Thousands of food additives are widely used in food processing and people consume daily a considerable amount of these additives. Monosodium glutamate (MSG) is the sodium salt of glutamic acid, an abundant naturally occurring amino acid (Walker et al., 2000). It can produce a unique taste, known as a fifth taste (umami) that cannot be provided by other basic taste. MSG has also the ability to enhance diet intake in older (Bellisle, 1998; Yamaguchi, 1998; Yamaguchi and Ninomiya, 2000). This popular taste enhancer is extensively used not only in the food industry, but also in restaurants and homes. It is present in a wide variety of processed foods including flavored chips and snacks, soups or sauces (canned, packed), prepared meals, frozen foods, marinated meats, fresh sausages, bottled soy or oriental sauces, and stuffed or seasoned chicken, manufactured meats, some hams, luncheon chicken and turkey, flavored tuna, vegetarian burgers and sausages (Bojanić et al., 2009). Moreover, glutamate is present naturally in various foods comprising cheese, sea foods, meat broths, poultry, vegetables and other food. It represents an essential constituent in the taste of these foods (Halpern et al., 2000). Glutamate plays a vital role in the body.It acts as an energy source for some tissues and as a substrate for glutathione synthesis (Jinap and Hajeb, 2010).
Monodosium glutamate (MSG) was categorized as a safe substance by the Food and Drug Administration (FDA) in 1959. However, in 1995, FDA Commissioned report acknowledged that an unknown percentage of the population may react to monosodium glutamate and develop monosodium glutamate symptom complex (U. S. Food and Drug Administration, 1995). Thus application of MSG in foods may contribute to health hazards. In confirm, studies on experimental animals showed that long term consumption of this flavoring agent produced toxic effects on human health, referred to as Chinese restaurant syndrome (Pavlovic and Sarac, 2010).
A plethora of evidence suggested that glutamate-induced toxicity could be mediated via necrosis and apoptosis (Ankarcrona et al., 1995; Martin et al., 2000a). Furthermore, it has been shown that MSG increased rat thymocytes apoptosis, by down-regulation of antiapototic (Bcl-2) gene expression in thymocytes (Pavlovic et al., 2006). Several studies demonstrated that MSG induced oxidative stress and toxicity in different organs including the pancreas (Nwaopara et al., 2004), liver (Nwaopara et al., 2007), kidney (Nwaopara et al., 2008) and thymus (Farombi and Onyema, 2006; Pavlovic et al., 2007; Singh et al., 2003;).
The major role of thymus gland in the body is a process known as Education. This process means the ability of naive cell to distinguish self from nonself and to differentiate a healthy cell from an abnormal cell. Beneficial T cells to the immune system are spared while harmful ones are eliminated. The mature T cells are then released into the bloodstream.Errors (Pawlowski and...