Four types of winged yam ( Dioscorea alata L.) resistant starches and their effects on ethanol-induced gastric injury in vivo

Abstract Physicochemical properties and gastroprotection of four types of resistant starch (RS) including native (RS2), retrograded (RS3), cross-linked with sodium trimetaphosphate/sodium tripolyphosphate (RS4) and complexed with palmitic acid (RS5) resistant starches were investigated and compared. After modification, there was no significant change in RS content in addition to the decline in the RS3. The crystal type of RS2 was B-type pattern. During modification, RS3 and RS5 lost their granular shape and crystalline structure collapsed, while RS4's granular structure was not destroyed and maintained the B-type crystalline pattern. In addition, gastroprotective effect of the four types of RS on gastric ulcer induced by ethanol in mice was investigated. Pretreatment with the four types of RS had an obvious gastroprotection compared to ethanol group that significantly attenuated the level of histopathological injury and ulcerative lesion index (ULI). Also, the excess malondialdehyde (MDA) and the reduced superoxide dismutase (SOD) induced by ethanol can be effectively inhibited. Furthermore, there were more SCFAs (short chain fatty acids) generated in colon with the four starches when compared with ethanol group. The results demonstrated that the four types of RS were proved to be effective on ethanol-induced gastric injure probably by ameliorating oxidative stress, generating more SCFAs and promoting gastric emptying. Of the four RS samples tested, the high dose groups of RS3 and RS5 showed the best activity. This study reported four kinds of gastro-protection starches and provided useful information for functional food and pharmaceutical industries.