Pancreatic lipase inhibition activity of trilactone terpenes of Ginkgo biloba

Ginkgo biloba attenuated detrimental inflammatory and oxidative events due to Trypanosoma brucei rhodesiense in mice treated with melarsoprol

BACKGROUND

The severe late stage Human African Trypanosomiasis (HAT) caused by Trypanosoma brucei rhodesiense (T.b.r) is characterized by damage to the blood brain barrier, severe brain inflammation, oxidative stress and organ damage. Melarsoprol (MelB) is currently the only treatment available for this disease. MelB use is limited by its lethal neurotoxicity due to post-treatment reactive encephalopathy. This study sought to assess the potential of Ginkgo biloba (GB), a potent anti-inflammatory and antioxidant, to protect the integrity of the blood brain barrier and ameliorate detrimental inflammatory and oxidative events due to T.b.r in mice treated with MelB.

METHODOLOGY

Group one constituted the control; group two was infected with T.b.r; group three was infected with T.b.r and treated with 2.2 mg/kg melarsoprol for 10 days; group four was infected with T.b.r and administered with GB 80 mg/kg for 30 days; group five was given GB 80mg/kg for two weeks before infection with T.b.r, and continued thereafter and group six was infected with T.b.r, administered with GB and treated with MelB.

RESULTS

Co-administration of MelB and GB improved the survival rate of infected mice. When administered separately, MelB and GB protected the integrity of the blood brain barrier and improved neurological function in infected mice. Furthermore, the administration of MelB and GB prevented T.b.r-induced microcytic hypochromic anaemia and thrombocytopenia, as well as T.b.r-driven downregulation of total WBCs. Glutathione analysis showed that co-administration of MelB and GB prevented T.b.r-induced oxidative stress in the brain, spleen, heart and lungs. Notably, GB averted peroxidation and oxidant damage by ameliorating T.b.r and MelB-driven elevation of malondialdehyde (MDA) in the brain, kidney and liver. In fact, the co-administered group for the liver, registered the lowest MDA levels for infected mice. T.b.r-driven elevation of serum TNF-α, IFN-γ, uric acid and urea was abrogated by MelB and GB. Co-administration of MelB and GB was most effective in stabilizing TNFα levels. GB attenuated T.b.r and MelB-driven up-regulation of nitrite.

CONCLUSION

Utilization of GB as an adjuvant therapy may ameliorate detrimental effects caused by T.b.r infection and MelB toxicity during late stage HAT.

Stevia Polyphenols, Their Antimicrobial and Anti-Inflammatory Properties, and Inhibitory Effect on Digestive Enzymes

Polyphenols from stevia leaves (PPSs) are abundant byproducts from steviol glycoside production, which have been often studied as raw extracts from stevia extracts for their bioactivities. Herein, the PPSs rich in isochlorogenic acids were studied for their antimicrobial and anti-inflammatory properties, as well as their inhibitory effects on digestive enzymes. The PPSs presented stronger antibacterial activity against E. coli, S. aureus, P. aeruginosa, and B. subtilis than their antifungal activity against M. furfur and A. niger. Meanwhile, the PPSs inhibited four cancer cells by more than 60% based on their viability, in a dose-dependent manner. The PPSs presented similar IC50 values on the inhibition of digestive enzyme activities compared to epigallocatechin gallate (EGCG), but had weaker anti-inflammatory activity. Therefore, PPSs could be a potential natural alternative to antimicrobial agents. This is the first report on the bioactivity of polyphenols from stevia rebaudiana (Bertoni) leaves excluding flavonoids, and will be of benefit for understanding the role of PPSs and their application.

The colloid and interface strategies to inhibit lipid digestion for designing low-calorie food

Although fat is one of the indispensable components of food flavor, excessive fat consumption could cause obesity, metabolism syndromes and an imbalance in the intestinal flora. In the pursuit of a healthy diet, designing fat reducing foods by inhibiting lipid digestion and calorie intake is a promising strategy. Altering the gastric emptying rates of lipids as well as acting on the lipase by suppressing the enzymatic activity or limiting lipase diffusion via interfacial modulation can effectively decrease lipolysis rates. In this review, we provide a comprehensive overview of colloid-based strategies that can be employed to retard lipid hydrolysis, including pancreatic lipase inhibitors, emulsion-based interfacial modulation and fat substitutes. Plants-/microorganisms-derived lipase inhibitors bind to catalytic active sites and change the enzymatic conformation to inhibit lipase activity. Introducing oil-in-water Pickering emulsions into the food can effectively delay lipolysis via steric hindrance of interfacial particulates. Regulating stability and physical states of emulsions can also affect the rate of hydrolysis by altering the active hydrolysis surface. 3D network structure assembled by fat substitutes with high viscosity can not only slow down the peristole and obstruct the diffusion of lipase to the oil droplets but also impede the transportation of lipolysis products to epithelial cells for adsorption. Their applications in low-calorie bakery, dairy and meat products were also discussed, emphasizing fat intake reduction, structure and flavor retention and potential health benefits. However, further application of these strategies in large-scale food production still requires more optimization on cost and lipid reducing effects. This review provides a comprehensive review on colloidal approaches, design, principles and applications of fat reducing strategies to meet the growing demand for healthier diet and offer practical insights for the low-calorie food industry.

Inhibitory Effects of Saponin-Rich Extracts from Pouteria cambodiana against Digestive Enzymes α-Glucosidase and Pancreatic Lipase

Pouteria cambodiana is a perennial plant that has a wide distribution in tropical regions. It is commonly referred to as 'Nom-nang' in the northern region of Thailand. The bark of this plant has been used for the purpose of promoting lactation among breastfeeding mothers. Moreover, P. cambodiana bark has a high nutraceutical potential due to the presence of saponins, which are secondary metabolites. The purpose of this study was to determine the optimal conditions for ultrasound-assisted extraction (UAE) of saponins from the bark of P. cambodiana and to assess the in vitro inhibitory activities of saponin-rich extracts. The most effective extraction conditions involved a temperature of 50 °C and a 50% concentration level of ethanol as the solvent, which allowed the extraction of saponin at a concentration of 36.04 mg/g. Saponin-rich extracts and their hydrolysates from P. cambodiana bark were evaluated for their ability to inhibit α-glucosidase and pancreatic lipase. The IC50 values for saponin- and sapogenin-rich extracts inhibiting α-glucosidase were 0.10 and 2.98 mg/mL, respectively. Non-hydrolysed extracts also had a stronger inhibitory effect than acarbose. In the case of pancreatic lipase, only the hydrolysed extracts exhibited inhibitory effects on pancreatic lipase (IC50 of 7.60 mg/mL). Thus, P. cambodiana bark may be an applicable natural resource for preparing ingredients for functional products with inhibitory activity against α-glucosidase and pancreatic lipase. The phenolic contents, saponin contents, and antioxidant activities of the dried extract stored at a low temperature of 25 °C for 2 months showed the best stability, with more than 90% retention.

