Inhibitory Activities of Cudrania tricuspidata Leaves on Pancreatic Lipase In Vitro and Lipolysis In Vivo

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.

Optimizing the Fermentation Conditions of Cudrania tricuspidata Fruit Using Bacillus amyloliquefaciens for Anti-Inflammatory Activity and GC-MS-Based Volatile Component Characteristics

The aim of this study is to optimize the performance conditions used for maximum anti-inflammatory activity and to clarify in vitroanti-inflammatory properties of fermented C. tricuspidata fruit. Based on the single-factor experiment and Box-Behnken design, the optimized fermentation conditions of C. tricuspidata fruit for maximum anti-inflammatory activity were 3.8 d fermentation period, 8.4% (v/w) inoculation concentration, and 29.2°C fermentation temperature. Under optimal conditions, anti-inflammatory activity-based nitric oxide of fermented C. tricuspidata fruit reached 93.9%. Moreover, this study provides a theoretical basis and experimental data containing β-hexosaminidase and reactive oxygen species for the medical use and industrialization of C. tricuspidata fruit fermentation. Interestingly, the results of GC-MS analysis confirmed that fermented C. tricuspidata fruits detect volatile components different from unfermented C. tricuspidata fruits. We suggested that this volatile component may have been involved in the anti-inflammatory reaction, but scientific verification of this is needed later. Therefore, an in-depth study of volatile components detected from fermented C. tricuspidata fruits will need to be conducted later.

Antioxidant and Enzyme Inhibitory Potential of Streptomyces sp. G-18 Grown in Various Media

Streptomyces are bacteria well known for producing bioactive secondary metabolites which are commonly found in diverse habitats. The biosynthesis of metabolites from Streptomyces is influenced by various factors such as the growth medium, environmental conditions, and gene regulation. This study aimed to investigate the influence of different growth media on biomass production and the antioxidant and enzyme inhibitory potential of a crude extract obtained from Streptomyces sp. G-18 isolated from high altitudinal soil of Nepal. The highest dry weight growth was observed in R2YE medium (184 mg/L), followed by R5 (144 mg/L), YEME (38 mg/L), and R5M media (30 mg/L). The crude extract showed notable antioxidant activities against free radicals. The highest alpha-amylase inhibition was observed in the R2YE medium, and worthy lipase and tyrosinase inhibition was observed in the YEME medium. However, only the R2YE medium exhibited inhibitory potential against elastase and acetylcholinesterase, while crude extracts from R5, YEME, and R5 modified did not show any such activity. Overall, our findings suggest that the production of bioactive secondary metabolites in Streptomyces sp. G-18 was significantly influenced by the growth medium. This strain may be a promising source of enzyme inhibitors with potential applications in the pharmaceutical and cosmetic industries.

Carbon Monoxide Protects Neural Stem Cells Against Iron Overload by Modulating the Crosstalk Between Nrf2 and NF-κB Signaling

Although accumulating evidences have demonstrated pro-survival effects of CO against various insults, the precise mechanism explaining how neural stem cells (NSCs) are protected by CO also remains largely unknown. Here we report CO pro-survival effect on NSCs against iron overload was comparable to that obtained with pharmacological inhibitors of reactive oxygen species (ROS). Its pro-survival effect was accompanied by the inhibition of ROS and subsequent inhibition of NF-κB which is mediated through nuclear factor erythroid 2-related factor 2 (Nrf2), in that activation of Nrf2 by CO inhibited ROS via up-regulation of NQO-1 while down-regulation of Nrf2 reversed the pro-survival effect of CO both in vitro and in vivo. CO-mediated preconditioning results in Nrf2 up-regulation and NF-κB inhibition, suggesting that these two pathways act in an inverse manner to maintain redox homeostasis. Our findings revealed CO preconditioning as a promising treatment strategy to improve efficacy of NSCs transplantation after hemorrhagic stroke.

