Inhibition of hepatitis B surface antigen expression by medicinal plant extracts

Abstract

The purpose of this study was to investigate antiviral activity of thirteen medicinal plants by studying the inhibition of hepatitis B surface antigen (HBsAg) secretion from PLC/PRF/5 cells. The result showed that 12 ethanol plant extracts could inhibit HBsAg secretion from PLC/PRF/5 cells and all of them showed the selectivity index [SI = 50%cytotoxic concentration (CC50)/50% inhibition concentration (IC50)] more than one . Ethanol extracts of Derris scandens, Rhinacanthus nasutus, and Santalum album were then selected to be partitioned with hexane, chloroform, ethyl acetate, and butanol, respectively. These fractions were further investigated for anti-HBsAg activity and cytotoxicity. The butanol fraction of D. scandens, hexane fraction of R. nasutus, and hexane fraction of S album exhibited the lowest IC50 in each plant. Furthermore, the butanol fraction of D. scandens and hexane fraction of R. nasutus which showed low IC50 were selected for partial purification by column chromatography and tested for anti­HBsAg activity. The fraction of R. nasutus which exhibited the highest activity had IC50 of 3.13 µg/ml, CC50 of 14.11 µg/ml, and Sl of 4.51. The fraction of D. scandens which exhibited the highest activity had IC50 of 48.36 µg/ml, CC50 of 90.99 µg/ml, and Sl of 1.88. In addition, thin layer chromatography (TLC) of these fractions were also performed. The results showed more than one substances in each fraction. R. nasutus and D. scandens were interested to perform more investigation for anti-HBsAg pure compounds.