Clinical research of plant extracts in the treatment of malaria from standardized raw material: Artemisia annua (VAR.CPQBA)

• Grant number: 09/53639-3
• Support Opportunities: Research Projects - Thematic Grants
• Start date: November 01, 2010
• End date: May 31, 2013
• Field of knowledge: Biological Sciences - Parasitology
• Agreement: CNPq - Pronex - Malaria Network
• Principal Investigator: Pedro Melillo de Magalhães
• Grantee: Pedro Melillo de Magalhães
• Host Institution: Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas (CPQBA). Universidade Estadual de Campinas (UNICAMP). Paulínia , SP, Brazil

Abstract

The traditional use of Artemisia annua leaves as antimalarial tea, which species was recently improved on rich and standardized genotypes to more than 1% of artemisinin, has scientifically proof its therapeutic potential for falciparum malaria. In this research, is proposed to assess the level of such potential in relation to the treatment of greater effectiveness in the current decade, the combination artemether-lumefantrine (Coartem ®). The study followed official protocol approved by the National Research Ethics (CONEP), with rigorous clinical control of 17 patients with non-severe falciparum malaria recruited in three cities of Pará State in Brazil: Tucuruí, Goianésia do Pará, and Anajás. The tea group received it prepared in a ratio of 1.25 g of dried leaves A. annua variety CPQBA with 1% artemisinin in 250mL boiling water every 6 hours for 7 days, totaling approximately 175mg of artemisinin, while the control group, artemether-lumefantrine (Coartem ®), received the equivalent of 525mg of artemisinin in 3 days. The results showed that parasitemia performance in tea group was similar to that described in the literature when pure artemisinin is used at a total dose of 525mg, ie the same negative parasitemia in the first days occurred in tea group even being administered in 1/3rd of artemisinin dose. However, also as occurred in monotherapy with artemisinin or artesunate, 57.1% of patients treated with A. annua tea were resistant type I, with return of parasitemia by day 14 or 21 during the cure control. In the other patients there were resistance Type II / III, and, besides without symptoms of gravity, they all were rescued by artemether-lumefantrine (Coartem ®) according to the protocol reaching subsequent negative parasitemia. The fact of effectiveness of tea to be similar to that of artemisinin with only 1/3rd of its dose, infers that other compounds present in the crude extract, probably flavonoids, have contributed to negative parasitemia. Considering the known excellent therapeutic response from artemether-lumefantrine, future research with A. annua tea must also use the same strategy of combination with another antimalarial to perpetuate its therapeutic action or other forms of administration. Therefore, we believe that the appropriate address to future actions on A. annua tea involve: 1) At this stage we would not encourage its use by the population because although the patients have had excellent clinical response was observed upsurge Resistance (type I) or no decrease or increase in parasitemia (Resistance type II / III) during its administration, and 2) Search for combinations or associations to improve their effectiveness. This research fits into the context of clinical study of medicinal plants mainly from Brazilian flora with potential for malaria treatment, as infusion form, which has high adhesion by local people and, thus, of great importance is the continuing search for species that may be associated with the crude extract of A. annua to increase its antimalarial efficacy.(AU)