Influence of α-lipoic acid on longevity and stress resistance in Drosophila melanogaster fed with a high-fat diet

Consumption of a high-fat diet is accompanied by the risks of obesity and early onset of age-associated complications for which dietary interventions are imperative to combat. alpha-lipoic acid has been shown to hinder diet-induced obesity and induce lifespan-extending efficacy in model organisms. In this study, alpha-lipoic acid was investigated for its efficacy in improving lifespan and stress resistance in the Canton-S strain of Drosophila melanogaster fed with a high-fat diet. Furthermore, as mating status significantly impacts survival in fruit flies, flies were reared in two experimental groups-group one, in which males and females were bred together, and group two, in which males and females were bred separately. In group one, alpha-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 2-2.5 mM, respectively. In group two, alpha-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 1-2.5 mM, respectively. Improved climbing efficiency was observed with alpha-lipoic acid at the dose range of 1.5-2.5 mM in flies of group one and 1-2.5 mM in flies of group two, respectively. Administration of alpha-lipoic acid improved resistance to oxidative stress in only female flies of group one at 2.5 mM, whereas in group two, both male and female flies exhibited enhanced resistance to oxidative stress with alpha-lipoic acid at a dose range of 2-2.5 mM, respectively. Male and female flies of only group one showed improved resistance to heat shock stress with alpha-lipoic acid at a dose range of 2-2.5 mM. Only female flies of group two exhibited a slight improvement in recovery time following cold shock with alpha-lipoic acid only at 2.5 mM. No significant change in resistance to starvation stress was observed with any dose of alpha-lipoic acid in either group of flies. To summarize, data from this study suggested a probable dose and gender-dependent efficacy of alpha-lipoic acid in flies fed with a high-fat diet, which was significantly influenced by the mating status of flies due to varied rearing conditions.