Effects of Orange Extracts on Longevity, Healthspan, and Stress Resistance in Caenorhabditis elegans

Orange, with various bioactive phytochemicals, exerts various beneficial health effects, including anti-cancer, antioxidant, and anti-inflammatory properties. However, its anti-aging effects remain unclear. In this study, the Caenorhabditis elegans (C. elegans) model was used to evaluate the effects of orange extracts on lifespan and stress resistance. The results indicated that orange extracts dose-dependently increased the mean lifespan of C. elegans by 10.5%, 18.0%, and 26.2% at the concentrations of 100, 200, and 400 mg/mL, respectively. Meanwhile, orange extracts promoted the healthspan by improving motility, and decreasing the accumulation of age pigment and intracellular reactive oxygen species (ROS) levels without damaging fertility. The survival rates of orange extract-fed worms were obviously higher than those of untreated worms against thermal and ultraviolet-B (UV-B) stress. Moreover, the activities of superoxide dismutase (SOD) and catalase (CAT) were significantly enhanced while malondialdehyde (MDA) contents were diminished. Further investigation revealed that worms supplemented with orange extracts resulted in upregulated levels of genes, including daf-16, sod-3, gst-4, sek-1, and skn-1, and the downregulation of age-1 expression. These findings revealed that orange extracts have potential anti-aging effects through extending the lifespan, enhancing stress resistance, and promoting the healthspan.