Immunomodulatory Effects of Oolong Tea Phytochemicals on NLRP3 Inflammasome Priming and Activation via Scavenging ROS in LPS-stimulated Macrophages

This study investigated the anti-inflammatory effects of oolong tea (OLT) extracts, specifically targeting their modulation of the NLRP3 inflammasome pathway, a key player in chronic inflammatory diseases. OLT extracts were prepared from the Jin-Xuan cultivar using hot water extraction, and their bioactive compo-nents—including total phenolics, flavonoids, catechins (EGCG and EGC), and con-densed tannins—were quantified. Using lipopolysaccharide (LPS)-stimulated J774A.1 macrophages, the anti-inflammatory potential of OLT extracts was assessed by meas-uring cytokine secretion (IL-1β, IL-6, TNF-α), caspase-1 activation, ASC oligomeriza-tion, and intracellular ROS levels via ELISA, Western blot, and fluorescence microsco-py. The results showed that OLT extracts, particularly at 100 µg/mL, significantly sup-pressed both the priming and activation phases of NLRP3 inflammasome formation, inhibited IL-1β secretion by over 50%, and reduced intracellular ROS levels by 50%. These findings suggest that OLT extracts exert potent anti-NLRP3 inflammasome ac-tivity and offer immunomodulation potential in preventing inflammation-related dis-eases such as infections, cancer, and neurodegenerative disorders. Further clinical ap-plications and epidemiological studies are warranted to validate these preventive ef-fects in human populations.