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Fitoterapia. 2012 Mar;83(2):348-55. doi: 10.1016/j.fitote.2011.11.016. Epub 2011 Dec 3.

A natural theaflavins preparation inhibits HIV-1 infection by targeting the entry step: potential applications for preventing HIV-1 infection.

Author information

1
School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China.

Abstract

Theaflavins are the major components of tea polyphenols in brewed black tea. We previously reported that theaflavin derivatives, such as TF3, inhibited HIV-1 entry by targeting gp41. However, it is difficult to purify the individual theaflavins and the purified compounds are highly unstable. To develop theaflavins as affordable anti-HIV-1 microbide for preventing HIV sexual transmission, we intended to use an economic natural preparation containing 90% of theaflavins (TFmix). Its antiviral activity against HIV-1 strains was evaluated in vitro using p24 production and luciferase assays. The mechanism by which TFmix inhibits HIV-1 infection was investigated using time-of-addition, cell-cell fusion and biophysical assays. The data suggested TFmix exhibited potent anti-HIV-1 activity on lab-adapted and primary HIV-1 strains with IC(50) less than 1.20 μM. It also effectively inhibited infection by T-20 resistant HIV-1 strains. The mechanism studies suggest that TFmix mainly inhibit the HIV-1 entry by targeting gp41 since it is effective in inhibiting gp41 six-helix bundle (6-HB) formation and HIV-1 envelope protein-mediated cell-cell fusion. TFmix could also inhibit HIV-1 reverse transcriptase (RT) activity, but the IC(50) is about 8-fold higher than that for inhibiting gp41 6-HB formation, suggesting RT is not a major target for TFmix. In conclusion, TFmix is an economic natural product preparation containing high content of theaflavins with potent anti-HIV-1 activity by targeting the viral entry step through the disruption of gp41 6-HB core structure. It has a potential to be developed as a safe and affordable topical microbicide for preventing sexual transmission of HIV.

PMID:
22155187
DOI:
10.1016/j.fitote.2011.11.016
[Indexed for MEDLINE]

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