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

Abstract

Background: Corn silk (Stigma maydis) is the long silky tuft of hairs from the female
inflorescence of maize (Zea mays L) with rich antioxidant activity 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.