Phytochemical Investigation and In Vitro Antidiabetic Potential of Leaf Extracts of Himalayan Herb: Allium stracheyi Baker

Abstract

Background: Various species of the genus Allium have been reported to exhibit antidiabetic potential. Among various species, Allium stracheyi Baker is one of the most popular and important ethnobotanical traditional perennial Himalayan seasoning herbs belonging to the family Alliaceae. Since no scientific studies have been carried out to assess the potential of species Allium stracheyi Baker in reducing blood sugar levels. Therefore, the present research work is aimed to screen different leaf extracts for the presence of bioactive phytochemicals and evaluate the in vitro antidiabetic potential of each extract. Aim: To ascertain phytochemical composition in Allium stracheyi Baker leaf extracts by using preliminary qualitative and quantitative screening methods and assessment of antidiabetic potential by in vitro enzymatic assays. Methods: The successive extraction of Allium stracheyi Baker leaf was carried out by using a sequence of solvents with increasing polarity including petroleum ether, methanol, hydroalcoholic and water by soxhlation apparatus. The concentrated extracts were subjected to preliminary phytochemical analysis for the presence or absence of active phytochemicals and their quantity in extract followed by determination of antidiabetic potential by application of standard in vitro enzymatic assays. Results: Phytochemical screening on each leaf extract confirmed the presence of various bioactive phytochemicals. Results of quantitative screening showed that the methanolic extract possesses the highest amount of phenolic and flavonoids which may contribute to the antidiabetic potential of the plant. All the extracts demonstrated marked antidiabetic potential on in vitro enzymatic (α-amylase and α-glucosidase) assays. Additionally, methanolic extract was the only one of the tested extracts with a significant antidiabetic potential. Conclusion: Research findings concluded that methanol leaf extract exhibited significant antidiabetic potential because of the existence of phenolic compounds as well as flavonoids in the majority. Further additional studies on plant phytochemicals are strongly suggested to isolate and purify the major bioactive phenolics and flavonoids from methanolic extract to confirm its antidiabetic potential in in vivo studies. Major Findings: This study’s main finding is that, out of all the extracts, the methanolic extract of Allium stracheyi Baker was the most effective at inhibiting the activity of the alpha-glucosidase enzyme (IC50=32.92 μg/ml at 100 µg/ml) and the alpha-amylase enzyme (IC50=50.51 μg/m at 100 µg/ml), which suggests that it may be used to treat diabetes. The high concentration of polyphenolic chemicals, which are followed by tannins, steroids, alkaloids, and saponins, is what causes this activity.