Effects of CYP3A5, CYP2C19, and CYP2B6 on the clinical efficacy and adverse outcomes of sibutramine therapy: A crucial role for the CYP2B6*6 allele

Potential health risks of foodborne performance-enhancing drugs in competitive sports

Athletes need to consume a significant amount of energy during prolonged training and in high-intensity competition. It is necessary for them to take nutritional foods that recharge their bodies. However, in sporting events of recent years, both domestic and international, many positive drug tests are found to be caused by the ingestion of foods that contain performance-enhancing drugs (PEDs). As a result, the prevention and control of PEDs in food supply have drawn increasing attention. For better prevention and control, the first step is to understand the food contaminants -- PEDs. This study has categorized PEDs through their presence in animal-derived foods, plant-derived foods, and synthetic nutritional supplements in competitive sports. It investigates the potential risks of foodborne doping using techniques such as external addition and endogenous component analysis. This research explored the causes of PEDs in food and their negative effects on athletes and proposed measures to ensure the safety of nutritional substances in competitive sports. PEDs in animal-derived foods include β-adrenergic agonists, anabolic steroids, and glucocorticoids, which can be found in meat and ox penis, amongst other food sources. In contrast, PEDs in plant-derived foods include alkaloids, higenamine, and zeranol, which can be found in coffee, tea, Sichuan pepper, custard apple, and cereal. Performance-enhancing drugs (PEDs) that are often added to synthetic supplements include creatine, traditional Chinese herbs, 1, 3-dimethylbutylamine (DMAA), sibutramine, ephedrine, and methylhexanamine. Targeted anti-doping training should be provided to athletes. In addition, the latest domestic and international standards and regulations regarding PEDs or prohibited and restricted ingredients in foods should be tracked in real-time. The control list for performance-enhancing drugs in food should be continually updated and refined. Research on detection methods for performance-enhancing drugs in food should also be advanced. Moreover, market surveillance and law enforcement should be strengthened to ensure that sports foods meet national safety standards before they enter the market. This paper provides workable solutions to clarify the types and scope of performance-enhancing drugs in food, aiming to improve the prevention and control of PEDs in animal-derived foods, plant-derived foods, and supplements in major sporting events.

The Niche of n-of-1 Trials in Precision Medicine for Weight Loss and Obesity Treatment: Back to the Future

PURPOSE OF REVIEW

The n-of-1 clinical trials are considered the epitome of individualized health care. They are employed to address differences in treatment response and adverse events between patients, in a comparative effectiveness manner, extending beyond the delivery of horizontal recommendations for all.

RECENT FINDINGS

The n-of-1 design has been applied to deliver precision exercise interventions, through eHealth and mHealth technologies. Regarding personalized and precision medical nutrition therapy, few trials have implemented dietary manipulations and one series of n-of-1 trials has applied comprehensive genetic data to improve body weight. With regard to anti-obesity medication, pharmacogenetic data could be applied using the n-of-1 trial design, although none have been implemented yet. The n-of-1 clinical trials consist of the only tool for the delivery of evidence-based, personalized obesity treatment (lifestyle and pharmacotherapy), reducing non-responders, while tailoring the best intervention to each patient, through "trial and error". Their application is expected to improve obesity treatment and mitigate the epidemic.

One Hundred Faces of Geraniol

Geraniol is a monoterpenic alcohol with a pleasant rose-like aroma, known as an important ingredient in many essential oils, and is used commercially as a fragrance compound in cosmetic and household products. However, geraniol has a number of biological activities, such as antioxidant and anti-inflammatory properties. In addition, numerous in vitro and in vivo studies have shown the activity of geraniol against prostate, bowel, liver, kidney and skin cancer. It can induce apoptosis and increase the expression of proapoptotic proteins. The synergy of this with other drugs may further increase the range of chemotherapeutic agents. The antibacterial activity of this compound was also observed on respiratory pathogens, skin and food-derived strains. This review discusses some of the most important uses of geraniol.

Effects of CYP2D6 and CYP3A5 genetic polymorphisms on steady-state pharmacokinetics and hemodynamic effects of tamsulosin in humans

PURPOSE

Tamsulosin is one of the most potent drugs currently available to treat benign prostatic hyperplasia. Cytochrome P450 (CYP) 2D6 and CYP3A are the two major enzymes responsible for tamsulosin metabolism. The purpose of this study was to evaluate the effects of CYP2D6 and CYP3A5 genetic polymorphisms on the pharmacokinetics and hemodynamic effects of tamsulosin in humans.

METHODS

Twenty-nine male subjects were enrolled and their CYP2D6 (*2,*4,*5,*10,*14,*21,*41, and *xN) and CYP3A5 (*5) genotypes were screened. Tamsulosin was administered daily for 6 days to assess its steady-state pharmacokinetics and hemodynamic effects according to CYP2D6 and CYP3A5 genotypes.

