Inhibition of lipid absorption as an approach to the treatment of obesity

Fermented Oats as a Novel Functional Food

Fermented oats are gaining popularity due to their nutritional value and the increasing consumer demand for health-conscious foods. These oats are believed to offer enhanced phytochemical and nutritional profiles compared to unfermented oats. The increased nutritional content of fermented oats is associated with various health benefits, including anti-inflammatory and antioxidant activities, which could potentially reduce the risk of chronic diseases. Further investigations are warranted to elucidate the nutritional benefits of fermented oats in human nutrition. This mini review provides a comprehensive overview of fermented oat products available on the market and the various production methods employed for fermenting oats. Furthermore, this review investigates how fermentation affects the chemical composition and biological functions of oats. Additionally, this manuscript presents some future perspectives on fermented oat products by discussing potential research directions and opportunities for further development. The findings presented in this review contribute to the expanding body of knowledge on fermented oats as a promising functional food, paving the way for future studies and applications in the field of nutrition and health.

Methodologies for Assessing Pancreatic Lipase Catalytic Activity: A Review

Obesity is a disease of epidemic proportions with a concerning increasing trend. Regarded as one of the main sources of energy, lipids can also represent a big part of an unnecessary intake of calories and be, therefore, directly related to the problem of obesity. Pancreatic lipase is an enzyme that is essential in the absorption and digestion of dietary fats and has been explored as an alternative for the reduction of fat absorption and consequent weigh loss.Literature describes a great variability of methodologies and experimental conditions used in research to evaluate the in vitro inhibitory activity of compounds against pancreatic lipase. However, in an attempt to choose the best approach, it is necessary to know all the reaction conditions and understand how these can affect the enzymatic assay.The objective of this review is to understand and summarize the methodologies and respective experimental conditions that are mainly used to evaluate pancreatic lipase catalytic activity.156 studies were included in this work and a detailed description of the most commonly used UV/Vis spectrophotometric and fluorimetric instrumental techniques are presented, including a discussion regarding the differences found in the parameters used in both techniques, namely enzyme, substrate, buffer solutions, kinetics conditions, temperature and pH.This works shows that both UV/Vis spectrophotometry and fluorimetry are useful instrumental techniques for the evaluation of pancreatic lipase catalytic activity, presenting several advantages and limitations, which make the choice of parameters and experimental conditions a crucial decision to obtain the most reliable results.

Lactobacillus plantarum KFY04 prevents obesity in mice through the PPAR pathway and alleviates oxidative damage and inflammation

In this study, lactic acid bacterium, Lactobacillus plantarum KFY04, was isolated from Xinjiang yogurt, and it was used to intervene in obese mice maintained on a 45% fat diet, and we compared its effects to those of a commercial strain, LDSB, and l-carnitine. The results showed that the LP-KFY04 intervention mice gained weight more slowly and had lower liver, epididymal adipose, and perirenal adipose tissue indices when compared to the other high-fat groups. Moreover, the LP-KFY04 can reduce the formation of fat vacuoles in the liver, while also reducing adipocyte differentiation and volume, and LP-KFY04 groups had the lowest liver and serum AST, ALT, TG, and TC levels and lowest serum LDL-C and highest HDL-C levels among the groups maintained on a high-fat diet. LP-KFY04 was also shown to mitigate obesity-associated oxidative damage and inflammatory responses. Additionally, quantitative real-time PCR and western blot analysis examining liver and adipose tissue expression of PPAR-α, CYP7A1, CPT1, and LPL showed an increased expression in the LP-KFY04 groups while decreased expression levels of PPAR-γ and C/EBPα relative to the other high-fat diet groups. These results show that of the different interventions, LP-KFY04 was the most effective at mitigating the effects of obesity than LDSB and l-carnitine. The results confirmed that LP-KEY04 has better anti-obesity, anti-oxidative, and anti-inflammatory effects than current fermentation strains. It indicates LP-KFY04 is a fermentation strain with potential practical value and high functionality, and it shows that a fermentation strain should not only have good fermentation performance, but, more importantly, it must provide more functionality on the basis of fermentation.

