AUTHOR=Yue Qin , Zeng Xinyi , Yang Minlan , Chen Jinhao , Liu Lin , Liu Hui TITLE=Bletilla striata polysaccharide induces autophagy through PI3K/AKT signaling pathway to promote the survival of cross-boundary flap in rats JOURNAL=Frontiers in Pharmacology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1544932 DOI=10.3389/fphar.2025.1544932 ISSN=1663-9812 ABSTRACT=IntroductionDistal flap necrosis is a common problem in flap transplantation. Bletilla striata polysaccharide (BSP) is the main medicinal component of traditional Chinese medicine Bletilla striata. The purpose of this study was to investigate the mechanism of BSP promoting flap survival.MethodsThe control group, BSP low, medium and high dose groups, BSP + autophagy inhibitor 3-methyladenine (3-MA) group were designed to establish a model of cross-boundary flap in rat back. After 7 days of postoperative administration, the samples were taken.ResultsThe optimal dose of BSP was determined to be 250 mg/kg/d according to the survival rate of flap, microvessel density, intra-arterial diameter, expression of vascular-related protein and pharmacological toxicity. By detecting the expression level of autophagy-related proteins, it was found that BSP could activate autophagy. After autophagy was blocked, the therapeutic effect of BSP was reversed. In addition, BSP activated the PI3K/AKT signaling pathway.DiscussionStudies have shown that BSP induces autophagy by activating PI3K/AKT signaling pathway, thereby promoting angiogenesis and improving survival rate of flap.