Effects of antioxidant xanthones from Gentiana dinarica on Acantoscelides obtectus aging in vivo

Abstract

Free radical scavenging activities of xanthones: norswertianin-1-O-primeveroside and norswertianin-8-O-primeveroside isolated from the roots of G. dinarica towards stable free radical 1,1-diphenyl-2-pic-rylhydrazyl (DPPH) were proved in the comparison to ascorbic acid. Xanthones have similar antioxidative capacity against •OH generation in metal involving Fenton reaction, when compared to synthetic analog of vitamin E - Trolox. Neither Trolox nor xanthones showed any sig-nificant capacity to scavenge •OH radical generated in Haber-Weiss-like metal-free generating system indicating their antioxidative action preferentially via sequestration of transition metals preventing •OH generation. According to its antioxidant properties, xanthones were offered as daily supplement (15 lM water solution) to an animal insect model - bean weevil Acantoscelides obtectus. Bean weevil adults have nutritional reserves for the whole lifespan and they only soak water. Treatment did not change endogenous antioxidant level in weevils, but influence the rate of aging. In females, norswertianin-8-O-primeveroside in early age slows down the rate of aging, but accelerates in the late. In males, norswertianin-1-O-primeveroside showed light, but continuous effect on slowing down the rate of aging resulting that supplemented individuals lived longer. The results showed that potential health bene-fits of exogenous nutritional antioxidants are combination of its individ-ual antioxidant properties, composition, amount, metabolic fate, and the influence on antioxidant and other physiological processes, not antioxi-dant activity per se.