Effects of red pepper added to high-fat and high-carbohydrate meals on energy metabolism and substrate utilization in Japanese women

Bioeconomy and ethnopharmacology - Translational perspective and sustainability of the bioresources of northeast region of India

ETHNOPHARMACOLOGICAL RELEVANCE

The ecological environment of Northeast region of India (NER), with its high humidity, has resulted in greater speciation and genetic diversity of plant, animal, and microbial species. This region is not only rich in ethnic and cultural diversity, but it is also a major biodiversity hotspot. The sustainable use of these bioresources can contribute to the region's bioeconomic development.

AIM OF THE STUDY

The review aimed to deliver various perspectives on the development of bioeconomy from NER bioresources under the tenets of sustainable utilization and socioeconomic expansion.

MATERIALS AND METHODS

Relevant information related to prospects of the approaches and techniques pertaining to the sustainable use of ethnomedicine resources for the growth of the bioeconomy were retrieved from PubMed, ScienceDirect, Google Scholar, Scopus, and Springer from 1984 to 2023. All the appropriate abstracts, full-text articles and various book chapters on bioeconomy and ethnopharmacology were conferred.

RESULT

As the population grows, so does the demand for basic necessities such as food, health, and energy resources, where insufficient resource utilization and unsustainable pattern of material consumption cause impediments to economic development. On the other hand, the bioeconomy concept leads to "the production of renewable biological resources and the conversion of these resources and waste streams into value-added products.

CONCLUSIONS

In this context, major emphasis should be placed on strengthening the economy's backbone in order to ensure sustainable use of these resources and livelihood security; in other words, it can boost the bio-economy by empowering the local people in general.

Function and mechanism of action of the TRPV1 channel in the development of triple-negative breast cancer

Transient receptor potential channel subfamily vanilloid 1 (TRPV1) is a member of the transient receptor potential family of nonselective cationic transmembrane channel proteins that are involved in the regulation of calcium homeostasis. It is expressed in various tumor types and has been implicated in the regulation of cancer growth, metastasis, apoptosis, and cancer-related pain. TRPV1 is highly expressed in triple-negative breast cancer (TNBC), and both its agonists and antagonists may exert anti-cancer effects. In this review, we provide an overview of the effect of TRPV1 on TNBC development and its influence on immunotherapy in an attempt to facilitate the development of future treatment strategies.

Association of dietary patterns and sarcopenia in the elderly population: a cross-sectional study

Background: Sarcopenia, defined as the loss of muscle mass and strength, has been associated with increased hospitalization and mortality. Dietary pattern analysis is a whole diet approach which in this study was used to investigate the relationship between diet and sarcopenia. This study aims to estimate the prevalence of sarcopenia and explore possible factors associated with it among a large population in Beijing, China. Methods: A cross-sectional study with 1,059 participants aged more than 50 years was performed. Sarcopenia was defined based on the guidelines of the Asian Working Group for Sarcopenia. The total score of the MNA-SF questionnaire was used to analyse nutrition status. The baseline demographic information, diet structure and eating habits were collected by clinicians trained in questionnaire data collection and anthropometric and bioimpedance measurements. Results: The overall prevalence of sarcopenia was 8.8% and increased with age: 5%, 5.8%, 10.3% and 26.2% in the 50-59, 60-69, 70-79, and ≥80 years groups, respectively. Marital status (with or without a spouse) was not an independent factor associated with sarcopenia adjusted by age and sex. However, nutritional risk or malnutrition, vegetable diet, advanced age and spicy eating habits were risk factors for sarcopenia. Meanwhile, daily fruit, dairy and nut consumption were protective factors against sarcopenia adjusted by age, sex, income status and spouse status. Conclusion: Although further studies are required to explore the association between healthy dietary patterns and the risk of sarcopenia, the present study provides basic data for identifying correlates of sarcopenia in elderly Chinese individual.

Functional expression of the thermally activated transient receptor potential channels TRPA1 and TRPM8 in human myotubes

Transient potential (TRP) ion channels expressed in primary sensory neurons act as the initial detectors of environmental cold and heat, information which controls muscle energy expenditure. We hypothesize that non-neuronal TRPs have direct cellular responses to thermal exposure, also affecting cellular metabolism. In the present study we show expression of TRPA1, TRPM8 and TRPV1 in rat skeletal muscle and human primary myotubes by qPCR. Effects of TRP activity on metabolism in human myotubes were studied using radiolabeled glucose. FURA-2 was used for Ca2+ imaging. TRPA1, TRPM8 and TRPV1 were expressed at low levels in primary human myotubes and in m. gastrocnemius, m. soleus, and m. trapezius from rat. Activation of TRPA1 by ligustilide resulted in an increased glucose uptake and oxidation in human myotubes, whereas activation of TRPM8 by menthol and icilin significantly decreased glucose uptake and oxidation. Activation of heat sensing TRPV1 by capsaicin had no effect on glucose metabolism. Agonist-induced increases in intracellular Ca2+ levels by ligustilide and icilin in human myotubes confirmed a direct activation of TRPA1 and TRPM8, respectively. The mRNA expression of some genes involved in thermogenesis, i.e. peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), uncoupling protein (UCP) 1 and UCP3, were downregulated in human myotubes following TRPA1 activation, while the mRNA expression of TRPM8 and TRPA1 were downregulated following TRPM8 activation by menthol and icilin, respectively. Cold exposure (18 °C) of cultured myotubes followed by a short recovery period had no effect on glucose uptake and oxidation in the basal situation, however when TRPA1 and TRPM8 channels were chemically inhibited a temperature-induced difference in glucose metabolism was found. In conclusion, mRNA of TRPA1, TRPM8 and TRPV1 are expressed in rat skeletal muscle and human skeletal muscle cells. Modulation of TRPA1 and TRPM8 by chemical agents induced changes in Ca2+ levels and glucose metabolism in human skeletal muscle cells, indicating functional receptors.

A mix of ginger phenols exhibits anti‑adipogenic and lipolytic effects in mature adipocytes derived from 3T3‑L1 cells

The prevalence of obesity has increased rapidly worldwide. Obesity is characterized by excessive adipose tissue in the body, which is related to hyperplasia and hypertrophy in adipocytes. Ginger (Zingiber officinale Roscoe) is a medicinal plant that possesses an anti-obesogenic effect mostly attributed to gingerols, the most abundant bioactive compounds in ginger. The anti-adipogenic and lipolytic effects of these phenols have been shown when investigated individually. Therefore, the present study aimed to evaluate the lipolytic and anti-adipogenic activity of a mix of the main ginger phenols 6-gingerol, 8-gingerol, 10-gingerol, 6-shogaol, 8-shogaol and 10-shogaol on the 3T3-L1 cell line. A total of four study groups were designed: Negative control (3T3-L1 preadipocytes); positive control (mature 3T3-L1 adipocytes); phenols-pre (3T3-L1 cells stimulated with the phenols mix during adipogenic differentiation); and phenols-post (mature 3T3-L1 adipocytes stimulated with the phenols mix). MTT viability cell assay and Oil Red O staining were performed. Glycerol concentration supernatants were determined using the VITROS 350 Chemistry System. Expression of mRNA was measured using qPCR. The treatment with a 2 µg/ml ginger phenol dose reduced the lipid content by 45.52±7.8 and 35.95±0.76% in the phenols-pre and -post group, respectively, compared with that in the positive control group. The phenols-post group presented a higher glycerol concentration in the supernatant compared with that in the positive control and the phenols-pre groups. The mRNA expression levels of CCAAT/enhancer-binding protein alpha, peroxisome proliferator activated receptor-γ, fatty acid-binding protein 4 and fatty acid synthase were higher in the phenols-pre and lower in the phenols-post groups, compared with those in the positive control group. To the best of our knowledge, the current study demonstrated for the first time the anti-adipogenic and lipolytic effects of a mix of the main bioactive compounds found in ginger, and it also established the basis to use this mix of phenols in in vivo studies and clinical trials.

