Selenocysteine modulates resistance to environmental stress and confers anti-aging effects in C. elegans

OBJECTIVE: The free radical theory of aging suggests that cellular oxidative damage caused by free radicals is a leading cause of aging. In the present study, we examined the effects of a well-known anti-oxidant amino acid derivative, selenocysteine, in response to environmental stress and aging using Caenorhabditis elegans as a model system. METHOD: The response to oxidative stress induced by H2O2 or ultraviolet irradiation was compared between the untreated control and selenocysteine-treated groups. The effect of selenocysteine on lifespan and fertility was then determined. To examine the effect of selenocysteine on muscle aging, we monitored the change in motility with aging in both the untreated control and selenocysteine-treated groups. RESULTS: Dietary supplementation with selenocysteine significantly increased resistance to oxidative stress. Survival after ultraviolet irradiation was also increased by supplementation with selenocysteine. Treatment with selenocysteine confers a longevity phenotype without an accompanying reduction in fertility, which is frequently observed in lifespan-extending interventions as a trade-off in C. elegans. In addition, the age-related decline in motility was significantly delayed by supplementation of selenocysteine. CONCLUSION: These findings suggest that dietary supplementation of selenocysteine can modulate response to stressors and lead to lifespan extension, thus supporting the free radical theory of aging.

Supplementation of S-allyl cysteine improves health span in Caenorhabditis elegans / A suplementação de S-alil cisteína melhora a duração da saúde em Caenorhabditis elegans

Previous studies show that nutritional interventions with anti-oxidants have various healthpromoting effects in several model organisms. Here, we examine the effects of S-allyl cysteine on resistance to environmental stressors and age-related physiological changes using C. elegans as a model system. S-allyl cysteine is a modified amino acid found in aged garlic extracts and known to have strong anti-oxidant activity. The survival of worms under oxidative-stress conditions significantly increased with supplementation of S-allyl cysteine. In addition, pretreatment of S-allyl cysteine significantly increased resistance to both heat stress and ultraviolet irradiation. However, lifespan was not affected by S-allyl cysteine treatment. We also examined the effect of S-allyl cysteine on motility of C. elegans and found that S-allyl cysteine can retard the age-related decline of muscle tissue locomotive activity. S-allyl cysteine also significantly suppressed amyloid -induced paralysis in Alzheimer's disease model animals. Taken together, our study indicates that dietary supplementation of S-allyl cysteine can improve health span and suggests that S-allyl cysteine can be used to develop novel health-promoting pharmaceuticals.

Estudos anteriores mostram que intervenções nutricionais com antioxidantes têm vários efeitos promotores da saúde em vários organismos-modelo. Aqui, examinamos os efeitos da S-alil cisteína sobre a resistência a estressores ambientais e alterações fisiológicas relacionadas com a idade usando C. elegans como um sistema modelo. Salil cisteína é um aminoácido modificado encontrado em extratos de alho envelhecido e conhecido por ter forte atividade antioxidante. A sobrevivência de vermes sob condições de estresse oxidativo aumentou significativamente com a suplementação de S-alil cisteína. Além disso, o pré-tratamento com S-alil cisteína aumentou significativamente a resistência tanto ao estresse térmico como à irradiação ultravioleta. No entanto, o tempo de vida não foi afetado pelo tratamento com S-alil cisteína. Nós também examinamos o efeito da S-alil cisteína na motilidade de C. elegans e descobrimos que a S-alil cisteína pode retardar o declínio relacionado à idade da atividade locomotora do tecido muscular. A S-alil cisteína também suprimiu significativamente a paralisia induzida por amilóide em animais-modelo da doença de Alzheimer. Tomados em conjunto, o nosso estudo indica que a suplementação dietética de S-alil cisteína pode melhorar a duração da saúde e sugere que S-alil cisteína pode ser usada para desenvolver novos produtos farmacêuticos de promoção da saúde.