Hypoglycemic effect and bioactive compounds associated with the maturity stages of Cucurbita ficifolia Bouché fruit

Background: The fruit of Cucurbita ficifolia Bouché is known in Mexico as 'chilacayote'. The scientific interest that Cucurbita ficifolia Bouché has acquired is due to its important hypoglycemic effect. The present research aimed to knowledge (i) if this hypoglycemic property is present in different stages of development of this fruit and (ii) to characterize some bioactive compounds with antioxidant or anti-inflammatory properties. Ethylene production, respiration rate, and maturity indices were determined during fruit development. The chemical characterization of the aqueous extracts of each stage of maturity studied was determined and their hypoglycemic effect was bioassay using groups of normal mice and streptozotocin-induced diabetic at a dose of 500 mg^-1 kg^-1 body weight.

Results: Respiration rate and ethylene production showed a typical pattern for non-climacteric fruit and the quality parameters did not show significant changes. Phenolic compounds such as gallic acid and chlorogenic acid were found whit the highest concentration at 15 days of development. Extracts at 15 days showed an 11% greater hypoglycemic effect than glibenclamide in diabetized mice.

Conclusion: All stages of development of C. ficifolia fruit had a hypoglycemic effect, however, the aqueous extract from the fruit of 15 days of development showed a remarkable and better effect than glibenclamide. This finding highlights the potential of this maturity stage as the most appropriate to be included in treatments of type 2 diabetes mellitus. Besides, results indicate that the phenolic compounds are the main responsible of this effect and not the D-chiro-inositol as previously thought. This article is protected by copyright. All rights reserved.

Keywords: Cucurbita ficifolia; Hypoglycemic effect; phenolic compounds; stages of development; type 2 diabetes mellitus.