Pancreatic lipase digestion: The forgotten barrier in oral administration of lipid-based delivery systems?

This review highlights the importance of controlling the digestion process of orally administered lipid-based delivery systems (LBDS) and their performance. Oral LBDS are prone to digestion via pancreatic lipase in the small intestine. Rapid or uncontrolled digestion may cause the loss of delivery system integrity, its structural changes, reduced solubilization capacity and physical stability issues. All these events can lead to uncontrolled drug release from the digested LBDS into the gastrointestinal environment, exposing the incorporated drug to precipitation or degradation by luminal proteases. To prevent this, the digestion rate of orally administered LBDS can be estimated by appropriate choice of the formulation type, excipient combinations and their ratios. In addition, in vitro digestion models like pH-stat are useful tools to evaluate the formulation digestion rate. Controlling digestion can be achieved by conventional lipase inhibitors like orlistat, sterically hindering of lipase adsorption on the delivery system surface with polyethylene glycol (PEG) chains, lipase desorption or saturation of the interface with surfactants as well as formulating LBDS with ester-free excipients. Recent in vivo studies demonstrated that digestion inhibition lead to altered pharmacokinetic profiles, where Cmax and Tmax were reduced in spite of same AUC compared to control or even improved oral bioavailability.

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.

The use of cellulose, chitosan and hyaluronic acid in transdermal therapeutic management of obesity: A review

Obesity is a clinical condition with rising popularity and detrimental impacts on human health. According to the World Health Organization, obesity is the sixth most common cause of death worldwide. It is challenging to combat obesity because medications that are successful in the clinical investigation have harmful side effects when administered orally. The conventional approaches for treating obesity primarily entail synthetic compounds and surgical techniques but possess severe adverse effects and recurrences. As a result, a safe and effective strategy to combat obesity must be initiated. Recent studies have shown that biological macromolecules of the carbohydrate class, such as cellulose, hyaluronic acid, and chitosan, can enhance the release and efficacy of medications for obesity but due to their short biological half-lives and poor oral bioavailability, their distribution rate is affected. This helps to comprehend the need for an effective therapeutic approach via a transdermal drug delivery system. This review focuses on the transdermal administration, utilizing cellulose, chitosan, and hyaluronic acid via microneedles, as it offers a promising solution to overcome existing therapy limitations in managing obesity and it also highlights how microneedles can effectively deliver therapeutic substances through the skin's outer layer, bypassing pain receptors and specifically targeting adipose tissue.

Screening and identification of lipase inhibitors extracted from Dioscorea nipponica Makino by UV-vis and HPLC coupled to UPLC-Q-TOF-MS/MS

Dioscoreae nipponica Makino (D. nipponica) as the rhizome of dioscoreaceae rich in steroidal saponins, has been reported to have the hypolipidemic effects etc. However, it is still unclear which exact active components are primary responsible for the beneficial effects. This study was conducted to fish out the lipase inhibitors from D. nipponica, and evaluate the inhibitory activity on porcine pancreatic lipase (PPL) through in vitro kinetic assay using p-nitrophenyl palmitate as substrate. Accordingly, the ethanolic extract was subjected to D101 macroporous resin purification for spectrophotometric screening, high performance liquid chromatography (HPLC) separation and structural characterization by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. Through orlistat validation, the PPL inhibitory activity and IC₅₀ value of the extract were respectively 68.34 ± 1.47 % and 107.05 μg/mL under the optimized inhibition conditions. From 6 steroidal saponins identified, the inhibitory components named the protodioscin, protogracillin, dioscin and gracillin were fished out by grouping separation and HPLC analysis. Furthermore, dioscin and gracillin with the parent structure of diogenin were confirmed as the major inhibitors by virtue of stability tests based on transformation of protodioscin and protogracillin. Finally, the inhibitory mechanism of the major inhibitors toward PPL was further clarified by kinetic analysis and molecular docking analysis. The proposed method not only revealed the PPL inhibitory components in D. nipponica, but also provided an effective approach to hierarchical screening of PPL inhibitors from natural plants.

In Vitro and In Silico Study of the α-Glucosidase and Lipase Inhibitory Activities of Chemical Constituents from Piper cumanense (Piperaceae) and Synthetic Analogs

Digestive enzymes are currently considered important therapeutic targets for the treatment of obesity and some associated metabolic diseases, such as type 2 diabetes. Piper cumanense is a species characterized by the presence of bioactive constituents, particularly prenylated benzoic acid derivatives. In this study, the inhibitory potential of chemical constituents from P. cumanense and some synthesized compounds was determined on digestive enzymes (pancreatic lipase (PL) and α-glucosidase (AG)). The methodology included isolating and identifying secondary metabolites from P. cumanense, synthesizing some analogs, and a molecular docking study. The chemical study allowed the isolation of four prenylated benzoic acid derivatives (1–4). Four analogs (5–8) were synthesized. Seven compounds were found to significantly inhibit the catalytic activity of PL with IC₅₀ values between 28.32 and 55.8 µM. On the other hand, only two compounds (6 and 7) were active as inhibitors of AG with IC₅₀ values lower than 155 µM, standing out as the potential multitarget of these chromane compounds. Enzyme kinetics and molecular docking studies showed that the bioactive compounds mainly interact with amino acids other than those of the catalytic site in both PL and AG. This work constitutes the first report on the antidiabetic and antiobesity potential of substances derived from P. cumanense.

