Phytochemicals in the Control of Human Appetite and Body Weight

Appetite Suppressing Activity of Rumex Usambarensis Leaf and Stem Aqueous Extract in Wistar Albino Female Rats: an in vivo Experimental Study

Background

The burden of obesity and overweight associated morbidity and mortality is increasing in epidemic proportions worldwide. Suppression of appetite is one of the mechanisms that has been shown to reduce weight. Most of the drugs on the market currently for appetite suppression are not readily available or affordable in resource-limited settings. Additionally, previous studies have shown that most of these drugs are associated with significant adverse effects, which demonstrates a need for alternative or complementary options of drugs for appetite suppression. In Uganda, herdsmen commonly chew the raw stems and leaves of Rumex usambarensis, a wild shrub, and this is believed to reduce hunger. This study aimed at determining the effect of Rumex usambarensis aqueous extract on food intake as a measure of appetite in Wistar albino rats.

Methods

This study was carried out in two phases: the fattening phase and the treatment phase. Female albino Wistar rats were fed a high-fat diet for 49 days. The fattened animals were then randomly separated into 4 groups, which received 1 mL of distilled water (negative control), 500 mg/kg body weight of aqueous extract of Rumex usambarensis, 1000 mg/kg body weight of the extract and 20 mg/kg body weight topiramate (positive control), respectively. Food intake was measured every day, and weights were taken every two days for every group.

Results

Rumex usambarensis extract significantly reduced body weight of fattened rats compared to the control group at both doses: for the 500mg/kg dose (Mean difference, MD = 17.2, p < 0.001) and for 1000mg/kg dose (MD = 25.9, p < 0.001). Additionally, both doses of the aqueous extract showed a significant reduction in food intake: for the 500mg/kg dose (MD = 16.1, p < 0.001) and for the 1000mg/kg dose (MD = 37.3, p < 0.001). There was a strong correlation between food intake and weight for both doses for the 500mg/kg dose (r = 0.744, p = 0.009), and the strongest association observed with 1000mg/kg dose (r = 0.906, p < 0.001).

Conclusion

The aqueous extract of the leaves and stems of Rumex usambarensis has appetite suppressing and weight reduction effects in fattened female Wistar albino rats and could be an efficacious alternative medicine for management of overweight, obesity and other related disorders.

Overview of Natural Supplements for the Management of Diabetes and Obesity

Bioactive compounds found in various natural sources, such as fruits, vegetables, and herbs, have been studied for their potential benefits in managing obesity and diabetes. These compounds include polyphenols, flavonoids, other antioxidants, fiber, and certain fatty acids. Studies have found that these compounds may improve insulin sensitivity, regulate blood sugar levels, and promote weight loss. However, the effects of these compounds can vary depending on the type and amount consumed, as well as individual factors, such as genetics and lifestyle. Nutraceutical substances have multifaceted therapeutic advantages, and they have been reported to have disease-prevention and health-promoting properties. Several clinically used nutraceuticals have been shown to target the pathogenesis of diabetes mellitus, obesity, and metabolic syndrome and their complications and modulate various clinical outcomes favorably. This review aims to highlight and comment on some of the most prominent natural components used as antidiabetics and in managing obesity.

Association of dietary phytochemical index with cardiometabolic risk factors

Objective(s): Cardio-metabolic risk factors are becoming a global health concern. To address this problem, one of the proposed ways is to focus on phytochemical-rich foods consumption. Therefore, we aimed to summarize the results of observational studies (cohorts, case-control, and cross-sectional) that investigated the association between dietary phytochemical index (PI) as a new index for evaluating phytochemical-rich food intake and various risk factors of cardio-metabolic disorders. Methods: We conducted a comprehensive systematic review through PubMed, Scopus, and Web of Science databases. The literature search was performed up to August 2021 with no publication year restriction on observational studies investigating the association between PI and cardiometabolic risk factors on adults and children. A random-effect meta-analysis was used. Results: Overall, 16 articles (cross-sectional, case-control, cohort) were eligible for this systematic review and 8 studies with 99771 participants were included in the meta-analysis. Random effect meta-analysis showed that adherence to higher dietary PI decrease the odds of abdominal obesity (OR: 0.73, 95% CI: 0.58, 0.88, I2: 84.90), generalized obesity (OR: 0.84, 95% CI: 0.69, 0.98, I2: 68.10), hypertriglyceridemia (OR: 0.81, 95% CI: 0.73, 0.89, I2: 0.00), hypertension (OR: 0.86, 95% CI: 0.73, 0.99, I2: 7.02), and MetS (OR: 0.79, 95% CI: 0.69, 0.88, I2: 84.90). However, results considering the associations between dietary PI with glycemic indices, and low high-density lipoprotein cholesterol (HDL-C) were not significant (p<0.05). Conclusion: Evidence showed adverse associations between dietary PI and some cardio-metabolic risk factors such as obesity, hypertriglyceridemia, hypertension and metabolic syndrome.

Natural products as novel anti-obesity agents: insights into mechanisms of action and potential for therapeutic management

Obesity affects more than 10% of the adult population globally. Despite the introduction of diverse medications aimed at combating fat accumulation and obesity, a significant number of these pharmaceutical interventions are linked to substantial occurrences of severe adverse events, occasionally leading to their withdrawal from the market. Natural products serve as attractive sources for anti-obesity agents as many of them can alter the host metabolic processes and maintain glucose homeostasis via metabolic and thermogenic stimulation, appetite regulation, pancreatic lipase and amylase inhibition, insulin sensitivity enhancing, adipogenesis inhibition and adipocyte apoptosis induction. In this review, we shed light on the biological processes that control energy balance and thermogenesis as well as metabolic pathways in white adipose tissue browning, we also highlight the anti-obesity potential of natural products with their mechanism of action. Based on previous findings, the crucial proteins and molecular pathways involved in adipose tissue browning and lipolysis induction are uncoupling protein-1, PR domain containing 16, and peroxisome proliferator-activated receptor-γ in addition to Sirtuin-1 and AMP-activated protein kinase pathway. Given that some phytochemicals can also lower proinflammatory substances like TNF-α, IL-6, and IL-1 secreted from adipose tissue and change the production of adipokines like leptin and adiponectin, which are important regulators of body weight, natural products represent a treasure trove for anti-obesity agents. In conclusion, conducting comprehensive research on natural products holds the potential to accelerate the development of an improved obesity management strategy characterized by heightened efficacy and reduced incidence of side effects.

