Antioxidant Activity and DAF-16-Associated Lifespan-Promoting Effects of Essential Oil from <i>Melastoma sanguineum</i> Sims in <i>Caenorhabditis elegans</i>.

<i>Melastoma sanguineum</i> Sims is a traditional medicinal plant with edible fruits, but little is known about the biological activities of its essential oil. In this study, <i>Caenorhabditis elegans</i> was used as an animal model to investigate the antioxidant and lifespan-promoting effects of <i>M. sanguineum</i> essential oil, designated EO-2141. EO-2141 showed in vitro antioxidant activity. In <i>C. elegans</i>, EO-2141 significantly extended mean lifespan and reduced lipofuscin accumulation. It also enhanced resistance to oxidative and thermal stress and reduced DCF fluorescence. In addition, EO-2141 reduced MDA levels and increased SOD and GSH-PX activities. Gene-expression analysis showed that EO-2141 upregulated <i>daf-16</i> and the stress-responsive genes <i>sod-3</i>, <i>ctl-2</i>, and <i>hsp-16.2</i>, while reducing <i>akt-1</i> expression. DAF-16::GFP analysis further showed that EO-2141 increased the proportion of worms exhibiting nuclear DAF-16 localization. Moreover, EO-2141 failed to produce a significant lifespan extension in <i>daf-16(mgDf50)</i> mutants, further implicating DAF-16 in the longevity response to EO-2141. These findings demonstrate the antioxidant and lifespan-promoting effects of EO-2141 in <i>C. elegans</i> and provide transcriptional, subcellular-localization, and genetic evidence supporting the involvement of DAF-16 in its longevity response.