Multitarget Action of Xanthones from Garcinia mangostana against α-Amylase, α-Glucosidase and Pancreatic Lipase

Digestive enzymes such α-amylase (AA), α-glucosidase (AG) and pancreatic lipase (PL), play an important role in the metabolism of carbohydrates and lipids, being attractive therapeutic targets for the treatment of type 2 diabetes and obesity. Garcinia mangostana is an interesting species because there have been identified xanthones with the potential to inhibit these enzymes. In this study, the multitarget inhibitory potential of xanthones from G. mangostana against AA, AG and PL was assessed. The methodology included the isolation and identification of bioactive xanthones, the synthesis of some derivatives and a molecular docking study. The chemical study allowed the isolation of five xanthones (1–5). Six derivatives (6–11) were synthesized from the major compound, highlighting the proposal of a new solvent-free methodology with microwave irradiation for obtaining aromatic compounds with tetrahydropyran cycle. Compounds with multitarget activity correspond to 2, 4, 5, 6 and 9, highlighting 6 with IC₅₀ values of 33.3 µM on AA, 69.2 µM on AG and 164.4 µM on PL. Enzymatic kinetics and molecular docking studies showed that the bioactive xanthones are mainly competitive inhibitors on AA, mixed inhibitors on AG and non-competitive inhibitors on PL. The molecular coupling study established that the presence of methoxy, hydroxyl and carbonyl groups are important in the activity and interaction of polyfunctional xanthones, highlighting their importance depending on the mode of inhibition.

Computational analysis of marine algal compounds for obesity management against pancreatic lipase

Obesity is considered a global crisis because of its increased risk factors triggered by lifestyle changes. The prevalence of this condition is increasing at an alarming rate, giving rise to development of novel drugs. Pancreatic lipase possesses higher efficacy in inhibiting this condition among the other drug targets. In this study, virtual screening of 126 plant-derived anti-obesity compounds and 1110 marine algal compounds from seaweed metabolite database were screened and targeted against pancreatic lipase and ranked based on their binding affinity values. A total of 530 compounds that possessed best docked scores of less than -6 kcal/mol were checked for Lipinski's properties through Swiss ADME. Furthermore, these compounds were subjected to toxicity prediction using PROTOX II server. As much as 38 compounds were found to be non-toxic and were subjected to molecular docking analysis. Based on the binding energy, the following compounds RG012 (-10.15 kcal/mol), LIG42 (-9.7 kcal/mol), BC010 (-8.47 kcal/mol), RL073 (-8.2 kcal/mol), and LIG46 (-8.03 kcal/mol) were selected exhibiting higher binding affinity when compared to the standard drug (Orlistat) and hence these compounds were subjected to molecular dynamics simulation using GROMACS. BC010 complex revealed a stable interaction within the binding pocket and the binding free energy is -158.208 kJ/mol which is higher when compared to other complexes in 100 ns simulation. BC010 ((7S,11S,12S,14R)-4',14-dimethoxyamentol) from brown algae Cystophora fibrosa could be considered as a potential drug candidate to suppress obesity by inhibiting pancreatic lipase.Communicated by Ramaswamy H. Sarma.

Resin glycosides in aerial parts of Ipomoea batatas are potent lipase inhibitors: potential upcycling of sweet potato by-products to combat obesity

Sweet potato (Ipomoea batatas) is a staple food crop that is cultivated globally. While the tubers are widely utilised in the food industry, 95-98% of sweet potato leaves (SPL) are disposed during harvesting. Hence, there is great potential to convert SPL into high-value food products through various processing techniques. In this regard, different varieties of Ipomoea batatas (Blackie, Blackheart, and Margarita) that were grown in Singapore were tested for their pancreatic lipase (PL) inhibitory activity using a high-throughput screening assay. Among them, the Margarita variety showed the highest PL inhibitory activity with an Orlistat Equivalent (OE) value of 3.83 ± 0.36 × 10^-4. The kinetic study of the Margarita extract revealed a non-competitive inhibition mechanism. Overall, a series of resin glycosides (RG), responsible for the PL inhibitory activity, was characterised in Margarita Ipomoea batatas. To evaluate the effectiveness of RG under gastrointestinal conditions with high-fat food, in vitro digestion with salad dressing was performed. The in vitro digestion model showed that the consumption of RG with salad dressing was effective in delaying enzymatic fat digestion in a dose-dependent manner. The findings strongly suggested that the aerial parts of Ipomoea batatas have great potential to be upcycled into functional food to combat obesity.

Biogenic Phytochemicals Modulating Obesity: From Molecular Mechanism to Preventive and Therapeutic Approaches

The incidence of obesity and over bodyweight is emerging as a major health concern. Obesity is a complex metabolic disease with multiple pathophysiological clinical conditions as comorbidities are associated with obesity such as diabetes, hypertension, cardiovascular disorders, sleep apnea, osteoarthritis, some cancers, and inflammation-based clinical conditions. In obese individuals, adipocyte cells increased the expression of leptin, angiotensin, adipocytokines, plasminogen activators, and C-reactive protein. Currently, options for treatment and lifestyle behaviors interventions are limited, and keeping a healthy lifestyle is challenging. Various types of phytochemicals have been investigated for antiobesity potential. Here, we discuss pathophysiology and signaling pathways in obesity, epigenetic regulations, regulatory mechanism, functional ingredients in natural antiobesity products, and therapeutic application of phytochemicals in obesity.

Sterehirsutynes A - C: three new acetylenic aromatic metabolites from Stereum hirsutum

Three new acetylenic aromatic compounds, sterehirsutynes A-C (1-3), along with three known congeners, frustulosinol (4), vibrayne (5), and sterehirsutinol (6), were isolated from the culture broth of Stereum hirsutum. Their structures were determined by detailed analyses of NMR and high-resolution mass. Chiral column analysis showed that compounds 2 and 3 were racemic mixtures. These new compounds were evaluated for porcine pancreatic lipase (PPL) inhibitory activities, and compounds 1 and (±) 3 showed moderate inhibitory activity against PPL, with IC₅₀ values of 23.2 ± 1.04 and 21.8 ± 2.15 μM, respectively.

Antidiabetic, antioxidant, and anti-obesity effects of phenylthio-ethyl benzoate derivatives, and molecular docking study regarding α-amylase enzyme

In addition to their wide therapeutic application, benzoates and benzoic acid derivatives are the most commonly utilized food preservatives. The purpose of this study was to estimate the antioxidant, anti-diabetic, and anti-obesity activities of four 2-(phenylthio)-ethyl benzoate derivatives utilizing standard biomedical assays. The results revealed that the 2a compound has potent antidiabetic activity through the inhibition of α-amylase and α-glycosidase with IC₅₀ doses of 3.57 ± 1.08 and 10.09 ± 0.70 µg/ml, respectively, compared with the positive control acarbose (IC₅₀ = 6.47 and 44.79 µg/ml), respectively. In addition, by utilizing the β-carotene linoleic acid and DPPH methods, the 2a compound showed the highest antioxidant activity compared with positive controls. Moreover, the 2a compound showed potential anti-lipase activity with an IC₅₀ dose of 107.95 ± 1.88 µg/ml compared to orlistat (IC₅₀ = 25.01 ± 0.78 µg/ml). A molecular docking study was used to understand the interactions between four derivatives of (2-(phenylthio)-ethyl benzoate with α-amylase binding pocket. The present study concludes that the 2a compound could be exploited for further antidiabetic, antioxidant, and anti-obesity preclinical and clinical tests and design suitable pharmaceutical forms to treat these global health problems.

