Structure-activity relationship of dietary flavonoids on pancreatic lipase

Molecular mechanisms of naringin's high lipid-lowering activity: pancreatic lipase inhibition and fat accumulation reduction

BACKGROUND

Naringin, a natural flavonoid compound, has demonstrated potential anti-obesity effects by modulating lipid metabolism. Pancreatic lipase plays a critical role in lipid digestion and absorption, making it a key target for obesity management. This study investigated the inhibitory mechanism of naringin on pancreatic lipase through in vitro, in vivo, and in silico experiments.

RESULTS

In vitro experiments revealed that naringin was a competitive inhibitor of pancreatic lipase, with a half-maximal inhibitory concentration (IC₅₀) of 6.93 ± 0.12 mmol/L. Multi-fluorescence spectroscopy confirmed that naringin induced secondary structure changes and static fluorescence quenching of pancreatic lipase, with a binding constant of 2.16 × 104 L/mol. Isothermal titration calorimetry indicated a spontaneous exothermic reaction (-26.08 kJ/mol), mainly driven by hydrogen bonding and electrostatic force. In vivo studies demonstrated that naringin decreased serum lipase activity by 24.54%, mitigated hepatic lipid accumulation, and down-regulated inflammatory cytokines in high-fat diet-induced obese rats. Molecular simulation further revealed that hydrogen bonding was the primary interaction force between naringin and pancreatic lipase.

CONCLUSIONS

Naringin effectively inhibits pancreatic lipase through competitive binding and structural modifications, reducing lipid digestion and absorption. The inhibitory effect of naringin on pancreatic lipase might provide new insights into the role of naringin in lipid metabolism regulation and potential application in obesity management. © 2025 Society of Chemical Industry.

Lipid-lowering effect of mangiferin through the inhibition of pancreatic lipase activity

BACKGROUND

The inhibition of pancreatic lipase activity to reduce dietary lipid absorption is an effective strategy to combat obesity. Mangiferin, a bioactive flavonoid derived from Mangifera indica, exhibits potent lipid-lowering potential. However, although its in vitro inhibitory effect on pancreatic lipase has been identified, the underlying mechanism remains poorly understood. Direct in vivo evidence of its impact on dietary lipid absorption is also lacking. This study aimed to elucidate the mechanism of mangiferin's inhibition of pancreatic lipase through in vitro inhibitory kinetics assays and in silico molecular docking analysis. Its effects on dietary lipid absorption were also evaluated in a mouse model of high-fat diet (HFD)-induced obesity.

RESULTS

Inhibitory kinetics assays demonstrated that mangiferin inhibited pancreatic lipase in a reversible, non-competitive manner, with a half- maximal inhibitory concentration (IC50) of 82.31 μmol L-1. Molecular docking showed that mangiferin bound to the enzyme's allosteric site through hydrogen bonds with Glu-188, Arg-191, Gln-22, and Val-21 residues, consistent with non-competitive inhibition. In vivo studies revealed that administration of 200 mg kg-1 body weight of mangiferin alleviated HFD-induced obesity, hepatic steatosis, and hyperlipidemia significantly. Notably, mangiferin increased fecal lipid excretion by 52.5%, which was significant, indicating reduced dietary lipid absorption.

CONCLUSION

These findings suggest that mangiferin is a promising pancreatic lipase inhibitor, which may reduce dietary lipid absorption, contributing, at least partially, to its lipid-lowering effects. © 2025 Society of Chemical Industry.

Targeting diabetes with flavonoids from Indonesian medicinal plants: a review on mechanisms and drug discovery

