Effects of Phentermine and Phenformin on Biomarkers of Aging in Rats

Obesity and aging: Molecular mechanisms and therapeutic approaches

The epidemic of obesity is a major challenge for health policymakers due to its far-reaching effects on population health and potentially overwhelming financial burden on healthcare systems. Obesity is associated with an increased risk of developing acute and chronic diseases, including hypertension, stroke, myocardial infarction, cardiovascular disease, diabetes, and cancer. Interestingly, the metabolic dysregulation associated with obesity is similar to that observed in normal aging, and substantial evidence suggests the potential of obesity to accelerate aging. Therefore, understanding the mechanism of fat tissue dysfunction in obesity could provide insights into the processes that contribute to the metabolic dysfunction associated with the aging process. Here, we review the molecular and cellular mechanisms underlying both obesity and aging, and how obesity and aging can predispose individuals to chronic health complications. The potential of lifestyle and pharmacological interventions to counter obesity and obesity-related pathologies, as well as aging, is also addressed.

Decline in biological resilience as key manifestation of aging: Potential mechanisms and role in health and longevity

Decline in biological resilience (ability to recover) is a key manifestation of aging that contributes to increase in vulnerability to death with age eventually limiting longevity even in people without major chronic diseases. Understanding the mechanisms of this decline is essential for developing efficient anti-aging and pro-longevity interventions. In this paper we discuss: a) mechanisms of the decline in resilience with age, and aging components that contribute to this decline, including depletion of body reserves, imperfect repair mechanisms, and slowdown of physiological processes and responses with age; b) anti-aging interventions that may improve resilience or attenuate its decline; c) biomarkers of resilience available in human and experimental studies; and d) genetic factors that could influence resilience. There are open questions about optimal anti-aging interventions that would oppose the decline in resilience along with extending longevity limits. However, the area develops quickly, and prospects are exciting.

Effects of guanylurea, the transformation product of the antidiabetic drug metformin, on the health of brown trout (Salmo trutta f. fario)

Background

Guanylurea is the main transformation product of the antidiabetic drug metformin, which is one of the most prescribed pharmaceuticals worldwide. Due to the high rate of microbial degradation of metformin in sewage treatment plants, guanylurea occurs in higher concentrations in surface waters than its parent compound and could therefore affect aquatic wildlife. In this context, data for fish are scarce up to now which made us investigate the health of brown trout (Salmo trutta f. fario) in response to guanylurea.

Methods

In two experiments, eggs plus developing larvae and juvenile brown trout were exposed to three different concentrations of guanylurea (10, 100 and 1,000 µg/L) and, as a negative control, filtered tap water without this compound. Low internal concentrations were determined. The investigated parameters were mortality, length, weight, condition factor, tissue integrity of the liver and kidney, levels of stress proteins and lipid peroxides, as well as behavioural and developmental endpoints. It was found that guanylurea did not significantly change any of these parameters in the tested concentration range.

Results

In conclusion, these results do not give rise to concern that guanylurea could negatively affect the health or the development of brown trout under field conditions. Nevertheless, more studies focusing on further parameters and other species are highly needed for a more profound environmental risk assessment of guanylurea.

The inhibiting activity of meadowsweet extract on neurocarcinogenesis induced transplacentally in rats by ethylnitrosourea

Inhibitory activity of a decoction of meadowsweet, given postnatally, was studied in rats at risk for neurogenic and renal tumors initiated by transplacental exposure to ethylnitrosourea (ENU). Chemical analysis of ethanol and aqueous extracts of meadowsweet has shown high content of biologically active flavonoids and tannins. Pregnant rats of LIO strain were given a single i.v. injection of ENU, 75 mg/kg, оn the 21st day of gestation. After weaning at 3 weeks after birth, the offspring were divided into two groups: the first was a positive control (ENU), while rats in the second group (ENU + meadowsweet) were given daily a decoction of meadowsweet as drinking water throughout their lifetime. All rats of the first group (ENU) developed multiple malignant tumors, which occurred in brain (86%), spinal cord (43%), peripheral and cranial nerves (29%) and in kidney (31%). More than one-third of CNS tumors were oligodendrogliomas. Mixed gliomas (oligoastrocytomas) occurred less frequently. All other types including astrocytomas, glioblastomas, and ependymomas were rare. All PNS tumors were neurinomas (schwannomas). The spectrum of tumors was similar in rats of the second group. Postnatal consumption of meadowsweet significantly reduced number of tumor-bearing rats (by 1.2 times), the incidence and multiplicity of CNS tumors (brain-by 2.0 and 2.1 times, respectively; spinal cord-by 3.1 and 3.0 times, respectively) and significantly increased latency period, compared to rats of the first group. No significant reduction in PNS or renal tumors was seen in rats given meadowsweet. Meadowsweet extract can be considered an effective cancer preventive agent especially as a neurocarcinogenesis inhibitor.

