Pancreatic lipase activity

Within the small intestine, bile-acid binding interferes with micelle formation. Nauss et al. [268] reported that, in vitro, chitosan binds bile acid micelles in toto, with consequent reduced assimilation of all micelle components, i.e., bile acids, cholesterol, monoglycerides and fatty acids. Moreover, in vitro, chitosan inhibits pancreatic lipase activity [269]. Dissolved chitosan may further depress the activity of lipases by acting as an alternative substrate [270]. 

Several studies have been conducted on calcium-fat interactions in human infants (64-70). Low synthesis of bile salts and low pancreatic lipase activity may be responsible for poorer fat utilization in infants than in adults (63,71). Fat from infant formulas may be lower than that from human milk because of the lack of a bile-stimulated lipase in the former (72). In infants, fat absorption tends to decrease with increase in fatty acid length, with lower degree of saturation, and with increase of total fat (3). Triglyceride structure may also influence fat absorption in the infant and, thus, indirectly, might also affect calcium absorption in the infant. 

Asafetida, administered orally to albino rats at a dose of 250 mg% for 8 weeks, enhanced pancreatic lipase activity, stimulated pancreatic amylase and chymotrypsin. The stimulatory influence was not observed when their intake was restricted to a single oral dose " " ". Protein digestibility. Asafetida did not affect the digestibility of protein in sorghum " . ... 

In addition to LPL, human milk contains a bile salts-activated lipase, which probably contributes to the metabolism of lipids by breast-fed babies who have limited pancreatic lipase activity. Bovine milk and milks from other dairy animals do not contain this enzyme. 

Vantrappen GR, Rutgeerts PJ, et al. Mixed triglyceride breath test a noninvasive test of pancreatic lipase activity in the duodenum. Gastroenlerol-ogy 96 1126-1134,1989. 

Lessinger JM, Ferard G, Plasma pancreatic lipase activity from analytical specificity to clinical efficiency for the diagnosis of acute pancreatitis. Eur J Clin Chem Clin Biochem 1994 32 377-81. 

The C-mixed chain triglyceride test is designed as a test of intraluminal pancreatic lipase activity.The substrate for the test is 1,3-distearyl>2( carboxyl- C) octanoyl glycerol, which contains long chain fatty acids in positions 1 and 3 and the C-labeled medium chain fatty acid (octanoic acid) in position 2 (Figure 48-9). The labeled substrate is administered orally to fasting patients with a standard meal of toast and butter. Breath samples are collected over a 5-hour... 

There are similar issues when considering lipolysis of emulsions. Armand et ah (1992) found that pancreatic lipase activity was increased with decreasing emulsion size. However, modification of the interface of emulsions by heat treatment of the encapsulant (a mixture of caseinate and modified starch) prior to emulsion formation altered the rate of lipolysis of emulsions in model systems (Chung et al., 2008). The structuring of interfaces for the target delivery of oils and oil-soluble bioactives is currently an active field of research (Singh et ah, 2009). 

Larsson A and Erlansonalbertsson C. The Effect of Pancreatic Procolipase and Colipase on Pancreatic Lipase Activation. Biochim Biophys Acta 1991 1083 283-288. 

Panteghini M, Bonora R, Pagani F. Measurement of pancreatic lipase activity in serum by a kinetic colorimetric assay using a new chromogenic substrate. Aim Clin Biochem 2001 38 365-70. 

It is well known that dietary fat is not absorbed from the intestine unless it has been subjected to the action of pancreatic lipase [1], Previously, we found that basic proteins such as protamines, histones and purothionine inhibited the hydrolysis of triolein emulsified with phosphatidylcholine [2], The inhibition of hydrolysis of dietary fat may cause a decrease or delay in the intestinal absorption of fat and reduce blood chylomicron levels, an excess of which is known to induce obesity [3], Therefore, there was a possibility that inhibitory substances toward pancreatic lipase activity may prevent the onset of obesity induced by feeding a high fat diet to mice. Recently, we found that natural products such as tea saponin, platycodi radix saponin, chitin-chitosan and chondroitin sulfate inhibited the pancreatic lipase activity. In the following section, the anti-obesity effects of these natural products will be described in detail. 

Fig. (2). Effects of the water extract of oolong tea on pancreatic lipase activity. Values are expressed as mean + s.e.m. of four experiments. FFA=free fatty acid.

Fig. (3) Effects of tea saponin on pancreatic lipase activity. Results are expressed as means- s.e.m. offour experiments.

It was demonstrated that the anti-obesity effects of oolong tea in high-fat diet-treated mice might be partly due to the inhibitory actions of the saponin fraction in oolong tea on pancreatic lipase activity. In this study, tea saponin prevented the high-fat diet-induced increases in body and parametrial adipose tissue weights by inhibiting the intestinal absorption of dietary fat via inhibition of pancreatic lipase activity, Fig. (5). 

The aqueous extract of Platycodi radix inhibited the pancreatic lipase activity in a dose-dependent manner in the assay system using triolein emulsified with phosphatidylcholine, Fig. (6). At 2, 3 and 4 h after the administration of the aqueous extract of Platycodi radix, the plasma triacylglycerol concentration was significantly lower in the treated rats than in the control group, Fig. (7). 

It has been reported that various saponins isolated from foodstuffs have anti-obesity or hypolipidaemic actions [12-16], We found that the crude saponin fractions isolated from Platycodi radix strongly inhibited the pancreatic lipase activity, Fig. (10). 

As shown in Fig. (11a), chitin-chitosan inhibited the pancreatic lipase activity dose-dependently between the concentrations of 6.25 p,g/ml and 200 ig/ml in the assay system, using triolein emulsified with lecithin. For characterization of the mechanism involved in the inhibition of pancreatic lipase by chitin-chitosan, the enzyme activity was assayed at various concentrations of lecithin-emulsified triolein and in the presence of increasing concentrations of chitin-chitosan. A Lineweaver-Burk plot of the data in Fig. (11 b) shows that chitin-chitosan was a competitive inhibitor. The Km and Vmax values of the lipase activity for lecithin-emulsified triolein were 6.06 ag/ml and 8.7 nmol/ml/min, respectively. The K value of chitin-chitosan on the lipase activity in lecithin-emulsified triolein was 17.6 M-g/ml. When triolein was emulsified with... 

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