Baicalein appears to be a potent inhibitor of reverse transcriptase. The first key sentence below seems to give some cause for caution.

Baicalein is in the herb skullcap (or scullcap).

Skullcap can be obtained in Australia by visiting a Naturopath.

It is produced by the company Medi Herb. I do not know what dose you need to take to be effective, but it's use for other purposes is 2-3 drops in water twice a day.

It's also very cheap. I got a bottle for less than $8.00 Australian.

The Chinese medicines that contain Baicalein may also be available. I haven't checked them yet.

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Baicalin might selectively induce apoptosis of CEM-HIV cells which have a high virus-releasing capacity, and stimulate proliferation of CEM-HIV which have a relatively lower capacity of HIV-production.

Four flavonoids (i.e., baicalein, quercetin, quercetagetin, and myricetin), known to be inhibitors of HIV-reverse transcriptase, have been shown to be more or less

inhibitory to the activities of various cellular DNA and RNA polymerases.

Four flavonoids, 5,6,7-trihydroxyflavone (baicalein), 3,3',4',5,7-pentahydroxyflavone (quercetin), 3,3',4',5,6,7-hexahydroxyflavone (quercetagetin) and

3,3',4',5,5',7-hexahydroxyflavone (myricetin), were found to be potent inhibitors of reverse transcriptases from Rauscher murine leukemia virus (RLV) and human

immunodeficiency virus (HIV).

5,6,7-Trihydroxyflavone (baicalein) is a potent inhibitor of the activities of reverse transcriptases from murine leukemia viruses (MLV) (Rauscher and Moloney

strains) and human immunodeficiency virus (HIV).

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Jpn J Med Sci Biol 1995 Apr;48(2):79-87

Apoptosis of HIV-infected cells following treatment with Sho-Saiko-to and its components.

Wu X, Akatsu H, Okada H

Department of Molecular Biology, Nagoya City University School of Medicine.

Baicalein and baicalin are components of Sho-saiko-to (SST), a Chinese medical drug which is claimed to be therapeutically effective in treating HIV-infected

patients. Although 20 micrograms/ml of baicalin was not cytotoxic to CEM cells, a cultured T cell line, it proved to be cytotoxic to HIV-infected CEM cells

(CEM-HIV) with a higher HIV-releasing capacity and DNA fragmentation was detected within 24 hr of incubation. However, after incubation of CEM-HIV with

a lower dose of baicalin (0.1, 0.3 and 2 micrograms/ml) for 24 and 48 hr, the viable cell number increased by about 25% and the p24 release into the medium

was 25% lower than that of the control. After further incubation in the presence of the agent for 6 and 9 days, only cells with a lower HIV-releasing capacity

survived. Baicalin might selectively induce apoptosis of CEM-HIV cells which have a high virus-releasing capacity, and stimulate proliferation of CEM-HIV which

have a relatively lower capacity of HIV-production.

PMID: 7474502, UI: 96022735

Key Sentence:

Baicalin might selectively induce apoptosis of CEM-HIV cells which have a high virus-releasing capacity, and stimulate proliferation of CEM-HIV which

have a relatively lower capacity of HIV-production.

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J Biochem (Tokyo) 1990 Oct;108(4):609-13

Mechanisms of inhibition of various cellular DNA and RNA polymerases by several flavonoids.

Ono K, Nakane H

Laboratory of Viral Oncology, Aichi Cancer Center Research Institute.

Four flavonoids (i.e., baicalein, quercetin, quercetagetin, and myricetin), known to be inhibitors of HIV-reverse transcriptase, have been shown to be more or less

inhibitory to the activities of various cellular DNA and RNA polymerases. The degree of the inhibition varied depending on the combination of the flavonoid and

the enzyme species: baicalein was moderately inhibitory to DNA polymerase gamma and E. coli DNA polymerase I; quercetin was strongly inhibitory to DNA

polymerase beta and E. coli RNA polymerase and moderately inhibitory to DNA polymerase I; quercetagetin was a potent inhibitor for all of DNA polymerases

alpha, beta, gamma, and I and RNA polymerase; myricetin was a strong inhibitor of DNA polymerases alpha and I and RNA polymerase. However, terminal

deoxynucleotidyltransferase was virtually insensitive to inhibition by these flavonoids. The inhibition by the flavonoids was due to competition with the

template.primer in the case of the DNA polymerases, whereas the inhibition was due to competition with the triphosphate substrate (GTP) in the case of RNA

polymerase. The Ki values of these flavonoid inhibitors for DNA and RNA polymerases was determined.

PMID: 2292590, UI: 91154169

Key Sentence:

Four flavonoids (i.e., baicalein, quercetin, quercetagetin, and myricetin), known to be inhibitors of HIV-reverse transcriptase, have been shown to be more or less

inhibitory to the activities of various cellular DNA and RNA polymerases.

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Antiviral Res 1990 Oct-Nov;14(4-5):279-86

Inhibition of HIV replication in lymphocyte cultures of virus-positive subjects in the presence

of sho-saiko-to, an oriental plant extract.

Buimovici-Klein E, Mohan V, Lange M, Fenamore E, Inada Y, Cooper LZ

Department of Pediatrics, St. Luke's Roosevelt Hospital Center, New York, NY 10019.

