The Possible Ultra Structural Ameliorative Effect of Taurine in Rat’s Liver Treated with Monosodium Glutamate (MSG)

ABSTRACT

Monosodium glutamate (MSG) is a food additive with a wide range of biological effects but its high dose and long period of using can cause a toxic effect on liver. Taurine is a derivative that produces antioxidant in many tissues including liver. The current research concerned with biochemical, histopathological and ultra structural changes in rats liver treated with MSG and throw light on the possible ameliorative effect of taurine – 150 male albino rats were divided into five group each containing 30 rats (controls, taurine, MSG, therapeutic and protective group). Serum AST, ALT, ALP and bilirubin (direct and total) were measured, as well as histopathological and ultrastructural changes in liver tissues were examined in all groups. The rats received MSG orally in a dose 400 mg/Kg. B. wt for 8 weeks (MSG group), while taurine induced orally in a daily dose at 1000 mg/Kg. B. wt alone (Taurine group) or after MSG (therapeutic) or before MSG (protective) for the same period, in addition to frank control group received orally 2 ml saline per day during the experiment. The results showed marked and gradual increase in the serum levels of AST, ALT, ALP and bilirubin (direct and total) in MSG group as compared to control group. The histopathological structure of the same group showed hepatic and local hemorrage as well as necrosis of hepatocytes with pyknotic nuclei after 4 weeks of the treatment, while after 8 weeks portal edema, thickening in wall of bile duct and portal infiltration were observed. Ultra structure examination in the same group after 8 weeks showed hyaline degeneration; rough endoplasmic reticulum with irregular nuclear membrane and cytoplasm rich in glycogen granules, Interestingly, the results showed a significant restore of hepatic injury as evidenced by attenuation of hepatocellular enzyme and bilirubin release and reduction of hepatocyte necrosis and then portal infiltration in therapeutic group reduction of hepatocyte necrosis and then portal infiltration therapeutic group. While complete normalization in plasma ALT, AST, ALK and bilirubin levels with complete restore of histological and ultra structural arrangement of hepatocyte were observed in protective group.

In conclusion, the results confirm the hepatotoxic effect of MSG and improve the hepatoprotective effect of taurine, especially when it administrated as a protective substance than therapeutic. Also, we advice to add a suitable dose of taurine to any food containing MSG as a food additive.