RESULTS

CYP2D6 group 3 (with genotype *10/*10 or *5/*10) exhibited higher plasma levels than CYP2D6 group 1 (with genotype *1/*1,*1/*2,*1/*2xN, or *2/*10xN) or CYP2D6 group 2 (with genotype *1/*10,*1/*41, or *2/*5) (trough concentrations for groups 1, 2, and 3: 1.3, 1.8, and 3.8 ng/mL, respectively [P < 0.001]; peak concentrations for groups 1, 2, 3: 8.3, 10.0, and 13.8 ng/mL, respectively [P < 0.005]). Similarly, CYP2D6 genotypes influenced the hemodynamic effects of tamsulosin based on systolic and diastolic blood pressures. However, the CYP3A5*3 polymorphism did not affect tamsulosin plasma levels and its hemodynamic effects.

CONCLUSION

The CYP2D6 but not the CYP3A5 genetic polymorphisms affected the pharmacokinetics and the hemodynamic effects of tamsulosin.

Sibutramine, a serotonin-norepinephrine reuptake inhibitor, causes fibrosis in rats

Sibutramine hydrochloride monohydrate is a weight loss agent indicated for the treatment of obesity. Although it has been banned from most markets, studies are still relevant as it is often a hidden ingredient in herbal and over the counter slimming products. Sibutramine induces liver fibrosis with steatosis in female Sprague-Dawley rats fed a high-energy diet without significant weight gain. In this study, using the same animal model, the effect of Sibutramine on lung morphology was investigated using histological evaluation of the terminal bronchiole and transmission electron microscopy evaluation of the respiratory tissue. From these results Sibutramine was found to induce lung fibrosis in Sprague-Dawley rats as increased collagen synthesis, mast cell accumulation and aggregates of Bronchus Associated Lymphoid Tissue (BALT) in the terminal bronchiole as well as increased collagen deposition in the respiratory tissue was seen.

Associations between the GNB3 C825T polymorphism and obesity-related metabolic risk factors in Korean obese women

PURPOSE

It is important to identify a 'metabolically unhealthy obese' subset with higher cardiovascular risk among obese individuals. We investigated the associations between the GNB3 C825T polymorphism and obesity-related metabolic risk factors among Korean obese women.

METHODS

This study was a sub-investigation of a double-blind randomized controlled trial that examined the additive effect of or list at on weight loss with sibutramine. A sample of 111 obese women were divided into T-carriers (CT/TT) or a homozygous CC group, according to the presence of the 825T allele at GNB3. These groups were compared to determine their associations with obesity-related metabolic risk factors, i.e., fasting plasma glucose, serum lipids, serum insulin/insulin resistance, and abdominal fat amounts.

RESULTS

The allele frequencies of the GNB3 polymorphism were C allele = 59.5% and T allele = 40.5%. The T allele was found to be significantly associated with greater visceral fat and higher serum lipids, and these significances remained robust after adjusting for potential covariates.

CONCLUSIONS

The GNB3 825T polymorphism is significantly associated with greater visceral fat and higher serum lipids in Korean obese women and it suggests that the GNB3 C825T is a determinant of obesity-related metabolic traits in this population.

Enantioselective N-demethylation and hydroxylation of sibutramine in human liver microsomes and recombinant cytochrome p-450 isoforms

The enantioselective metabolism of sibutramine was examined using human liver microsomes (HLM) and recombinant cytochrome P-450 (CYP) isoforms. This drug is metabolized to N-mono-desmethyl- (M1) and N,N-di-desmethylsibutramine (M2), and subsequent hydroxylation results in hydroxyl M1 (HM1) and hydroxyl M2 (HM2). No significant difference was noted in formation of M1from sibutramine between R- and S-sibutramine in HLM. However, S-enantiomers of M1 and M2 were preferentially metabolized to M2, HM1, and HM2compared to R-enantiomers in HLM, and intrinsic clearance (Clint) ratios of S-enantiomers/R-enantiomers were 1.97, 4.83, and 9.94 for M2, HM1, and HM2, respectively. CYP3A4 and CYP3A5 were only involved in the formation of M1, whereas CYP2B6 and CYP2C19 were responsible for all metabolic reactions of sibutramine. CYP2C19 and CYP3A5 displayed catalytic preference for S-sibutramine to S-M1, whereas CYP2B6 and CYP3A4 showed little or no stereoselectivity in metabolism of sibutramine to M1. In the case of M2 formation, CYP2B6 metabolized S-M1 more rapidly than R-M1 with a Clint ratio of 2.14. However, CYP2C19 catalyzed less S-M1 than R-M1 and the Clint ratio of S-M1 to R-M1 was 0.65. The most significant enantioselectivity was observed in formation of HM1 from M1, and HM2 from M2. CYP2B6 and CYP2C19 exhibited preferential catalysis of formation of hydroxyl metabolites from S-enantiomers rather than R-enantiomers. These results indicate that S-sibutramine was more rapidly metabolized by CYP isoforms than R-sibutramine, and that enantioselective metabolism needs to be considered in drug interactions involving sibutramine and co-administered drugs.