Cannabidiol Alleviates Symptoms of Senile Atopic Dermatitis by Inhibiting Fibroblast Senescence

Background With an aging population, the incidence of senile atopic dermatitis (AD) is increasing. As a nonpsychoactive ingredient of cannabis, cannabidiol (CBD) has a significant effect on the treatment of various skin inflammatory diseases and may also inhibit fibroblast senescence, but it has not been used in the treatment of senile AD. Objective To observe the effect and explore the potential mechanism of CBD on senile AD. Methods The senile AD model was established using 2,4‐dichloronitrobenzene (DNCB) in 48 six‐month‐old aging‐accelerated mice/susceptible 8 (SAMP8) models (with equal male and female mice). The skin on the back and ears of mice was observed and assessed visually to obtain a skin inflammation score. The frequency of scratching the back and ear skin within 10 min during fixed time intervals was recorded to determine the scratching frequency. Quantifying the number of infiltrating inflammatory cells by H&E staining, the morphology of fibroblasts was checked by transmission electron microscopy, the expression levels of senescence‐associated secretory phenotype (SASP) were detected by ELISA, and the protein expressions of p16‐INK4a and CDK4 were tested by Western blot. Results High‐dose CBD alleviated the symptoms of senile AD, reduced skin dermatitis scores, decreased the release of inflammatory factors such as IL‐1β and IL‐18, and alleviated cutaneous inflammatory responses. Meanwhile, it maintained the morphology of dermal fibroblasts, regulated cyclins, and inhibited fibroblast senescence. Conclusion CBD alleviated the symptoms of senile AD in SAMP8 by inhibiting the senescence process of dermal fibroblasts.