ε-polylysine inhibits pancreatic lipase activity and suppresses postprandial hypertriacylglyceridemia in rats

Abstract

ε-Polylysine (ε-PL) has been used as a food additive in Japan for many years. In this study, it inhibited human and porcine pancreatic lipase activity in substrate emulsions containing bile salts and phosphatidylcholine, in the concentration range of 10-1000 mg/L. At the same concentrations, it also destroyed the emulsifying activity, suggesting that lipase inhibitory activity and emulsion breakdown activity were associated. ε-PL inhibited porcine pancreatic lipase activity and destroyed emulsion breakdown activity at 1000 mg/L in the substrate containing bile salts and phosphatidylcholine alone. ε-PL did not inhibit lipase activity or affect emulsifying activity at 1000 mg/L in the substrates containing arabic gum and polyvinyl alcohol. A comparison of lipase inhibitory activity between ε-PL and three types of α-PL with differing polymerization rates was performed. The lipase inhibitory activity of ε-PL was not different from that of α-PL (44 lysine residues). ε-PL maintained its inhibitory activity after incubation with trypsin, α-chymotrypsin and pepsin, whereas α-PL did not. The effect of ε-PL on postprandial hypertriacylglyceridemia was investigated in rats. The plasma triacylglycerol concentration in rats intragastrically administered ≥ 15 mg/kg of both fat emulsion and ε-PL was significantly lower at 2 and 3 h after administration than that in rats administered fat emulsion alone (P < 0.05). These results strongly suggest that ε-PL is able to suppress dietary fat absorption from the small intestine by inhibiting pancreatic lipase activity.