The study investigated the effects of leaves of Bixa orellana L. on some haematological and biochemical indices of albino rats. The dried leaf powder was subjected to extraction with ethanol and the resultant extract further underwent fractionation with n-hexane, chloroform, ethyl-acetate and butanol to yield their respective fractions and the aqueous extract. Preliminary phytochemical screening of the leaf and analysis of the effects of the extracts and fractions on haematological parameters were carried out. Their effect(s) on serum electrolyte concentrations of sodium (Na), potassium (K), bicarbonate (HCO3) and chloride ions (Cl-) was also determined. Median lethal dose (LD50) value of the ethanol leaf extract of Bixa orellana L. was determined in two phases using 45 mice, administered between 10 – 3000mg/kg of the extract. Forty-five albino rats were randomly divided into nine groups of five rats each. Group I served as the control and received 5ml/kg of distilled water, while groups II, III and IV were orally administered with 169.71mg/kg, 339.4mg/kg and 509.1mg/kg of the ethanol extract respectively; the remaining five groups were administered 339.4mg/kg of the butanol, ethyl-acetate, chloroform, n-hexane and aqueous fractions of Bixa orellana for 21 days. Results of the phytochemical screening of Bixa orellana revealed the presence of flavonoids, tannins, terpenes, saponnins and cardiac glycosides. The LD50 value of Bixa orellana when administered intraperitoneally was 1697.06 mg/kg. Ethanol extract of Bixa orellana significantly (P=0.05) decreased the WBC particularly neutrophils, PLT and Na concentration in a dose-dependent manner. It also significantly (P=0.05) increased in a dose-related fashion the RBC, PCV, Hb and K. All the fractions significantly (P=0.05) decreased the PLT and the WBC with the ethyl-acetate fraction showing the most anti-platelet effect. The ethyl-acetate, chloroform and n-hexane fractions significantly (P=0.05) increased the RBC, PCV and Hb. The high dose of ethanol extract, butanol and ethyl-acetate fractions showed a significant (P=0.05) reduction of Na while K was increased significantly (P=0.05) by the low and middle dose of ethanol extract, and n-hexane fraction. These results indicate that Bixa orellana leaf increases RBC, PCV and Hb, decreases WBC and has an anti-platelet effect. The results lend scientific support to some folkloric uses of Bixa orellana leaves in traditional medicine.
Anti-Platelet, Bixa Orellana, Ethanol, Extract, Haematology And Phytochemical