Methionine-induced alterations in the life span, antioxidant enzymes, and peroxide levels in aging Zaprionus paravittiger (Diptera).

The median and maximum life spans of both sexes of Zaprionus paravittiger increased with methionine (100 mM) feeding. It was accompanied by higher catalase and peroxidase enzyme activities. The lipid peroxide level as measured by malondialdehyde content and the inorganic peroxides showed an increase with age and a decrease in methionine-fed insects. The reduction was, however, more pronounced in females than in males. The findings indicate that a life-prolonging effect of methionine on Z. paravittiger may be by virtue of its free radical scavenging effect.