Antioxidant activities and α-glucosidase inhibitory potential of crude extracts from five cultivars of Antidesma thwaitesianum Müll. Arg.

International Journal of Agricultural Technology 2023 Vol. 19(2):639-654
Available online http://www.ijat-aatsea.com
ISSN 2630-0192 (Online)

Abstract The α-glucosidase inhibitory potential, total phenolic and flavonoid contents for
antioxidant activities of 30 crude extracts of various parts of Antidesma thwaitesianum
including leaves, flowers, immature green fruits, mature red fruits, ripe black fruits, and
seeds were investigated. The results showed that the α-glucosidase inhibitory activity was
not observed in the ripe black fruits and seeds of all cultivars. The high α-glucosidase
inhibitory potential was detected in the leaves and flowers of all the tested cultivars, with
the IC50 ranged of 0.22 – 2.63 µg/mL. Notably, the highest α-glucosidase inhibitory activity
was found in the Sang Koh 2 flowers (IC50 = 0.22 µg/mL), followed by the flowers of Kam
Lai (IC50 = 0.35 µg/mL) and Phu Phan Thong (IC50 = 0.35 µg/mL). While the total
phenolics were predominant in the immature green and ripe red fruits (515.10 – 1230 mg
GAE/100 g crude extract) the total flavonoids were found in all parts of cultivars (123.53 –
490.83 mg CE/100 g crude extract). It is indicated by the DPPH, ABTS+
and FRAP values, all cultivars showed a good source of antioxidant agents. Hence, this plant species is an
ideal antihyperglycemic agent for treating diabetes.
Keywords: Mao Luang (Antidesma thwaitesianum Müll.), Phytochemicals, Alphaglucosidase