Extraction Optimization and Bioactivity of Polysaccharides from Ganoderma leucocontextum Spores

<b>Background:</b> Oxidative stress is associated with the occurrence and progress of aging. Natural polysaccharides have attracted considerable attention in the field of antioxidants and anti-aging products due to their superior biological activity and low toxicity. Ga<i>noderma leucocontextum</i> is primarily found in the Tibetan plateau region and is classified as a subspecies of <i>Ganoderma</i>. Known as the famous white <i>Ganoderma</i>, it is a precious food and medicine that has potent biological activity, including antitumor, hypoglycemic, and immune regulation. Since available resources are limited, there are few studies on the spore of <i>Ganoderma leucocontextum</i>. <b>Methods:</b> In this work, a polysaccharide (named GLSP) was extracted from the spore of <i>Ganoderma leucocontextum</i> using a fast, simple, efficient, and environmentally friendly extraction process: the three-phase partitioning (TPP) method. <b>Results:</b> The extraction condition was optimized under the Box-Behnken design (BBD): ratio of the solute to the solvent, 1:21.126 (<i>w</i>/<i>v</i>); (NH₄)₂SO₄ concentration, 30% (<i>w</i>/<i>v</i>); ratio of the slurry to tert-butanol, 1:1.945 (<i>v</i>/<i>v</i>); and shaking temperature, 54.136 °C. Furthermore, a polysaccharide termed GLSP-A1 was purified from GLSP by column chromatography. The basic physicochemical properties were analyzed by molecular weight, Fourier transform infrared spectroscopy, monosaccharide composition, and scanning electron microscopy. <b>Conclusions:</b> GLSP-A1 down-regulated the expression of the pro-inflammation cytokines interleukin-6 and interleukin-1β, indicating favorable in vitro anti-inflammatory properties. In vivo, the effect of GLSP-A1 on aging was examined using the Caenorhabditis model. The results showed that GLSP-A1 reduced reactive oxygen species levels and lipofuscin accumulation. In general, these findings improve our understanding of the chemical content and bioactivity of a polysaccharide from <i>Ganoderma leucocontextum</i> spore and highlight the possibility of GLSP-A1 being utilized in dietary supplements for its anti-aging properties.