• Natural Product Sciences
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• v.9 no.1
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• pp.38-43
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• 2003

Pancreatic lipase-inhibitory activity of the rhizome of Rhei Rhizoma and its antihyperlipidemic activity were measured. Rhei Rhizoma inhibited pancreatic lipase with $IC_{50}$ value of 6.5 mg/ml (triolein as a substrate). Rhei Rhizoma significantly inhibited serum TG level in corn oil feeding-induced mice, and serum TG and cholesterol in Triton WR-1339-induced hyperlipidemic mice. However, Rhei Rhizoma did not show the hypolipidemic activity in high cholesterol diet-induced hyperlipidemic mice. When in vitro pancreatic lipase-inhibitory and in vivo antihyperlipidemic activities of Whangryunhaedoktang (WT) and Chunghyuldan (CD), which is consisted of ingredients of WT and Rhei Rhizoma, were measured, CD exhibited more potent inhibitory activities than WT. Therefore these results suggest that antihyperlipidemic activity of Rhei Rhizoma and CD may be more or less originated from the inhibition of pancreatic lipase.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.180-185
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• 2005

In the process of investigating anti-obesity effect of Platycodi Radix, we found that aqueous extract of Platycodi Radix might inhibit intestinal absorption of dietary fat by inhibiting pancreatic lipase (PL) activity. In order to clarify the anti-obesity mechanism of Platycodi Radix, activity-guided isolation was performed to find active components. The total saponin fraction of Platycodi Radix appeared to have a potent inhibitory activity against the hydrolysis of triolein emulsified with phosphatidycholine by pancreatic lipase in vitro. Based on these results, further purification of active components yielded 10 known triterpenoidal saponins, among these compounds, platycodin A, C, D, and deapioplatycodin D exhibited significant inhibitory effects on PL at the concentration of $500\;{\mu}g/mL$ with 3.3, 5.2, 34.8, and $11.67\%$ pancreatic lipase activity vs control, respectively. Platycodin D was found to inhibit the PL activity in a dose-dependent manner. Therefore, the anti-obesity effect of Platycodi Radix might be due to the inhibition of pancreatic lipase by its saponins.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.112-118
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• 2013

This study was performed to investigate the possible use of Eisenia bicyclis (EB) ethanol extract to inhibit activity against lipase. In tests, the lipase inhibitory activity of EB ethanol extract was noted as being 43, 27, and 24% at concentrations of 5, 2.5, and 1 mg/ml, respectively. Isolation was carried out by liquid and liquid extraction, silica-gel column chromatography, and HPLC. The results showed that the lipase inhibitory activity of the ethyl acetate (EA) fraction from EB ethanol extract exhibited the strongest lipase inhibitory activity with an $IC_{50}$ value of 1.31 mg/ml. The EA fraction was separated using silica-gel column chromatography and we obtained 22 sub-fractions. Amongst them, the EA1 fraction showed the highest lipase inhibitory activity with an $IC_{50}$ value of 0.54 mg/ml. Eight peaks were obtained from the EA1 fraction by HPLC. Fraction 5 also showed a strong lipase inhibitory activity with an $IC_{50}$ value of 0.37 mg/ml. The fraction 5 was identified as dieckol and the inhibition pattern analyzed from Lineweaver-Burk plots revealed a non-competitive inhibitor. These results suggest that EB has potential as a natural anti-obesity agent.

• Food Science of Animal Resources
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• v.30 no.5
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• pp.764-772
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• 2010

