Journal of American Science 2012;8(1s) http://www.jofamericanscience.org 146 Effect of Honey on Monosodium Glutamate Induced Nephrotoxicity (Histological and Electron Microscopic Studies) Amal A. Afeefy 1 , Marwa S. Mahmoud 2 and Mona A.A. Arafa 1 Anatomy Department, Faculty of Medicine, Alazhar university 1, Zoology Department, Faculty of Science, Beni-Suef University 2 Amal.afeefy73@yahoo.com Abstract: Monosodium glutamate (MSG) is frequently used as a flavor enhancer, the fact of which makes it one of the most applied food additives in the modern nutrition all over the world. The aim of this work was to study the effect of bees honey on MSG-induced kidney damage. Sixty adult male albino rats were divided into three groups. Group I animals served as control were given saline for 30 days. Group II animals were given MSG in saline for 30 days. Animals of group III were treated with 6mg/g b.wt MSG and 2mg / rat / day of bees honey for 30 days. Light and transmission electron microscopic examination was used for study the histological changes. Light microscopic examination of the cortex in kidney after administration of MSG, revealed severe dilatation of Bowman's capsule and shrinkage of glomeruli. Loss of brush border of proximal convoluted tubules and dilatation of both proximal and distal convoluted tubules were noticed, in addition to areas of huge vacuole were also observed. The medulla of MSG treated rats showed sever histological changes in collecting tubules and collecting duct showed thin rim of cytoplasm and small deeply stained nuclei. Most of loops of Henle are undifferentiated with the presence of several areas of syncytium. Moreover PAS positive reaction was decreased. Results obtained by electron microscopic examination revealed that there was partial loss of brush border of proximal convoluted tubules with destruction of most cytoplasmic organelles and thickening of basement membrane. In addition, the lumen of several tubules was filled with cell debris. The nuclei of podocytes and endothelial cells frequently appeared irregular with nuclear condensation, moreover thickening of basal lamina were observed also. It is noticed that concurrent administration of bees honey with MSG improved histological changes in kidney by light and electron microscope. It could be concluded that honey via its antioxidant activity has the ability to protect against MSG induced histopathological, and ultrastructural alterations to near normal. [Amal A. Afeefy Marwa S.Mahmoud and Mona A.A. Arafa. Effect of Honey on Monosodium Glutamate Induced Nephrotoxicity (Histological and Electron Microscopic Studies). J Am Sci 2012;8(1s):146-156]. (ISSN: 1545-1003). http://www.americanscience.org . 23 Keywords: kidney, histopathology, ultrastructure, monosodium glutamate, honey. 1. Introduction Various environmental chemicals, industrial pollutants and food additives have been implicated as causing harmful effects, (Kirk-Othmer, 1992). Monosodium glutamate (MSG) is a common example of one of the chemicals used in our modern Foods. It is the sodium salt of glutamic acids. Glutamate is one of the most common amino acids in nature and is the main component of many proteins and peptides of most tissues. Monosodium glutamate contains 78% glutamic acid, 22% sodium and water (Adrienne, 1999). During intestinal absorption, a large amount of glutamic acid is transaminated and consequently alanine levels in portal blood are elevated. If large amounts of glutamate are ingested, portal glutamate levels will increase, this elevation results in an increase hepatic metabolism of glutamate, leading to release of glucose, lactate, glutamine, and other amino acids into systemic circulation (Stegink, 1984). Glutamic acid is transformed into alanine in intestinal mucosa and lactate in liver (Garattiini, 2000). Glutamic acid is absorbed from gut by active transport system specific for amino acids. The injection of MSG (4 mg/g b.wt.) to the rats in food resulted in a decrease of the number of Grafian follicles and lowered the thickness of endometrial. MSG induced alterations in metabolic rate of glucose utilization and decreased antioxidant defenses (Miskowiak et al., 1999). MSG caused many pathological effects; it alters the activity and sensitivity of rat hypothalamo- pituitary- adrenocortical axis (Larson et al., 1999). It produces neurotoxicity (Park et al., 2000) and (Singh et al., 2003), obesity and impaired vision (Praputpittaya and Wililak, 2003). Chronic administration of MSG (4mg/g b. wt. and above) induced oxidative stress in experimental animals (Ahluwalia et al., 1996, Singh et al., 2003 and Diniz et al., 2004). The human body possesses a number of mechanisms to deal with the potentially damaging effects of free radicals and their metabolic products. Nutrients also contribute to defense against oxidative stress and cellular damage. Honey is a product produced by bees from the nectar and other sugary substances derived from many