Capsinoids and related food ingredients activating brown fat thermogenesis and reducing body fat in humans

The gut-liver axis in fatty liver disease: role played by natural products

Fatty liver disease, a condition characterized by fatty degeneration of the liver, mainly classified as non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD), has become a leading cause of cirrhosis, liver cancer and death. The gut-liver axis is the bidirectional relationship between the gut and its microbiota and its liver. The liver can communicate with the gut through the bile ducts, while the portal vein transports the products of the gut flora to the liver. The intestinal flora and its metabolites directly and indirectly regulate hepatic gene expression, leading to an imbalance in the gut-liver axis and thus contributing to the development of liver disease. Utilizing natural products for the prevention and treatment of various metabolic diseases is a prevalent practice, and it is anticipated to represent the forthcoming trend in the development of drugs for combating NAFLD/ALD. This paper discusses the mechanism of the enterohepatic axis in fatty liver, summarizes the important role of plant metabolites in natural products in fatty liver treatment by regulating the enterohepatic axis, and provides a theoretical basis for the subsequent development of new drugs and clinical research.

Limb, sex, but not acute dietary capsaicin, modulate the near-infrared spectroscopy-vascular occlusion test estimate of muscle metabolism

The downward slope during the near-infrared spectroscopy (NIRS)-vascular occlusion test (NIRS-VOT) is purported as a simplified estimate of metabolism. Whether or not the NIRS-VOT exhibits sex- or limb-specificity or may be acutely altered remains to be elucidated. Thus, we investigated if there is limb- or sex specificity in tissue desaturation rates (DeO2) during a NIRS-VOT, and if acute dietary capsaicin may alter this estimate of muscle metabolism. Young healthy men (n = 25, 21 ± 4 years) and women (n = 20, 20 ± 1 years) ingested either placebo or capsaicin, in a counterbalanced, single-blind, crossover design after which a simplified NIRS-VOT was conducted to determine the DeO2 (%/s), as an estimate of oxidative muscle metabolism, in both the forearm (flexors) and thigh (vastus lateralis). There was a significant limb effect with the quadriceps having a greater DeO2 than the forearm (-2.31 ± 1.34 vs. -1.78 ± 1.22%/s, p = 0.007, ηp 2 = 0.19). There was a significant effect of sex on DeO2 (p = 0.005, ηp 2 = 0.203) with men exhibiting a lesser DeO2 than women (-1.73 ± 1.03 vs. -2.36 ± 1.32%/s, respectively). This manifested in significant interactions of limb*capsaicin (p = 0.001, ηp 2 = 0.26) as well as limb*capsaicin*sex on DeO2 (p = 0.013, ηp 2 = 0.16) being observed. Capsaicin does not clearly alter O2-dependent muscle metabolism, but there was apparent limb and sex specificity, interacting with capsaicin in this NIRS-derived assessment.

Hepatoprotection of capsaicin in alcoholic and non-alcoholic fatty liver diseases

Alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) are common causes of chronic liver disease that share the range of steatosis, steatohepatitis, fibrosis, cirrhosis, and finally, hepatocellular carcinoma. They are identified by the dysregulation of disease-specific signalling pathways and unique microRNAs. Capsaicin is an active ingredient of chilli pepper that acts as an agonist of transient receptor potential vanilloid subfamily 1. It seems that the protective role of capsaicin against NAFLD and ALD is linked to its anti-steatotic, antioxidant, anti-inflammatory, and anti-fibrotic effects. Capsaicin-induced inhibiting metabolic syndrome and gut dysbiosis and increasing bile acids production are also involved in its anti-NAFLD role. This review summarises the different molecular mechanisms underlying the protective role of capsaicin against NAFLD and ALD. More experimental studies are needed to clarify the effects of capsaicin on the expression of genes involved in hepatic lipid metabolism and hepatocytes apoptosis in NAFLD and ALD.

Natural compounds as obesity pharmacotherapies

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.

The effects of capsaicin intake on weight loss among overweight and obese subjects: a systematic review and meta-analysis of randomised controlled trials

Animal studies have shown that capsaicin plays a positive role in weight management. However, the results in human research are controversial. Therefore, the present systematic review and meta-analysis aimed to evaluate the effect of capsaicin on weight loss in adults. We searched PubMed, Embase, China Biomedical Literature Database (CBM), Cochrane library and clinical registration centre, identifying all randomised controlled trials (RCT) published in English and Chinese to 3 May 2022. A random-effect model was used to calculate the weighted mean difference (WMD) and 95 % CI. Heterogeneity between studies was assessed by the Cochran Q statistic and I-squared tests (I 2 ). Statistical analyses were performed using STATA version 15.1. P-values < 0·05 were considered as statistically significant. From 2377 retrieved studies, fifteen studies were finally included in the meta-analyses. Fifteen RCT with 762 individuals were included in our meta-analysis. Compared with the control group, the supplementation of capsaicin resulted in significant reduction on BMI (WMD: -0·25 kg/m2, 95 % CI = -0·35, -0·15 kg/m2, P < 0·05), body weight (BW) (WMD: -0·51 kg, 95 % CI = -0·86, -0·15 kg, P < 0·05) and waist circumference (WC) (WMD: -1·12 cm, 95 % CI = -2·00, -0·24 cm, P < 0·05). We found no detrimental effect of capsaicin on waist-to-hip ratio (WMD: -0·05, 95 % CI = -0·17, 0·06, P > 0·05). The current meta-analysis suggests that capsaicin supplementation may have rather modest effects in reducing BMI, BW and WC for overweight or obese individuals.

Interventions to Address Cardiovascular Risk in Obese Patients: Many Hands Make Light Work

Obesity is a growing public health epidemic worldwide and is implicated in slowing improved life expectancy and increasing cardiovascular (CV) risk; indeed, several obesity-related mechanisms drive structural, functional, humoral, and hemodynamic heart alterations. On the other hand, obesity may indirectly cause CV disease, mediated through different obesity-associated comorbidities. Diet and physical activity are key points in preventing CV disease and reducing CV risk; however, these strategies alone are not always sufficient, so other approaches, such as pharmacological treatments and bariatric surgery, must support them. Moreover, these strategies are associated with improved CV risk factors and effectively reduce the incidence of death and CV events such as myocardial infarction and stroke; consequently, an individualized care plan with a multidisciplinary approach is recommended. More precisely, this review explores several interventions (diet, physical activity, pharmacological and surgical treatments) to address CV risk in obese patients and emphasizes the importance of adherence to treatments.

Transient Receptor Potential (TRP) based polypharmacological combination stimulates energy expending phenotype to reverse HFD-induced obesity in mice

BACKGROUND & AIM

Obesity is a worldwide epidemic leading to decreased quality of life, higher medical expenses and significant morbidity. Enhancing energy expenditure and substrate utilization in adipose tissues through dietary constituents and polypharmacological approaches is gaining importance for the prevention and therapeutics of obesity. An important factor in this regard is Transient Receptor Potential (TRP) channel modulation and resultant activation of "brite" phenotype. Various dietary TRP channel agonists like capsaicin (TRPV1), cinnamaldehyde (TRPA1), and menthol (TRPM8) have shown anti-obesity effects, individually and in combination. We aimed to determine the therapeutic potential of such combination of sub-effective doses of these agents against diet-induced obesity, and explore the involved cellular processes.

