In vivo effects of sodium benzoate on plasma aspartate amino transferase and alkaline phosphatase of wistar albino rats

The in vivo effects of varying concentrations of sodium benzoate (30, 60 and 120 mg/kg body weight) administered by gavage to male albino wistar rats (100 g average weight) over a 14-day period on the plasma levels of aspartate amino transferase and alkaline phosphatase were investigated. Thirty-six (36) male wistar albino rats (average weight of 100 g) were divided into four groups and housed in well-kept cages at the animal house. The rats were fed ad libitum on normal diets while the sodium benzoate solutions in water were given orally at 2-day intervals for 14 days. Blood samples were obtained from sacrificed animals at zero, 2-, 6- and 14-day and levels of plasma enzymes determined by standard methods. The results revealed that for aspartate amino transferase (AST), at 30 mg/kg, enzyme activity (IU/l) increased progressively from 27.33 ± 1.04 on the zero-day to 36.83 ± 1.25 on the 14th day; at 60 mg/kg, the increase was to 38.50 + 0.50 on the 14th day, while the enzyme level increased to 36.40 ± 0.96 on the 14th day at 120 mg/kg of sodium benzoate. The increases were significant (p<0.05) relative to the control. For alkaline phosphatase (ALP), enzyme activity (IU/l) at 30 mg/kg increased from 114.83 ± 0.76 on the zero-day to 130.33 ± 1.04 on the 14th day; at 60 mg/kg, the increase was to 130.16 ± 0.76 on the 14th day, with an increase to 130.00 ± 0.40 noted on the 14thday at 120 mg/kg sodium benzoate. The increase observed for ALP were significant (p<0.05). The findings suggest that short-term administration of sodium benzoate produce notable increases in serum levels of the two enzymes investigated.   Key words: Sodium benzoate, aspartate amino transferase, alkaline phosphatase.