The rich biodiversity of Indonesia provides a wide variety of plants rich in flavonoids, which show promising potential as antidiabetic agents. Flavonoids are polyphenolic compounds recognized for their broad biological activities, such as antioxidant, anti-inflammatory, and antidiabetic effects. Traditional Indonesian medicinal plants such as Syzygium cumini, Moringa oleifera, and Curcuma longa are currently being studied for their flavonoid content and potential in diabetes treatment. Studies suggest that flavonoids can influence crucial pathways in diabetes management, including enhancing insulin sensitivity, boosting insulin production, and safeguarding pancreatic β cells against damage caused by oxidative stress. For example, quercetin and kaempferol, flavonoids in many Indonesian plants, have demonstrated potential for managing glucose metabolism and lowering high blood sugar levels. Additionally, these substances have been shown to inhibit enzymes such as α-glucosidase and α-amylase, which are involved in the breakdown of carbohydrates, thus aiding in the regulation of blood sugar levels after meals. The antioxidant qualities of flavonoids play a crucial role in fighting oxidative stress and are a significant contributor to the development of diabetes and related complications. Flavonoids help neutralize free radicals and enhance the body's antioxidant protection, reducing oxidative harm and promoting metabolic wellness. Additionally, their anti-inflammatory properties aid in reducing the chronic inflammation linked to insulin resistance and β-cell dysfunction. Formulation advancements, such as nanocarrier technology, have been explored to boost the effectiveness of flavonoid-based therapies. Due to its vast plant diversity, Indonesia offers a potential reservoir for new antidiabetic drugs, meriting additional research and development with the aim of this review providing new knowledge on the potential of flavonoids that can play a role in the treatment of diabetes.

Enzymatic Deglycosylation and Lipophilization of Soy Glycosides into Value-Added Compounds for Food and Cosmetic Applications

Soybean is one of the most important crops worldwide, being placed ninth on the chart of the most cultivated species. Its high level of production correlates with a huge amount of waste produced. These residues could be of great interest due to the presence of high-value-added molecules, including some glycosides (i.e., daidzin, genistin, glycitin) widely studied for their potent antioxidant properties. Due to their low bioavailability and limited solubility in lipidic media, lipophilization strategies have recently gained momentum to improve daidzin, genistin, and glycitin applications as multifunctional additives in the food, pharmaceutical, and cosmetic sectors. In this context, starting from soybean glycosides, we followed two parallel approaches, i.e., hydrolysis to obtain the corresponding aglycones possessing a better pharmacokinetic profile and esterification of the sugar primary alcohol with short-chain fatty acids. First, homemade extremophilic glycosidase (HOR) from Halothermothrix orenii has been employed for the preparation of aglycones (molar conversion 96-99%) in both water and biphasic media (water/2,2,5,5-tetramethyloxolane 1:1). Subsequently, lipophilization reactions with butanoic, hexanoic, and octanoic acids have been carried out using commercially available immobilized lipase B from Candida antarctica (CaLB) under flow conditions to produce modified glycosides with better physicochemical properties to be implemented in cosmetic preparations. Noteworthily, compared to the batch methodology, compound 1 (6-O-octanoildaidzin) was obtained with a drastic reduction in reaction time (30 min vs 18 h) and a consequent 9-fold increase in specific reaction rates (0.15 vs 0.017 μmol/(min·g)).

Ultrasound-enzyme-assisted extraction of flavonoids, polysaccharides, and triterpenes from Gualou and Xiebai: optimization, bioactivity, in vitro digestive stability, and impact on lipid digestion

Gualou (Trichosanthes kirilowii Maxim) and Xiebai (Allium macrostemon Bunge) have been extensively studied for their diverse active ingredients, which include flavonoids, polysaccharides, and triterpenoids. This study employed a single-factor experiment alongside the Plackett-Burman design and utilized response surface methodology to optimize the ultrasonic-enzyme-assisted extraction (U-EAT) method for the functional components in Gualou and Xiebai (GLXB). The optimal extraction conditions were identified as a solid-to-liquid ratio of 1:11 g/mL, an alcohol concentration of 55%, an enzyme concentration of 1.2%, and an extraction temperature of 40°C. The yields of flavonoids, polysaccharides, and triterpenoids obtained were 0.94 ± 0.05, 260.46 ± 1.78, and 118.69 ± 0.71 mg/g, respectively, demonstrating increases of 59.19%, 29.03%, and 46.10% compared to HL (HL, the traditional reflux extraction method). Furthermore, in vitro digestion of the GLXB extract demonstrated significant lipid-lowering and hypoglycemic effects. The GLXB extract facilitated the flocculation of lipid droplets during lipid digestion and exhibited the capacity to reduce the rate of fat digestion. These findings indicate that the U-EAT significantly enhanced the content of active ingredients in GLXB and improved the hypoglycemic and lipid-lowering activities of the GLXB extract, highlighting its potential for further development and application in functional foods.

