Experimental Study On Anti-HIV-1 Activity Of YBF

Aquired Immune Deficiency Syndrome(AIDS), which is a collection of symptoms and infections resulting from the specific damage to the immune system in human, is caused by human immunodeficiency virus(HIV). AIDS patients often have an increased risk of developing opportunistic infections and tumors. HIV-1 is the source of 95% HIV infections throughout the world. Since AIDS was first reported in the United States in 1981, there have been more than 2.5 million people died of AIDS throughout the world.So far, the Food and Drug Administration(FDA) has approved 29(including fixed-dose combinations) drugs for treating HIV infection, which can be divided into 5 categories based on their mechanisms of action: nucleoside/nucleotide reverse transcriptase inhibitors, non nucleoside reverse transcriptase inhibitors, integrase inhibitors, protease inhibitors, and entry/fusion inhibitors. At present, the Highly Active Anti-Retroviral Therapy(HAART) is the major treatment method in clinical practice, which can reduce the viral load in patients body and prolong the life of patient. But, because antiviral drugs were obtained by chemical synthesis, they have much limitation such as serious side effects, high price, drug-resistance, and can not completely eliminate HIV in human body. So, HAART is restricted in application at a certain extent. On the other side, natural products have different structures, various bioactivities, less side effects, and a rich source. Thus, it plays more and more important roles in developing new drugs and lead compounds.In this project, we began with the different crude extracts of YBF, and examine their anti-HIV-1 activities. The effective crude extract was isolated and purified by TLC(Thin-Layer Chromatography) and column chromatography guiding by bioactivity. CPE and p24 antigen assay were adopted to examine the anti-HIV-1 activity of drugs. In the study of mechanism of action, we examine the binding of drugs with target proteins by BIA technique. In this project, cell strain is MT4 cell and virus strain is HIV-1ⅢB. Results show that the 30% EtOH extract from YBF exhibited remarkable anti-HIV-1 activity compared with other different concentration EtOH extracts. The 30% EtOH extract was further isolated and purified, and we got the two last effective parts: A3O2 and B6. Inhibitory rate of A3O2 at 125μg/mL is 74.8815%, and inhibitory rate of B6 at 125μg/mL is 73.7115%. The TI of A3O2 and B6 are respectively 41.22 and 43.59. Both of their TI are more than 10, so A3O2 and B6 can be developed as anti-HIV-1 drugs. The binding of A3O2 at 20μg/mL with Vif is 69.6RU, and the binding of B6 at 20μg/mL with Vif is 59.7RU. The BIA results indicate that Vif may be one of the action targets of A3O2 and B6.In this project, bioactivity-directed fractionation and isolation were adopted, by which the effective parts of YBF on anti-HIV-1 activity were sought pertinently. We illuminate the substance basis of YBF on anti-HIV-1 activity, and provide foundation for further reseach and development of YBF on anti-HIV-1 activity.