INTRODUCTION

Two types of immunity protect the body: innate and adaptive. Innate immunity is present at birth and provides the first barrier against microorganisms. Adaptive immunity is the second barrier to infection. It is acquired later in life, such as after an immunization or successfully fighting of an infection. The immune system is the body's primary defensive survival mechanism. It can determine what is "self", which needs to be protected and what is "non-self", which needs to be destroyed. A properly functioning immune system allows us to live a life virtually free of illness and disease (Bowers, 1997). Nutrition plays a key role in maintaining optimal immune function. Recent research had shown that maight, if not all, of the body's defenses could be hindered by malnutrition. Cell mediated immunity; antibody production, inflammatory response and secretory and mucosal immunity are some of these functions. Nutritional excesses can also alter the immune response (Wardlaw,1999). Wheat germ is rich in polyunsaturated fats (~12 %),mainly oleic, linoleic, and α- linolenic acids, and vitamins,especially vitamin E,A and B. Its protein content is ~ 28 % and hence wheat germ is a source of essential amino acids with improved nutritional potential if compared to other cereal products. High lipase and lipoxygenase activies also characterize wheat germ. (Sjovall et al., 2000).Whole grain, such as wheat germ are rich sources of dietary fiber, vitamins, minerals and phytochemicals including phenolics, carotenoids, vitamin E, lignans, β-glycan,inulin, resistant starch sterol and phytates (Liu, 2007). 

Plant based foods contain significant amount of bioactive phytochemicals, which when consumed together may have a synergistic affect that goes beyond the basic individual function of each single component in combating diseases (Liu,2007). Wheat germ is therefore sensitive to oxidation that may cause destruction of essential fatty acids and vitamins . Oxidation could be prevented, and shelf life prolonged, by inactivating the enzymes under heat treatment or by removing the oil fraction from wheat germ by extraction, or combined techniques. (Sjovall et al., 2000). There are two types of antioxidants: antioxidant enzymes and nonenzymatic, antioxidant including vitamins E and C, caroteins and phytochemicals. They work by intercepting and stabilizing the reactive oxygen species. Adequate vitamin and mineral intake is nessary for an optimally functioning immune system. Deficiencies and/or excesses of these nutrients can alter the immune response. Understanding the effects of not only nutrient deficiencies but in light of the widespread use of vitamin and mineral supplements excesses as well is crucial(Diplock,1995). Wheat germ is the nutritionally richest part of the seed. It is one of the few plant parts in nature in which the entire vitamin B-complex is found. It also contains fiber and vitamin E (Wood, 1999).In addition, wheat germ oil , rich in vitamin A , has a full balance of mixed tocopherols (α,β- and γtocopherols ) that makes it much more bio-available than other synthetic sources of vitamin E. Furthermore, α-tocopherol is free radical scavengers that give wheat germ oil its potent antioxidant qualities . (Jayaraj et al.,2001).

 Besides,Wheat germ oil is one of the most concentrated natural sources of vitamin E. According to the (USDA.2006), 1,100 mg of non-GMO wheat germ oil (the amount that is in each vegetarian soft gel cap of Wheat Germ Oil E (TM) contains over 164mg of vitamin E in the form of alpha-tocopherol (USDA, 2006). Food irradiation and microwave may play an important role in meeting this challenge. Irradiation technology can be used to process many types of foods, by exposing them to appropriate levels of radiation doses. The United States Department of Agriculture (USDA) and the United States Food and Drug Administration (FDA) in 1983 had approved the use of gamma irradiation on a variety of food products for a number of different purposes like the elimination of microbial contamination. It is the most costeffective technology and is preferred by many processors because the good penetration enables administering treatment to entire industrial pallets or totes, greatly reducing the need for material handling.Food irradiation is recognized as a safe and effective process for a range of specific application, among them the disinfestations of many food items including cereal grains, legumes, fresh and dried fruits, nuts, dried vegetables (W.H.O), 1994). The treatment by gamma rays is regarded as a versatile and effective alternative of chemical fumigants to combat pets combat insect pets. A tirradiated food is wholesome and nutritionally adequate. The FAO/WHO/IAEA Joint Expert Committee on Food Irrediated has unconditionally cleared food irradiated up to 10 kGy as safe for human consumption. Therefore, radiation processing could offer promise to minimize post-harvest losses provided the nutritional quality is not impaired by radiation processing (Diehl, 1995).

