Extract of grains of paradise and its active principle 6-paradol trigger thermogenesis of brown adipose tissue in rats

Essential oil components of turmeric inhibit hepatic lipidification and liver fibrosis in a diet-induced NASH model rats

In this study, the fraction extracted from turmeric powder with 50% ethanol and fractionated with n-hexane were administered to diet-induced NASH model rats. NASH model was prepared with SD rats by feeding an originally designed choline-deficient, high-fat, high-fructose (HFF-CD) diet for 10 weeks. To the HFF-CD diet, hexane fraction and 50% ethanol fraction after hexane fractionation were added at 100 mg/kg body weight. 10 weeks later, blood samples and liver were collected for the following parameters: lipid weights, serum ALT, AST, TG, liver TG, TBARS levels, lipid metabolism-related gene expression and histopathological examination of the liver. As the results, the hexane fraction and 50% ethanol fraction showed a decrease in lipid weight, a decrease in hepatic TG, and activation of PPAR-α in the lipid metabolism-related gene test. These results suggest that the hexane fraction of turmeric has an inhibitory effect on fat accumulation in the liver by promoting lipid metabolism in NASH model rats.

Aframomum melegueta Seed Extract with Standardized Content of 6-Paradol Reduces Visceral Fat and Enhances Energy Expenditure in Overweight Adults - A Randomized Double-Blind, Placebo-Controlled Clinical Study

PURPOSE

Aframomum melegueta (grains of paradise) seeds have been demonstrated to possess thermogenic potential. However, it is necessary to validate the functional attributes of A. melegueta seed extract in human subjects.

METHODS

In a double-blind, placebo-controlled clinical trial design, we have examined the thermogenic effects of a standardized A. melegueta seed extract (AfperFit). A total of 70 overweight male and female subjects (BMI ≥25.0 to ≤30.0 kg/m²) aged 20-50 years were enrolled and administered with either 250 mg of AfperFit or placebo in capsule form twice daily for 12 weeks. The primary efficacy endpoints included energy expenditure (indirect calorimetry), body composition (dual-energy X-ray absorptiometry (DEXA)) and fat distribution (computed tomography (CT scan)), analyzed at baseline and after 12 weeks of treatment. The effect of intervention on the quality of life was examined using SF-12 questionnaire.

RESULTS

Consumption of AfperFit significantly increased the energy expenditure (p<0.01), visceral fat area (p<0.001) and visceral to subcutaneous fat ratio (p<0.01) compared to placebo group. Consequently, there was significant body weight loss and reduction in BMI of subjects in AfperFit group compared to placebo (p<0.01). The safety evaluation showed that biochemical and hematological parameters were in the normal range. Supplementation of AfperFit was well tolerated during the study and no adverse effects were observed.

CONCLUSION

Overall, this study validates the health benefits of A. melegueta seed extract as fat burner and recommends its use as a functional ingredient to improve the quality of life and general health.

Pungent and volatile constituents of dried Australian ginger

Ginger is well known for its pungent flavour and health-benefitting properties, both of which are imparted by various gingerol derivatives and other volatile constituents. Although there has been a considerable amount of research into the chemical constituents found in fresh ginger, there is little information available on the quality of Australian-grown dried ginger, particularly that intended for processing purposes. Here, we investigate differences in the chemical composition of three samples of processing-grade ginger, ranging from very poor to good quality. Gingerols and 6-shogaol were quantified using high performance liquid chromatograph (HPLC), while gas chromatography coupled with mass spectrometry (GC-MS) was used to identify and semi-quantify the volatile constituents and other gingerol derivatives. Significant differences were found between the samples in their content of gingerols and [6]-shogaol, as well as in their total phenolic content and antioxidant capacity. A total of 100 volatile compounds were identified in the dried ginger samples, including 54 terpenoid derivatives and 35 gingerol derivatives. Several compounds are reported from ginger for the first time, including limonene glycol and neryl laurate. In addition, we provide the second report of the presence of shyobunol, geranyl-p-cymene and geranyl-α-terpinene in ginger.

