A Trypsin Inhibitor from Tamarind Reduces Food Intake and Improves Inflammatory Status in Rats with Metabolic Syndrome Regardless of Weight Loss

Effect of different physical pre-treatments on physicochemical and techno-functional properties, and on the antinutritional factors of lentils (Lens culinaris spp)

Lentils have a valuable physicochemical profile, which can be affected by the presence of antinutrients that may impair the benefits arising from their consumption. Different treatments can be used to reduce these undesirable compounds, although they can also affect the general composition and behaviour of the lentils. Thus, the effect of different processing methods on the physicochemical and techno-functional properties, as well as on the antinutritional factors of different lentil varieties was studied. Phytic acid was eliminated during germination, while tannins and trypsin inhibitors are mostly affected by cooking. Functional properties were also altered by processing, these being dependent on the concentration of different nutrients in lentils. All the studied treatments affected the physicochemical profile of lentils and their functional properties. Cooking and germination appear to be the most effective in reducing antinutritional factors and improving the physicochemical profile of the lentils, meeting the current nutritional demands of today's society.

Encapsulated Peptides and Proteins with an Effect on Satiety

The world scenario has undergone a nutritional transition in which some countries have left the reality of malnutrition and now face an epidemic of excess body weight. Researchers have been looking for strategies to reverse this situation. Peptides and proteins stand out as promising molecules with anti-obesity action. However, oral administration and passage through the gastrointestinal tract face numerous physiological barriers that impair their bioactive function. Encapsulation aims to protect the active substance and modify the action, one possibility of potentiating anti-obesity activity. Research with encapsulated peptides and proteins has demonstrated improved stability, delivery, controlled release, and increased bioactivity. However, it is necessary to explore how proteins and peptides affect weight loss and satiety, can impact the nutritional status of obesity, and how encapsulation can enhance the bioactive effects of these molecules. This integrative review aimed to discuss how the encapsulation of protein molecules impacts the nutritional status of obesity. From the studies selected following pre-established criteria, it was possible to infer that the encapsulation of proteins and peptides can contribute to greater efficiency in reducing weight gain, changes in adipose tissue function, and lower hormone levels that modulate appetite and body weight in animals with obesity.

Prospecting in silico antibacterial activity of a peptide from trypsin inhibitor isolated from tamarind seed

Bacterial infections have become a global concern, stimulating the growing demand for natural and biologically safe therapeutic agents with antibacterial action. This study was evaluated the genotoxicity of the trypsin inhibitor isolated from tamarind seeds (TTI) and the antibacterial effect of TTI theoric model, number 56, and conformation number 287 (TTIp 56/287) and derived peptides in silico. TTI (0.3 and 0.6 mg.mL⁻¹) did not cause genotoxicity in cells (p > 0.05). In silico, a greater interaction of TTIp 56/287 with the Gram-positive membrane (GP) was observed, with an interaction potential energy (IPE) of −1094.97 kcal.mol⁻¹. In the TTIp 56/287-GP interaction, the Arginine, Threonine (Thr), and Lysine residues presented lower IPE. In molecular dynamics (MD), Peptidotrychyme59 (TVSQTPIDIPIGLPVR) showed an IPE of −518.08 kcal.mol⁻¹ with the membrane of GP bacteria, and the Thr and Arginine residues showed the greater IPE. The results highlight new perspectives on TTI and its derived peptides antibacterial activity.

Nanoparticles Containing Tamarind Isolate Protein Potentiate the Satiety without Promoting the Anti-Inflammatory Effect in a Preclinical Model of Diet-Induced Obesity

The study aimed to evaluate the nanoparticles (ECW) containing tamarind trypsin inhibitor (TTI) concerning the storage effect under different conditions on antitrypsin activity and the bioactive potential in a preclinical model. ECW was exposed to different pH and temperatures to evaluate the interaction between TTI and its encapsulating agents, monitored by antitrypsin activity. Wistar rats (n = 25) with obesity induced by diet were divided into groups: untreated; treatment with nutritionally adequate diet; treatment with nutritionally adequate diet and ECW/12.5 mg/kg; treatment with ECW/12.5 mg/kg; and treatment with TTI/25 mg/kg. The groups were evaluated over ten days with regards to satiety, zoometric, biochemical, and inflammatory parameters, using ten times less TTI (2.5 mg/kg) contained in ECW. TTI was protected and encapsulated in ECW without showing residual inhibitory activity. Only at gastric pH did ECW show antitrypsin activity. At different temperatures, it showed high antitrypsin activity, similar to TTI. The animals treated with ECW had significantly reduced body weight variation (p < 0.05), and only TTI treatment reduced the inflammatory parameters significantly (p < 0.05). The study showed that by using lower concentrations of TTI in ECW it was possible to perceive promising effects with perspectives of use in functional products for managing obesity and its complications.