Methods of testing pharmacological drugs effects on aging and life span in mice

The methodology of testing antiaging drugs in laboratory mice is presented. It is based on more than 40-year-long authors' experience in the field and includes the selection of mouse strain, sex, age at start of treatment, housing conditions, design of the long-term study, some noninvasive methods of assessment of biomarkers of aging, life-span parameters, pathology examination, and statistical treatment of the results.

Antidiabetic Effect of an Active Components Group from Ilex kudingcha and Its Chemical Composition

The leaves of Ilex kudingcha are used as an ethnomedicine in the treatment of symptoms related with diabetes mellitus and obesity throughout the centuries in China. The present study investigated the antidiabetic activities of an active components group (ACG) obtained from Ilex kudingcha in alloxan-induced type 2 diabetic mice. ACG significantly reduced the elevated levels of serum glycaemic and lipids in type 2 diabetic mice. 3-Hydroxy-3-methylglutaryl coenzyme A reductase and glucokinase were upregulated significantly, while fatty acid synthetase, glucose-6-phosphatase catalytic enzyme was downregulated in diabetic mice after treatment of ACG. These findings clearly provided evidences regarding the antidiabetic potentials of ACG from Ilex kudingcha. Using LC-DAD/HR-ESI-TOF-MS, six major components were identified in ACG. They are three dicaffeoylquinic acids that have been reported previously, and three new triterpenoid saponins, which were the first time to be identified in Ilex kudingcha. It is reasonable to assume that antidiabetic activity of Ilex kudingcha against hyperglycemia resulted from these six major components. Also, synergistic effects among their compounds may exist in the antidiabetic activity of Ilex kudingcha.

Metformin supplementation and life span in Fischer-344 rats

Calorie restriction (CR) has been known for more than 70 years to extend life span and delay disease in rodent models. Metformin administration in rodent disease models has been shown to delay cancer incidence and progression, reduce cardiovascular disease and extend life span. To more directly test the potential of metformin supplementation (300 mg/kg/day) as a CR mimetic, life-span studies were performed in Fischer-344 rats and compared with ad libitum feeding and CR (30%). The CR group had significantly reduced food intake and body weight throughout the study. Body weight was significantly reduced in the metformin group compared with control during the middle of the study, despite similar weekly food intake. Although CR significantly extended early life span (25th quantile), metformin supplementation did not significantly increase life span at any quantile (25th, 50th, 75th, or 90th), overall or maximum life span (p > .05) compared with control.

AMP-activated protein kinase and FoxO transcription factors in dietary restriction-induced longevity

Aging is regulated by modifications in single genes and by simple changes in the environment. The signaling pathway connecting insulin to FoxO transcription factors integrates environmental stimuli to regulate lifespan. FoxO transcription factors are directly phosphorylated in response to insulin/growth factor signaling by the protein kinase Akt, thereby causing their sequestration in the cytoplasm. In the absence of insulin/growth factors, FoxO factors translocate to the nucleus where they trigger a range of cellular responses, including resistance to oxidative stress--a phenotype highly coupled with lifespan extension. Our recent results indicate that FoxO transcription factors are also regulated in response to nutrient deprivation by the AMP-activated protein kinase (AMPK) pathway. The energy-sensing AMPK directly phosphorylates FoxO transcription factors at six regulatory sites. AMPK phosphorylation enhances FoxO transcriptional activity, leading to the expression of specific target genes involved in stress resistance and changes in energy metabolism. The AMPK-FoxO pathway plays a crucial role in the ability of a dietary restriction regimen to extend lifespan in Caenorhabditis elegans. Understanding the intricate signaling networks that translate environmental conditions like dietary restriction into changes in gene expression that extend lifespan will be of critical importance to identify ways to delay the onset of aging and age-dependent diseases.

Differential gender effects of a reduced-calorie diet on systemic inflammatory and immune parameters in nonhuman primates

BACKGROUND AND OBJECTIVE

Dietary manipulation, including caloric restriction, has been shown to impact host response capabilities significantly, particularly in association with aging. This investigation compared systemic inflammatory and immune-response molecules in rhesus monkeys (Macaca mulatta).

MATERIAL AND METHODS

Monkeys on continuous long-term calorie-restricted diets and a matched group of animals on a control ad libitum diet, were examined for systemic response profiles including the effects of both gender and aging.

RESULTS

The results demonstrated that haptoglobin and alpha1-antiglycoprotein levels were elevated in the serum of male monkeys. Serum IgG responses to Campylobacter rectus, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were significantly elevated in female monkeys. While only the antibody to Fusobacterium nucleatum was significantly affected by the calorie-restricted diet in female monkeys, antibody levels to Prevotella intermedia, C. rectus and Treponema denticola demonstrated a similar trend.

CONCLUSION

In this investigation, only certain serum antibody levels were influenced by the age of male animals, which was seemingly related to increasing clinical disease in this gender. More generally, analytes were modulated by gender and/or diet in this oral model system of mucosal microbial challenge.