KEY FINDINGS

The combination of sub-effective doses of capsaicin, cinnamaldehyde and menthol induced "brite" phenotype in differentiating 3T3-L1 cells and subcutaneous white adipose tissue of HFD-fed obese mice. The intervention prevented adipose tissue hypertrophy and weight gain, enhanced the thermogenic potential, mitochondrial biogenesis and overall activation of brown adipose tissue. These changes observed in vitro as well as in vivo, were linked to increased phosphorylation of kinases, AMPK and ERK. In the liver, the combination treatment enhanced insulin sensitivity, improved gluconeogenic potential and lipolysis, prevented fatty acid accumulation and enhanced glucose utilization.

SIGNIFICANCE

We report on the discovery of therapeutic potential of TRP-based dietary triagonist combination against HFD-induced abnormalities in metabolic tissues. Our findings indicate that a common central mechanism may affect multiple peripheral tissues. This study opens up avenues of development of therapeutic functional foods for obesity.

Both caffeine and Capsicum annuum fruit powder lower blood glucose levels and increase brown adipose tissue temperature in healthy adult males

Using a combination of respiratory gas exchange, infrared thermography, and blood glucose (BGL) analysis, we have investigated the impact of Capsicum annuum (C. annuum) fruit powder (475 mg) or caffeine (100 mg) on metabolic activity in a placebo controlled (lactose, 100 mg) double-blinded three-way cross-over-design experiment. Metabolic measurements were made on day 1 and day 7 of supplementation in eight adult male participants (22.2 ± 2 years of age, BMI 23 ± 2 kg/m², x̅ ± SD). Participants arrived fasted overnight and were fed a high carbohydrate meal (90 g glucose), raising BGL from fasting baseline (4.4 ± 0.3 mmol/L) to peak BGL (8.5 ± 0.3 mmol/L) 45 min after the meal. Participants consumed the supplement 45 min after the meal, and both caffeine and C. annuum fruit powder restored BGL (F _(8,178) = 2.2, p = 0.02) to near fasting levels within 15 min of supplementation compared to placebo (120 min). In parallel both supplements increased energy expenditure (F _{(2, 21)} = 175.6, p < 0.001) over the 120-min test period (caffeine = 50.74 ± 2 kcal/kg/min, C. annuum fruit = 50.95 ± 1 kcal/kg/min, placebo = 29.34 ± 1 kcal/kg/min). Both caffeine and C. annuum fruit powder increased supraclavicular fossa temperature (F _(2,42) = 32, p < 0.001) on both day 1 and day 7 of testing over the 120-min test period. No statistical difference in core temperature or reference point temperature, mean arterial pressure or heart rate was observed due to supplementation nor was any statistical difference seen between day 1 and day 7 of intervention. This is important for implementing dietary ingredients as potential metabolism increasing supplements. Together the results imply that through dietary supplements such as caffeine and C. annuum, mechanisms for increasing metabolism can be potentially targeted to improve metabolic homeostasis in people.

The Role of Thermogenic Fat Tissue in Energy Consumption

Mammalian adipose tissues are broadly divided into white adipose tissue (WAT) and thermogenic fat tissue (brown adipose tissue and beige adipose tissue). Uncoupling protein 1 (UCP1) is the central protein in thermogenesis, and cells that exhibit induced UCP1 expression and appear scattered throughout WAT are called beige adipocytes, and their induction in WAT is referred to as “beiging”. Beige adipocytes can differentiate from preadipocytes or convert from mature adipocytes. UCP1 was thought to contribute to non-shivering thermogenesis; however, recent studies demonstrated the presence of UCP1-independent thermogenic mechanisms. There is evidence that thermogenic fat tissue contributes to systemic energy expenditure even in human beings. This review discusses the roles that thermogenic fat tissue plays in energy consumption and offers insight into the possibility and challenges associated with its application in the treatment of obesity and type 2 diabetes.

Capsaicin for Weight Control: “Exercise in a Pill” (or Just Another Fad)?

Medical management of obesity represents a large unmet clinical need. Animal experiments suggest a therapeutic potential for dietary capsaicin, the pungent ingredient in hot chili peppers, to lose weight. This is an attractive theory since capsaicin has been a culinary staple for thousands of years and is generally deemed safe when consumed in hedonically acceptable, restaurant-like doses. This review critically evaluates the available experimental and clinical evidence for and against capsaicin as a weight control agent and comes to the conclusion that capsaicin is not a magic “exercise in a pill”, although there is emerging evidence that it may help restore a healthy gut microbiota.

Capsaicin directly promotes adipocyte browning in the chemical compound-induced brown adipocytes converted from human dermal fibroblasts

Human brown fat is a potential therapeutic target for preventing obesity and related metabolic diseases by dissipating energy as heat through uncoupling protein 1 (UCP1). We have previously reported a method to obtain chemical compound-induced brown adipocytes (ciBAs) converted from human dermal fibroblasts under serum-free conditions. However, pharmacological responses to bioactive molecules have been poorly characterised in ciBAs. This study showed that the treatment with Capsaicin, an agonist of transient receptor potential vanilloid 1, directly activated adipocyte browning such as UCP1 expression, mitochondrial biogenesis, energy consumption rates, and glycerol recycling in ciBAs. Furthermore, genome-wide transcriptome analysis indicated that Capsaicin activated a broad range of metabolic genes including glycerol kinase and glycerol 3-phosphate dehydrogenase 1, which could be associated with the activation of glycerol recycling and triglyceride synthesis. Capsaicin also activated UCP1 expression in immortalised human brown adipocytes but inhibited its expression in mesenchymal stem cell-derived adipocytes. Altogether, ciBAs successfully reflected the direct effects of Capsaicin on adipocyte browning. These findings suggested that ciBAs could serve as a promising cell model for screening of small molecules and dietary bioactive compounds targeting human brown adipocytes.

The Multifunctional Role of Herbal Products in the Management of Diabetes and Obesity: A Comprehensive Review

Obesity and diabetes are the most demanding health problems today, and their prevalence, as well as comorbidities, is on the rise all over the world. As time goes on, both are becoming big issues that have a big impact on people’s lives. Diabetes is a metabolic and endocrine illness set apart by hyperglycemia and glucose narrow-mindedness because of insulin opposition. Heftiness is a typical, complex, and developing overall wellbeing worry that has for quite some time been connected to significant medical issues in individuals, all things considered. Because of the wide variety and low adverse effects, herbal products are an important hotspot for drug development. Synthetic compounds are not structurally diverse and lack drug-likeness properties. Thus, it is basic to keep on exploring herbal products as possible wellsprings of novel drugs. We conducted this review of the literature by searching Scopus, Science Direct, Elsevier, PubMed, and Web of Science databases. From 1990 until October 2021, research reports, review articles, and original research articles in English are presented. It provides top to bottom data and an examination of plant-inferred compounds that might be utilized against heftiness or potentially hostile to diabetes treatments. Our expanded comprehension of the systems of activity of phytogenic compounds, as an extra examination, could prompt the advancement of remedial methodologies for metabolic diseases. In clinical trials, a huge number of these food kinds or restorative plants, as well as their bioactive compounds, have been shown to be beneficial in the treatment of obesity.

Combination of TRP channel dietary agonists induces energy expending and glucose utilizing phenotype in HFD-fed mice

BACKGROUND

Bioactive dietary constituents activating Transient receptor potential (TRP) channels have emerged as promising candidates for the prevention of metabolic disorders.

OBJECTIVE

The present study is an attempt to evaluate anti-obesity potential of a dietary TRP-based tri-agonist, combination of sub-effective doses of capsaicin (TRPV1 agonist), menthol (TRPM8 agonist), and cinnamaldehyde (TRPA1 agonist) in high-fat diet (HFD)-fed mice.

