ObjectiveTo observe the effects of Hedysari Radix polysaccharide on the apoptosis of gastric sinus smooth muscle cells and explore the underlying mechanism via the insulin-like growth factor-1 （IGF-1）/phosphatidylinositol 3-kinase （PI3K）/serine-threonine kinase （Akt） pathway in the rat model of diabetic gastroparesis （DGP）. MethodSixty-two Wistar male rats were randomized into a blank group （n=12） and a modelling group （n=50）. The rat model of DGP was established by small-dose multiple intraperitoneal injections of streptozotocin combined with an irregular high-fat and high-sugar diet for 4 weeks. The modeled rats were randomized into model group， mosapride citrate （1.35 mg·kg^-1）， and high-， medium-， and low-dose （200， 100， and 50 mg·kg^-1， respectively） Hedysari Radix polysaccharide groups. The rats were administrated with corresponding drugs by gavage， and those in the blank and model groups with equal volumes of pure water by gavage once a day for 8 consecutive weeks. The random blood glucose and body mass were measured every 2 weeks， and gastric emptying rate was calculated. Hematoxylin-eosin （HE） staining was used to observe the pathological changes of smooth muscle in gastric antrum， and terminal deoxynucleoitidyl transferase-mediated nick-end labeling （TUNEL） was employed to detect the apoptosis of smooth muscle cells in the gastric antrum. The expression of IGF-1， phosphorylated （p）-PI3K， and p-Akt in the smooth muscle of gastric sinus tissue was detected by immunohistochemistry. Western blot was employed to determine the protein levels of IGF-1， p-PI3K/PI3K， p-Akt/Akt， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax） in the smooth muscle of the gastric antrum. ResultCompared with the blank group， the model group showed elevated random blood glucose at all time points （P<0.01）， decreased body mass and gastric emptying rate （P<0.01）， increased apoptotic index of smooth muscle cells in the gastric antrum （P<0.01）， down-regulated protein levels of IGF-1， p-PI3K/PI3K， p-Akt/Akt， and Bcl-2， and up-regulated protein level of Bax （P<0.01）. Compared with the model group， the 8 weeks of drug administration lowered the random blood glucose， increased the body mass and gastric emptying rate （P<0.05， P<0.01）， decreased the apoptotic index of smooth muscle cells in the gastric antrum （P<0.05， P<0.01）， up-regulated the protein levels of IGF-1， p-PI3K/PI3K， p-Akt/Akt， and Bcl-2， and down-regulated the protein level of Bax （P<0.05， P<0.01）. Compared with the mosapride citrate group，the administration of low-dose Hedysari Radix polysaccharide for 6 and 8 weeks lowered the random blood glucose and decreased the body mass （P<0.05， P<0.01），low and medium-dose Hedysari Radix polysaccharide decreased the gastric emptying rate and the apoptotic index of smooth muscle cells in the astragaloside low-dose group decreased （P<0.05）. The protein levels of IGF-1，p-PI3K/PI3K，p-Akt/Akt and Bcl-2（low dose）were down-regulated and the protein level of Bax was up-regulated by low doses of Hedysari Radix polysaccharide （P<0.05， P<0.01）. Compared with high-dose Hedysari Radix polysaccharide， low-dose Hedysari Radix polysaccharide elevated random blood glucose and reduced body mass after 6 and 8 weeks of administration （P<0.05， P<0.01）， and the low and medium doses decreased the gastric emptying rate， increased the apoptotic index of smooth muscle cells in the gastric antrum （P<0.05， P<0.01）， down-regulated the protein levels of IGF-1， p-PI3K/PI3K， p-Akt/Akt， and Bcl-2， and up-regulated the protein level of Bax （P<0.05， P<0.01）. Compared with the medium-dose group，the low-dose group of Hedysari Radix polysaccharide had lower body mass，lower gastric emptying rate in rats，higher apoptotic index of smooth muscle cells in gastric sinus tissue after 6 and 8 weeks of administration （P<0.05， P<0.01）， and lower protein expression of IGF-1，p-PI3K/PI3K，p-Akt/Akt. ConclusionHedysari Radix polysaccharide protects the smooth muscle cells in gastric antrum against apoptotic injury and promotes gastric motility by activating the IGF-1/PI3K/Akt signaling pathway， as manifested by the up-regulated expression of IGF-1， p-PI3K， p-Akt， and Bcl-2 and down-regulated expression of Bax.

Diabetic gastroparesis （DGP） is a common diabetic neuropathy that affects the normal function of gastric motility and emptying. Clinically， it often manifests as abdominal distension， nausea and vomiting， early satiety， dyspepsia， etc. The pathogenesis of DGP is multifactorial， closely related to many factors， such as chronic hyperglycemia， neuropathy， autonomic nervous system disorders， inflammation， and oxidative stress. These factors can interact with each other， leading to delayed gastric emptying and the occurrence of related symptoms. Traditional Chinese medicine （TCM） has significant advantages in the prevention and treatment of DGP， including a long history， remarkable efficacy， individualized treatment， diverse therapeutic formulations， and improvement in the quality of life. Additionally， TCM is known for its low adverse reactions， good tolerance， and multi-targeted effects， making it an important approach in the management of DGP. Previous research has found that the main mechanisms of Chinese medicine in the prevention and treatment of DGP include the regulation of gastrointestinal hormones， inhibition of inflammatory responses， reduction of oxidative stress， enhancement of interstitial cells of Cajal activity， inhibition of pyroptosis， and modulation of related signaling pathways such as stem cell factor （SCF）/cellular growth factor receptor （c-Kit）， adenosine monophosphate-activated protein kinase （AMPK）， Ras homologous genome member A （RhoA）/Rho-associated coiled-coil forming kinase （ROCK）. This article primarily summarized the research progress on Chinese medicine in preventing and treating DGP through the inhibition of inflammatory responses， reduction of oxidative stress， enhancement of interstitial cells of Cajal activity， inhibition of pyroptosis， and regulation of related signaling pathways， aiming to provide a reference and basis for further research on the application value of Chinese medicine in the prevention and treatment of DGP.