Capsaicinoids Modulating Cardiometabolic Syndrome Risk Factors: Current Perspectives

Suppression of the postprandial hyperglycemia in patients with type 2 diabetes by a raw medicinal herb powder is weakened when consumed in ordinary hard gelatin capsules: A randomized crossover clinical trial

INTRODUCTION

Contradictory claims about the efficacy of several medicinal plants to promote glycemic control in patients with type 2 diabetes mellitus (T2DM) have been explained by divergences in the administration form and by extrapolation of data obtained from healthy individuals. It is not known whether the antidiabetic effects of traditional herbal medicines are influenced by gelatin capsules. This randomized crossover trial aimed to evaluate the acute effect of a single dose of raw cinnamon consumed orally either dissolved in water as a beverage or as ordinary hard gelatin capsules on postprandial hyperglycemia (>140 mg/dL; >7.8 mmol/L) in T2DM patients elicited by a nutritionally-balanced meal providing 50 g of complex carbohydrates.

METHODS

Fasting T2DM patients (n = 19) randomly ingested a standardized meal in five experimental sessions, one alone (Control) and the other after prior intake of 3 or 6 g of crude cinnamon in the form of hard gelatin capsules or powder dissolved in water. Blood glucose was measured at fasting and at 0.25, 0.5, 0.75, 1, 1.5 and 2 hours postprandially. After each breakfast, its palatability scores for visual appeal, smell and pleasantness of taste were assessed, as well as the taste intensity sweetness, saltiness, bitterness, sourness and creaminess.

RESULTS

The intake of raw cinnamon dissolved in water, independently of the dose, decreased the meal-induced large glucose spike (peak-rise of +87 mg/dL and Δ1-hour glycemia of +79 mg/dL) and the hyperglycemic blood glucose peak. When cinnamon was taken as capsules, these anti-hyperglycemic effects were lost or significantly diminished. Raw cinnamon intake did not change time-to-peak or the 2-h post-meal glycaemia, but flattened the glycemic curve (lower iAUC) without changing the shape that is typical of T2DM patients.

CONCLUSIONS

This cinnamon's antihyperglycemic action confirms its acarbose-like property to inhibit the activities of the carbohydrate-digesting enzymes α-amylases/α-glucosidases, which is in accordance with its exceptionally high content of raw insoluble fiber. The efficacy of using raw cinnamon as a diabetes treatment strategy seems to require its intake at a specific time before/concomitantly the main hyperglycemic daily meals. Trial registration: Registro Brasileiro de Ensaios Clínicos (ReBEC), number RBR-98tx28b.

Capsicum annuum L. and its bioactive constituents: A critical review of a traditional culinary spice in terms of its modern pharmacological potentials with toxicological issues

Capsicum annuum L., commonly known as chili pepper, is used as an important spice globally and as a crude drug in many traditional medicine systems. The fruits of C. annuum have been used as a tonic, antiseptic, and stimulating agent, to treat dyspepsia, appetites, and flatulence, and to improve digestion and circulation. The article aims to critically review the phytochemical and pharmacological properties of C. annuum and its major compounds. Capsaicin, dihydrocapsaicin, and some carotenoids are reported as the major active compounds with several pharmacological potentials especially as anticancer and cardioprotectant. The anticancer effect of capsaicinoids is mainly mediated through mechanisms involving the interaction of Ca²⁺ -dependent activation of the MAPK pathway, suppression of NOX-dependent reactive oxygen species generation, and p53-mediated activation of mitochondrial apoptosis in cancer cells. Similarly, the cardioprotective effects of capsaicinoids are mediated through their interaction with cellular transient receptor potential vanilloid 1 channel, and restoration of calcitonin gene-related peptide via Ca²⁺ -dependent release of neuropeptides and suppression of bradykinin. In conclusion, this comprehensive review presents detailed information about the traditional uses, phytochemistry, and pharmacology of major bioactive principles of C. annuum with special emphasis on anticancer, cardioprotective effects, and plausible toxic adversities along with food safety.

The effect of red pepper/capsaicin on blood pressure and heart rate: A systematic review and meta-analysis of clinical trials

Several studies have assessed the effect of red pepper on blood pressure (BP) and heart rate (HR) and reported controversial results. The aim of this study was to perform a systematic review and meta-analysis of clinical trials that evaluated the effect of red pepper/capsaicin consumption on BP and HR. Medline, Scopus, Cochrane Library, and Google Scholar were systematically searched, from database inception to August 2020, to ascertain clinical trials that evaluated the effects of red pepper or capsaicin on systolic blood pressure (SBP), diastolic blood pressure (DBP), or HR. Pooled effect size was calculated using a random-effects method. We performed subgroup analyses to discern probable sources of between-study heterogeneity. Meta-analysis showed no significant effect of red pepper/capsaicin on SBP (0.43 mmHg, 95% CI: -1.15 to 2.01), DBP (-0.45 mmHg, 95% CI: -2.14 to 1.24), and HR (-0.60 bpm, 95% CI: -1.97 to 0.78). Although between-study heterogeneity was high for SBP and DBP, we could not discern the potential sources of heterogeneity. In conclusion, red pepper/capsaicin had no effect on BP and HR. The findings should be interpreted with caution because between-study heterogeneity was high. Further well-designed and high-quality studies are required to investigate the efficacy and safety of red pepper/capsaicin supplement on BP and HR.

