PHYTOCHEMICAL SCREENING AND IN VIVO ANTIMALARIAL ACTIVITY OF THE METHANOL LEAF EXTRACT OF TAPINANTHUS DODONEIFOLIUS (DC) DANSER GROWING ON VITEX DONIANA

Malaria is a major public health problem in the world especially in Africa, with an estimated two million 

children and pregnant women worldwide dying of malaria yearly, primarily because of Plasmodium 

falciparum and its complications. Preliminary phytochemical screening of the methanol leaf extract revealed the presence of triterpenoids, saponins, tannins, terpenoids, flavonoid, cardiac glycoside, 

carbohydrate and alkaloids. The in vivo antimalarial activity of the crude methanol leaf extract of Tapinanthus dodoneifolius against plasmodium berghei berghei infection was investigated in this study using suppressive test and curative test. In the suppressive test; after 3 hours of infection with the parasite, 25 mice were randomly selected and assigned into treatment groups of five containing five mice in each group and treated for four days. Group 1-3 mice received 75mg/kg, 150mg/kg and 300mg/kg body weight of the extract respectively, while the 4th and 5th group received 5mg/kg of chloroquine and 2ml/kg of distilled water and serves as positive and negative control respectively. In the curative test, the mice were infected with the parasite and left for 72 hours for parasitaemia to develop and they were randomly divided into five groups each containing five mice in each group. After 72 hours (day 4), group 1-3 mice received 75mg/kg, 150mg/kg and 300mg/kg body weight of the extract respectively, while the 4th and 5th group received 5mg/kg and 2ml/kg of chloroquine and distilled water as positive and negative control respectively. The crude methanol leaf extract of Tapinanthus dodoneifolius significantly (p< 0.05) produced a dose dependent chemo-suppression on the plasmodium berghei berghei in both the early and established infection. At doses of 75, 150 and 300mg/kg body weight, the extract produced chemo-suppression of 57.22%, 60% and 66.6% for the early infection(suppressive test) and 60%, 65.6% and 71% for the established infection(curative test) respectively. The level of the percentage chemo-

suppression produced at the lowest dose 75mg/kg (60%) in the curative studies was equivalent to the higher dose in suppressive test. The standard drug agent, chloroquine at dose of 5mg/kg produced the highest parasite suppression (81.6%) and curation (91.4%) when compared with the negative control 

because chloroquine is a pure antimalarial compound. The liquid median oral lethal dose (LD50) value was found to be greater than 5000mg/kg body weight at the tested dose, suggesting that the crude extract is practically non-toxic. This provides some scientific rational for the ethnomedical claim of the use of the plant in the treatment of malaria.