The role of intraperitoneally administered vitamin C during Trypanosoma congolense infection of rabbits

Abstract

The effects of daily intraperitoneally administered doses of 100 mg/kg bd. wt. vitamin C on levels of some endogenous antioxidants as well as hepatic and renal function were investigated in a group of rabbits infected with a strain of Trypanosoma congolense (strain number: BS2/TC /SP28/P4). Values of parameters estimated in this group during and after 5 weeks of infection were compared with those from a group of similarly infected, but vitamin-free rabbits as well as two groups of healthy rabbits, one group of which was similarly treated with vitamin C. T. congolense infection caused significant (P<0.01) decrease in packed cell volume (PCV), blood and organ glutathione, plasma and liver ascorbic acid as well as serum creatinine. Treatment of infected animals with vitamin C kept the parasitaemia significantly (P<0.01) lower than in the vitamin-free infected animals after the 3rd week of infection. The vitamin treatment also prevented, to a significant (P< 0.01) degree (and in some cases completely), the disease-induced decreases in blood and organ glutathione (GSH) as well as plasma ascorbic acid. The trypanosomal anaemia was partially, but significantly (P<0.01) ameliorated by vitamin treatment. Infection without vitamin therapy also caused significant (P<0.01) increase in the levels of serum total bilirubin and proteins as well as aspartate and alanine aminotransferases. Vitamin C completely, or to a significant (P<0.01) degree, prevented the disease-induced increases in all these parameters. It was concluded that vitamin C at the dose and route used prevented the disease-induced depletion of endogenous antioxidants, hepatic dysfunction and to a significant degree, anemia.

Key words: Trypanosoma congolense, antioxidant, oxidative damage.