Hannan J M A, Marenah L, Ali L, Rokeya B, Flatt P R, Abdel-Wahab Y H A
Diabetes Research Group, School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland BT52 1SA, UK.
J Endocrinol. 2006 Apr;189(1):127-36. doi: 10.1677/joe.1.06615.
Ocimum sanctum leaves have previously been reported to reduce blood glucose when administered to rats and humans with diabetes. In the present study, the effects of ethanol extract and five partition fractions of O. sanctum leaves were studied on insulin secretion together with an evaluation of their mechanisms of action. The ethanol extract and each of the aqueous, butanol and ethylacetate fractions stimulated insulin secretion from perfused rat pancreas, isolated rat islets and a clonal rat beta-cell line in a concentration-dependent manner. The stimulatory effects of ethanol extract and each of these partition fractions were potentiated by glucose, isobutylmethylxanthine, tolbutamide and a depolarizing concentration of KCl. Inhibition of the secretory effect was observed with diazoxide, verapamil and Ca2+ removal. In contrast, the stimulatory effects of the chloroform and hexane partition fractions were associated with decreased cell viability and were unaltered by diazoxide and verapamil. The ethanol extract and the five fractions increased intracellular Ca2+ in clonal BRIN-BD11 cells, being partly attenuated by the addition of verapamil. These findings indicated that constituents of O. sanctum leaf extracts have stimulatory effects on physiological pathways of insulin secretion which may underlie its reported antidiabetic action.
此前有报道称，给糖尿病大鼠和人类服用神圣罗勒叶可降低血糖。在本研究中，研究了神圣罗勒叶乙醇提取物和五个分离部位对胰岛素分泌的影响，并评估了其作用机制。乙醇提取物以及水相、丁醇和乙酸乙酯部位均以浓度依赖的方式刺激灌注大鼠胰腺、分离的大鼠胰岛和克隆大鼠β细胞系分泌胰岛素。葡萄糖、异丁基甲基黄嘌呤、甲苯磺丁脲和去极化浓度的氯化钾可增强乙醇提取物和这些分离部位的刺激作用。二氮嗪、维拉帕米和去除Ca2+可观察到分泌作用受到抑制。相比之下，氯仿和己烷分离部位的刺激作用与细胞活力降低有关，且不受二氮嗪和维拉帕米的影响。乙醇提取物和五个部位可增加克隆BRIN-BD11细胞内的Ca2+，加入维拉帕米后部分减弱。这些发现表明，神圣罗勒叶提取物的成分对胰岛素分泌的生理途径具有刺激作用，这可能是其报道的抗糖尿病作用的基础。
