Effect of ingested winged bean lectin on gastrointestinal function in the rat

Area of Science:

• Biochemistry
• Toxicology
• Animal Nutrition

Background:

• Winged bean lectin (WBLF) is a plant protein with potential toxicity.
• The small intestine's brush border membrane contains hydrolases crucial for nutrient absorption.
• Previous studies suggested WBLF interferes with intestinal function.

Purpose of the Study:

• To investigate the toxicological mechanisms of ingested winged bean lectin (WBLF).
• To determine WBLF's effect on brush border membrane hydrolase activities in rats.
• To provide evidence for WBLF's interaction with the small intestine's luminal surface.

Main Methods:

• Rats were fed a high-sucrose diet (HSD) with or without WBLF, heated WBLF, or soybean trypsin inhibitor.
• Changes in sucrase, alkaline phosphatase, and leucine aminopeptidase activities were measured over time.
• WBLF's effects were compared to concanavalin A from previous studies.

Main Results:

• Raw WBLF, but not heated WBLF or soybean trypsin inhibitor, restrained the adaptive increase in sucrase activity in rats on an HSD.
• WBLF administration affected the time-course of sucrase, alkaline phosphatase, and leucine aminopeptidase activities.
• These effects mirrored those of concanavalin A observed previously.

Conclusions:

• The toxicity of ingested winged bean lectin involves its binding to the small intestine's luminal surface.
• This binding interferes with the proper formation and function of the brush border membrane.
• WBLF's impact on hydrolase activities supports its role in disrupting intestinal barrier function.