The controversial effect of smoking and nicotine in SARS-CoV-2 infection

The effects of nicotine and cigarette smoke in many diseases, notably COVID-19 infection, are being debated more frequently. The current basic data for COVID-19 is increasing and indicating the higher risk of COVID-19 infections in smokers due to the overexpression of corresponding host receptors to viral entry. However, current multi-national epidemiological reports indicate a lower incidence of COVID-19 disease in smokers. Current data indicates that smokers are more susceptible to some diseases and more protective of some other. Interestingly, nicotine is also reported to play a dual role, being both inflammatory and anti-inflammatory. In the present study, we tried to investigate the effect of pure nicotine on various cells involved in COVID-19 infection. We followed an organ-based systematic approach to decipher the effect of nicotine in damaged organs corresponding to COVID-19 pathogenesis (12 related diseases). Considering that the effects of nicotine and cigarette smoke are different from each other, it is necessary to be careful in generalizing the effects of nicotine and cigarette to each other in the conducted researches. The generalization and the undifferentiation of nicotine from smoke is a significant bias. Moreover, different doses of nicotine stimulate different effects (dose-dependent response). In addition to further assessing the role of nicotine in COVID-19 infection and any other cases, a clever assessment of underlying diseases should also be considered to achieve a guideline for health providers and a personalized approach to treatment.

Luteolin protects against adipogenic and lipogenic potency induced by human relevant mixtures of persistent organic pollutants (POPs) in the 3T3-L1 model

Human exposure to persistent organic pollutants (POPs) may contribute to obesogenic effects. We have previously shown that POP mixtures modelled on blood levels relevant to the Scandinavian population induces adipogenic effects in the mouse 3T3-L1 cell line. Luteolin is a flavone that has shown anti-lipogenic and anti-adipogenic effects on adipogenesis in in vitro models. In this study, luteolin has been applied to inhibit adipocyte formation and intracellular lipid content increase induced by a human relevant mixture of POPs. 3T3-L1 cells were exposed to a POP mixture consisting of 29 chemicals, including amongst others polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), perfluoroalkylated acids (PFAAs), and polybrominated diphenyl ethers (PBDEs). Rosiglitazone was applied as a positive lipogenic control. Luteolin was tested between 0.5 and 10 μM. High content analysis was used to assess changes in adipocyte formation and intracellular lipid content in the 3T3-L1 cell line. Luteolin significantly reduced POP-induced adipocyte formation at 2, 5 and 10 μM, and lipid accumulation at 10 μM. Interestingly, luteolin did not affect rosiglitazone induced adipo- and lipogenic effects, suggesting differences in mechanisms of action. In conclusion, this in vitro study shows that dietary polyphenols such as luteolin may protect against POP induced adipo- and lipogenic effects.

Prevalence and Correlates of Anemia among Adolescents Living in Hodeida, Yemen

This study assesses the prevalence and correlates of anemia among adolescents living in the war-affected region of Hodeida in Yemen. A secondary objective was to examine the effect of a nutrition education intervention on hemoglobin levels among anemic adolescents. A cross-sectional study was conducted on a random sample of adolescents aged 15–19 years in Hodeida (n = 400). A questionnaire was administered to inquire about demographic, socioeconomic, lifestyle and clinical characteristics. Capillary blood was obtained, anthropometric characteristics were measured and stool samples were collected. As for the secondary objective, anemic adolescents were randomly assigned to an intervention group (nutrition education and iron supplementation) and a control group (iron supplements only). The prevalence of anemia was 37.8%. Female gender, khat chewing, excessive menstruation, and experiencing headaches, fatigue, or dizziness were independent predictors of anemia. In contrast, adolescents who attended private schools, and reported snack consumption or handwashing had a significantly lower risk of anemia. A sample of 116 adolescents participated in the intervention (3 months). Hemoglobin levels were significantly higher in the intervention group compared to the control. Our findings contribute to the identification of high-risk groups that should be targeted by context-specific interventions. The implemented multicomponent intervention may serve as a prototype for larger-scale preventive programs.

Russelioside B: a Pregnane Glycoside with Pharmacological Potential

Pregnanes and pregnane glycosides or their esters are well-studied secondary metabolites, many of them exhibit immunomodulator, anticancer, antidiabetic, antarthritic, antiulcer, anti-nociceptive, hypolipidemic, anti-inflammatory, and antibacterial properties. Pregnane glycosides are widely distributed in the families Apocyanaceae and Asclepiadaceae. Plant members of the genus Caralluma R.Br., Apocynaceae, are among the most studied species because of uses in traditional medicine or as food. They are a rich source of pregnane glycosides, as russelioside B. However, the bioactivity profile of this pregnane glycoside has not been reviewed until now. The present review aims to summarize the most important pharmacological and therapeutic applications of russelioside B with specific emphasis on the mechanism of actions associated with its administration in preclinical models. Russelioside B has many pharmacological effects including antidiabetic, anti-obesity, anti-nociceptive, antiulcer, anti-inflammatory, anti-arthritis effects, and antibiofilm, and wound healing activities. Despite its outstanding pharmacotherapeutic potential, russelioside B has never been tested in clinical trials. This review indicates that russelioside B is a potentially promising bioactive candidate, but further deeper mechanistic studies and clinical trials are needed in the future to elucidate its interaction with receptors of specific genes.

