Anti-HIV activities of extracts from Pu-erh tea

AIM: To evaluate the anti-HIV activities of extracts from two commonly forms of Pu-erh tea (fermented), green tea-like (unfermented). METHODS: The cytotoxicities of extracts on C8166, MT4 and PBMC were assessed by MTT and the anti-HIV activities of extracts were evaluated by syncytium reduction and p24 antigen assay. RESULTS: All extracts had low cytotoxicities with the CC50 from 120.63 to 524.95 gmL-1. All extracts can inhibit HIV-induced cytopathic effects, with EC50 various from 11.13 to 67.49 gmL-1. The WEPT's were better than EEPTs, moreover the FPT's water extracts were better than the GTLPT's especially YYP-31 with SI value 42.40. YYP-31 also inhibited HIV-1RF and HIV-2CBL-20 infection with EC50 of 30.82 and 39.79 gmL-1, respectively. YYP-31 reduced p24 antigen expression in HIV-1IIIB acute infected C8166 and in HIV-1KM018 infected PBMC with EC50 values of 14.95 and 74.63 gmL-1, respectively. YYP-31 blocked the fusion between normal C8166 cells and HIV-1 chronically infected H9 cells with EC50 values of 234.27 gmL-1. It exhibits markedly synergistic anti-HIV activity in combination with AZT but can't inhibit activities of reverse transcriptase. CONCLUSION: Pu-erh tea extracts exhibit highly efficient anti-HIV-1 activity and can be considered to be used to as a complementary therapy or a health product to HIV patients.