by extracting the plant Camellia sinensis.

35. A method as claimed in any one of Claims 28 to 35 inclusive, in which I the anti-retroviral agent is administered in an amount of between about 1 and

1 70mg/kg body weight/day.

36. A method as claimed in Claim 35, in which the anti-retroviral agent is administered in an amount of between about 5 and 51 mg/kg body weight/day.

37. A method as claimed in any one of Claims 28 to 36 inclusive, in which i the tea polyphenol compound is administered in an amount of between about 1 and

2000 mg/kg body weight per day.

38. A method as claimed in Claim 37, in which the tea polyphenol compound is administered in an amount of between about 70 and 600 mg/kg body weight per day.

) 39. In a method of treating a viral infection in a patient which comprises administering to a patient an effective amount of at least one anti-retroviral agent, there is provided the improvement which comprises also administering to the patient an effective amount of at least one tea polyphenol compound.

40. A combination dosage as claimed in Claim 1 , substantially as herein i described and illustrated.

41 . A dosage kit as claimed in Claim 12, substantially as herein described and illustrated.

42. A substance or composition as claimed in Claim 20, substantially as herein described and illustrated.

i 43. Use as claimed in Claim 21 , substantially as herein described and illustrated.

44. A method as claimed in Claim 28, substantially as herein described and illustrated.

45. A new combination dosage, a new dosage kit, a new use, a new method ) or a new improvement substantially as herein described.