Thermogenic adipose tissue in energy regulation and metabolic health

The ability to generate thermogenic fat could be a targeted therapy to thwart obesity and improve metabolic health. Brown and beige adipocytes are two types of thermogenic fat cells that regulate energy balance. Both adipocytes share common morphological, biochemical, and thermogenic properties. Yet, recent evidence suggests unique features exist between brown and beige adipocytes, such as their cellular origin and thermogenic regulatory processes. Beige adipocytes also appear highly plastic, responding to environmental stimuli and interconverting between beige and white adipocyte states. Additionally, beige adipocytes appear to be metabolically heterogenic and have substrate specificity. Nevertheless, obese and aged individuals cannot develop beige adipocytes in response to thermogenic fat-inducers, creating a key clinical hurdle to their therapeutic promise. Thus, elucidating the underlying developmental, molecular, and functional mechanisms that govern thermogenic fat cells will improve our understanding of systemic energy regulation and strive for new targeted therapies to generate thermogenic fat. This review will examine the recent advances in thermogenic fat biogenesis, molecular regulation, and the potential mechanisms for their failure.

Spicy food consumption is associated with abdominal obesity among Chinese Han population aged 30-79 years in the Sichuan Basin: a population-based cross-sectional study

BACKGROUND

Few animal experiments and volunteer-based intervention studies have showed a controversial effect of spicy foods on abdominal obesity. We aimed to examine the association between spicy food frequency, spicy flavor, and abdominal obesity among Chinese Han population in the Sichuan Basin which area eating spicy foods relatively often.

METHODS

A cross-sectional analysis was conducted using the Sichuan Basin baseline data from the China Multi-Ethnic Cohort (CMEC) study, including data from electronic questionnaires, anthropometric measurements and blood sample collection. A total of 40,877 adults (22,503 females) aged 30-79 years were included in the final analysis. Multivariable logistic regression yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for abdominal obesity associated with the strength of spicy flavor and frequency of spicy food intake.

RESULTS

The prevalence of daily spicy food eating was 47.3% in males and 52.7% in females, the percentages of abdominal obesity were 52.3%, 48.8%, 51.6% and 55.5% in the spicy food intake subgroups of never, 1-2 days/week, 3-5 days/week and 6-7 days/week, respectively. Compared with males who never consumed spicy food, the adjusted ORs (95% CIs) in the 1-2 days/week, 3-5 days/week and 6-7 days/week subgroups were 1.21 (1.09, 1.34), 1.35 (1.21, 1.51), and 1.35 (1.25, 1.47), respectively (P_trend < 0.001). The corresponding odds ratios for females were 0.95 (0.87, 1.05), 1.14 (1.03, 1.26), and 1.25 (1.16, 1.35), respectively (P_trend < 0.001). Similarly, compared with no spicy flavor, the adjusted ORs (95% CIs) of mild, middle, and strong spicy strength for abdominal obesity in males were 1.27 (1.17, 1.38), 1.51 (1.37, 1.67), and 1.36 (1.11, 1.67) respectively (P_trend < 0.001). The corresponding odds ratios for females were 1.14 (1.06, 1.23), 1.27 (1.15, 1.40), and 1.32 (1.06, 1.65), respectively (P_trend < 0.001).

CONCLUSIONS

The data indicated that spicy food consumption was a risk factor for abdominal obesity among Chinese adult population in the Sichuan Basin. The results need to be approved by large cohort studies.

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.

Association of pepper intake with all-cause and specific cause mortality - A systematic review and meta-analysis

OBJECTIVE

To conduct a comprehensive systematic review and meta-analysis to compare mortality and other clinical outcomes associated with chili pepper (CP) consumption versus no/rare consumption of CP.

METHODS

A comprehensive search was performed using Ovid, Cochrane, Medline, EMBASE, and Scopus from inception till January 16, 2020. Observational studies and randomized controlled trials were included, while pediatric/animal studies, letters/case reports, reviews, abstracts, and book chapters were excluded. All-cause mortality was studied as the primary outcome. Cardiovascular mortality, cancer-related deaths and cerebrovascular accidents were studied as secondary outcomes.

RESULTS

From 4729 studies, four studies met the inclusion criteria. Random effects pooled analysis showed that all-cause mortality among CP consumers was lower, compared to rare/non-consumers, with a hazard ratio (HR) of 0.87 [95% CI: 0.85-0.90; p<0.0001; I 2=1%]. HR for cardiovascular mortality was 0.83 [95% CI: 0.74-0.95; p = 0.005, I 2=66%] and for cancer-related mortality as 0.92 [95% CI: 0.87-0.97; p = 0.001; I 2=0%]. However, the HR for CVA was 0.78 [95% CI: 0.56-1.09; p = 0.26; I2 =60%]. The mode and amount of CP consumption varied across the studies, and data were insufficient to design an optimal strategy guiding its intake.

CONCLUSION

Regular CP consumption was associated with significantly lower all-cause, cardiovascular, and cancer-related mortalities. However, based on current literature, it is difficult to derive a standardized approach to guide the optimal mode and amount of CP consumption. This warrants well-designed prospective studies to further investigate the potential health benefits of CP consumption.

Distribution of transient receptor potential vanilloid-1 channels in gastrointestinal tract of patients with morbid obesity

BACKGROUND

Transient receptor potential vanilloid-1 (TRPV1), a nonselective cation channel, is activated by capsaicin, a pungent ingredient of hot pepper. Previous studies have suggested a link between obesity and capsaicin-associated pathways, and activation of TRPV1 may provide an alternative approach for obesity treatment. However, data on the TRPV1 distribution in human gastric mucosa are limited, and the degree of TRPV1 distribution in the gastric and duodenal mucosal cells of obese people in comparison with normal-weight individuals is unknown.

AIM

To clarify gastric and duodenal mucosal expression of TRPV1 in humans and compare TRPV1 expression in obese and healthy individuals.

METHODS

Forty-six patients with a body mass index (BMI) of > 40 kg/m² and 20 patients with a BMI between 18-25 kg/m² were included. Simultaneous biopsies from the fundus, antrum, and duodenum tissues were obtained from subjects between the ages of 18 and 65 who underwent esophagogastroduodenoscopy. Age, sex, history of alcohol and cigarette consumption, and past medical history regarding chronic diseases and medications were accessed from patient charts and were analyzed accordingly. Evaluation with anti-TRPV1 antibody was performed separately according to cell types in the fundus, antrum, and duodenum tissues using an immunoreactivity score. Data were analyzed using SPSS 17.0.