Downy Lavender Oil: A Promising Source of Antimicrobial, Antiobesity, and Anti-Alzheimer's Disease Agents

Lavandula pubescens Decne (LP) is one of the three Lavandula species growing wildly in the Dead Sea Valley, Palestine. The products derived from the plant, including the essential oil (EO), have been used in Traditional Arabic Palestinian Herbal Medicine (TAPHM) for centuries as therapeutic agents. The EO is traditionally believed to have sedative, anti-inflammatory, antiseptic, antidepressive, antiamnesia, and antiobesity properties. This study was therefore aimed to assess the in vitro bioactivities associated with the LP EO. The EO was separated by hydrodistillation from the aerial parts of LP plants and analyzed for its antioxidant, antimicrobial, anticholinesterase, and antilipase activities. GC-MS was used for phytochemical analysis. The chemical analysis of the EO composition revealed 25 constituents, of which carvacrol (65.27%) was the most abundant. EO exhibited strong antioxidant (IC₅₀ 0.16–0.18 μL/mL), antiacetylcholinesterase (IC₅₀ 0.9 μL/mL), antibutyrylcholinesterase (IC₅₀ 6.82 μL/mL), and antilipase (IC₅₀ 1.08 μL/mL) effects. The EO also demonstrated high antibacterial activity with the highest susceptibility observed for Staphylococcus aureus with 95.7% inhibition. The EO was shown to exhibit strong inhibitory activity against Candida albicans (MIC 0.47 μL/mL). The EO was also shown to possess strong antidermatophyte activity against Microsporum canis, Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum (EC₅₀ 0.05–0.06 μL/mL). The high antioxidant, enzyme inhibitory, and antimicrobial potentials of the EO can, therefore, be correlated with its high content of monoterpenes, especially carvacrol, as shown by its comparable bioactivities indicators results. This study provided new insights into the composition and bioactivities of LP EO. Our finding revealed evidence that LP EO makes a valuable natural source of bioactive molecules showing substantial potential as antioxidant, neuroprotective, antihyperlipidemic, and antimicrobial agents. This study demonstrates, for the first time, that LP EO might be useful for further investigation aiming at integrative CAM and clinical applications in the management of dermatophytosis, Alzheimer's disease, and obesity.

Synthesis and Pancreatic Lipase Inhibitory Activity of Phenacyl Esters of N-Aroyl Amino Acids

Background:

Obesity has become a major life-threatening disorder as it is associated with many risk factors such as coronary heart disease, hypertension, type II diabetes and certain forms of cancer. Pancreatic lipase inhibition is one of the alternate strategies to treat obesity. In our previous study, phenacyl ester of N-sulphonyl beta alanine was obtained as a hit molecule when pharmacophore- based virtual screening was carried out using reported pancreatic lipase inhibitors.

Objective:

In search of novel pancreatic lipase inhibitors, three series of phenacyl esters of Nsubstituted amino acids were synthesized and evaluated for their pancreatic lipase inhibitory activity.

Methods:

N-aroylation of amino acids and subsequent esterification with different phenacyl bromides in the presence of N,N-Dimethylformamide (DMF) afforded the corresponding phenacyl esters in quantitative yields.

Results:

The synthesized compounds were found to have good pancreatic lipase inhibitory activity and showed IC50 in the range of 0.036 and 84 μg/ml.

Conclusion:

All the synthesized compounds showed better pancreatic lipase inhibitory activity and it indicates that the N-aroylated phenacyl esters could be considered as lead moiety for further studies to develop novel anti-obesity potentials.

Cyanidin and cyanidin-3-glucoside derived from Vigna unguiculata act as noncompetitive inhibitors of pancreatic lipase

The consumption of legumes positively correlated with the reduction of body weight. In the present study, we identified and evaluated pancreatic lipase inhibitors from Vigna unguiculata and unraveled their mode of inhibition. The highly sensitive fluorometric method was adopted to access the pancreatic lipase activity and the ethanolic extract of Vigna unguiculata showed the maximum inhibition (IC₅₀ of 15.2 µg/ml). Cyanidin and cyanidin-3-glucoside are the major anthocyanins observed in Vigna unguiculata. The IC₅₀ value of cyanidin was 28.29 µM which was 6.5-fold higher than the cyanidin-3-glucoside (188.28 µM). We determined an apparent K_i of 27.28 µM for cyanidin and cyanidin-3-glucoside (88.97 µM) with noncompetitive inhibition. Collectively, these results suggest that the glycosylation of the anthocyanidins significantly reduces lipase inhibition. The noncompetitive inhibition of pancreatic lipase by Vigna unguiculata anthocyanins may exert significant pharmacological activities toward obesity complications by calorie restriction. PRACTICAL APPLICATIONS: The results of this study emphasize the importance of legumes in our diet to combat obesity-related complications. Consumption of legumes minimizes fat absorption by inhibiting the action of the fat-digesting enzyme.

