Chemical compositions, in vitro assessments of antioxidant and antidiabetic potentials of Cyanomentra vogelii Hook. F.

Abstract

The study investigates the chemical composition and antioxidant and antidiabetic activities of Cyanomentra vogelii Hook. F. Hexane, ethylacetate and methanol extracts of C. vogelii were obtained using a cold extraction method. Phytochemical analysis of the extracts was achieved using standard methods: in vitro assays were employed to assess antioxidant activities while antidiabetic potentials were evaluated against the action of ?-amylase and ?-glucosidase. The chemical composition of the extract was identified using gas chromatography-mass spectrometry (GC-MS) analysis. The methanol extract of C. vogelii displayed the highest quantity of phenol (68.93 mg gallic acid g-1) and flavonoids (74.84 mg quercetin g-1), while the ethylacetate extract exhibited the highest content of proanthocyanidins (33.21 mg catechin g-1). The methanol extract exhibited significantly potent inhibition (P < .05) – more than hexane and ethylacetate extracts – against 1,1-diphenyl-2-picryl-hydrazyl (DPPH), hydroxyl (OH) and 2,2-azino-bis (3-ethylbenzothiazoline (ABTS) radicals at half maximal inhibitory concentrations (IC50) of 0.58, 0.19 and 0.46 mg/mL, respectively, while hexane extract showed higher metal chelating activity (P < .05) at 0.06 mg/mL. Hexane extract displayed better antidiabetic activities, as revealed by its moderate ?-amylase (2.54 mg/mL) and potent ?-glucosidase (0.53 mg/mL) inhibition compared to other extracts and acarbose. Mixed non-competitive and competitive modes of inhibition were elicited by the hexane extract against the activity of ?-amylase and ?-glucosidase, respectively. The major chemical components with reported antioxidant and antidiabetic activities identified from GC-MS analysis of the methanol extract include phytol (7.26%), n-hexadecanoic acid (5.95%), caryophyllene (1.70%) and nerolidol (2.22%). Cyanomentra vogelii extract contains active phytochemicals with therapeutic potential in the management of diabetes and oxidative stress-related diseases.