Solid-State Fermented Okara with Aspergillus spp. Improves Lipid Metabolism and High-Fat Diet Induced Obesity

Okara is a major by-product of soymilk and tofu production. Despite retaining abundant nutrients after the process, okara is often under-utilized. In this study, solid-state fermentation (SSF) of okara was carried out using a koji starter (containing both Aspergillus oryzae and Aspergillus sojae) with the intention of releasing its untapped nutrients. Its effects on lipid metabolism in diet-induced obesity (DIO) were observed. The nutritional profile of fermented okara was elucidated using the following parameters: total phenolic content (TPC), pH, protein content, dietary fiber, amino acid content, and free sugar content. In vivo experiments were conducted using high-fat diets supplemented with unfermented okara and fermented okara over three weeks. Supplementation with fermented okara reduced body weight gain, adipose tissue weight, the serum triglyceride profile, and lipid accumulation in the liver, and altered the mRNA expression levels related to lipid metabolism; however, it did not affect pH and short-chain fatty acid (SCFA) production in this study. In conclusion, high-fat diets supplemented using okara fermented with Aspergillus spp. improved the lipid metabolism in mice, due to their high nutritional value, such as TPC, soy protein, and amino acids, and their synergistic effects without altering the gut microbiota.

Inhibition of the in vitro Activities of α-Amylase and Pancreatic Lipase by Aqueous Extracts of Amaranthus viridis, Solanum macrocarpon and Telfairia occidentalis Leaves

Inhibition of digestive enzymes such as α-amylase and pancreatic lipase (PL) is a promising therapeutic strategy for the treatment and management of chronic health conditions such as diabetes and obesity. Therefore, the aim of this work was to determine the enzyme inhibitory activity of polyphenol-rich aqueous extracts of Amaranthus viridis (AV), Solanum macrocarpon (SM) and Telfairia occidentalis (TO) leaves, which were harvested from plants produced using multiple urea fertilizer doses (0-80 kg N/ha). Fertilizer application was applied at two time points (at planting or 2 weeks after seedling emergence). Leaf extracts were obtained using aqueous extraction (1:20, leaves:water) for 4 h at 60°C followed by centrifugation and freeze-drying of the supernatant. Results showed that the extracts inhibited α-amylase, and pancreatic lipase dose-dependently with TO extracts having significantly (p < 0.05) higher inhibitory activities for both enzymes. Fluorescence intensity and circular dichroism spectra in the presence and absence of leaf extracts indicate significant changes to the enzyme protein secondary and tertiary conformations. We conclude that the leaf extracts, especially from TO are potential agents for reducing calorie intake as a preventive or treatment tool against chronic diseases such as diabetes and obesity.

Cudrania tricuspidata Combined with Lacticaseibacillus rhamnosus Modulate Gut Microbiota and Alleviate Obesity-Associated Metabolic Parameters in Obese Mice

The aim of the presented study was to investigate the synbiotic effects of L. rhamnosus 4B15 and C. tricuspidata extract administration on the gut microbiota and obesity-associated metabolic parameters in diet-induced obese mice. Thirty-one 6-week-old male C57BL/N6 mice were divided into five diet groups: normal diet (ND, n = 7) group; high-fat diet (HFD, n = 6) group; probiotic (PRO, n = 5) group; prebiotic (PRE, n = 7) group; and synbiotic (SYN, n = 6) group. After 10 weeks, the percent of fat mass, serum triglyceride, and ALT levels were significantly reduced in SYN-fed obese mice, compared with other treatments. SYN treatment also modulated the abundance of Desulfovibrio, Dorea, Adlercreutzia, Allobaculum, Coprococcus, unclassified Clostridiaceae, Lactobacillus, Helicobacter, Flexispira, Odoribacter, Ruminococcus, unclassified Erysipelotrichaceae, and unclassified Desulfovibrionaceae. These taxa showed a strong correlation with obesity-associated indices. Lastly, the SYN-supplemented diet upregulated metabolic pathways known to improve metabolic health. Further investigations are needed to understand the mechanisms driving the synbiotic effect of C. tricuspidata and L. rhamnosus 4B15.

