Potential Therapeutic Effects of Oolong Tea Phytochemicals on NLRP3 Inflammasome Assembly and Oxidative Stress

Tea, the world's second most consumed beverage after water, contains diverse phytochemicals that have garnered growing interest for their potential ability to modulate inflammasome activation. This study examined the antioxidant and anti-inflammatory properties of oolong tea (OLT) extracts, with a specific focus on their regulatory effects on NLRP3 inflammasome assembly-a critical mediator in chronic inflammatory diseases.

OLT extracts were prepared from the Jin-Xuan cultivar with quantification for bioactive components (total phenolics, flavonoids, condensed tannins, and proanthocyanidins). J774A.1 murine macrophages were primed with LPS and stimulated with ATP to induce inflammasome activation. Therapeutic potentials of OLT extracts were assessed by measuring cytokine secretion, expression of NLRP3 inflammasome-related proteins (NLRP3, ASC, Caspase-1, and IL-1β), inflammasome complex formation, and ROS generation via biochemical assays, immunoblotting, and fluorescence microscopy.

OLT extracts, particularly at 100 µg/mL, markedly suppressed both the priming and activation phases of NLRP3 inflammasome formation. OLT treatment reduced IL-1β secretion by more than 50%, attenuated ASC oligomerization and speck formation, inhibited caspase-1 cleavage, and lowered intracellular ROS levels by approximately 50%.

These findings suggest that OLT extracts exert potent anti-NLRP3 inflammasome activity and offer immunomodulation potential in preventing inflammation-related diseases such as infections, cancer, and neurodegenerative disorders. Further in vivo investigations, followed by clinical applications and epidemiological studies, are warranted to validate these preventive effects in human populations.