Comparative antioxidant and antidiabetic effects of Syzygium polyanthum leaf and Momordica charantia fruit extracts

Abstract

The study was aimed to perform aqueous extraction of two plants using different extraction methods, and evaluate their antioxidant and antidiabetic potential. Plant materials were extracted by maceration, soxhlet, sonication and fresh juice methods to produce aqueous extracts. In vitro antioxidant DPPH (1,1-diphenyl-2- picrylhydrazyl) and FRAP (Ferric reducing antioxidant power), antidiabetic α–amylase and α–glucosidase enzyme inhibitory assays were carried out on the extracts. Extracts of Syzygium polyanthum demonstrated better free radical scavenging and antidiabetic activity than Momordica charantia. It was observed that the % inhibition of DPPH by fresh juice of S. polyanthum was 64.93 similar to quercetin 69.21 (p>0.05). Its FRAP value (69.05) was significantly (p<0.05) higher than Quercetin (63.27). Its fresh juice also demonstrated significant inhibitory actions (p<0.05) against α-amylase (92.21%) and α– glucosidase (96.06%) than acarbose. It is concluded that extracts had varied results due to differences in their chemical composition as noticed in LC-MS. The fresh juice of S. polyanthum has superior in vitro antioxidant and antidiabetic activities. Therefore, intake of exogenous antioxidants in the form of fresh juices of some herbs can help the body to scavenge free radicals and exert hyperglycaemic control in post prandial hyperglycaemia.