积雪草甙对乳腺癌MCF-7细胞凋亡及VEGF、bFGF蛋白表达水平的影响

目的:探讨积雪草甙对乳腺癌MCF-7细胞凋亡及VEGF、bFGF蛋白表达水平的影响。方法:选取人乳腺癌细胞MCF-7细胞系进行体外培养后,根据是否进行积雪草甙干预而分为两组,应用积雪草苷进行干预后,HE染色后用光学显微镜法观察细胞形态学变化,干预后的24h、48h以及72h时,应用TUNEL技术对对细胞凋亡情况进行检测,同时应用免疫荧光法检测血管内皮生长因子(VEGF)和碱性成纤维细胞生长因子(bFGF)的表达。结果:(1)与对照组相比较,积雪草甙干预的乳腺癌MCF-7细胞出现空泡、胞质外溢以及胞核皱缩等细胞凋亡现象,大量癌MCF-7细胞发生破碎死亡;(2)TUNEL技术法检测结果证实积雪草甙能够提高人乳腺癌MCF-7细胞凋亡率,与对照组比较差异具有统计学意义(P0.05),且呈时间依赖性;(3)积雪草甙干预的MCF-7细胞VEGF阳性表达和bFGF阳性表达显著低于对照组,差异具有统计学意义(P0.05),积雪草甙的抑制作用且呈时间依赖性。结论:积雪草甙不仅能够促进乳腺癌MCF-7细胞凋亡,而且能够降低VEGF和bFGF表达。     

The healing effects of Centella extract and asiaticoside on acetic acid induced gastric ulcers in rats

In this study, the healing effects of Centella asiatica water extract (CE) and asiaticoside (AC), an active constituent of CE, on acetic acid induced gastric ulcers (kissing ulcers) in rats were examined. CE was prepared from Centella asiatica dry plant and the concentration of AC in CE was quantitatively determined with the use of high performance liquid chromatography analysis. Different concentrations of CE and AC were orally administered to rats with kissing ulcers. They were found to reduce the size of the ulcers at day 3 and 7 in a dose-dependent manner, with a concomitant attenuation of myeloperoxidase activity at the ulcer tissues. Epithelial cell proliferation and angiogenesis were on the other hand promoted. The expression of basic fibroblast growth factor, an important angiogenic factor, was also upregulated in the ulcer tissues in rats treated with CE or AC. These results further suggest the potential use of Centella asiatica and its active ingredient as anti-gastric ulcers drugs.     

Characterisation of two phenotypes of <Emphasis Type="Italic">Centella asiatica</Emphasis> in Southern Africa through the composition of four triterpenoids in callus,cell suspensions and leaves

Two morphologically distinct phenotypes of Centella asiatica (Type-1 and Type-2) in South Africa were compared in relation to the levels of triterpenoid saponins with the aim of assessing their potential for biotechnological manipulation of triterpenoid synthesis. The metabolites investigated included madecassoside and asiaticoside and their sapogenins madecassic—and asiatic acid; produced in cultured undifferentiated cells (cell suspensions and calli) and leaves. Weight determination in plant cell suspensions and the accumulation of secondary metabolites after 16 days for Type-1 and 20 days for Type-2 were investigated since these secondary metabolites accumulate during the period that follows the active growth phase. The four triterpenoids of interest were analysed and quantified by HPLC in crude ethanolic extracts. A difference in bioactive triterpenoids was exhibited that was tissue specific and varied between the two phenotypes. The triterpenoids from leaf tissue were more easily quantifiable in each phenotype than in the case of the undifferentiated cells (callus and cell suspensions), which had lower, but still quantifiable, levels of these targeted secondary metabolites. Leaves contained the highest triterpenoid levels (ranging from 1.8 to 5% dry weight for the triterpenoid acids and their glycosides, respectively), with the free acids occurring in a ratio of approximately 1:2.5 in relation to the glycoside content.