Antioxidative and Toxicological Evaluation of Ethanol Extract of Cola Hispida Pod

Abstract

The pod of Cola hispida commonly known as ‘monkey kola’ was studied for its antioxidative potential and toxicological effect. Phytochemical screening of the ethanol extract was carried out, and it was also analysed for its proximate composition. A total of thirty two (32) animals were used for the study. The sub-chronic toxicity study was divided into two phases, 14 and 28 days of administration respectively. Sixteen (16) male albino rats were used for each of the phases, and were randomly divided into four groups of four (4) rats each. Group 1 was the normal control, while Groups 2, 3 and 4 received 100 mg/kg, 200 mg/kg and 400 mg/kg b. w. of the extract respectively. The extract was orally administered using oral intubation tube. Result of the preliminary studies revealed the presence of alkaloids, flavoniods, saponins, tannins, and polyphenol. The most abundant proximate constituent was carbohydrate (54.07 ± 8.21 %). The following biomarkers of toxicity were evaluated: creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein, urea, and creatinine. At days 14 and 28, there were significant (p < 0.05) increase in CK concentrations in the groups that received graded doses of ethanol extract of Cola hispida pod (CHPE) compared to the normal control, while there was no significant (p > 0.05) increase in LDH and AST levels. The antioxidant enzymes assayed were catalase (CAT), gluthatione peroxidase (GPx), and superoxide dismutase (SOD). At both 14 and 28 days, there was a non significant (p > 0.05) increase in CAT and SOD, while there was a significant (p < 0.05) increase in GPx for the group that received 200 mg/kg b. w. extract. There was a significant (p < 0.05) increase in ALT level for the group that received 400 mg/kg b. w. extract, and a significant (p < 0.05) decrease in total protein of the groups that received graded doses of the extract compared to the normal control. Also, there was significant (p < 0.05) increase in the urea concentration of the groups that received 200 and 400 mg/kg b. w. extract. A non significant (p > 0.05) increase in creatinine concentration was observed in the groups that received the graded doses of the extract when compared to the normal control. There was a non significant (p > 0.05) increase in the lipid profile (TChol, TAG, LDL and HDL) as the doses of the extract increased from 100 to 400 mg/kg b. w. Also, there was no significant (p > 0.05) difference in the haematological indices evaluated (Hb, RBC, WBC, and PCV). There was significant (p < 0.05) increase in malondialdehyde concentration in the groups that received graded doses of the extract compared to the normal control. Histological studies of the liver after 28 days showed some enlarged hepatocytes compared to normal sized hepatocytes for the group that received 200 mg/kg b. w. CHPE. This study revealed the toxicity of Cola hispida pod if used over a long period of time.