Protective Effect of Cudrania tricuspidata Extract against High-Fat Diet Induced Nonalcoholic Fatty Liver Disease through Nrf-2/HO-1 Pathway

Nonalcoholic fatty liver disease is the most common chronic disease affecting a wide range of the world’s population and associated with obesity-induced metabolic syndrome. It is possibly emerging as a leading cause of life-threatening liver diseases for which a drug with a specific therapeutic target has not been developed yet. Previously, there have been reports on the benefits of Cudrania tricuspidata (CT) for treating obesity and diabetes via regulation of metabolic processes, such as lipogenesis, lipolysis, and inflammation. In this study, we investigated the ameliorative effect of orally administered 0.25% and 0.5% (w/w) CT mixed with high-fat diet (HFD) to C57BL/6J mice for 7 weeks. It was found that body weight, fat mass, hepatic mass, serum glucose level, and liver cholesterol levels were significantly reduced after CT treatment. In CT-treated HFD-fed mice, the mRNA expression levels of hepatic lipogenic and inflammatory cytokine-related genes were markedly reduced, whereas the expression level of epididymal lipogenic genes was increased. The mRNA expression level of beta-oxidation and Nrf-2/HO-1 genes significantly increased in CT-treated obese mice livers. We propose that CT alleviates hepatic steatosis by reducing oxidative stress and inflammation.

Effects of Maclura tricuspidata (Carr.) Bur fruits and its phytophenolics on obesity-related enzymes

The purpose of the present study was to investigate whether several phytophenolic ingredients isolated from Maclura tricuspidata (Carr.) Bur fruits inhibit the activity of obesity-related enzymes including pancreatic lipase, α-amylase, β-glucosidase, phosphodiesterase IV, alkaline phosphatase, and citrate synthase, and the compounds play as an inhibitor against the target enzymes in kinetic studies. The enzyme assays indicated that the fruit extract and its phytophenolic compounds inhibited significantly the enzymatic activity of the five target enzymes. The kinetic studies demonstrated that the inhibitory properties of p-hydroxybenzoic acid (4-HA), protocatechuic acid (PA), and isovanillic acid (IA) against pancreatic lipase, β-glucosidase, citrate synthase, or alkaline phosphatase. Our results suggested that the compounds detected from Maclura tricuspidata (Carr.) Bur fruit extract may regulate carbohydrate/lipid/energy metabolism by obesity-related enzymes' inhibition. PRACTICAL APPLICATIONS: The obesity-related metabolizing enzymes affect (in)directly the metabolites absorption on carbohydrate/lipid/energy metabolism. Accordingly, it is an important strategy to treat obesity through target pathways and enzymes which include the reduction in energy intake and consumption. In our results, Maclura tricuspidata (Carr.) Bur fruit extract and its phytophenolic compounds inhibited significantly the enzymatic activity of the five target enzymes, in particular, 4-HA, PA, and IA have each specific inhibition type on pancreatic lipase, β-glucosidase, citrate synthase, and alkaline phosphatase. Therefore, M. tricuspidata (Carr.) Bur fruit may be a strong candidate as a food material or therapeutic agent for obesity improvement.

Separation and Lipid Inhibition Effects of a Novel Decapeptide from Chlorella pyenoidose

A novel lipid inhibition peptide Leu-Leu-Val-Val-Try-Pro-Trp-Thr-Gln-Arg (PP1) (MW 1274.53 Da) was obtained from Chlorella pyenoidose using enzymatic hydrolysis, gel filtration chromatography, and LC–MS/MS. Its lipid inhibition effects indicated that the synthetic peptide PP1 exhibits a good inhibitory effect against porcine pancreatic lipase (PL) (47.95%) at 200 μg/mL, which could be attributed to its hydrogen binding into catalytic sites of PL (Ser153, Asp177, and His 264) by docking analysis. Furthermore, in 3T3-L1 cells, the synthetic PP1 remarkedly decreased the accumulation of intracellular triacylglycerol (27.9%, 600 μg/mL), which carried a similar consequence as the positive drug simvastatin (24.1%, 10 μM). Western blot revealed that PP1 inhibited the lipid accumulation and fatty acid synthesis in 3T3-L1 adipocytes in two pathways, primarily: nonalcoholic fatty liver disease (NAFLD) pathway (C/EBPα, SREBP-1c, AMPKα) and AMPK signaling pathway (SREBP-1c, PPARγ, AMPKα). In short, these results support that PP1 can be used as a potential agent against obesity.