RESULTS

TRPV1 expression was higher in the stomach than in the duodenum and was predominantly found in parietal and chief cells of the fundus and mucous and foveolar cells of the antrum. Unlike foveolar cells in the antrum, TRPV1 was relatively low in foveolar cells in the fundus (4.92 ± 0.49 vs 0.48 ± 0.16, P < 0.01, Mann-Whitney U test). Additionally, the mucous cells in the duodenum also had low levels of TRPV1 compared to mucous cells in the antrum (1.33 ± 0.31 vs 2.95 ± 0.46, P < 0.01, Mann-Whitney U test). TRPV1 expression levels of different cell types in the fundus, antrum, and duodenum tissues of the morbidly obese group were similar to those of the control group. Staining with TRPV1 in fundus chief cells and antrum and duodenum mucous cells was higher in patients aged ≥ 45 years than in patients < 45 years (3.03 ± 0.42, 4.37 ± 0.76, 2.28 ± 0.55 vs 1.9 ± 0.46, 1.58 ± 0.44, 0.37 ± 0.18, P = 0.03, P < 0.01, P < 0.01, respectively, Mann-Whitney U test). The mean staining levels of TRPV1 in duodenal mucous cells in patients with diabetes and hypertension were higher than those in patients without diabetes and hypertension (diabetes: 2.11 ± 0.67 vs 1.02 ± 0.34, P = 0.04; hypertension: 2.42 ± 0.75 vs 1.02 ± 0.33, P < 0.01 Mann-Whitney U test).

CONCLUSION

The expression of TRPV1 is unchanged in the gastroduodenal mucosa of morbidly obese patients demonstrating that drugs targeting TRPV1 may be effective in these patients.

Meta-analysis evaluating the impact of chili-pepper intake on all-cause and cardiovascular mortality: A systematic review

BACKGROUND

Dietetics today occupy a significant place in the field of research, helping to discover cardiovascular benefits of healthy diets and consumption of organic foods such as fruits, vegetables, legumes, nuts, and whole grains. One of the components of vegetable-based diet is chili pepper (CP) which has been found to affect all-cause mortality.

METHODS

MEDLINE, EMBASE, Scopus, EBSCO, and Cochrane (Wiley) Central Register of Controlled Trials were searched from inception till January 9, 2020, identifying all relevant studies using keywords and truncations. Studies were included if (1) they were observational or randomized in nature (2) included patients consuming CP and (3) evaluated direct comparison between regular and rarely/never CP consumption.

RESULTS

Our preliminary search yielded 6976 articles. Post exclusion and after full-text screening, four potential observational studies with a population of 570,762. Pooled analysis found reduced all-cause mortality in CP consumers compared to nonconsumers with a risk ratio (RR) of 0.75 [95% CI: 0.64-0.88; p = 0.0004; I 2 = 97%]. The RR for CVD, cancer related and CVA deaths were 0.74 [95% CI: 0.62-0.88; p = 0.0006, I 2 = 66%], 0.77 [95% CI: 0.71-0.84; p = 0.0001; I 2 = 49%] and 0.76 [95% CI: 0.36-1.60; p = 0.47; I2 = 93%], respectively.

CONCLUSION

Statistically significant results of our analysis put forward a rationale indicating an association between lower risk of all-cause, cardiovascular and cancer related deaths and CP consumption.

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.

Estimation of Dietary Capsaicinoid Exposure in Korea and Assessment of Its Health Effects

The consumption of capsaicinoids, the active components in chili peppers, has been associated with both positive and negative health effects, and the level of capsaicinoid exposure may be an important determinant. Dietary capsaicinoid exposure was estimated using a previously developed database for capsaicinoid content and a 24-h dietary recall dataset obtained from the Korea National Health and Nutrition Examination Survey. The estimated consumption level was evaluated to determine its potential effects on weight reduction and gastrointestinal distress. The estimated daily mean capsaicinoid intake was 3.25 mg (2.17 mg capsaicin), and most Koreans consumed 1–30 mg of capsaicinoids (0.67–20 mg capsaicin) in a day. No adverse effect of capsaicin consumption was reported other than abdominal pain. For long-term repeated consumption, 30 mg may be the maximum tolerable dose. However, the effects on body weight or energy balance were inconsistent in 4–12 week clinical studies conducted with various capsaicin doses (2–135 mg), which was likely due to the complex interplay between capsaicin dose, study length, and participant characteristics. Therefore, the capsaicin consumption of most Koreans was below the levels that may cause adverse effects. However, more long-term studies for the dose range of 2–20 mg are required to further characterize capsaicin’s health benefits in Koreans.

Brown Adipose Tissue and Its Role in Insulin and Glucose Homeostasis

The increased worldwide prevalence of obesity, insulin resistance, and their related metabolic complications have prompted the scientific world to search for new possibilities to combat obesity. Brown adipose tissue (BAT), due to its unique protein uncoupling protein 1 (UPC1) in the inner membrane of the mitochondria, has been acknowledged as a promising approach to increase energy expenditure. Activated brown adipocytes dissipate energy, resulting in heat production. In other words, BAT burns fat and increases the metabolic rate, promoting a negative energy balance. Moreover, BAT alleviates metabolic complications like dyslipidemia, impaired insulin secretion, and insulin resistance in type 2 diabetes. The aim of this review is to explore the role of BAT in total energy expenditure, as well as lipid and glucose homeostasis, and to discuss new possible activators of brown adipose tissue in humans to treat obesity and metabolic disorders.

A Systematic Review of the European Rapid Alert System for Food and Feed: Tendencies in Illegal Food Supplements for Weight Loss

Background: Slimming products represent a dynamically growing group of food supplements worldwide. The efficacy of safely usable natural ingredients is usually below consumers' expectations. Certain manufacturers add unauthorized or prohibited ingredients to weight loss supplements in order to increase their efficacy. Hence, many of these products are adulterated and may pose a risk to the consumers' health. Aims: The aim of our work was to give an overview on natural ingredients used in slimming products, to summarize the frequently used synthetic adulterants and also to assess the trends of adulterated and illegal food supplements in the European Union based on the warnings of the Rapid Alert System for Food and Feed (RASFF) in the time period of 1988-2019. Methods: Reports between 1988-2019 were extracted from the RASFF portal on January 1, 2020. Each entry was individually reviewed. Results: 2,559 records of food supplements with quality problems were identified in the RASFF, several of which [319 (12,5%)] were marketed to facilitate weight loss. 202 (63,3%) contained unapproved, synthetic drug ingredients. The major adulterant (113 of 319, 35.4%) was DNP (2,4-dinitrophenol), whereas sibutramine was the second most frequent adulterant agent (69 products, 21,6%) between 1988 and 2019. Conclusion: The number of approved medicines for the indication of weight loss is relatively low and their efficacy (and also that of the natural ingredients) is limited. Therefore, a significant number of weight loss supplements is adulterated to satisfy patients' expectations. Hence, these products may cause serious adverse effects in sensitive patients.

Exercise Training of Secreted Protein Acidic and Rich in Cysteine (Sparc) KO Mice Suggests That Exercise-Induced Muscle Phenotype Changes Are SPARC-Dependent

We previously identified secreted protein acidic and rich in cysteine (Sparc) as an exercise-induced gene in young and elderly individuals. Via this animal experiment, we aim to identify selected implications of SPARC mainly within the muscle in the contexts of exercise. Mice were divided into eight groups based on three variables (age, genotype and exercise): Old (O) or young (Y) × Sparc knock-out (KO) or wild-type (WT) × sedentary (Sed) or exercise (Ex). The exercised groups were trained for 12 weeks at the lactate threshold (LT) speed (including 4 weeks of adaptation period) and all mice were sacrificed afterwards. Body and selected tissues were weighed, and lactate levels in different conditions measured. Expression of skeletal muscle (SM) collagen type I alpha 1 chain (COL1A1) and mitochondrially encoded cytochrome c oxidase I (MT-CO1) in addition to SM strength (grip power) were also measured. Ageing increased the body and white adipose tissue (WAT) weights but decreased SM weight percentage (to body weight) and MT-CO1 expression (in WT). Exercise increased SM COL1A1 in WT mice and MT-CO1 expression, as well as weight percentage of the tibialis anterior muscle, and decreased WAT weight (trend). Compared to WT mice, Sparc KO mice had lower body, muscle and WAT weights, with a decrease in SM MT-CO1 and COL1A1 expression with no genotype effect on lactate levels in all our blood lactate measures. Sparc KO effects on body composition, adiposity and metabolic patterns are toward a reduced WAT and body weight, but with a negative metabolic and functional phenotype of SM. Whereas such negative effects on SM are worsened with ageing, they are relatively improved by exercise. Importantly, our data suggest that the exercise-induced changes in the SM phenotype, in terms of increased performance (metabolic, strength and development), including lactate-induced changes, are SPARC-dependent.

