Effects of Apocynin against Monosodium Glutamate-Induced Oxidative Damage in Rat Kidney
Merve Açıkel Elmas, Gökçen Özgün, Özlem Bingöl Özakpinar, Zozan Güleken, Serap ArbakObjective: Monosodium glutamate causes oxidative stress that affects a variety of organ systems, along with the kidney. The aim of this study was to evaluate the protective role of apocynin in kidney degeneration caused by monosodium glutamate using biochemical and histological methods. Materials and Methods: Sprague-Dawley rats (n=32) were used for this study. Four experimental groups were randomly formed: the Control (Cont), Apocynin (APO), Monosodium Glutamate (MSG), and MSG+APO groups. The MSG group received oral administration of MSG (120 mg/kg) for 28 days. The MSG+APO and APO groups received apocynin (25 mg/kg) during the last 5 days of the experiment. Kidney tissue was processed for biochemical and microscopic analyses. Biochemical methods were used to examine the levels of malondialdehyde (MDA) and glutathione (GSH) in the tissue and the activities of myeloperoxidase (MPO) and superoxide dismutase (SOD). Light and electron microscopy were also used to examine for histological changes in kidney tissue. Results: The MSG group was compared with the Cont and APO groups; it was found that MDA and MPO levels were elevated, whereas GSH and SOD activity were decreased. In contrast to the Cont and APO groups, the MSG+APO group showed higher GSH levels, lower MPO activities and increased MDA levels. While apocynin treatment improved renal tissue histology, MSGinduction led to deterioration of renal morphology. Conclusion: The study revealed that MSG increased oxidative damage and renal tissue degeneration. Moreover, apocynin reduced renal damage by modulating the ratio of antioxidants to oxidants.