Association between the Phytochemical Index and Overweight/Obesity: A Meta-Analysis

Some studies suggest that a higher phytochemical index (PI) is associated with a lower risk of overweight/obesity. This meta-analysis is performed to summarize published studies on the relationship of PI and the risk of overweight/obesity. We searched on PubMed, Cochrane Library and Web of Science from the inception dates to February 2022. The random-effect model was used based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Begg’s and Egger’s tests. The dose–response relationship was assessed using a restricted cubic spline model. Nine studies were included in the meta-analysis, with a total of 100,753 participants. The meta-analysis showed that the phytochemical index was associated with a decreased risk of overweight/obesity. The pooled OR (95% CI) was 0.81 (0.74–0.90). The findings from dose–response analysis showed a nonlinear association between the phytochemical index and the risk of overweight/obesity. The results of the meta-regression showed that gender and area were significant covariates influencing the heterogeneity between studies. There was no publication bias in the meta-analysis of this study. In conclusion, although this meta-analysis indicates that a high phytochemical index is associated with a reduced risk of overweight/obesity, all the studies included in this meta-analysis were cross-sectional studies with high heterogeneity. As such, more data from randomized controlled trials are required to confirm the efficacy of PI in evaluating the risk of overweight/obesity.

An extract of hops (Humulus lupulus L.) modulates gut peptide hormone secretion and reduces energy intake in healthy-weight men: a randomized, crossover clinical trial

BACKGROUND

Gastrointestinal enteroendocrine cells express chemosensory bitter taste receptors that may play an important role in regulating energy intake (EI) and gut function.

OBJECTIVES

To determine the effect of a bitter hop extract (Humulus lupulus L.) on acute EI, appetite, and hormonal responses.

METHODS

Nineteen healthy-weight men completed a randomized 3-treatment, double-blind, crossover study with a 1-wk washout between treatments. Treatments comprised either placebo or 500 mg of hop extract administered in delayed-release capsules (duodenal) at 11:00 h or quick-release capsules (gastric) at 11:30 h. Ad libitum EI was recorded at the lunch (12:00 h) and afternoon snack (14:00 h), with blood samples taken and subjective ratings of appetite, gastrointestinal (GI) discomfort, vitality, meal palatability, and mood assessed throughout the day.

RESULTS

Total ad libitum EI was reduced following both the gastric (4473 kJ; 95% CI: 3811, 5134; P = 0.006) and duodenal (4439 kJ; 95% CI: 3777, 5102; P = 0.004) hop treatments compared with the placebo (5383 kJ; 95% CI: 4722, 6045). Gastric and duodenal treatments stimulated prelunch ghrelin secretion and postprandial cholecystokinin, glucagon-like peptide 1, and peptide YY responses compared with placebo. In contrast, postprandial insulin, glucose-dependent insulinotropic peptide, and pancreatic polypeptide responses were reduced in gastric and duodenal treatments without affecting glycemia. In addition, gastric and duodenal treatments produced small but significant increases in subjective measures of GI discomfort (e.g., nausea, bloating, abdominal discomfort) with mild to severe adverse GI symptoms reported in the gastric treatment only. However, no significant treatment effects were observed for any subjective measures of appetite or meal palatability.

CONCLUSIONS

Both gastric and duodenal delivery of a hop extract modulates the release of hormones involved in appetite and glycemic regulation, providing a potential "bitter brake" on EI in healthy-weight men.

Relationship between Undernutrition and Periodontal Diseases among a Sample of Yemeni Population: A Cross-Sectional Study

Undernutrition is an inadequate supply of energy and nutrients. Periodontal diseases (PDs) are defined as a broad form of chronic inflammatory disease of the gingiva, bone, and ligaments supporting the teeth. This study aimed to reveal the relationship between undernutrition, using body mass index (BMI) and serum albumin level (Alb), and PDs in a sample of Yemeni population. A cross-sectional study was conducted at dental teaching clinics at the Faculty of Dentistry, Sana’a University. Of 1920 patients who attended clinics, only 229 matched the study criteria. Oral examination was performed to assess the periodontal clinical parameter measurements. BMI and Alb were measured. Participants of both genders were involved, with a slight increase in males (n = 134, 58.5%), and most of the study sample was in the age group of 18–35 years (n = 209, 91.3%). Regarding habits, only 18.2% (n = 43) of patients were smokers and about half of the participants (n = 136, 59.4%) were khat chewers. Most cases had mild undernutrition according to BMI (n = 139, 60.7%) and normal Alb level (n = 213, 93%). Regarding the periodontal diagnosis, most of the participants were diagnosed with gingivitis (n = 186, 81.2%). BMI and albumin level were nonsignificantly associated with PDs. PDs were statistically significant with the participant’s age, gender, level of education, and smoking ( $P>0.05$ ). However, BMI, khat chewing, and albumin level were nonsignificant factors of periodontal diseases among Yemeni participants ( $P>0.05$ ). In both genders, variables such as age of the patients, smoking, khat chewing, and PDs were nonsignificantly associated with BMI. This study showed that the majority of the participants had been diagnosed with gingivitis, but there was not an association between PDs and undernutrition. This paper is presented on research square URL // https://www.researchsquare.com/article/rs-429796/v1 with DOI 10.21203/rs.3.rs-429796/v1.

