OBJECTIVE: This study aims to elucidate the therapeutic potential of osthole for the treatment of atopic dermatitis (AD), focusing on its ability to alleviate chronic pruritus (CP) and the underlying molecular mechanisms. METHODS: In this study, we investigated the anti-inflammatory effects of osthole in both a 2,4-dichloronitrobenzene (DNCB)-induced AD mouse model and tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) stimulated huma immortalized epidermal (HaCaT) cells. The anti-itch effect of osthole was specifically assessed in the AD mouse model. Using methods such as hematoxylin and eosin (HE) staining, enzyme-linked immunosorbent assay (ELISA), western blot (WB), quantitative real-time PCR (qRT-PCR), and immunofluorescence staining. RESULTS: Osthole improved skin damage and clinical dermatitis scores, reduced scratching bouts, and decreased epidermal thickness AD-like mice. It also reduced the levels of interleukin (IL)-31 and IL-31 receptor A (IL-31 RA) in both skin tissues and HaCaT cells. Furthermore, Osthole suppressed the protein expression levels of phosphor-p65 (p-p65) and phosphor-inhibitor of nuclear factor kappa-Bα (p-IκBα). Meanwhile, it increased the protein expression levels of peroxisome proliferator-activated receptor α (PPARα) and PPARγ in HaCaT cells. CONCLUSION These findings indicated that osthole effectively inhibited CP in AD by activating PPARα, PPARγ, repressing the NF-κB signaling pathway, as well as the expression of IL-31 and IL-31 RA.

This study aims to investigate the effects of Pulsatilla decoction(PD)on the 5-HT sig-naling system in the hippocampus of damp-heat diarrhoea(DHD)rats.Twenty-four male SD rats were randomly divided into four groups including the blank group,the model group,the PD group and the self-healing group.Except for the blank group,the rats in each group were induced by"high sugar and high fat,high temperature and high humidity,and E.coli poisoning"to establish a of rat model DHD,and were treated by gavage with PD.Changes in body weight,temperature,food intake and water intake,routine blood tests and histopathological changes in the colon were recor-ded to comprehensively determine the modelling condition of rats with DHD;histopathological changes in the hippocampus of rats were observed,and real-time fluorescence PCR was used to de-termine the expression of IL-1β3,IL-6,TNF-α,IFN-γ and TPH1 mRNA in the hippocampus;West-ern blot and immunohistochemistry were used to detect the protein expression of tryptophan hydroxylase 1(TPH1),receptors(5-HT3R,5-HT4R,5-HT7R)in 5-HT signaling pathway in the hippocampus.The results showed that:PD significantly regulated the abnormal changes of body weight,food and water intake and blood routine indexes in rats with DHD,and significantly im-proved the pathological damage of colonic tissues;PD significantly lowered the expression of in-flammatory cytokines IL-1β,IL-6,IFN-γ,and TNF-α in hippocampus of rats with DHD(P＜0.05),and significantly reduced the expression of TPH1 mRNA in hippocampus of rats with DHD(P＜0.05).PD could increased the expression of 5-HT4R and 5-HT7R in the hippocampus of rats with DHD;reduced the expression of 5-HT3R and TPH in the hippocampus,among which 5-HT3R expression was significantly reduced.This study suggests that PD can affect the function of hippocampus in rats with DHD by regulating the 5-HT signaling pathway.

This study aims to investigate the effects of Pulsatilla decoction(PD)on the 5-HT sig-naling system in the hippocampus of damp-heat diarrhoea(DHD)rats.Twenty-four male SD rats were randomly divided into four groups including the blank group,the model group,the PD group and the self-healing group.Except for the blank group,the rats in each group were induced by"high sugar and high fat,high temperature and high humidity,and E.coli poisoning"to establish a of rat model DHD,and were treated by gavage with PD.Changes in body weight,temperature,food intake and water intake,routine blood tests and histopathological changes in the colon were recor-ded to comprehensively determine the modelling condition of rats with DHD;histopathological changes in the hippocampus of rats were observed,and real-time fluorescence PCR was used to de-termine the expression of IL-1β3,IL-6,TNF-α,IFN-γ and TPH1 mRNA in the hippocampus;West-ern blot and immunohistochemistry were used to detect the protein expression of tryptophan hydroxylase 1(TPH1),receptors(5-HT3R,5-HT4R,5-HT7R)in 5-HT signaling pathway in the hippocampus.The results showed that:PD significantly regulated the abnormal changes of body weight,food and water intake and blood routine indexes in rats with DHD,and significantly im-proved the pathological damage of colonic tissues;PD significantly lowered the expression of in-flammatory cytokines IL-1β,IL-6,IFN-γ,and TNF-α in hippocampus of rats with DHD(P＜0.05),and significantly reduced the expression of TPH1 mRNA in hippocampus of rats with DHD(P＜0.05).PD could increased the expression of 5-HT4R and 5-HT7R in the hippocampus of rats with DHD;reduced the expression of 5-HT3R and TPH in the hippocampus,among which 5-HT3R expression was significantly reduced.This study suggests that PD can affect the function of hippocampus in rats with DHD by regulating the 5-HT signaling pathway.