Anti-Inflammatory Protein Isolated from Tamarind Promotes Better Histological Aspects in the Intestine Regardless of the Improvement of Intestinal Permeability in a Preclinical Study of Diet-Induced Obesity

Obesity is associated with metabolic and physiological effects in the gut. In this study, we evaluated the anti-inflammatory effect of trypsin inhibitor isolated from tamarind seeds (TTI) in vitro (interaction with lipopolysaccharide (LPS) and inhibitory activity against human neutrophil elastase (HNE)), and using intestinal co-cultures of Caco-2:HT29-MTX cell lines inflamed with TNF-α (50 ng/mL) and a Wistar rat model of diet-induced obesity (n = 15). TTI was administered to animals by gavage (10 days), and the treated group (25 mg/kg/day) was compared to animals without treatment or treated with a nutritionally adequate diet. In the in vitro study, it showed inhibitory activity against HNE (93%). In co-cultures, there was no protection or recovery of the integrity of inflamed cell monolayers treated with TTI (1.0 mg/mL). In animals, TTI led to lower plasma concentrations of TNF-α and IL-6, total leukocytes, fasting glucose, and LDL-c (p < 0.05). The intestines demonstrated a lower degree of chronic enteritis, greater preservation of the submucosa, and greater intestinal wall thickness than the other groups (p = 0.042). Therefore, the better appearance of the intestine not reflected in the intestinal permeability added to the in vitro activity against HNE point to possibilities for new studies and applications related to this activity.

An Insulin Receptor-Binding Multifunctional Protein from Tamarindus indica L. Presents a Hypoglycemic Effect in a Diet-Induced Type 2 Diabetes-Preclinical Study

The objectives of this study were to evaluate the hypoglycemic effect of the trypsin inhibitor isolated from tamarind seeds (TTI) in an experimental model of T2DM and the in silico interaction between the conformational models of TTI 56/287 and the insulin receptor (IR). After inducing T2DM, 15 male Wistar rats were randomly allocated in three groups (n = 5): 1—T2DM group without treatment; 2—T2DM group treated with adequate diet; and 3—T2DM treated with TTI (25 mg/kg), for 10 days. Insulinemia and fasting glucose were analyzed, and the HOMA-IR and HOMA-β were calculated. The group of animals treated with TTI presented both lower fasting glucose concentrations (p = 0.0031) and lower HOMA-IR indexes (p = 0.0432), along with higher HOMA-β indexes (p = 0.0052), than the animals in the other groups. The in silico analyses showed that there was an interaction between TTIp 56/287 and IR with interaction potential energy (IPE) of −1591.54 kJ mol⁻¹ (±234.90), being lower than that presented by insulin and IR: −894.98 kJ mol⁻¹ (±32.16). In addition, the presence of amino acids, type of binding and place of interaction other than insulin were identified. This study revealed the hypoglycemic effect of a bioactive molecule of protein origin from Tamarind seeds in a preclinical model of T2DM. Furthermore, the in silico analysis allowed the prediction of its binding in the IR, raising a new perspective for explaining TTI’s action on the glycemic response.

Structural insights and molecular dynamics into the inhibitory mechanism of a Kunitz-type trypsin inhibitor from Tamarindus indica L

Trypsin inhibitors from tamarind seed have been studied in vitro and in preclinical studies for the treatment of obesity, its complications and associated comorbidities. It is still necessary to fully understand the structure and behaviour of these molecules. We purifed this inhibitor, sequenced de novo by MALDI-TOF/TOF, performed its homology modelling, and assessed the interaction with the trypsin enzyme through molecular dynamics (MD) simulation under physiological conditions. We identified additional 75 amino acid residues, reaching approximately 72% of total coverage. The four best conformations of the best homology modelling were submitted to the MD. The conformation n°287 was selected considering the RMSD analysis and interaction energy (-301.0128 kcal.mol-1). Residues Ile (54), Pro (57), Arg (59), Arg (63), and Glu (78) of pTTI presented the highest interactions with trypsin, and arginine residues were mainly involved in its binding mechanism. The results favour bioprospecting of this protein for pharmaceutical health applications.