Structure, synthesis, biosynthesis, and activity of the characteristic compounds from Ginkgo biloba L

Covering: 1928-2021Ginkgo biloba L. is one of the most distinctive plants to have emerged on earth and has no close living relatives. Owing to its phylogenetic divergence from other plants, G. biloba contains many compounds with unique structures that have served to broaden the chemical diversity of herbal medicine. Examples of such compounds include terpene trilactones (ginkgolides), acylated flavonol glycosides (ginkgoghrelins), biflavones (ginkgetin), ginkgotides and ginkgolic acids. The extract of G. biloba leaf is used to prevent and/or treat cardiovascular diseases, while many ginkgo-derived compounds are currently at various stages of preclinical and clinical trials worldwide. The global annual sales of G. biloba products are estimated to total US$10 billion. However, the content and purity of the active compounds isolated by traditional methods are usually low and subject to varying environmental factors, making it difficult to meet the huge demand of the international market. This highlights the need to develop new strategies for the preparation of these characteristic compounds from G. biloba. In this review, we provide a detailed description of the structures and bioactivities of these compounds and summarize the recent research on the development of strategies for the synthesis, biosynthesis, and biotechnological production of the characteristic terpenoids, flavonoids, and alkylphenols/alkylphenolic acids of G. biloba. Our aim is to provide an important point of reference for all scientists who research ginkgo-related compounds for medicinal or other purposes.

Molecular docking, chemo-informatic properties, alpha-amylase, and lipase inhibition studies of benzodioxol derivatives

Currently, available therapies for diabetes could not achieve normal sugar values in a high percentage of treated patients. In this research project, a series of 17 benzodioxole derivatives were evaluated as antidiabetic agents; that belong to three different groups were evaluated against lipase and alpha-amylase (α-amylase) enzymes. The results showed that 14 compounds have potent inhibitory activities against α-amylase with IC₅₀ values below 10 µg/ml. Among these compounds, 4f was the most potent compound with an IC₅₀ value of 1.11 µg/ml compared to the anti-glycemic agent acarbose (IC₅₀ 6.47 µg/ml). On the contrary, these compounds showed weak or negligible activities against lipase enzyme. However, compound 6a showed the best inhibitory anti-lipase activity with IC₅₀ 44.1 µg/ml. Moreover, all the synthesized compounds were undergone Molinspiration calculation, and the result showed that all compounds obeyed Lipinski's rule of five. Molecular docking studies were performed to illustrate the binding interactions between the benzodioxole derivatives and α-amylase enzyme pocket. Related to the obtained results it was clear that the carboxylic acid, benzodioxole ring, halogen or methoxy substituted aryl are important for the anti-amylase activities. The potent inhibitory results of some of the synthesized compounds suggest that these molecules should go further in vivo evaluation. It also suggests the benzodioxole derivatives as lead compounds for developing new drug candidates.

New insights into the cholesterol esterase- and lipase-inhibiting potential of bioactive peptides from camel whey hydrolysates: Identification, characterization, and molecular interaction

Novel antihypercholesterolemic bioactive peptides (BAP) from peptic camel whey protein hydrolysates (CWPH) were generated at different time, temperature, and enzyme concentration (%). Hydrolysates showed higher pancreatic lipase- (PL; except 3 CWPH) and cholesterol esterase (CE)-inhibiting potential, as depicted by lower half-maximal inhibitory concentration values (IC₅₀ values) compared with nonhydrolyzed camel whey proteins (CWP). Peptide sequencing and in silico data depicted that most BAP from CWPH could bind active site of PL, whereas as only 3 peptides could bind the active site of CE. Based on higher number of reactive residues in the BAP and greater number of substrate binding sites, FCCLGPVPP was identified as a potential CE-inhibitory peptide, and PAGNFLPPVAAAPVM, MLPLMLPFTMGY, and LRFPL were identified as PL inhibitors. Molecular docking of selected peptides showed hydrophilic and hydrophobic interactions between peptides and target enzymes. Thus, peptides derived from CWPH warrant further investigation as potential candidates for adjunct therapy for hypercholesterolemia.

Inhibitory kinetics and mechanism of pentacyclic triterpenoid from endophytic Colletotrichum gigasporum against pancreatic lipase

The burden of obesity is increasing all over the world. Except for Orlistat, no effective anti-obesity drug is currently available. Therefore, a search for the new anti-obesity compound is need of time. This study demonstrates macromolecular interaction and inhibitory effect of pentacyclic triterpenoids (PTT) on pancreatic lipase (PL). In the present study PTTs from endophytic Colletotrichum gigasporum were found to show significant inhibitory activity against PL with IC₅₀ of 16.62 ± 1.43 μg/mL. The PTT isolated through bioassay-guided isolation showed a dose-dependent (R² = 0.915) inhibition against porcine PL and the results were comparable with the standard (Orlistat). Based on inhibition kinetic data, the gradual increase in K_{m (app)} with increasing PTT concentration indicated that the mode of interaction of PTT with PL was a competitive type, and it directly competed with the substrate (pNPB) for the active site of PL. In vivo studies in Wistar rats at the oral dose (100 mg/kg body weight) of PTT significantly decreased (p < 0.05) incremental plasma triglyceride levels as compared to group B and TG absorption was down-regulated up to 49.18% vis a vis group D animals. The isolated PTT was identified as lupeol based on chromatographic and spectral data. The endophytic isolate was identified as Colletotrichum gigasporum based on morphology and ITS gene sequencing. The present study indicated that PTT had the potential to be used as a natural PL inhibitor in the treatment of obesity and the isolated endophyte can be a valuable bioresource for it.

