Antioxidants prolong life span and inhibit the senescence- dependent accumulation of fluorescent pigment (lipofuscin) in clones of Podospora anserina

Abstract

Culture of clones of Podospora anserina s + with either nordihydroguaiaretic acid or reduced glutathione (GSH) at concentrations that were not inhibitory to growth significantly prolonged the average time to onset of senescence. GSH also prolonged the average time to onset of clonal death. The specific concentration of chloroform-methanol soluble fluorescent pigment was larger in senescent than in pre-senescent cells. The pigment exhibited fluorescence excitation and emission spectra and fluorescence polarization numbers characteristic of lipofuscin, an end-product of lipid peroxidation. Analyses of the lipofuscin concentration in either sub-clonal fractions of different times of origin from senescent clones, or in sub-clonal fractions of identical age in time of origin from parent clones of different age, revealed a similar concentration distribution. Although pre-senescent cells contained rather large concentrations, a massive increase occured during senescence prior to the time of onset of clonal death. Culture with GSH not only prolonged clonal life span but also inhibited the formation of lipofuscin by an average factor of 30. Furthermore, unlike untreated clones, the sub-clonal distribution of the pigment was not only low but was also independent of their age.