Current and novel approaches to the drug therapy of obesity

Carbonic anhydrases: Moiety appended derivatives, medicinal and pharmacological implications

In the realm of enzymology, Carbonic anhydrase (CA) emerges as a pivotal protagonist orchestrating the rapid conversion of carbon dioxide and water into bicarbonate ions and hydrogen ions, respectively. Carbonic anhydrase inhibitors (CAIs) are the class of drugs that target various isoforms of the enzyme, and these inhibitors play a crucial role in the treatment and management of multiple diseases such as cancer, glaucoma, high altitude sickness, rheumatoid arthritis, obesity, epilepsy, and sleep apnea. Several structural classes of CAIs developed till date possess unique architects of the pharmacophoric requirements around the central core moiety for the selective targeting of various isoforms of the CA. Recent advancements in drug design and development, along with technologies that aid in structure determination, have led to the development of several isoform-selective inhibitors of CA enzymes. However, their clinical development was hampered by the lack of desired therapeutic efficacy, isoform selectivity and safety profile. This review covers the most recent approaches used by different researchers concerned with the development of isoform-selective carbonic anhydrase inhibitors belonging to distinct structural classes like sulphonamides, carbazoles, selenols, coumarin, organotelluride, topiramate, thiophene, triazole, uracil-modified benzylic amines, and thiourea etc. In addition, their structure-activity relationships, biological evaluation, and in silico studies inlcuding the forthcoming avenues of advancements have been discussed. This review serves as a valuable resource for developing potent and efficacious CAIs with remarkable therapeutic implications; offering insights into their potency, specificity, and potential clinical applications.

Interplay of atherogenic factors, protein intake and betatrophin levels in obese-metabolic syndrome patients treated with hypocaloric diets

CONTEXT

The understanding of the potential role of betatrophin in human metabolic disorders is a current challenge.

OBJECTIVE

The present research evaluated circulating betatrophin levels in obese patients with metabolic syndrome (MetSyn) features under energy-restricted weight-loss programs and in normal weight in order to establish the putative interplay between the levels of this hormone, diet and metabolic risk factors linked to obesity and associated comorbidities.

SUBJECTS AND METHODS

One hundred forty-three participants were enrolled in the study (95 obese-MetSyn; age 49.5±9.4 years; body mass index (BMI) 35.7±4.5 kg m(-2) and 48 normal weight; age 35.71±8.8 years; BMI 22.9±2.2 kg m(-2)). A nutritional therapy consisting in two hypocaloric strategies (control diet based on the AHA recommendations and the RESMENA (MEtabolic Syndrome REduction in Navarra) diet, a novel dietary program with changes in the macronutrient distribution) was only prescribed to obese-MetSyn participants who were randomly allocated to the dietary strategies. Dietary records, anthropometrical and biochemical variables as well as betatrophin levels were analyzed before (pre-intervention, week 0), at 8 weeks (post-intervention, week 8) and after 4 additional months of self-control period (follow-up, week 24).

RESULTS

Betatrophin levels were higher in obese-MetSyn patients than normal-weight subjects (1.24±0.43 vs 0.97±0.69 ng ml(-1), respectively, P=0.012), and levels were positively associated with body composition, metabolic parameters, leptin and irisin in all participants at baseline. Notably, low pre-intervention (week 0) betatrophin levels in obese patients were significantly associated with higher dietary-induced changes in atherogenic risk factors after 8 weeks. Moreover, protein intake, especially proteins from animal sources, was an independent determinant of betatrophin levels after dietary treatment (B=-0.27; P=0.012).

CONCLUSIONS

Betatrophin is elevated in obese patients with MetSyn features and is associated with poorer nutritional outcomes of adiposity and dyslipidemia traits after a weight-loss program. Dietary protein intake could be a relevant modulator of betatrophin secretion and activity.

Biomarkers and insulin sensitivity in women with Polycystic Ovary Syndrome: Characteristics and predictive capacity

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a common endocrine disorder associated with metabolic complications. Metabolic biomarkers with roles in obesity, glycaemic control and lipid metabolism are potentially relevant in PCOS. The aim was to investigate metabolic biomarkers in lean and overweight women with and without PCOS and to determine whether any biomarker was able to predict insulin resistance in PCOS.

DESIGN

Cross-sectional study.

PATIENTS

Eighty-four women (22 overweight and 22 lean women with PCOS, 18 overweight and 22 lean women without PCOS) were recruited from the community and categorized based on PCOS and BMI status.

MEASUREMENTS

Primary outcomes were metabolic biomarkers [ghrelin, resistin, visfatin, glucagon-like peptide-1 (GLP-1), leptin, plasminogen activator inhibitor -1 (PAI-1), glucose-dependent insulinotropic polypeptide (GIP) and C-Peptide] measured using the Bio-Plex Pro Diabetes assay and insulin sensitivity as assessed by glucose infusion rate on euglycaemic-hyperinsulinaemic clamp.