Kinetic Behaviour of Pancreatic Lipase Inhibition by Ultrasonicated A. malaccensis and A. subintegra Leaves of Different Particle Sizes

Gallic acid and quercetin equivalent were determined in the crude extract of matured leaves Aquilaria malaccensis and Aquilaria subintegra. The leaves of both Aquilaria species were dried at 60 °C for 24 hours, ground and sieved into particle size of 250, 300, 400, 500, and 1000 µm. Then, each particle size of leaves was soaked in distilled water with a ratio of 1:100 (w/v) for 24 hours and undergoes the pre-treatment method by using ultrasonicator (37 kHz), at the temperature of 60 °C for 30 minutes. The crude extracts were obtained after about 4 hours of hydrodistillation process. The highest concentration of gallic acid and quercetin equivalent was determined in the crude extract from the particle size of 250 µm. The kinetics of pancreatic lipase inhibition was further studied based using the Lineweaver-Burk plot, wherein the concentration of p-NPP as the substrate and pancreatic lipase were varied. Based on the formation of the lines in the plot, the crude leaves extract of both Aquilaria species exhibit the mixed-inhibition on pancreatic lipase, which indicates that in the reaction, the inhibitors were not only attached to the free pancreatic lipase, but also to the pancreatic lipase-(p-NPP) complex. The reaction mechanism was similar to non-competitive inhibition; however the value of dissociation constant, Ki, for both inhibition pathways was different. The inhibition shows an increment in Michaelis-Menten constant (Km) and a reduction in the maximum pancreatic lipase activity (Vm) compared to the reaction without Aquilaria spp. crude extracts (control). This proved that the inhibition occurred in this reaction. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).  

Chemical composition, antimicrobial, and lipase enzyme activity of essential oil and solvent extracts from Serapias orientalis subsp. orientalis

The volatile components of essential oil (EO), SPME, and SPME of solvent extracts ( n -hexane, methanol, and water) obtained from fresh Serapias orientalis subsp. orientalis ( Soo ) were analyzed by GC-FID/MS. EO of Soo gave 11 compounds in the percentage of 99.97%; capronaldehyde (37.01%), 2-( E )-hexenal (23.19%), and n -nonanal (19.05%) were found to be major constituents. SPME GC-FID/MS analyses of fresh plant and solvent extracts of Soo revealed 7, 12, 7, and 4 compounds within the range of 99.7% to 99.9%. Limonene (76.5%, 41.7%, and 61.3%) was the major compound in SPMEs of the n -hexane and methanol extracts. α -Methoxy- p -cresol (52.9%) was the main component in its water extract. The antimicrobial activity of EO and the solvent extracts of Soo were screened against 9microorganisms. EO showed the best activity against Mycobacterium smegmatis , with 79.5 µg/mL MIC value. The n -hexane, methanol, and water extracts were the most active against the Staphylococcus aureus within the range of 81.25-125.0 µg/mL (MIC). IC 50 values for the lipase enzyme inhibitory activity of EO and solvent extracts ( n -hexane, methanol, and water) were determined to be 59.87 µg/mL, 64.03 µg/mL, 101.91 µg/mL, and 121.24 µg/mL, respectively.

Mechanisms of action for the anti-obesogenic activities of phytochemicals

The prevalence of obesity is increasing rapidly globally and has recently reached pandemic proportions. It is a multifactorial disorder linked to a number of non-communicable diseases such as type-2 diabetes, cardiovascular disease, and cancer. Over-nutrition and a sedentary lifestyle are considered the most significant causes of obesity; a healthy lifestyle and behavioural interventions are the most powerful ways to achieve successful weight loss, but to maintain this in the long term can prove difficult for many individuals, without medical intervention. Various pharmacological anti-obesogenic drugs have been tested and marketed in the past and have been moderately successful in the management of obesity, but their adverse effects on human health often outweigh the benefits. Natural products from plants, either in the form of crude extracts or purified phytochemicals, have been shown to have anti-obesogenic properties and are generally considered as nontoxic and cost-effective compared to synthetic alternatives. These plant products combat obesity by targeting the various pathways and/or regulatory functions intricately linked to obesity. Their mechanisms of action include inhibition of pancreatic lipase activities, an increase in energy expenditure, appetite regulation, lipolytic effects, and inhibition of white adipose tissue development. In this review, we discuss the distinct anti-obesogenic properties of recently reported plant extracts and specific bioactive compounds, along with their molecular mechanisms of action. This review will provide a common platform for understanding the different causes of obesity and the possible approaches to using plant products in tackling this worldwide health issue.

Antioxidant and pancreatic lipase inhibitory effects of flavonoids from different citrus peel extracts: An in vitro study

Obesity and oxidative damage are two important risk factors associated closely with metabolic syndrome. Utilization of functional food ingredients is considered as a feasible way to tackle these challenges. In the present study, eight representative species of citrus peel extracts (CPEs) were evaluated and compared for their flavonoid profiles, antioxidant activities, and pancreatic lipase (PL) inhibitory capacities and mechanisms. Results indicated that hesperidin, naringin, neohesperidin, narirutin and eriocitrin were the five major flavonoids in CPEs, among which hesperidin was the main active PL inhibitor. Moreover, hesperidin could interact with PL by hydrogen bonds and van der Waals forces, and the interaction would not obviously change the secondary structure of PL. Overall, ponkan peel extract, having the strongest overall antioxidant activity, the highest content of hesperidin and total phenolic compounds among all tested CPEs, is a promising natural ingredient to scavenge free radicals and manage obesity.

Computational approaches for the discovery of natural pancreatic lipase inhibitors as antiobesity agents

Obesity is becoming one of the greatest threats to global health in the 21st century and therefore the development of novel antiobesity drugs is one of the top priorities of global drug research. An important treatment strategy includes the reduction of intestinal fat absorption through the inhibition of pancreatic lipase (PL). Natural products provide a vast pool of PL inhibitors with novel scaffolds that can possibly be developed into clinical products. Computational drug design methods have become increasingly invaluable in the drug discovery process. In recent years, the discovery of new antiobesity PL inhibitors has been facilitated by the application of computational methods. This review highlights some computer-aided drug design techniques utilized in the discovery of natural PL inhibitors.

