Inhibitory activity of dehulled adlay extrudate against ethanol-induced gastric mucosal injury and stability tests of active indicative components

Abstract

Non-Helicobacter pylori-associated gastric ulcers are increasingly prevalent worldwide and represent a significant health concern. The edible portion of adlay seeds (Coix lachryma-jobi L. var. ma-yuen Stapf), dehulled adlay (DA), consists of approximately 92% endosperm and 8% bran and is commonly processed into extrudates with low water activity and high storage stability. Adlay bran (AB) is particularly rich in dietary fiber, phytosterols, and phenolic compounds, which have been reported to exert gastroprotective effects. This study aimed to evaluate the protective effects of DA extrudate (DAE) against 50% ethanol-induced gastric ulcers in vivo and to investigate changes in proximate composition and bioactive components during storage. The results showed that a diet containing 20% DAE significantly reduced the gastric ulcer index (UI) in Wistar rats. The protective effects were associated with enhanced endogenous antioxidant defense, particularly through increased levels of non-protein sulfhydryl (NPSH) compounds such as glutathione. Stability evaluation demonstrated that dietary fiber and total triterpenoids remained stable throughout storage. Moreover, β-sitosterol and phenolic acids, including vanillic acid, p-coumaric acid, and ferulic acid, remained detectable after a 6-month accelerated storage stability test and may serve as potential indicator compounds for quality control of functional DAE products.