ANTIPLASMODIAL ACTIVITY AND IMMUNOMODULATORY EFFECTS OF ETHANOLIC LEAF EXTRACT OF TITHONIA DIVERSIFOLIA (HEMSL) IN SWISS ALBINO MICE

Abstract

This study on the antiplasmodial activity and immunomodulatory effects of ethanolic leaf extract of Tithonia diversifolia in Swiss Albino mice was carried out from July, 2015 to January, 2016. Standard methods were used to determine the phytochemicals, acute toxicity, antiplasmodial activity, haematological assay, serum biochemical assay and histopathological effect of ethanolic leaf extract of T. diversifolia in Swiss albino mice. Qualitative screening revealed the presence of saponin, alkaloid, flavonoid, tannin and cardiac glycoside while the quantitative screening revealed the presence of tannin (0.39mg/100g), flavonoid (0.87mg/100g), cardiac glycosides (1.19mg/100g), alkaloid (1.23mg/100g) saponin (1.37mg/100g). The toxicity test showed no mortality at highest dosage of 1600mg/kg body weight administered. Thirty experimental mice were randomly distributed into 6 groups for antiplasmodial activities. Groups 1, 2 and 3 were infected with P. berghei and treated with 0.2mL of 200mg/kg, 400mg/kg and 600mg/kg body weight of T. diversifolia extract respectively. Group 4 (positive control) was infected with P. berghei and treated with 0.2mL of 5mg/kg body weight of chloroquine. Group 5 (negative control) was infected with P. berghei and treated with 0.2 mL of normal saline and group 6 (normal control) was not infected and administered with 0.2mL of normal saline. The ethanolic leaf extract of T. diversifolia produced percentage chemo-suppression of parasitaemia of 60.02%, 63.45% and 92% at doses of 200mg/kg, 400mg/kg and 600mg/kg body weight in groups 1, 2 and 3 respectively. Group 4 (positive control) and group 5 (negative control) having 100% and 0.0% chemo-suppression respectively. The red blood cells, white blood cells, packed cell volume, platelets and haemoglobin concentration of experimental mice in extract treated groups (1-3) were significantly (P<0.05) higher than negative control group. Treatment with extract of T. diversifolia produced significant reduction in alanine amino transferase (ALT) and cholesterol in groups 1-3. The highest CD4 count of 49.25μl/cell was observed in group 2 while the least value of 22.25μl/cell was recorded in group 5. The histopathological evaluation of liver and kidney in this study revealed varying degree of abnormal cellularity though, the activities of ethanolic leaf extract of T. diversifolia at 400mg/kg body weight revealed the kidney and liver of mice with normal glomeruli and hepatocytes. This study has shown that the ethanolic leaf extract of T. diversifolia was able to suppress the parasitaemia in the infected mice and enhancing the immune system.