Evaluation of in vivo antitrypanosomal activity of crude extracts of Artemisia abyssinica against aTrypanosoma congolense isolate

Abstract

BackgroundAfrican trypanosomiasis is a major disease of economic and public health importance affecting agricultural and human development. The search for alternative compounds against African trypanosomiasis is justified by various limitations of existing chemotherapeutic agents. This study was aimed at screening the hydromethanolic and dichloromethane (DCM) crude extracts of aerial parts of Artemisia abyssinica for in vivo antitrypanosomal activity against Trypanosoma congolense isolate in mice.MethodsThe aerial parts of the plant were extracted by maceration technique using dichloromethane and 80% methanol to obtain the corresponding crude extracts. The plant extracts at doses of 100, 200 and 400 mg/kg body weight were administered intraperitoneally daily for 7 days to mice infected with Trypanosoma congolense. Diminazene aceturate and distilled water were used as positive and as negative controls respectively. The level of parasitaemia, body weight, packed cell volume, differential leukocyte counts and mean survival period were monitored.ResultsThe study showed that the DCM extract at 200 and 400 mg/kg, and the hydromethanolic extract at 400 mg/kg reduced parasitaemia (p < 0.05), ameliorated anaemia (p < 0.05), prevented body weight loss (p < 0.05) and resulted in significant increase in neutrophil levels (p < 0.05) and marked decrease in lymphocyte levels (p < 0.05) compared to the negative control.ConclusionsThis study established that aerial parts of A. abyssinica have antitrypanosomal potential and can be considered a potential source of new drugs for the treatment of tropical diseases caused by trypanosomes.

In Vivo anti-trypanosomal activity of dichloromethane and methanol crude leaf extracts of Dovyalis abyssinica (Salicaceae) against Trypanosoma congolense

“…Higher doses (250 and 200 mg/kg) of both extracts substantially reduced parasitemia level in mice, despite the failure to completely clear bloodstream form of the parasite. The result is consistent with other reports [ 25 , 28 ] that medicinal plants reduce parasitemia. The effect might be attributed to the presence in them of one or more of secondary metabolites which may exert their effects through the additive or synergistic action of several chemical compounds acting at a single or multiple target sites associated with a physiological process [ 29 , 30 ].…”

“…This may be credited to the presence of phenolic compounds in the DCM, but not in the MOH, extract as these compounds were shown to exhibit anti-trypanosomal activity [ 39 ]. Other report has shown similar observation that superior activity was obtained from the DCM plant extracts [ 28 ].…”

“…The observation that parasitemia was relatively elevated and that trypanosomes were persistently present in blood of extract treated animals after withdrawal of treatment (day 12, 14) may suggest recovery of the parasites from the suppressive effect of the extracts. This resurgence in mean parasitemia may be due to the waning effect of the treatment [ 28 ] or the release of trypanosomes from the tissues which can occur when treatment is delayed or the dose rate is inadequate [ 22 ]. Despite the temporary clearance of blood stream forms of trypanosomes, relapse occurred in all mice treated with diminazene aceturate at day 12 post-treatment initiation.…”

“…Mortality was monitored daily and the number of days from the time of inoculation of the parasite up to death was recorded for each mouse in the treatment and control groups throughout the follow up period for 6 weeks [ 28 ].…”

Novel trypanocide from an extract of Pleurotus sajor-caju against Trypanosoma congolense

“…The cure rate of animals treated with 250 mg/kg of the extract was 100% and the animals remained aparasitemic for more than 60 days post infection. This is remarkable because previous studies (Ekanem et al 2008;Abu & Uchendu 2011;Tsegabirhan et al 2014;Feyera et al 2014) reported relapse when mice infected with trypanosomes are treated with either plant extracts or the commercial trypanocide (diminazine aceturate). For instance, Feyera et al (2014) reported that 400 mg/kg dichloromethane and 80% methanol extracts of Artemisia abyssinica Sch.…”