Susceptibility of poultry associated bacterial pathogens to Momordica charantia fruits and evaluation of in vitro biological properties

The emerging incidence of antibiotic resistance trait among the bacteria populating poultry presents a devastating public health issue. On the other hand, at present, diabetes and obesity are the most serious public health issues and are increasing subsequently at alarming rate. In view of this, the present in vitro context was aimed to investigate the antibacterial activities of Momordica charantia (M. charantia) fruits extracts against poultry associated Bacillus spp. and to assess further its phytoconstituents, alpha-(α)-glucosidase activities, and anti-obesity properties. The anti-pathogenic attributes of M. charantia fruit extracts were carried out using disc diffusion assay and results showed the pronounced antibacterial trait of ethanolic extract with maximum zone of inhibition of 28.3 ± 1.2 mm against Bacillus licheniformis. The qualitative phytochemical analyses of fruit extracts illustrated the presence of diverse phytoconstituents. The α-glucosidase inhibition assay for the extracts was performed according to the α-glucosidase activity kit. The results depicted the lowest α-glucosidase activity (57.13 ± 2.3 to 18.14 ± 1.3 U/L) in the presence of ethanolic extract at varied concentrations. The anti-obesity potentialities of fruit extracts were demonstrated in terms of porcine pancreatic lipase (PPL type II) activity using p-nitro-phenyl butyrate (p-NPB) as a substrate. The ethanolic extract of M. charantia fruits was observed to exhibit maximum inhibition of pancreatic lipase ranging from 20.12 ± 2.3 to 68.34 ± 1.3% in a dose dependent manner with an IC₅₀ value of 607.6 ± 1.3 μg/mL. FTIR and GC-MS results indicated the presence of distinct compounds in the ethanol extract and major bioactive constituents were found to be Dimethyl sulfone (35.24%), 9-octadecanamide (20.52%), Pentadecanoic acid (6.64%), Lanost-9 (11)-en-18-oic acid, 23-(acetylxyl)-3-(4-bromobenzoyl) oxyl-20-hydroxyl-gamma-lactone (2.6%), and 2,2-sulfonyldiethanol (2.46%). In conclusion, M. charantia fruits could be of great concern in pharmaceutical industries due to its adequate biological properties and may also help in the management of poultry associated bacterial pathogens.

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.

Antiplatelets and profibrinolytic activity of Citrullus colocynthis in control and high-fat diet-induced obese rats: mechanisms of action

The current study aimed to investigate the effect of Citrullus colocynthis (C. colocynthis) hydro-alcoholic extract on blood haemostasis in control and high-fat diet (HFD) induced obese rats. In control rats, the extract significantly enhanced bleeding time and plasma levels of tPA and significantly decreased plasma levels PAI-1 and serum levels of thromboxane B2 leading to inhibition of platelets aggregation. In HFD induced obese rats, similar effects were seen and the extract was also able to reverse HFD induced increases in fibrinogen and VWF. Searching for the mechanism, C. colocynthis acts by (1) inhibiting of food intake, (2) inhibiting the activity of pancreatic lipase, (3) decreasing levels of TNF-α and IL-6 and (4) decreasing circulatory levels of the prothrombotic adipokine, leptin and enhanced circulatory levels of the antithrombic adipokines and adiopnectin. In conclusion, C. colocynthis has antiplatelets and profibrinolytic activity in both control and HFD induced obese rats.