RESULTS

The biomarkers C-peptide, leptin, ghrelin and visfatin were different between overweight and lean women, irrespective of PCOS status. The concentration of circulating biomarkers did not differ between women with PCOS diagnosed by the Rotterdam criteria or National Institute of Health criteria. PAI-1 was the only biomarker that significantly predicted insulin resistance in both control women (P = 0.04) and women with PCOS (P = 0.01).

CONCLUSIONS

Biomarkers associated with metabolic diseases appear more strongly associated with obesity rather than PCOS status. PAI-1 may also be a novel independent biomarker and predictor of insulin resistance in women with and without PCOS.

Longitudinal variation of circulating irisin after an energy restriction-induced weight loss and following weight regain in obese men and women

OBJECTIVE

The recently discovered peptide irisin has been hypothesized to be a regulator of body metabolism. The objective of this work was to evaluate whether circulating human irisin levels are modulated by body size and changes in adiposity during an energy restriction treatment and the subsequent weight regain.

METHODS

A group of 94 obese patients (50 men, 44 women; 49.4 ± 9.4 years; BMI 35.6 ± 4.5 kg/m(2) ) participated in a weight loss program following an 8-week hypocaloric diet (-30% energy expenditure) with a weight maintenance follow-up. The patients were evaluated at 0, 8, and 24 weeks after starting treatment. In addition, 48 normal-weight subjects (16 men, 32 women; 35.71 ± 8.8 years; BMI 22.9 ± 2.2 kg/m(2) ) participated as controls. Plasma irisin, body weight, body composition, and hormones controlling energy homeostasis were measured.

RESULTS

Irisin levels were higher in obese subjects (353.1 ± 18.6 ng/mL) than in those of normal-weight (198.4 ± 7.8 ng/mL; P ≤ 0.001) and were also higher in men (340.9 ± 20 ng/mL) than in women (267.6 ± 12 ng/mL; P < 0.05). Moreover, irisin plasma levels were significantly correlated with high levels of direct and indirect adiposity markers, such as weight, BMI, waist circumference, and fat mass, as measured by bioimpedance, but not with height or leptin levels. Interestingly, irisin levels paralleled body weight reduction after the dietary treatment (week 8) and again returned to the baseline levels at 24 weeks in those patients regaining the lost weight.

CONCLUSIONS

Irisin strongly reflects body fat mass, suggesting that the irisin circulating levels are conditioned by adiposity level.

Contemporary approaches to adult obesity treatment

Adult obesity is a common health problem associated with significant adverse health outcomes. Evidence-based guidelines support intensive nutrition and behavioral counseling and moderate physical exercise. Pharmacotherapy agents are available for long-term use to enhance weight loss efforts for some patients.

Winning a won game: caffeine panacea for obesity syndemic

Over the past decades, chronic sleep reduction and a concurrent development of obesity have been recognized as a common problem in the industrialized world. Among its numerous untoward effects, there is a possibility that insomnia is also a major contributor to obesity. This attribution poses a problem for caffeine, an inexpensive, “natural” agent that is purported to improve a number of conditions and is often indicated in a long-term pharmacotherapy in the context of weight management. The present study used the “common target” approach by exploring the tentative shared molecular networks of insomnia and adiposity. It discusses caffeine targets beyond those associated with adenosine signaling machinery, phosphodiesterases, and calcium release channels. Here, we provide a view suggesting that caffeine could exert some of its effects by acting on several signaling complexes composed of HIF-1α/VEGF/IL-8 along with NO, TNF-α, IL1, and GHRH, among others. Although the relevance of these targets to the reported therapeutic effects of caffeine has remained difficult to assess, the utilization of caffeine efficacies and potencies recommend its repurposing for development of novel therapeutic approaches. Among indications mentioned, are neuroprotective, nootropic, antioxidant, proliferative, anti-fibrotic, and anti-angiogenic that appear under a variety of dissimilar diagnostic labels comorbid with obesity. In the absence of safe and efficacious antiobesity agents, caffeine remains an attractive adjuvant.

Molecular network of obesity: what does it promise for pharmacotherapy?

There is growing evidence that receptors that respond to orexigenic and anorexigenic signals of respective neuropeptides are also implicated in cognitive, emotional, sensory and motor functions. How do these signals trigger a particular appetitive function while also acting in so different contexts in controlling non-appetitive behaviours? This perspective seeks an answer in their peculiar modular organization when each module planted in complex networks controlling appetite is also engaged in different domains. Network analysis may be essential in considering pharmacotherapeutic interventions and, in particular, when anticipating untoward central effects of agents explored from a therapeutic point of view.

Management of Obesity in Patients with Peripheral Arterial Disease

Obesity is a major risk factor for cardiovascular disorders, including peripheral arterial disease. This review outlines the evidence for a 6-step process for the management of obesity, starting with identifying the degree and type of obesity, followed by target setting, life style and behavioural changes, imposed hypocaloric diet and physical activity, pharmacological treatment and consideration of eating disorders and/or bariatric surgery.