Khat, a Cultural Chewing Drug: A Toxicokinetic and Toxicodynamic Summary

Khat (Catha edulis) is a recreational, chewed herbal drug that has been used as a psychostimulant for centuries in East Africa and the Arabian Peninsula, namely in Somalia, Ethiopia, and Yemen. However, the growing worldwide availability of khat has produced widespread concern. The plant comprises a large number of active substances, among which cathinone, cathine, and norephedrine are the main constituents, which can be included in the group of sympathomimetics of natural origin. In fact, these compounds are amphetamine analogues, and, as such, they have amphetamine-like nervous system stimulant effects. Chewing the leaves gives people a sensation of well-being and increases energy, alertness, and self-confidence. The chronic use of khat is, however, associated with severe cardiac, neurological, psychological, and gastrointestinal complications. The psychological dependence and withdrawal symptoms of khat are the reasons for its prolonged use. The aim of this paper is to review current knowledge on the khat plant with toxicokinetic and toxicodynamic perspectives. Namely, this review paper addresses in vitro, in vivo, and human studies. The models used, as well as the concentrations and doses with the respective biological effects, are discussed. Additionally, the main drug interactions involved with khat are described.

Interaction between CETP Taq1B polymorphism and HEI, DQI and DPI on metabolic biomarkers in patients with type 2 diabetes

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a multidimensional consequence of environmental and genetic factors. Cholesteryl ester transfer protein (CETP) Taq1B polymorphism has been reported as a main predictor of dyslipidaemia, comprising an important complication in persons with T2DM. However, diet could affect T2DM patients metabolic health.

METHODS

We investigated the combination of gene-diet effects on some metabolic biomarkers. In our cross-sectional study, blood samples of 220 patients were collected. Dietary indices (healthy eating index, dietary quality index and dietary phytochemical index) were obtained from a validated semi-quantitative food frequency questionnaire. CETP Taq1B polymorphism was genotyped by a polymerase chain reaction-restriction fragment polymorphism method. Data were analysed by analysis of covariance.

RESULTS

The interaction between the CETP Taq1B polymorphism and dietary indices on low density lipoprotein/high density lipoprotein was significant (p < 0.001 both crude and adjusted models). In addition, the interaction between polymorphism and dietary quality index on total antioxidant capacity (p = 0.004 crude model, p = 0.005 after adjusting) and pentraxin 3 (p = 0.01 both crude and adjusted models) was significant. Also, the interaction between polymorphism and healthy eating index on waist circumference (p = 0.005 both crude and adjusted models) and dietary phytochemical index on interleukin-18 (p = 0.03 crude model) was significant.

CONCLUSIONS

Our results indicated the effect of CETP Taq1B polymorphism on some inflammatory and anthropometrics markers (total antioxidant capacity, pentraxin 3, interleukin-18, low density lipoprotein/high density lipoprotein and waist circumference) with high and low adherence to dietary incides.

Adipose and non-adipose perspectives of plant derived natural compounds for mitigation of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Phyto-preparations and phyto-compounds, by their natural origin, easy availability, cost-effectiveness, and fruitful traditional uses based on accumulated experiences, have been extensively explored to mitigate the global burden of obesity.

AIM OF THIS REVIEW

The review aimed to analyse and critically summarize the prospect of future anti-obesity drug leads from the extant array of phytochemicals for mitigation of obesity, using adipose related targets (adipocyte formation, lipid metabolism, and thermogenesis) and non-adipose targets (hepatic lipid metabolism, appetite, satiety, and pancreatic lipase activity). Phytochemicals as inhibitors of adipocyte differentiation, modulators of lipid metabolism, and thermogenic activators of adipocytes are specifically discussed with their non-adipose anti-obesogenic targets.

MATERIALS AND METHODS

PubMed, Google Scholar, Scopus, and SciFinder were accessed to collect data on traditional medicinal plants, compounds derived from plants, their reported anti-obesity mechanisms, and therapeutic targets. The taxonomically accepted name of each plant in this review has been vetted from "The Plant List" (www.theplantlist.org) or MPNS (http://mpns.kew.org).

RESULTS

Available knowledge of a large number of phytochemicals, across a range of adipose and non-adipose targets, has been critically analysed and delineated by graphical and tabular depictions, towards mitigation of obesity. Neuro-endocrinal modulation in non-adipose targets brought into sharp dual focus, both non-adipose and adipose targets as the future of anti-obesity research. Numerous phytochemicals (Berberine, Xanthohumol, Ursolic acid, Guggulsterone, Tannic acid, etc.) have been found to be effectively reducing weight through lowered adipocyte formation, increased lipolysis, decreased lipogenesis, and enhanced thermogenesis. They have been affirmed as potential anti-obesity drugs of future because of their effectiveness yet having no threat to adipose or systemic insulin sensitivity.

CONCLUSION

Due to high molecular diversity and a greater ratio of benefit to risk, plant derived compounds hold high therapeutic potential to tackle obesity and associated risks. This review has been able to generate fresh perspectives on the anti-diabetic/anti-hyperglycemic/anti-obesity effect of phytochemicals. It has also brought into the focus that many phytochemicals demonstrating in vitro anti-obesogenic effects are yet to undergo in vivo investigation which could lead to potential phyto-molecules for dedicated anti-obesity action.

Toxicopathological, proinflammatory and stress response evaluation of Terminalia catappa extract in male Wistar rats

The present study was carried out to assess the oral safety, proinflammatory and stress response effect of Terminalia catappa aqueous leaf extract (TCA) in male Wistar rats. The acute and sub-acute oral toxicity of TCA was assessed using guidelines 423 and 407 of the Organisation for Economic Co-operation and Development (OECD), respectively. Signs of clinical toxicity, morbidity and mortality were observed. The biochemical, haematological, proinflammatory, stress response and histopathological indices were assessed. In the acute toxicity study, no sign of clinical toxicity, morbidity, and mortality was observed for TCA treatment, up to 5000 mg/kg bwt. However, in the sub-acute toxicity study, repeated daily TCA treatment significantly (p<0.05) altered the body weight gain, plasma alkaline phosphatase activity and albumin concentration. There were no obvious morphological and macroscopic alterations in the organs investigated. TCA appear not to elicit any proinflammatory, stress, systemic and organ toxic effect when utilised at the reported dose and time frame.