Resveratrol improves high-fat diet induced fatty liver and insulin resistance by concomitantly inhibiting proteolytic cleavage of sterol regulatory element-binding proteins, free fatty acid oxidation, and intestinal triglyceride absorption

Resveratrol (RES) has the ability to ameliorate nonalcoholic fatty liver disease (NAFLD) and the mechanism remains unclear. Hence, using high-fat diet (HFD) obese rat model, we investigated the effect of a low dose of RES (20 mg/kg) on the hepatic sterol regulatory element-binding protein (SREBPs) – lipogenesis pathway, enzymes involved in β-oxidation and activity of pancreatic lipase. Four groups of rats (n = 8) of control (12% of calories as fat) and HFD (40% of calories as fat) were administered orally with either normal saline as a vehicle or RES as a concomitant treatment for 8 weeks on a daily basis. Then, various biochemical, histological, and molecular experiments were carried out. RES prevented the development and progression of NAFLD and significantly improved insulin sensitivity through (1) inhibiting the proteolytic cleavage of SREBPs-1 and SREBPs-2 without affecting their precursor mRNA or protein levels, (2) inhibiting free fatty acid β-oxidation and generation of reactive oxygen species through significant inhibition of CPT-1 and UCP-2, and (3) decreasing activity of pancreatic lipase in vivo and in vitro. In conclusion, our findings are the first in the literature to show new mechanisms of the hepatoprotective effect of RES against HFD induced NAFLD in rats.

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.

Antiobesity and Antidiabetes Effects of a Cudrania tricuspidata Hydrophilic Extract Presenting PTP1B Inhibitory Potential

Diabetes and obesity represent the major health problems and the most age-related metabolic diseases. Protein-tyrosine phosphatase 1B (PTP1B) has emerged as an important regulator of insulin signal transduction and is regarded as a pharmaceutical target for metabolic disorders. To find novel natural materials presenting therapeutic activities against diabetes and obesity, we screened various herb extracts using a chip screening allowing the determination of PTP1B inhibitory effects of the tested compounds using insulin receptor (IR) as the substrate. Cudrania tricuspidata leaves (CTe) had a strong inhibitory effect on PTP1B activity and substantially inhibited fat accumulation in 3T3-L1 cells. CTe was orally administrated to diet-induced obesity (DIO) mice once daily for 3 weeks after which changes in glucose, insulin metabolism, and fat accumulation were examined. Hepatic enzyme markers (aspartate aminotransferase, AST, and alanine aminotransferase, ALT) and total fat mass and triglyceride levels decreased in CTe-treated mice, whereas body weight and total cholesterol concentration slightly decreased. CTe increased the phosphorylation of IRS-1 and Akt in liver tissue. Furthermore, CTe treatment significantly lowered blood glucose levels and improved insulin secretion in DIO mice. Our results strongly suggest that CTe may represent a promising therapeutic substance against diabetes and obesity.

Effect of Cudrania tricuspidata and Kaempferol in Endoplasmic Reticulum Stress-Induced Inflammation and Hepatic Insulin Resistance in HepG2 Cells

In this study, we quantitated kaempferol in water extract from Cudrania tricuspidata leaves (CTL) and investigated its effects on endoplasmic reticulum (ER) stress-induced inflammation and insulin resistance in HepG2 cells. The concentration of kaempferol in the CTL was 5.07 ± 0.08 mg/g. The HepG2 cells were treated with 300 µg/mL of CTL, 500 µg/mL of CTL, 1.5 µg/mL of kaempferol or 2.5 µg/mL of kaempferol, followed immediately by stimulation with 100 nM of thapsigargin for ER stress induction for 24 h. There was a marked increase in the activation of the ER stress and inflammation response in the thapsigargin-stimulated control group. The CTL treatment interrupted the ER stress response and ER stress-induced inflammation. Kaempferol partially inhibited the ER stress response and inflammation. There was a significant increase in serine phosphorylation of insulin receptor substrate (IRS)-1 and the expression of C/EBPα and gluconeogenic genes in the thapsigargin-stimulated control group compared to the normal control. Both CTL and kaempferol suppressed serine phosphorylation of IRS-1, and the treatments did not interrupt the C/EBPα/gluconeogenic gene pathway. These results suggest that kaempferol might be the active compound of CTL and that it might protect against ER stress-induced inflammation and hyperglycemia.