Identification of Anti-Mycobacterium and Anti-Legionella Compounds With Potential Distinctive Structural Scaffolds From an HD-PBL Using Phenotypic Screens in Amoebae Host Models

Tubercular Mycobacteria and Legionella pneumophila are the causative agents of potentially fatal respiratory diseases due to their intrinsic pathogenesis but also due to the emergence of antibiotic resistance that limits treatment options. The aim of our study was to explore the antimicrobial activity of a small ligand-based chemical library of 1255 structurally diverse compounds. These compounds were screened in a combination of three assays, two monitoring the intracellular growth of the pathogenic bacteria, Mycobacterium marinum and L. pneumophila, and one assessing virulence of M. marinum. We set up these assays using two amoeba strains, the genetically tractable social amoeba Dictyostelium discoideum and the free-living amoeba Acanthamoeba castellanii. In summary, 64 (5.1%) compounds showed anti-infective/anti-virulence activity in at least one of the three assays. The intracellular assays hit rate varied between 1.7% (n = 22) for M. marinum and 2.8% (n = 35) for L. pneumophila with seven compounds in common for both pathogens. In parallel, 1.2% (n = 15) of the tested compounds were able to restore D. discoideum growth in the presence of M. marinum spiked in a lawn of food bacteria. We also validated the generality of the hits identified in the A. castellanii–M. marinum anti-infective screen using the D. discoideum–M. marinum host–pathogen model. The characterization of anti-infective and antibacterial hits in the latter infection model revealed compounds able to reduce intracellular growth more than 50% at 30 μM. Moreover, the chemical space and physico-chemical properties of the anti-M. marinum hits were compared to standard and candidate Mycobacterium tuberculosis (Mtb) drugs using ChemGPS-NP. A principle component analysis identified separate clusters for anti-M. marinum and anti-L. pneumophila hits unveiling the potentially new physico-chemical properties of these hits compared to standard and candidate M. tuberculosis drugs. Our studies underscore the relevance of using a combination of low-cost and low-complexity assays with full 3R compliance in concert with a rationalized focused library of compounds to identify new chemical scaffolds and to dissect some of their properties prior to taking further steps toward compound development.

Targeting obesity with plant-derived pancreatic lipase inhibitors: A comprehensive review

The prevalence of obesity is alarmingly increasing in the last few decades and leading to many serious public health concerns worldwide. The dysregulated lipid homeostasis due to various genetic, environmental and lifestyle factors is considered one of the critical putative pathways mediating obesity. Nonetheless, the scientific advancements unleashing the molecular dynamics of lipid metabolism have provided deeper insights on the emerging roles of lipid hydrolysing enzymes, including pancreatic lipase. It is hypothesized that inhibiting pancreatic lipase would prevent the breakdown of triglyceride and delays the absorption of fatty acids into the systemic circulation and adipocytes. Whilst, orlistat is the only conventional pancreatic lipase enzyme inhibitor available in clinics, identifying the safe clinical alternatives from plants to inhibit pancreatic lipase has been considered a significant advancement. Consequently, plants which have shown significant potential to combat obesity are now revisited for its abilities to inhibit pancreatic lipase. In this regard, our review surveyed the potential of medicinal plants and its phytoconstituents to inhibit pancreatic lipase and to elicit anti-obesity effects. Thus, the review collate and critically appraise the potential of medicinal plants and phyto-molecules inhibiting pancreatic lipase enzyme and consequently modulating triglyceride absorption in gut, and discuss its implications in the development of novel therapeutic strategies to combat obesity.

Pancreatic lipase inhibitory activity of selected pharmaceutical agents

Twenty-five structurally diverse compounds have been tested in vitro for their pancreatic lipase (PL) inhibitory activity. Despite the diversity of tested compounds, the relationship comprising structural attributes of the compounds could be established to correlate with the observed inhibitory activity. Compounds that exerted inhibitory action through surface activity were of different profile from the rest of compounds. When co-incubated with orlistat (OsT), important synergistic effects for some compounds (orphenadrine, gliclazide, cefuroxime and sulfacetamide) were revealed, while antagonistic effects were demonstrated for others (camphor sulfonic acid and dinitro salicylic acid). Docking studies for the most active molecules were performed and molecular interaction forces with the PL active site were identified. The results suggested co-binding of OsT along with the other inhibitor in the binding site in cases of synergistic effect but not in the case of antagonistic effect. These results were additionally supported by affinity capillary electrophoresis. In conclusion, synergistic lipase inhibitory activity between OsT and some other pharmaceutical compounds was demonstrated for the first time, which might help improve the pharmacological effect of OsT.

Natural anti-obesity agents and their therapeutic role in management of obesity: A future trend perspective

In the present scenario, obesity is a challenging health problem and its prevalence along with comorbidities are on the rise around the world. According to world health organization and organisation for economic co-operation and development epidemiology reports, overweight and obesity are the fifth foremost causes of deaths globally. The increasing rate of obesity is becoming a mammoth problem which enormously affects an individual's quality of life. The conventional therapy of obesity mainly involves synthetic moieties and surgical procedures, which has many harmful side effects and chances of recurrence with severity. Hence, the Present review is a metanalysis of all the available data on the use of the plants with their biological source, active phytochemical constituents and a probable mechanism of action as natural anti-obesity agents. The metanalysis of data during the period of 2000-2018 was performed with the help of scientific data search engine National Center for Biotechnology Information (NCBI/PubMed). This data reveals the need and scope of further research in the development of new natural phytoconstituents for the management of obesity.

Chemical Composition and Enzymatic Screening of Micromeria fruticosa serpyllifolia Volatile Oils Collected from Three Different Regions of West Bank, Palestine

INTRODUCTION

Volatile oils (VOs) have been commonly used in cosmetics and food as fragrances, flavoring, and preservative agents or in alternative medicine for their therapeutic effects. This necessitates investigating those plants and their VOs. This study was conducted to investigate the chemical compositions of the VOs of Micromeria fruticosa serpyllifolia growing widely in three regions in Palestine (i.e., Hebron, Ramallah, and Nablus districts representing south, middle, and north of West Bank). Afterwards, VOs were subjected to in vitro screening and their enzymatic properties were compared.

METHODS

The analysis of chemical components of VOs was performed by gas chromatography coupled with mass spectrometry (GC-MS). The antilipase activity was evaluated using porcine pancreatic lipase and p-nitrophenyl butyrate. The antiamylase activity was assessed using porcine pancreatic α-amylase, starch, and 3,5-dinitrosalicylic.

RESULTS

Plant extracts yield range was 0.67 to 0.99 w/w%. GC-MS analysis showed the high percentages of oxygenated components in the range of 86.1-89.88% and nonoxygenated components in the range of 4.38-4.71%. Seven components were observed, pulegone was the most abundant component in the three samples in the range of 74.43-86.04%, and isomenthone was the second most abundant component with the range of 3.16-14.41%. The sample collected from Nablus showed the most potent antilipase and antiamylase activity with IC50 values of 39.81 μg/mL and 3.31 μg/mL, respectively.

CONCLUSIONS

The study showed that Micromeria fruticosa serpyllifolia volatile oils samples from different regions in Palestine contained different proportions of phytochemicals which provided different potential biological activities such as antiobesity and antidiabetes activities that were in line with traditional uses of the plant extracts. The plant extracts showed higher antilipase and antiamylase potency than that of the relative references and there were significant differences in these activities compared to each other.

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.