The relation between dietary phytochemical index and metabolic syndrome and its components in a large sample of Iranian adults: a population-based study

Background

Despite the protective effects of foods being rich in phytochemicals against chronic diseases, this issue is still poorly understood. The aim of this study was to investigate the association between Dietary Phytochemical Index (DPI) and metabolic syndrome (MetS) and its components.

Methods

This cross-sectional study focused on adults aged between 20 and 70years. The dietary intake was assessed using a validated and reliable food frequency questionnaire. DPI was calculated based on dietary energy, derived from phytochemical-rich food sources (kcal) per total daily energy intake (kcal). The odds ratio of MetS and its components were assessed across DPI quartiles by logistic regression models.

Results

After adjustment for all potential confounders, the risk of MetS (OR: 0.63, 95% CI = 0.41–0.96) and elevated blood pressure (OR: 0.62, 95% CI = 0.40–0.96) in the second category of DPI decreased significantly as compared to that in the first category. Subjects in the second and fourth quartiles of DPI with adjusting for age, sex and total energy intake revealed 30 and 25% lower risk of abdominal obesity, respectively. After full adjustment for confounders, the analysis stratified by sex showed women in the highest quartile of DPI had 59% lower risk of MetS (OR: 0.41, 95% CI = 0.22–0.76) as compared to those in the lowest quartile of DPI.

Conclusions

Greater adherence to phytochemical-rich diet could reduce odds of MetS and some components, especially in women. Further studies with intervention approaches are recommended.

The Association of Dietary Phytochemical Index with Metabolic Syndrome in Adults

In this study, we assessed the association between the dietary phytochemical index (DPI) and metabolic syndrome (MetS) among adults in a cross-sectional study. We enrolled 850 adult men and women aged 18–65 years who had been referred to health centers in Tehran, Iran. The DPI was calculated based on 8 components including fruits, vegetables, legumes, whole grains, soy products, nuts, seeds, olive, and olive oil. The odds ratio (OR) and 95% confidence interval (CI) of the MetS across quartiles of the DPI were calculated using the logistic regression analysis, adjusting for age, energy intake, marital status, education status, occupation, smoking status, physical activity, and body mass index. The mean age of participants was 44.7 ± 10.7, of whom 69% were women. The prevalence of MetS was 30.5%. The mean score of DPI in women and men was 36.2 ± 26.8 and 33.7 ± 24.7, respectively. There was no significant association between DPI and odds of MetS in men (OR_{fourth vs. first quartile},1.57; 95% CI, 0.64–3.84) and women (OR_{fourth vs. first quartile}, 0.86; 95% CI, 0.50–1.49) in the fully adjusted model. There was an inverse association between DPI and increased risk of central obesity in women (OR_{fourth vs. first quartile}, 0.54; 95% CI, 0.29–1.00; p trend = 0.03). There was no significant association between DPI and other components of the MetS in men and women. Finally, we observed no significant association between the DPI and the odds of MetS. However, the finding suggests that having a phytochemical-rich diet can be inversely associated with abdominal obesity.

The effect of an orally-dosed Caralluma Fimbriata extract on appetite control and body composition in overweight adults

To examine the effect of a Caralluma Fimbriata extract (CFE) on biomarkers of satiety and body composition in overweight adults. A double-blind, randomised, placebo controlled trial to examine the effect of a Caralluma Fimbriata extract (CFE) on biomarkers of satiety and body composition in overweight adults. Eighty-three men and women aged between 20 and 50 years of age completed 16 weeks of daily supplementation with either CFE or placebo. Plasma cardiometabolic (lipid profile, glucose, insulin) and satiety (ghrelin, leptin, neuropeptideY) biomarkers, body composition, diet history and gastrointenstinal function were assessed at baseline, weeks 4, 8, 12 and 16. Subjects in the CFE and placebo groups were well matched and predominatly female 93% and 87.5%, with a mean age of 40.9 ± 6.7 and 39.5 ± 7.5 years and body mass index (BMI) of 30.0 ± 3.1 and 30.2 ± 2.9 kg/m² respectively. There was a significant difference in plasma leptin concentration change between groups at week 16 (p = 0.04), with the placebo group increasing concentration (2.27 ± 4.80 ng/mL) while the CFE group (0.05 ± 4.69 ng/mL) remained the same. At week 16, the CFE group had significantly reduced their calorie intake from baseline compared to the placebo group (245 cal vs 15.8 cal respectively p < 0.01). The CFE group also had a significant reduction in waist circumference of 2.7 cm compared to an increase of 0.3 cm in the placebo group (p = 0.02). A weight increase from baseline was seen in the placebo group that was not observed in the CFE group (1.33 kg weight gain vs 0.37 kg weight loss respectively; p = 0.03). The placebo group also had a significant increase in fat mass, android fat mass, BMI and leptin compared to the CFE group (p = 0.04, 0.02, < 0.01 respectively). CFE was effective at maintaining bodyweight during a non-calorie controlled diet compared to a placebo. The mechanism responsible for this action is requiring further research and could be due to an increase in satiety receptor sensitivity.

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

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

Mechanisms of action for the anti-obesogenic activities of phytochemicals

The prevalence of obesity is increasing rapidly globally and has recently reached pandemic proportions. It is a multifactorial disorder linked to a number of non-communicable diseases such as type-2 diabetes, cardiovascular disease, and cancer. Over-nutrition and a sedentary lifestyle are considered the most significant causes of obesity; a healthy lifestyle and behavioural interventions are the most powerful ways to achieve successful weight loss, but to maintain this in the long term can prove difficult for many individuals, without medical intervention. Various pharmacological anti-obesogenic drugs have been tested and marketed in the past and have been moderately successful in the management of obesity, but their adverse effects on human health often outweigh the benefits. Natural products from plants, either in the form of crude extracts or purified phytochemicals, have been shown to have anti-obesogenic properties and are generally considered as nontoxic and cost-effective compared to synthetic alternatives. These plant products combat obesity by targeting the various pathways and/or regulatory functions intricately linked to obesity. Their mechanisms of action include inhibition of pancreatic lipase activities, an increase in energy expenditure, appetite regulation, lipolytic effects, and inhibition of white adipose tissue development. In this review, we discuss the distinct anti-obesogenic properties of recently reported plant extracts and specific bioactive compounds, along with their molecular mechanisms of action. This review will provide a common platform for understanding the different causes of obesity and the possible approaches to using plant products in tackling this worldwide health issue.