Flavonoids for gastrointestinal tract local and associated systemic effects: A review of clinical trials and future perspectives

BACKGROUND

Flavonoids are naturally occurring dietary phytochemicals with significant antioxidant effects aside from several health benefits. People often consume them in combination with other food components. Compiling data establishes a link between bioactive flavonoids and prevention of several diseases in animal models, including cardiovascular diseases, diabetes, gut dysbiosis, and metabolic dysfunction-associated steatotic liver disease (MASLD). However, numerous clinical studies have demonstrated the ineffectiveness of flavonoids contradicting rodent models, thereby challenging the validity of using flavonoids as dietary supplements.

AIM OF REVIEW

This review provides a clinical perspective to emphasize the effective roles of dietary flavonoids as well as to summarize their specific mechanisms in animals briefly.

KEY SCIENTIFIC CONCEPTS OF REVIEW

First, this review offers an in-depth elucidation of the metabolic processes of flavonoids within human, encompassing the small, large intestine, and the liver. Furthermore, the review provides a comprehensive overview of the various functions of flavonoids in the gastrointestinal tract, including hindering the breakdown and assimilation of macronutrients, such as polysaccharides and lipids, regulating gut hormone secretion as well as inhibition of mineral iron absorption. In the large intestine, an unabsorbed major portion of flavonoids interact with the gut flora leading to their biotransformation. Once absorbed and circulated in the bloodstream, bioactive flavonoids or their metabolites exert numerous beneficial systemic effects. Lastly, we examine the protective effects of flavonoids in several metabolic disorders, including endothelial dysfunction, MASLD, cardiovascular disease, obesity, hyperlipidemia, and insulin resistance. In conclusion, this review outlines the safety and future prospects of flavonoids in the field of health, especially in the prevention of metabolic syndrome (MetS).

The Impact of Cooking on Antioxidant and Enzyme Activities in Ruichang Yam Polyphenols

In this study, the total polyphenol content (TPC), total flavonoid content (TFC), and biological activity of yam polyphenols (including free phenolics, conjugated phenolics, and bound phenolics) were investigated during home cooking. Polyphenol components were preliminary detected in raw yam by HPLC, including 2, 4-dihydroxybenzoic acid, syringic acid, vanillic acid, 4-coumaric acid, and sinapic acid. TPC and TFC of soluble conjugated polyphenols were the main phenolic compounds in Ruichang yam. Compared with uncooked yam, cooking times of 80 min and 40 min increased the TPC and TFC of multiple types of polyphenols, while cooking reduced the TPC and TFC of AHP (acid-hydrolyzed soluble conjugated polyphenols). All yam polyphenols exhibited good α-Glucosidase inhibitory activity; α-Glucosidase inhibitory activity was significantly higher for a cooking time of 120 min. Only some types of polyphenols had lower pancreatic lipase half-inhibition concentrations than orlistat when cooked. The pancreatic lipase of FPs (free polyphenols), BHPs (alkali-hydrolyzed soluble conjugated polyphenols), and ABPs (acid-hydrolyzed insoluble bound polyphenols) was the stronges when cooking for 80 min, and the pancreatic lipase inhibitory activity of AHPs and BBPs (alkali-hydrolyzed insoluble bound polyphenols) was strongest when cooking for 40 min. Pearson's correlation coefficient analysis revealed that the TPC was positively correlated with the TFC, the IC50 value of α-Glucosidase was negatively correlated with the IC50 value of pancreatic lipase, and redox activity was positively correlated with the TPC and TFC, respectively.

