Antiviral Activity of Selected Indian Medicinal Herbs Against Hepatitis E Virus (Hev) in the Established Porcine Cell Model

Abstract

Abstract:Background: It is known that hepatitis E virus (HEV) is zoonotically transmitted to humans and while other forms of hepatitis have been in focus for drug and vaccine development, HEV related mortality in case of pregnant women can reach upto 20%. Methods: HEV proteins, were successfully extracted from 22 pig stool samples and the presence of HEV capsid antigen encoded by the open reading frame 2 (ORF2) was confirmed using dot blot and western blotting in 4 samples. HEV samples were inoculated in pig epithelial cells (CLAB) and pig macrophage (POM2) to develop an in vitro model for observing the cytopathic effects (CPE). The HEV infected cell cultures were subjected to water: methanol (95:5) extracts from Kaempfaria galanga (Galangal), Mimosa pudica (Touch me not), Coleus aromaticus (Doddapatre)and Paederia foetida (Stinkvine).Results:We showed that incubation of 56 μg/mL HEV samples for 3 hours induced characteristic growth patterns in cells until 4 passages. We also found that extracts of K. galanga significantly (p<0.001) increased cell viability in CLAB cells while other extracts showed cytotoxic effects. In the preventive study (treatments of cells with extracts followed by infection of cells with viral proteins), both 10 -2 and 10 -3 dilutions of K. galanga extracts significantly (p<0.001) prevented a decrease in cell viability of CLAB cells after HEV infection. The 10 -2 dilution of C. aromaticus (p<0.01) and 10 -3 dilution of K. galanga was the only effective (p<0.001) extract in case of HEV infected POM2 cells. Conclusion: A new in vitro cell culture model based on CLAB and POM2 cells has been developed to study HEV.We are also the first to report the activity of these medicinal extracts against HEV in a cell culture model. Extracts of K. galanga and P. foetida showed a promising anti-viral activity and the potential to be used as a natural therapy against HEV.