Inhibition of Lipase Activities by Citrus Pectin

Abstract

SummaryThe oral administration of pectin to rats reduced and delayed the peak plasma triacylglycerol concentration. Pectin inhibited the hydrolysis of trioleoylglycerol emulsified with soybean phosphatidylcholine by pancreatic, carboxylester, and lingual lipases in a con centration-dependent manner. However, the effective concentration of pectin for lingual lipase was 100 times lower than that for pancreatic lipase. Pectin did not inhibit the tribu tyrin and p-nitrophenylbutyrate-hydrolyzing activities by pancreatic and carboxylester lipase. When low molecular weight pectin was assayed, pectin at a molecular weight of 90,000 (MW 90) most strongly inhibited three lipase activities. When the effect of pH on pectin inhibition was analyzed using pancreatic lipase, strong inhibition was observed at an acidic pH (below pH 7.0). In the assay system, the pancreatic lipase protein levels in the supernatant and fat layer were estimated by Western blotting with an anti-pancreatic lipase antibody. Pectin reduced the amount of pancreatic lipase protein in the fat layer in a concen tration-dependent manner and concomitantly increased that in the supernatant. These results suggest that pectin may interact with emulsified substrates and inhibit the adsorp tion of lipase to the surface of substrate emulsion. Key Words pectin, pancreatic lipase, lingual lipase, triacylglycerol digestion It is well known that pectin lowers plasma and liver cholesterol in rats with diet-induced hyperlipidemia (1 3). Pectin intake resulted in lower plasma LDL choles terol concentrations, whereas plasma VLDL and HDL cholesterols were not affected by pectin intake in guinea pigs (4). In humans, pectin also reduced total choles terol and LDL cholesterol concentrations, but HDL cho lesterol was not significantly influenced by pectin (5). Though numerous studies have shown that pectin has been shown to lower cholesterol concentrations in sev eral animal and human studies, few studies have ex amined the effect of pectin on the triacylglycerol metabolism. In this study, we investigated in detail, the effect of pectin on dietary triacylglycerol digestion and absorption.In mammals, dietary triacylglycerol digestion is mediated by three main enzymes: preduodenal (lingual or gastric), carboxylester, and pancreatic lipases. Under acidic conditions in the stomach, fat is hydrolyzed by preduodenal lipase(s), which leads to the hydrolysis of 10-30% of the dietary triacylglycerols to glycerols (mainly diacylglycerol) and free fatty acids (6). Pancre atic lipase hydrolyzes triacylglycerols to 2-monoacylg lycerol and free fatty acids. Carboxylester lipase has a broad substrate specificity, acting readily on triacylglyc erols, diacylglycerols, monoacylglycerols, and choles terol esters (7), and catalyzes the hydrolysis of water soluble substrates such as methyl butyrate and p-nitro phenylbutyrate. Typical substrates for these enzymes are long-chain triacylglycerols, which are separated from the aqueous medium by the surface phase. In con trast to their substrates, the...

Impact of pectin properties on lipid digestion under simulated gastrointestinal conditions: Comparison of citrus and banana passion fruit (Passiflora tripartita var. mollissima) pectins

“…For this reason, there has been considerable interest in the development of effective strategies to reduce the caloric content of foods, or to reduce the spike in blood lipids that occurs after consuming a fatty meal. Several studies have suggested that certain types of dietary fibers can inhibit the digestion and absorption of lipids (Beysseriat, Decker, & McClements, 2006;Edashige, Murakami, & Tsujita, 2008;Tsujita et al, 2003;Yonekura & Nagao, 2009). Numerous physicochemical and physiological mechanisms may contribute to this effect, including the ability of dietary fibers to alter the rheology of the gastrointestinal fluids, to bind digestive components (such as bile salts and digestive enzymes), to alter the aggregation state of lipid droplets, to form protective coatings around lipid droplets, and to be fermented within the large intestine by colonic bacteria (Grabitske & Slavin, 2009;Lattimer & Haub, 2010;McClements, Decker, & Park, 2009).…”

Inhibitory Effect of Pectin from the Segment Membrane of Citrus Fruits on Lipase Activity

“…In our previous research, low-molecularweight fractions from commercial citrus pectin [in particular, molecular weight (M.W. ): 90,000] have been shown to associate with substrates and inhibit pancreatic lipase activity ( 16 ). Therefore, studies with appropriate pectin will clarify the cause of their dietary effects.…”

Hypolipidemic Effect of Pleurotus eryngii Extract in Fat-Loaded Mice

“…Chitinchitosan and citrus pectin are both high molecular weight lipase inhibitors (19,20). However, both of these inhibitors are poorly soluble in water.…”

“…As pancreatic lipase inhibitors prevent postprandial hyperlipidemia (20)(21)(22)(23), PEE may also have prevented postprandial hyperlipidemia through low intestinal absorption of dietary fat by inhibiting pancreatic lipase. To examine this possibility, we determined the plasma TG levels after oral administration of corn oil with or without PEE to mice.…”