This study analysed the effect of insecticidal oils obtained from the leaves of Cassia occidentalis and Euphorbia milii on haematological indices in rats. It also evaluated the extent ethyl ether anaesthesia affects the concentration of haematological indices in experimental rats. Oils were extracted from both plants via soxhlet and administered to Wistar rats orally once a week, for 2 weeks. Fifty-six rats were divided into two groups (28 rats each), these were further divided into seven (7) groups of four rats each. The control group (A) received feed and water only, Groups B1, B2, and B3 received 1500 mg/kg, 3000 mg/kg and 5000 mg/kg body weight of C. occidentalis oil extract, respectively, and similarly, groups C1, C2 and C3 received 1500 mg/kg, 3000 mg/kg and 5000 mg/kg body weight of E. milii oil extracts. The first set was sacrificed under mild ethyl ether anaesthesia, while the second set was sacrificed without any anaesthetic agent. Thereafter, whole blood was drawn and analysed for changes in haematological indices. Both oils caused a significant (P < 0.05) decrease in white blood cells (WBC) and platelet counts at 5000 mg/kg body weight relative to the control in both unanaesthetised and anaesthetised rats. In addition, a significant decrease in MCH, MCHC and in Red Blood Cell counts and Packed Cell Volume was also observed in unanaesthetised rats exposed to E. milii oil and C. occidentalis oil respectively at 5000 mg/kg body weight relative to the control. Since insecticides are usually applied at much lower concentrations, the plant oils may be considered safe for use as insecticidal agents.
Keywords: Biochemistry; Cell biology; Immunology; Molecular biology; Plant biology; Toxicology.