Influence of soybean trypsin inhibitor on small bowel enzyme activities during rotavirus infection in malnourished infant mice

Rotavirus (RV) is considered to be one of the major causes of acute episodi c diarrhoea throughout the world. This study was undertaken to investigate the effect of soybean trypsin inhibitor (TI) on brush-border enzymes during rotavirus infection in protein energy malnourished (PEM) infant mice. Anim als were divided into 4 groups, namely controls, PEM, PEM+RV and PEM+RV+TI (n = 36 each). Group 1 and 2 animals were orally inoculated with 50 mul of normal saline each. Group 3 animals were orally inoculated with 50 mul of 1 00 ID50 dose of RV stock each. Group 4 animals were similarly inoculated wi th 0.6 mg TI/g body weight along with 50 mul of RV stock each. Animals were examined daily for diarrhoea and their body weight was recorded on alterna te days postinoculation (dpi). Animals were killed by cervical dislocation after being given light chloroform anesthesia on 0, 1, 3, 5, 7 and 10 dpi. Small intestines were excised and homogenized in normal saline. Proteins, g ammaglutamyl transpeptidase, alkaline phosphatase and disaccharidases were estimated in jejunum and ileum. Body weight was significantly reduced in PE M animals and with RV infection. Histologically, focal areas of vacuolar de generation of lining epithelium were seen in RV-infected animals. Disacchar idases and other enzyme activities were decreased significantly in the PEM group compared to healthy controls and further depressed with RV infection in malnourished animals as compared to non-infected PEM. The enzyme activit ies were restored in animals receiving TI along with RV compared to the gro up receiving RV without TI. With the administration of soybean TI, the acti vities of disaccharidases, alkaline phosphatase, gammaglutamyl transpeptida se and intestinal architecture were restored showing a protective effect in PEM during RV infection. Copyright (C) 2000 S. Karger AG. Basel.