DESIGN

Male C57BL/6 J mice divided into three groups (n = 8), were fed on normal pellet diet (NPD), or high-fat diet (HFD) (60% energy by fat) and HFD + CB (combination of capsaicin 0.4 mg/Kg, menthol 20 mg/Kg, and cinnamaldehyde 2 mg/Kg; p.o) for 12 weeks. Effects on HFD-induced weight gain, biochemical, histological and genomic changes in the WAT, BAT, liver and hypothalamus tissues were studied.

RESULTS

Administration of tri-agonist prevented HFD-induced increase in weight gain, improved altered morphometric parameters, glucose homeostasis, and adipose tissue hypertrophy. Tri-agonist supplementation was found to induce browning of white adipose tissue and promote brown adipose tissue activation. Enhanced glucose utilization and prevention of lipid accumulation and insulin resistance in the liver was observed in mice supplemented with a tri-agonist.

CONCLUSION

The present work provides evidence that the new approach based on combination of sub-effective doses of TRP channel agonists (TRI-AGONIST) can be employed to develop concept-based functional food for therapeutic and preventive strategies against HFD-associated pathological complications.

An update on brown adipose tissue and obesity intervention: Function, regulation and therapeutic implications

Overweight and obesity have become a world-wide problem. However, effective intervention approaches are limited. Brown adipose tissue, which helps maintain body temperature and contributes to thermogenesis, is dependent on uncoupling protein1. Over the last decade, an in-creasing number of studies have found that activating brown adipose tissue and browning of white adipose tissue can protect against obesity and obesity-related metabolic disease. Brown adipose tissue has gradually become an appealing therapeutic target for the prevention and re-versal of obesity. However, some important issues remain unresolved. It is not certain whether increasing brown adipose tissue activity is the cause or effect of body weight loss or what the risks might be for sympathetic nervous system-dependent non-shivering thermogenesis. In this review, we comprehensively summarize approaches to activating brown adipose tissue and/or browning white adipose tissue, such as cold exposure, exercise, and small-molecule treatment. We highlight the functional mechanisms of small-molecule treatment and brown adipose tissue transplantation using batokine, sympathetic nervous system and/or gut microbiome. Finally, we discuss the causality between body weight loss induced by bariatric surgery, exercise, and brown adipose tissue activity.

Signaling Targets Related to Antiobesity Effects of Capsaicin: A Scoping Review

The search for new antiobesogenic agents is increasing because of the current obesity pandemic. Capsaicin (Caps), an exogenous agonist of the vanilloid receptor of transient potential type 1 (TRPV1), has shown promising results in the treatment of obesity. This scoping review aims to verify the pathways mediating the effects of Caps in obesity and the different methods adopted to identify these pathways. The search was carried out using data from the EMBASE, MEDLINE (PubMed), Web of Science, and SCOPUS databases. Studies considered eligible evaluated the mechanisms of action of Caps in obesity models or cell types involved in obesity. Nine studies were included and 100% (n = 6) of the in vivo studies showed a high risk of bias. Of the 9 studies, 66.6% (n = 6) administered Caps orally in the diet and 55.5% (n = 5) used a concentration of Caps of 0.01% in the diet. In vitro, the most tested concentration was 1 μM (88.9%; n = 8). Capsazepine was the antagonist chosen by 66.6% (n = 6) of the studies. Seven studies (77.8%) linked the antiobesogenic effects of Caps to TRPV1 activation and 3 (33.3%) indicated peroxisome proliferator-activated receptor (PPAR) involvement as an upstream connection to TRPV1, rather than a direct metabolic target of Caps. The main secondary effects of Caps were lower weight gain (33.3%; n = 3) or loss (22.2%; n = 2), greater improvement in lipid profile (33.3%; n = 3), lower white adipocyte adipogenesis (33.3%; n = 3), browning process activation (44.4%; n = 4), and higher brown adipocyte activity (33.3%; n = 3) compared with those of the control treatment. Some studies have shown that PPAR agonists modulate TRPV1 activity, and no study has evaluated the simultaneous antagonism of these 2 receptors. Consequently, further studies are necessary to elucidate the role of each of these signaling molecules in the antiobesogenic effects of Caps.

Capsaicin and Its Effects on Body Weight

Capsaicin is a bioactive compound found in the fruits (i.e., peppers) of the plant genus Capsicum, which is widely used in many cultures. Besides many health effects of this compound, it can also be effective in body weight control through various mechanisms such as regulating lipolysis in adipocytes, increasing the feeling of satiety, stimulating energy expenditure, and reducing energy intake. This study investigated capsaicin and its effects on body weight control. In clinical studies, the amount of capsaicin affecting body weight loss differ. Longitudinal and randomized controlled studies are needed to explain the effects of capsaicin on body weight control.Key teaching points• Capsaicin can decrease hunger through hormones in the gastrointestinal tract.• Capsaicin can increase energy expenditure through brown adipose tissue.• Capsaicin can increase lipolysis in white adipose tissue.• More comprehensive studies are needed to clarify this issue.

Involvement of TRP Channels in Adipocyte Thermogenesis: An Update

Obesity prevalence became a severe global health problem and it is caused by an imbalance between energy intake and expenditure. Brown adipose tissue (BAT) is a major site of mammalian non-shivering thermogenesis or energy dissipation. Thus, modulation of BAT thermogenesis might be a promising application for body weight control and obesity prevention. TRP channels are non-selective calcium-permeable cation channels mainly located on the plasma membrane. As a research focus, TRP channels have been reported to be involved in the thermogenesis of adipose tissue, energy metabolism and body weight regulation. In this review, we will summarize and update the recent progress of the pathological/physiological involvement of TRP channels in adipocyte thermogenesis. Moreover, we will discuss the potential of TRP channels as future therapeutic targets for preventing and combating human obesity and related-metabolic disorders.

Recovery of Capsaicinoids and Other Phytochemicals Involved With TRPV-1 Receptor to Re-valorize Chili Pepper Waste and Produce Nutraceuticals

The hot chili pepper industry represents one of the most important staple foods in Mexico and many Asian countries. Nowadays, large amounts of waste materials are produced from the pepper supply chain that could be used as a source to obtain nutraceuticals. Among the most common and important bioactive compounds contained in pepper residues are the capsaicinoids, which are the responsible of the pungency of the pepper. Capsaicinoids, mainly capsaicin, may ameliorate obesity, gastric disorder, diabetes, cardiovascular diseases, cancer, rhinitis, asthma, immune system diseases, and important viral diseases as the recent COVID-19. The aim of this review is to review the industrial process for the extraction of capsaicinoids ingredients from pepper residues and to examine the relation of the capsaicin and other chili pepper phytochemicals to prevent and treat chronic diseases explained through the key role of the TRPV1 receptor. The extraction and incorporation of these compounds into nutraceutical formulations depend mainly on the development of new methods to improve not only the yield of a particular compound but the validation of the bioactivity and phytochemical characterization.

Determinants of activity of brown adipose tissue in lymphoma patients

The determinants of brown adipose tissue (BAT) activity are not yet known in detail but might serve as future therapeutic targets against obesity and the metabolic syndrome. We analyzed 235 datasets of lymphoma patients with two PET/CT examinations at different time points retrospectively. We assessed the anthropometric characteristics, features related to the metabolic syndrome, thyroid dysfunction, season of the PET/CT examination, weight change, prior cancer history, lymphoma subgroups, disease activity, and specific lymphoma-related therapies, and evaluated their association with BAT activity. We found BAT activity in 12% of all examinations, and the incidence of BAT activity after initially negative examinations was 10%. In multivariate regression analysis, the prevalence of BAT activity was associated with age, body mass index, sex, the season of the examination, diabetes mellitus, arterial hypertension, and medication on the beta-receptors. New BAT activity arose more often in patients without preceding lymphoma-related therapy. No specific medication was associated with BAT activity. In conclusion, this study confirms the potential connection of BAT with the metabolic syndrome. Preceding lymphoma-related therapy might have an inhibitory effect on the recruitment of BAT.