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Pungent and volatile compounds studied in ginger of varying quality.

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Several volatile compounds reported from ginger for the first time.

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Samples varied significantly in gingerol, [6]-shogaol and volatile content.

Prolonged Treatment with Grains of Paradise (Aframomum melegueta) Extract Recruits Adaptive Thermogenesis and Reduces Body Fat in Humans with Low Brown Fat Activity

Increasing adaptive thermogenesis through the activation of brown adipose tissue (BAT) is a promising practical strategy for preventing obesity and related disorders. Ingestion of a single dose of 40 mg of an extract of Grains of Paradise (GP), a ginger family species, reportedly triggers BAT thermogenesis in individuals with high but not in those with low BAT activity. We hypothesized that prolonged treatment with GP might revive BAT in individuals who have lost active BAT. In the present study, we recruited 9 healthy young male volunteers with reduced BAT that was assessed by fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) following 2-h cold exposure at 19ºC. The subjects ingested GP extract (40 mg/d) or placebo every day for 5 wk. Before and after the treatment with either GP or placebo, their body composition and BAT-dependent cold-induced thermogenesis (CIT)-a non-invasive index of BAT-were measured in a single-blinded, randomized, placebo-controlled cross-over design. Their whole-body resting energy expenditure at a thermoneutral condition remained unchanged following GP treatment. However, CIT after treatment was significantly higher in GP-treated individuals than in placebo-treated individuals. Body weight and fat-free mass did not change significantly following GP or placebo treatment. Notably, body fat percentage slightly but significantly decreased after GP treatment but not after placebo treatment. These results suggest that repeated ingestion of GP elevates adaptive thermogenesis through the re-activation of BAT, thereby reducing body fat in individuals with low BAT activity.

6-Paradol Acts as a Potential Anti-obesity Vanilloid from Grains of Paradise

SCOPE

Grains of Paradise (GOP), the seeds of Aframomum melegueta, has anti-obesity effects. However, the mechanisms underlying the effects remain unclear.

METHODS AND RESULTS

This study sets up to study the anti-obesity impact and homeostatic effects of 6-paradol, a major vanilloid found in GOP, and investigates the physiological outputs and the lipometabolism-related gene in fat and liver in high-fat-induced obese mice with a comparison with structurally similar vanilloids (6-gingerol and 6-shogaol). The vanilloids are synthesized in adequate quantities for performing animal experiments and orally administered to 6-week-old male mice over 2 weeks. This study found that 6-paradol decreased body weight gain and visceral and subcutaneous fats in 2 weeks, whereas 6-gingerol and 6-shogaol have no effect. Additionally, 6-paradol suppresses the hepatic cholesterol and triglyceride and significantly decreases the gene expression related to fatty acid synthesis, lipid transportation, and adipocyte differentiation in both liver and adipose tissue. Moreover, phosphorylation of AMP-activated protein kinase (AMPK) that greatly contributes to lipometabolism is promoted by 6-gingerol but not 6-paradol.

CONCLUSION

These results suggest that 6-paradol regulates several obesity-related genes in an AMPK-independent manner. Therefore, it could be the principal active vanilloid in GOP giving it anti-obesity properties with a different mechanism.

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.

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.

Translational Aspects of Brown Fat Activation by Food-Derived Stimulants

Since the rediscovery of brown adipose tissue (BAT) in humans, its energy-dissipating ability has been well-recognized. The negative correlations of BAT activity with adiposity and insulin sensitivity provided an obvious rationale for discerning reliable and practical strategies for stimulating BAT. Though cold exposure or use of pharmacological adrenomimetics can activate BAT, they may have adverse effects. Therefore, determining alternative stimulants of BAT with lower risks such as commonly used food ingredients is highly desirable. Recent observations revealed that chemical activation of temperature-sensitive transient receptor potential (TRP) channels by food ingredients can recruit BAT in humans. Furthermore, animal studies have identified several food-derived stimulants of BAT acting through multiple mechanisms distinct from a TRP-mediated process. Dietary compounds acting as an activator of Sirtuin 1, a critical regulator of mitochondrial biogenesis and brown adipocyte differentiation, are one such class of promising food-derived BAT activators in humans. While the individual effects of various dietary factors are increasingly established in a laboratory setting, the potential synergistic effects of multiple stimulants on BAT remain to be tested in a clinical environment. These investigations may support the development of efficient, flexible dietary regimens capable of boosting BAT thermogenesis.

