Anti‐Inflammatory and Antioxidant Activities of Polyphenols From Loquat ( <i>Eriobotrya japonica</i> Lindl.) Leaf Hair in Lipopolysaccharide‐Induced In Vitro and In Vivo Models

ABSTRACT This study aimed to characterize polyphenols present in Loquat ( Eriobotrya japonica Lindl.) leaf hair (LLH) and evaluate their antioxidant and anti‐inflammatory effects in lipopolysaccharide (LPS)‐induced inflammation models In Vitro and In Vivo. Ultra‐performance liquid chromatography coupled with UPLC‐HRMS identified 24 compounds in LLH, including 21 polyphenols, notably revealing the presence of four polymethoxyflavones previously unreported in loquat. Antioxidant evaluations (ABTS, DPPH, FRAP, and ORAC) confirmed robust radical‐scavenging and reducing capabilities of LLH extract. In Vitro studies utilizing human liver L02 cells demonstrated that LLH significantly suppressed LPS‐induced reactive oxygen species (ROS) generation, preserved antioxidant enzyme activities (CAT, SOD, and GSH‐Px), and upregulated antioxidant‐related genes ( Nrf2 , Cat , Sod1 , and Gpx1 ). Furthermore, LLH pretreatment markedly inhibited LPS‐induced nitric oxide (NO) release, inflammatory cytokine (IL‐1β, IL‐6, and TNF‐α) production, and downregulated the Jak2–Stat3 inflammatory signaling pathway. Consistently, In Vivo experiments using an LPS‐induced acute liver injury mouse model revealed that oral administration of LLH significantly reduced hepatic oxidative stress and inflammation by restoring antioxidant enzyme activities, enhancing Nrf2 ‐mediated antioxidant pathways, and suppressing inflammatory mediators and Jak2–Stat3 signaling in liver. Collectively, these findings demonstrate LLH polyphenols' potent antioxidant and anti‐inflammatory effects and suggest their potential as natural functional agents for managing inflammation‐related oxidative stress.