Effects of Capsinoid Intake on Brown Adipose Tissue Vascular Density and Resting Energy Expenditure in Healthy, Middle-Aged Adults: A Randomized, Double-Blind, Placebo-Controlled Study

Capsinoids are some of the most promising ingredients to increase energy expenditure (EE) due to brown adipose tissue (BAT) activation. However, there is limited information regarding the effect of prolonged capsinoid ingestion (CI) on BAT activity and resting EE (REE) in healthy, middle-aged, normal to overweight subjects (Sub_healthy) with distinct BAT characteristics. We examined the changes in BAT density (BAT-d), using near-infrared time-resolved spectroscopy, and REE/kg induced by daily CI. Forty Sub_healthy [age, 43.8 (mean) years; BMI, 25.4 kg/m²] received either capsinoid (9 mg/day) or a placebo daily for 6 weeks in a double-blind design. Total hemoglobin concentration in the supraclavicular region ([total-Hb]_sup), an indicator of BAT-d, and REE/kg were measured. The changes in post-intervention [total-Hb]_sup were greater in the capsinoid group (CA-G) than in the placebo group (PL-G) [5.8 µM (+12.4%) versus 1.0 µM (+2.1%); p = 0.017]. There was a significant relationship between BAT-d and REE/kg; however, post-supplementation REE/kg was not significantly different between the two groups (p = 0.228). In the overweight subgroup, changes in REE/kg were greater in the CA-G than in the PL-G [0.6 cal/kg/min (+4.3%) versus -0.3 cal/kg/min (-2.1%); p = 0.021]. CI enhanced [total-Hb]_sup, a reflection of BAT-d, showing a good correlation with REE in Sub_healthy.

Topical capsaicin cream with moderate exercise protects against hepatic steatosis, dyslipidemia and increased blood pressure in hypoestrogenic obese rats

BACKGROUND

The aim of this study was to evaluate the effects of capsaicin (Cap), moderate exercise (Ex), and their combination on arterial blood pressure (BP) and metabolic complications in hypoestrogenic (HE) obese (HEOb) rats. Female Wistar rats were ovariectomized and given 300 g L^-1 sucrose solution (HEOb), or purified water (HE) ad libitum, for 28 weeks. After shaving the abdominal skin, cold cream vehicle was applied to sedentary (Sed) and exercise (Ex) groups, and 0.75 g kg^-1 Cap cream was applied to Ex groups. Ex groups ran on a treadmill every day for 20 min at speeds from 0.15 to 0.3 m s^-1 . For combination groups (Cap + Ex), topical Cap was applied 90 min before Ex. The treatments were performed for 6 weeks, and BP was recorded before and at the end of the experimental protocol. The animals were killed by decapitation, and blood and tissues were obtained to perform oxidative profile, as well as to undertake biochemical and histologic studies.

RESULTS

Compared with individual treatments, the combined therapy (Cap + Ex) in HEOb rats caused a higher reduction in the caloric intake, body weight, abdominal fat percentage, oxidative stress, and hepatic steatosis. In HEOb groups, Cap was the only treatment that reduced BP and prevented dyslipidemia and oxidative stress.

CONCLUSION

The present data show that Cap improves the metabolic alterations induced by obesity and hypoestrogenism, suggesting that Cap can be considered as an excellent candidate for therapy of these clinical conditions. © 2020 Society of Chemical Industry.

Factors affecting the capsaicinoid profile of hot peppers and biological activity of their non-pungent analogs (Capsinoids) present in sweet peppers

Capsaicinoids are acid amides of C₉-C₁₁ branched-chain fatty acids and vanillylamine and constitute important chemical compounds of Capsicum annuum together with their non-pungent analogs (capsinoids) which have an impressive list of health benefit properties (i.e., analgesia, anti-obesity, thermogenic, cardiovascular, gastrointestinal, antioxidant, anti-bacterial, anti-virulence, anti-inflamatory, anti-diabetic, inhibits angiogenesis, and improves glucose metabolism) . In this review, the state of art on how capsaicinoids are affected by different pre- and postharvest factors is discussed together with their biological activity. For instance, high light intensity and heat treatments may reduce capsaicinoid content in fruits probably due to the loss of activity of capsaicin synthase (CS) and phenylalanine ammonia lyase (PAL). The pungency in peppers varies also with environment, genotype or cultivar, node position, fruiting and maturity stages, nitrogen and potassium contents. As the fruit mature, capsaicinoid levels increase. Fruits from the second node tend to have higher accumulation of pungency than those of other positions and the pungency decreases linearly as the node position increase. Sodium hydroxide treatment reduces the pungency of pepper fruit as it hydrolyzes and modifies one of the features (vanillyl group, the acid-amide linkage and alkyl side chain) of capsaicin molecule. Salt and water stress increase PAL and capsaicin synthase activity and increase the capsaicinoid accumulation in fruit, by negatively regulating peroxidase activity at appropriate levels. Future research must be directed in better understanding the changes of capsinoids during pre and post-harvest management, the causal drivers of the loss of activity of the aminotransferase gene (pAMT) and if possible, studies with genetically modified sweet peppers with functional pAMT. Available data provided in this review can be used in different agricultural programs related to developing new cultivars with specific pungency levels. The contents of capsaicinoids and capsinoids in both fresh fruits and marketed products are also of remarkable importance considering the preferences of certain niches in market where higher added-value products might be commercialized.

Brown fat activity determined by infrared thermography and thermogenesis measurement using whole body calorimetry (BRIGHT Study)

To assess BAT activity in humans at a population level, infrared thermography (IRT) represents a safe, readily repeatable and affordable alternative to 18F-FDG-PET. Building upon a previously proposed method by our laboratory, we further refined the image computational algorithm to quantify BAT activation in the cervical-supraclavicular (C-SCV) region of healthy young men under thermo-neutral and cold exposure conditions. Additionally, we validated the whole-body calorimeter (WBC) in reliably measuring cold-induced thermogenesis. The temperature gradient between C-SCV-deltoid regions, and the corresponding difference in heat power output, increased upon cold air exposure relative to thermo-neutral conditions (by 74.88 %, p<0.0001; and by 71.34 %, p<0.0001 respectively). Resting and cumulative energy expenditure (EE) rose significantly (by 13.14 % and 9.12 % respectively, p=0.0001) while positive correlations between IRT measures and EE were found with cold air exposure (percentage change in heat power gradient between ROI and deltoid, cold air: r(2)=0.29, p=0.026, Pearson's correlation). IRT and WBC can be used to study BAT activation. The refined algorithm allows for more automation and objectivity in IRT data analysis, especially under cold air exposures.

