Comparative biochemical evaluation of the proximate content, antioxidant properties, and phytochemical constituents of ethnomedicinally important Docynia indica from Northeast India

Docynia indica (wild apple) is an underutilized wild edible fruit endemic to the Indo-Burma biodiversity hotspot having ethnomedicinal importance. In this study, we investigated the proximate, antioxidant, and biochemical aspects, focusing on alkaloids, phenolics, and flavonoids in D. indica. Antioxidant activity of methanolic extract of fruit, flower, and leaf were compared using 2,2 diphenyl-1-picrylhydrazyl and 2,2’-azino-bis (3-ethyle benzothiazoline-6-sulfonic acid) assay, total antioxidant content of all the three extracts were quantified by phosphomolybdenum assay. The percentage concentration of total alkaloids was estimated, and the total phenolic and flavonoid content of all three extracts was quantified. Comparative studies on carbohydrate and protein content reveal higher concentrations in flowers (58.25%) and leaves (73.5%) compared to fruit. Vitamin C content was found to be high in the leaf (0.98 mg/100 g) compared to fruit and flower. Methanolic extract of fruit, flower, and leaf showed effective results for antioxidant activity. Leaf extract was found to have the highest antioxidant activity with an IC50 value of 26.854 µg/mL for DPPH and 7.06 µg/mL for ABTS. The percentage alkaloid concentration was higher in the methanolic extract of the leaf (24%). Total phenolic and flavonoid content were also found to be higher in the methanolic extract of the leaf with (68.33 ± 0.0035 mg GAE/gm of extract) and (92.37 ± 0.001 mg QE/gm of extract), respectively. Leaf has more potential health benefits compared to fruit and flowers of Docynia indica with high antioxidant activity, phenolics, and flavonoid content. Further studies on its efficacy and molecular identification may lead to novel drug discovery.