 Sample was placed in a pyrex Petri dish (8.0) cm diameter by 1.0 cm deph; each Petri dish contained approx.25g) and heated for the required period. .after that the the wheat germ samples was allowed to cool at room temperature (Yousif ,2004).On the other hand, the forth 5.0 Kg. sample of wheat germ was fermented as described by(Hidvègi et al., 1999) . Methods: (1) Chemical methods: Determination of vitamin contents: Vitamin C was determined according to(Bajaj and Kaur,1981). Besides,vitamins E. and A. were determined according to the methods described by the (Principal Central Lab. of Cairo University, 2008). Experimental animals Sixty three adult male white albino rats, weighing between 135 and 140 grams were obtained from the animal house of the Faculty of Medicine, Assiut University. The animals were kept in wire cages under the normal laboratory conditions. Rats were randomized into (9) groups of (7) animals each. The first group was fed on basal diet (control), the second group was fed on basal diet with 5% of raw wheat germ, the third group was fed on basal diet with 10% of raw wheat germ, the fourth group was fed on basal diet with 5% of microwave treated wheat germ, the fifth group was fed on basal diet with10% of microwave treated wheat germ, the sixth group was fed on basal diet with 5% of gamma irradiated wheat germ, the seventh group was fed on basal diet with 10% of gamma irradiated wheat germ, the eighth group was fed on basal diet with 5% of fermented wheat germ, and the ninth group fed on basal diet with 10% of fermented wheat germ. This modified powdered diet was fed to rats throughout the experimental period of two months to the experiment for acclimatization, and tap water was provided.

 Rats were housed individually in wire cages under the normal laboratory conditions and was fed on the basal diet for a week as adaptation period. The animals were cared for incompliance with the principles and guidance of ethical committee for animal care and use. The basal diet used consisted of corn oil, salt mixture, vitamin mixture and cornstarch as described by (Mohamed 2005). Each rat was marked on the tail to differentiate between animals. Daily administrations were continued for two months. Blood samples: Five ml blood samples were obtained from each rat by eye vein before scarification of rats puncture under complete aseptic conditions. Blood samples were taken into plain tubes, allowed to clot for 2 hours at room temperature before centrifuging for 20 minutes at approximately 1000 x g. Serum samples were stored into aliquots at -20° C till time of assay. (2) Biochemical methods: Determination of interferon gamma (IFN-γ) and interleukin-10 (IL-10 ) in rats Serum levels of rat IFN-γ were determined by Rat IFN-γ Immunoassay Kit. Catalog Number RIF00 by Quantikine,R &Systems Inc, USA. Serum levels of rat IL-10 were determined by Mouse/Rat IL-10 Immunoassay Kit. Catalog Number M2200 by Quantikine,R &Systems Inc, USA. Statistical analysis: Data were tested for normality and were found to be normally distributed. Accordingly, data are presented as the mean±SD. Statistical differences between groups were assessed using paired and unpaired Student t test where appropriate. Repeated measures analysis of variance (ANOVA) was used to compare differences in serial samples. A value of <0.05 was considered statistically significant. Recovery was calculated by dividing the detector response of analyze in the sample to the response of analyze reference material.

 Correlation analysis between the different studied variables was performed using spearman’s rank correlation coefficient. All analyses were performed using Statistical Package for Social Sciences (SPSS) software (version 11.0). RESULTS AND DISCUSSION Vitamins contents: The data given in Table (1) revealed that fermented wheat germ recorded the highest percentages in Vitamin (A) and Vitamin (C) (16555.70 IU/100g) and (125.82 mg/100g); respectively. However microwave treated wheat germ had the highest content of vitamin (E) (1840 IU/100g ).While gamma irradiated wheat germ recorded the lowest percentages of Vitamin (A) and Vitamin (C) (7941.80 IU/100g and 87.78 mg/100g) ; respectively. On the other hand, raw wheat germ recorded the lowest percentages of Vitamin (E) (1312 IU/100g). Serum levels of interferon gamma (INF-γ) in Albino rats fed on wheat germ with different treatments and basal diet: Serum levels of IFN-γ in Albino rats fed on wheat germ with different treatments and control are presented in table (2). The data revealed that there was significant increase in serum levels of INF-γ in groups V(basal diet with 10% of microwave wheat germ) (P < 0.01), VI ( basal diet with 5% of gamma irradiated wheat germ), VII (basal diet with 10% of gamma irradiated wheat germ), VIII (basal diet with 5% of fermented wheat germ), IX(basal diet with 10% of fermented wheat germ) (P<0.001) for each in comparison to group I basal diet (control).Although level of INF-γ in group II, ( basal diet with 5% of raw wheat germ ),III ( basal diet plus 10% of raw wheat germ),IV(basal diet with 5% of microwave wheat germ) were higher than that the fact that of group I but the difference did not reach the level of significance.

