The Water Extract of Sweet Tea Alleviates LPS-Induced Acute Lung Injury Through Anti-Inflammatory and Antioxidant Effects

<b>Background/Objectives:</b><i>Lithocarpus litseifolius</i> (Hance) Chun, also known as sweet tea, is a traditional Chinese tea-making plant. Acute lung injury (ALI), a life-threatening syndrome with symptoms like hypoxemia and dyspnea, can be triggered by infection or trauma, with high morbidity and mortality. Whether the water extract of <i>Lithocarpus litseifolius</i> (WEL) has therapeutic effects on ALI remains unclear. This study aimed to analyze WEL's components, establish in vitro cellular inflammation and mouse ALI models, and investigate WEL's protective effects against LPS-induced ALI. <b>Methods:</b> LC-MS analysis identified 42 compounds in WEL and quantified three key ones. In an LPS-induced mouse ALI model, WEL significantly reduced lung injury severity, lung wet-to-dry ratio, pulmonary edema, and levels of NO, ROS, IL-1β, TNF-α, and MPO in lung tissues and bronchial alveolar lavage fluid. Immunohistochemical analysis showed WEL pretreatment inhibited the upregulation of NLRP3, Caspase-1, and GSDMD-NT expression, mitigated tissue oxidative stress and cell pyroptosis, and alleviated ALI severity in mice. Cellular experiments confirmed WEL's protective effects via anti-inflammatory, antioxidant actions, and inhibiting cell pyroptosis, with phlorizin and trilobatin as potential key active ingredients. <b>Conclusions:</b> This research demonstrates sweet tea's significant protective effects against ALI and its potential to alleviate inflammation by inhibiting pyroptosis, providing a theoretical basis for developing new health-promoting functions of sweet tea.