Sweet scent lactones activate hot capsaicin receptor, TRPV1

In this study, we investigated the activation of Transient receptor potential vanilloid subtype 1, TRPV1, by lactones, a representative flavor ingredient currently used for foods and beverages. As a result, we found that some lactones having C4 acyl chain length, γ-octalactone, δ-nonalactone and β-methyl-γ-octalactone, γ-undecalactone with C7 acyl chain length and δ-undecalactone with C6 acyl chain length activated TRPV1. TRPV1 is known as a non-selective cation channels that respond to a wide range of physical and chemical stimuli such as high temperature, protons, capsaicin and so on. Furthermore, it has been also demonstrated that activation of TRPV1 induced energy expenditure enhancement and thermogenesis, suppressed accumulation of visceral fat in mice and prevented non-alcoholic fatty acid liver. Thus, lactones that function as TRPV1 agonists are thought to be important candidates for decreasing the risks of developing a metabolic syndrome.

The effect of Capsaicinoids or Capsinoids in red pepper on thermogenesis in healthy adults: A systematic review and meta-analysis

The outcomes of the earlier trials are controversial concerning the effect of Capsaicinoids/Capsinoids on thermogenesis. We carried out this systematic review and meta-analysis to examine the effect of Capsaicinoids/Capsinoids on thermogenesis indices including resting metabolic rate (RMR) and respiratory quotient (RQ) in healthy adults. An electronic literature search was conducted between 1990 and 2019, using the following databases: PubMed, Web of Sciences, Scopus, Cochrane Central Register of Controlled Trials, and EMBASE. Placebo-controlled clinical trials were considered as eligible papers. Effect sizes were pooled using weighted mean difference (WMD), with a random-effects model. Of the 4,092 articles, 13 studies were included in the meta-analysis. Pooled effect sizes revealed that compared with placebo, Capsaicinoids/Capsinoids significantly increased RMR (WMD: 33.99 Kcal/day, 95% CI: 15.95, 52.03; I² : 0%, p = .94), energy expenditure, and fat oxidation. It also significantly lessened RQ (WMD: -0.01, 95% CI: -0.02, -0.01; I² : 5.4%, p = .39) and carbohydrate oxidation. Moreover, intervention in capsule form for longer duration had a more considerable influence on RMR than comparative groups. We observed moderate improvement in RMR, RQ, and fat oxidation following supplementation with Capsaicinoids/Capsinoids. However, further high-quality studies are required to clarify the thermogenic properties of Capsaicinoids/Capsinoids.

Effects of Nutrition/Diet on Brown Adipose Tissue in Humans: A Systematic Review and Meta-Analysis

BACKGROUND

Brown adipose tissue (BAT) provides a minor contribution to diet-induced thermogenesis (DIT)-the metabolic response to food consumption. Increased BAT activity is generally considered beneficial for mammalian metabolism and has been associated with favorable health outcomes. The aim of the current systematic review was to explore whether nutritional factors and/or diet affect human BAT activity.

METHODS

We searched PubMed Central, Embase and Cochrane Library (trials) to conduct this systematic review (PROSPERO protocol: CRD42018082323).

RESULTS

We included 24 eligible papers that studied a total of 2785 participants. We found no mean differences in standardized uptake value of BAT following a single meal or after 6 weeks of L-Arginine supplementation. Resting energy expenditure (REE), however, was increased following a single meal and after supplementation of capsinoid and catechin when compared to a control condition (Z = 2.41, p = 0.02; mean difference = 102.47 (95% CI = 19.28-185.67)).

CONCLUSIONS

Human BAT activity was not significantly affected by nutrition/diet. Moreover, REE was only increased in response to a single meal, but it is unlikely that this was due to increased BAT activity. BAT activity assessments in response to the chronic effect of food should be considered along with other factors such as body composition and/or environmental temperature.

An Examination of a Novel Weight Loss Supplement on Anthropometry and Indices of Cardiovascular Disease Risk

PURPOSE

This study examined whether adding Dichrostachys glomerata (DG; 300 mg/d) to thermogenic supplements with (DG + C) and without (DG) caffeine and other nutrients affects weight loss, changes in body composition, and/or markers of health.

METHODS

Sixty-eight participants (female, 54%) were grouped in a double-blind, parallel, stratified random, placebo-controlled manner to supplement their diet with a placebo, DG, or DG + C for 12 weeks while maintaining their normal diet and physical activity. Diet, physical activity, body weight, body composition, anthropometric measures, resting energy expenditure, fasting blood samples, and questionnaires were obtained at 0, 4, 8, and 12 weeks and analyzed using general linear models with repeated measures. Data are reported as mean (±SD) and change from baseline (mean, 95% confidence interval) for weeks 4, 8, and 12, respectively, with p values showing changes from baseline.

RESULTS

DG treatment promoted significant but minor reductions in fat mass (-0.56 [-1.02, -0.14], p = 0.01; -0.63 [-1.23, -0.02], p = 0.04; -0.71 [-1.47, 0.09] kg, p = 0.08) and percent body fat (-0.46 [-0.96, -0.04], p = 0.07; -0.63 [-1.16, -0.10], p = 0.02; -0.78 [-1.45, 0.07] %, p = 0.03). There was some evidence that DG + C increased resting energy expenditure, decreased hunger, increased satiety, and improved sleep quality (diminished in DG + C). No other significant effects were observed.

CONCLUSIONS

Ingestion of thermogenic supplements containing DG (300 mg/d) with and without caffeine and other nutrients in overweight but otherwise healthy participants who did not alter diet or physical activity promoted clinically insignificant changes in body weight and composition.

Translational Pharmacology and Physiology of Brown Adipose Tissue in Human Disease and Treatment

