Effect and mechanism of hydrogen‐rich bath on mice with imiquimod‐induced psoriasis

Abstract The purpose of this study was to investigate whether hydrogen‐rich bath has therapeutic effect on psoriasis and its molecular mechanism. Mice with imiquimod‐induced psoriasis were established and divided into groups. The mice were respectively treated with hydrogen‐rich water bath and distilled water bath. The changes of skin lesions and PSI scores of mice were compared after their treatments. HE staining was used to observe the pathological feature. The changes of inflammatory indexes and immune factors were analysed by ELISA and immunohistochemical staining. Malondialdehyde (MDA) content was measured by the thiobarbituric assay (TBA) method. By naked eye, the severity of skin lesions in hydrogen‐rich water bath group was lower than that in distilled water bath group, and the psoriasis severity index (PSI) was lower ( p < 0.01). The results of HE staining showed that the mice with distilled water bath had more abnormal keratosis, thickening of the spinous layer and prolongation of the dermal process, and more Munro abscess than the mice with hydrogen‐rich water bath. During the course of disease, the overall levels and peaks of IL‐17, IL‐23, TNF‐α, CD3 + and MDA in mice with hydrogen‐rich bath were lower than those in mice with distilled water bath ( p < 0.05). In the skin, the mice treated with the hydrogen‐rich water bath also had lower peak of proliferating cell nuclear antigen (PCNA) levels. It is concluded that hydrogen‐rich water bath can inhibit psoriasis inflammation and oxidative stress, relieve psoriasis skin lesions and accelerate the end of abnormal skin proliferation state, which shows a therapeutic and improving effect on psoriasis.