Objective: To screen and evaluate the anti-HIV activities of extracts from Chinese medicinal formula Liangcha.
Methods: The anti-HIV-1 activities of extracts from Chinese medicinal formula Liangcha were evaluated by cytotoxicity assay,syncytium reduction assay, protection for HIV-1 induced lytic assay, and ELISA assay for HIV-1 p24 antigen expression. The primary mechanisms were investigated by fusion inhibition assay, inhibition of viral replication in HIV-1 chronically infected H9 cell and inhibition assay of HIV-1 RT activity.
Results: The extracts from Chinese medicinal formula Liangcha exhibited potent and broad-spectrum anti-HIV-1 activity on different HIV-1 strains with EC50 range 12.74 -116.87 microg/mL, but weakly inhibited HIV-2 replication. Meantime, it was not significantly cytotoxic in several T lymphocytes cell lines with CC50 range 564.79 - 1699.22 microg/mL. The activity of recombinant HIV-1 reverse transcriptase was inhibited by extracts from Chinese medicinal formula Liangcha, inhibition rate more than 50% at the concentration of 5.3 microg/mL. It also weakly inhibited the cell-to-cell fusion in co-culture with EC50 of 101.94 microg/mL.
Conclusion: The extracts from Chinese medicinal formula Liangcha exhibited potent and broad-spectrum anti-HIV-1 activity on different HIV-1 strains in vitro. Its anti-HIV-1 mechanism might be inhibiting HIV-1 reverse transcriptase and cell entry.