Human brown adipose tissue (BAT) is experimentally modeled to better understand the biology of this important metabolic tissue, and also to enable the potential discovery and development of novel therapeutics for obesity and sequelae resulting from the persistent positive energy balance. This chapter focuses on translation into humans of findings and hypotheses generated in nonhuman models of BAT pharmacology. Given the demonstrated challenges of sustainably reducing caloric intake in modern humans, potential solutions to obesity likely lie in increasing energy expenditure. The energy-transforming activities of a single cell in any given tissue can be conceptualized as a flow of chemical energy from energy-rich substrate molecules into energy-expending, endergonic biological work processes through oxidative degradation of organic molecules ingested as nutrients. Despite the relatively tight coupling between metabolic reactions and products, some expended energy is incidentally lost as heat, and in this manner a significant fraction of the energy originally captured from the environment nonproductively transforms into heat rather than into biological work. In human and other mammalian cells, some processes are even completely uncoupled, and therefore purely energy consuming. These molecular and cellular actions sum up at the physiological level to adaptive thermogenesis, the endogenous physiology in which energy is nonproductively released as heat through uncoupling of mitochondria in brown fat and potentially skeletal muscle. Adaptive thermogenesis in mammals occurs in three forms, mostly in skeletal muscle and brown fat: shivering thermogenesis in skeletal muscle, non-shivering thermogenesis in brown fat, and diet-induced thermogenesis in brown fat. At the cellular level, the greatest energy transformations in humans and other eukaryotes occur in the mitochondria, where creating energetic inefficiency by uncoupling the conversion of energy-rich substrate molecules into ATP usable by all three major forms of biological work occurs by two primary means. Basal uncoupling occurs as a passive, general, nonspecific leak down the proton concentration gradient across the membrane in all mitochondria in the human body, a gradient driving a key step in ATP synthesis. Inducible uncoupling, which is the active conduction of protons across gradients through processes catalyzed by proteins, occurs only in select cell types including BAT. Experiments in rodents revealed UCP1 as the primary mammalian molecule accounting for the regulated, inducible uncoupling of BAT, and responsive to both cold and pharmacological stimulation. Cold stimulation of BAT has convincingly translated into humans, and older clinical observations with nonselective 2,4-DNP validate that human BAT's participation in pharmacologically mediated, though nonselective, mitochondrial membrane decoupling can provide increased energy expenditure and corresponding body weight loss. In recent times, however, neither beta-adrenergic antagonism nor unselective sympathomimetic agonism by ephedrine and sibutramine provide convincing evidence that more BAT-selective mechanisms can impact energy balance and subsequently body weight. Although BAT activity correlates with leanness, hypothesis-driven selective β3-adrenergic agonism to activate BAT in humans has only provided robust proof of pharmacologic activation of β-adrenergic receptor signaling, limited proof of the mechanism of increased adaptive thermogenesis, and no convincing evidence that body weight loss through negative energy balance upon BAT activation can be accomplished outside of rodents. None of the five demonstrably β3 selective molecules with sufficient clinical experience to merit review provided significant weight loss in clinical trials (BRL 26830A, TAK 677, L-796568, CL 316,243, and BRL 35135). Broader conclusions regarding the human BAT therapeutic hypothesis are limited by the absence of data from most studies demonstrating specific activation of BAT thermogenesis in most studies. Additionally, more limited data sets with older or less selective β3 agonists also did not provide strong evidence of body weight effects. Encouragingly, β3-adrenergic agonists, catechins, capsinoids, and nutritional extracts, even without robust negative energy balance outcomes, all demonstrated increased total energy expenditure that in some cases could be associated with concomitant activation of BAT, though the absence of body weight loss indicates that in no cases did the magnitude of negative energy balance reach sufficient levels. Glucocorticoid receptor agonists, PPARg agonists, and thyroid hormone receptor agonists all possess defined molecular and cellular pharmacology that preclinical models predicted to be efficacious for negative energy balance and body weight loss, yet their effects on human BAT thermogenesis upon translation were inconsistent with predictions and disappointing. A few new mechanisms are nearing the stage of clinical trials and may yet provide a more quantitatively robust translation from preclinical to human experience with BAT. In conclusion, translation into humans has been demonstrated with BAT molecular pharmacology and cell biology, as well as with physiological response to cold. However, despite pharmacologically mediated, statistically significant elevation in total energy expenditure, translation into biologically meaningful negative energy balance was not achieved, as indicated by the absence of measurable loss of body weight over the duration of a clinical study.

Properties of capsaicin and its utility in veterinary and human medicine

The main aim of this paper was to show the variety of capsaicin's properties. Capsaicin is an active component of plants of the Capsicum genus, and is known for its pungency. Capsaicin is used in the food, pharmaceutical and cosmetic industries. Additional properties of capsaicin have been demonstrated, including pain relief, weight loss, body thermoregulation, and antioxidant, antimicrobial and anticancer activities. Studies of capsaicin's effects on the human and animal organism need to be continued, with special emphasis on new applications.

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.

Capsaicinoids supplementation decreases percent body fat and fat mass: adjustment using covariates in a post hoc analysis

BACKGROUND

Capsaicinoids (CAPs) found in chili peppers and pepper extracts, are responsible for enhanced metabolism. The objective of the study was to evaluate the effects of CAPs on body fat and fat mass while considering interactions with body habitus, diet and metabolic propensity.

METHODS

Seventy-five (N = 75) volunteer (male and female, age: 18 and 56 years) healthy subjects were recruited. This is a parallel group, randomized, double-blind, placebo controlled exploratory study. Subjects were randomly assigned to receive either placebo, 2 mg CAPs or 4 mg CAPs dosing for 12 weeks. After initial screening, subjects were evaluated with respect to fat mass and percent body fat at baseline and immediately following a 12-week treatment period. The current study evaluates two measures of fat loss while considering six baseline variables related to fat loss. Baseline measurements of importance in this paper are those used to evaluate body habitus, diet, and metabolic propensity. Lean mass and fat mass (body habitus); protein intake, fat intake and carbohydrate intake; and total serum cholesterol level (metabolic propensity) were assessed. Body fat and fat mass were respectively re-expressed as percent change in body fat and change in fat mass by application of formula outcome = (12-week value - baseline value) / baseline value) × 100. Thus, percent change in body fat and change in fat mass served as dependent variables in the evaluation of CAPs. Inferential statistical tests were derived from the model to compare low dose CAPs to placebo and high dose CAPs to placebo.

RESULTS

Percent change in body fat after 12 weeks of treatment was 5.91 percentage units lower in CAPs 4 mg subjects than placebo subjects after adjustment for covariates (p = 0.0402). Percent change in fat mass after 12 weeks of treatment was 6.68 percentage units lower in Caps 4 mg subjects than placebo subjects after adjustment for covariates (p = 0.0487).

CONCLUSION

These results suggest potential benefits of Capsaicinoids (CAPs) on body fat and fat mass in post hoc analysis. Further studies are required to explore pharmacological, physiological, and metabolic benefits of both chronic and acute Capsaicinoids consumption.

TRIAL REGISTRATION

ISRCTN10458693 'retrospectively registered'.

Relationship between spicy flavor, spicy food intake frequency, and general obesity in a rural adult Chinese population: The RuralDiab study

BACKGROUND AND AIMS

The purpose of this study was to explore the association between spicy flavor, spicy food frequency, and general obesity in Chinese rural adults.

METHODS AND RESULTS

A total of 15,683 subjects (5907 males, 9776 females) aged 35-74 years from the RuralDiab Study were recruited for this cross-sectional study. Analysis of covariance was used to determine the differences of participant characteristics across body mass index (BMI) categories. Logistic regression yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for obesity associated with the level of spicy flavor and frequency of spicy food intake. A meta-analysis was conducted to validate the result of the cross-sectional study. The crude and standardized prevalence of obesity were 16.78% and 17.57%, respectively. Compared with No spicy flavor, the adjusted ORs (95% CIs) of Mild, Middle, and Heavy spicy flavor for obesity were 1.232 (1.117-1.359), 1.463 (1.290-1.659), and 1.591 (1.293-1.958), respectively (P_trend < 0.001). Similarly, compared with no spicy food consumption, the adjusted ORs (95% CIs) of 1 or 2 days/week, 3-5 days/week, and 6 or 7 days/week were 1.097 (0.735-1.639), 1.294 (0.932-1.796), and 1.250 (1.025-1.525), respectively (P_trend = 0.026). The point estimate and 95% CI of mean BMI difference between the spicy food consuming group and spicy food non-consuming group was 0.37 (95% CI: 0.30-0.44) in the meta-analysis.

CONCLUSION

The data indicated that spicy flavor and spicy food frequency were positively associated with general obesity in Chinese rural populations.

