Evaluation of the fractions from Caspian cobra venom on apoptosis of infected BHK-21 by Rabies Virus

Rabies is zoonotic acute encephalitis that continuously kills thousands of people annually with almost 100 percent fatality. In the present study, apoptosis was investigated in BHK- 21 cell lines infected by rabies virus. Apoptotic cells are identified by fragmented and dense chromatin masses and evaluated by microscopic and statistical methods. In vitro apoptosis was time and dose-dependent in 24 to 72 hours of incubation in BHK-21cell lines; however, a marked reduction in the number of apoptotic cells was observed, especially at the lowest concentrations of F4 and F5 fractions, obtained by FPLC of crude Naja naja oxiana venom. The number of infected apoptotic cells in the presence of different concentrations of two fractions F4 (40, 30 and 20μg/ml) and F5 (40, 25 and 15μg/ml) of Caspian cobra venom are obtained by Hoechst staining. According to the obtained results, by decreasing the concentrations of F4 and F5 fractions, the apoptotic indices were decreased in each incubation time. The F5 fraction in comparison with F4 at the same incubation times (24, 48 and 72h) showed more effective on apoptosis of infected cells. The highest percentages (66.57% and 65.43%) of apoptotic cells which were recorded after 48 and 72 hours belong to 40μg/ml of F5 fraction respectively. Our observations have shown that the use of a specific fraction (F5) of cobra venom, in an efficient concentration and time can cause apoptosis of rabiesinfected cells, so it can be hoped that this toxic fraction will be a candidate in treatment of Rabies virus proliferation.