Anti-obesity effects of dichloromethane leaf extract of Gnidia glauca in high fat diet-induced obese rats

BACKGROUND

Obesity is a chronic metabolic disorder characterized by increased adipose tissue mass due to positive energy balance. Prescription of anti-obesity drugs can be useful adjuncts to diet and exercise for obese patients who have failed to achieve weight loss. However, these drugs are ineffective and are associated with adverse effects. In recent times, medicinal plants have drawn a sharp focus owing to their biocompatibility and effectiveness. Attempts to determine the therapeutic effects and identification of bio-active principles from herbal prescriptions have become the prime focus in the validation of their folkloric usage and in drug discovery programs. Therefore, the present study aimed to determine the anti-obesity effects of Dichloromethane leaf extract of Gnidia glauca in high-fat-diet-induced obese rats.

METHODS

Obesity was induced experimentally in white albino Wistar rats by feeding them with prepared high-fat-diet and water ad libitum for a period of 12 weeks. The in-vivo anti-obesity effects were determined by oral administration of Gnidia glauca at dosage levels of 200, 250 and 300 mg/kg body weight from the 6th to 12th week of study. Phytochemical analysis of Gnidia glauca was conducted using gas chromatography linked to mass spectrophotometer.

RESULTS

The results indicated that Gnidia glauca exhibited potent anti-obesity effects. It significantly reduced the body weight, organ weights, organo-somatic indices, anthropometric indices, the total fat content, adiposity index, atherogenic index as well as various lipid profiles. It also decreased the total feed intake. However, it significantly increased levels of high-density lipoproteins and rectal body temperature of rats. Quantitative phytochemical analysis also revealed the presence of various phytocompounds that have shown to be associated with anti-obesity effects.

CONCLUSION

The anti-obesity effects of Gnidia glauca maybe attributed to the phytochemicals present. The present study, therefore, scientifically validates the traditional use of Gnidia glauca as a potential candidate for the synthesis of new effective anti-obesity supplement.

Targeting PLIN2/PLIN5-PPARγ: Sulforaphane Disturbs the Maturation of Lipid Droplets

SCOPE

The effects of sulforaphane (SFN) on the maturation of lipid droplets (LDs)-the storage units for free fatty acids and sterols as triacylglycerides (TAG) and cholesterol esters (CE)-are far from being understood, despite the fact that SFN is known to be beneficial for ameliorating lipid metabolism disorders.

METHODS AND RESULTS

High-fat-intake models are established in both HHL-5 hepatocytes and rodents. The numbers and sizes of LDs are decreased by SFN. The accumulation of lipid core components (TAG & CE) is reduced and the expression of their key synthetases, acyl-coenzyme A: diacylglycerol acyltransferases 2 (DGAT2) and acyl-coenzyme A: cholesterol acyltransferases 1 (ACAT1), is also inhibited. Moreover, SFN decreases LD-associated protein PLIN2 and PLIN5 expression, but not that of PLIN1 and PLIN3, both in vivo and in vitro. Furthermore, over-expression of peroxisome proliferator-activated receptor gamma (PPARγ) induces the accumulation of TAG and the up-regulation of PLIN2 and PLIN5, which are not reversed by SFN. These results suggest that PPARγ may be a target of SFN in lipid metabolism.

CONCLUSION

SFN disturbs LD maturation by inhibiting the formation of the neutral lipid core and decreases PLIN2 and PLIN5 via down-regulation of PPARγ.

Association of dietary phytochemical index and mental health in women: a cross-sectional study

Previous studies have shown that unhealthy dietary patterns are among the most important modifiable risk factors in the development of mental health disorders. We examined the association of dietary phytochemical index (DPI) with symptoms of depression, anxiety and psychological distress in Iranian women. In this cross-sectional study, a total of 488 women aged 20–50 years old attending health centres in the south of Tehran in 2018 were included. A validated and reliable FFQ was used for dietary assessment. Symptoms of depression, anxiety and psychological distress were assessed using a validated depression, anxiety, stress scales questionnaires with twenty-one-items. DPI was estimated using the following formula: (daily energy derived from phytochemical-rich foods (kJ)/total daily energy intake (kJ))×100. The mean age of the study participants was 31·9 (sd7·7) years. The prevalence of depressive symptoms, anxiety and psychological distress among study participants was 34·6, 40·6 and 42·4 %, respectively. After controlling for potential confounders, women in the highest tertile of DPI had a lower prevalence of depressive symptoms (OR 0·22; 95 % CI 0·12, 0·38) and anxiety (OR 0·33; 95 % CI 0·20, 0·55), as well as psychological distress (OR 0·30; 95 % CI 0·18, 0·49) compared with those in the lowest tertile. In conclusion, we found a significant association between DPI and mental health in women. Prospective studies are needed to confirm these findings.

Six types of tea reduce high-fat-diet-induced fat accumulation in mice by increasing lipid metabolism and suppressing inflammation

A high-fat diet results in obesity because of white fat accumulation.

Role of obesity in smoking behaviour: Mendelian randomisation study in UK Biobank

OBJECTIVE

To determine whether body mass index, body fat percentage, and waist circumference influence smoking status and intensity.

DESIGN

Mendelian randomisation study.