Exploration of the Mechanism of Guaijaverin in Inhibiting Pancreatic Lipase Based on Multispectral Method, Molecular Docking, and Oral Lipid Tolerance Test in Rats

This study aims to investigate the action mechanism of guaijaverin on pancreatic lipase from multiple perspectives and provide a theoretical basis for the search for new pancreatic lipase inhibitors. The inhibition of pancreatic lipase by guaijaverin was investigated through enzyme inhibition activity experiments, and the IC50 was calculated to determine the type of inhibition of guaijaverin. The mechanism of action was studied by measuring fluorescence, ultraviolet spectra, and circular dichroism. Molecular docking technology was used to explore the binding situation. In addition, in vivo oral lipid tolerance tests in rats were carried out to investigate the inhibitory effect of guaijaverin on pancreatic lipase. Guaijaverin inhibited pancreatic lipase up to 90.63%, confirming its excellent inhibitory ability. The inhibition type was noncompetitive inhibition in reversible inhibition. The multispectral experiments indicated that its quenching type was static quenching and guaijaverin changed the microenvironment and spatial conformation of pancreatic lipase. The molecular docking results showed that the minimum binding energy between the two compounds was -6.96 kcal/mol. In vivo experiments demonstrated that guaijaverin inhibits pancreatic lipase by reducing TG uptake in the body. Guaijaverin has excellent inhibitory effects on pancreatic lipase and has the potential to function as a pancreatic lipase inhibitor.

Comparative Evaluation of Micellization and Cellular Uptake of β-Carotene Affected by Flavonoids

Based on in vitro digestion, micellar synthesis, and Caco-2 cell model, this study investigated the effects of typical flavonoids in citrus (naringenin, naringin, hesperetin, hesperidin, quercetin, and rutin) at different doses on the micellization and cellular uptake of β-carotene. In in vitro digestion, low-dose flavonoids enhanced β-carotene bioaccesssibility by regulating the stability and dispersibility of the intestinal medium, particularly quercetin, which significantly increased the bioaccessibility by 44.6% (p < 0.05). Furthermore, naringenin, hesperetin, hesperidin, and quercetin enhanced the micellar incorporation rate of β-carotene; however, naringin and rutin exhibited an opposite effect, particularly naringin, which significantly reduced it by 71.3% (p < 0.05). This phenomenon could be attributed to the high solubility of naringin and rutin in micelles, resulting in a competitive inhibitory effect on β-carotene. Besides, all treatments significantly enhanced β-carotene cellular uptake (p < 0.05) by promoting the expression of scavenger receptor class B type I and Niemann-Pick C1-Like 1.

Nutraceutical Properties of the Hydroalcoholic Extract and Phenolic Compounds from Yucca aloifolia Edible Flowers

The flowers of Yucca aloifolia ("flor de izote") are considered a millenary food in the Northeastern Highlands of Puebla, Mexico. The present investigation reports on the chemical and biological activities of the hydroalcoholic extract (YAHF) obtained from this edible source. HPLC-MS profiling revealed twenty bioactive phenolic compounds with chlorogenic acid (16.5 mg g-1 DW), quercetin (9.5 mg g-1 FW), and their glycosides (rutin and quercitrin), as well as caffeic acid (8.4 mg g-1 DW) and ferulic acid (7.9 mg g-1 DW) as major compounds dissolved in YAHF. Six metabolites had potent anti-lipase (IC50<100 μg mL-1) and anti-ornithine decarboxylase activity (IC50<100 μg mL-1), whereas thirteen exerted strong anti-alpha-glucosidase properties (IC50<100 μg mL-1). The evaluation of YAHF in mice subjected to standard oral glucose tolerance tests and prolonged administration of hypercaloric/atherogenic diet (30 days), unraveled their ability to improve glucose and lipid profiles. YAHF and six phenolic compounds significantly reduced DLD-1 cell viability (IC50, 117.9 μg mL-1) and avoided polyamine accumulation linked to anti-ornithine decarboxylase activity. YAHF and its twenty constituents exerted low toxicity in probiotics (>1000 μg mL-1) and 3T3 fibroblasts (>2.5 mg-mL-1), sustaining their safeness for human consumption.