Beneficial Effects of Tamarind Trypsin Inhibitor in Chitosan-Whey Protein Nanoparticles on Hepatic Injury Induced High Glycemic Index Diet: A Preclinical Study

Several studies have sought new therapies for obesity and liver diseases. This study investigated the effect of the trypsin inhibitor isolated from tamarind seeds (TTI), nanoencapsulated in chitosan and whey protein isolate (ECW), on the liver health status of the Wistar rats fed with a high glycemic index (HGLI) diet. The nanoformulations without TTI (CW) and ECW were obtained by nanoprecipitation technique, physically and chemically characterized, and then administered to the animals. The adult male Wistar rats (n = 20) were allocated to four groups: HGLI diet + water; standard diet + water; HGLI diet + ECW (12.5 mg/kg); and HGLI diet + CW (10.0 mg/kg), 1 mL per gagave, for ten days. They were evaluated using biochemical and hematological parameters, Fibrosis-4 Index for Liver Fibrosis (FIB-4), AST to Platelet Ratio Index (APRI) scores, and liver morphology. Both nanoparticles presented spherical shape, smooth surface, and nanometric size [120.7 nm (ECW) and 136.4 nm (CW)]. In animals, ECW reduced (p < 0.05) blood glucose (17%), glutamic oxalacetic transaminase (39%), and alkaline phosphatase (24%). Besides, ECW reduced (p < 0.05) APRI and FIB-4 scores and presented a better aspect of hepatic morphology. ECW promoted benefits over a liver injury caused by the HGLI diet.

What are the digestion and absorption models used to reproduce gastrointestinal protein processes?: A protocol for systematic review

BACKGROUND

Animal, cell, and in vitro studies have been applied to simulate the human gastrointestinal tract (GIT) and evaluate the behavior of biomolecules. Understanding the peptides and/or proteins stability when exposed to these physiological conditions of the GIT can assist in the application of these molecules in the treatment of diseases such as obesity. This study describes a protocol of systematic reviews to analyze the methodologies that mimic the digestive and absorptive processes of peptides and/or proteins.

METHODS

The protocol follows the guidelines described by Preferred Reporting Items for Systematic Reviews and Meta-Analyzes Protocols (PRISMA-P). The search strategies will be applied in the electronic databases PubMed, ScienceDirect, Scopus, Web of Science, Evidence portal, Virtual Health Library, and EMBASE. The intervention group will be formed by in vivo, in cells, and in vitro (gastrointestinal simulating fluids) studies of digestion and absorption of peptides and/or proteins presenting a schedule, duration, frequency, dosages administered, concentration, and temperature, and the control group consisting in studies without peptides and/or proteins. The selection of studies, data extraction, and assessment of the risk of bias will be carried out independently by 2 reviewers. For animal studies, the risk of bias will be assessed by the instrument of the Systematic Review Center for Experimentation with Laboratory Animals (SYRCLE) and the Office of Health Assessment and Translation (OHAT) tool will be used to assess the risk of bias in cell studies.

RESULTS

This protocol contemplates the development of 2 systematic reviews and will assist the scientific community in identifying methods related to the digestive and absorptive processes of peptides and/or proteins.

CONCLUSION

Both systematic reviews resulting from this protocol will provide subsidies for the construction of research related to the clinical application of bioactive peptides and/or proteins. In this context, they will make it possible to understand the gastrointestinal processes during administering these molecules, as the gastrointestinal environment can affect its functionality. Therefore, validating the effectiveness of these protocols is important, as it mimics in vitro biological conditions, reducing the use of animals, being consistent with the reduction, refine and replace program.

Tamarind (Tamarindus indica L.) Seed a Candidate Protein Source with Potential for Combating SARS-CoV-2 Infection in Obesity

Introduction:

Obesity and coronavirus disease (COVID)-19 are overlapping pandemics, and one might worsen the other.