Plants used in the traditional medicine of Mesoamerica (Mexico and Central America) and the Caribbean for the treatment of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Obesity is a worldwide medical concern. New ethnobotanical information regarding the antiobesity effect of medicinal plants has been obtained in the last 30 years in response to socio-demographic changes and high-fat diets became common.

AIM OF THE STUDY

This review provides a summary of medicinal plants used in Mexico, Central America and the Caribbean for the empirical treatment of obesity in terms of ethnobotany, toxicity, pharmacology, conservation status, trade and chemistry.

MATERIALS AND METHODS

Bibliographic investigation was performed by analyzing recognized books, undergraduate and postgraduate theses and peer-reviewed scientific articles, consulting worldwide accepted scientific databases from the last four decades. Medicinal plants used for the treatment of obesity were classified in two categories: (1) plants with pharmacological evidence and (2) plants without pharmacological evidence.

RESULTS

A total of 139 plant species, belonging to 61 families, native to Mexico, Central America and the Caribbean that are used for the empirical treatment of obesity were recorded. From these plants, 33 were investigated in scientific studies, and 106 plants lacked scientific investigation. Medicinal plants were experimentally studied in vitro (21 plants) and in vivo (16 plants). A total of 4 compounds isolated from medicinal plants used for the empirical treatment of obesity have been tested in vitro (2 compounds) and in vivo (4 compounds) studies. No clinical trials on obese subjects (BMI>30 kg/m(2)) have been performed using the medicinal plants cited in this review. There are no herbal-based products approved in Mexico for the treatment of obesity.

CONCLUSIONS

There are a limited number of scientific studies published on medicinal plants from Mexico, Central America and the Caribbean used for the treatment of obesity. This review highlights the need to perform pharmacological, phytochemical, toxicological and ethnobotanical studies with medicinal flora to obtain new antiobesity agents.

Medicinal Plants and Their Inhibitory Activities against Pancreatic Lipase: A Review

Obesity is recognized as a major life style disorder especially in developing countries and it is prevailing at an alarming speed in new world countries due to fast food intake, industrialization, and reduction of physical activity. Furthermore, it is associated with a vast number of chronic diseases and disabilities. To date, relatively effective drugs, from either natural or synthetic sources, are generally associated with serious side effects, often leading to cessation of clinical trials or even withdrawal from the market. In order to find new compounds which are more effective or with less adverse effects compared to orlistat, the drug that has been approved for obesity, new compounds isolated from natural products are being identified and screened for antiobesity effects, in particular, for their pancreatic lipase inhibitory effect. Pancreatic lipase inhibitory activity has been extensively used for the determination of potential efficacy of natural products as antiobesity agents. In attempts to identify natural products for overcoming obesity, more researches have been focused on the identification of newer pancreatic lipase inhibitors with less unpleasant adverse effects. In this review, we consider the potential role of plants that have been investigated for their pancreatic lipase inhibitory activity.

Cudrania tricuspidata water extract improved obesity-induced hepatic insulin resistance in db/db mice by suppressing ER stress and inflammation

BACKGROUND

Obesity can play a role in the development of hepatic insulin resistance. Although the molecular mechanism of the association between obesity and hepatic insulin resistance is unclear, it has been reported that obesity leads to hepatic endoplasmic reticulum (ER) stress and inflammation, which can induce the development of insulin resistance in several tissues.

OBJECTIVE

In this study, we investigated the associations between hepatic insulin resistance, ER, and inflammation in obesity and the effect of water extract from Cudrania tricuspidata leaves (CTL) on hepatic insulin resistance induced by ER stress and inflammation in db/db mice.

DESIGN

The mice were randomly divided into four groups: a normal control group (C57BL/6J), a control group (C57BL/6J-db/db), a CTL 100 group (C57BL/6J-db/db mice fed a dietary supplement of 100 mg/kg of CTL), and a CTL 300 group (C57BL/6J-db/db mice fed a dietary supplement of 300 mg/kg of CTL). After 8 weeks, we performed an oral glucose tolerance test and the mice were sacrificed.