Beneficial Effects of Kimchi, a Korean Fermented Vegetable Food, on Pathophysiological Factors Related to Atherosclerosis

Atherosclerosis is a progressive disease that is characterized by accumulation of lipids and fibrous elements in large arteries. Its etiology is involved with pathophysiological factors such as lipoprotein oxidation, inflammation, and dyslipidemia. Kimchi is a Korean fermented vegetable side dish made with vegetables and kimchi condiments. To date, numerous in vitro, in vivo, and human studies have cited the health benefits of kimchi. 3-(4'-Hydroxyl-3',5'-dimethoxyphenyl)propionic acid is one of the active compounds of kimchi, and its antioxidant and anti-atherosclerosclerotic effects have been reported. This review presents the laboratory and clinical evidence of the anti-atherosclerotic effects of kimchi based on its lipid-lowering, antioxidant, and anti-inflammatory activities.

Ingested capsaicinoids can prevent low-fat-high-carbohydrate diet and high-fat diet-induced obesity by regulating the NADPH oxidase and Nrf2 pathways

Objective

Capsaicinoids (CAPs), most commonly found in chili peppers, have a multitude of pharmacological and physiological effects, such as anti-inflammation, antioxidant, and anticancer effects. In the present study, we set out to investigate the hypothesis that CAPs mitigate obesity in rats and the possible mechanisms thereof.

Materials and methods

Rats were divided into six groups, including control (±10 mg CAPs/kg body weight [BW]), low-fat–high-sucrose diet (±10 mg CAPs/kg BW), and high-fat diet (±10 mg CAPs/kg BW). Blood samples and liver and aortic tissues were taken at the end of the study.

Results

CAPs supplementation significantly reduced hyperglycemia and hyperlipidemia (P<0.001) and ameliorated oxidative damage by reducing malondialdehyde concentrations in serum and liver and by increasing total antioxidant capacity in serum induced by the low-fat–high-sucrose and high-fat diets (P<0.001 for all). CAPs also depressed levels of NFκB p65, gp91^phox, and p22^phox, essential components of NADPH oxidase, in the aorta of rats. However, levels of Nrf2, Sirt1, and endothelial nitric oxide synthase were significantly increased in the aorta.

Conclusion

CAPs may at least partially reduce adverse effects due to high-fat diet and sucrose consumption through regulation of energy metabolism, oxidative stress, and proteins involved in vasoprotection.

The Combined Effects of Exercise, Diet, and a Multi-Ingredient Dietary Supplement on Body Composition and Adipokine Changes in Overweight Adults

BACKGROUND

Very few weight and fat loss supplements undergo finished-product research to examine efficacy. The purpose of this study was to determine the effects of an 8-week diet and exercise program on body composition, hip and waist girth, and adipokines and evaluate whether a dietary supplement containing raspberry ketone, capsaicin, caffeine, garlic, and Citrus aurantium enhanced outcomes.

METHODS

Overweight men and women completed this randomized, placebo-controlled, double-blind study. Participants consumed 4 capsules/d of supplement (EXP; n = 18) or placebo (PLA; n = 18). Participants underwent 8 weeks of daily supplementation, calorie restriction (500 kcal < RMR [resting metabolic rate] × 1.2), and supervised progressive exercise training 3 times a week. Body composition, girth, and adipokines were assessed at baseline and postintervention (T1 and T2).

RESULTS

Significant decreases in weight (-2.6 ± 0.57 kg, p < 0.001), fat mass (-1.8 ± 0.20 kg; p < 0.001), and percentage body fat (-3.7% ± 0.29%, p < 0.001) and a significant increase in lean body mass (LBM; 1.5 ± 0.26 kg; p < 0.001) were seen from T1 to T2 in both groups. For men, only those in the EXP group increased LBM from T1 to T2 (1.3 ± 0.38 kg; p < 0.05). Hip girth was also reduced, with the women in the EXP group (-10.7 ± 2.15 cm, p < 0.001) having a greater reduction. There was a time by group interaction, with significant decreases in leptin (p < 0.001) and significant increases in adiponectin (p < 0.05) in the EXP group.

CONCLUSIONS

Significant improvements in adipokines and leptin support the utility of exercise, diet, and fat loss for impacting inflammatory biomarkers. The improvement in adiponectin with EXP may suggest a unique health mechanism.

Association between spicy food consumption and lipid profiles in adults: a nationwide population-based study

CVD remains the leading cause of mortality worldwide, with abnormal lipid metabolism as a major risk factor. The aim of this study was to investigate associations between spicy food consumption and serum lipids in Chinese adults. Data were extracted from the 2009 phase of the China Health and Nutrition Survey, consisting of 6774 apparently healthy Chinese adults aged 18-65 years. The frequency of consumption and degree of pungency of spicy food were self-reported, and regular spicy food consumption was assessed using three consecutive 24-h recalls. Total cholesterol, TAG, LDL-cholesterol and HDL-cholesterol in fasting serum were measured. Multilevel mixed-effects models were constructed to estimate associations between spicy food consumption and serum lipid profiles. The results showed that the frequency and the average amount of spicy food intake were both inversely associated with LDL-cholesterol and LDL-cholesterol:HDL-cholesterol ratio (all P for trend<0·05) after adjustment for potential confounders and cluster effects. HDL-cholesterol in participants who usually consumed spicy food (≥5 times/week) and who consumed spicy food perceived as moderate in pungency were significantly higher than those who did not (both P<0·01). The frequency and the average amount of spicy food intake and the degree of pungency in spicy food were positively associated with TAG (all P for trend<0·05). Spicy food consumption was inversely associated with serum cholesterol and positively associated with serum TAG, and additional studies are needed to confirm the findings as well as to elucidate the potential roles of spicy food consumption in lipid metabolism.

Nutrition Supplements to Stimulate Lipolysis: A Review in Relation to Endurance Exercise Capacity

Athletes make great efforts to increase their endurance capacity in many ways. Using nutrition supplements for stimulating lipolysis is one such strategy to improve endurance performance. These supplements contain certain ingredients that affect fat metabolism; furthermore, in combination with endurance training, they tend to have additive effects. A large body of scientific evidence shows that nutrition supplements increase fat metabolism; however, the usefulness of lipolytic supplements as ergogenic functional foods remains controversial. The present review will describe the effectiveness of lipolytic supplements in fat metabolism and as an ergogenic aid for increasing endurance exercise capacity. There are a number of lipolytic supplements available on the market, but this review focuses on natural ingredients such as caffeine, green tea extract, L-carnitine, Garcinia cambogia (hydroxycitric acid), capsaicin, ginseng, taurine, silk peptides and octacosanol, all of which have shown scientific evidence of enhancing fat metabolism associated with improving endurance performance. We excluded some other supplements owing to lack of data on fat metabolism or endurance capacity. Based on the data in this review, we suggest that a caffeine and green tea extract improves endurance performance and enhances fat oxidation. Regarding other supplements, the data on their practical implications needs to be gathered, especially for athletes.

Chili pepper as a body weight-loss food

Chili has culinary as well as medical importance. Studies in humans, using a wide range of doses of chili intake (varying from a single meal to a continuous uptake for up to 12 weeks), concluded that it facilitates weight loss. In regard to this, the main targets of chili are fat metabolism, energy expenditure, and thermogenesis. To induce weight loss, the active substance of chili, capsaicin, activates Transient Receptor Potential Cation Channel sub-family V member 1 (TRPV1) channels) receptors causing an increase in intracellular calcium levels and triggering the sympathetic nervous system. Apart from TRPV1, chili directly reduces energy expenditure by activating Brown Adipose Tissue. Weight loss by chili is also the result of an improved control of insulin, which supports weight management and has positive effects for treatment for diseases like obesity, diabetes and cardiovascular disorders. This review summarizes the major pathways by which chili contributes to ameliorating parameters that help weight management and how the consumption of chili can help in accelerating weight loss through dietary modifications.

