ABSTRACT

Aspartame is a non-nutritive sweetener particularly used in ‘diet’ and ‘low calorie’ products and also in a variety of foods, drugs and hygiene products. The research work aimed at assessing the effect of L-arginine and vitamin C on some antioxidant status and histology of liver and brain tissues of the rats administered aspartame. Wistar albino rats (50-70) g were divided into six (6) group with five (5) rats in each groups. Animals were administered aspartame (1000 mg/kg) and treated with either vitamin C (100 mg/kg) or L-arginine (20 mg/kg and 40mg/kg) respectively. After twenty one (21) days, blood and organ samples were collected for biochemical and histological studies. The results showed that the administration of aspartame caused a significant (p<0.05) increase in liver function indices in the serum, liver and brain homogenates when compared to the normal control group while the co-administration of aspartame with L-arginine and vitamin C showed a significant reduction when compare to the positive control. Total protein concentration showed a significant (P<0.05) increase in the aspartame administered group and co-administration of aspartame and 40 mg/kg of L-arginine when compared with the normal control. While the co-administration of L-arginine 20 mg/kg and 40 mg/kg showed significantly (p<0.05) reduction when compared with the aspartame administered group in the serum, liver and brain. Also a significant (P<0.05) increase in FRAP of serum, brain and liver homogenate of aspartame administered rats was observed when compared with the normal control. The co-administration of aspartame and L-arginine (40 mg/kg) significantly (P<0.05) reduced the FRAP level in the both organs when compared with the normal and positive control. TBARS level significantly (p<0.05) increase in the serum, liver and brain homogenate of aspartame administered rats when compared with the normal control. However, the co-administration of aspartame with vitamin C or different doses of L-arginine (20 mg/kg, 40 mg/kg) respectively caused a significant (P<0.05) reduction. Catalase significantly (p>0.05) increased in the serum, brain and liver homogenate of aspartatme administered rats when compared with the normal control, while the co-administration of aspartame with vitamin C or co-administration of L-arginine (20 mg/kg) and L-arginine administered groups respectively caused a significant (P<0.05) reduction when compared with the positive control and co-administration of L-arginine (40 mg/kg) groups. More so a significant (P<0.05) increase was observed in superoxide dismutase activity of liver and brain homogenate of aspartame administered rats when compared with the normal control, while the co-administration of aspartame with vitamin C (100 mg/kg) and L-arginine (20 mg/kg, 40 mg/kg) respectively caused a significant (P<0.05) reduction when compared with the positive controls. GSH showed a significant (P>0.05) increase in the liver and brain homogenate of aspartame administered rats when compared with the normal control. The co-administration of aspartame with L-arginine (40 mg/kg), vitamin C (100 mg/kg) and L-arginine administration alone showed a significant reduction in the GSH concentration when compared with the positive control group. The histological observation of liver and brain sections administered rats substantiated the biochemical findings. It can be concluded from these observations that consumption of aspartame leads to hepatocellular injury and alterations in brain and serum of antioxidant status and the two antioxidant work to ameliorate adverse effects arising from aspartame administration