Aqueous extract of Acer truncatum leaves retards Drosophila melanogaster senescence by regulating amino acid metabolism and gut microbiota

Acer truncatum is a unique tree species indigenous to northern China. The Chinese government approved the utilization of Acer truncatum leaves as a raw material for food. These leaves have been traditionally used in Inner Mongolia as a form of anti-aging medicine. However, the specific mechanism responsible for the anti-aging properties of Acer truncatum leaves remains unidentified. In this study, an aqueous extract of Acer truncatum leaves (AAL) was prepared and analyzed using UPLC-QTOF-MS/MS. the UPLC-MS/MS profile detected a total of 989 compounds in AAL, with 5 compounds of high concentration selected for quantitative analysis via UPLC-QTOF-MS/MS employing the internal standard method. Subsequently, Drosophila melanogaster served as a model organism to assess the impact of AAL on the lifespan and locomotor abilities. The results demonstrated a significant extension of the lifespan of D. melanogaster in response to AAL supplementation. Moreover, the addition of AAL to the medium enhanced the physical and anti-stress abilities of D. melanogaster, while preserving the integrity of their intestinal barrier. Gut microbiome analysis revealed that AAL administration positively influenced the structure and composition of gut microbes in aged D. melanogaster, notably reducing the prevalence of detrimental bacteria like Enterococcus and increasing beneficial bacteria such as Lactococcus. Metabolomic analysis annotated 30 potentially significant metabolites in AAL that contribute to delaying aging, predominantly associated with Phenylalanine metabolic pathways. Through a comprehensive multi-omics correlation analysis, a strong link was established between gut microbiota and metabolites following AAL treatment, highlighting how AAL prolongs the lifespan of D. melanogaster by modulating metabolic pathways via the gut microbiota. This study offers valuable insights into the anti-aging properties of AAL, emphasizing its ability to delay aging primarily through the regulation of metabolic pathways mediated by the gut microbiota and sets a foundation for the potential future application of AAL as a functional food.