Phytochemical screening and antioxidants in vitro bioaccessibility of Coccinia grandis: an underutilized wild edible plant in Sri Lanka

Abstract Coccinia grandis (L.) J. Voigt is an underutilized wild edible plant in Sri Lanka that consists of a number of medicinal and nutritional values. Underutilized wild edibles have multiple positive health effects for humans, attributed to their bioactive compounds including minerals, antioxidants and phytochemicals. Even though these plant extracts are enriched with a number of bioactive compounds, the bioaccessibility as well as, the bioavailability of those compounds significantly depend on the structure and the form in which they are introduced into the human body. Therefore, crude extract of C. grandis was subjected to evaluate their phytochemicals, antioxidant activity and antioxidant in vitro bioaccessibility fraction of digested samples were calculated. Organic solvents namely, ethanol, hexane and chloroform were used to extract the samples and qualitative in vitro phytochemical screening was conducted to screen for the presence or absence of the phytochemicals. Results indicate that alkaloids, saponins, flavonoids, tannins, phenols, quinone, terpenoids and steroids are the available phytochemicals in every organic extract of C. grandis. Evaluation of antioxidant activity was done by two different assays such as DPPH and ABTS. In the hexane extract it was detected relatively high antioxidant activity as 0.008 mg/mL (IC50) in DPPH assay and 561.94 mg TEAC/ g in ABTS assay. Antioxidant bioaccessibility was also tested through an in vitro digestion model and a 42% bioavailability rate was indicated against the corresponding antioxidant activity in un-digested ethanol extract of C. grandis. Based on the presence of various phytochemicals and is a natural source of antioxidants, this species can be used to improve the human diet, especially for low-income people.