SUMMARY: This review assesses the accumulated evidences on the mutual influence of monoamines, hormones and neuropeptides that are linked to obesity. A few anti-obesity drugs that exert their mechanisms of action through monoamines are briefly discussed to support the notion of monoamines being a critical target of drug discovery for new anti-obesity drugs. Subsequently, the review provides a comprehensive overview of central dopamine and serotonin changes that are associated with the use of khat or its alkaloids. Then, all the studies on khat that describe physical, biochemical and hormonal changes are summarised and discussed in depth.
CONCLUSION: The reviewed studies provide relatively acceptable evidence that different khat extracts or cathinone produces changes in terms of weight, fat mass, appetite, lipid biochemistry and hormonal levels. These changes are more pronounced at higher doses and long durations of intervention. The most suggested mechanism of these changes is the central action that produces changes in the physiology of dopamine and serotonin. Nonetheless, there are a number of variations in the study design, including species, doses and durations of intervention, which makes it difficult to arrive at a final conclusion about khat regarding obesity, and further studies are necessary in the future to overcome these limitations.
METHODS: We designed a comprehensive assessment system to evaluate the safety, authenticity according to label claim, and pharmaceutical quality of slimming nutraceuticals. Six different popular products were evaluated (Zotreem Plus®, Zotreem Extra®, Malaysian Super Slim®, AB Slim®, Chinese Super Slim®, and Metabolites®). The pharmaceutical evaluation included analyzing the samples via high-performance liquid chromatography to determine any possible adulterants. Additionally, the products' physical properties were assessed via pharmacopeial tests. Finally, a microbial evaluation and a cross-sectional observational retrospective prevalence study were conducted to assess the products' safety and efficacy. -Results: The tested products were found to be adulterated with unreported active pharmaceutical ingredients such as sibutramine, sildenafil, phenolphthalein, and orlistat. Furthermore, they contained heterogeneous amounts of adulterants and exhibited an unsatisfactory pharmaceutical and microbial quality. Finally, the observational survey conducted on users showed that high percentages of participants suffered from common side effects such as depression, diarrhea, and hypertension.
CONCLUSIONS: These products threaten the health of consumers. There is a need to raise awareness of the lethal consequences of illegal nutraceuticals.
METHODS: In a parallel, single-blind and placebo-controlled study, 22 healthy overweight and obese volunteers were randomly allocated to receive 30 g day(-1) oligofructose or cellulose for 6 weeks following a 2-week run-in. Subjective appetite and side effect scores, breath hydrogen, serum short chain fatty acids (SCFAs), plasma gut hormones, glucose and insulin concentrations, EI, BW and adiposity were quantified at baseline and post-supplementation.
RESULTS: Oligofructose increased breath hydrogen (P