 This might be due to wheat germ is rich sources of dietary fiber, vitamins, minerals and phytochemicals including phenolics, carotenoids, vitamin E, lignans, β-glycan,inulin, resistant starch sterol and phytates (Liu, 2007). Among the causes the deficiency are an inadequate diet, impaired digestion and /or absorption, altered metabolism, a disease state, increased utilization of a nutrient and increased need for a nutrient. Excesses of specific nutrient can also alter immune function. Certain nutrients, including vitamins C and E, affect various parts of immune function when present in excess quantities (Bowers, 2002).The effects of malnutrition on immunity had been extensively studied and were well documented (Scrimshaw,1997). In case of protein energy malnutrition there is increased morbidity and mortality from infections due to suboptimal immune systems. The increased rate of infection and death in protein energy malnutrition is due to the inability of the immune system to resist and/or effectively fight the infection. Without adequate vitamin E the immune system does not function normally. Phagocytosis as well as cell mediated and humoral immunity are all impaired. Vitamin E supplementation appears to enhance immunity and resistance to infections in animals and quite possibly humans (Meydani,1996).Vitamin E has immune functions beyond its role as an antioxidant, such as regulation the synthesis of eicosanoids on immune cell membranes, keeping the cells from overproducing eicosanoids. When vitamin E is deficient, production of the immunosuppressive PGE, is increased, which impairs immune function (Bendich, 1990).

Vitamin E supplementation increase differential count (lymphocytes and monocytes).( Abdel Ghafar,2004).On the other hand, vitamin E deficiency induces the decrease differentiation of immature T cells which results in the early decrease of cellular immunity(Moriguch and Muraga, 2000). Vitamin E enhances some measures of immune-cell activity in the elderly (Meydani et al.,1990). This effect was more pronounced with 200 IU per day, while under 200 IU per day had not boosted immune function in some reports ( De Waart et al., 1997).Beta-carotene and other carotenoids had increased immune cell numbers and activity in animal and human research. An effect that appears to be separate from their role as precursors to Vitamin A. (Chew,1993). Placebo-controlled research had shown positive benefits of beta-carotene supplements in increasing numbers of ,some white blood cells and enhance in cancer- ling Immune functions in healthy people at 25,000-100,000 IU per day(Hughes et al., 1997).In double-blind trials in the elderly, supplementation with 40.000--150,000 IU per day of betacarotene has increased natural killer (NK) cell activity (Santos et al,1996), but not several other measures of immunity(Santos et al,1997). Vitamin C stimulates the immune system by both elevating interferon levels (Gerber,et al.,1975 )and enhancing the activity of certain immune cells (Anderson,1984). Vitamin C improves immune function in the elderly (Delafuente et al.,1986) Vitamin A plays an important role in immune system function and helps mucous membranes, including those in the lungs, resist invasion by microorganisms (Semba,1994). 

However, most research showed had while vitamin A supplementation helped people to prevent or treat infections in developing countries where deficiencies are common (Glasziou and Mackerras,1993). Plant lectins, such as wheat germ agglutinin constitute common components of the human diet and target the immune system on a daily basis. The wheat germ-deprived diet induced a state of functional unresponsiveness in lymphocytes from primary and secondary lymphoid organs, as evaluated by in vitro stimulation with T cell mitogen phytohaemoagglutinin and B cell mitogen lypoplysaccharides. The unresponsive state on the immune cells colud be revesed by injection of antigen emulsified in oil with inactivated mycobacteria . Dietary signals can thus interact with the immune system possibly influencing its shaping during ontogenesis.( Chignola et al., 2002 )