Dynamics changes in metabolites and pancreatic lipase inhibitory ability of instant dark tea during liquid-state fermentation by Aspergillus niger

Instant dark tea (IDT), prepared by liquid-state fermentation using Aspergillus niger, is known for its high theabrownins content and lipid-lowering effect. To explore the impact of fungal fermentation on IDT compositions and its pancreatic lipase inhibitory ability (PLIA), untargeted and targeted metabolomic analysis were applied to track the changes of metabolites over a 9-day fermentation period, and correlation analysis was then conducted between metabolites and PLIA of IDT. There were 54 differential metabolites exhibited significant changes from day 3 to day 5 of fermentation. The concentrations of theabrownins and caffeine increased during fermentation, while phenols and free amino acids decreased. The PLIA of IDT samples significantly increased from day 5 to day 9 of fermentation. Theabrownins not only positively correlated with the PLIA but also exhibited a high inhibition rate. These findings provide a theoretical basis to optimize the production of IDT as functional food ingredient.

Refining quinoa storage stability through microwave-induced structural alterations and activity suppression of key enzymes

This study investigated the effects of microwave on preserving the quality of quinoa during storage. Quinoa treated with 9W/60s exhibited a significant decrease in fatty acid values compared to hot air treatment. Microwave effectively delayed lipid oxidation during quinoa storage by suppressing the increase in peroxide values. MDA gradually accumulated from peroxides during storage, reaching its peak at 0.423 μmol/L in the second week. Microwave disrupted the original hydrogen bonds in lipase, causing the unwinding of the α-helix and resulting in the loss of its regular structure. Microwave reduced the stability of the β-sheet structure in lipoxygenase, breaking the natural secondary structure composition. The observed fluorescence and UV spectra features were similar, indicating that microwave alter the peptide chain of the enzyme's skeletal structure, increasing the exposure of hydrophobic chromophores. These results indicated the potential of microwave to enhance the stability of quinoa during storage.

Inhibitory effects of nobiletin-mediated interfacial instability of bile salt emulsified oil droplets on lipid digestion

Previous lipase inhibitors studies mainly focus on the binding between inhibitors and lipase, ignoring the impact of inhibitors on the oil-water interface of lipid droplets. This study aimed to investigate the effect of nobiletin (NBT) from Citri Reticulatae Pericarpium on the oil-water interface properties and lipid digestion. Here, we found that NBT could destroy bile salt (BS)-stabilized lipid droplets and thus inhibited free fatty acid release, owing to the interaction between NBT and BS at the oil-water interface, and reducing the stability of the oil-water interface (the stability index decreased from 91.15 ± 2.6 % to 66.5 ± 3.6 %). Further, the molecular dynamics simulation and isothermal titration calorimetry revealed that NBT could combine with BS at oil-water interface through intermolecular interactions, including hydrogen bonds, Van der Waals force, and steric hindrance. These results suggest that the interfacial instability of NBT mediated BS emulsified oil droplets may be another pathway to inhibit lipid digestion.

A narrative review on the mechanism of natural flavonoids in improving glucolipid metabolism disorders

Glucolipid metabolism disorder (GLMD) is a complex chronic disease characterized by glucose and lipid metabolism disorders with a complex and diverse etiology and rapidly increasing incidence. Many studies have identified the role of flavonoids in ameliorating GLMD, with mechanisms related to peroxisome proliferator-activated receptors, nuclear factor kappa-B, AMP-activated protein kinase, nuclear factor (erythroid-derived 2)-like 2, glucose transporter type 4, and phosphatidylinositol-3-kinase/protein kinase B pathway. However, a comprehensive summary of the flavonoid effects on GLMD is lacking. This study reviewed the roles and mechanisms of natural flavonoids with different structures in the treatment of GLMD reported globally in the past 5 years and provides a reference for developing flavonoids as drugs for treating GLMD.

