Zinc pyrithione ameliorates colitis in mice by interacting on intestinal epithelial TRPA1 and TRPV4 channels

Although zinc pyrithione (ZPT) has been studied as topical antimicrobial and cosmetic consumer products, little is known about its pharmacological actions in gastrointestinal (GI) health and inflammation. Our aims were to investigate the effects of ZPT on transient receptor potential (TRP) channels and Ca²⁺ signaling in intestinal epithelial cells (IECs) and its therapeutic potential for colitis.

Digital Ca²⁺ imaging and patch-clamp electrophysiology were performed on human colonic epithelial cells (HCoEpiC) and rat small intestinal epithelial cells (IEC-6). The transcription levels of proinflammatory cytokines such as IL-1β were detected by RTq-PCR. Dextran sulfate sodium (DSS) was used to induce colitis in mice.

ZPT dose-dependently induced Ca²⁺ signaling and membrane currents in IECs, which were attenuated by selective blockers of transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential vanilloid 4 (TRPV4) channels, respectively. Interestingly, Ca²⁺ entry via TRPA1 channels inhibited the activity of TRPV4 channels in HCoEpiC, but not vice versa. ZPT significantly promoted migration of IECs by activating TRPA1 and TRPV4 channels. ZPT reversed lipopolysaccharides (LPS)-induced changes in mRNA expression of TRPA1 and TRPV4. Moreover, ZPT decreased mRNA levels of pro-inflammatory factors promoted by LPS in HCoEpiC, which were restored by selective TRPA1 blocker. In whole animal studies in vivo, ZPT significantly ameliorated DSS-induced body weight loss, colon shortening and increases in stool score, serum calprotectin and lactic acid (LD) in mouse model of colitis.

ZPT exerts anti-colitic action likely by anti-inflammation and pro-mucosal healing through TRP channels in IECs. The present study not only expands pharmacology spectrum of ZPT in GI tract, but also repurposes it to a potential drug for colitis therapy.