In vitro antidiabetic activity of “green tea” soursop leaves brew through α-glucosidase inhibition

Soursop leaves contain phytochemical compounds that can inhibit α-glucosidase enzyme activity; thus, they show potentiality as an antidiabetic agent. This research was aimed to observe the effect of brewing time and temperature towards inhibition of α-glucosidase enzyme activity and also to observe the physical, chemical and organoleptic characteristics of the brew. Initially, soursop leaves brew was prepared using green tea preparation method. Then, soursop leaves were brewed at 80 ^oC, 90 ^oC and 100 ^oC for 15, 30 and 45 minutes. Results showed soursop leaves brew contained tannin, flavonoids and triterpenoid. The best time and temperature combination, which had the highest inhibition towards α-glucosidase enzyme activity (showed by the lowest IC ₅₀ value), was 100 ^oC and 30 minutes of brewing with IC ₅₀ value of 396.70 ppm, phenolic content of 205.37 mg GAE/L, tannin content of 100.33 mg CE/L and flavonoids content of 99.97 mg QE/L. The brew was categorized as non toxic with LC ₅₀ value of 3801.89 µg/ml. The brew had reddish yellow colour and soursop leaves specific aroma, which was slightly not preferred by the panelists.