Green solvent-based extraction of three Fabaceae species: A potential antioxidant, anti-diabetic, and anti-leishmanial agents.

The Fabaceae is renowned for its diverse range of chemical compounds with significant biological activities, making it a valuable subject for pharmacological studies. The chemical composition and biological activities of three Fabaceae species were investigated using methanol separately and in combination with dimethyl sulfoxide (DMSO) and glycerol for extraction. The results revealed the highest phenolic (49.59 ± 0.38 mg gallic acid equivalent/g), flavonoid (29.16 ± 0.39 mg rutin equivalent/g), and alkaloid (14.23 ± 0.54 mg atropine equivalent/g) contents in the Caesalpinia decapetala methanol extracts. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and DNA protection activity were the highest (0.88 ± 0.43 μg/mL IC50 and 2149.26 band intensity) in Albizia julibrissin methanol extracts. The α-amylase activity was highest in all methanol extracts (<15 μg/mL IC50 values), while the α-glucosidase inhibition potential was highest (<1 μg/mL IC50 value) in the methanol-glycerol and methanol-DMSO extracts. Pearson coefficient analysis showed a strong positive correlation between the DPPH and α-amylase assays and phytochemicals. Anti-leishmanial activity was observed in decreasing order: A. julibrissin (74.75 %) > C. decapetala (70.86 %) > Indigofera atropurpurea (65.34 %). Gas chromatography-mass spectrometry revealed 33 volatile compounds and, aamong these (Z)-9-octadecenamide was detected in the highest concentration ranging from 21.85 to 38.61 %. Only the methanol extracts of the examined species could be assessed for in vivo studies for immediate applications.