Chili pepper extends lifespan in a concentration-dependent manner and confers cold resistance on Drosophila melanogaster cohorts by influencing specific metabolic pathways

Piperine improves the health span of Drosophila melanogaster with age- and sex-specific effect

Piperine, a dietary phytochemical isolated from the Piper species, has been used as a natural medicine for pain, flu, and fever in ancient China and India. Although the health benefits of piperine have been widely studied, research on its effect on aging is limited. This study aimed to determine whether piperine has the potential to mitigate aging-related changes in the fruit fly (Drosophila melanogaster), which is an excellent model organism for studies on aging. The experiments were conducted using the newly eclosed or 30-day-old D. melanogaster wild-type strain Cantonized-white. Piperine was dissolved in 99% ethanol and added to the sucrose-yeast medium at a final concentration of 10, 35, 70, or 100 μM. The study examined the effects of piperine supplementation on the lifespan of D. melanogaster and other physiological functions, such as fecundity, feeding, lipid content, and resistance to environmental stress. Log-rank tests, Shapiro-Wilk test, F-test, t-test, or Wilcoxon rank sum test were used to analyze the data. Piperine failed to change the lifespan and body weight, but increased the fecundity and decreased the feeding rate in one-week-old flies. However, when piperine was fed to 30-day-old flies, it increased the lifespan of male flies and the fecundity and feeding rate of female flies. These results indicate that piperine can improve the health of aged flies. The findings suggest that piperine has age-dependent and sex-specific anti-aging effects in fruit flies.

Alpha-ketoglutarate supplementation in long-lived Drosophila melanogaster: Impact on lifespan and metabolic responses

Studies on antiaging remedies in insect models sometimes show discrepancies in results. These discrepancies could be explained by different responses of short- and long-lived strains on the antiaging remedies. The purpose of the study was to test whether life-prolonging effects of alpha-ketoglutarate (AKG), observed in nematodes and fruit flies, would be reproduced in long-lived Drosophila melanogaster flies. Lifespan was assayed in flies kept in demographic cages. Fecundity, proportion of flies capable of negative geotaxis, starvation resistance, time of heat coma onset, levels of triacyglycerols, body glucose, glycogen, activities of glutamate dehydrogenase, catalase, glutathione-S-transferase, hexokinase, phosphofructokinase, pyruvate kinase, lactate, and glutamate dehydrogenases were assessed. Dietary AKG did not affect fly lifespan on the diet with 5% yeast and 5% sucrose (5Y:5S) and on the diet with 9% yeast and 1% sucrose (9Y:1S), but increased lifespan on the low-protein diet (1Y:9S). Twenty-five-day-old female flies fed a 5Y:5S diet with 10 mM AKG for 3 weeks, did not differ from the control group (without AKG) in climbing activity, resistance to heat stress, and starvation. The levels of glucose and glycogen were unaffected but the levels of triacylglycerols were lower in AKG-fed female flies. No differences in activities of glycolytic enzymes, NADPH-producing enzymes, glutamate dehydrogenase, oxygen consumption, and levels of oxidative stress markers were observed between the control and AKG-fed flies. However, AKG-fed flies had lower activities of catalase and glutathione-S-transferase. These results suggest that potential antiaging remedies, such as AKG, may not extend lifespan in long-living organisms despite influencing several metabolic parameters.

Gender-specific effects of pro-longevity interventions in Drosophila

Sex differences in lifespan are well recognized in the majority of animal species. For example, in male versus female Drosophila melanogaster there are significant differences in behavior and physiology. However, little is known about the underlying mechanisms of gender differences in responses to pro-longevity interventions in this model organism. Here we summarize the existing data on the effects of nutritional and pharmacological anti-aging interventions such as nutrition regimens, diet and dietary supplementation on the lifespan of male and female Drosophila. We demonstrate that males and females have different sensitivities to interventions and that the effects are highly dependent on genetic background, mating, dose and exposure duration. Our work highlights the importance of understanding the mechanisms that underlie the gender-specific effect of anti-aging manipulations. This will provide insight into how these benefits may be valuable for elucidating the primary physiological and molecular targets involved in aging and lifespan determination.

Chili-supplemented food decreases glutathione-S-transferase activity in Drosophila melanogaster females without a change in other parameters of antioxidant system

OBJECTIVES

Many plant-derived anti-aging preparations influence antioxidant defense system. Consumption of food supplemented with chili pepper powder was found to extend lifespan in the fruit fly, Drosophila melanogaster. The present study aimed to test a connection between life-extending effect of chili powder and antioxidant defense system of D. melanogaster.

METHODS

Flies were reared for 15 days in the mortality cages on food with 0% (control), 0.04%, 0.12%, 0.4%, or 3% chili powder. Antioxidant and related enzymes, as well as oxidative stress indices were measured.

RESULTS

Female flies that consumed chili-supplemented food had a 40-60% lower glutathione-S-transferase (GST) activity as compared with the control cohort. Activity of superoxide dismutase (SOD) was about 37% higher in males that consumed food with 3% chili powder in comparison with the control cohort. Many of the parameters studied were sex-dependent.

CONCLUSIONS

Consumption of chili-supplemented food extends lifespan in fruit fly cohorts in a concentration- and gender-dependent manner. However, this extension is not mediated by a strengthening of antioxidant defenses. Consumption of chili-supplemented food does not change the specific relationship between antioxidant and related enzymes in D. melanogaster, and does not change the linkage of the activities of these enzymes to fly gender.

Peppers in Diet: Genome-Wide Transcriptome and Metabolome Changes in Drosophila melanogaster

The habanero pepper (Capsicum chinense) is an increasingly important spice and vegetable crop worldwide because of its high capsaicin content and pungent flavor. Diets supplemented with the phytochemicals found in habanero peppers might cause shifts in an organism’s metabolism and gene expression. Thus, understanding how these interactions occur can reveal the potential health effects associated with such changes. We performed transcriptomic and metabolomic analyses of Drosophila melanogaster adult flies reared on a habanero pepper diet. We found 539 genes/59 metabolites that were differentially expressed/accumulated in flies fed a pepper versus control diet. Transcriptome results indicated that olfactory sensitivity and behavioral responses to the pepper diet were mediated by olfactory and nutrient-related genes including gustatory receptors (Gr63a, Gr66a, and Gr89a), odorant receptors (Or23a, Or59a, Or82a, and Orco), and odorant-binding proteins (Obp28a, Obp83a, Obp83b, Obp93a, and Obp99a). Metabolome analysis revealed that campesterol, sitosterol, and sucrose were highly upregulated and azelaic acid, ethyl phosphoric acid, and citric acid were the major metabolites downregulated in response to the habanero pepper diet. Further investigation by integration analysis between transcriptome and metabolome data at gene pathway levels revealed six unique enriched pathways, including phenylalanine metabolism; insect hormone biosynthesis; pyrimidine metabolism; glyoxylate, and dicarboxylate metabolism; glycine, serine, threonine metabolism; and glycerolipid metabolism. In view of the transcriptome and metabolome findings, our comprehensive analysis of the response to a pepper diet in Drosophila have implications for exploring the molecular mechanism of pepper consumption.