Proteinaceous Pancreatic Lipase Inhibitor from the Seed of Litchi chinensis

A study of the pancreatic lipase inhibitory activity of a protein from the seed of Litchi chinensis was carried out. Protein was isolated by 70% ammonium sulphate precipitation followed by dialysis. Lipase inhibitory activity of the protein was evaluated using both synthetic (p-nitrophenyl palmitate) and natural (olive oil) substrates. Protein at the final concentration of 100 µg/mL was able to inhibit 68.2% pancreatic lipase on synthetic substrate and 60.0% on natural substrate. Proteinaceous nature of the inhibitor was determined using trypsinization assay. Pancreatic lipase inhibitory protein was sensitive to 0.05% trypsin treatment with the loss of 61.9% activity. IC₅₀ of this proteinaceous pancreatic lipase inhibitor was 73.1 µg/mL using synthetic substrate. This inhibitory protein was sensitive to pH, with the highest inhibitory activity at pH=8.0 and the lowest at pH=3.0. Protein was further analyzed using 10% non-reducing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and, interestingly, it showed the presence of a single band of (61±2) kDa when stained with Coomassie brilliant blue. The isolated protein was finally crystallized to see its homogeneity by batch crystallization method. Crystals were well formed with distinct edges. The isolated protein showed good pancreatic lipase inhibitory activity.

Intestinal Saturated Long-Chain Fatty Acid, Glucose and Fructose Transporters and Their Inhibition by Natural Plant Extracts in Caco-2 Cells

The intestinal absorption of fatty acids, glucose and fructose is part of the basic requirements for the provision of energy in the body. High access of saturated long-chain fatty acids (LCFA), glucose and fructose can facilitate the development of metabolic diseases, particularly the metabolic syndrome and type-2 diabetes mellitus (T2DM). Research has been done to find substances which decelerate or inhibit intestinal resorption of these specific food components. Promising targets are the inhibition of intestinal long-chain fatty acid (FATP2, FATP4), glucose (SGLT1, GLUT2) and fructose (GLUT2, GLUT5) transporters by plant extracts and by pure substances. The largest part of active components in plant extracts belongs to the group of polyphenols. This review summarizes the knowledge about binding sites of named transporters and lists the plant extracts which were tested in Caco-2 cells regarding uptake inhibition.

Use of Simplified Molecular Input Line Entry System and molecular graph based descriptors in prediction and design of pancreatic lipase inhibitors

Aim: The inhibition of pancreatic lipase (PL) enzyme is the most explored strategy for the treatment of obesity. The present study describes the development of quantitative structure–activity relationship (QSAR) models for a diverse set of 293 PL inhibitors by means of the Monte Carlo optimization technique. Methodology & results: The hybrid optimal descriptors were used to build QSAR models with three subsets of three splits. The developed QSAR models were further validated with corresponding external sets. The best QSAR model has the following statistical particulars: R2 = 0.752, Q LOO 2 = 0 . 736 for the test set and R2 = 0.768, Q F 1 2 = 0 . 628 , Q F 2 2 = 0 . 621 for the validation set. Conclusion: The developed QSAR models were robust, stable and predictive and led to the design of novel PL inhibitors.

Antiobesity and Antioxidant Potentials of Selected Palestinian Medicinal Plants

We evaluated the antioxidant and porcine pancreatic lipase inhibition (PPLI) activities of 90 plants extracts. The antioxidant activity was measured using the free-radical scavenging capacity (DPPH) and reducing power (RP) assays. The pancreatic lipase inhibition assay was used to determine the PPLI activity of plant extracts. Among the 90 plant extracts examined, 41.0 % crude extracts showed antilipase activity of more than 50%. The most active plants by means of IC₅₀ value were Camellia sinensis (0.5 mg/ml), Ceratonia siliqua (leaves) (0.8 mg/mL), Curcuma longa (0.8 mg/mL), Sarcopoterium spinosum (1.2 mg/mL), and Mentha spicata (1.2 mg/mL). The antioxidant activity of plant extracts using the DPPH and RP assays reveals comparable results. The most active antioxidant extracts using both assays were the leaves and fruit epicarp of Rhus coriaria, areal parts of Sarcopoterium spinosum, and leaves of Ceratonia siliqua. Our results suggest natural resources that possess strong antioxidant and pancreatic lipase inhibitory activities with potential applications in the treatment and prevention of obesity and overweight. The extracts of Camellia sinensis, Ceratonia siliqua, Curcuma longa, Sarcopoterium spinosum, and Mentha spicata were proved to have a great potential as antioxidants and antiobesity agents.

Evaluation of the stability of tyrosol esters during in vitro gastrointestinal digestion

Lipophenols such as tea polyphenol palmitate derivatives (palmitoyl esters of tea polyphenols) have been classified as non-toxic food additives due to their better protective effects on lipidic food matrices from oxidation, but their digestion and absorption have remained unexplored.

