Curcumin alleviates imiquimod‐induced psoriasis‐like inflammation and regulates gut microbiota of mice

BACKGROUND: As a polyphenolic compound originated from the food spice turmeric, curcumin (CUR) has various pharmacological effects, such as anti‐inflammatory, antioxidation, antiproliferative, and antiangiogenic activities. Psoriasis is centered on the overproduction of Th1‐ and Th2‐related cytokines (e.g., interleukin [IL]‐23, IL‐17, TNF‐α, IL‐22), which is involved in the occurrence and development of its pathogenesis. However, whether CUR is involved in the treatment of psoriasis and its specific mechanisms are not fully understood. METHODS: In this study, we detected the therapeutic effect of CUR (100 mg/kg/day) on IMQ‐induced dermatitis in mice, analyzed by PASI scores, ELISA, HE staining, immunofluorescence. Moreover, we further confirmed the alteration in the relative abundance of the gut microbiota through 16sRNA to explore whether CUR could regulate the gut microbiota of IMQ‐induced mice. RESULT: Through intragastric administration, CUR can alleviate psoriasis‐like lesions of mice by decreasing PASI scores, reducing the level of IL‐6, IL‐17A, IL‐22, IL‐23, TNF‐α, and TGF‐β1, promoting the expression of IL‐10. Moreover, 16sRNA sequencing revealed that CUR could regulate the alteration in the abundance alteration of gut microbiota related to inflammation, such as Alistipes, Mucispirillum, and Rikenella at genus level. The correlation analysis further confirmed the close association between important microflora and psoriasis‐like inflammation indicators. CONCLUSIONS: CUR exerts the effect of alleviating dermatitis of psoriatic mice by regulating Th‐17 related inflammatory factors. Moreover, the changes in gut microbiota via CUR may be another factor of relieving IMQ‐induced lesions in mice. Therefore, CUR may be a highly promising candidate for the treatment of psoriasis.