New therapy for oral ulcer: Evodia rutaecarpa patch combined with acupoint application

Abstract

Background: Oral ulcer is the most common and easily recurrent disease in stomatology, which influence the patients’ communication, normal dietary, and sleep. Evodia rutaecarpa (ER) is a traditional Chinese herbal medicine recorded in ancient Chinese medical books, which has a medicinal history of more than 2,000 years. Clinically, the application of ER at plantar Yongquan point (KI1) is effective in the treatment of oral ulcer. The purpose of this study was to combine the modern transdermal drug delivery system with traditional Chinese medicine to develop the transdermal absorption patch of ER and apply it to the treatment of oral ulcer at Yongquan point of plantar. Methods: Firstly, the medicinal materials of ER were extracted and the extracted materials were prepared into dispersed ER patch. The formulation and preparation process were screened by orthogonal design method and single factor investigation method. The adhesive and transdermal properties of the patch were used as the evaluation index of the preparation. Secondly, Wistar rats were used as experimental animals to establish a rat model of mouth ulcers. Wistar rats were randomly divided into normal group, model group (A), model group (B), low dose group, medium dose group and high dose group. the efficacy of ER on rat’s oral ulcer model was evaluated through three aspect such as apparent index, pathological index and biochemical index. Results: The patch had suitable adhesion and good skin penetration, which was an effective treatment for oral ulcer. In vivo pharmacodynamic studies, compared with the normal group, the body mass and food intake of rats in each group after modeling decreased, the amount of drinking water increased, the tissue structure of oral mucosa was damaged, and the levels of inflammatory factors (TNF-α, IL-6) and malondialdehyde increased, the levels of anti-inflammatory factors (IL-10), cell growth factor (epidermal growth factor, TGF-β 1 ) and superoxide dismutase decreased. Compared with the model group, the body weight and food intake of each dosing group increased, water consumption decreased, the oral mucosal tissue structure was more complete, the levels of TNF-α, IL-6 and malondialdehyde decreased, the levels of IL-10, epidermal growth factor, TGF-β1 and superoxide dismutase increased, and the changes of various indexes were dose-related. Conclusion: ER patch can inhibit inflammatory reaction, enhance the antioxidant defense ability of the body, and promote the repair of damaged oral mucosa, so as to play an effective role in the treatment of oral ulcer.