Saponin-enriched sea cucumber extracts exhibit an antiobesity effect through inhibition of pancreatic lipase activity and upregulation of LXR-β signaling

CONTEXT

Sea cucumbers have been consumed as tonic, food, and nutrition supplements for many years.

OBJECTIVE

The objective of this study is to investigate the antiobesity and lipid-lowering effects of sea cucumber extracts in in vitro and in vivo models and elucidate the mechanism of action of the extracts on obesity and dyslipidemia.

MATERIALS AND METHODS

The 60% ethanol extracts from the body walls of 10 different sea cucumbers were investigated for the inhibition of pancreatic lipase (PL) activity in vitro. The optimal active extract (SC-3) was further chemically analyzed by LC-MS and UV. And 0.1% and 0.2% of SC-3 was mixed with a high-fat diet to treat C57/BL6 mice for 6 weeks or 2 weeks as preventive and therapeutic study. The body weight, serum, and liver lipid profile in the mice were investigated.

RESULTS

The crude extract of Pearsonothuria graeffei Semper (Holothuriidae) inhibited the PL activity by 36.44% of control at 0.5 μg/mL. SC-3 and echinoside A inhibited PL with an IC50 value at 2.86 μg/mL and 0.76 μM. 0.1% of SC-3 reduced the body weight (23.0 ± 0.62 versus 26.3 ± 0.76 g), the serum TC (2.46 ± 0.04 versus 2.83 ± 0.12 mmol/L), TG (0.19 ± 0.08 versus 0.40 ± 0.03 mmo/L), and LDL-c (0.48 ± 0.02 versus 0.51 ± 0.02 mmol/L), and liver TC (1.19 ± 0.17 versus 1.85 ± 0.13 mmol/mg) and TG (6.18 ± 0.92 versus 10.87 ± 0.97 mmol/mg) contents of the obese C57BL/six mice on a high-fat diet.

DISCUSSION AND CONCLUSION

Sea cucumber may be used for developing antiobesity and antihyperlipidemia drugs.

Medicinal Plants Traditionally Used for Treatment of Obesity and Diabetes Mellitus - Screening for Pancreatic Lipase and α-Amylase Inhibition

In order to find new pancreatic lipase (PL) and α-amylase inhibitors from natural sources for the treatment of obesity and related diseases as diabetes mellitus II, 23 medicinal plants with weight-reducing, serum glucose-reducing or related potential were investigated. Methanolic and water extracts of the plants were evaluated by using two in vitro test systems. Our findings have shown that the methanolic extract of Hibiscus sabdariffa L. (Malvaceae) showed high inhibitory activities to PL (IC50 : 35.8 ± 0.8 µg/mL) and α-amylase (IC50 : 29.3 ± 0.5 µg/mL). Furthermore, the methanolic extract of Tamarindus indica L. (Leguminosae) showed a high anti-lipase (IC50 : 152.0 ± 7.0 µg/mL) and the aqueous extract a high anti-amylase (IC50 : 139.4 ± 9.0 µg/mL) activity. This work provides a priority list of interesting plants for further study with respect to the treatment of obesity and associated diseases.

High-throughput virtual screening with e-pharmacophore and molecular simulations study in the designing of pancreatic lipase inhibitors

BACKGROUND

Obesity is a progressive metabolic disorder in the current world population, and is characterized by the excess deposition of fat in the adipose tissue. Pancreatic lipase is one of the key enzymes in the hydrolysis of triglycerides into monoglycerides and free fatty acids, and is thus considered a promising target for the treatment of obesity. The present drugs used for treating obesity do not give satisfactory results, and on prolonged usage result in severe side effects. In view of the drastic increase in the obese population day-to-day, there is a greater need to discover new drugs with lesser side effects.

MATERIALS AND METHODS

High-throughput virtual screening combined with e-pharmacophore screening and ADME (absorption, distribution, metabolism, and excretion) and PAINS (pan-assay interference compounds) filters were applied to screen out the ligand molecules from the ZINC natural molecule database. The screened molecules were subjected to Glide XP docking to study the molecular interactions broadly. Further, molecular dynamic simulations were used to validate the stability of the enzyme-ligand complexes. Finally, the molecules with better results were optimized for in vitro testing.

RESULTS

The screening protocols identified eight hits from the natural molecule database, which were further filtered through pharmacological filters. The final four hits were subjected to extra precision docking, and the complexes were finally studied with molecular dynamic simulations. The results pointed to the zinc 85893731 molecule as the most stable in the binding pocket, producing consistent H-bond interaction with Ser152 (G=-7.18). The optimized lead molecule exhibited good docking score, better fit, and improved ADME profile.