TRP Channels as Therapeutic Targets in Diabetes and Obesity

During the last three to four decades the prevalence of obesity and diabetes mellitus has greatly increased worldwide, including in the United States. Both the short- and long-term forecasts predict serious consequences for the near future, and encourage the development of solutions for the prevention and management of obesity and diabetes mellitus. Transient receptor potential (TRP) channels were identified in tissues and organs important for the control of whole body metabolism. A variety of TRP channels has been shown to play a role in the regulation of hormone release, energy expenditure, pancreatic function, and neurotransmitter release in control, obese and/or diabetic conditions. Moreover, dietary supplementation of natural ligands of TRP channels has been shown to have potential beneficial effects in obese and diabetic conditions. These findings raised the interest and likelihood for potential drug development. In this mini-review, we discuss possibilities for better management of obesity and diabetes mellitus based on TRP-dependent mechanisms.

Harnessing the Therapeutic Potential of Capsaicin and Its Analogues in Pain and Other Diseases

Capsaicin is the most predominant and naturally occurring alkamide found in Capsicum fruits. Since its discovery in the 19th century, the therapeutic roles of capsaicin have been well characterized. The potential applications of capsaicin range from food flavorings to therapeutics. Indeed, capsaicin and few of its analogues have featured in clinical research covered by more than a thousand patents. Previous records suggest pleiotropic pharmacological activities of capsaicin such as an analgesic, anti-obesity, anti-pruritic, anti-inflammatory, anti-apoptotic, anti-cancer, anti-oxidant, and neuro-protective functions. Moreover, emerging data indicate its clinical significance in treating vascular-related diseases, metabolic syndrome, and gastro-protective effects. The dearth of potent drugs for management of such disorders necessitates the urge for further research into the pharmacological aspects of capsaicin. This review summarizes the historical background, source, structure and analogues of capsaicin, and capsaicin-triggered TRPV1 signaling and desensitization processes. In particular, we will focus on the therapeutic roles of capsaicin and its analogues in both normal and pathophysiological conditions.

MECHANISMS IN ENDOCRINOLOGY: Brown adipose tissue in humans: regulation and metabolic significance

The recent discovery that functional brown adipose tissue (BAT) persists in adult humans has enkindled a renaissance in metabolic research, with a view of harnessing its thermogenic capacity to combat obesity. This review focuses on the advances in the regulation and the metabolic significance of BAT in humans. BAT activity in humans is stimulated by cold exposure and by several factors such as diet and metabolic hormones. BAT function is regulated at two levels: an acute process involving the stimulation of the intrinsic thermogenic activity of brown adipocytes and a chronic process of growth involving the proliferation of pre-existing brown adipocytes or differentiation to brown adipocytes of adipocytes from specific white adipose tissue depots. BAT activity is reduced in the obese, and its stimulation by cold exposure increases insulin sensitivity and reduces body fat. These observations provide strong evidence that BAT plays a significant role in energy balance in humans and has the potential to be harnessed as a therapeutic target for the management of obesity.

Obesity Phytotherapy

Obesity is an important disorders due to which 25 million deaths occur annually worldwide. Synthetic drugs for weight loss have low efficacy and high side effects. Apart from synthetic drugs in modern medicine, various other methods including the use of herbal medications are used to induce weight loss. Cambodia hoodia, green tea, Citrus aurantium, white beans, fenugreek, caffeine, ephedrine, capsaicin, yohimbine, chitosan, fitostreols, and guar gum have been studied in clinical trials and their effects have been confirmed. It seems necessary to study more to determine the effectiveness and safety of medicinal plants and herbal extracts as well as pharmaceutically active ingredients that may have the property of weight loss. In this article, we aimed to review recent knowledge about medicinal plants that are recommended for weight loss.

Capsaicinoids Modulating Cardiometabolic Syndrome Risk Factors: Current Perspectives

Capsaicinoids are bioactive nutrients present within red hot peppers reported to cut ad libitum food intake, to increase energy expenditure (thermogenesis) and lipolysis, and to result in weight loss over time. In addition it has shown more benefits such as improvement in reducing oxidative stress and inflammation, improving vascular health, improving endothelial function, lowering blood pressure, reducing endothelial cytokines, cholesterol lowering effects, reducing blood glucose, improving insulin sensitivity, and reducing inflammatory risk factors. All these beneficial effects together help to modulate cardiometabolic syndrome risk factors. The early identification of cardiometabolic risk factors can help try to prevent obesity, hypertension, diabetes, and cardiovascular disease.

Dietary Capsaicin Protects Cardiometabolic Organs from Dysfunction

Chili peppers have a long history of use for flavoring, coloring, and preserving food, as well as for medical purposes. The increased use of chili peppers in food is very popular worldwide. Capsaicin is the major pungent bioactivator in chili peppers. The beneficial effects of capsaicin on cardiovascular function and metabolic regulation have been validated in experimental and population studies. The receptor for capsaicin is called the transient receptor potential vanilloid subtype 1 (TRPV1). TRPV1 is ubiquitously distributed in the brain, sensory nerves, dorsal root ganglia, bladder, gut, and blood vessels. Activation of TRPV1 leads to increased intracellular calcium signaling and, subsequently, various physiological effects. TRPV1 is well known for its prominent roles in inflammation, oxidation stress, and pain sensation. Recently, TRPV1 was found to play critical roles in cardiovascular function and metabolic homeostasis. Experimental studies demonstrated that activation of TRPV1 by capsaicin could ameliorate obesity, diabetes, and hypertension. Additionally, TRPV1 activation preserved the function of cardiometabolic organs. Furthermore, population studies also confirmed the beneficial effects of capsaicin on human health. The habitual consumption of spicy foods was inversely associated with both total and certain causes of specific mortality after adjustment for other known or potential risk factors. The enjoyment of spicy flavors in food was associated with a lower prevalence of obesity, type 2 diabetes, and cardiovascular diseases. These results suggest that capsaicin and TRPV1 may be potential targets for the management of cardiometabolic vascular diseases and their related target organs dysfunction.

Tolerability of Capsaicinoids from Capsicum Extract in a Beadlet Form: A Pilot Study

A single center, open-label, dose-finding adaptive study was conducted in twelve healthy overweight female subjects. The study was to evaluate the safety and tolerability of the capsaicinoids (CAPs) from Capsicum extract in a beadlet form compared to placebo in a healthy overweight population. The investigational product capsaicinoids (CAPs) from Capsicum extract in a beadlet form (Capsimax®) a proprietary encapsulated form of Capsicum extract in beadlet form supplemented at 2 mg, 4 mg, 6 mg, 8 mg and 10 mg of CAPs. An ascending dose protocol evaluated a total dose of 10 mg daily given in five divided doses (2 mg, 4 mg, 6 mg, 8 mg and 10 mg of CAPs). Each dose was given for a week. Safety and tolerability were assessed. Primary outcomes were tolerability assessments and reports of adverse events. Tolerability assessments were observed on skin color and any changes in skin, bowel movement, digestion, mouth or throat, hair color or changes in hair color, urination includes frequency and burning sensations, breathing, any changes in their health. Secondary outcomes were body weight, body mass index (BMI), blood pressure (SBP/DBP), vital signs, electrocardiograms, clinical chemistry parameters including liver function tests, lung function tests and kidney function tests and complete blood count (CBC). No dose effective changes were observed. The escalating dose levels of CAPs in a beadlet form product found was tolerable and safe for weight management studies. Tolerability assessments and safety blood markers showed no significant changes from baseline. No significant serious adverse events were reported throughout the duration of the study. Further longer term studies are required to explore the tolerability of the product. This trial is registered with ISRCTN: #  ISRCTN10975080.

