Lifespan-extending and stress resistance properties of brazilin from Caesalpinia sappan in Caenorhabditis elegans

This study contributes to the continual discovery of lifespan-extending compounds from plants, using the Caenorhabditis elegans model system. An ethyl acetate soluble fraction of methanol extract from the heartwood of Caesalpinia sappan showed a significant lifespan-extending activity. Subsequent activity-guided chromatography of the ethyl acetate-soluble fraction led to the isolation of brazilin. Brazilin showed potent 2,2-diphenyl-1-picrylhydrazyl radical scavenging and superoxide anion quenching activities and also revealed a lifespan-extending activity in C. elegans under normal culture conditions. Brazilin also exhibited the protective effects against thermal, oxidative and osmotic stress conditions to improve the survival rate of the nematode. Furthermore, brazilin elevated superoxide dismutase (SOD) activity and decreased intracellular reactive oxygen species accumulation in C. elegans. Further studies showed that brazilin-mediated increased stress tolerance of worms could be due to increased expressions of stress resistance proteins such as heat shock protein (HSP-16.2) and superoxide dismutase (SOD-3). Besides, there were no significant, brazilin-induced changes in aging-related factors, including progeny production, food intake, and growth, indicating brazilin influences longevity activity independent of affecting these factors. Brazilin increased the body movement of aged worms, indicating brazilin affects the healthspan and lifespan of nematode. These results suggest that brazilin contributes to the lifespan of C. elegans under both normal and stress conditions by increasing the expressions of stress resistance proteins.