RESUMO
BACKGROUND & OBJECTIVES: Artemisinin isolated from Artemisia annua is the most potent antimalarial against chloroquine resistant Plasmodium falciparum malaria. We previously reported that the ethanolic leaf extract of Artemisia vulgaris, an invasive weed and the only Artemisia species in Sri Lanka, possess both potent and safe antimalarial activity (in terms of antiparasitic properties) in a P. berghei murine malaria model. We report here a prototype study that investigated antidisease activities of A. vulgaris ethanolic leaf extract (AVELE) in a P. berghei ANKA murine malaria model that elicit pathogenesis similar to falciparum malaria. Profound thrombocytosis and thrombocytopenia in mice were detected in early-stage (Day 3), and at a later stage of infection (Day 6), respectively. Plasmodium berghei infected mice, 7 or 8 days post-infection reached end-stage disease with rapid drop in body temperature and usually die within 24 h, as a consequence of cerebral malaria. METHODS: Three doses of the AVELE (500, 750 and 1000 mg/kg) were used to assess antidisease activity of A. vulgaris in terms of survival, effects on thrombocyte related pathology and end-stage disease, antipyretic activity, and antinociception, using standard methodology. RESULTS: The 1000 mg/kg dose of AVELE significantly increased survival, reversed the profound thrombocytopenia/ thrombocytosis (p ≤0.01), altered the end-stage disease (p ≤0.05), and manifested significant antipyretic and antinociceptive (p ≤0.05) activities. INTERPRETATION & CONCLUSION: We conclude that a crude ethanolic leaf extract of A. vulgaris, showed potent antimalarial properties, in terms of antidisease activities; antipyretic activity, peripheral and central antinociception, increased survival, averted end-stage disease and reversed thrombocytopenia/thrombocytosis.
Assuntos
Antimaláricos/uso terapêutico , Artemisia/química , Malária/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Animais , Antimaláricos/isolamento & purificação , Malária/complicações , Malária/patologia , Masculino , Camundongos Endogâmicos ICR , Extratos Vegetais/isolamento & purificação , Análise de Sobrevida , Trombocitopenia/tratamento farmacológico , Trombocitose/tratamento farmacológicoRESUMO
BACKGROUND & OBJECTIVES: Artemisinin isolated from Artemisia annua is the most potent antimalarial drug against chloroquine-resistant Plasmodium falciparum malaria. Artemisia vulgaris, an invasive weed, is the only Artemisia species available in Sri Lanka. A pilot study was undertaken to investigate the antiparasitic activity of an A. vulgaris ethanolic leaf extract (AVELE) in a P. berghei ANKA murine malaria model that elicits pathogenesis similar to falciparum malaria. METHODS: A 4-day suppressive and the curative assays determined the antiparasitic activity of AVELE using four doses (250, 500, 750 and 1000 mg/kg), Coartem® as the positive control and 5% ethanol as the negative control in male ICR mice infected with P. berghei. RESULTS: The 500, 750 and 1000 mg/kg doses of AVELE significantly (p ≤ 0.01) inhibited parasitaemia by 79.3, 79.6 and 87.3% respectively, in the 4-day suppressive assay, but not in the curative assay. Chronic administration of the high dose of AVELE ruled out overt signs of toxicity and stress as well as hepatotoxicity, renotoxicity and haematotoxicity. INTERPRETATION & CONCLUSION: The oral administration of a crude ethonolic leaf extract of A. vulgaris is non-toxic and possesses potent antimalarial properties in terms of antiparasitic activity.