Abstract
Introduction: Immunosuppression by pharmaceutical drugs or ultraviolet radiation is dose-dependent and usually transient, while infection with certain pathogens, such as malaria parasites, is persistent, and the resultant immune deficiency is progressive unless the infection is treated. Effective dose of dexamethasone that can bring about immunosuppression in female Wistar rats was therefore examined in this study. Methodology: Fifteen rats weighing 130 ± 20 g were randomized into three groups. Group 1 (negative control) was placed on distilled water and rat pellets only, group 2 (20 mg/kg dexamethasone & 10 mg/kg weekly booster dose dexamethasone), while group 3 (20 mg/kg initial dose & 10 mg/kg daily booster dose). All treatments were for 14 days. The rats were sacrificed, blood collected for biochemical and haematological assessments. Results: Total protein and albumin levels were higher significantly in the test groups in comparison with negative control. The difference in the levels of globulin among the three groups was not significant (p>0.05). The decreased levels of white blood cells count, percentage lymphocytes, eosinophils and platelet count in the test groups were significant when compared with the control, while the percentage neutrophils were significantly increased in the test groups. The differences in the packed cell volume and the haemoglobin content were not significant. Conclusion: The altered biochemical and haematological parameters in the test groups suggest that dexamethasone is an effective immunosuppressive agent particularly at 20mg/kg initial dose and 10mg/kg weekly booster dose