RESULTS

The C57BL/6J-db/db mice developed obesity and hyperglycemia, and the ER stress response and inflammation were activated in their livers. Interestingly, there was a marked decrease in the activation of the ER stress response and insulin resistance in the livers of the C57BL/6J-db/db mice treated with CTL due to decreases in the phosphorylation of eIF2α, IRE1α, and IRS-1 serine and decreases in the mRNA expression of ATF4, c-Jun N-terminal kinase, C/EBPα, and C/EBP homologous protein. Dietary supplementation with CTL also induced a statistically significant decrease in the expression of pro-inflammatory cytokines, C-reactive protein (CRP), and NF-κB phosphorylation.

CONCLUSIONS

Overall, these results suggest that CTL can improve hepatic insulin resistance and hyperglycemia by controlling obesity-induced ER stress and inflammation in the liver and that CTL may be a useful agent in treating hyperglycemia.

Silkworm Thorn Stem Extract Targets RSK2 and Suppresses Solar UV-Induced Cyclooxygenase-2 Expression

Excessive exposure to solar UV (sUV) is associated with numerous human skin disorders, such as carcinogenesis, skin photoaging and skin inflammation. Silkworm Thorn (Cudraniatricuspidata, SW) is a plant belonging to the Moraceae family and widely present throughout Korea, China, and Japan. Most parts of the tree (including the fruit, leaf, stem, root, and bark) is consumable as a functional food or tea. In this study, we found that SW extract (SWE) inhibited the elevated expression of sUV-induced cyclooxygenase (COX)-2 levels in both HaCaT and JB6 cells. Levels of nuclear factor-κB and activator protein-1, two crucial transcription factors involved in COX-2 expression, were elevated by sUV treatment. Treatment with SWE abolished this activation. SWE also inhibited sUV-induced histone H3 phosphorylation. However, sUV-induced phosphorylation of Akt, c-Jun N-terminal kinase and p38 kinase remained unchanged in the presence of SWE. SWE inhibited RSK2 activity, and pull-down assays using SWE-Sepharose beads revealed that SWE binds directly with RSK2 in an ATP-competitive manner. These results suggest a potential for SWE to be developed as a cosmeceutical material and functional food constituent for the promotion of skin health.

Anti-obesity effects of hispidin and Alpinia zerumbet bioactives in 3T3-L1 adipocytes

Obesity and its related disorders have become leading metabolic diseases. In the present study, we used 3T3-L1 adipocytes to investigate the anti-obesity activity of hispidin and two related compounds that were isolated from Alpinia zerumbet (alpinia) rhizomes. The results showed that hispidin, dihydro-5,6-dehydrokawain (DDK), and 5,6-dehydrokawain (DK) have promising anti-obesity properties. In particular, all three compounds significantly increased intracellular cyclic adenosine monophosphate (cAMP) concentrations by 81.2% ± 0.06%, 67.0% ± 1.62%, and 56.9% ± 0.19%, respectively. Hispidin also stimulated glycerol release by 276.4% ± 0.8% and inhibited lipid accumulation by 47.8% ± 0.16%. Hispidin and DDK decreased intracellular triglyceride content by 79.5% ± 1.37% and 70.2% ± 1.4%, respectively, and all three compounds inhibited glycerol-3-phosphate dehydrogenase (GPDH) and pancreatic lipase, with hispidin and DDK being the most potent inhibitors. Finally, none of the three compounds reduced 3T3-L1 adipocyte viability. These results highlight the potential for developing hispidin and its derivatives as anti-obesity compounds.

Dohaekseunggi-tang extract inhibits obesity, hyperlipidemia, and hypertension in high-fat diet-induced obese mice

Background

Dohaekseunggi-tang (DHSGT) is a traditional plant-based medicine prescribed to promote blood circulation and to treat obesity and hypertension. The present study aimed to identify potential anti-obesity activities of DHSGT extract.