Nitrogen Source Affects the Composition of Metabolites in Pepper (Capsicum annuum L.) and Regulates the Synthesis of Capsaicinoids through the GOGAT-GS Pathway

Phytochemical analyses of pepper fruit metabolites have been reported; however, much less is known about the influence of different forms of nitrogen (N), which is critical for plant growth and fruit quality formation. The "Longjiao No. 5" variety (Capsicum annuum L.) grown in Northwestern China was profiled using liquid chromatography-mass spectrometry (LC-MS) coupled with multivariate data analysis to explore the composition of different metabolites in pericarp and placenta, and to investigate the effect of three ammonium (NH4+)-to-nitrate (NO3-) ratios (0:100, 25:75, and 50:50). A total of 215 metabolites were obtained by qualitative analysis, where 31 metabolites were the major differential metabolite components of pepper fruits between placenta and pericarp, and 25 among N treatments. The addition of ammonium up-regulated carbohydrates, such as α-lactose and sucrose, as well as phenylalanine lyase (PAL) of placenta tissue. The supply of 25% NH4+-N and 75% NO3--N exhibited a relatively higher levels of ascorbic acid in pericarp and amino acids, capsaicin, and dihydrocapsaicin in placenta, and led to higher fruit weight among the ammonium-to-nitrate ratios. The expression and activities of glutamic acid synthetase (GOGAT) and glutamine synthetase (GS) that are involved in ammonium assimilation were affected by adjusting the ammonium-N proportion, and they were significantly positively correlated with capsaicin, dihydrocapsaicin contents, capsaicinoid synthetase (CS), as well as the relative expression levels of genes related to capsaicinoid biosynthesis, such as acyltransferase 3 (AT3) and acyl-ACP thioesterase (FatA).

Effects of Capsinoids on Daily Physical Activity, Body Composition and Cold Hypersensitivity in Middle-Aged and Older Adults: A Randomized Study

Sedentary/inactive lifestyle leads middle-aged and older adults to metabolic syndrome and frailty. Capsinoids from nonpungent chili pepper cultivar have been reported to reduce body fat mass, promote metabolism, and improve unidentified complaints of chills. Additionally, they have an anti-inflammation effect; therefore, we hypothesized that continuous oral ingestion of capsinoids alleviates age-related inflammation in the brain and improves the physical activity (PA) in middle-aged and older adults. In our double-blind human study, 69 participants (17 male, 52 female; mean age: 74.1 ± 7.7 years; range: 52–87 years) were administered either 9 mg of capsinoids which were extracted from pepper fruit variety CH-19 Sweet (Capsicum anuum L.) (CP group), or a placebo (PL group) daily over a 3 month period. In an animal study, PA and inflammation-related mRNA expression in the brain were examined in 5-week (young) and 53-week (old) aged mice fed a diet with or without 0.3% dihydrocapsiate, a type of capsinoids, for 12 weeks. In a human study, capsinoids intake did not increase the amount of light-to-moderate PA less than 6.0 metabolic equivalents (METs) (CP: 103.0 ± 28.2 at baseline to 108.2 ± 28.3 at 12 weeks; PL: 104.6 ± 19.8 at baseline to 115.2 ± 23.6 at 12 weeks, METs × hour/week); however, in participants exhibiting an inactive lifestyle, it showed significant increase (CP: 84.5 ± 17.2 at baseline to 99.2 ± 24.9 at 12 weeks; PL: 99.7 ± 23.3 at baseline to 103.8 ± 21.9 at 12 weeks). The energy expenditure in physical activity also improved in the inactive CP group (CP: 481.2 ± 96.3 at baseline to 562.5 ± 145.5 at 12 weeks; PL: 536.8 ± 112.2 at baseline to 598.6 ± 127.6 at 12 weeks; kcal/day). In all participants, CP showed reduced waist circumference, percent body fat, and visceral fat volume; in addition, chills were eased in subjects aged 80 years and older. The older mice fed capsinoids showed increased locomotion activity, decreased inflammation, and oxidative stress in the brain. The results suggest that the continuous oral ingestion of capsinoids gains PA through anti-inflammation effect in the brain as well as reduces fat accumulation and chills in inactive and older humans.

Near-Infrared Time-Resolved Spectroscopy for Assessing Brown Adipose Tissue Density in Humans: A Review

Brown adipose tissue (BAT) mediates adaptive thermogenesis upon food intake and cold exposure, thus potentially contributing to the prevention of lifestyle-related diseases. ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) with computed tomography (CT) (¹⁸FDG-PET/CT) is a standard method for assessing BAT activity and volume in humans. ¹⁸FDG-PET/CT has several limitations, including high device cost and ionizing radiation and acute cold exposure necessary to maximally stimulate BAT activity. In contrast, near-infrared spectroscopy (NIRS) has been used for measuring changes in O₂-dependent light absorption in the tissue in a non-invasive manner, without using radiation. Among NIRS, time-resolved NIRS (NIR_TRS) can quantify the concentrations of oxygenated and deoxygenated hemoglobin ([oxy-Hb] and [deoxy-Hb], respectively) by emitting ultrashort (100 ps) light pulses and counts photons, which are scattered and absorbed in the tissue. The basis for assessing BAT density (BAT-d) using NIR_TRS is that the vascular density in the supraclavicular region, as estimated using Hb concentration, is higher in BAT than in white adipose tissue. In contrast, relatively low-cost continuous wavelength NIRS (NIR_CWS) is employed for measuring relative changes in oxygenation in tissues. In this review, we provide evidence for the validity of NIR_TRS and NIR_CWS in estimating human BAT characteristics. The indicators (Ind_NIRS) examined were [oxy-Hb]_sup, [deoxy-Hb]_sup, total hemoglobin [total-Hb]_sup, Hb O₂ saturation (StO_2sup), and reduced scattering coefficient ( μs sup' ) in the supraclavicular region, as determined by NIR_TRS, and relative changes in corresponding parameters, as determined by NIR_CWS. The evidence comprises the relationships between the Ind_NIRS investigated and those determined by ¹⁸FDG-PET/CT; the correlation between the Ind_NIRS and cold-induced thermogenesis; the relationship of the Ind_NIRS to parameters measured by ¹⁸FDG-PET/CT, which responded to seasonal temperature fluctuations; the relationship of the Ind_NIRS and plasma lipid metabolites; the analogy of the Ind_NIRS to chronological and anthropometric data; and changes in the Ind_NIRS following thermogenic food supplementation. The [total-Hb]_sup and [oxy-Hb]_sup determined by NIR_TRS, but not parameters determined by NIR_CWS, exhibited significant correlations with cold-induced thermogenesis parameters and plasma androgens in men in winter or analogies to ¹⁸FDG-PET. We conclude that NIR_TRS can provide useful information for assessing BAT-d in a simple, rapid, non-invasive way, although further validation study is still needed.

Uncovering the Role of p38 Family Members in Adipose Tissue Physiology

The complex functions of adipose tissue have been a focus of research interest over the past twenty years. Adipose tissue is not only the main energy storage depot, but also one of the largest endocrine organs in the body and carries out crucial metabolic functions. Moreover, brown and beige adipose depots are major sites of energy expenditure through the activation of adaptive, non-shivering thermogenesis. In recent years, numerous signaling molecules and pathways have emerged as critical regulators of adipose tissue, in both homeostasis and obesity-related disease. Among the best characterized are members of the p38 kinase family. The activity of these kinases has emerged as a key contributor to the biology of the white and brown adipose tissues, and their modulation could provide new therapeutic approaches against obesity. Here, we give an overview of the roles of the distinct p38 family members in adipose tissue, focusing on their actions in adipogenesis, thermogenic activity, and secretory function.