CONCLUSION

The present study specifies zinc 85893731 as a lead molecule with higher binding score and energetically stable complex with pancreatic lipase. This lead molecule, along with its various analogs, can be further tested as a novel inhibitor against pancreatic lipase using in vitro protocols.

A review of the phytochemistry and pharmacological activities of raphani semen

The dried ripe seed of Raphanus sativus L., commonly known as radish seed (or Raphani Semen), is used as traditional Chinese medicine (TCM) to treat constipation, chronic tracheitis, and hypertension. The major active compounds in Raphani Semen are alkaloids, glucosinolates, brassinosteroids, and flavonoids. Fatty acids are its main nutritional contents. Raphani Semen has been demonstrated to have beneficial effects on hypertension, obesity, diabetes mellitus, constipation, and cough. So far, there is no report about the adverse/toxic effects of this herb on humans. However, Raphani Semen processed by roasting was reported to exhibit some adverse effects on mice. Additionally, erucic acid, the main fatty acid in Raphani Semen, was shown to enhance the toxicity of doxorubicin. Thus, Raphani Semen has a potential risk of causing toxicity and drug interaction. In summary, Raphani Semen is a valuable TCM herb with multiple pharmacological effects. More studies on Raphani Semen could help better understand its pharmacological mechanisms so as to provide clear scientific evidence to explain its traditional uses, to identify its therapeutic potential on other diseases, and to understand its possible harmful effects.

Anti-obesity effects of galangin, a pancreatic lipase inhibitor in cafeteria diet fed female rats

CONTEXT

Alpinia galanga Willd (Zingiberaceae) (AG) is a rhizomatous herb widely cultivated in shady regions of Malaysia, India, Indochina and Indonesia. It is used in southern India as a domestic remedy for the treatment of rheumatoid arthritis, cough, asthma, obesity, diabetes, etc. It was reported to have anti-obesity, hypoglycemic, hypolipidemic and antioxidant properties.

OBJECTIVE

A flavonol glycoside, galangin, was isolated from AG rhizomes. Based on its in vitro pancreatic lipase inhibitory effect, the study was further aimed to clarify whether galangin prevented obesity induced in female rats by feeding cafeteria diet (CD) for 6 weeks.

MATERIALS AND METHODS

The in vitro pancreatic lipase inhibitory effect of galangin was determined by measuring the release of oleic acid from triolein. For in vivo experiments, female albino rats were fed CD with or without 50 mg/kg galangin for 6 weeks. Body weight and food intake was measured at weekly intervals. On day 42, serum lipids levels were estimated and then the weight of liver and parametrial adipose tissue (PAT) was determined. The liver lipid peroxidation and triglyceride (TG) content was also estimated.

RESULTS

The IC50 value of galangin for pancreatic lipase was 48.20 mg/mL. Galangin produced inhibition of increased body weight, energy intake and PAT weight induced by CD. In addition, galangin produced a significant decrease in serum lipids, liver weight, lipid peroxidation and accumulation of hepatic TGs.

CONCLUSION

Galangin present in AG rhizomes produces anti-obesity effects in CD-fed rats; this may be mediated through its pancreatic lipase inhibitory, hypolipidemic and antioxidant activities.

Bioinformatic analysis of α/β-hydrolase fold enzymes reveals subfamily-specific positions responsible for discrimination of amidase and lipase activities

Superfamily of alpha-beta hydrolases is one of the largest groups of structurally related enzymes with diverse catalytic functions. Bioinformatic analysis was used to study how lipase and amidase catalytic activities are implemented into the same structural framework. Subfamily-specific positions--conserved within lipases and peptidases but different between them--that were supposed to be responsible for functional discrimination have been identified. Mutations at subfamily-specific positions were used to introduce amidase activity into Candida antarctica lipase B (CALB). Molecular modeling was implemented to evaluate influence of selected residues on binding and catalytic conversion of amide substrate by corresponding library of mutants. In silico screening was applied to select reactive enzyme-substrate complexes that satisfy knowledge-based criteria of amidase catalytic activity. Selected CALB variants with substitutions at subfamily-specific positions Gly39, Thr103, Trp104, and Leu278 were produced and showed significant improvement of experimentally measured amidase activity. Based on these results, we suggest that value of subfamily-specific positions should be further explored in order to develop a systematic tool to study structure-function relationship in enzymes and to use this information for rational enzyme engineering.

