Assessment of anti-hepatitis B virus activity of endemic medicinal plants from Socotra Island

Hepatitis B virus (HBV) is a leading cause of liver disease and a possible worldwide source of severe morbidity and mortality. The current standard therapy using interferons or antiviral agents is not successful in all cases and is associated with severe side effects. Consequently, the development of new medicines for the treatment of HBV is still relevant. This experimental study was therefore performed to assess the anti-hepatitis B virus (HBV) potential of 10 endemic medicinal plants from Socotra Island which represents a distinctive region of Yemen. Socotra Island is renowned for its biodiversity with significant flora with globally important plants. The methanolic extracts of the selected plants were first assessed for cytotoxicity on HepG2.2.15 cells and cytotoxicity concentration (CC50) values were resolved. The methanolic extracts of the plants were additionally examined on HepG2.2.15 cells for anti-HBV potential by examining the inhibition of HBsAg and HBeAg production in the culture supernatants, and calculating their half-maximum inhibitory concentration (IC50) and therapeutic index (TI) values. Out of ten plants only five plants exhibit inhibition of HBsAg production in a dose and time dependent manner. These five plants are Acacia pennivenia, Boswellia discorea, B. socotrana, Hypoestes pubescens and Dracaena cinnabari with IC50 values of 21.15, 24.51, 118.94, 17.65, 20.93 μg/mL, respectively. Moreover, the presence of terpenoids, tannins, alkaloids and flavonoids that could contribute to antiviral efficacy was validated with a qualitative phytochemical study of active extracts. Key words: Antiviral, Hepatitis B, medicinal plants; Socotra, Yemen.