Extracts from Ajuga Remota and their In Vivo Antimalarial Activity Against Plasmodium Berghei in Mice

Abstract

Aqueous crude extracts of Ajuga remota which have been traditionally used to treat fevers and other ailments, were treated in vivo against Plasmodium berghei malaria infections in mice using the four—day suppressive test. Ajuga remota leaves, stems, roots or flowers were either boiled wet in water immediately after collection or dried first before boiling in water and then injected (3Omg/kg day”) intravenously through the tail vein of mice infected with P. berghei. Chloroquine (30mg/kg day“) was used as a control standard antimalarial drug. On day four, parasitized blood smears were made from tail strip for determination of parasitaemia and calculation of percent suppression. The different parts of Ajuga remota showed different suppressive activities of E; berghei parasites in mice with the wet plant preparations showing higher activities than the dry plant preparations. The leaves showed the highest antimalarial activity (90.4%, 82.8%) compared to the stems (33.5%, 26.9%), roots (44.0%, 31.1%) and the flowers (34.9%, 17.2%) for wet and dry parts, respectively. Chloroquine showed 84.7% suppression of parasitaemia. The results showed that A. remota has potential antimalarial principals and for further evaluation in determining the activity against malaria parasites, the wet leaves extract with the highest suppressive activity was separated into the basic, acidic, and neutral components by the use of chemically active solvents. They were tested for the antimalarial activity at a dosage of 30mg/kg day“ per mouse for four days. The basic component had the highest antimalarial activity (67.8%) as compared to neutral (64.8%) and acidic (46.9%) components. The basic and neutral components were fractionated in a column to give various fractions. The basic component gave five fractions with no good separation whereas neutral component gave two fractions, one with one spot and the other with only two spots. The fraction 2 of the neutral component (one spot) with Rf = 0.94 had the highest antimalarial activity (61.5% suppression) as compared to fraction 1 (two spots) (38.5% suppression). The fractions were administered to the mice at 30mg/kg day" dosage similar to that of chloroquine powder which gave 84.6% suppression of parasitaemia.