Methods:

This narrative review discusses one of the primary mechanisms to initiate acute respiratory distress syndrome, uncontrolled systemic inflammation in COVID-19, and presents a potential candidate for adjuvant treatment. Blocking the S protein binding to angiotensin-converting enzyme 2 (ACE-2) and the 3C-like protease (3CL ^pro) is an effective strategy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Results:

Host proteases such as FURIN, trypsin, and transmembrane serine protease 2 (TMPRSS) act in S protein activation. Tamarind trypsin inhibitor (TTI) shows several beneficial effects on the reduction of inflammatory markers (tumor necrosis factor α [TNF-α], leptin) and biochemical parameters (fasting glycemia, triglycerides, and very low-density lipoprotein [VLDL]), in addition to improving pancreatic function and mucosal integrity in an obesity model. TTI may inhibit the action of proteases that collaborate with SARS-CoV-2 infection and the neutrophil activity characteristic of lung injury promoted by the virus.

Conclusion:

Thus, TTI may contribute to combating two severe overlapping problems with high cost and social complex implications, obesity and COVID-19.

A Review on the Role of Food-Derived Bioactive Molecules and the Microbiota-Gut-Brain Axis in Satiety Regulation

Obesity is a chronic disease resulting from an imbalance between energy intake and expenditure. The growing relevance of this metabolic disease lies in its association with other comorbidities. Obesity is a multifaceted disease where intestinal hormones such as cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY), produced by enteroendocrine cells (EECs), have a pivotal role as signaling systems. Receptors for these hormones have been identified in the gut and different brain regions, highlighting the interconnection between gut and brain in satiation mechanisms. The intestinal microbiota (IM), directly interacting with EECs, can be modulated by the diet by providing specific nutrients that induce environmental changes in the gut ecosystem. Therefore, macronutrients may trigger the microbiota-gut-brain axis (MGBA) through mechanisms including specific nutrient-sensing receptors in EECs, inducing the secretion of specific hormones that lead to decreased appetite or increased energy expenditure. Designing drugs/functional foods based in bioactive compounds exploiting these nutrient-sensing mechanisms may offer an alternative treatment for obesity and/or associated metabolic diseases. Organ-on-a-chip technology represents a suitable approach to model multi-organ communication that can provide a robust platform for studying the potential of these compounds as modulators of the MGBA.

Diagnostic Criteria for Metabolic Syndrome in Diet-Induced Rodent Models: A Systematic Review

BACKGROUND

Thousands of publications in recent years have addressed the induction of metabolic syndrome (MetS) in rodents. However, the criteria and the reference values for diagnosing this disease have not been defined.

OBJECTIVE

Our main objective was to carry out a systematic review to gather evidence about the criteria for biochemical and anthropometric parameters in which scientific studies have relied on to report that rats developed MetS from a previous dietary manipulation.

METHODS

We compiled characteristics and findings of diet-induced MetS with high-fat, high-carbohydrate, high-fat/high-carbohydrates, and cafeteria diet from PubMed and Science Direct databases published in the last 5 years.

RESULTS

The results on the principal determinants for the syndrome, published in the reviewed articles, were chosen to propose reference values in the rat models of food induction.

CONCLUSION

The values obtained will serve as reference cut-of points in the development of the disease; in addition, the compilation of data will be useful in planning and executing research protocols in animal models.

Tamarind Multifunctional Protein: Safety and Anti-Inflammatory Potential in Intestinal Mucosa and Adipose Tissue in a Preclinical Model of Diet-Induced Obesity

INTRODUCTION

Obesity has emerged as one of the main public health problems. This condition triggers a series of hormonal and metabolic changes related to a low-grade chronic inflammatory condition. The trypsin inhibitor purified from tamarind (TTIp) seeds is a promising anti-inflammatory molecule, but its safety needs to be evaluated. This study aimed to evaluate TTIp bioactive dose effects on organs involved in its metabolism (liver and pancreas) and affected tissues (small intestine and perirenal adipose tissue) in an obesity model.

METHODS

Three groups of adult male Wistar rats were used (n = 5). Two of these groups had diet-induced obesity, and a third group was eutrophic. TTIp was administered by gavage in one of the obese groups for 10 days, while the remaining groups received a vehicle. The chromatographic profile and the inhibition assay corroded the purification of the inhibitor. Physical and behavioral changes, liver enzymes, and stereological and histopathological analyses of tissues were evaluated.

RESULTS

TTIp did not cause visible signs of toxicity, nor caused changes in liver enzymes, the liver, and pancreatic tissues. TTIp did not cause changes in the intestinal mucosa, showing improvement in the villi's histopathological characteristics compared to the group of animals with obesity without treatment with TTIp (p = 0.004). The analysis of perirenal adipose tissue showed that the average sectional area of animals with obesity that received TTIp did not differ from the control. There was a difference between the high glycemic load diet group and the group treated with the inhibitor (351.8 ± 55.5) (p = 0.016). In addition, the group that received TTIp had no inflammatory infiltrates.

