Plant-derived antiviral drugs as novel hepatitis B virus inhibitors: Cell culture and molecular docking study

Parvez, Mohammad K.; Tabish Rehman, Md.; Alam, Perwez; Al-Dosari, Mohammed S.; Alqasoumi, Saleh I.; Alajmi, Mohammed F.

The HBV secretory protein 'e' antigen (HBeAg) is a processed product of the 'pre-Core' gene that is co-translated with 'Core' by a bicistronic subgenomic-RNA. Therefore, in natural infection, seropositivity of HBeAg is a hallmark of active viral DNA replication (Shafritz and Lieberman, 1984; Beck and Nassal, 2007) . Notably, this is analogous to HIV 'p24 0 antigen where ELISA is a valid tool to monitor retroviral RNA replication (Cunningham et al., 1993) . We therefore, further evaluated the antiviral compounds on their inhibitory effect on HBeAg production for five days (Fig. 3) . Notably, prolonged treatment beyond day 5 did not show any significant effect and further continuation resulted in cell overgrowth and death (data not shown). The estimated antiviral activities of the compounds on day 5 post-treatment were: quercetin (73%) > baccatin III (71%) > psoralen (67%) > embelin (65.5%) > menisdaurin (64%) > azadirachtin (62%) > lupeol (52.5%) > rutin (47.5%) > bsitosterol (43%) > hesperidin (41%). Of these, while six compounds (quercitin, psoralen, baccatin III, menisdaurin, embelin and azadirachtin) showed promising efficacies, four (lupeol, rutin, bsitosterol and hesperidin) had moderate anti-HBV activities.