Snake venoms are complex mixtures, composed of many hundred different peptides, enzymes, toxins and inorganic ions with a wide spectrum of biological activities. The present study was aimed to evaluate anti-bacterial effect of the crude venom of the Egyptian cobra (Naja haje) at dose of mice median lethal dose (LD50) on some strains of bacteria and the bio-physiological effect of subcutaneously injecting two sub-lethal doses (1 /2 LD50 & 1 /10 LD50) venom on Swiss albino mice. The E. coli was found to be high resistance to the venom in both the minimum inhibitory concentration (MIC) and disc diffusion, while the venom affected on S. typhi and S. aureus, it showing zones of inhibition in disc diffusion and MIC. The sera biochemical parameters of injected animals with the Egyptian cobra venom with two different doses showed high significant increase in liver and cardiac enzymes in addition to kidney function tests (urea and creatinine) compared to control group. The mice complete blood pictures (CBC) showed in both of the two doses a significant decrease in hemoglobin (Hb) concentration and platelets count, while red blood cells (RBCs) and white blood cells (WBCs) count revealed highly significant decrease. Histological examination showed alterations in liver, kidney and heart tissues of mice injected with two doses of venom. Also, the skin tissue showed dermal oedema with few inflammatory cells.