Improvement of Animal Feed Additives of Ginkgo Leaves through Solid-state Fermentation using Aspergillus niger

To improve the quality of Ginkgo biloba leaves as biological feed additives, twelve Aspergillus niger strains were evaluated for their growth in the moisture ginkgo leaf meal media through solid-state fermentation. The results relating to flavor, flavonoids, enzymes, crude protein, and reducing sugars showed A. niger Gyx086 strain was capable of efficiently fermenting ginkgo leaves. The optimal cultural conditions were three loops of spores inoculation to every 75 g medium containing 60 % water, grew at 28˚C for 48 h. The Gyx086 grew well in the medium. The fermented leaves generated a strong sweet-smelling odor, could be identified by electronic nose equipment using a cluster analysis, other than the original offensive smell from non-fermented ginkgo leaves. Each gram dried culture with Gyx086 showed 2.83 × 10⁹ CFU of A. niger; 3.19 ± 0.37 FPU of acid-resistant filter paper activity. Its total contents of flavonoids, reducing sugars, and crude proteins were 19.95 ± 0.23 mg, 24.28 ± 2.35 mg, and 162.81 ± 3.46 mg in each gram of leaves, 26.03 %, 62.73 %, and 14.58 % higher than the controls, respectively. The essential amino acids and total amino acids contents were 96.41 % and 16.49 % higher than the controls.

Antiobesity and antihyperglycaemic effects of Adiantum capillus-veneris extracts: in vitro and in vivo evaluations

CONTEXT

Adiantum capillus-veneris L. (Adiantaceae) hypocholesterolemic activity is therapeutically praised.

OBJECTIVES

Pharmacological modulation of pancreatic triacylglycerol lipase (PL) and α-amylase/α-glucosidase by A. capillus-veneris are evaluated.

MATERIALS AND METHODS

Using positive controls (acarbose, orlistat, guar gum, atorvastatin, glipizide and metformin) as appropriate, crude aqueous extracts (AEs) of A. capillus-veneris aerial parts were tested via a combination of in vitro enzymatic (0.24-100 mg/mL), acute in vivo carbohydrate tolerance tests (125, 250 or 500 mg/kg body weight [b.wt]) and chronic in vivo studies (500 mg/kg b.wt) in high cholesterol diet (HCD) fed Wistar rats.

RESULTS

Like acarbose, A. capillus-veneris as well as chlorogenic acid, with respective IC₅₀ values (mg/mL) of 0.8 ± 0.0 and 0.2 ± 0.0, were identified as in vitro potent dual inhibitors of α-amylase/α-glucosidase. Unlike guar gum, A. capillus-veneris had no glucose diffusion hindrance capacity. Equivalent to orlistat, A. capillus-veneris and its phytoconstituents inhibited PL in vitro with an ascending order of PL- IC₅₀ values (μg/mL): ferulic acid; 0.48 ± 0.06 < ellagic acid; 13.53 ± 1.83 < chlorogenic acid; 38.4 ± 2.8 < A. capillus-veneris; 1600 ± 100. Incomparable to acarbose or metformin and glipizide, A. capillus-veneris (125, 250 and 500 mg/kg b.wt) lacked antihyperglycaemic efficacies in acute starch- or glucose-evoked postprandial hyperglycaemia increments in normoglycaemic overnight fasting rats. Superior to atorvastatin; A. capillus-veneris exerted significant antiobesity (p < 0.001) with marked triacylglycerol-reducing capacities (p < 0.001) in comparison to rats fed with HCD for 10 weeks.

DISCUSSION AND CONCLUSION

A. capillus-veneris, modulating pancreatic digestive enzymes, may be advocated as a combinatorial diabesity prevention/phytotherapy agent.

Fungal endophytes associated with Viola odorata Linn. as bioresource for pancreatic lipase inhibitors

Background

As per the recent statistical reports of World Health Organisation (WHO), 13% of total global population is obese. Orlistat remains to be the only drug approved for the long term treatment of obesity. Recent findings highlighted severe adverse effects of orlistat that included hepatotoxicity, gall stones, kidney stones and acute pancreatitis. Therefore, search for new drug is required. The investigations based on endophytic natural products would prove pivotal in the global fight against this health issue.

Methods

Obesity is associated with lipid metabolism involving pancreatic lipase enzyme. The inhibition of pancreatic lipase is demonstrated by using the extracts of endophytes isolated from Viola odorata Linn. In addition, endophytes were identified using ITS based rDNA sequencing.

Results

Present study involves the isolation and identification of 27 endophytes from V. odorata. All the endophytes were evaluated for lipase inhibitory activities. The extracts of seven endophytes exhibited lipase inhibitory activity with IC₅₀ < 10 μg/mL. The extract of VOLF4 (Aspergillus sp.) displayed promising lipase inhibitory activity (IC₅₀ 3.8 μg/mL).

Conclusion

The present study demonstrates that V. odorata harbors endophytic community with potent lipase inhibitory activity. VOLF4 is the potential endophyte. The extract of VOLF4 can be used to develop the potential drug to treat obesity.

Antilipase and antiproliferative activities of novel fluoroquinolones and triazolofluoroquinolones

Fluoroquinolones (FQs) have been identified recently as potent inhibitors of pancreatic lipase (PL). The aim of this study was to synthesize novel FQs and triazolofluoroquinolones (TFQs) and to evaluate them in vitro with respect to their antilipolytic efficacy and potency properties. The PL-IC₅₀ values of 12 FQs and TFQs (3 (a-c)-6 (a-c)) were in the range of 12.5-189.1 μm. These values are further supported by docking studies. The suggested association between obesity and colorectal cancer initiated the evaluation of antiproliferative activity of the new FQs and TFQs against a panel of obesity-related colorectal cells (HT29, HCT116, SW620 CACO2, and SW480). Sulforodamine B colorimetric assay revealed that some derivatives exhibited unselective cytotoxicity against HT29, HCT116, SW620 CACO2, and SW480. Remarkably, FQ 4a's selective cytotoxicity against HCT116 was found valuable with IC₅₀ value of 4.2 μm which exceeds that of cisplatin with a substantial selective cytotoxicity in periodontal ligament fibroblasts. In conclusion, FQ and TFQ derivatives may unveil new antiobesity and anticancer agents in the future.

Potential Lipid-Lowering Effects of Eleusine indica (L) Gaertn. Extract on High-Fat-Diet-Induced Hyperlipidemic Rats

Background:

To date, anti-obesity agents based on natural products are tested for their potential using lipase inhibition assay through the interference of hydrolysis of fat by lipase resulting in reduced fat absorption without altering the central mechanisms. Previous screening study had indicated strong anti-obesity potential in Eleusine indica (E. indica), but to date, no pharmacologic studies have been reported so far.