SETTING

UK Biobank, with replication of results from the Tobacco and Genetics (TAG) consortium.

PARTICIPANTS

European descent participants from the UK Biobank cohort (n=372 791) and the TAG consortium (n=74 035).

MAIN OUTCOME MEASURES

Risk of current and past smoking, number of cigarettes smoked per day, age of smoking initiation.

RESULTS

The Mendelian randomisation analysis indicated that each standard deviation increment in body mass index (4.6) increased the risk of being a smoker (odds ratio 1.18 (95% confidence interval 1.13 to 1.23), P<0.001). This association was replicated in the TAG consortium data (1.19 (1.06 to 1.33), P=0.003). Furthermore, each standard deviation increment in body mass index was estimated to increase smoking intensity by 0.88 cigarettes per day (95% confidence interval 0.50 to 1.26, P<0.001) in UK Biobank and 1.27 cigarettes per day in the TAG consortium (0.46 to 2.07, P=0.002). Similar results were also seen for body fat percentage and waist circumference in both UK Biobank and the TAG consortium data.

CONCLUSIONS

These results strongly suggest that higher adiposity influences smoking behaviour and could have implications for the implementation of public health interventions aiming to reduce the prevalence of these important risk factors.

Black pepper-based beverage induced appetite-suppressing effects without altering postprandial glycaemia, gut and thyroid hormones or gastrointestinal well-being: a randomized crossover study in healthy subjects

Pleiotropic effects of spices on health, particularly on glucose metabolism and energy regulation, deserve further clinical investigation into their efficacy.

Duodenal and ileal glucose infusions differentially alter gastrointestinal peptides, appetite response, and food intake: a tube feeding study

Background: Activation of the ileal brake through the delivery of nutrients into the distal small intestine to promote satiety and suppress food intake provides a new target for weight loss. Evidence is limited, with support from naso-ileal lipid infusion studies.Objective: The objective of the study was to investigate whether glucose infused into the duodenum and ileum differentially alters appetite response, food intake, and secretion of satiety-related gastrointestinal peptides.Design: Fourteen healthy male participants were randomly assigned to a blinded 4-treatment crossover, with each treatment of single-day duration. On the day before the intervention (day 0), a 380-cm multilumen tube (1.75-mm diameter) with independent port access to the duodenum and ileum was inserted, and position was confirmed by X-ray. Subsequently (days 1-4), a standardized breakfast meal was followed midmorning by a 90-min infusion of isotonic glucose (15 g, 235 kJ) or saline to the duodenum or ileum. Appetite ratings were assessed with the use of visual analog scales (VASs), blood samples collected, and ad libitum energy intake (EI) measured at lunch, afternoon snack, and dinner.Results: Thirteen participants completed the 4 infusion days. There was a significant effect of nutrient infused and site (treatment × time, P < 0.05) such that glucose-to-ileum altered VAS-rated fullness, satisfaction, and thoughts of food compared with saline-to-ileum (Tukey's post hoc, P < 0.05); decreased ad libitum EI at lunch compared with glucose-to-duodenum [-22%, -988 ± 379 kJ (mean ± SEM), Tukey's post hoc, P < 0.05]; and increased glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) compared with all other treatments (Tukey's post hoc, P < 0.05).Conclusions: Macronutrient delivery to the proximal and distal small intestine elicits different outcomes. Glucose infusion to the ileum increased GLP-1 and PYY secretion, suppressed aspects of VAS-rated appetite, and decreased ad libitum EI at a subsequent meal. Although glucose to the duodenum also suppressed appetite ratings, eating behavior was not altered. This trial was registered at www.anzctr.org.au as ACTRN12612000429853.

Combined Effects of Phytochemicals and Exercise on Fatty Acid Oxidation

[Purpose]

The purpose of this review is to discuss current views regarding the acute effects of phytochemicals, exercise, and exercise plus phytochemicals on fatty acid oxidation.

[Methods]

Data acquired from human and animal studies were comprehensively assessed to determine the single and combined effects of phytochemicals and exercise on fatty acid oxidation. In addition, underlying mechanisms associated with those conditions that may contribute to the regulation of fat metabolism are discussed.

[Results]

Although not all phytochemicals are effective at increasing fatty acid oxidation, some significantly improve the rate of fatty acid oxidation at rest. In addition, dietary supplementation of p-synephrine, catechins, or anthocyanins in combination with moderately intense exercise has the additive effect of increasing fatty acid oxidation, but not total energy expenditure during exercise.

[Conclusion]

The data reported from current reviewed studies suggest positive outcomes regarding facilitation of fatty acid oxidation from the combined effects of certain phytochemicals with exercise. Those data provide new insight for developing a strategy to boost fat loss and control weight in obese patients.

Dietary phytochemical index and the risk of insulin resistance and β-cell dysfunction: a prospective approach in Tehran lipid and glucose study

BACKGROUND

In this study, we aimed to investigate the association of dietary phytochemical index (DPI) with insulin resistance, β-cell dysfunction, and insulin sensitivity.

METHODS

This longitudinal study was conducted on 1141 participants of the Tehran Lipid and Glucose Study. Dietary data were collected using a validated semi-quantitative FFQ with 168 food items at baseline and DPI was calculated. Fasting serum insulin and glucose were measured at baseline and again after a 3-year of follow-up.

RESULTS

After 3-years of follow-up, the risk of hyperinsulinemia significantly decreased by 65 (OR = 0.35, 95% CI = 0.21-0.60) and 86% (OR = 0.14, 0.07-0.29), in the third and fourth quartile categories of DPI, respectively. The occurrence of insulin resistance and insulin insensitivity in participants with higher DPI was significantly lower than the others (OR = 0.48, 95% CI = 0.25-0.93 and OR = 0.11, 95% CI = 0.05-0.24, respectively).

CONCLUSION

Higher consumption of phytochemical-rich foods may have protective effects against development of insulin resistance.