An oriental remedy, Sho-saiko-to (SST) consisting of a mixture of aqueous extracts from seven different plants and whose most active component is the

chemically defined compound baicalein was tested for its ability to inhibit the production of the human immunodeficiency virus (HIV). The testing was done with

cultures of human lymphocytes obtained from HIV-positive asymptomatic subjects and patients with ARC or AIDS. The replication of the virus was monitored

by quantitative assay of the reverse transcriptase (RT) activity and of the synthesis of antigen p24. The lymphocyte cultures (LC) were maintained in the absence

and in the presence of 25, 50 or 100 micrograms/ml of SST, and monitored for up to 5 weeks. The results showed that in LC from asymptomatic subjects RT

activity and synthesis of p24 was completely inhibited by low concentrations of SST. High concentrations of SST inhibited virus replication in 80% of LC from

ARC patients, but were completely ineffective in LC from AIDS patients. It was observed that the RT activity was more sensitive to inhibition by SST than the

synthesis of p24, and that the antiviral effect was dependent on the virus load of the LC.

PMID: 1708225, UI: 91207055

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Eur J Biochem 1990 Jul 5;190(3):469-76

Differential inhibitory effects of various flavonoids on the activities of reverse transcriptase and

cellular DNA and RNA polymerases.

Ono K, Nakane H, Fukushima M, Chermann JC, Barre-Sinoussi F

Laboratory of Viral Oncology, Aichi Cancer Center Research Institute, Nagoya, Japan.

Four flavonoids, 5,6,7-trihydroxyflavone (baicalein), 3,3',4',5,7-pentahydroxyflavone (quercetin), 3,3',4',5,6,7-hexahydroxyflavone (quercetagetin) and

3,3',4',5,5',7-hexahydroxyflavone (myricetin), were found to be potent inhibitors of reverse transcriptases from Rauscher murine leukemia virus (RLV) and human

immunodeficiency virus (HIV). Under the reaction conditions employed, any one of these flavonoids almost completely inhibited the activity of RLV reverse

transcriptase at a concentration of 1 microgram/ml. HIV reverse transcriptase was inhibited by 100%, 100%, 90% and 70% in the presence of 2 micrograms/ml

quercetin, myricetin, quercetagetin and baicalein, respectively. The mode of inhibition of these flavonoids was competitive (RLV reverse transcriptase) or partially

competitive (HIV reverse transcriptase) with respect to the template.primer complex, (rA)n.(dT), and noncompetitive with respect to the triphosphate substrate,

dTTP. The Ki values for RLV reverse transcriptase were found to be 0.37 microM and 0.08 microM for baicalein and quercetin, respectively and those for HIV

reverse transcriptase were 2.52 microM, 0.52 microM, 0.46 microM and 0.08 microM for baicalein, quercetin, quercetagetin and myricetin, respectively.

Comparative studies with other flavonoids (hydroxyflavones, dihydroxyflavones and polyhydroxyflavones and flavanones) carried out to clarify the

structure/activity relationships, revealed that the presence of both the unsaturated double bond between positions 2 and 3 of the flavonoid pyrone ring, and the

three hydroxyl groups introduced on positions 5, 6 and 7, (i.e. baicalein) were a prerequisite for the inhibition of reverse transcriptase activity. Removal of the

6-hydroxyl group of baicalein required the introduction of three additional hydroxyl groups at positions 3, 3' and 4' (quercetin), to afford a compound still capable

of inhibiting the reverse transcriptase activity. Quercetagetin which contains the structures of both baicalein and quercetin, and myricetin which has the structure of

quercetin with an additional hydroxyl group on the 5' position also proved strong inhibitors of reverse transcriptase activity. The inhibition by baicalein of reverse

transcriptase is highly specific, whereas quercetin and quercetagetin were also strong inhibitors of DNA polymerase beta and DNA polymerase I, respectively.

Myricetin was also a potent inhibitor of both DNA polymerase alpha and DNA polymerase I.

PMID: 1695572, UI: 90322990

Key Sentence:

Four flavonoids, 5,6,7-trihydroxyflavone (baicalein), 3,3',4',5,7-pentahydroxyflavone (quercetin), 3,3',4',5,6,7-hexahydroxyflavone (quercetagetin) and

3,3',4',5,5',7-hexahydroxyflavone (myricetin), were found to be potent inhibitors of reverse transcriptases from Rauscher murine leukemia virus (RLV) and human

immunodeficiency virus (HIV).

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Biochem Biophys Res Commun 1989 May 15;160(3):982-7

Inhibition of reverse transcriptase activity by a flavonoid compound, 5,6,7-trihydroxyflavone.

Ono K, Nakane H, Fukushima M, Chermann JC, Barre-Sinoussi F

Laboratory of Viral Oncology, Aichi Cancer Center Research Institute, Nagoya, Japan.

5,6,7-Trihydroxyflavone (baicalein) is a potent inhibitor of the activities of reverse transcriptases from murine leukemia viruses (MLV) (Rauscher and Moloney

strains) and human immunodeficiency virus (HIV). Under the reaction conditions specified for each of the MLV- and HIV-reverse transcriptases, both enzyme

activities were inhibited by more than 90% in the presence of 2 micrograms/ml baicalein. The mode of the inhibition by baicalein was competitive with respect to

the template.primer, (rA)n.(dT)12-18, and noncompetitive to dTTP substrate. Ki value of baicalein for the MLV-reverse transcriptase was determined to be 0.37

microM.

PMID: 2471525, UI: 89273615

Key Sentence:

5,6,7-Trihydroxyflavone (baicalein) is a potent inhibitor of the activities of reverse transcriptases from murine leukemia viruses (MLV) (Rauscher and Moloney

strains) and human immunodeficiency virus (HIV).