Phytochemical profile, antioxidant, anti-inflammatory and hypoglycemic potential of hydroalcoholic extracts from Citrus medica L. cv Diamante flowers, leaves and fruits at two maturity stages

Since the past decade consumption of certain foods has been reported to have a positive effect on health. The object of the study was to determine for the first time the chemical composition and the antioxidant, anti-inflammatory and hypoglycemic potential of Citrus medica L. cv Diamante flowers, leaves and fruits (endocarp and mesocarp) at two maturity stages. Flowers and leaves were characterized by the highest total phenols and flavonoids content. A declining trend was observed during maturity of fruits for both phenols and flavonoids. The antioxidant activity evaluated by the β-carotene bleaching test showed a strong activity for flowers and endocarp of mature fruits with IC₅₀ values of 2.8 μg/mL and 3.5 μg/mL, respectively, after 30 min of incubation. Interestingly, the mature fruits endocarp (IC₅₀ value of 426.0 μg/mL) could inhibit α-amylase with an IC₅₀ value 2-fold higher than immature fruits. None of the tested extracts affected the proliferation of human skin fibroblasts 142BR. The obtained results suggest a potential use of C. medica L. cv Diamante as new valuable Citrus species with functional properties for food or nutraceutical product on the basis of high content of phytochemicals.