title: Si-Accumulation InArtemisia annuaGlandular Trichomes Increases Artemisinin Concentration, but Does Not Interfere In the Impairment ofToxoplasma gondiiGrowth.
abstract: Artemisia annuais used as a source of artemisinin, a potent therapeutic agent used for the treatment of infectious diseases, chiefly malaria. However, the low concentration (from 0.01 to 1.4% of dried leaf matter) of artemisinin in the plant obtained with the traditional cropping system makes it a relatively expensive drug, especially in developing countries. Considering that artemisinin and silicon (Si) are both stored inA. annuaglandular trichomes, and that Si accumulation has never been investigated, this study aimed to look into Si effects onA. annuatrichome artemisinin concentration, and whether leaf infusion from Si-treatedA. annuaplants is able to controlToxoplasma gondiigrowth.T. gondiiis the etiologic agent of toxoplasmosis, a zoonotic parasitic disease whose traditional treatment shows significant side effects. The experimental design consisted ofA. annuaseedlings randomly planted in soil treated with different doses of calcium/magnesium silicate (0, 200, 400, 800, and 1600 kg ha-1). Analysis of foliar macronutrients showed significant increases of nitrogen content only at the highest dose of silicate. Foliar micronutrients, Si concentrations, and plant height were not affected by any of the silicate doses. However, the dose of 400 kg ha-1of silicate increased the trichome size, which in turn raised artemisinin concentration in leaves and the infusion. In contrast, the 800 and 1600 kg ha-1doses dramatically decreased artemisinin concentration. HeLa cell treatment with the infusion ofA. annuagrown in soil treated with 400 kg ha-1of silicate decreased parasite proliferation in a dose-dependent manner when the treatment was carried out after or along withT. gondiiinfection. However, this effect was similar toA. annuagrown in soil without silicate treatment. Thus, it can be concluded that, even though Si applied to the soil at 400 kg ha-1has a positive effect on theA. annuaglandular trichome size and the artemisinin concentration, this outcome cannot be directly associated with the efficiency ofA. annuainfusion onT. gondiigrowth, suggesting that other components fromA. annualeaves could be acting in synergy with artemisinin.
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Cristina
authors.initials: C
authors.lastname: Rostkowska
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Mota
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Taísa C
authors.initials: TC
authors.lastname: Oliveira
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Santiago
authors.affiliation: Fertilizer Technology Laboratory, Institute of Agricultural Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Lilian A
authors.initials: LA
authors.lastname: Oliveira
authors.affiliation: Fertilizer Technology Laboratory, Institute of Agricultural Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Gaspar H
authors.initials: GH
authors.lastname: Korndörfer
authors.affiliation: Fertilizer Technology Laboratory, Institute of Agricultural Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Regina M Q
authors.initials: RM
authors.lastname: Lana
authors.affiliation: Laboratory of Plant Histopathology and Structural Biology of Plants, Center for Nuclear Energy in Agriculture, Universidade de São Paulo Piracicaba, Brazil.
authors.forename: Monica L
authors.initials: ML
authors.lastname: Rossi
authors.affiliation: Laboratory of Plant Histopathology and Structural Biology of Plants, Center for Nuclear Energy in Agriculture, Universidade de São Paulo Piracicaba, Brazil.
authors.forename: Neusa L
authors.initials: NL
authors.lastname: Nogueira
authors.affiliation: Mediplant, Swiss Research Centre on Medicinal and Aromatic Plants Conthey, Switzerland.
authors.forename: Xavier
authors.initials: X
authors.lastname: Simonnet
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Tiago W P
authors.initials: TW
authors.lastname: Mineo
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: Deise A O
authors.initials: DA
authors.lastname: Silva
authors.affiliation: Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Universidade Federal de Uberlândia Uberlândia, Brazil.
authors.forename: José R
authors.initials: JR
authors.lastname: Mineo
keywords: Artemisia annua; Toxoplasma gondii; artemisinin; herbal medicine; silicon