Antidiabetic activity of Siraitia grosvenorii, Dimocarpus longan Lour. and Orthosiphon stamineus Benth. Extracts combinations in vitro and in silico

Abstract

Due to the economic burden created by diabetes, it is imperative to explore the potential of common dietary sources as complementary remedies for diabetic sufferers. The present study aims to evaluate the synergistic antidiabetic activity of combined extracts from Siraitia grosvenorii, Dimocarpus longan, and Orthosiphon stamineus in silico and in vitro, which include DPPH radical scavenging capacity, α-amylase inhibition, α-glucosidase inhibition, DPP-4 inhibition, cytotoxicity, and glucose uptake kinetics. The combination of S. grosvenorii + Dimocarpus longan + O. stamineus (SG + DL + OS) showed potential in inhibiting DPPH with an IC50 value of 7.21 ± 0.72 mg/ml, which also exhibited inhibitory effects on α-amylase, α-glucosidase, and DPP-4, with IC50 values of 8.63 ± 0.35 mg/ml, 5.41 ± 0.67 mg/ml, and 2.89 ± 0.09 mg/ml, respectively. Furthermore, it has been observed that the glucose uptake of L6 myoblasts can be significantly enhanced (P < 0.05) by treating different combinations. According to the results of XP docking and MM-GBSA analysis in silico, 26 and 32 compounds in the combination have significant interaction and stable binding ability with α-amylase and DPP-4 proteins, which can be used as α-amylase and DPP-4 inhibitors. Hence, it can be concluded that combinations of S. grosvenorii, D. longan, and O. stamineus have presented a viable therapeutic option for managing diabetes.