Summary: Sulphadoxine-pyrimethamine (SP) despite reported resistance
remains an important drug of choice for the treatment and control of
malaria in most endemic areas. Exacerbation of intra-erythrocytic
oxidative stress might contribute to the process of elimination of
malaria parasites in the body. The effect of treatment with SP on the
antioxidant defense system was investigated using rabbit as a model.
Ten male rabbits were divided into two groups of five animals each. The
first group was administered with normal saline and served as control.
The second group received a single dose of SP (26.25mg/kg body weight).
Blood samples were collected before and at 6, 12 and 24 h after drug
administration. Activity of cellular enzymatic antioxidants, superoxide
dismutase (SOD) and catalase (CAT), and level of reduced glutathione
(GSH) were assayed using standard spectrophotometric methods. Serum
lipid peroxidation was assessed by the formation of thiobarbituric acid
reactive species (TBARS) while protein content was assayed by the
method of Lowry et al., 1951. SOD activity was observed to increase
progressively by 4.9, 63.4 and 120.8% at 6, 12 and 24 h respectively,
after drug administration. Similarly, CAT activity increased by 44.5,
82.6 and 116.3% at 6, 12 and 24 h, respectively. TBARS level also
increased significantly by 45.5, 118.2 and 186.4%, respectively.
However, the level of GSH decreased by 41.9% at 6 h and remained so up
till the 12 h, but by 24 h after drug administration, the level of the
thiol substance has increased considerably up to 48.4% above the
baseline level. SP treatment altered the antioxidant defense system in
blood and may therefore induce oxidative stress by generating reactive
oxygen species. This might play significant role in the therapeutic and
adverse effects associated with the drug