Plant Polysaccharides Regulated Stress Tolerance and Lifespan in Caenorhabditis elegans through DAF-16 Activation
學生姓名:
蘇歆惠
指導教授:
陳詠宗
學 期:
113下
摘 要:
The global issue of population aging is becoming increasingly severe and is now a focus of international concern. Oxidative stress is recognized as one of the primary factors driving the aging process. Continuous oxidative damage leads to cellular dysfunction, promoting age-related diseases such as neurodegenerative disorders and cardiovascular diseases. Among natural antioxidants, plant-derived polysaccharides have attracted considerable interest due to their antioxidant, anti-inflammatory, and potential anti-aging properties. This study employed Caenorhabditis elegans as a model organism to investigate the anti-aging effects and underlying mechanisms of polysaccharides extracted from Lonicera japonica and Polygonatum cyrtonema. Both Lonicera japonica polysaccharides (CLJP) and Polygonatum cyrtonema polysaccharides (PCP) significantly extended the lifespan of C. elegans, likely through modulation of the insulin/IGF-1 signaling (IIS) pathway. This regulation promoted the nuclear translocation of the transcription factor DAF-16, leading to the upregulation of antioxidant and stress resistance genes (sod-3, gst-4, hsp-16.2, skn-1). Furthermore, the antioxidant potential of these polysaccharides was validated through both in vivo and in vitro assays. Both CLJP and PCP significantly enhanced SOD and CAT activities in C. elegans, while reducing the MDA. In vitro, PCP exhibited strong radical-scavenging abilities, as demonstrated by its performance in DPPH and ABTS+ assays, effectively decreasing ROS production and mitigating oxidative damage. Notably, the purified fraction PCP (PCP-1) displayed superior efficacy in enhancing antioxidant enzyme activities and alleviating oxidative stress compared to crude PCP, suggesting its potential as a more potent bioactive anti34 aging compound. In summary, CLJP and PCP promote longevity and stress resistance by negatively regulating the IIS pathway, thereby reducing oxidative and thermal stress. These effects ultimately contribute to lifespan extension and healthy aging. These results highlight the potential of CLJP and PCP as natural functional ingredients for developing anti-aging nutraceuticals or pharmaceuticals.
蘇歆惠.pdf