Direct Measurement of Lipase Inhibition by Orlistat Using a Dissolution Linked In Vitro Assay

Lewis, Daniel R.; Liu, Dongzhou J.

doi:10.4172/2167-065x.1000103

Cited by 36 publications

(25 citation statements)

References 15 publications

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“…It should be noted, on the other hand, that the general kinetics and K M values of lipases can be expected to vary considerably depending on the way in which the lipophilic substrate is solubilized and the general conditions of the assay. A K M of 2.7 μM has been reported, for example, for pancreatic lipase hydrolyzing the same substrate used in the present work, but in a medium containing 5 mM sodium deoxycholate in addition to 10% isopropanol and 50 mM phosphate buffer at pH 8.0 [ 18 ].…”

Section: Resultsmentioning

confidence: 78%

Inhibition of Pancreatic Lipase and Triacylglycerol Intestinal Absorption by a Pinhão Coat (Araucaria angustifolia) Extract Rich in Condensed Tannin

et al. 2015

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The purpose of the present work was to characterize the possible inhibition of pancreatic lipase by a tannin-rich extract obtained from the pinhão (Araucaria angustifolia seed) coat, based on the previous observation that this preparation inhibits α-amylases. Kinetic measurements of pancreatic lipase revealed that the pinhão coat tannin is an effective inhibitor. Inhibition was of the parabolic non-competitive type. The inhibition constants, trueK¯i1 and trueK¯i2, were equal to 332.7 ± 146.1 μg/mL and 321.2 ± 93.0 μg/mL, respectively, corresponding roughly to the inhibitor concentration producing 50% inhibition ([I]50). Consistently, the pinhão coat extract was also effective at diminishing the plasma triglyceride levels in mice after an olive oil load; 50% diminution of the area under the plasma concentration versus the time curve occurred at a dose of 250 mg/kg. This observation is most probably the consequence of an indirect inhibition of triglyceride absorption via inhibition of pancreatic lipase. For the pinhão coat tannin, this is the second report of a biological activity, the first one being a similar inhibition of the absorption of glucose derived from starch as a consequence of an inhibitory action on α-amylases. Taken together, these effects represent a potential anti-obesity action, as suggested for other polyphenol or tannin-rich preparations.

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Section: Resultsmentioning

confidence: 78%

Inhibition of Pancreatic Lipase and Triacylglycerol Intestinal Absorption by a Pinhão Coat (Araucaria angustifolia) Extract Rich in Condensed Tannin

et al. 2015

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“…Lipase preparation: The crude PPL was dissolved in 50 mM phosphate buffer pH 7 (1 mg/ml) and centrifuged at 12 000 x g for 5 min to remove all insoluble [15,16]. Enzyme stock concentration was set at approximately 0.1 mg/ml for every 1 mg solid PPL powder dissolved in 1 ml of buffer.…”

Section: Lipase Inhibition Assaymentioning

confidence: 99%

“…The ability of the compounds to inhibit PPL was measured using the modified method previously reported by Lewis [16]. The lipase activity was determined by measuring the hydrolysis of pNPB to p-nitrophenol at 405 nm using UV-transparent 96-well plates on an ELISA reader (BIO-TEK, Synergy HT, USA) Lipase assays were performed by incubating the plant extracts (final concentration of 500 µg/ml) with PPL and pNPB in reaction buffer (50 mM potassium phosphate buffer, pH 7.2, 0.5% Triton X-100) for 10 min.…”

Section: Lipase Inhibition Reactionmentioning

confidence: 99%

Anti-obesity Potential of Selected Tropical Plants via Pancreatic Lipase Inhibition

Alias¹,

Leow²,

Ali³

et al. 2017

AOWMC

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Natural products are a vast source of potential compounds that can be developed as anti-obesity agent. One of the mechanisms of anti-obesity agents is inhibition of pancreatic lipase. Assay of 24 crude extracts for their in vitro activity against porcine pancreatic lipase (PPL) detected four extracts demonstrating high (>70%) inhibition, seven extracts had medium (30-70%) inhibition and the remaining 13 extracts exhibited low (<30%) inhibition when incubated with PPL at a concentration of 500 µg/ml for 10 min at 37°C. Phyllanthus niruri extract displayed the most potent PPL inhibitor, followed by Orthosiphon stamineus, Murraya paniculata and Averrhoa bilimbi with the IC50 value of 27.7<34.7< 41.5<55.2 µg/ml, respectively. P. niruri & O. stamineus (the best two extracts) showed noncompetitive and uncompetitive inhibition, respectively. P. niruri & O. stamineus displayed total phenolic content of 431.0 ± 0.01 and 103.0 ± 0.01 mg GAE/g dry extract, while total flavonoid content of 14.8 ± 0.07 and 21.6 ± 0.03 mg QE/g dry extract, respectively. Both P. niruri & O. stamineus extracts showed high antioxidant activity, with EC50 values of 8.4 and 26.3 µg/ml, respectively. The results suggest that P. niruri & O. stamineus may be beneficial for obesity treatment via pancreatic lipase inhibition action.

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“…The activity of lipase was measured using p-nitrophenyl palmitate (NPhP) as a substrate in 0.5 μM of PPL [31]. Five millimeter of NPhP was taken in 10 mM phosphate buffer without any denaturant, and the solution was kept at 25°C using the Peltier attached to the spectrophotometer.…”

Section: Activity Studiesmentioning

confidence: 99%

Stability and Activity of Porcine Lipase Against Temperature and Chemical Denaturants

Chaitanya

Prabhu

2014

Appl Biochem Biotechnol

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Lipases are the class of hydrolases with wide industrial applications. The present study analyses the stability of porcine pancreatic lipase (PPL) against urea, guanidine hydrochloride (Gdn), sodium dodecyl sulphate (SDS), and temperature using different spectroscopic techniques. Interestingly, this two-domain protein shows a two-state unfolding transition against urea and Gdn. The free energy of unfolding of PPL calculated from global analysis of the unfolding transitions obtained from different spectroscopic techniques is ~2.2 kcal/mol. In the presence of SDS, PPL shows a cooperative loss of secondary and tertiary structures above 0.2 mM of SDS. At above 2 mM of SDS, PPL forms irreversible, non-native, thermally stable structure. PPL loses its activity even at lower concentrations of urea (3 M), Gdn (0.5 M), and SDS (0.8 mM). Thermal denaturation of PPL shows an irreversible unfolding, and the protein lost its activity even by increasing the temperature to 45 °C. Though PPL in higher concentrations of SDS (>5 mM) shows stable conformation against temperature, its activity is completely lost. The results suggest that the structure and activity of PPL are more sensitive against chemical denaturants and temperature, and forms irreversible, non-native (in SDS) or completely unfolded (in urea, Gdn, and at higher temperature) conformations in different denaturing conditions.

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Direct Measurement of Lipase Inhibition by Orlistat Using a Dissolution Linked In Vitro Assay

Cited by 36 publications

References 15 publications

Inhibition of Pancreatic Lipase and Triacylglycerol Intestinal Absorption by a Pinhão Coat (Araucaria angustifolia) Extract Rich in Condensed Tannin

Inhibition of Pancreatic Lipase and Triacylglycerol Intestinal Absorption by a Pinhão Coat (Araucaria angustifolia) Extract Rich in Condensed Tannin

Anti-obesity Potential of Selected Tropical Plants via Pancreatic Lipase Inhibition

Stability and Activity of Porcine Lipase Against Temperature and Chemical Denaturants

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