In silico identification of potent pancreatic triacylglycerol lipase inhibitors from traditional Chinese medicine

Pancreatic triacylglycerol lipase (PNLIP) are primary lipases that are critical for triacylglyceride digestion in human. Since reduced metabolism of triacylglyceride might be a plausible concept for weight loss, we screened for potential PNLIP inhibitors from traditional Chinese medicine (TCM) with the aim to identify weight loss candidate compounds. TCM candidates Aurantiamide, Cnidiadin, and 2-hexadecenoic acid exhibited higher Dock Scores than the commercial drug Orlistat, and were also predicted to have inhibitory characteristics against PNLIP using constructed MLR (R² = 0.8664) and SVM (R² = 0.9030) models. Molecular dynamics indicated that the TCM-PNLIP complexes formed were stable. We identified that the PNLIP binding site has several residues that can serve as anchors, and a hydrophobic corridor that provides additional stability to the complex. Aurantiamide, Cnidiadin, and 2-hexadecenoic acid all have features that correspond to these binding site features, indicating their potential as candidates for PNLIP inhibitors. The information presented in this study may provide helpful insights to designing novel weight-control drugs.

In vitro inhibitory effect on pancreatic lipase activity of subfractions from ethanol extracts of fermented Oats (Avena sativa L.) and synergistic effect of three phenolic acids

The purpose of the present work is to study the pancreatic lipase inhibitory effects of different subfractions (n-hexane, ethyl acetate (EA), n-butanol, and water) from ethanol extracts of nonfermented and fungi-fermented oats and to delineate the interactions of three primary phenolic acids in the EA subfractions. The EA subfraction showed the highest inhibitory effect on pancreatic lipase activity at 1.5 mg/mL compared to the other subfractions, regardless of whether the oats were fermented. Meanwhile, both of the EA subfractions of two fungi-fermented oats demonstrated more effective inhibitory activity than that of nonfermented oats. A positive correlation between the total phenolics content and inhibitory activity was found. The inhibitory ability of the EA subfraction from nonfermented or fermented oats also displayed a dose-dependent effect. The standards of caffeic, ferulic, and p-coumaric acids, mainly included in EA subfractions of fermented oats, also displayed a dose-dependent inhibitory effect. A synergistic effect of each binary combination of p-coumaric, ferulic, and caffeic acids was observed, especially at 150.0 μg/mL. Those results indicate that fungi-fermented oats have a more effective inhibitory ability on pancreatic lipase and polyphenols may be the most effective component and could be potentially used for dietary therapy of obesity.

Screening of crude plant extracts with anti-obesity activity

Obesity is a global health problem. It is also known to be a risk factor for the development of metabolic disorders, type 2 diabetes, systemic hypertension, cardiovascular disease, dyslipidemia, and atherosclerosis. In this study, we screened crude extracts from 400 plants to test their anti-obesity activity using porcine pancreatic lipase assay (PPL; triacylglycerol lipase, EC 3.1.1.3) in vitro activity. Among the 400 plants species examined, 44 extracts from plants, showed high anti-lipase activity using 2,4-dinitrophenylbutyrate as a substrate in porcine pancreatic lipase assay. Furthermore, 44 plant extracts were investigated for their inhibition of lipid accumulation in 3T3-L1 cells. Among these 44 extracts examined, crude extracts from 4 natural plant species were active. Salicis Radicis Cortex had the highest fat inhibitory activity, whereas Rubi Fructus, Corni Fructus, and Geranium nepalense exhibited fat inhibitory capacity higher than 30% at 100 μg/mL in 3T3-L1 adipocytes, suggesting anti-obesity activity. These results suggest that four potent plant extracts might be of therapeutic interest with respect to the treatment of obesity.

Screening for anti-lipase properties of 37 traditional Chinese medicinal herbs

BACKGROUND

To find new, crude anti-obesity drugs from natural sources through the inhibition of adsorption of dietary lipids, in vitro porcine pancreatic lipase (PPL; triacylglycerol lipase, EC 3.1.1.3) inhibitory tests were carried out on selected plants with weight-reducing or related potential, used in Chinese traditional medicine.

METHODS

The methanolic extracts of 37 traditional Chinese herbal medicines of different families were assayed for their in vitro activity against PPL by using spectrophotometry with 2,4-dinitrophenyl butyrate as a synthetic substrate. Coexistent phytochemicals, or those present in high levels, in the 3 most promising Chinese herbs were tested for their anti-lipase activity.

RESULTS

Extracts from 2 herbs, Prunella vulgaris L. (Labiatae) and Rheum palmatum L. (Polygonaceae), at a concentration of 200 mg/mL, significantly inhibited PPL-by 74.7% and 53.8%, respectively. Quercetin exhibited better activity (27.4%) than all the other phytochemicals at a final concentration of 25 mg/mL in the assay system, followed by luteolin, with an activity of 17.3%.

