Efficacy of Quercetin and Kaempferol from Methanolic Extracts of Adiantum lunulatum Burm. F. and Polystichum acrostichoides as Antidiabetic Activity

In present investigation, the aerial parts of two fern species viz. Polystichum acrostichoides (PA) and Adiantum lunulatum (AL) were used to evaluate the potent antidiabetic activity. Methanol solvent was used for extraction by soxhlation method followed by LC-MS analysis to identify the presence of compounds in both the extracts. Further, isolation of the major compounds was carried out and characterized by IR, mass and NMR techniques. Thereafter, in vitro α-amylase inhibitory activity for both the extracts was determined by comparing with acarbose as standard. Thereafter, α-glucosidase inhibition activity followed by glucose uptake was studied using L6 cell line study. Practical yield for both the fern extracts was calculated and observed A. lunulatum extract showed more yield (7 g) than P. acrostichoides (3 g). Based on the analytical data, isolated compound was identified as quercetin and kaempferol from the A. lunulatum and P. acrostichoides extracts, respectively. A. lunulatum extract even showed better dose dependent α-amylase inhibition and α-glucosidase inhibition activity than P. acrostichoides furthermore, L6 cell line study showed increased glucose uptake by A. lunulatum extract than P. acrostichoides extract when compared with standard insulin. Based on the findings, it appears that the both A. lunulatum and P. acrostichoides have the potential to be used as antidiabetic drugs due to presence of major isolated flavonoids i.e. quercetin and kaempferol as among the bioactive compounds. Antidiabetic efficacy was dosage dependent and A. lunulatum extract was more effective in inhibiting glucose uptake than P. acrostichoides extract.