Antioxidant and anti-aging effects of polysaccharide LDP-1 from wild <em>Lactarius deliciosus</em> on <em>Caenorhabditis elegans</em>

Background: Edible fungi (mushrooms) have attracted much more concerns due to their abundant nutritions and functional bioactive substances like polysaccharides. Objective: In this study, the anti-oxidation and anti-aging activities of polysaccharide fraction (LDP-1) from the wild Lactarius deliciosus fruiting bodies were systematically evaluated using Caenorhabditis elegans (C. elegans) as a model. Methods: Lifetime determination of C. elegans (survival status) was observed via microscope. Effects of LDP-1 on C. elegans induced by heat and oxidative stress were, respectively, performed in an artificial climate chamber and Juglone solution. Determination of lipofuscin levels in C. elegans was observed by laser confocal scanning microscopy. Determination of reactive oxygen species in C. elegans in vivo was conducted via fluorescence spectrophotometer reader. Results: The results revealed that LDP-1 could significantly extend the lifespan of C. elegans, and the lifetime of C. elegans treated with 1,000 μg/mL LDP-1 could be prolonged by 32.8% compared with the control. The survival rates of the experimental C. elegans under heat shock and oxidative stress conditions were clearly improved after treated with 1,000 μg/mL LDP-1 (40 and 19.8%, respectively), while under the same circumstances all the C. elegans in the blank group died. Fluorescence microscopy analysis confirmed that LDP-1 could effectively reduce the accumulation of lipofuscin and reactive oxygen free radicals in C. elegans, where the respective maximum reduction reached 22.8 and 42.7% compared with the control. Conclusion: These results indicate that LDP-1 had favorable antioxidant and anti-aging effects, which could be explored as potential dietary additives to renovate oxidative damage and slow down aging process.