Corn silk (Stigma maydis) aqueous extract attenuates high-salt induced glucose dysregulation and cardiac dyslipidemia: Involvement of phosphoinositide 3-kinase activities

Background: Corn silk (Stigma maydis) is the long silky tuft of hairs from the female inflorescence of maize (Zea mays L) with rich antioxidant ctivity and free radicals scavenging capacity. High-salt diet on the other hand, has been shown to alter vascular and alter metabolic disorders. However, the exact ameliorating mechanism of corn silk (CS) effect is still being widely studied. This study examined the effect of aqueous corn silk extract on high saltinduced cardiac glucose and lipid dysmetabolism. Methods: Twenty male Sprague-Dawley rats (100-110g) were randomly selected into four groups (n=5) after a week of acclimatization and fed with rat chow (CTR), corn silk extract (CS; 500 mg/kg), high salt diet (HSD; 8%) and corn silk extract plus high salt feed (HSD; 8% + CS; 500 mg/kg) respectively for six weeks. At the end of the experimental procedure, each animal was anesthetized by exposure to chloroform vapor and blood samples collected by cardiac puncture. Data were analyzed and expressed as mean ± SEM and p-values < 0.05 were accepted as significant. Results: Corn silk extract resulted in attenuated plasma and cardiac glycogen production, triglycerides, free fatty acids, and total cholesterol associated with high-salt diet. However, the plasma level of  Phosphoinositide 3-kinase (PI3K), and nitric oxide was significantly elevated in CS groups compared with control. Corn silk extract also decreased fasting blood glucose, insulin, and glycogen synthase activity (P<0.05) in HSD-fed rats. Conclusion: It is noteworthy from our data that corn silk possesses antilipidemic and glucoregulatory properties associated with enhanced phosphoinositide-3-kinases (PI3K) activity, an insulin dependent signaling pathway and may form an important component of nutritional candidate for ameliorating cardiometabolic diseases. Keywords: Cardiac dysmetabolism, Corn silk, Glucose dysregulation, High-salt diet, Phosphoinositide 3- kinase