CONCLUSION

The results support the view that herbs represent a rich source of anti-lipase compounds. The screening of the methanolic extracts of 37 Chinese medicinal plants in vitro led to the identification of several extracts with potential activity against PPL, in particular, P. vulgaris and R. palmatum. We also found that several monomeric chemicals in these herbs exhibited good or moderate activity against PPL. To the best of our knowledge, these traditional Chinese herbal medicines or phytochemicals have not been previously screened for their lipase inhibitory activity.

The role of lipid and carbohydrate digestive enzyme inhibitors in the management of obesity: a review of current and emerging therapeutic agents

Obesity is a global epidemic associated with significant morbidity and mortality in adults and ill health in children. A proven successful approach in weight management has been the disruption of nutrient digestion, with orlistat having been used to treat obesity for the last 10 years. Although orlistat-induced weight loss remains modest, it produces meaningful reductions in risk factors for obesity-related conditions such as diabetes and cardiovascular disease. Moreover, this lipase inhibitor is free of the serious side effects that have dogged appetite-suppressing drugs. This success had driven investigation into new generation nutraceuticals, supplements and pharmaceutical agents that inhibit the breakdown of complex carbohydrates and fats within the gut. This review focuses on agents purported to inhibit intestinal enzymes responsible for macronutrient digestion. Except for some synthetic products, the majority of agents reviewed are either botanical extracts or bacterial products. Currently, carbohydrate digestion inhibitors are under development to improve glycemic control and these may also induce some weight loss. However, colonic fermentation induced side effects, such as excess gas production, remain an issue for these compounds. The α-glucosidase inhibitor acarbose, and the α-amylase inhibitor phaseolamine, have been used in humans with some promising results relating to weight loss. Nonetheless, few of these agents have made it into clinical studies and without any clinical proof of concept or proven efficacy it is unlikely any will enter the market soon.

Identification and characterization of 4-aryl-3,4-dihydropyrimidin-2(1H)-ones as inhibitors of the fatty acid transporter FATP4

Several potent, cell permeable 4-aryl-dihydropyrimidinones have been identified as inhibitors of FATP4. Lipophilic ester substituents at the 5-position and substitution at the para-position (optimal groups being -NO(2) and CF(3)) of the 4-aryl group led to active compounds. In two cases racemates were resolved and the S enantiomers shown to have higher potencies.

Hypolipemic effect of Cyclocarya paliurus (Batal) Iljinskaja in lipid-loaded mice

We investigated the inhibitory effect of Cyclocarya paliurus (Batal.) Iljinskaja (C. paliurus) extract on postprandial hyperlipemia in mice. A single oral administration of C. paliurus extract (250 mg/kg) suppressed an increase in plasma triacylgycerol (TG) levels when fed with 5 ml/kg of lard and olive oil. The inhibition rates were 28.6% and 24.1%, respectively, but free fatty acid (FFA) levels in plasma were not significantly affected as compared with control group mice. In addition, C. paliurus extract showed inhibitory activity toward pancreatic lipase, a key enzyme of dietary TG absorption, with an IC(50) of 9.1 microg/ml in vitro. Our results suggested that the hypolipemic action of C. paliurus extract was probably interrelated with suppression of the activity of digestive lipase, and as a result, the blood lipid level was reduced.

The role of leptin in fertility

The relationship between metabolism and reproduction remains a mystery in female endocrinology. Such substances as insulin, amino acids and IGFBP-I have been proposed as signals of body mass fat on the genital axis. Today this role is claimed by leptin, a protein hormone decoded from the obesity gene and is secreted exclusively from adipose tissue. This hormone acts on the central nervous system (CNS) to result in the suppression of food intake and increase in energy consumption. What is more, it also influences the capacity for reproduction. This paper reports findings with regard to the factors influencing the secretion of leptin and identification of the leptin's hormonal receptors. Particular emphasis was placed on the relationship between secretion of leptin and disturbances in menstruation, the anticipated role of this hormone in the pathogenesis of the polycystic ovarian syndrome (PCOS) and its effects on the reproductive capacity.

Synthesis of lipophilic aldehydes and study of their inhibition effect on human digestive lipases

[reaction: see text] Novel inhibitors of human digestive lipases, aldehyde dialkyl and alkyl-acyl glycerol analogues, were developed. The inhibitors were prepared starting from 3-(benzyloxy)-1,2-propanediol. The inhibition of human pancreatic and gastric lipases by the aldehyde derivatives was studied using the monolayer technique. (1R)-1-[(Dodecyloxy)methyl]-4-oxobutyl decanoate caused a 50% decrease in HPL and HGL activities at 0.100 and 0.053 molar fractions, respectively.