Effects of TRP channel agonist ingestion on metabolism and autonomic nervous system in a randomized clinical trial of healthy subjects

Various lines of published evidence have already demonstrated the impact of TRPV1 agonists on energetic metabolism through the stimulation of the sympathetic nervous system (SNS). This study presents a trial investigating if stimulation of the two related sensory receptors TRPA1 and TRPM8 could also stimulate the SNS and impact the energetic metabolism of healthy subjects. The trial was designed to be double-blinded, randomized, cross-over, placebo-controlled with healthy subjects and the impact on the energetic metabolism and the autonomic nervous system (ANS) of cinnamaldehyde, capsaicin and a cooling flavor was measured during the 90 min after ingestion. Energy expenditure and substrate oxidation were measured by indirect calorimetry. An exploratory method to measure ANS activity was by facial thermography and power spectral analysis of heart rate variability using ECG was also used. Following cinnamaldehyde ingestion, energy expenditure was increased as compared to placebo. Furthermore, postprandial fat oxidation was maintained higher compared to placebo after cinnamaldehyde and capsaicin ingestion. Similar peripheral thermoregulation was observed after capsaicin and cinnamaldehyde ingestion. Unlike capsaicin, the dose of cinnamaldehyde was not judged to be sensorially ‘too intense’ by participants suggesting that Cinnamaldehyde would be a more tolerable solution to improve thermogenesis via spicy ingredients as compared to capsaicin.

Capsaicin and Related Food Ingredients Reducing Body Fat Through the Activation of TRP and Brown Fat Thermogenesis

Brown adipose tissue (BAT) is a site of sympathetically activated adaptive nonshivering thermogenesis, thereby being involved in the regulation of energy balance and body fatness. Recent radionuclide imaging studies have revealed the existence of metabolically active BAT in adult humans. Human BAT is activated by acute cold exposure and contributes to cold-induced increase in whole-body energy expenditure. The metabolic activity of BAT is lower in older and obese individuals. The inverse relationship between the BAT activity and body fatness suggests that BAT, because of its energy dissipating activity, is protective against body fat accumulation. In fact, repeated cold exposure recruits BAT in association with increased energy expenditure and decreased body fatness. The stimulatory effects of cold are mediated through the activation of transient receptor potential (TRP) channels, most of which are also chemesthetic receptors for various naturally occurring substances including herbal plants and food ingredients. Capsaicin and its analog capsinoids, representative agonists of TRPV1, mimic the effects of cold to decrease body fatness through the activation and recruitment of BAT. The well-known antiobesity effect of green tea catechins is also attributable to the activation of the sympathetic nerve and BAT system. Thus, BAT is a promising target for combating obesity and related metabolic disorders in humans.

The metabolic effects of a commercially available chicken peri-peri (African bird's eye chilli) meal in overweight individuals

A growing body of evidence suggests that capsaicin ingestion may lead to desirable metabolic outcomes; however, the results in humans are equivocal. Whether or not benefits may be gained from ingestion of capsaicin via a commercially available meal has not been determined. The objectives of this randomised, cross-over intervention study were to compare the 2 h postprandial effects of a standard commercially prepared meal containing chilli (HOT, 5·82 mg total capsaicinoids) with a similar meal with no chilli (CON, 25 kg/m2 and a waist circumference >94 cm (men) or 80 cm (women), were studied. Participants had normal glucose tolerance and were accustomed, but were not regular chilli eaters. A paired t test indicated that insulin AUC was smaller following the HOT meal (P=0·002). Similarly, there was a tendency for glucose AUC to be reduced following the HOT meal (P=0·056). No discernable effects of the HOT meal were observed on metabolic rate, core temperature, hs-CRP concentrations and endothelial-dependent microvascular reactivity. The results from this study indicate that a standard restaurant meal containing a relatively small dose of capsaicin delivered via African bird's eye chilli, which is currently available to the public, results in lower postprandial insulin concentrations in overweight individuals, compared with the same meal without chilli.

Performance Enhancing Diets and the PRISE Protocol to Optimize Athletic Performance

The training regimens of modern-day athletes have evolved from the sole emphasis on a single fitness component (e.g., endurance athlete or resistance/strength athlete) to an integrative, multimode approach encompassing all four of the major fitness components: resistance (R), interval sprints (I), stretching (S), and endurance (E) training. Athletes rarely, if ever, focus their training on only one mode of exercise but instead routinely engage in a multimode training program. In addition, timed-daily protein (P) intake has become a hallmark for all athletes. Recent studies, including from our laboratory, have validated the effectiveness of this multimode paradigm (RISE) and protein-feeding regimen, which we have collectively termed PRISE. Unfortunately, sports nutrition recommendations and guidelines have lagged behind the PRISE integrative nutrition and training model and therefore limit an athletes' ability to succeed. Thus, it is the purpose of this review to provide a clearly defined roadmap linking specific performance enhancing diets (PEDs) with each PRISE component to facilitate optimal nourishment and ultimately optimal athletic performance.

Activation of TRPV1 channel by dietary capsaicin improves visceral fat remodeling through connexin43-mediated Ca2+ influx

Background

The prevalence of obesity has dramatically increased worldwide and has attracted rising attention, but the mechanism is still unclear. Previous studies revealed that transient receptor potential vanilloid 1 (TRPV1) channels take part in weight loss by enhancing intracellular Ca²⁺ levels. However, the potential mechanism of the effect of dietary capsaicin on obesity is not completely understood. Ca²⁺ transfer induced by connexin43 (Cx43) molecules between coupled cells takes part in adipocyte differentiation. Whether TRPV1-evoked alterations in Cx43-mediated adipocyte-to-adipocyte communication play a role in obesity is unknown.

Materials and methods

We investigated whether Cx43 participated in TRPV1-mediated adipocyte lipolysis in cultured 3T3-L1 preadipocytes and visceral adipose tissues from humans and wild-type (WT) and TRPV1-deficient (TRPV1^-/-) mice.

Results

TRPV1 and Cx43 co-expressed in mesenteric adipose tissue. TRPV1 activation by capsaicin increased the influx of Ca²⁺ in 3T3-L1 preadipocytes and promoted cell lipolysis, as shown by Oil-red O staining. These effects were deficient when capsazepine, a TRPV1 antagonist, and 18 alpha-glycyrrhetinic acid (18α-GA), a gap-junction inhibitor, were administered. Long-term chronic dietary capsaicin reduced the weights of perirenal, mesenteric and testicular adipose tissues in WT mice fed a high-fat diet. Capsaicin increased the expression levels of p-CaM, Cx43, CaMKII, PPARδ and HSL in mesenteric adipose tissues from WT mice fed a high-fat diet, db/db mice, as well as obese humans, but these effects of capsaicin were absent in TRPV1^-/- mice. Long-term chronic dietary capsaicin decreased the body weights and serum lipids of WT mice, but not TRPV1^-/- mice, fed a high-fat diet.

Conclusion

This study demonstrated that capsaicin activation of TRPV1-evoked increased Ca²⁺ influx in Cx43-mediated adipocyte-to-adipocyte communication promotes lipolysis in both vitro and vivo. TRPV1 activation by dietary capsaicin improves visceral fat remodeling through the up-regulation of Cx43.