Chromium levels in insulin-sensitive tissues and the thigh bone are modulated by prednisolone and high-fat diets in mice

Exercise Affects Blood Glucose Levels and Tissue Chromium Distribution in High-Fat Diet-Fed C57BL6 Mice

Obesity is commonly associated with hyperglycemia and type 2 diabetes and negatively affects chromium accumulation in tissues. Exercise prevents and controls obesity and type 2 diabetes. However, little information is available regarding chromium changes for regulating glucose homeostasis in high-fat diet (HFD)-fed animals/humans who exercise. Therefore, this study explored the effects of exercise and whether it alters chromium distribution in obese mice. Male C57BL6/J mice aged 4 weeks were randomly divided into two groups and fed either an HFD or standard diet (SD). Each group was subgrouped into two additional groups in which one subgroup was exposed to treadmill exercise for 12 weeks and the other comprised control mice. HFD-fed mice that exercised exhibited significant lower body weight gain, food/energy intake, daily food efficiency, and serum leptin and insulin levels than did HFD-fed control mice. Moreover, exercise reduced fasting glucose and enhanced insulin sensitivity and pancreatic β-cell function, as determined by homeostasis model assessment (HOMA)-insulin resistance and HOMA-β indices, respectively. Exercise also resulted in markedly higher chromium levels within the muscle, liver, fat tissues, and kidney but lower chromium levels in the bone and bloodstream in obese mice than in control mice. However, these changes were not noteworthy in SD-fed mice that exercised. Thus, exercise prevents and controls HFD-induced obesity and may modulate chromium distribution in insulin target tissues.

Effect of Chromium Supplementation on Element Distribution in a Mouse Model of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder and one of the most common causes of anovulatory infertility. In addition, insulin resistance is commonly associated with PCOS and contributed to pathophysiology connected to dietary minerals including chromium (Cr), copper (Cu), iron (Fe), and zinc (Zn). The aims of this study were to explore whether PCOS in mice alters levels of these elements and determine if Cr supplementation resolves changes. Twenty-four female BALB/c mice were divided into three groups of eight mice [normal control (NC), PCOS+placebo milk (PP), and PCOS+Cr-containing milk (PCr)]. Each group received a high-fat diet for 4 weeks. Our results show significantly higher levels of dehydroepiandrosterone (DHEA) (p<0.001), fasting glucose (p<0.05), and fasting insulin (p<0.05) in the PP group compared with both NC and PCr group. However, Cr levels were significantly lower in muscle, bone, and serum in the PP group (p<0.05) compared with NC and PCr groups. In liver, bone, and serum, Fe levels were significantly higher in the PP group compared with the NC group (p<0.05). In addition, we found significant correlations between Cu/Zn ratio and fasting insulin in all mice (r=0.61; p=0.002). Given that significant research shows that Cr supplementation improves fasting glucose, fasting insulin, and metal metabolism disorders for PCOS mice, our data suggest that trace element levels can serve as biomarkers to prescribe therapeutic supplementation to maintain a healthy metabolic balance and treat disease conditions.

Effects of chromium malate on glycometabolism, glycometabolism-related enzyme levels and lipid metabolism in type 2 diabetic rats: A dose-response and curative effects study

Aims/Introduction

The present study was designed to evaluate the effect of chromium malate on glycometabolism, glycometabolism-related enzyme levels and lipid metabolism in type 2 diabetic rats, and dose–response and curative effects.

Materials and Methods

The model of type 2 diabetes rats was developed, and daily treatment with chromium malate was given for 4 weeks. A rat enzyme-linked immunosorbent assay kit was used to assay glycometabolism, glycometabolism-related enzyme levels and lipid metabolism changes.

Results

The results showed that the antihyperglycemic activity increased with administration of chromium malate in a dose–dependent manner. The serum insulin level, insulin resistance index and C-peptide level of the chromium malate groups at a dose of 17.5, 20.0 and 20.8 μg chromium/kg bodyweight were significantly lower than that of the model, chromium trichloride and chromium picolinate groups. The hepatic glycogen, glucose-6-phosphate dehydrogenase and glucokinase levels of the chromium malate groups at a dose of 17.5, 20.0 and 20.8 μg chromium/kg bodyweight were significantly higher than that of the model, chromium trichloride and chromium picolinate groups. Chromium malate at a dose of 20.0 and 20.8 μg chromium/kg bodyweight significantly changed the total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides levels compared with the chromium trichloride and chromium picolinate groups.

Conclusions

The results showed that chromium malate exhibits greater benefits in treating type 2 diabetes, and the curative effect of chromium malate is superior to chromium trichloride and chromium picolinate.

The effects of antihypertensive drugs on chromium status, glucose metabolism, and antioxidant and inflammatory indices in spontaneously hypertensive rats

The long-term use of hypotensive drugs may cause side effects, including impaired glucose metabolism and mineral status. This study tested the hypothesis that some hypotensive drugs can affect tissular chromium levels and indices of glucose metabolic and antioxidant potential in rats. The experiment was performed on 40 male spontaneously hypertensive rats (SHRs), which were assigned to five groups: control (C), with perindopril (PR), with metoprolol (MT), with indapamide (ID), and with amlodipine (AM). All rats were provided ad libitum standard diet (with or without drugs) and distilled water for 45 days. Glucose and insulin levels, along with total antioxidant status (TAS) and concentrations of TNF-alpha and C-reactive protein, were assayed in serum. Chromium concentrations in the liver and kidney were determined using the flame atomic absorption spectrometry method. Detailed statistical analysis was performed using Statistica for Windows 10.0 (StatSoft, Poland). One-way analysis of variance (ANOVA), followed by a post hoc Tukey test, was used to compare the data between groups. Treatment with indapamide and amlodipine resulted in significantly higher chromium concentrations in the liver and kidney (AM) of the rats, compared with the control group. A markedly higher concentration of glucose was found in the ID group. Treatment with amlodipine significantly increased TAS levels in serum and decreased TNF-alpha concentration in serum of the rats. A significant positive correlation between chromium concentration in tissues and serum TAS level was observed, as was a significant negative correlation between chromium concentration in the kidneys, and TNF-alpha and glucose levels in serum. In conclusion, the administration of amlodipine may lead to an increase in chromium accumulation in the internal organs, which is associated with increased antioxidant status and suppression of the inflammatory response of cells in SHRs.