Dietary Factors Promoting Brown and Beige Fat Development and Thermogenesis

Brown adipose tissue (BAT) is a specialized fat tissue that has a high capacity to dissociate cellular respiration from ATP utilization, resulting in the release of stored energy as heat. Adult humans possess a substantial amount of BAT in the form of constitutively active brown fat or inducible beige fat. BAT activity in humans is inversely correlated with adiposity, blood glucose concentrations, and insulin sensitivity; this suggests that strategies aimed at BAT-mediated bioenergetics are an attractive therapeutic target in combating the continuing epidemic of obesity and diabetes. Despite advances in knowledge regarding the developmental lineage and transcriptional regulators of brown and beige adipocytes, our current understanding of environmental modifiers of BAT thermogenesis, such as diet, is limited. In this review, we consolidated the latest research on dietary molecules that may serve to promote BAT thermogenesis. Here, we summarized the thermogenic function of selected phytochemicals (e.g., capsaicin, resveratrol, curcumin, green tea, and berberine), dietary fatty acids (e.g., fish oil and conjugated linoleic acids), and all-trans retinoic acid, a vitamin A metabolite. We also delineated the proposed mechanisms whereby these dietary molecules promote BAT activity and/or browning of white adipose tissue. Characterizing thermogenic dietary factors may offer novel insight into revising nutritional intervention strategies aimed at obesity and diabetes prevention and management.

Pharmacokinetics of Paradol Analogues Orally Administered to Rats

The kinetics parameters of paradols with different acyl chain lengths have been evaluated to determine their antiobesity site of action. Rats were orally administered olive oil containing 0-, 6-, 8-, or 12-paradol, and blood samples were collected at different time points. The concentrations of the paradols in the plasma were analyzed both with and without β-glucuronidase treatment. The area under the plasma concentration-time curve from 0 to 24 h (AUC(0-24h)) of the parent compounds decreased with increasing acyl chain length. Whereas 12-paradol showed the largest AUC(0-24h) with the longest time to reach its maximum plasma concentration of all of the compounds tested, the AUC(0-24h) values of the metabolites decreased with increasing acyl chain length. These results indicate that increasing acyl chain length leads to a decrease in the absorption of paradols via the intestinal tract, the wall of which was estimated to be their antiobesity site of action.

Medicinal plants used as excipients in the history in Ghanaian herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

The present study was carried out to investigate the traditional use, pharmacology and active compounds of four plants commonly used as excipients in herbal medicine in Ghana.

MATERIALS AND METHODS

A comprehensive literature search was conducted to gain knowledge about the traditional use, pharmacology and active compounds of the four plant excipients. The broth dilution antibacterial assay and the DPPH radical scavenging antioxidant assay were used to evaluate the antibacterial and antioxidant activity of the plants, respectively. Ethanol, warm water and cold water extracts were prepared from the dried seeds/fruits of Aframomum melegueta, Piper guineense, Xylopia aethiopica and Monodora myristica, and tested in the assays.

RESULTS

A. melegueta and P. guineense seemed to act as pharmacoenhancers, since they have been shown to inhibit specific CYP-enzymes. A. melegueta could act as an antioxidant to preserve herbal preparations. None of the plant excipients had antibacterial activity against the bacteria tested in this study. Compounds with an aromatic or pungent smell had been identified in all the plant excipients. An explanation for the use of the plants as excipients could rely on their taste properties.