Paprika and/or marigold extracts improve productivity and yolk color in egg-laying quails

Abstract This study was conducted to evaluate the effects of paprika and marigold extracts on the productivity of Japanese quails, quality and sensorial analysis of eggs. Japanese quails were allocated in a completely randomized design and factorial arrangement 2 × 2 + 1, and four replicates. Diets were formulated based on: 1) corn (control), and 2) sorghum (S) without pigments, 3) S + 0.06% paprika extract (PE), 4) S + 0.01% marigold extract (ME), and 5) S + 0.06% PE and 0.01% ME. There was no effect of the control and factorial interaction on feed intake, egg-laying rate, or egg mass; however, the feed: gain ratio was lower among quail fed with diets containing both extracts. The inclusion of PE and ME in the diets improved the feed: gain ratio and yolk color; the inclusion of PE reduced the feed intake and specific weight of the eggs. Compared to the control, treatments based on sorghum or sorghum + PE led to a difference in egg taste and yolk color in the sensorial visit the website to get the how analysis. It was concluded that paprika and marigold extracts could be included in quail diets because of improvements in feed: gain ratio and yolk color.

Biological Evaluation of Natural and Synthesized Homovanillic Acid Esters as Inhibitors of Intestinal Fatty Acid Uptake in Differentiated Caco-2 Cells

With raising prevalence of obesity, the regulation of human body fat is increasingly relevant. The modulation of fatty acid uptake by enterocytes represents a promising target for body weight maintenance. Recent results demonstrated that the trigeminal active compounds capsaicin, nonivamide, and trans-pellitorine dose-dependently reduce fatty acid uptake in differentiated Caco-2 cells as a model for the intestinal barrier. However, non-pungent alternatives have not been investigated and structural determinants for the modulation of intestinal fatty acid uptake have not been identified so far. Thus, based on the previous results, we synthesized 23 homovanillic acid esters in addition to the naturally occurring capsiate and screened them for their potential to reduce intestinal fatty acid uptake using the fluorescent fatty acid analog Bodipy-C12 in differentiated Caco‑2 cells as an enterocyte model. Whereas pre-incubation with 100 µM capsiate did not change fatty acid uptake by Caco-2 enterocytes, a maximum inhibition of −47% was reached using 100 µM 1‑methylpentyl-2-(4-hydroxy-3-methoxy-phenyl)acetate. Structural analysis of the 24 structural analogues tested in the present study revealed that a branched fatty acid side chain, independent of the chain length, is one of the most important structural motifs associated with inhibition of fatty acid uptake in Caco-2 enterocytes. The results of the present study may serve as an important basis for designing potent dietary inhibitors of fatty acid uptake.

Transient Receptor Potential Channels and Metabolism

Transient receptor potential (TRP) channels are nonselective cationic channels, conserved among flies to humans. Most TRP channels have well known functions in chemosensation, thermosensation, and mechanosensation. In addition to being sensing environmental changes, many TRP channels are also internal sensors that help maintain homeostasis. Recent improvements to analytical methods for genomics and metabolomics allow us to investigate these channels in both mutant animals and humans. In this review, we discuss three aspects of TRP channels, which are their role in metabolism, their functional characteristics, and their role in metabolic syndrome. First, we introduce each TRP channel superfamily and their particular roles in metabolism. Second, we provide evidence for which metabolites TRP channels affect, such as lipids or glucose. Third, we discuss correlations between TRP channels and obesity, diabetes, and mucolipidosis. The cellular metabolism of TRP channels gives us possible therapeutic approaches for an effective prophylaxis of metabolic syndromes.

Phytochemicals as potential candidates to combat obesity via adipose non-shivering thermogenesis

Obesity is a chronic metabolic disease caused by a long-term imbalance between energy intake and expenditure. The discovery of three different shades of adipose tissues has implications in terms of understanding the pathogenesis and potential interventions for obesity and its related complications. Fat browning, as well as activation of brown adipocytes and new beige adipocytes differentiated from adipogenic progenitor cells, are emerging as interesting and promising methods to curb obesity because of their unique capacity to upregulate non-shivering thermogenesis. This capacity is due to catabolism of stored energy to generate heat through the best characterized thermogenic effector uncoupling protein 1 (UCP1). A variety of phytochemicals have been shown in the literature to contribute to thermogenesis by acting as chemical uncouplers, UCP1 inducers or regulators of fat differentiation and browning. In this review, we summarize the mechanisms and strategies for targeting adipose-mediated thermogenesis and highlight the role of phytochemicals in targeting adipose thermogenesis to fight against obesity. We also discuss proposed targets for how these phytochemical molecules promote BAT activity, WAT browning and beige cell development, thereby offering novel insights into interventional strategies of how phytochemicals may help prevent and manage obesity via adipose thermogenesis.

From white to beige adipocytes: therapeutic potential of dietary molecules against obesity and their molecular mechanisms

The global incidence of obesity and its complications continue to rise along with a demand for novel therapeutic approaches. In addition to classic brown adipose tissue (BAT), the formation of brown-like adipocytes called beige adipocytes, within white adipose tissue (WAT), has attracted much attention as a therapeutic target due to its inducible features when stimulated, resulting in the dissipation of extra energy as heat. There are various dietary agents that are able to modulate the beige-development process by interacting with critical molecular signaling cascades, leading to the enhancement of thermogenesis. Although challenges still remain regarding the origin of the beige adipocytes, the crosstalk with activation of BAT and induction of the beiging of white fat may provide attractive potential strategies for management of obesity.

The role of brown and beige adipose tissue in glycaemic control

For the past decade, brown adipose tissue (BAT) has been extensively studied as a potential therapy for obesity and metabolic diseases due to its thermogenic and glucose-consuming properties. It is now clear that the function of BAT goes beyond heat production, as it also plays an important endocrine role by secreting the so-called batokines to communicate with other metabolic tissues and regulate systemic energy homeostasis. However, despite numerous studies showing the benefits of BAT in rodents, it is still not clear whether recruitment of BAT can be utilized to treat human patients. Here, we review the advances on understanding the role of BAT in metabolism and its benefits on glucose and lipid homeostasis in both humans and rodents. Moreover, we discuss the latest methodological approaches to assess the contribution of BAT to human metabolism as well as the possibility to target BAT, pharmacologically or by lifestyle adaptations, to treat metabolic disorders.

Combination of Capsaicin and Capsiate Induces Browning in 3T3-L1 White Adipocytes via Activation of the Peroxisome Proliferator-Activated Receptor γ/β3-Adrenergic Receptor Signaling Pathways

This study investigated the effects and molecular mechanism of a combination of capsaicin and capsiate on promoting lipid metabolism and inducing browning in 3T3-L1 white adipocytes. The combination significantly suppressed lipid accumulation in adipocytes ( p = 0.019) and robustly improved lipid metabolic profiles, including decreased triacylglycerol (0.6703 ± 0.0385 versus 0.2849 ± 0.0188 mmol/g of protein; p < 0.001), total cholesterol (0.1282 ± 0.0241 versus 0.0651 ± 0.0178 mmol/g of protein; p = 0.003), and low-density lipoprotein cholesterol (0.0021 ± 0.0017 versus 0.0005 ± 0.0002 mmol/g of protein; p = 0.024) and increased high-density lipoprotein cholesterol (0.0162 ± 0.0141 versus 0.1002 ± 0.0167 mmol/g of protein; p = 0.012). Furthermore, this combination markedly upgraded the protein levels of cluster of differentiation 36 ( p = 0.007) and adipose triglyceride lipase ( p = 0.013) and phosphorylation of hormone-sensitive lipase at Ser660, Ser565, and Ser563 ( p < 0.001, p = 0.027, and p = 0.002, respectively), indicating increases of fatty acid transport and lipolysis. The levels of lipid metabolism regulators, phosphorylation of adenosine-monophosphate-activated protein kinases α and β ( p = 0.011, and p < 0.001, respectively), sirtuin 1 ( p = 0.004), and vanilloid transient receptor subtype I ( p = 0.014) were also increased by the combination. Moreover, the combination greatly activated the browning program in adipocytes, as demonstrated by increases in beige-specific gene and protein. Further research found that the protein levels of peroxisome proliferator-activated receptor γ (PPARγ; p = 0.001) and β₃-adrenergic receptor (β₃-AR; p = 0.026) were elevated by the combination, and most of the beige-specific markers were abolished by pretreatment of antagonists of PPARγ or β₃-AR. In conclusion, these results indicated that a combination of capsaicin and capsiate could induce browning in white adipocytes via activation of the PPARγ/β₃-AR signaling pathway, and this combination might be worth investigating as a potential cure for obesity.

