UHPLC-QTOF-MS/MS based phytochemical characterization and anti-hyperglycemic prospective of hydro-ethanolic leaf extract of Butea monosperma

Abstract

Butea monosperma is one of the extensively used plants in traditional system of medicines for many therapeutic purposes. In this study, the antioxidant activity, α-glucosidase and α-amylase inhibition properties of freeze drying assisted ultrasonicated leaf extracts (hydro-ethanolic) of B. monosperma have been investigated. The findings revealed that 60% ethanolic fraction exhibited high phenolic contents, total flavonoid contents, highest antioxidant activity, and promising α-glucosidase and α-amylase inhibitions. The UHPLC-QTOF-MS/MS analysis indicated the presence of notable metabolites of significant medicinal potential including apigenin, apigenin C-hexoside C-pentoside, apigenin C-hexoside C-hexoside, apigenin-6,8-di-C-pentoside and genistin etc., in B. monosperma leave extract. Docking studies were carried out to determine the possible role of each phytochemical present in leaf extract. Binding affinity data and interaction pattern of all the possible phytochemicals in leaf extract of B. monosperma revealed that they can inhibit α-amylase and α-glucosidase synergistically to prevent hyperglycemia.

Figure 1

Extraction yield (%) of different hydro-ethanolic extracts.

Figure 2

DPPH scavenging potential of extracts of different concentrations.

Figure 3

Total antioxidant power assay to assess anti-oxidant activity.

Figure 4

Comparative percentage inhibition for β-Carotene bleaching by 60% extracts and BHA.

Figure 5

In-vitro α-amylase inhibitory potential of B. monosperma extracts.

Figure 6

α-glucosidase inhibitory potential of B. monosperma leaf extracts.

Figure 7

Full chromatogram of 60% extract of B. monosperma leaf in negative ion mode.

Figure 8

Mass spectra of identified compounds.

Figure 9

Proposed fragmentation mechanism of bioactives from 60% ethanolic leaf extract of B. monosperma.

Figure 10

(a) The overlaid ribbon diagram of validation set into the binding site of porcine pancreatic α-amylase (PDB code 1OSE). (b) The overlaid ribbon diagram of isolated phytochemicals into the binding site of porcine pancreatic α-amylase; (c–e) The overlaid ribbon diagrams of phytochemicals 1, 3 and 6 and native ligand acarbose in to the binding site of porcine pancreatic α-amylase.

Figure 11

(a) The overlaid ribbon diagram of apigenin C-hexoside-C-pentoside (7) and acarbose into the binding site of porcine pancreatic α-amylase (b) Close-up depiction of the lowest-energy three-dimensional (3-D) docking pose of 7.

Figure 12

(a) Three-dimensional (3-D) docking pose of Aapigenin-6,8-di-C-pentoside (6) into the active site of homology modeled α-glucosidase.; (b) Close-up depiction of the lowest-energy three-dimensional (3-D) docking pose of 6.