Role of Deglycosylation for Antioxidant Potential of Selected Plant Extracts

Deglycosylation has previously been suggested to modulate the biological activities of various phytochemicals. The current study was designed to evaluate the effects of deglycosylation on antioxidant potential of crude methanolic extracts (CMEs) of four medicinal plants: Adhatoda vasica, Skimmia laureola, Olea ferruginea, and Cymbopogon citratus. The CMEs were prepared in 80% methanol and their antioxidant activity was measured using DPPH (diphenyl picryl hydrazyl) photometric assay. The resultant IC50 values were 82 μg/mL for O. ferruginea, 127 μg/mL for S. laureola, 169 μg/mL for C. citrates, 170 μg/mL for A. vasica, and 3.1 μg/mL for ascorbic acid, which was used as a standard. Glycosidase enzyme was extracted from Medicago sativa (alfalfa) seeds and assayed chromogenically using X-gal as its substrate. The glycosidase enzyme successfully deglycosylated CMEs of all the four plants. These degylosylated extracts were also analyzed for their antioxidant activities. New IC50 values were 52 μg/mL for O. ferruginea, 71 μg/mL for S. laureola, 103 μg/mL for A. vasica, and 111 μg/mL for C. citratus. These observations show a significant increase in the antioxidant potential of all four CMEs as a result of their deglycosylation. All results were analyzed statistically and significant difference (p = 0) was established between CMEs and deglycosylated CMEs of all the four selected plants tested separately.