Guarana supplementation attenuated obesity, insulin resistance, and adipokines dysregulation induced by a standardized human Western diet via brown adipose tissue activation

Obesity is a metabolic disorder associated with adverse health consequences that has increased worldwide at an epidemic rate. This has encouraged many people to utilize nonprescription herbal supplements for weight loss without knowledge of their safety or efficacy. However, mounting evidence has shown that some herbal supplements used for weight loss are associated with adverse effects. Guarana seed powder is a popular nonprescription dietary herb supplement marketed for weight loss, but no study has demonstrated its efficacy or safety when administered alone. Wistar rats were fed four different diets (low-fat diet and Western diet with or without guarana supplementation) for 18 weeks. Metabolic parameters, gut microbiota changes, and toxicity were then characterized. Guarana seed powder supplementation prevented weight gain, insulin resistance, and adipokine dysregulation induced by Western diet compared with the control diet. Guarana induced brown adipose tissue expansion, mitochondrial biogenesis, uncoupling protein-1 overexpression, AMPK activation, and minor changes in gut microbiota. Molecular docking suggested a direct activation of AMPK by four guarana compounds tested here. We propose that brown adipose tissue activation is one of the action mechanisms involved in guarana supplementation-induced weight loss and that direct AMPK activation may underlie this mechanism. In summary, guarana is an attractive potential therapeutic agent to treat obesity.

Activation of Human Brown Adipose Tissue by Capsinoids, Catechins, Ephedrine, and Other Dietary Components: A Systematic Review

Human brown adipose tissue (BAT) has attracted clinical interest not only because it dissipates energy but also for its potential capacity to counteract obesity and related metabolic disorders (e.g., insulin resistance and dyslipidemia). Cold exposure is the most powerful stimulus for activating and recruiting BAT, and this stimulatory effect is mediated by the transient receptor potential (TRP) channels. BAT can also be activated by other receptors such as the G-protein-coupled bile acid receptor 1 (GPBAR1) or β-adrenergic receptors. Interestingly, these receptors also interact with several dietary components; in particular, capsinoids and tea catechins appear to mimic the effects of cold through a TRP-BAT axis, and they consequently seem to decrease body fat and improve metabolic blood parameters. This systematic review critically addresses the evidence behind the available human studies analyzing the effect of several dietary components (e.g., capsinoids, tea catechins, and ephedrine) on BAT activity. Even though the results of these studies are consistent with the outcomes of preclinical models, the lack of robust study designs makes it impossible to confirm the BAT-activation capacity of the specified dietary components. Further investigation into the effects of dietary components on BAT is warranted to clarify to what extent these components could serve as a powerful strategy to treat obesity and related metabolic disorders.

Brown and Brite: The Fat Soldiers in the Anti-obesity Fight

Brown adipose tissue (BAT) is proposed to maintain thermal homeostasis through dissipation of chemical energy as heat by the uncoupling proteins (UCPs) present in their mitochondria. The recent demonstration of the presence of BAT in humans has invigorated research in this area. The research has provided many new insights into the biology and functioning of this tissue and the biological implications of its altered activities. Another finding of interest is browning of white adipose tissue (WAT) resulting in what is known as beige/brite cells, which have increased mitochondrial proteins and UCPs. In general, it has been observed that the activation of BAT is associated with various physiological improvements such as a reduction in blood glucose levels increased resting energy expenditure and reduced weight. Given the similar physiological functions of BAT and beige/ brite cells and the higher mass of WAT compared to BAT, it is likely that increasing the brite/beige cells in WATs may also lead to greater metabolic benefits. However, development of treatments targeting brown fat or WAT browning would require not only a substantial understanding of the biology of these tissues but also the effect of altering their activity levels on whole body metabolism and physiology. In this review, we present evidence from recent literature on the substrates utilized by BAT, regulation of BAT activity and browning by circulating molecules. We also present dietary and pharmacological activators of brown and beige/brite adipose tissue and the effect of physical exercise on BAT activity and browning.

The Immunomodulatory and Anti-Inflammatory Role of Polyphenols

This review offers a systematic understanding about how polyphenols target multiple inflammatory components and lead to anti-inflammatory mechanisms. It provides a clear understanding of the molecular mechanisms of action of phenolic compounds. Polyphenols regulate immunity by interfering with immune cell regulation, proinflammatory cytokines' synthesis, and gene expression. They inactivate NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) and modulate mitogen-activated protein Kinase (MAPk) and arachidonic acids pathways. Polyphenolic compounds inhibit phosphatidylinositide 3-kinases/protein kinase B (PI3K/AkT), inhibitor of kappa kinase/c-Jun amino-terminal kinases (IKK/JNK), mammalian target of rapamycin complex 1 (mTORC1) which is a protein complex that controls protein synthesis, and JAK/STAT. They can suppress toll-like receptor (TLR) and pro-inflammatory genes' expression. Their antioxidant activity and ability to inhibit enzymes involved in the production of eicosanoids contribute as well to their anti-inflammation properties. They inhibit certain enzymes involved in reactive oxygen species ROS production like xanthine oxidase and NADPH oxidase (NOX) while they upregulate other endogenous antioxidant enzymes like superoxide dismutase (SOD), catalase, and glutathione (GSH) peroxidase (Px). Furthermore, they inhibit phospholipase A2 (PLA2), cyclooxygenase (COX) and lipoxygenase (LOX) leading to a reduction in the production of prostaglandins (PGs) and leukotrienes (LTs) and inflammation antagonism. The effects of these biologically active compounds on the immune system are associated with extended health benefits for different chronic inflammatory diseases. Studies of plant extracts and compounds show that polyphenols can play a beneficial role in the prevention and the progress of chronic diseases related to inflammation such as diabetes, obesity, neurodegeneration, cancers, and cardiovascular diseases, among other conditions.

Potential Phytopharmacy and Food Applications of Capsicum spp.: A Comprehensive Review

Capsicum genus (Solanaceae) is native to the Americas. Today, it is an important agricultural crop cultivated around the world, not only due to its economic importance, but also for the nutritional value of the fruits. Among their phytochemical constituents, capsaicinoids are characteristic and responsible of the pungency of sharp-tasting cultivars. Moreover, Capsicum and capsaicinoids (mainly, capsaicin) have been largely studied because of their health benefits. Thus, this study reviews the scientific knowledge about Capsicum spp. and their phytochemicals against cancer, diabetes, gastrointestinal diseases, pain, and metabolic syndrome, as well as their antioxidant and antimicrobial activity. These bioactivities can be the basis of the formulation of functional ingredients and natural preservatives containing Capsicum extracts or isolated compounds.