Association between high consumption of phytochemical-rich foods and anthropometric measures: a systematic review

Phytochemical-rich foods consumption may be a valid nutritional strategy to reduce the risk of weight gain and obesity. The phytochemical index (PI) is a simple and nonspecific method to evaluate the phytochemical intake, defined as the percentage of dietary calories derived from foods rich in phytochemicals. We aimed to conduct a systematic review to evaluate whether high consumption of phytochemical-rich foods evaluated by the PI is associated with lower values of anthropometric measurements. The available literature suggests that the PI seems to be inversely associated with body weight and waist circumference. Analyzing the longitudinal changes in anthropometric variables, individuals with high intake of phytochemicals gained less weight and fat mass when compared to those with lower PI. Our findings suggest that higher PI is associated with lower body mass index, waist circumference and adiposity. Whether the results are a reflex of a lower calorie intake or the anti-obesity properties of phytochemicals remains to be elucidated.

Aqueous Extract of Allium sativum (Linn.) Bulbs Ameliorated Pituitary-Testicular Injury and Dysfunction in Wistar Rats with Pb-Induced Reproductive Disturbances

AIM

To determine the effects of aqueous extract of Allium sativum bulbs (AEASAB) on pituitary-testicular injury and dysfunction in Wistar rats with lead-induced reproductive disturbances.

MATERIALS AND METHODS

Male Wistar rats were divided into 7 groups such that the control group received propylene glycol at 0.2 ml/100 g intraperitoneally for 10 consecutive days, the toxic group received lead (Pb) alone at 15 mg/kg/day via intraperitoneal route for 10 days while the treatment groups were pretreated with lead as the toxic group after which they received graded doses of the extract at 50, 100 and 200 mg/kg/day via oral route for 28 days.

RESULTS

Pb administration induced significant deleterious alterations in the antioxidant status of the brain and testis, sperm characterization (counts, motility and viability) as well as reproductive hormones (FSH, LH and testosterone) of exposed rats (p < 0.05). These were significantly reversed in the AEASAB-treated groups (p < 0.05). Also, there was marked improvement in the Pb-induced vascular congestion and cellular loss in the pituitary while the observed Pb-induced severe testicular vacuolation was significantly reversed in the representative photomicrographs, following administration of the extract.

CONCLUSION

AEASAB treatment ameliorated the pituitary-testicular injury and dysfunction in Wistar rats with Pb-Induced reproductive disturbances.

Association between body composition and khat chewing in Ethiopian adults

BACKGROUND

Khat (Catha edulis Forsk) is a psychostimulant herb widely cultivated and used in Ethiopia. The link between khat use and body composition is little known.

OBJECTIVE

The aim was to determine the association between body composition and khat use.

METHODS

We recruited 415 individuals 18-78 years of age from Jimma Town. Sociodemographic and lifestyle data were collected using structured questionnaires. Fat mass (FM, kg) and fat-free mass (FFM, kg) were estimated from whole-body bio impedance. Weight (kg), FM and FFM were indexed to height (m) as BMI (kg/m(2)), fat mass index (FMI) (kg/m) and fat-free mass index (FFMI) (kg/m), respectively. Independent predictors of BMI, FMI and FFMI were identified using regression analysis.

RESULT

Participants' mean ± SD of age was 37 ± 13 years and 205 (53.2 %) were males. Mean ± SD of BMI, FMI and FFMI were 21.0 kg/m(2) ± 4.1, 6.8 kg/m ± 5.2 and 27.9 kg/m ± 3.8, respectively. Multivariable model showed that, compared with non-chewers, khat chewers had a lower BMI (B = -1.56, 95 % CI -0.78, -2.33) and FMI (B = 2.19, 95 % CI -1.32, -3.06). FMI was lower in cigarette smokers than non-smokers by -1.36 kg/m (95 % CI -0.23, -2.49). Concurrently, khat and cigarette users increased FMI by 2.78 (95 % CI 0.11, 5.44). FFMI decreased with age (B = -0.02, 95 % CI -0.05, -0.002).

CONCLUSION

FMI and BMI were lower in khat users than non-users, but there was no difference in lean mass. The consequence of this body composition change should be investigated.

Association between dietary phytochemical index and 3-year changes in weight, waist circumference and body adiposity index in adults: Tehran Lipid and Glucose study

Background

High intakes of phytochemical-rich foods have favorable effects on the prevention of chronic diseases. In this study we assessed the dietary phytochemical index (PI) in relation to 3-year change in weight, waist circumference (WC), body adiposity index (BAI) among Tehranian adults.

Methods

This longitudinal study was conducted in the framework of Tehran Lipid and Glucose Study, between 2006–2008 and 2009–2011, on 1938 adults, aged 19–70 y. The usual intake of participants was measured at baseline using a validated semi-quantitative food frequency questionnaire and dietary PI was calculated. Anthropometric measures were assessed both at baseline and 3 years later. Multiple regression models were used to estimate mean difference changes in anthropometrics associated with various dietary PI.

Results

The mean age of participants was 40.4 ± 13.0 y, at baseline, respectively. Mean weight gain was 1.49 ± 5.06 kg (1.65 ± 5.3 kg in men and 1.34 ± 4.9 kg in women) during 3-year period. After adjustment for potential confounding variables including age at baseline, sex, BMI, educational levels, smoking, physical activity, total energy intake, dietary intake of carbohydrate, fat and protein, dietary intakes of whole grains in the highest quartile category of PI were inversely associated with 3-year changes in weight and WC (P for trend <0.05). Dietary intake of fruits in the highest quartile was also associated with lower weight gain during the study period (P for trend <0.05). There was significant inverse association between the highest quartile category of dietary PI with the 3-year changes in weight and BAI (P for trend <0.05).

Conclusion

Higher dietary PI could have favorable effects on prevention of weight gain and reduction of body adiposity in adults.