Potent Anti-HIV Activities and Mechanisms of Action of a Pine Cone Extract from Pinus yunnanensis

Abstract

The anti-HIV activities of a pine cone extract (YNS-PY-F) from Pinus yunnanensis have been evaluated, and its mechanisms of action were also explored. The pine cone extract, YNS-PY-F, potently inhibited HIV-1IIIB, HIV-1RF, HIV-1A17, HIV-1AO18 and HIV-2ROD and induced cytopathic effect in C8166 cells with EC50 values of 0.96 μg/mL, 1.53 μg/mL, 0.88 μg/mL, 7.20 μg/mL and 6.17 μg/mL, respectively. The quantification of a p24 production assay showed that YNS-PY-F significantly inhibited the acute replication of HIV-1IIIB, HIV-1RF, HIV-1A17 and HIV-1AO18 in C8166 cells. An MTT assay showed that YNS-PY-F also significantly inhibited the HIV-1IIIB induced cytolysis in MT-4 cells with an EC50 value of 2.22 μg/mL. The mechanism assays showed that YNS-PY-F had potent inhibitory effects on the fusion between infected cells and uninfected cells, and the activity of HIV-1 reverse transcriptase, with EC50 values of 7.60 μg/mL and 4.60 μg/mL, respectively. Overall, these data suggest that the pine cone extract from Pinus yunnanensis has potent inhibitory activities against HIV-1IIIB, HIV-1RF, RT inhibitor-resistant strains HIV-1A17 and HIV-1AO18, and HIV-2ROD, and its anti-HIV mechanisms include inhibition of HIV entry and inhibition of reverse transcriptase activity.