Role of Thermo-Sensitive Transient Receptor Potential Channels in Brown Adipose Tissue

Brown and beige adipocytes are a major site of mammalian non-shivering thermogenesis and energy dissipation. Obesity is caused by an imbalance between energy intake and expenditure and has become a worldwide health problem. Therefore modulation of thermogenesis in brown and beige adipocytes could be an important application for body weight control and obesity prevention. Over the last few decades, the involvement of thermo-sensitive transient receptor potential (TRP) channels (including TRPV1, TRPV2, TRPV3, TRPV4, TRPM4, TRPM8, TRPC5, and TRPA1) in energy metabolism and adipogenesis in adipocytes has been extensively explored. In this review, we summarize the expression, function, and pathological/physiological contributions of these TRP channels and discuss their potential as future therapeutic targets for preventing and combating human obesity and obesity-related metabolic disorders.

Improvement of Lipid and Glucose Metabolism by Capsiate in Palmitic Acid-Treated HepG2 Cells via Activation of the AMPK/SIRT1 Signaling Pathway

Capsiate, a nonpungent ingredient of CH-19 Sweet, exhibits anti-obesity effects on animals and humans. This study investigated the effects and molecular mechanism of capsiate on lipid and glucose metabolism in PA-treated HepG2 cells. Results showed that compared with the PA-alone group, 100 μM capsiate inhibited lipid accumulation, decreased TG (0.0562 ± 0.0142 vs 0.0381 ± 0.0055 mmol/g of protein; P = 0.024) and TC (0.1087 ± 0.0037 vs 0.0359 ± 0.0059 mmol/g of protein; P = 0.000) levels, and increased the HDL-C level (0.0189 ± 0.0067 vs 0.1050 ± 0.0106 mmol/g of protein; P = 0.000) and glycogen content (0.0065 ± 0.0007 vs 0.0146 ± 0.0008 mg/10⁶ cells; P = 0.000) of PA-treated HepG2 cells; 100 μM capsiate also upregulated the level of CD36 ( P = 0.000), phosphorylation of ACC ( P = 0.034), and expression of CPT1 ( P = 0.013) in PA-treated HepG2 cells, leading to an enhancement of lipid metabolism. Meanwhile, 100 μM capsiate upregulated the levels of GLUT1, GLUT4, GK, and phosphorylation of GS ( P = 0.001, 0.029, 0.000, and 0.045, respectively) and downregulated the PEPCK level ( P = 0.001) to improve glucose metabolism in PA-treated HepG2 cells. Furthermore, the levels of phosphorylation of AMPK and expression of SIRT1 in HepG2 cells were increased by a 100 μM capsiate treatment ( P = 0.001 and 0.000, respectively), while the FGF21 level was decreased ( P = 0.003). Most of these effects were reversed by pretreatment with compound C, a selective AMPK inhibitor. Thus, capsiate might improve lipid and glucose metabolism in HepG2 cells by activating the AMPK/SIRT1 signaling pathway.

Role of Human Brown Fat in Obesity, Metabolism and Cardiovascular Disease: Strategies to Turn Up the Heat

Human brown adipose tissue (BAT) was re-discovered in 2009 by several independent groups, who showed that it is present and active in adults, as judged from the profound uptake of the glucose analogue radiotracer ¹⁸F-fluorodeoxyglucose in positron-emission tomography and computed tomography scan analysis after cold exposure. A potential clinical implication of activating BAT relates to its high metabolic activity and its potential role in stimulating energy expenditure (i.e. resting energy expenditure, meal-induced thermogenesis, and cold-induced thermogenesis), which makes it an attractive target to reduce adiposity. Moreover, due to its ability to oxidise glucose and lipids, BAT activation may also potentially exert beneficial metabolic and cardiovascular effects through reducing glucose and lipid levels, respectively. This review describes the potential role of human BAT in the prevention and treatment of obesity, metabolism, and cardiovascular disease focusing on its impact on energy expenditure and management of body fat accumulation as well as on glucose and lipid metabolism. This article also summarises the strategies that are currently being studied to activate human BAT.

Is activation of human brown adipose tissue a viable target for weight management?

To date, human studies show that brown adipose tissue (BAT) contributes a small yet highly variable amount to overall energy expenditure. No studies have shown a decrease in body weight with cold-induced BAT activation, and existing pharmacological studies suggest that BAT activation via the sympathetic nervous system may result in increased heart rate and systolic blood pressure. Furthermore, even though the amount and/or activity of BAT have been shown to vary with seasons, such variation does not seem to be translated into weight changes. Collectively, these findings do not support the use of BAT activation for weight loss in humans; however, the potential role of BAT in counteracting the metabolic adaptation observed with weight loss is suggested. Although the role of BAT in weight control is currently unsubstantiated, BAT may play a role in improving insulin sensitivity in humans.

Effects of Shiitake Intake on Serum Lipids in Rats Fed Different High-Oil or High-Fat Diets

Shiitake (Lentinula edodes) extract, eritadenine, has been shown to reduce cholesterol levels, and its hypocholesterolemic actions are involved in the metabolism of methionine. However, the mechanisms by which eritadenine affects cholesterol metabolism in animals fed a high-fat diet containing different sources of lipids have not yet been elucidated in detail. This study was conducted to investigate the effects of shiitake supplementation on serum lipid concentrations in rats fed a diet including a high amount of a plant oil (HO [high oil] and HOS [high oil with shiitake] groups), animal fat (HF [high fat] and HFS [high fat with shiitake] groups), or MCT- (medium-chain triglyceride-) rich plant oil (HM [high MCT] and HMS [high MCT with shiitake] groups). Rats in the HOS, HFS, and HMS groups were fed shiitake. When rats were fed a diet containing shiitake, serum triglyceride, cholesterol levels, and LCAT (lecithin-cholesterol acyltransferase) activities were lower in rats given MCT-rich plant oil than in those that consumed lard. The lipid type in the diet with shiitake also affected serum cholesterol levels and LCAT activities. The diet containing MCT-rich plant oil showed the greatest rates of decrease in all serum lipid profiles and LCAT activities. These results suggest that shiitake and MCT-rich plant oil work together to reduce lipid profiles and LCAT activity in serum.

Daily intake of Kaempferia parviflora extract decreases abdominal fat in overweight and preobese subjects: a randomized, double-blind, placebo-controlled clinical study

PURPOSE

Obesity is a serious problem, which is now a worldwide health problem. Kaempferia parviflora extract (KPE) exhibits anti-obesity effects in animals. However, as no clinical trials have evaluated the anti-obesity effects of KPE in humans, we examined the effects of KPE in reducing abdominal fat in overweight and preobese Japanese subjects.

MATERIALS AND METHODS

A 12-week, single-center, randomized, double-blind, placebo-controlled clinical trial was conducted. Seventy-six subjects (males and females aged 20 to <65 years) with a body mass index ≥24 and <30 kg/m² were randomly assigned into two groups. The subjects in each group ingested one capsule of placebo or active KPE (containing 150 mg of KPE) once daily for 12 weeks. The primary outcome was reduction in visceral fat area as determined by computed tomography scanning. The key secondary outcomes were reductions in subcutaneous fat area and total fat area. Subgroup analysis was also performed in healthy subjects without dyslipidemia, hypertension, or hyperglycemia. The safety of KPE ingestion was also evaluated.

RESULTS

Compared with the placebo group, the active KPE group exhibited significant reduction in abdominal fat area (visceral, subcutaneous, and total fat) and triglyceride levels after 12 weeks. Subgroup analyses demonstrated a significant reduction in abdominal fat area and triglyceride levels in healthy subjects compared with the placebo group after 12 weeks. Neither group exhibited adverse events related to the test foods or clinically relevant abnormal changes in physical, biochemical, or hematologic parameters, or in urinalysis results and medical interview.

CONCLUSION

Daily ingestion of KPE safely reduces body fat, particularly abdominal fat, in Japanese overweight and preobese subjects.