Angiogenesis modulation by Plectranthus amboinicus leaf extract and its fractions on chorioallantoic membrane and tumor induced angiogenesis

摘要

The objective of the present study was to evaluate the angiogenesis modulation by Plectranthus amboinicus leaf extract and its fractions on Chorioallantoic membrane and tumour induced angiogenesis. Powdered leaves of Plectranthus amboinicus were extracted with methanol using soxhlet apparatus. The dried extract was subjected to qualitative, quantitative analysis and assessed for its potential free radical scavenging activity. The effect of crude methanol extract on vascularisation was assessed in chick chorioallantoic membrane (CAM) model. The extract was then fractionated with petroleum ether, chloroform, ethyl acetate and n-butanol and the fractions were evaluated for angiogenesis inhibitory activity by CAM assay. The potent fraction and crude extract were evaluated for angiogenesis inhibitory activity in murine ascites tumour model of Erhlich ascites carcinoma. The fraction was subjected to Gas chromatography–mass spectrometry (GC-MS) analysis. The crude methanol extract showed a significant inhibitory activity on vascularisation in CAM model. Among the fractions, n-butanol fraction showed a potent angiogenesis inhibition in CAM model. In peritoneal lining of Ehrlich ascites carcinoma (EAC) bearing mice, crude methanol extract and n-butanol fraction showed a significant decrease in number of blood vessels compared to EAC control mice. The preliminary qualitative and quantitative analysis showed the presence of flavonoids, tannins, phenolic compounds and showed a potent free radical scavenging activity. Gas chromatography–mass spectrometry analysis revealed the presence of (1) Phenol 2-methyl-6-(2-propenyl)-, (2) Phenol 2,6-dimethoxy, (3) 2-Methoxy-4-vinylphenol, (4) Phenol 4-methoxy-2,3,6-trimethyl (5) 3-Methyl-4-isopropylphenol in n-butanol fraction of Plectranthus amboinicus. These results demonstrate the anti-angiogenic activity of Plectranthus amboinicus leaves. The plant may serve as potential source for protection and treatment of cancer and could bring hope to millions of sufferers with cancer.