Efeitos da acupuntura, eletroacupuntura e metformina sobre o estresse oxidativo, inflamação e glicemia em ratas sadias submetidas a estímulo estrogênico

Abstract

The physiological performance of cellular activity requires a balance between the production of free radicals and their deactivation by regulators and surge protectors. When this balance is broken, the oxidative stress takes place. Several experimental studies using estrogens to induction of ovarian and metabolic disorders, with emphasis on the polycystic ovary syndrome (PCOS), are available in the scientific literature.The Metformin (MTF) is a medication used for diabetic patients, and is often used for treatment of Polycystic Ovary Syndrome (PCOS), allowing restoration of cyclicality, induction of ovulation and menstruation. Acupuncture (Ac) and Electroacupuncture (EAc) are used in Traditional Chinese Medicine for the promotion of organic equilibrium, through stimulation of nerve pathways producing specific neurotransmitters, resulting in an antinflammatory, analgesic and autonomic regulatory response.This study aimed at evaluating the effects of MTF and Ac and EAc, applied on Zusanli (E36) and Sanyjiao (BP6) acupoints on the local and systemic oxidative stress, inflammation and blood glucose levels in healthy rats submitted to estrogenic stimulation. In the experiment, 42 rats were distributed randomly assigned into seven groups. In the experiment, 42 rats were randomly assigned into seven groups. Thirty rats (groups G1C , G2M, G3Ac, G4EAc2, G5EAc100) were administered estrogen (estradiol valerate, 4mg, single dose). The two remaining groups served as negative controls (G6M, G7) and received no estrogenic stimulation. After 60 days, began the second phase of the study, comprising a ten-day period. Ac and EAc (2/100Hz), were applied for 20 minutes, under anesthesia, in alternated days during nine days, to groups G3Ac, G4EAc2, and G5EAc100. MTF was given daily during nine days by gavage to G2M and G6M groups. On the 10th day, all rats were subjected to the oral glucose tolerance test, and evaluated on three occasions: before the beginning of the test and after 60/120 minutes. Next, followed laparotomy, under anesthesia, for collection of blood from the abdominal aorta artery and harvesting of uterus and ovary for examination. Parameters analysed included the Thiobarbituric Acid Reactive Substances (TBARS), reduced Glutathione (GSH), Myeloperoxidase (MPO), and ovarian histopathology. At the end of the experiment plasma concentrations of GSH increased significantly in G3Ac, G4EAc2 and G5EAc100 groups compared to G1 (24.50±1.59 vs 20.30±0.43, p<0.05; 30.80±3.22 and 40.30±3.48 vs 20.30±0.43, p<0.0001) respectively. There has been a significant increase in concentrations of GSH in ovarian tissue of rats treated with EAc2/100 (47.00±17.60 vs 25.70±2.33, p<.005 and 63.00±12,40 vs 25,70±2.33, p<0.0001). There was a significant reduction in ovarian MPO activity in groups G4EAc2 and G5EAc100 (0.59±0.21 vs 1.76±0.31, p<0.05 and 0.65±0.05 vs 1.76±0.31p<0.001). MTF did not promote changes in oxidative or inflammatory markers. There was no change in blood glucose levels in any of the groups studied. Corpus luteum and follicular cysts number were not different in all groups. It is concluded that EAc2/100Hz treatments promote systemic and local protection on oxidative stress by increasing GSH concentrations and by reducing the inflammatory status in the ovary of healthy rats submitted to estrogenic stimulation.