ABSTRACT

Combretum racemosum (P. Beauv.) commonly known as “Christmas rose” in Southern Nigeria local English is a plant that has been in use for several years by African traditional healers in the treatment of haemorrhoids, convulsive coughing, tuberculosis, toothache, male sterility and as condiments in soups. This study was designed to evaluate the in vitro antioxidant and diuretic activities ofthe ethanolic extract of C. racemosum leaves on experimental model albino rats. The acute toxicity (LD50) of C. racemosum leaves was carried out on the albino rats using standard method. The result showed a lethal dose (LD50) > 5500mg/kg of the extract. In the in vitro antioxidant test, there was a concentration dependent increase in the percentage (%) scavenging activity when compared with the Vitamin C (control) for 2,2-diphenyl-l-picrylhydrazyl (DPPH), Nitric oxide and Anti-lipid peroxidation activity of C. racemosum leaves. The result exhibited a significant difference at higher concentration when compared to the control. The IC50 values of the plant extract were observed which measures its antioxidant effectiveness. The ethanolic extract also exhibited a significant increase in urine volume and the electrolyte at different concentration from 187.5mg/ml to 3000mg/ml. At 3000mg/ml (0.7 ± 0.14) and 1500mg/ml (0.45 ± 0.07) concentrations, the extract exhibited a significant difference in sodium (Na*) excretion (87.4 ± 1.70) and (76.65 ± 0.49) respectively. The potassium (K+), chloride (Cf) and bicarbonate (HCO3’) level decreases as the concentration decreases from 3000mg/ml to 187.5mg/ml. The decrease in the electrolyte level as the concentration of the doses decreases exhibited a significant difference (P<0.05). From the result generated, the ethanolic extract of C. racemosum leaves is an effective natural antioxidant and can induce diuresis at very high dosage.