GC–MS analysis of phytochemical constituents of methanolic fraction of Annona muricata leaf and its inhibition against two key enzymes linked to type II diabetes

Abstract

Plant based phytonutrients have been recommended as an alternative in the management of diabetes mellitus (DM), a metabolic disorder that has been recognized as a threat to humans across the globe. The current study therefore, sought to appraise the probable antioxidant and antidiabetic potentials of methanolic fraction of Annona muricata leaf (MetOHAm) via the inhibition of carbohydrate-hydrolyzing enzymes such as α-amylase and α-glucosidase, as well as analyze for the available bioactive components using the GC–MS technique. The antioxidant quantification assays on MetOHAm revealed ferric reducing power capacity (25.80 mg/100 g), hydroxyl radical scavenging ability (55.3 mg/100 g) and singlet oxygen scavenging capacity (46.78 mg/100 g) in comparison with gallic acid, whereas, a strong inhibition against DPPH free radical (25.80–93.98%) in concentration-dependent manner was revealed when compared with butylated hydroxytoluene (BHT) as reference. Also, MetOHAm exhibited a significant (p < 0.05) inhibition against α-amylase (IC50= 112.27 mg/ml) and α-glucosidase (IC50= 34.85 mg/ml) carbohydrate-hydrolyzing activities compared with acarbose, a known starch blocker. Furthermore, gas chromatography-mass spectrometry (GC–MS) analysis revealed the available bioactive compounds in MetOHAm. Therefore, presence of these vital bioactive compounds identified in different percentage compositions from MetOHAm could probably be responsible for the antioxidant and enzyme inhibitory activities exhibited by MetOHAm in vitro.