Evaluation of the Curative Potentials of Methanol Extract of Citrus aurantifolia Leaves in Plasmodium berghei - infected Mice

Abstract

Malaria remains a public health problem, with most front line drugs not able to clear parasite infection completely due to parasite resistance. With the increased tempo in the search for new chemotherapeutic agents against malaria, the use of medicinal plants by extracting active principles still remains the most appealing option. Phytochemical screening and in vivo antiplasmodial potential of methanol extract of Citrus aurantifolia leaves in Plasmodium berghei infected mice were carried out using standard methods. Infected mice were grouped into five groups of five mice each. Treatment commenced 72 hours post infection and lasted for five consecutive days, with daily parasitaemia levels monitored. The packed cell volume (PCV) of the experimental animals was also monitored before infection, before the commencement of treatment and after treatment. Three groups A, B and C were administered 200, 400 and 600 mg/kg body weight (b.w) of methanol extract of Citrus aurantifolia leaves respectively. Group D was administered 5 mg/kg b.w Chloroquine (standard drug). Group E was left untreated, while a sixth group of five mice was not infected and not treated. The animals were also monitored for any mortality for a period of 28 days and the mean survival time calculated in days. The methanol extract of Citrus aurantifolia leaves was found to contain tannins, steroids, terpenoids, glycosides, anthraquinones and flavonoids. The percentage parasite inhibition as well as the mean survival time were calculated to be (50.51 %, 12.67±1.45 days), (57.78 %, 17.33±0.88 days), (63.59 %, 22.67±0.67 days) and (70.67 %, 28.33±0.88) for groups treated with 200, 400, 600 mg/kg b.w of the extract and 5 mg/kg b.w of chloroquine respectively. There was no significant difference in percentage packed cell volume after treatment. The results obtained from this study indicate that Citrus aurantifolia leaves have appreciable antiplasmodial activity against Plasmodium berghei infected mice in a dose dependent manner. However, bioactive-guided purification of the crude extract could bring about specific bioactive compound(s) for antiplasmodial activity which could result in a much higher percentage parasite inhibition.