Rearing conditions impacted efficacy of α-lipoic acid to influence longevity in Drosophila melanogaster fed with a high fat diet

Abstract

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