Staphylococcus aureus lipase is regarded as a virulence factor. The response of lipase activity to various factors can provide important insights concerning the prevention of S. aureus during meat fermentation. This study was conducted to evaluate the main effects of nutrients used in culture media, and their combined effects on the inhibition of lipase activity and cell growth of pathogenic S. aureus SK1593 isolated from fermented pork meat. A Plackett-Burman design was used to evaluate the main effects of variables, including olive oil, soybean oil, grapeseed oil, sesame oil, $CuSO_4$, $MgCl_2$, $KNO_3$, $CaCl_2$, and KCl. Significant negative effects on lipase activity were detected with soybean oil, grapeseed oil, $KNO_3$, and $CaCl_2$. Additionally, these nutrients were further selected as variables for the investigation of their combined effect on lipase activity, via response surface methodology. In order to confirm the regression model, a situation that only inhibits lipase activity was simulated. The predicted lipase activity and cell growth of the simulated situation were 14.0 U/mL and $9.6\;{\log}_{10}$ (CFU/mL), respectively, and the estimated value of those in the same medium showed 15.14 U/mL and $9.4\;{\log}_{10}$(CFU/mL) respectively. The lipase activity of the simulated medium was inhibited approximately 5-fold as compared to the basal medium, but no significant differences in cell counts were noted to exist between the basal and simulated media. These results suggest that soybean oil, grapeseed oil, $KNO_3$, and $CaCl_2$ can be used to inhibit the growth of pathogenic S. aureus during the process of meat fermentation.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.315-322
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• 2014

Immobilized lipases were prepared by physical adsorption using lipase AK, AY, AH, PS and R on Amberlite$^{(R)}$XAD$^{(R)}$7 HP resin. With the immobilized lipases (10%), structured lipid was synthesized by enzymatic interesterification of canola oil, palmitic ethyl ester, and stearic ethyl ester in order to study the reaction characteristics. Among the lipase, the highest protein content was obtained from lipase AH (11.41%) before immobilization, while the highest levels of bound protein was observed from immobilized lipase AK (63.91%). Immobilized lipase AK had the highest interesterification activity (38.3% of total saturated fatty acid). Lipase AK was also used for a continuous reaction in which the slow flow of reactant resulted in increased reaction rate. Reusability of immobilized AK, AH and PS increased at the second reaction (120-196.5%). However, the activity of immobilized AK, which had the highest bound protein content (63.91%) decreased after the third reaction, while the activity of immobilized AH and PS was maintained until the sixth reaction.

• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.196-205
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• 2020

In this study, the acidic lipase from Aspergillus niger (ANL) was homologously expressed in A. niger. The expression of ANL was significantly improved by the expression of the native ANL with the introns, the addition of the Kozak sequence and the optimization of the signal sequences. When the cDNA sequence of ANL fused with the glaA signal was expressed under the gpdA promoter in A. niger, no lipase activity could be detected. We then tried to improve the expression by using the full-length ANL gene containing three introns, and the lipase activity in the supernatant reached 75.80 U/ml, probably as a result of a more stable mRNA structure. The expression was further improved to 100.60 U/ml by introducing a Kozak sequence around the start codon due to a higher translation efficiency. Finally, the effects of three signal sequences including the cbhI signal, the ANL signal and the glaA signal on the lipase expression were evaluated. The transformant with the cbhI signal showed the highest lipase activity (314.67 U/ml), which was 1.90-fold and 3.13-fold higher than those with the ANL signal and the glaA signal, respectively. The acidic lipase was characterized and its highest activity was detected at pH 3.0 and a temperature of 45℃. These results provided promising strategies for the production of the acidic lipase from A. niger.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.63-67
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• 2004

A simple procedure for the extraction of the lipolytic enzyme from rice bran has been developed. High activity of lipolytic enzyme was obtained by first defatting the rice bran to remove lipid components with various extraction conditions. Then, after rove cycles of aqueous extraction, rice bran lipolytic enzyme was purified using micro- and ultrafiltration apparatus. Lipolytic enzyme activity was estimated by its hydrolytic action of tributyrin. The result indicated that the standard activity curve of butyric acid showed that the potential rice bran enzyme is a hydrolytic lipase enzyme. In addition, it showed higher lipolytic activity and specific enzyme activity with further purification by micro- and ultrafiltration. The size of rice bran lipase enzyme was identified through 15 ％ SDS-PAGE. The molecular weight of the rice bran lipase enzyme was 41 kDa.