Peripheral blood leukocyte NO production and oxidative stress in multiple sclerosis

BACKGROUND

The reason for increased peripheral blood leukocyte (PBL) nitric oxide (NO) production in patients with multiple sclerosis (MS) is unknown.

OBJECTIVE

To investigate whether PBL NO production is related to measures of oxidative stress.

METHODS

PBL nitrite, diene conjugates (DC, a measure of undergone oxidative stress), antiradical activity (ARA) and antioxidant acitvity (AOA) were measured in 35 healthy control persons and 80 patients with MS. We investigated the correlation of these measures with a partial correlation analysis, with age as the control variable.

RESULTS

There was a significant correlation in both MS patients and healthy control persons between PBL nitrite levels and PBL DC, ARA and AOA. The correlations were stronger in healthy control persons. An analysis by disease subtype showed that the correlations were present in patients with relapsing-remitting and secondary progressive MS, but absent in primary progressive MS.

CONCLUSIONS

PBL nitrite levels and measures of oxidative stress are closely related in MS-patients as well as in healthy control persons. Increased serum NO levels in MS may be the result of a physiologic reaction to overall oxidative stress. The differences in the strength of correlation between different disease subtypes may reflect differences in leukocyte biology.

Dietary thioproline decreases spontaneous food intake and increases survival and neurological function in mice

Male mice on a diet supplemented with thioproline (l-thiazolidine-4-carboxylic acid), a physiological metabolite of 5-hydroxytryptamine, at 2.0 g/kg of food from 28 weeks of age and for their entire life, showed a 23-29% increased median and maximal life span. These survival increases were associated with improved neurological functions. Compared to control mice, thioproline-supplemented mice had a 20% lower integral spontaneous food intake, and 10% lower body weight at 100 weeks of age. Body weight showed a statistically significant inverse relationship with survival and neurological performances. Thioproline-supplemented mice exhibited a 58-70% decrease of the age-dependent oxidative damage in brain and liver mitochondria at 52 weeks (old mice) and 78 weeks (senescent mice) of age, respectively. The age-associated decrease of brain mitochondrial enzyme activities, NADH-dehydrogenase, cytochrome c oxidase, and mitochondrial nitric oxide synthase (mtNOS), in old and senescent mice were markedly prevented (51-74%) by thioproline. In vitro, thioproline neither exhibited direct antioxidant activity nor had any effect on the electron transfer or mtNOS functional activities of brain and liver mitochondria. It is surmised that thioproline induces an anorexic effect associated with improved survival and neurological function through a decreased oxidative damage and regulation that may involve hypothalamic appetite centers.

Caloric restriction mimetics: a novel approach for biogerontology

Caloric restriction remains the only nongenetic intervention that has been consistently and reproducibly shown to extend both average and maximal lifespan in a wide variety of species. If shown to be applicable to human aging, it is unlikely that most people would be able to maintain the 30-40% reduction in food intake apparently required for this intervention. Therefore, an alternative approach is needed. We first proposed the concept of caloric restriction (CR) mimetics in 1998. Since its introduction, this research area has witnessed a significant expansion of interest in academic, government, and private sectors. CR mimetics target alteration of pathways of energy metabolism to potentially mimic the beneficial health-promoting and anti-aging effects of CR without the need to reduce food intake significantly. To date, a number of candidate CR mimetics including glycolytic inhibitors, antioxidants and specific gene-modulators have been investigated and appear to validate the potential of this approach.

Oxidative stress in serum and peripheral blood leukocytes in patients with different disease courses of multiple sclerosis

BACKGROUND

The role of oxidative stress in patients with multiple sclerosis (MS) is poorly understood.

OBJECTIVE

To investigate oxidative stress in serum and peripheral blood leukocytes in patients with different disease courses of MS.

METHODS

Diene conjugate (DC) levels (a measure of lipid peroxidation), total antioxidative activity (AOA) and total antiradical activity (ARA) were measured in serum and peripheral blood leukocytes from 30 patients with benign relapsing remitting MS (BMS), 27 with secondary progressive MS (SPMS), 29 with primary progressive MS (PPMS), and 30 healthy controls. All MS patients were in a clinically stable phase.

RESULTS

Serum DC levels were elevated in patients with BMS (p <0.05), SPMS (p <0.01) and PPMS (p <0.001). Serum total AOA and ARA were not different between MS patients and controls. Compared to controls, leukocyte DC levels were not different in each MS subgroup, but total ARA was elevated. There was a strong correlation, both in controls and MS patients, between leukocyte DC levels and leukocyte total ARA (p <0.0001) and leukocyte total AOA (p <0.0001).

CONCLUSION

Oxidative stress occurs in progressive as well as benign MS. The finding that cells withstand oxidative stress, due to upregulated cellular antioxidant defence mechanisms, suggests that reactive oxygen species (ROS) formation in MS is not necessarily deleterious.