Metformin: the hidden chronicles of a magic drug

Presurgical trial of metformin in overweight and obese patients with newly diagnosed breast cancer

INTRODUCTION

We conducted a presurgical trial to assess the tissue-related effects of metformin in overweight/obese breast cancer (BC) patients.

METHODS

Metformin 1,500 mg daily was administered to 35 nondiabetics with stage 0-III BC, body mass index (BMI) ≥ 25 kg/m(2). The primary endpoint was tumor proliferation change (i.e., ki-67). Tumor proliferation change was compared to untreated historical controls, matched by age, BMI, and stage.

RESULTS

There was no reduction in ln(ki-67) after metformin (p = .98) or compared to controls (p = .47). There was a significant reduction in BMI, cholesterol, and leptin.

CONCLUSION

Despite no proliferation changes, we observed reductions in other relevant biomarkers.

Natural compounds with anti-ageing activity

Ageing is a complex molecular process driven by diverse molecular pathways and biochemical events that are promoted by both environmental and genetic factors. Specifically, ageing is defined as a time-dependent decline of functional capacity and stress resistance, associated with increased chance of morbidity and mortality. These effects relate to age-related gradual accumulation of stressors that result in increasingly damaged biomolecules which eventually compromise cellular homeostasis. Nevertheless, the findings that genetic or diet interventions can increase lifespan in evolutionarily diverse organisms indicate that mortality can be postponed. Natural compounds represent an extraordinary inventory of high diversity structural scaffolds that can offer promising candidate chemical entities in the major healthcare challenge of increasing health span and/or delaying ageing. Herein, those natural compounds (either pure forms or extracts) that have been found to delay cellular senescence or in vivo ageing will be critically reviewed and summarized according to affected cellular signalling pathways. Moreover, the chemical structures of the identified natural compounds along with the profile of extracts related to their bioactive components will be presented and discussed. Finally, novel potential molecular targets for screening natural compounds for anti-ageing activity, as well as the idea that anti-ageing interventions represent a systemic approach that is also effective against age-related diseases will be discussed.

The growing prevalence of type 2 diabetes: increased incidence or improved survival?

Approximately 347 million persons were estimated to have diabetes worldwide in 2008, an increase of 194 million cases from 1980. Diabetes now affects both high- and low-income countries, with low-income countries bearing the majority of the burden. The epidemiologic transition from traditional health risks, such as poor hygiene, to modern health risks, such as sedentary lifestyle, has facilitated the increase in incidence in diabetes, especially in developing countries. The effect of these risk factors may be especially pronounced in some racial and ethnic populations. Increased surveillance for diabetes has contributed to increased diabetes prevalence in higher-income countries. Survival with and some risk factors for diabetes have improved in developed countries, but global diabetes mortality has increased by 20 % since 1990. Population growth and aging will only increase the burden of diabetes, and public health interventions are needed to address diabetes risk factors to stem the tide of this epidemic.

Aging-associated reductions in lipolytic and mitochondrial proteins in mouse adipose tissue are not rescued by metformin treatment

Mitochondrial enzyme expression is reduced in adipose tissue from old mice, yet little is known regarding mechanisms that could be mediating, or interventions that could be used, to reverse these changes. The purpose of this study was to examine the relationship between lipolytic and fatty acid reesterification enzymes, 5' adenosine monophosphate-activated protein kinase and mitochondrial proteins in adipose tissue from young versus old mice. A second aim was to determine whether metformin treatment could rescue the age-associated decline in adipose tissue mitochondrial proteins. Approximately 22-month-old male C57BL/6 mice were fed a diet with or without 0.5% metformin for 8 weeks. Compared with young mice (~11 wk of age), the protein content/phosphorylation of hormone-sensitive lipase, adipose tissue triglyceride lipase, and phosphoenolpyruvate carboxykinase were reduced in old mice. This was paralleled by increases in the plasma nonesterified fatty acid:glycerol ratio and reductions in adipose tissue 5' adenosine monophosphate-activated protein kinase activity and select mitochondrial proteins in old mice. There were no differences in these variables when comparing adipose tissue from young and 6-month-old mice. While metformin improved glucose homeostasis, it did not increase 5' adenosine monophosphate-activated protein kinase phosphorylation or mitochondrial enzymes. Our findings demonstrate a co-ordinated down regulation of lipolytic, reesterification, and mitochondrial enzymes in adipose tissue with aging that is unresponsive to metformin treatment.

Evaluation of the Influence of thiosemicarbazone-triazole hybrids on genes implicated in lipid oxidation and accumulation as potential anti-obesity agents

A series of thiosemicarbazone-triazole hybrids 1a-h are efficiently synthesised and evaluated for their influence on the expression of genes, cpt-1, acc-1 and pgc-1, which are essential in lipid metabolism. The test results show that hybrids 1c and 1g exhibited relatively high influence on the expression of cpt-1 and pgc-1 and suppression of acc-1 as desired.

Insulin resistance, lipodystrophy and cardiometabolic syndrome in HIV/AIDS

HIV associated insulin resistance, lipodistrophy and cardiometabolic syndrome have been extensively studied and continue to be the scope of much research. There is compelling evidence that both the HIV itself and the therapeutical regimes are major contributors to all of these associated comorbidities. HIV has increasingly been recognized as a disease of accelerated aging, manifested by increased progression of vascular disease and cellular markers of aging. The antiretroviral medication can increase insulin resistance and cause lipotoxocity and HIV-associated lipodystrophy leading to cardiovascular pathology. In this article we review the pathogenesis, management, and prevention of the long-term complications of HIV and its therapies, including cardiovascular disease, lipodystrophy, and insulin resistance along with the growing focus on biomarkers to predict development of end-organ disease. Through a focused literature search we review the established evidence, the developing research about the treatment strategies in treated HIV infection as well as identify potential areas for future research.

Saxagliptin and Metformin in Fixed Combination for the Treatment of Type 2 Diabetes in Adults

Type 2 diabetes affects millions of people worldwide and significantly contributes to morbidity and mortality of those affected by it. Current guidelines recommend individualized treatment regimens following first line metformin therapy. Saxagliptin, a dipeptidyl-peptidase 4 inhibitor, provides a secondary mechanism of action to decrease hyperglycemia when used in combination with metformin. The combination of metformin and saxagliptin has shown improvements in hemoglobin A_1c and fasting plasma glucose in greater efficacy than when either agent is used alone. Adverse effects of combination therapy are similar to when these agents are used individually, and are rated as tolerable by patient satisfaction scores. Overall, the combination use of saxagliptin in addition to metformin is an attractive option for clinicians to use in the treatment of type 2 diabetes.