• Natural Product Sciences
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• v.18 no.3
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• pp.153-157
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• 2012

Obesity, which is characterized by excessive fat accumulation in adipose tissues, occurs by fat absorption by lipase and sequential fat accumulation in adipocyte through adipocyte differentiation. Thus, inhibition of pancreatic lipase activity and adipocyte differentiation would be crucial for the prevention and progression of obesity. In the present study, we attempted to evaluate anti-adipogenic activity of several algae extracts employing preadipocytes cell line, 3T3-L1 as an in vitro assay system. The effects on pancreatic lipase activity in vitro were also evaluated. Total methanolic extracts of Cladophora wrightiana and Costaria costata showed significant inhibitory activity on adipocyte differentiation as assessed by measuring fat accumulation using Oil Red O staining. Related to pancreatic lipase, C. wrightiana and Padina arborescens showed significant inhibition. Further fractionation of C. wrightiana, which showed the most potent activity, suggested that $CHCl_3$ and n-BuOH fraction are responsible for adipocyte differentiation inhibition, whereas n-BuOH and $H_2O$ fraction for pancreatic lipase inhibition. Our study also demonstrated that n-BuOH fraction was effective both in early and middle stage of differentiation whereas $CHCl_3$ fraction was effective only in early stage of differentiation. Taken together, algae might be new candidates in the development of obesity treatment.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.491-505
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• 2020

A newly isolated strain, Proteus vulgaris OR34, from olive mill waste was found to secrete an alkaline extracellular lipase at 11 U·ml-1 when cultivated on an optimized liquid medium. This lipase was purified 94.64-fold with a total yield of 9.11% and its maximal specific activity was shown to be 3232.58 and 1777.92 U·mg-1 when evaluated using the pH-stat technique at 55℃ and pH 9 and Tributyrin TC4 or olive oil as the substrate. The molecular mass of the pure OR34 lipase was estimated to be around 31 kDa, as revealed by SDS-PAGE and its substrate specificity was investigated using a variety of triglycerides. This assay revealed that OR34 lipase preferred short and medium chain fatty acids. In addition, this lipase was stable in the presence of high concentrations of bile salt (NaDC) and calcium ions appear not to be necessary for its activity. This lipase was inhibited by THL (Orlistat) which confirmed its identity as a serine enzyme. In addition, the immobilization of OR34 lipase by adsorption onto calcium carbonate increased its stability at higher temperatures and within a larger pH range. The immobilized lipase exhibited a high tolerance to organic solvents and retained 60% of its activity after 10 months of storage at 4℃. Finally, the OR34 lipase was applied in biodiesel synthesis via oleic acid mediated esterification of methanol when using hexane as solvent. The best conversion yield (67%) was obtained at 12 h and 40℃ using the immobilized enzyme and this enzyme could be reused for six cycles with the same efficiency.

• Macromolecular Research
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• v.12 no.6
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• pp.586-592
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• 2004

Poly(glycidyl methacrylate)-grafted polyethylene microbeads (POPM) presenting epoxy groups were prepared by radiation-induced graft polymerization of glycidyl methacrylate on the polyethylene microbead. The obtained POPM was characterized by IR spectroscopic, X-ray photoelectrons spectroscopy (XPS), scanning electron microscope (SEM), and thermal analyses. Furthermore, the abundance of epoxy groups on the POPM was determined by titration and elemental analysis after amination. The epoxy group content was calculated to be in the range 0.29-0.34 mmol/g when using the titration method, but in the range 0.53-0.59 mmol./g when using elemental analysis (EA) after amination. The lipase was immobilized to the epoxy groups of the POPM under various experi­mental conditions, including changes to the pH and the epoxy group content. The activity of the lipase-immobilized POPM was in the range from 160 to 500 unit/mg-min. The activity of the lipase-immobilized POPM increased upon increasing the epoxy group content. The lipase-immobilized POPM was characterized additionally by SEM, elec­tron spectroscopy for chemical analysis (ESCA), and EA.