Comparison of phytochemicals, antioxidant and anti-cholinesterase activity of unripe and ripe fruit of Sonneratia caseolaris

Sonneratia caseolaris, also known as mangrove apple produces the edible fruit which can be found mainly on tidal mud in mangroves area. Since this fruit is considered as underutilized fruit as it is not fully discovered for its potential health benefits and not fully commercialized, hence this study aimed to determine the phytochemicals contents (i.e. total flavonoid, phenolic, anthocyanins and carotenoids contents), antioxidant and anticholinesterase activity of different parts (flesh and stem cap) of the unripe and ripe fruit extracts. Phytochemicals, antioxidant and anti-cholinesterase activities were determined using standard methods of spectrophotometric analysis. The flesh part of unripe S. caseolaris displayed the highest total phenolic, flavonoid and carotenoid contents as compared to the other parts in 80% methanol extract with the values of 67.67±0.10 mg (GAE/g), 37.06±0.30 mg (RE/g) and 5.41±0.10 mg (BC/100 g), respectively. The flesh part of unripe S. caseolaris in 80% methanol extract exhibited the best antioxidant properties in three different assays (i.e. DPPH, FRAP and ABTS) with the values of 98.32±0.28%, 67.72±0.74 mmol/g and 91.24±1.23 mg/g, respectively. The acetylcholinesterase inhibition also was found to be higher in the flesh part of unripe 80% methanol S. caseolaris extract with 47.18±0.68% at the concentration of 250 µg/mL. Therefore, utilization of this fruit as natural antioxidant and acetylcholinesterase inhibition sources may develop new pharmaceutical and nutraceutical products.