Satietogenic Protein from Tamarind Seeds Decreases Food Intake, Leptin Plasma and <b><i>CCK-1r</i></b> Gene Expression in Obese Wistar Rats

Abstract

Objective: This study evaluated the effect of a protein, the isolated Trypsin Inhibitor (TTI) from Tamarindus indica L. seed, as a CCK secretagogue and its action upon food intake and leptin in obese Wistar rats. Methods: Three groups of obese rats were fed 10 days one of the following diets: Standard diet (Labina®) + water; High Glycemic Index and Load (HGLI) diet + water or HGLI diet + TTI. Lean animals were fed the standard diet for the 10 days. Food intake, zoometric measurements, plasma CCK, plasma leptin, relative mRNA expression of intestinal CCK-related genes, and expression of the ob gene in subcutaneous adipose tissue were assessed. Results: TTI decreased food intake but did not increase plasma CCK in obese animals. On the other hand, TTI treatment decreased CCK-1R gene expression in obese animals compared with the obese group with no treatment (p = 0.027). Obese animals treated with TTI presented lower plasma leptin than the non-treated obese animals. Conclusion: We suggest that TTI by decreasing plasma leptin may improve CCK action, regardless of its increase in plasma from obese rats, since food intake was lowest.

Trypsin inhibitors: promising candidate satietogenic proteins as complementary treatment for obesity and metabolic disorders?

“…However, TTI was also able to decrease the relative expression of this gene in obese animals when compared to those without treatment. This may be considered a positive effect since it has also been observed in obese animals receiving a standard diet, which may be related to the sensitivity to the effects of CCK 72 .…”

“…In a study similar to that of Carvalho et al 16 ,. Costa et al 72 . also evaluated the effect of TTI on an experimental model of obesity.…”

“…Subsequent studies involving the trypsin inhibitor of tamarind seeds, isolated 72 and purified 17 these proteins administering them by gavage in Wistar rats with diet-induced obesity, evaluating its action on CCK and leptin. At both stages of purification, in both studies, the inhibitor was able to reduce serum leptin concentrations five-fold compared to the untreated obesity group.…”

“…in these studies there was no influence on CCK concentrations in obese animals. It was assumed that the satiety effect of the tamarind inhibitor has no connection neither with the antitryptic activity nor with the modulation of CCK concentrations 14 , 17 , 72 .…”

“…As already described, a series of hormones with satiety activity contribute to energy balance and food consumption regulation. These studies have pointed out that trypsin inhibitors may not have exclusive action on CCK but also on leptin 17 , 72 .…”