Efeitos modulatórios do óleo de alho (allium sativum), da acupuntura e da eletroacupuntura no estresse oxidativo agudo e na inflamação induzidos por gentamicina no fígado do rato

Abstract

Aminoglycosides, introduced to the therapeutic arsenal for almost 70 years, continue to be the drug of choice in patients with serious infections, produced by gram-negative bacilli. The toxic effects of gentamicin (GM), are known for a long time. Available studies in the scientific literature, published in 2010 and 2011, have demonstrated that the administration of 200 mg of gentamicin in a single dose by gavage, produced toxic and oxidative effects in heart, kidney and liver of Sprague-Dawley rats Nevertheless, they are still relatively few studies investigating the hepatotoxic effects of this drug. Garlic (Allium sativum), used in folk medicine since antiquity, has many biological activities, such as anticancer, antimicrobial, antihypertensive, immunomodulatory and antioxidant activities.In the presence of oxidative stress the garlic oil (GO) modulates levels of antioxidants and lipid peroxidation, acting on elimination of free radicals. It is known, moreover, that the application of acupuncture (Ac) in acupoint VB34 (Yanglingquan) reduces the toxicity, protects liver tissue and normalizes the immune activity in rats intoxicated by carbon tetrachloride (CCl4). The use of electroacupuncture (EAc) can potentiate the effects of Ac. For assessment of antioxidant and anti-inflammatory activity of OA, Ac and EAc ,a prospective, controlled and compared study was carried out in Wistar rats submitted to the hepatotoxic effects of GM. Thirty male rats, aged from 12 to 14 weeks and weight ranging from 267 to 373 g. were randomly distributed into five groups of six animals: G1(control), G2- garlic oil, G3 Ac, G4 EAc2 (electroacupuncture 2 Hz), G5-EAc100 (electroacupuncture100 Hz). For the induction of hepatotoxicity all animals received GM (ip 100mgKg) during 5 consecutive days. Beginning on the 7th day the rats (G2) were treated with garlic oil (by gavage), Ac and EAC (2-100 Hz) (G3-G5) for 20 minutes on alternate days for 10 days. G1 rats received olive oil by gavage. Arterial blood samples and the liver were collected 48 hours after the end of the experiment, under anesthesia with chloral hydrate. Parameters analyzed included, aspartate amino transferase (AST) - alanine amino transferase-(ALT), malondialdehyde (MDA), reduced Glutathione (GSH) and myeloperoxidase (MPO). Next the rats were killed by triple dose of anesthetic. G1 AST and ALT values were similar to normal values known, suggesting that the toxic lesions were of lower intensity possibly due to a short period of induced toxicity. There was a significant increase of plasma and tissue concentrations of GSH in groups G4 and G5, compared to positive control. No differences were observed in plasma MDA concentrations. However there was a significant increase in the of hepatic MDA concentration, comparing the Group G5 to positive control G1. There was significant reduction of MPO activity in the liver of G4 and G5 rats. These findings confirm the antiinflammatory activity of the EAc. It is concluded that the EAc has a protective effect on hepatic oxidative stress and liver inflammation of GM intoxicated rats. Garlic oil showed no protective effect at the doses used in this study. Keywords: Gentamicin; Oxidative stress; Inflammation; Acupuncture; Eletroacupuncture.