Antioxidant and scavenging activity of skyrin on free radical and some reactive oxygen species.

Abstract

Skyrin is a natural product from some botanical species (fungi) and the first small molecular weight nonpeptidic antidiabetic agents. Now, the objective of this study was to investigate the ability of skyrin to inhibit free radical and some reactive oxygen species as .OH, 1O2, H2O2 generated in cell-free systems using isoluminol and luminol- enhanced chemiluminescence and electronic absorption spectra as monitors. In the presence of skyrin a dose-dependent inhibition period was observed in this system as assayed by isoluminol-enhanced chemiluminescence (ILCL) in the presence of horseradish peroxidase (HRP), as well as by luminol-enhanced chemiluminescence (LCL) in the presence of H2O2 or ferrous ion. On the other hand, skyrin showed an efficient scavenging activity of galvanoxyl radical in ethanolic solutions. In a separate experiment the trapping of singlet oxygen (1O2) generated by rose bengal in the presence of skyrin was observed. The antioxidant activity of skyrin was compared with that of known antioxidants as emodin, dipyridamole, vitamins C and E in different assays as also in the lipid peroxidation. These results suggest that skyrin scavenge reactive oxygen and free radicals species in a comparative grade that emodin, vitamin C and E or dipyridamole.

Keywords

• Chemiluminescence
• skyrin
• emodin
• free radical scavenger
• antioxidant activity