Characterization and Anti-Aging Potency of Phenolic Compounds in Xianhu Tea Extracts

The health benefits of tea are primarily attributed to its chemical composition, particularly phenolic compounds. As a renowned tea from Guangdong, China, Xianhu tea (XHT) has not been thoroughly studied in terms of its phenolic composition or health-promoting properties. This study characterized the phenolic compounds in Xianhu tea water extract (XHT) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and evaluated its antioxidant activity in vitro. Furthermore, the effects of XHT extracts on reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), lipofuscin levels, and lifespan in <i>Caenorhabditis elegans</i> were assessed, alongside their modulation of aging-related genes. Compared with Xinyang Maojian tea water extract (XYMJ) and Yingde black tea water extract (YDBT), XHT exhibited a significantly higher polyphenol content, with 23 phenolic compounds identified as characteristic markers. XHT demonstrated superior 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) inhibition capacities, the greatest reductions in ROS, MDA, and lipofuscin levels, and the highest upregulation of SOD and CAT activities. The lifespan was 23.50% and 21.07% significantly longer than nematodes in the control group. Moreover, XHT modulated 13 aging-related genes, which strongly correlated with the 23 identified phenolic compounds. The research results of the above indicators were all obtained without affecting the normal feeding and reproductive capabilities of <i>C. elegans</i>. These findings suggest that these phenolics are the key bioactive components responsible for the anti-aging effects of XHT.