Cucurbitane-Type Triterpenoids from the Blood Glucose-Lowering Extracts of Coccinia indica and Momordica balsamina Fruits

CONTEXT: Few vegetables that are commonly consumed in India as part of diet have been claimed for their antidiabetic potential. OBJECTIVE: The present study was aimed at evaluating preventive effects of cucurbit vegetables namely, Coccinia indica and Momordica balsamina belonging to family Cucurbitaceae in diabetic hyperglycemia. MATERIALS AND METHODS: The fruits of M. balsamina and C. indica were extracted with chloroform and fractionated with hexane to prepare an extract rich in moderately polar components. These extracts were used for evaluating the effect of these cucurbits in nicotinamide/streptozotocin-induced type 2 diabetes. Streptozotocin–nicotinamide-induced diabetic animals were orally treated with chloroform extract of fruits (250 mg/kg BW) given daily for a week separately. RESULTS: Both the extracts reduced fasting blood glucose significantly (P < 0.05 versus diabetic control) when estimated on seventh day of treatments. Pretreatment with fruit extracts for 7 days also blunted the OGTT (oral glucose tolerance test) curve. Results indicated that C. indica and M. balsamina fruits possess beneficial effects in diabetes by lowering elevated blood glucose level. Six cucurbitane-type triterpenoids were isolated from bioactive extracts of C. indica ((1-3) and M. balsamina (4-6). The structures of these compounds were elucidated on the basis of spectroscopic data analysis. CONCLUSION: The study concludes that the inclusion of C. indica and M. balsamina fruits in food can be useful for newly diagnosed diabetic patients or highrisk group of population for glycemic control. SUMMARY: “Cucurbitane-type triterpenoids from the blood glucose-lowering extracts of Coccinia indica and M. balsamina fruit” The beneficial effects of chloroform extracts of vegetal cucurbits namely C. indica (Ivy gourd) and M. balsamina (Balsam apple) in streptozotocin-nicotinamide (STZ-NA)-induced diabetic rats has been evaluated. The isolation and characterization of six cucurbitacins from bioactive extracts of C. indica (Coccinoside A, B, and C) and M. balsamina (cucurbit-5, 7-dien-3ß-ol, cucurbita-5-en-3ß-ol-3-O-ß-d-glucopyranoside, and cucurbit-5-en-3ß-ol-3-O-ß-d-glucopyranosyl-(4’→1”)-O-ß-d-glucopyranoside) have been reported for the first time. The study concludes that the inclusion of C. indica and M. balsamina fruits in food can be useful for newly diagnosed diabetic patients or high risk group of population for glycemic control. Abbreviation used: C: indica (Coccinia indica), M: balsamina (Momordica balsamina), Kbr: Potassium bromide, FTIR: Fourier transform infrared spectroscopy, COSY: Corelated Spectroscopy, DEPT: Distortionless Enhancement by Polarization Transfer, DMSO: Dimethyl sulfoxide, TMS: tetramethylsilane, ESI-MS: Electrospray Ionization mass spectrometry, TLC: thin layer chromatography, STZ-NA: Streptozotocin-nicotinamide, CMC: carboxy methyl cellulose, BW: body weight, ANOVA: analysis of variance, AUC: area under curve