Protective Effect of Aqueous Garlic Extract Against Renal Ischemia/Reperfusion Injury in Rats

Abstract

Oxygen free radicals are important components involved in pathophysiological tissue alteration observed during ischemia/reperfusion (I/R). This study was designed to determine the possible protective effect of aqueous garlic extract (AGE) on renal I/R injury. Wistar albino rats were unilaterally nephrectomized and subjected to 45 minutes of renal pedicle occlusion followed by 6 hours of reperfusion. AGE (1 mL/kg, i.p., corresponding to 500 mg/kg) or vehicle was administered twice: 15 minutes prior to ischemia and immediately before the reperfusion period. At the end of the reperfusion period, rats were killed by decapitation. Kidney samples were taken for histological examination or determination of levels of free radicals; renal malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Renal tissue collagen content, as a fibrosis marker, was also determined. Creatinine and urea concentrations in blood were measured for the evaluation of renal function. The results revealed that I/R-induced nephrotoxicity, as evidenced by increases in blood urea and creatinine levels, was reversed by AGE treatment. The levels of free radicals, as assessed by the nitro blue tetrazolium test, were increased. Moreover, the decrease in GSH levels and the increases in MDA levels and MPO activity induced by I/R indicated that renal injury involves free radical formation. Treatment of rats with AGE (1 mL/kg) restored the reduced GSH levels, while it decreased free levels of radicals and MDA as well as MPO activity. Collagen contents of the kidney tissues increased by I/R were reversed back to the control levels with AGE. Since AGE administration reversed these oxidant responses and improved renal function and damage at the microscopic level, it seems likely that AGE protects kidney tissue against I/R-induced oxidative damage.

Garlic (Allium sativum L.) and ready-to-eat garlic products: In vitro antioxidant activity

“…Amongst them, garlic (Allium sativum L.) is of particular interest due to its prophylactic and therapeutic actions (Bhagyalakshmi, Thimmaraju, Venkatachalam, Murthy, & Sreedhar, 2005;Kabasakal et al, 2005;Lawson & Gardner, 2005).…”

Garlic Extract Ameliorates Renal and Cardiopulmonary Injury in the Rats with Chronic Renal Failure

“…57 Supporting this speculation, we have previously shown that AGE administration reversed oxidant responses and improved tissue morphology and function in the stomach, ileum, liver, kidney, and bladder, while the reduced GSH levels were restored in all these tissues. 22,58,59 Similarly, renal GSH, SOD, and CAT levels that were decreased in cadmium-intoxicated rats were restored when rats were treated with garlic extract. 60 In many inflammatory disorders, important components of the pathological processes are linked to the ability of neutrophils to release several agents that can destroy normal cells and dissolve connective tissue.…”

“…49 To our knowledge no study has studied the effect of garlic in a renal failure model so far, except for I/R studies. 16,[22][23][24]50 In the current study, the protective effect of AGE against CRF, which is associated with oxidative stress promoting the production of ROS and cytokine release, was studied. The current findings revealed that CRF-induced increases in renal and cardiopulmonary MDA levels, indicating lipid peroxidation and oxidative damage, 51 were ameliorated when the animals were treated with AGE.…”

“…Similarly, it was previously shown in several nephrotoxicity models that oxidative damage in the kidney tissue was prevented Garlic Extract Ameliorates Renal and Cardiopulmonary Injury 723 by AGE, which was demonstrated by reduced MDA levels and restored renal functions. 22,23,26,46,53,54 Oxidative stress-induced tissue damage can be prevented or ameliorated by favoring the balance toward a lower oxidative status. GSH provides major protection in oxidative injury by participating in the cellular defense against oxidative damage and protects protein thiol groups from oxidation, 55 while depletion of tissue GSH is one of the primary factors that permit lipid peroxidation to occur.…”

“…Accordingly, we have previously studied the protective and antioxidant effects of garlic in I/R-induced hepatic, cerebral, and renal injury. [22][23][24] Based on the aforementioned observations, the aim of the present study was to elucidate the possible protective effects of aqueous garlic extract (AGE) on CRF-induced renal, cardiac, and pulmonary injury by using biochemical and histopathological analyses.…”