Hypocholesterolaemic and antioxidant efficiency of chickpea (Cicer arietinum) protein hydrolysates depend on its degree of hydrolysis in cholesterol-fed rat

Purpose The purpose of this study was to determine the effects of chickpea (Cicer arietinum) protein hydrolysates prepared at two degrees of hydrolysis (DH) on lipoprotein profile and on oxidant status in cholesterol-fed rats. Design/methodology/approach Eighteen male Wistar rats (220 ± 10 g) were divided into three groups and fed for 30 days a diet containing 20 per cent casein supplemented with 1 per cent cholesterol and 0.5 per cent cholic acid. During the experimentation, the first and the second groups received daily by gavage 250 mg of chickpea protein hydrolysates/rat at DH = 8 per cent (CPH8) and DH = 17 per cent (CPH17), respectively. The third group, named control group (CG), received water under the same conditions. Findings Serum total cholesterol concentrations were reduced in CPH8 (p < 0.0073) and CPH17 (p < 0.0004) groups versus CG. This reduction corresponded to a lower very-low-density lipoprotein (VLDL)-cholesterol (p < 0,0019). CPH17 reduced low-density lipoprotein- and high-density lipoprotein (HDL)-cholesterol (p < 0.0001) but increased apolipoprotein A4 (p < 0.002) concentrations and lecithin-cholesterol acyltransferase activity (p < 0.0001). APOA1 remained unchanged in the treated groups. Liver total and esterified cholesterol contents were twofold lower in both treated groups versus CG. CPH8 increased triacylglycerols and phospholipids (p < 0.0001) contents, while CPH17 decreased those of unesterified cholesterol (p < 0.0016). Compared with CG, CPH8 and CPH17 reduced serum (p < 0.0001) and lipoprotein hydroperoxides by stimulating paraoxonase activity (p < 0.0001). However, only CPH17 treatment reduced serum, VLDL- and HDL-malondialdehyde contents and improved glutathione peroxidase activity (p < 0.061). Originality/value Thus, chickpea protein hydrolysates and especially hydrolysed at DH = 17 per cent may have a great potential for use as a nutraceutical to reduce hypercholesterolaemia and, by consequence, oxidative stress. Therefore, the degree of enzymatic hydrolysis has a significant influence on the production of potent bioactive peptides.