Intensity of Free Radical Processes in Rat Liver under Type 2 Diabetes and Introduction of Epifamin

Influence of 10-(6-plastoquinonyl) decyltriphenylphosphonium on free-radical homeostasis in the heart and blood serum of rats with streptozotocin-induced hyperglycemia

BACKGROUND

It is known that under conditions of tissue tolerance to insulin, observed during type 2 diabetes mellitus (DM2), there is an increased production of reactive oxygen species. Moreover, the free radicals can initiate lipid peroxidation (LPO) in lipoprotein particles. The concentration of LPO products can influence the state of insulin receptors, repressing their hormone connection activity, which is expressed as a reduction of the glucose consumption by cells. It is possible that reduction in glucose concentration during administration of 10-(6-plastoquinonyl) decyltriphenylphosphonium (SkQ1) to rats with DM2 may be related to the antioxidant properties of this substance.

AIM

To establish the influence of SkQ1 on free-radical homeostasis in the heart and blood serum of rats with streptozotocin-induced hyperglycemia.

METHODS

To induce hyperglycemia, rats were fed a high-fat diet for 1 mo and then administered two intra-abdominal injections of streptozotocin with a 7-d interval at a 30 mg/kg of animal weight dose with citrate buffer equal to pH 4.4. SkQ1 solution was administered intraperitoneally at a 1250 nmol/kg dose per day. Tissue samples were taken from control animals, animals with experimental hyperglycemia, rats with streptozotocin-induced glycemia that were administered SkQ1 solution, animals housed under standard vivarium conditions that were administered SkQ1, rats that were administered intraperitoneally citrate buffer equal to pH 4.4 once a week during 2 wk after 1-mo high-fat diet, and animals that were administered intraperitoneally with appropriate amount of solution without SkQ1 (98% ethanol diluted eight times with normal saline solution). To determine the intensity of free radical oxidation and total antioxidant activity, we used the biochemiluminescence method. Aconitate hydratase (AH), superoxide dismutase, and catalase activities were estimated using the Hitachi U-1900 spectrophotometer supplied with software. The amount of citrate was determined by means of the Natelson method. Real-time polymerase chain reaction was carried out using an amplifier ANK-32.

RESULTS

It was found that the mitochondrial-directed antioxidant elicits decrease of biochemiluminescence parameter values that increase by pathology as well as the levels of primary products of LPO, such as diene conjugates and carbonyl compounds, which indicate intensity of free radical oxidation. At the same time, the activity of AH, considered a crucial target of free radicals, which decreased during experimental hyperglycemia, increased. Apparently, increasing activity of AH influenced the speed of citrate utilization, whose concentration decreased after administering SkQ1 by pathology. Moreover, the previously applied anti-oxidant during hyperglycemia influenced the rate of antioxidant system mobilization. Thus, superoxide dismutase and catalase activity, as well as the level of gene transcript under influence of SkQ1 at pathology, were changing to the direction of control groups values.

CONCLUSION

According to the results of performed research, SkQ1 can be considered a promising addition to be included in antioxidant therapy of DM2.

Effects of N-[Imino(1-Piperidinyl)Methyl] Guanidine on the Intensity of Free Radical Processes, Aconitase Activity, and Citrate Level in the Tissues of Rats with Experimental Type 2 Diabetes Mellitus

Effects of a synthetic biguanide derivative N-[imino(1-piperidinyl)methyl] guanidine (NIPMG) on free radical homeostasis, aconitase activity, and citrate concentration were studied in the liver and blood serum of rats with type 2 diabetes mellitus. Analysis of biochemiluminescence parameters showed that administration of this agent (10 mg/kg body weight) to animals with diabetes reduced the intensity of free radical processes in study tissues relative to the increased values in untreated diabetic animals. Under these conditions, aconitase activity, a principal target of ROS effects, and citrate level in the liver and blood serum of rats approached the control levels. The results show that NIPMG can positively regulate free radical homeostasis and reduce the intensity of oxidative stress in type 2 diabetes mellitus, which was accompanied by normalization of the studied parameters.

Intensity of apoptotic processes, aconitate hydratase activity and citrate level in patients with type 2 diabetes mellitus complicated steatohepatitis under application of epifamin at basic therapy

DNA fragmentation, caspase-1 and caspase-3, aconitate hydratase (AH) activities, and citrate content have been investigated in the blood of patients with type 2 diabetes mellitus complicated by steatohepatitis. These indicators of apoptotic processes intensity and oxidative stress development were estimated after basic treatment and a combined therapy including epifamin. Before treatment DNA fragmentation blood leukocytes, decrease of AH activity and increase of caspases activities in the serum of patients were detected. Treatment with epifamin provided more pronounced changes in the investigated parameters towards control values as compared to basis therapy. Epifamin caused a positive effect on the citrate content in the serum of patients. Epifamin inclusion to the basic therapy was accompanied by a more pronounced changes towards the normal values of such biochemical parameters as ALT, AST, b-lipoproteins, cholesterol, fasting glucose and postprandial glucose levels. All these changes may be obviously attributed to epifamin-induced correction of the melatonin level and manifestation of adaptogenic properties and antioxidant effects of the hormone.