Standard 20 microscope

The antiplasmodial or curative potency of crude extracts of leaves and stem-bark of M. lucida was studied using curative or Ranés test according to the method of Ryley and Peters (1970). An aliquot or standard inoculum (1 × 10⁷) of parasitized red blood cell collected from donor mice was intraperitonially injected into each experimental mice on day 1 (D0). The parasitized was allowed to establish for four days (96 h) (D₄). A drop of tail blood was taken from each mice every 24 h through treatment period (D₄ – D₈). On day four (D₄), tail blood was taken before dosage of plant extracts were administered. The parasitized blood was fixed and stained with methanol and Giemsa on a slide. Each mice in group I to XII were treated with 200 or 400 mg kg⁻¹ crude extract (0.2 mL) while group XIII and XIV were treated with 0.2 mL chloroquine and distilled water respectively (D4 – D8). The amount of parasitaemia in blood samples before or during treatment were counted using 100x oil immersion lens of a Zeiss Standard 20 microscope (Carl Zeiss LTD, Welwyn Garden City, UK). The average parasitaemia and mean percentage inhibition were calculated using the formula below: $\text{Average}\text{\%}\text{parasitaemia}=\frac{\mathit{Number}ofparasitizederythrocytes\times 100}{\mathit{Total}numberoferythrocytes}$ $\text{\%}\text{Inhibition}=\frac{\text{\%}parasitaemiacontrol-parasitaemiatreatedgroup\times 100}{\mathit{parasitaemia}incontrolgroup}$