CONCLUSION

Based on histological and stereological analysis, the use of TTIp is potentially safe and anti-inflammatory in the evaluated obesity model and can be investigated as a possible adjuvant in obesity therapy.

Insulin-Like Proteins in Plant Sources: A Systematic Review

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia. Proteins in plant sources that enable the maintenance of the glycemic profile may be of interest in the context of T2DM. However, their mechanisms of action are unclear, unlike other bioactive compounds. This systematic review identified and described the mechanisms of action of isolated and purified proteins and peptides extracted from vegetables on the reduction of blood glucose in T2DM in experimental studies. The research was done in PubMed, ScienceDirect, Scopus, Web of Science, Embase and Virtual Health Library (VHL) databases in March 2019. The initial search retrieved 916 articles, and, after reading the title, abstract and keywords, 24 articles were eligible for full reading. Then, five articles were eligible to build this systematic review. The evaluation of the evidence and the strength of the recommendations of the studies was evaluated with the SYstematic Review Center for Laboratory animal Experimentation - SYRCLE. Studies with proteins or peptides extracted from soybean (Glycine max), corn (Zea mays), peas (Pisum sativum), costus (Costus igneus) and ginseng (Panax ginseng) were found, and all of them decreased glycemia but not by the same mechanisms. The mechanism of action of proteins extracted from Glycine max, Pisum sativum, Costus igneus were similar, acting in the insulin-mediated pathways. The peptide derived from Zea mays increased GLP-1 expression, and the peptide from Panax ginseng reduced NF-kB signaling, both resulting in stimulating the release of insulin. Therefore, bioactive proteins and peptides of plant sources act through biochemical pathways, in the modulation of insulin resistance and the hyperglycemic state. These compounds are promising in scientific research on T2DM, because there is a probable similarity of these proteins with insulin, which enables them to act as insulin-like molecules.

Trypsin inhibitors: promising candidate satietogenic proteins as complementary treatment for obesity and metabolic disorders?

The increase in non-communicable chronic diseases has aroused interest in the research of adjuvants to the classic forms of treatments. Obesity and metabolic syndrome are the main targets of confrontation because they relate directly to other chronic diseases. In this context, trypsin inhibitors, molecules with wide heterologous application, appear as possibilities in the treatment of overweight and obesity due to the action on satiety related mechanisms, mainly in the modulation of satiety hormones, such as cholecystokinin. In addition, trypsin inhibitors have the ability to also act on some biochemical parameters related to these diseases, thus, emerging as potential candidates and promising molecules in the treatment of the obesity and metabolic syndrome. Thus, the present article proposes to approach, through a systematic literature review, the advantages, disadvantages and viabilities for the use of trypsin inhibitors directed to the treatment of overweight and obesity.

Tamarind Trypsin Inhibitor in Chitosan-Whey Protein Nanoparticles Reduces Fasting Blood Glucose Levels without Compromising Insulinemia: A Preclinical Study

In vivo studies show the benefits of the trypsin inhibitor isolated from tamarind (Tamarindusindica L.) (TTI) seeds in satiety and obesity. In the present study, TTI nanoencapsulation (ECW) was performed to potentialize the effect of TTI and allow a controlled release in the stomach. The impact on glycemia, insulin, and lipid profile was evaluated in Wistar rats overfed with a high glycemic index diet (HGLI). Characterization of the nanoparticles and in vitro stability in simulated gastrointestinal conditions, monitored by antitrypsin activity and HPLC, was performed. ECW and empty nanoparticles (CW) were administered by gavage, using 12.5 and 10.0 mg/kg, respectively. Both nanoformulations presented a spherical shape and smooth surface, with an average diameter of 117.4 nm (24.1) for ECW and 123.9 nm (11.3) for CW. ECW maintained the antitrypsin activity (95.5%) in the gastric phase, while TTI was completely hydrolyzed. In Wistar rats, the nanoformulations significantly reduced glycemia and HOMA IR, and ECW increased HDL-c compared to CW (p < 0.05).Pancreas histopathology of animals treated with ECW suggested an onset of tissue repair. Thenanoencapsulation provided TTI protection, gradual release in the desired condition, and improvement of biochemical parameters related to carbohydrate metabolism disorders,without compromising insulinemia.