Evaluation of antioxidant, antidiabetic and antiobesity potential of phenylpropanoids (PPs): Structure-activity relationship and insight into action mechanisms against dual digestive enzymes by comprehensive technologies

Phenylpropanoids (PPs), a group of natural compounds characterized by one or more C6-C3 units, have exhibited considerable potential in addressing metabolic disease. However, the comprehensive investigation on the relationship of compound structures and involved activity, along with the action mechanisms on the drug target is absent. This study aimed to evaluate the antioxidant and inhibitory activities of 16 PPs against two digestive enzymes, including α-glucosidase and pancreatic lipase, explore the structure-activity relationships and elucidate the mechanisms underlying enzyme inhibition. The findings revealed the similarities in the rules governing antioxidant and enzyme inhibitory activities of PPs. Specifically, the introduction of hydroxyl groups generally exerted positive effects on the activities, while the further methoxylation and glycosylation were observed to be unfavorable. Among the studied PPs, esculetin exhibited the most potent antioxidant activity and dual enzymes inhibition potential, displaying IC50 values of 0.017 and 0.0428 mM for DPPH and ABTS radicals scavenging, as well as 1.36 and 6.67 mM for α-glucosidase and lipase inhibition, respectively. Quantification analysis indicated esculetin bound on both α-glucosidase and lipase successfully by a mixed-type mode. Further analyses by UV-Vis, FT-IR, fluorescence spectra, surface hydrophobicity, SEM, and molecular docking elucidated that esculetin could bind on the catalytic or non-catalytic sites of enzymes to form complex, impacting the normal spatial conformation for hydrolyzing the substrate, thus exhibiting the weakened activity. These results may shed light on the utilization value of natural PPs for the management of hyperglycemia and hyperlipemia, and afford the theoretical basis for designing drugs with stronger inhibition against the dual digestive enzymes based on esculetin.

Inquiry lipaseoring the mechanism of pancreatic lipase inhibition by isovitexin based on multispectral method and enzyme inhibition assay

Isovitexin is a main natural flavonoid component in various plants. Currently, the inhibitory effect of isovitexin on pancreatic lipase (PL) and its mechanism have not been elucidated yet. In the present study, we investigated the inhibitory effect of isovitexin on PL, as well as its interaction mechanism, using enzyme inhibition methods, spectroscopic analysis, and molecular simulations. Results showed that isovitexin possessed significant PL inhibitory activity, with IC50 values of 0.26 ± 0.02 mM. The interaction between isovitexin and PL was dominated by static quenching, and mainly through hydrogen bonding and hydrophobic interaction forces. Analysis of fluorescence spectroscopy confirmed that isovitexin binding altered the conformation of the PL. Circular dichroism (CD) spectrum indicated that isovitexin altered the secondary structure of PL by decreasing the α-helix content and increasing the β-fold content. Molecular simulations further characterize the conformational changes produced by the interaction between isovitexin with PL. The performed study may provide a new insight into the inhibitory mechanism of isovitexin as a novel PL inhibitor.

Chemical Profile and Bioactivity of Rubus idaeus L. Fruits Grown in Conventional and Aeroponic Systems

Raspberry (Rubus idaeus L.) is a fruit of great interest due to its aroma, nutritional properties, and the presence of many bioactive compounds. However, differences among cultivation systems can affect its composition and, consequently, its potential bioactivity. Herein, for the first time, raspberries grown in an aeroponic system were investigated for their chemical profile and antioxidant and anti-inflammatory activity, as well as their enzyme (α-glucosidase and pancreatic lipase) inhibitory properties in comparison to wild and conventionally cultivated fruits. High-performance liquid chromatography coupled with diode array detection (HPLC-DAD) analyses revealed the presence of gallic acid, caffeic acid, chlorogenic acid, p-coumaric acid, ferulic acid, rutin, and catechin in all the samples. The extracts exhibited in vitro anti-inflammatory activity (inhibition of nitric oxide production) regardless of the cultivation method. Of particular interest is the ability of raspberries to inhibit pancreatic lipase. With the exception of the β-carotene bleaching test, the raspberries grown in conventional and aeroponic systems were more active in terms of antioxidants than wild fruits, as evidenced by the ABTS (IC50 in the range 1.6-3.4 μg/mL), DPPH (IC50 in the range 8.9-28.3 μg/mL), and FRAP tests (24.6-44.9 μM Fe(II)/g). The raspberries from aeroponic cultivation were generally able to exert the same bioactivity as those obtained from both conventionally cultivated and wild fruits, supporting the consideration that in the future, this technology could reshape agriculture by mitigating resource constraints, fostering sustainable practices and increasing yields.

