Preventive activity of food against oxidative stress-induced disruption of intestinal epithelial barrier function and the effect of cooking on the activity

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 16500525
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Eating habits, studies on eating habits
• Research Institution: Doshisha Women's College of Liberal Arts
• Principal Investigator: MARIKO Manabe Doshisha Women's College of Liberal Arts, Faculty of Human Life and Science, Associate Professor, 生活科学部, 准教授 (50329968)
• Project Period (FY): 2004 – 2006
• Keywords: Caco-2 / oxidative stress / transepithelial electrical resistance / vegetables / 加熱調理

Research Abstract

One of the most important roles of the intestinal epithelium is to act as a mucosal barrier, which owes considerably to the rate-limiting barrier by intercellular tight junction of intestinal epithelium. However, oxidative stress would induce disruption of intestinal epithelial barrier function. In this study, we examined that the preventive activity of raw and cooked vegetables against oxidant (2.5 mM H_2O_2)-induced decrease in transepithelial electrical resistance (TER) in a Caco-2 cell monolayer.
Though aqueous extracts from asparagus, red perilla, pumpkin and tomato maintained the TER in the Caco-2 cell monolayer after the addition of H 2O 2, these preventive activities against H_2O_2-induced decrease in the TER were completely disappeared by the in vitro digested vegetables except tomato. These results suggested that the preventive activity of vegetable is lost by digestion. However, the cooked vegetables digested in vitro, especially asparagus, purple asparagus and tomato inhibited H_2O_2-induced decrease in the TER. These results indicated that the internal enzymes in vegetables were inactivated by cooking and that the effective substances in the vegetables did not flow into boiled water during cooking. Thus, cooking is effective to retain the preventive activity of vegetables after digestion.
The activities in the samples prepared from those vegetables did not correlate with their DPPH radical scavenging activities and with the polyphenol contents. The preventive activities of food against oxidative stress-induced disruption of intestinal epithelial barrier function should be assessed by the system considering the process of cooking and digestion and using the model proper for intestinal epithelium.