Preventive effect of taraxasteryl acetate from Inula britannica subsp. japonica on experimental hepatitis in vivo.

The survival rate for acute hepatic failure induced by Propionibacterium acnes and lipopolysaccharide (LPS) was increased when a hot water extract from the flowers of Inula britannica L. subsp. japonica Kitam. was injected into the experimental hepatitis mice, and anti-hepatitis substances could be extracted with CHCl3. The CHCl3 extract from I.britannica was fractionated and anti-hepatitis fractions IB-3-2 and IB-3-3 were obtained. IB-3-3 had the most potent anti-hepatitis activity among the fractions but further purification of the active compound was not achieved because of the low yield. IB-3-2 contained only one substance which was identified to be taraxasteryl acetate by 1H- and 13C-NMR and MS. Taraxasteryl acetate showed potent preventive activity against acute hepatic failure induced by P.acnes and LPS in a dose-dependent manner, however deacetylation and modification of the olefinic bonds significantly decreased the anti-hepatitis activity of taraxasteryl acetate. Taraxasteryl acetate also inhibited the increment of plasma transaminase on acute hepatic failure induced by carbon tetrachloride (CCl4) or D-galactosamine. From a histological study it appeared that degeneration and necrosis, which were observed in the liver from CCl4 mice, were not found in the liver cells from taraxasteryl acetate treated mice. These results indicates that taraxasteryl acetate shows preventive effects on experimental hepatitis caused by either immunologically induced injuries or hepatotoxic chemicals.