Combined Application of Fluorescence Spectroscopy and Principal Component Analysis in Characterisation of Selected Herbhoneys

This study reports the use of front-face fluorescence spectroscopy with principal component analysis (PCA) as a tool for the characterisation of selected Polish herbhoneys (raspberry, lemon balm, rose, mint, black current, instant coffee, pine, hawthorn, and nettle). Fluorimetric spectra registered in the ranges ascribed to fluorescence of amino acids, polyphenols, vitamins, and products of Maillard's reaction enabled the comparison of herbhoney compositions. Obtained synchronous spectra combined with PCA were used to investigate potential differences between analysed samples and interactions between compounds present in them. The most substantial influence on the total variance had the intensities of polyphenols fluorescence. These intensities were the main factor differentiated by the analysed products.

A polyphenol-rich plant extract prevents hypercholesterolemia and modulates gut microbiota in western diet-fed mice

Introduction

Totum-070 is a combination of five plant extracts enriched in polyphenols to target hypercholesterolemia, one of the main risk factors for cardiovascular diseases. The aim of this study was to investigate the effects of Totum-070 on cholesterol levels in an animal model of diet-induced hypercholesterolemia.

Methods

C57BL/6JOlaHsd male mice were fed a Western diet and received Totum-070, or not, by daily gavage (1g/kg and 3g/kg body weight) for 6 weeks.

Results

The Western diet induced obesity, fat accumulation, hepatic steatosis and increased plasma cholesterol compared with the control group. All these metabolic perturbations were alleviated by Totum-070 supplementation in a dose-dependent manner. Lipid excretion in feces was higher in mice supplemented with Totum-070, suggesting inhibition of intestinal lipid absorption. Totum-070 also increased the fecal concentration of short chain fatty acids, demonstrating a direct effect on intestinal microbiota.

Discussion

The characterization of fecal microbiota by 16S amplicon sequencing showed that Totum-070 supplementation modulated the dysbiosis associated with metabolic disorders. Specifically, Totum-070 increased the relative abundance of Muribaculum (a beneficial bacterium) and reduced that of Lactococcus (a genus positively correlated with increased plasma cholesterol level). Together, these findings indicate that the cholesterol-lowering effect of Totum-070 bioactive molecules could be mediated through multiple actions on the intestine and gut microbiota.

Chemical profile of Roselle extract and its inhibitory activities on three digestive enzymes in vitro and in vivo

Roselle is rich in an extensive diversity of beneficial substances, including phenolic acids, amino acids, anthocyanins, vitamins, and flavonoids. Herein, the chemical constituents in Roselle extract (RE) were identified by UPLC-DAD-QTOF-MS. Besides, its inhibitory effects on three digestive enzymes, i.e. α-amylase, α-glucosidase, and pancreatic lipase, were investigated in both in vitro and in vivo. Thirty-three constituents including hibiscus acid, 18 phenolic acids, 2 anthocyanins and 12 flavonoids were identified. The anthocyanins content in RE was 21.44 ± 0.68 %, while the contents of chlorogenic acids, rutin and quercetin were 17.76 ± 2.28 %, 0.31 ± 0.01 % and 0.32 ± 0.01 %, respectively. RE inhibited pancreatic lipase in a non-competitive way with an IC50 value of 0.84 mg/mL. Besides, it demonstrated a mixed-type inhibition on both α-glucosidase and α-amylase with IC50 values of 0.59 mg/mL and 1.93 mg/mL, respectively. Fluorescence quenching assays confirmed the binding of RE to the enzyme proteins. Furthermore, rats pre-treated with RE at doses of 50 and 100 mg/kg body weight (bwt) exhibited significant reductions in fat absorption and improvements in fat excretion through feces. Additionally, the in vivo study revealed that RE was effective in suppressing the increase of blood glucose after starch consumption, while its effects on maltose and sucrose consumption were relatively weak.