Bis-2-oxo amide triacylglycerol analogues: a novel class of potent human gastric lipase inhibitors

A novel class of potent human gastric lipase inhibitors, bis-2-oxo amide triacylglycerol analogues, was developed. These analogues of the natural substrate of lipases were prepared starting from 1,3-diaminopropan-2-ol. They were designed to contain the 2-oxo amide functionality in place of the scissile ester bond at the sn-1 and sn-3 position, while the ester bond at the sn-2 position was either maintained or replaced by an ether bond. The derivatives synthesized were tested for their ability to form stable monomolecular films at the air/water interface by recording their surface pressure/molecular area compression isotherms. The inhibition of human pancreatic and gastric lipases by the bis-2-oxo amides was studied using the monolayer technique with mixed films of 1,2-dicaprin containing variable proportions of each inhibitor. The nature of the functional group (ester or ether), as well as the chain length, at the sn-2 position influenced the potency of the inhibition. Among the compounds tested, 2-[(2-oxohexadecanoyl)amino]-1-[[(2-oxohexadecanoyl)-amino]methyl]ethyl decanoate was the most potent inhibitor, causing a 50% decrease in HPL and HGL activities at 0.076 and 0.020 surface molar fractions, respectively.

Nontraditional microbial bioactive metabolites

Microorganisms produce low-molar-mass secondary metabolites exhibiting different biological activities, which are used. e.g., in medicine as antimicrobial and antifungal agents, alkaloids and toxins. Some of these substances have highly diverse biological activities and unusual structures. They are produced by streptomycetes, fungi, and bacilli, but interesting products have also been obtained from microorganisms growing in extreme conditions. Several thousands of microbial products have so far been discovered and many other, which can be potentially useful and/or prospective for human use, can still be in the offing.

Synthesis of 2-Oxo amide triacylglycerol analogues and study of their inhibition effect on pancreatic and gastric lipases

A general method for the synthesis of chiral 2-oxo amide triacylglycerol analogues, from (R)- or (S)-3-aminopropane-1,2-diol, was developed. These novel inhibitors of digestive lipases are analogues of the triacylglycerol molecule, a natural substrate of lipases, and they were designed to contain the 2-oxo amide functionality in place of the scissile ester bond at the sn-1 or sn-3 position and nonhydrolysable ether bonds instead of ester bonds at the other two remaining positions. The 2-oxo amide derivatives synthesised were tested for their ability to form stable monomolecular films at the air/water interface by recording their surface pressure/molecular area compression isotherms. The inhibition of porcine pancreatic and human gastric lipases by the 2-oxo amides was studied by means of the monolayer technique with mixed films of 1,2-dicaprin and with variable proportions of each inhibitor. The alpha50 values of these triacylglycerol analogues for PPL and HGL varied between 4.4 to 7.0% and 5.6 to 15.9%, respectively. The chirality at the sn-2 position of 2-oxo amide triacylglycerol analogues affected the alpha50 value for HGL, but not for PPL.

Synthesis and study of a lipophilic alpha-keto amide inhibitor of pancreatic lipase

[reaction: see text] A lipophilic alpha-keto amide, inhibitor of pancreatic lipase, was synthesized using a lipidic 2-amino alcohol as backbone. The chiral key intermediate 2-(tert-butyloxycarbonylamino)-D-undecen-5-ol was synthesized starting from D-glutamic acid. The inhibitor formed a stable monomolecular film at the air/water interface as shown by a force/area curve. Inhibition studies using the monomolecular film technique with mixed films of 1,2-dicaprin containing variable proportions of the inhibitor showed a 50% decrease in lipase activity at a 0.14 molar fraction.

Identification of the major intestinal fatty acid transport protein

While intestinal transport systems for metabolites such as carbohydrates have been well characterized, the molecular mechanisms of fatty acid (FA) transport across the apical plasmalemma of enterocytes have remained largely unclear. Here, we show that FATP4, a member of a large family of FA transport proteins (FATPs), is expressed at high levels on the apical side of mature enterocytes in the small intestine. Further, overexpression of FATP4 in 293 cells facilitates uptake of long chain FAs with the same specificity as enterocytes, while reduction of FATP4 expression in primary enterocytes by antisense oligonucleotides inhibits FA uptake by 50%. This suggests that FATP4 is the principal fatty acid transporter in enterocytes and may constitute a novel target for antiobesity therapy.