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

BACKGROUND The fruit of Cucurbita ficifolia Bouché is known in Mexico as ‘chilacayote’. The scientific interest that C. ficifolia Bouché has acquired is due to its important hypoglycemic effect. The present research aimed (i) to discover whether this hypoglycemic property is present at 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 effects were bioassayed using groups of normal mice with diabetes induced by streptozotocin 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 to have the highest concentration at 15 days of development. Extracts at 15 days showed a hypoglycemic effect that was 11% greater than that of glibenclamide in diabetized mice. CONCLUSION All stages of development of C. ficifolia fruit had a hypoglycemic effect; however, the aqueous extract from the fruit at 15 days of development showed a better effect than glibenclamide. This finding highlights the potential of this maturity stage, and shows that it is appropriate for inclusion in treatments of type 2 diabetes mellitus. The results also indicate that phenolic compounds are mainly responsible for this effect and not d ‐ chiro ‐inositol as previously thought. © 2020 Society of Chemical Industry