CONCLUSION

The present study suggests that there may be more than one simple explanation for the use of these four plants as excipients. Plausible explanations have been proven to be: (1) a way to increase the effect of the medicine, (2) a way to make the medicine more palatable or (3) a way to preserve the activity of the medicinal preparation over time.

Relationship between the acyl chain length of paradol analogues and their antiobesity activity following oral ingestion

6-Paradol is known to activate thermogenesis in brown adipose tissue (BAT), and paradol analogues with different acyl chain lengths possess different pungency thresholds. In this study, the influence of the acyl chain length on the antiobesity activity of the paradol analogues was investigated. The antiobesity activity of 6-paradol in mice fed a high-fat diet for 8 weeks was greater than that of dihydrocapsiate. A comparison of the antiobesity activities of zingerone and 6-paradol showed that the length of the acyl chain in the paradol analogue was important for strong activity. Furthermore, the antiobesity activities of 6-, 8-, and 12-paradol appeared to decrease in an acyl chain length-dependent manner. The mechanism of the antiobesity activity of 6-paradol was enhanced by increasing levels of energy metabolism in the BAT, as well as an increase in the expression of uncoupling proteins 1 via the activation of sympathetic nerve activity.

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

PURPOSE OF REVIEW

Capsaicin and its nonpungent analog (capsinoids) are known to be food ingredients that increase energy expenditure and decrease body fat. This article reviews the role of brown adipose tissue (BAT) for the thermogenic effect of these compounds in humans and proposes the possibility of some other antiobesity food ingredients.

RECENT FINDINGS

A single oral ingestion of capsinoids increases energy expenditure in human individuals with metabolically active BAT, but not those without it, indicating that capsinoids activate BAT and thereby increase energy expenditure. This finding gave a rational explanation for discrepant results of the effects of capsinoids in the previous studies. Human BAT may be largely composed of inducible 'beige' adipocytes more than typical brown adipocytes because its gene expression patterns are similar to beige cells isolated from murine white fat depots. In fact, preadipocytes isolated from supraclavicular fat deposits - where BAT is often detected - are capable of differentiating into brown-like adipocytes in vitro, providing evidence of inducible brown adipogenesis in adult humans.

SUMMARY

As human BAT may be inducible, a prolonged ingestion of capsinoids would recruit active BAT and thereby increase energy expenditure and decrease body fat. In addition to capsinoids, there are numerous food ingredients that are expected to activate BAT and so be useful for the prevention of obesity in daily life.

Grains of paradise (Aframomum melegueta) extract activates brown adipose tissue and increases whole-body energy expenditure in men

Brown adipose tissue (BAT) is responsible for cold- and diet-induced thermogenesis, and thereby contributes to the control of whole-body energy expenditure (EE) and body fat content. BAT activity can be assessed by fluoro-2-deoxyglucose (FDG)-positron emission tomography (PET) in human subjects. Grains of paradise (GP, Aframomum melegueta), a species of the ginger family, contain pungent, aromatic ketones such as 6-paradol, 6-gingerol and 6-shogaol. An alcohol extract of GP seeds and 6-paradol are known to activate BAT thermogenesis in small rodents. The present study aimed to examine the effects of the GP extract on whole-body EE and to analyse its relation to BAT activity in men. A total of nineteen healthy male volunteers aged 20–32 years underwent FDG-PET after 2 h of exposure to cold at 19°C with light clothing. A total of twelve subjects showed marked FDG uptake into the adipose tissue of the supraclavicular and paraspinal regions (BAT positive). The remaining seven showed no detectable uptake (BAT negative). Within 4 weeks after the FDG-PET examination, whole-body EE was measured at 27°C before and after oral ingestion of GP extract (40 mg) in a single-blind, randomised, placebo-controlled, crossover design. The resting EE of the BAT-positive group did not differ from that of the BAT-negative group. After GP extract ingestion, the EE of the BAT-positive group increased within 2 h to a significantly greater (P< 0·01) level than that of the BAT-negative group. Placebo ingestion produced no significant change in EE. These results suggest that oral ingestion of GP extract increases whole-body EE through the activation of BAT in human subjects.