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.
由
丙酸杆菌(Propionibacterium acnes)和脂
多糖(LPS)诱导的急性肝衰竭的存活率在注射了日本千层花(Inula britannica L. subsp. japonica Kitam.)花朵热
水提取物的实验性肝炎小鼠中有所提高,且可以用
氯仿(
CHCl3)提取抗肝炎物质。来自I. britannica的
氯仿提取物经过分级分离,获得了抗肝炎分 fraction IB-3-2 和 IB-3-3。IB-3-3在各分级中表现出最强的抗肝炎活性,但由于产量低,未能进一步纯化活性成分。IB-3-2仅包含一种物质,通过1H-和13C-NMR以及质谱(MS)鉴定为塔拉克萨斯特酯(taraxasteryl acetate)。塔拉克萨斯特酯对由P. acnes和LPS诱导的急性肝衰竭表现出明显的剂量依赖性预防活性,然而去乙酰化和烯烃键的修饰显著降低了塔拉克萨斯特酯的抗肝炎活性。塔拉克萨斯特酯还抑制了由
四氯化碳(
CCl4)或
D-半乳糖胺诱导的急性肝衰竭中血浆转
氨酶的升高。通过组织学研究发现,在 小鼠的肝脏中观察到的变性和坏死现象在接受塔拉克萨斯特酯处理的小鼠肝细胞中没有发现。这些结果表明,塔拉克萨斯特酯对由免疫诱导的损伤或肝毒
化学物质引起的实验性肝炎具有预防作用。