Association of Spicy Chilli Food Consumption With Cardiovascular and All-Cause Mortality: A Meta-Analysis of Prospective Cohort Studies

This systematic review and meta-analysis examined the association between spicy food (chilli pepper, chilli sauce, or chilli oil) consumption with cardiovascular and all-cause mortality. Medline and EMBASE were searched from their inception until February 2020 to identify relevant prospective cohort studies. Hazard ratios (HRs)/relative risk (RRs) were pooled via random-effect meta-analysis. Of the 4387 citations identified, 4 studies (from the United States, China, Italy, and Iran) were included in the meta-analysis. The included studies involved a total of 564 748 adults (aged ≥18 years; 51.2% female) followed over a median duration of 9.7 years. The pooled data suggested that compared with people who did not regularly consume spicy food (none/<1 d/wk), regular consumers of spicy food experienced a 12% (HR/RR_pooled 0.88, 95% CI, 0.86-0.90; I ² = 0%) lower risk of all-cause mortality. Moreover, spicy food consumption was associated with significant reduction in the risk of death from cardiac diseases (HR/RR_pooled 0.82, 0.73-0.91; I ² = 0%), but not from cerebrovascular disorders (HR/RR_pooled 0.79, 0.53-1.17; I ² = 72.2%). In conclusion, available epidemiological studies suggest that the consumption of spicy chilli food is associated with reduced risk of all-cause as well as heart disease-related mortality. Further studies in different populations are needed to confirm this association.

Synthesis and characterization of a polyurethane carrier used for a prolonged transmembrane transfer of a chili pepper extract

Purpose

Red chili peppers have been highly valued in gastronomy and traditional medicine since ancient times; it seems that it is not just an ingredient for food but also a good remedy for various medical conditions such as increased blood pressure and high levels of serum triglycerides and cholesterol, myocardial infarction, arthritis, and migraines. The objective of this study is the characterization of a new carrier used for encapsulated extract.

Methods

Chili pepper extract was obtained and was physically entrapped inside polyurethane microparticles in order to diminish the irritative potential of this extract. The particles were evaluated by Zetasizer measurements, small-angle neutron scattering and thermal analysis, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy; the encapsulation efficacy and the drug release profile were assessed by UV-Vis spectroscopy. Bioevaluations on mice skin were performed to predict the irritative potential of the samples.

Results

Two different types of samples were compared: hollow polyurethane microparticles vs polyurethane particles containing the natural extract. The sizes of the particles were very similar, but the sample containing the extract presents three particle populations (the polydispersity index increases from 0.3 to 0.6 from one sample to another). The zeta-potential measurements and SEM images indicate a medium tendency to form clusters, while the UV-Vis study revealed an almost 70% encapsulation efficacy.

Conclusion

The results suggest that encapsulation of a chili pepper extract inside polyurethane microparticles leads to a non-irritative product with a prolonged release: ~30% of encapsulated extract is released within the first 8 days and a maximum 45% is reached in 2 weeks.

Roles of Spicy Foods and Their Bioactive Compounds in Management of Hypercholesterolemia

Hypercholesterolemia, as one of the major risk factors in development of cardiovascular diseases, is of mounting prevalence worldwide in recent years. Many nutraceuticals and phytochemical supplements serve as a promising complementary therapy in the management of hypercholesterolemia. Among them, spicy foods have attracted special attention. Plasma lipid-lowering activity of garlic, ginger, and turmeric have been well-studied in both humans and animals. Consumption of either 3 g/day of ginger or 2 g/day of curcumin for over 4 weeks effectively reduced blood cholesterol in hypercholesterolemia subjects. However, effects of chili and black peppers on blood cholesterol are studied little clinically. The present review is to summarize the findings of recent studies on the efficacy and mechanism of spicy foods and their primary bioactive components in management of hypercholesterolemia from preclinical studies to clinical trials.

Association between Dietary Inflammatory Index and Metabolic Syndrome in the General Korean Population

Inflammation is thought to be partly responsible for metabolic syndrome (MetS). Recently, dietary inflammatory index (DII) was developed to calculate the overall inflammatory potential of a diet. The objective of this study was to investigate the association between DII and MetS, as well as MetS components, using nationally representative survey data. The study sample consisted of 9291 Korean adults (aged 19⁻65 years, 3682 men and 5609 women) who participated in the sixth (2013⁻2015) Korea National Health and Nutrition Examination Survey. DII values were calculated using 24-h dietary recall data. Multivariable-adjusted logistic regression analysis was performed to identify the association between DII and MetS by sex. In the multivariate logistic regression model, the top DII quartile (Q4), was positively associated with MetS prevalence in men (Q4 vs. Q1, OR = 1.40; 95% CI = 1.06⁻1.85; p for linear trend = 0.008) and in postmenopausal women (Q4 vs. Q1, OR = 1.67; 95% CI = 1.15⁻2.44; p for linear trend = 0.008). The top DII quartile was also positively associated with the prevalence of hyperglycemia in men and the prevalence of central obesity in postmenopausal women. Further studies using prospective cohorts are needed to identify the causal relationship between DII and MetS.

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.