Methods

Anti-obesity, anti-hyperlipidemic, and anti-hypertensive effects of orally-administered DHSGT extract were evaluated in high-fat diet- (HFD)-induced obese mice. Serum biochemistry profiles and expression of diverse metabolic regulatory gene mRNAs in mouse visceral fat were assessed by RT-PCR. The effects of DHSGT on angiotensin-1 converting enzyme (ACE) and pancreatic lipase activities were determined using in vitro inhibition assays.

Results

Oral DHSGT treatment reduced obese HFD C57BL/6 J mouse body weight, liver and adipose tissue mass, adipocyte size, and blood pressure versus untreated HFD mice. DHSGT also decreased serum total cholesterol, LDL-cholesterol, triglyceride, glucose, and leptin concentrations, and increased HDL-cholesterol and adiponectin levels in HFD mice. Furthermore, DHSGT markedly increased mRNA expression of peroxisome proliferator activated receptor-gamma, uncoupling protein-2, and adiponectin in visceral adipose tissue of HFD mice. In vitro tests revealed that DHSGT effectively inhibited porcine pancreatic lipase and ACE activities, with IC₅₀ values of 7.58 mg/ml and 0.56 mg/ml, respectively.

Conclusions

These results validate traditional knowledge and suggest that DHSGT may be potentially useful for managing hyperlipidemia, hyperglycemia, hypertension, and obesity.

Polygonum cuspidatum inhibits pancreatic lipase activity and adipogenesis via attenuation of lipid accumulation

Background

Obesity causes metabolic disease and is a serious health problem around the world. Polygonum cuspidatum (POCU1b) has been used clinically for the treatment of constipation, gallstones, hepatitis, and inflammation in East Asian countries. The principal aim of this study was to investigate for the first time whether the extract of Polygonum cuspidatum (POCU) biologically affects adipogenesis in 3 T3-L1 preadipocytes.

Methods

Fractions (n-hexan, ethyl acetate, n-butanol, and water) of POCU ethanol extract were evaluated in vitro for their inhibitory activities on pancreatic lipase. Of the fractions, the n-butanol of POCU ethanol extract (POCU1b) was examined anti-obesity activity in 3 T3-L1 preadipocytes. To examine the inhibitory effect of POCU1b on adipogenesis, 3 T3-L1 preadipocytes were treated every the other day with POCU1b at various concentrations (0 ~ 25 μg/mL) for twelve days. Oil-red O staining and triglyceride content assay were performed to determine the lipid accumulation. The expression of mRNA and proteins associated lipid accumulation was measured using RT-PCR and Western blotting analysis. We also examined the effect of POCU1b on level of phosphorylated AMP-activated protein kinase (pAMPK) in 3 T3-L1 preadipocytes with POCU1b at various concentrations during adipocyte differentiation.

Results

POCU1b exhibited the most pronounced inhibitory effects on pancreatic lipase activity. We found that POCU1b inhibited adipocyte differentiation in 3 T3-L1 preadipocytes in a dose-dependent manner, as evidenced by the reduced formation of lipid droplets and decreased glycerol-3-phosphate dehydrogenase (GPDH) activity. We also showed that the expression levels of adipocyte differentiation-related protein (ADRP) and perilipin (a protein that coats lipid droplets in adipocytes) were both reduced after POCU1b treatment. Peroxisome proliferator-activated receptor-gamma (PPAR-γ) and CCAAT/enhancer-binding protein-alpha (C/EBP-α) proteins, both major adipogenic transcription factors, were markedly reduced by POCU1b. Moreover, ADRP, perilipin, C/EBP-α, and PPAR-γ mRNA levels were also reduced by POCU1b. Levels of phosphorylated AMP-activated protein kinase (pAMPK) were elevated after POCU1b treatment (5, 10, and 25) in a dose-dependent manner.

Conclusions

Taken together, these results suggest that the anti-obesity effects of POCU1b involve the inhibition of pancreatic lipase activity and adipogenesis via the down-regulation of lipid accumulation.