EVALUATION OF Î±-GLUCOSIDASE INHIBITORY POTENTIAL OF METHANOLIC LEAF EXTRACT OF OCIMUM CANUM
Keywords:Ocimum canum, Nil, Hyperglycemia, Rosmarinic acid, and Ursolic acid
Objective: The present investigation was designed to study the inhibitory effects of methanolic leaf extract of Ocimum canum (O. canum) on Î±-glucosidase using in vitro model followed by an assessment of bioactive compounds.
Methods: The methanolic leaf extract was prepared by Soxhlet extraction method and partially purified by thin layer chromatography (TLC). Each band was subjected to Î±-glucosidase inhibition study. The positive bands were further characterized by high-performance liquid chromatography (HPLC) and quadrupole time of flight (Q-TOF) micro mass spectrometer.
Results: Out of the several combinations of solvent systems, toluene, ethyl acetate and formic acid combination in the ratio of 7:2:1 revealed 5 bands on the TLC sheet. Among all the TLC bands, 2 bands (band A and B) showed the significant inhibitory effect on Î±-glucosidase activity. HPLC analysis of band A and B revealed the presence of two important polyphenolic compounds, namely rosmarinic acid (RA) and ursolic acid (UA). Q-TOF micromass spectrometer analysis revealed the percentage availability of RA, caffeic acid, tartaric acid, quercetin and other polyphenolic components in the bioactive bands.
Conclusion: The study revealed that methanolic leaf extract of O. canum exhibits potent inhibition of Î±-glucosidase activity. Inhibition of Î±-glucosidase activity might be attributed to the presence of the polyphenolic compounds like RA and UA. Therefore, this finding can lead to the development of natural Î±-glucosidase inhibitors by the O. canum leaf extract.
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