MedChem Herbal Research Group, Faculty of Pharmacy, Universiti Teknologi MARA, 42300 Puncak Alam, Selangor, Malaysia.
J Ethnopharmacol. 2012 Aug 1;142(3):776-81. doi: 10.1016/j.jep.2012.05.062. Epub 2012 Jun 7.
The leaves of Ficus deltoidea are used as a traditional medicine by diabetes patients in Malaysia.
The objective of the study is to identify and evaluate bioactive constituents with in vivo α-glucosidase inhibition.
The partitioned extracts, subfractions and pure bioactive constituents were subjected to α-glucosidase inhibition assay. The identified bioactive constituents were administered orally to sucrose loaded normoglycemic mice and induced diabetic rats. The postprandial blood glucose levels were monitored at 30 min interval. Acute toxicity was evaluated in both normoglycemic mice and induced diabetic rats.
Bioactivity guided fractionation led to the isolation of both vitexin (1) and isovitexin (2). Oral administration of 1mg/kg of either vitexin (1) or isovitexin (2) significantly (p<0.05) reduced the postprandial blood glucose level in sucrose loaded normoglycemic mice at 30 min. The percentage of postprandial blood glucose reduction was highest in sucrose loaded induced diabetic rats administered orally with 200mg/kg of vitexin (1) or 100mg/kg of isovitexin (2). Both vitexin (1) and isovitexin (2) did not exert any signs of toxicity at the highest dose of 2g/kg administered orally to normoglycemic mice and induced diabetic rats.
Both the C-glycosyl bioflavonoids, namely, vitexin (1) and isovitexin (2) exhibited in vivo α-glucosidase inhibition.
在马来西亚，糖尿病患者将榕树叶用作传统药物。
本研究的目的是鉴定和评估具有体内α-葡萄糖苷酶抑制作用的生物活性成分。
将分离的提取物、亚馏分和纯生物活性成分进行α-葡萄糖苷酶抑制测定。将鉴定出的生物活性成分给予蔗糖负荷的正常血糖小鼠和诱导的糖尿病大鼠口服。在 30 分钟间隔监测餐后血糖水平。在正常血糖小鼠和诱导的糖尿病大鼠中评估急性毒性。
基于生物活性的分步分离导致分离出荭草素（1）和异荭草素（2）。以 1mg/kg 的剂量口服给予荭草素（1）或异荭草素（2）均可显著（p<0.05）降低蔗糖负荷的正常血糖小鼠的餐后血糖水平在 30 分钟。以 200mg/kg 的剂量口服给予蔗糖负荷诱导的糖尿病大鼠的荭草素（1）或 100mg/kg 的异荭草素（2），餐后血糖降低的百分比最高。荭草素（1）和异荭草素（2）在最高剂量 2g/kg 口服给予正常血糖小鼠和诱导的糖尿病大鼠时均未表现出任何毒性迹象。
两种 C-糖苷生物类黄酮，即荭草素（1）和异荭草素（2），均表现出体内α-葡萄糖苷酶抑制作用。