Lavandula angustifolia mill. (Lamiaceae) ethanol extract and its main constituents as promising agents for the treatment of metabolic disorders: chemical profile, in vitro biological studies, and molecular docking

Lavandula angustifolia Mill. (lavender) is one of the most used medicinal plants. Herein, we chemically characterised and investigated the antioxidant properties and the capability to inhibit key enzymes for the treatment of type 2 diabetes (TD2) and obesity such as pancreatic lipase, α-glucosidase, and α-amylase of the ethanolic extract of two lavender samples (La1 and La2) from southern Italy. Both extracts significantly inhibited α-glucosidase, while La1 inhibited α-amylase and lipase more effectively than La2. To investigate whether these properties could be due to a direct interaction of the main constituents of the extracts with the targeted enzymes, molecular docking studies have been performed. As a result, the selected compounds were able to interact with the key residues of the binding site of the three proteins, thus supporting biological data. Current findings indicate the new potential of lavender ethanolic extract for the development of novel agents for T2D and obesity.

Construction of a QSAR Model Based on Flavonoids and Screening of Natural Pancreatic Lipase Inhibitors

Pancreatic lipase (PL) is a key hydrolase in lipid metabolism. Inhibition of PL activity can intervene in obesity, a global sub-health disease. The natural product is considered a good alternative to chemically synthesized drugs due to its advantages, such as low side effects. However, traditional experimental screening methods are labor-intensive and cost-consuming, and there is an urgent need to develop high-throughput screening methods for the discovery of anti-PL natural products. In this study, a high-throughput virtual screening process for anti-PL natural products is provided. Firstly, a predictable anti-PL natural product QSAR model (R2train = 0.9444, R2test = 0.8962) were developed using the artificial intelligence drug design software MolAIcal based on genetic algorithms and their conformational relationships. 1068 highly similar (FS > 0.8) natural products were rapidly enriched based on the structure-activity similarity principle, combined with the QSAR model and the ADMET model, for rapid prediction of a total of five potentially efficient anti-PL natural products (IC50pre < 2 μM). Subsequently, molecular docking, molecular dynamics simulation, and MMGBSA free energy calculation were performed to not only reveal the interaction of candidate novel natural products with the amino acid residues of PL but also to validate the stability of these novel natural compounds bound to PL. In conclusion, this study greatly simplifies the screening and discovery of anti-PL natural products and accelerates the development of novel anti-obesity functional foods.

Inhibitory Potential of α-Amylase, α-Glucosidase, and Pancreatic Lipase by a Formulation of Five Plant Extracts: TOTUM-63

Controlling post-prandial hyperglycemia and hyperlipidemia, particularly by regulating the activity of digestive enzymes, allows managing type 2 diabetes and obesity. The aim of this study was to assess the effects of TOTUM-63, a formulation of five plant extracts (Olea europaea L., Cynara scolymus L., Chrysanthellum indicum subsp. afroamericanum B.L.Turner, Vaccinium myrtillus L., and Piper nigrum L.), on enzymes involved in carbohydrate and lipid absorption. First, in vitro inhibition assays were performed by targeting three enzymes: α-glucosidase, α-amylase, and lipase. Then, kinetic studies and binding affinity determinations by fluorescence spectrum changes and microscale thermophoresis were performed. The in vitro assays showed that TOTUM-63 inhibited all three digestive enzymes, particularly α-glucosidase (IC50 of 13.1 µg/mL). Mechanistic studies on α-glucosidase inhibition by TOTUM-63 and molecular interaction experiments indicated a mixed (full) inhibition mechanism, and higher affinity for α-glucosidase than acarbose, the reference α-glucosidase inhibitor. Lastly, in vivo data using leptin receptor-deficient (db/db) mice, a model of obesity and type 2 diabetes, indicated that TOTUM-63 might prevent the increase in fasting glycemia and glycated hemoglobin (HbA1c) levels over time, compared with the untreated group. These results show that TOTUM-63 is a promising new approach for type 2 diabetes management via α-glucosidase inhibition.