Serine protease inhibition and modulatory-antibiotic activity of the proteic extract and fractions from Amburana cearensis

This study investigated the inhibitory activity of serine protease, as well as antibacterial and antibiotic modifying activities of the crude extract and fractions of A. cearensis seeds. Microdilution assay was used to evaluate the antibacterial activity and the antibiotic resistance-modulating effects of samples against multiresistant bacteria Staphylococcus aureus (SA10) and Escherichia coli (EC06). In the inhibition test for serine protease, all the samples showed inhibition of enzymatic activity. Crude extract and fractions of A. cearensis seeds showed a Minimum Inhibitory Concentration ≥1024 μg/mL for all microorganisms tested. However, the samples acted as resistance modifying agent, presenting synergism when associated with gentamicin, norfloxacin and penicillin. The present study provides data indicating a possible use of the seeds extract of A. cearensis in association with antibiotics in the fight against bacterial infections.

Mechanism of the action of bioactive proteins of vegetables in diabetes mellitus type 2: Systematic review protocol

BACKGROUND

Diabetes mellitus type 2 (DM2) is a chronic disease of significant prevalence causing hyperglycemia and several comorbidities. Evidences highlight the performance of non - protein bioactive compounds found in vegetables in the control of hyperglycemia. This study describes a protocol of a systematic review, which analyzes the action of proteins and bioactive peptides of plants in DM2.

METHODS

The Preferred Reporting Items guide this protocol for Systematic Reviews and Meta-Analyzes Protocols (PRISMA-P) was used. The databases that will be used for searching will be PubMed, ScienceDirect, Scopus, Web of Science, EMBASE, and Virtual Health Library, Brazil (VHL). Studies that use bioactive proteins and peptides of vegetal origin in DM2 will be included in the systematic review. The studies will be identified using clinical parameters and the effect on insulin resistance. The characteristics of the studies as control groups, test substance, dosage, intervention time, and the main results will be described. Selection of studies, data extraction, and methodological quality assessment will be performed independently by two experienced reviewers.

RESULTS

This protocol will be the basis for a systematic review identifying the mechanism of action of plant proteins and peptides in type 2 diabetes mellitus.

CONCLUSION

Systematic reviews from this protocol will provide support for the construction of researches that analyze the effect of plant bioactive proteins and peptides on the control of hyperglycemia and how these molecules act in the control of DM2.

PROSPERO REGISTRATION NUMBER

CRD42019110956.

Contribution of momilactones A and B to diabetes inhibitory potential of rice bran: Evidence from in vitro assays

This study was the first to detect the presence of the two compounds momilactone A (MA) and momilactone B (MB) in rice bran using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). By in vitro assays, both MA and MB exhibited potent inhibitory activities on pancreatic α-amylase and α-glucosidase which were significantly higher than γ-oryzanol, a well-known diabetes inhibitor. Remarkably, MA and MB indicated an effective inhibition on trypsin with the IC50 values of 921.55 and 884.03 µg/mL, respectively. By high-performance liquid chromatography (HPLC), quantities of MA (6.65 µg/g dry weight) and MB (6.24 µg/g dry weight) in rice bran were determined. Findings of this study revealed the α-amylase, α-glucosidase and trypsin inhibitors MA and MB contributed an active role to the diabetes inhibitory potential of rice bran.

Anti-TNF-α Agent Tamarind Kunitz Trypsin Inhibitor Improves Lipid Profile of Wistar Rats Presenting Dyslipidemia and Diet-induced Obesity Regardless of PPAR-γ Induction

: The increasing prevalence of obesity and, consequently, chronic inflammation and its complications has increased the search for new treatment methods. The effect of the purified tamarind seed trypsin inhibitor (TTIp) on metabolic alterations in Wistar rats with obesity and dyslipidemia was evaluated. Three groups of animals with obesity and dyslipidemia were formed, consuming a high glycemic index and glycemic load (HGLI) diet, for 10 days: Obese/HGLI diet; Obese/standard diet; Obese/HGLI diet + TTIp (730 μg/kg); and one eutrophic group of animals was fed a standard diet. Rats were evaluated daily for food intake and weight gain. On the 11th day, animals were anesthetized and sacrificed for blood and visceral adipose tissue collection. TTIp treated animals presented significantly lower food intake than the untreated group (p = 0.0065), TG (76.20 ± 18.73 mg/dL) and VLDL-C (15.24 ± 3.75 mg/dL). Plasma concentrations and TNF-α mRNA expression in visceral adipose tissue also decreased in obese animals treated with TTIp (p < 0.05 and p = 0.025, respectively) with a negative immunostaining. We conclude that TTIp presented anti-TNF-α activity and an improved lipid profile of Wistar rats with dyslipidemia and obesity induced by a high glycemic index and load diet regardless of PPAR-γ induction.

