<i>Poria cocos</i> Polysaccharide Delays Aging by Enhancing the Antioxidant Ability and Suppressing the Expression of the Branched-Chain Amino Acid Transferase-Encoding Gene in <i>Drosophila melanogaster</i>

<i>Poria cocos</i> polysaccharides (PCP), the main component of <i>Poria cocos</i>, possess a variety of biological activities, including antitumor, immunomodulatory, and antioxidant effects. However, whether PCP has an antiaging effect remains unclear. Here, we studied the beneficial effects and the mechanism of PCP on delaying aging using the <i>Drosophila</i> model. The results showed that the dietary supplementation of PCP significantly extended the lifespan, improved the climbing ability, attenuated intestinal barrier dysfunction, alleviated gastrointestinal acid-base imbalance, and prevented intestinal stem cells (ISCs) hyperproliferation. In addition, PCP notably increased the activities of SOD and CAT and reduced the content of MDA. Furthermore, RNA-Seq showed that PCP supplementation led to the differential expression of 638 genes. KEGG analysis revealed that these differentially expressed genes were strongly enriched in the signaling pathway of cofactor biosynthesis. Among these genes, the expression of the branched-chain amino acid transferase-encoding gene (<i>bcat</i>) was significantly downregulated. The <i>bcat</i>-knockdown prolonged the flies' lifespan, while <i>bcat</i>-overexpression reduced the lifespan. Interestingly, PCP addition can rescue the flies' lifespan in the background of <i>bcat</i>-overexpression. Taken together, our data indicate that PCP delays aging by enhancing the antioxidant ability and suppressing the expression of the <i>bcat</i> gene in <i>Drosophila</i>.