Dietary Lectin Lowers Serum Cholesterol and Raises Fecal Neutral Sterols in Cholesterol-Fed Rats

Abstract

SummaryThis study examined the influence of a low level of dietary lectin (0.34%), at a dose that did not affect body weight or food intake, on the concentration of serum choles terol and fecal excretion of neutral sterols in rats fed a diet containing 0.50% cholesterol and 0.13% sodium cholate for 12d. In experiment 1, rats fed a diet with 0.34% lectin, con canavalin A, had significantly lower concentrations of serum total cholesterol and hepatic cholesterol, a higher ratio of HDL-cholesterol to total cholesterol, enhanced excretion of fecal neutral sterols and reduced apparent cholesterol absorption or digestibility as com pared with rats fed a diet without lectin. Fecal excretion of acidic sterols was unaffected by dietary lectin. In contrast, dietary 0.34% lectin had no significant effect on concentrations of serum total protein or glucose. In experiment 2, we examined whether the cholesterol lowering activity of the lectin was responsibility for its carbohydrate-binding activity. The effect of dietary lectin on concentrations of serum and hepatic cholesterol and excretion of fecal neutral sterols was prevented by simultaneous administration of methyl-a-D-man nopyranoside with specific affinity for the carbohydrate-binding sites of the lectin. These results suggest that dietary lectins might reduce concentrations of serum and hepatic cho lesterol by a mechanism involving higher excretion of neutral sterols and that these alter ations might be associated with the carbohydrate-binding activity of lectin.

Canavalia ensiformis Protein Extract Effect Toward Serum Lipid Profile of Hypercholesterolemic Sprague Dawley Rat

“…The result of current study was reciprocal with a study by Nimenibo-Uaida (2003), which stated that the administration of Jack Bean extract in diabetic rats can reduce the plasma cholesterol level from 2.98±0.05 mmol/L to 1.80±0.03 mmol/L and reduce triglyceride level form 1.83±0.01 mmol/L to 0.76±0.05 mmol/L after ten days of treatment. Kayashima et al, (2005) also showed that Concanavalin A (one of the protein within the Jack Bean) had a positive effect on serum cholesterol level. The cholesterol levels before and after the treatment were 3.10±0.34 mmol/L and 0.592±0.057 mmol/L, respectively.…”

“…Lectin Concavalin A affects lipid absorption in gastro intestinal tract without affecting protein and glucose absorption. Concavalin A binds to glycolipid in gastro intestinal tract and prevents the activity of brush border enzyme in enterocyte, thereby limiting cholesterol absorption (Kayashima et al, 2005).…”

“…Mechanism of retransportation by HDL is known to reduce the cholesterol level in extra hepatic tissues. The HDL delivers the cholesterol to the liver to be excreted (Kayashima et al, 2005).…”

“…Study on alloxan-induced rats (Nimenibo-Uadia, 2003) showed that there was a significant decrease of cholesterol and triglyceride level after administration of Jack Bean extract compared to control group. Kayashima et al, (2005) showed that administration of 0.34% Concanavalin A, which is one of protein fraction of Jack Bean, was proven to exert a positive effect. The treatment group had both lower serum cholesterol and triglyceride levels than control group.…”

Identification of the active protein in rice bran protein having an inhibitory activity of cholesterol micellar solubility

“…Kayashima et al suggested that serum total cholesterol and fecal neutral sterols excretion were significantly increased in rats fed a cholesterol-enriched diet with 0.34% lectin (concanavalin A) for 12 days. 17) Thus, the cholesterol-lowering effect may be partially related to the lectin derived from RBP. Carvalho et al reported that plant non-specific lipid-transfer proteins have the ability to bind or transfer various types of hydrophobic molecules in vitro, such as fatty acids, fatty acyl-CoA, phospholipids, and glycolipids.…”