Objective:

This study was performed to investigate the lipid-lowering effects of E. indica using both in vitro and in vivo models.

Methods:

The crude methanolic extract of E. indica was fractionated using hexane (H-Ei), dichloromethane (DCM-Ei), ethyl acetate (EA-Ei), butanol (B-Ei), and water (W-Ei). All the extracts were tested for antilipase activity using porcine pancreatic lipase. Because H-Ei showed the highest inhibition, it was further subjected to chemical profiling using high-performance liquid chromatography. Subsequently, oral toxicity analysis of H-Ei was performed [Organization for Economic Cooperation and Development guidelines using fixed dose procedure (No. 420)]; efficacy analysis was performed using high-fat diet (HFD)-induced hyperlipidemic female Sprague–Dawley rats.

Results:

According to the toxicity and efficacy analyses, H-Ei did not demonstrate any noticeable biochemical toxicity or physiologic abnormalities and did not cause any tissue damage as per histologic analysis. Furthermore, H-Ei significantly reduced body weight and improved serum profile and did not show hepatotoxicity and nephrotoxicity based on the serum profile. Moreover, H-Ei alleviated HFD-induced hepatosteatosis and ameliorated induced adiposity in both visceral and subcutaneous adipose tissue.

Conclusion:

Our results demonstrate that H-Ei effectively improved hyperlipidemia. Further studies to explore its possibility as an alternative pharmacologic agent to treat obesity are warranted.

SUMMARY

Hexane extract of Eleusine indica (H-Ei) showed strong potential in the inhibition of porcine pancreatic lipase (27.01 ± 5.68%).

The acute oral toxicity of E. indica hexane extract on animal model falls into Globally Harmonized System Category 5 (low hazard), since mortality, clinical toxicity symptoms, gross pathologic, or histopathologic damage was not observed.

The hexane extract of E. indica had significantly reduced the body weight and improved serum lipid profile, with reduction in serum triglycerides, total cholesterol, low-density lipoprotein, and elevation in high-density lipoprotein when comparing against the high-fat diet control group.

Microscopic evaluation on histologic slides of liver and adipose tissues suggested that E. indica hexane extract had greatly improved liver steatosis and adipose tissue hypertrophy in high-fat diet control group.

Abbreviation used: ALT: Alanine transaminase; AST: Aspartate transaminase; B-Ei: Butanol extract of E. indica; DCM-Ei: Dichloromethane extract of E. indica; EA-Ei: Ethyl acetate extract of E. indica; GHS: Globally Harmonized System; HDL: High-density lipoprotein; H-Ei: Hexane extract of E. indica; HFD: High-fat diet; HPLC: High-performance liquid chromatography; LDL: Low-density lipoprotein; NFD: Normal fed diet; PPL: Porcine pancreatic lipase; SEM: Standard error of mean; SD: Standard deviation; TC: Total cholesterol; TG: Triglycerides; W-Ei: Water extract of E. indica.

Natural Products with Anti-obesity Effects and Different Mechanisms of Action

Obesity, a primary influence on health condition, causes numerous comorbidities and complications and, therefore, pharmacotherapy is considered a strategy for its treatment. However, the adverse effects of most chemical drugs targeting weight loss complicate their approval by regulatory authorities. Recently, interest has increased in the development of ingredients from natural sources with fewer adverse effects for preventing and ameliorating obesity. This review provides an overview of current anti-obesity drugs and natural products with anti-obesity properties as well as their mechanisms of action, which include interfering with nutrient absorption, decreasing adipogenesis, increasing energy expenditure (thermogenesis), appetite suppression, modifying intestinal microbiota composition, and increasing fecal fat excretion.

Synthesis, evaluation and molecular modelling studies of 2-(carbazol-3-yl)-2-oxoacetamide analogues as a new class of potential pancreatic lipase inhibitors

A series of twenty four 2-(carbazol-3-yl)-2-oxoacetamide analogues were synthesized, characterized and evaluated for their pancreatic lipase (PL) inhibitory activity. Porcine PL was used against 4-nitrophenyl butyrate (method A) and tributyrin (methods B and C) as substrates during the PL inhibition assay. Compounds 7e, 7f and 7p exhibited potential PL inhibitory activity (IC₅₀ values of 6.31, 8.72 and 9.58μM, respectively in method A; and X_i50 of 21.85, 21.94 and 26.2, respectively in method B). Further, inhibition kinetics of 7e, 7f and 7p against PL, using method A, revealed their competitive nature of inhibition. A comparison of the inhibition profiles of the top three compounds in methods B and C, provided a preliminary idea of covalent bonding of the compounds with Ser 152 of PL. Molecular docking studies of the compounds 7a-x into the active site of human PL (PDB ID: 1LPB) was in agreement with the in vitro results, and highlighted probable covalent bond formation with Ser 152 apart from hydrophobic interactions with the lid domain. Molecular dynamics simulation of 7e complexed with PL, further confirmed the role of aromatic groups in stabilising the ligand (RMSD ⩽4Å). The present study led to the identification of 2-(carbazol-3-yl)-2-oxoacetamide analogues 7a-x as a new class of potential PL inhibitors.

In vitro investigation of the potential health benefits of wild Mediterranean dietary plants as anti-obesity agents with α-amylase and pancreatic lipase inhibitory activities

BACKGROUND

Inhibition of digestive enzymes is one of the most widely studied mechanisms used to determine the potential efficacy of natural products as anti-obesity agents. In vitro studies reported here were performed to evaluate the inhibitory activity of formulations of edible plants from Italy on amylase and lipase by monitoring the hydrolysis of nitrophenyl caprilate and the hydrolysis of glycoside bonds in digestible carbohydrate foods.

RESULTS

The formulation obtained from Capparis sicula exhibited the strongest inhibitory effect on pancreatic lipase (IC50 = 0.53 mg mL(-1) ) while the Borago officinalis formulation exhibited the strongest inhibitory effect on α-amylase (IC50 = 31.61 µg mL(-1) ). In order to characterise the extracts, high-performance thin-layer chromatography analysis of the formulations was performed, revealing the predominance of (±)-catechin in Mentha aquatica formulation, rutin in C. sicula, and caffeic acid and chlorogenic acid in Echium vulgare.

CONCLUSION

The results obtained indicated that the extracts of C. sicula and B. officinalis could be good candidates for further studies to isolate pancreatic lipase and α-amylase inhibitors, respectively.