BG-4, a novel bioactive peptide from momordica charantia, inhibits lipopolysaccharide-induced inflammation in THP-1 human macrophages

BACKGROUND

Bitter melon (Momordica charantia) is a commonly used food crop for management of a variety of diseases most notably for control of diabetes, a disease associated with aberrant inflammation.

PURPOSE

To evaluate the anti-inflammatory property of BG-4, a novel bioactive peptide isolated from the seed of bitter melon.

METHODS

Differentiated THP-1 human macrophages were pre-treated with BG-4 and stimulated with lipopolysaccharide. Pro-inflammatory cytokines IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay. The mechanism of action involving activation of NF-κB and phosphorylation of ERK and STAT3 was measured by western blot and immunofluorescence. The production of intracellular reactive oxygen species was evaluated by fluorescence microscopy and fluorescence spectrophotometry.

RESULTS

BG-4 dose dependently reduce the production of pro-inflammatory cytokines IL-6 and TNF-α. The ability of BG-4 to reduce production of cytokines are associated with reduced phosphorylation of ERK and STAT3 accompanied by reduced nuclear translocation of p65 NF-κB subunit. The mechanism of action is reduction of LPS-induced production of intracellular reactive oxygen species.

CONCLUSION

Our results demonstrated the ability of BG-4, a novel peptide from the seed of bitter melon, to exert anti-inflammatory action. This could explain the traditional use of bitter melon against diseases associated with aberrant and uncontrolled inflammation.

Biochemical characterisation of a Kunitz-type inhibitor from Tamarindus indica L. seeds and its efficacy in reducing plasma leptin in an experimental model of obesity

A trypsin inhibitor isolated from tamarind seed (TTI) has satietogenic effects in animals, increasing the cholecystokinin (CCK) in eutrophy and reducing leptin in obesity. We purified TTI (pTTI), characterised, and observed its effect upon CCK and leptin in obese Wistar rats. By HPLC, and after amplification of resolution, two protein fractions were observed: Fr1 and Fr2, with average mass of [M + 14H]⁺ = 19,594,690 Da and [M + 13H]⁺ = 19,578,266 Da, respectively. The protein fractions showed 54 and 53 amino acid residues with the same sequence. pTTI presented resistance to temperature and pH variations; IC₅₀ was 2.7 × 10⁻¹⁰mol.L⁻¹ and Ki was 2.9 × 10⁻¹¹mol.L⁻¹. The 2-DE revealed spots with isoelectric points between pH 5 and 6, and one near pH 8. pTTI action on leptin decrease was confirmed. We conclude that pTTI is a Kunitz trypsin inhibitor with possible biotechnological health-related application.

Satietogenic Protein from Tamarind Seeds Decreases Food Intake, Leptin Plasma and CCK-1r Gene Expression in Obese Wistar Rats

OBJECTIVE

This study evaluated the effect of a protein, the isolated Trypsin Inhibitor (TTI) from Tamarindus indica L. seed, as a CCK secretagogue and its action upon food intake and leptin in obese Wistar rats.

METHODS

Three groups of obese rats were fed 10 days one of the following diets: Standard diet (Labina®) + water; High Glycemic Index and Load (HGLI) diet + water or HGLI diet + TTI. Lean animals were fed the standard diet for the 10 days. Food intake, zoometric measurements, plasma CCK, plasma leptin, relative mRNA expression of intestinal CCK-related genes, and expression of the ob gene in subcutaneous adipose tissue were assessed.

RESULTS

TTI decreased food intake but did not increase plasma CCK in obese animals. On the other hand, TTI treatment decreased CCK-1R gene expression in obese animals compared with the obese group with no treatment (p = 0.027). Obese animals treated with TTI presented lower plasma leptin than the non-treated obese animals.

CONCLUSION

We suggest that TTI by decreasing plasma leptin may improve CCK action, regardless of its increase in plasma from obese rats, since food intake was lowest.