In vitro and in vivo antimalarial activity of the volatile oil of Cyperus articulatus (Cyperaceae)

Malaria is a disease of global tropical distribution, being endemic in more than 90 countries and responsible for about 212 million cases worldwide in 2016. To date, the strategies used to eradicate this disease have been ineffective, without specific preventive measures such as vaccines. Currently, the existing therapeutic arsenal is limited and has become ineffective against the expansion of artemisinin-resistant Plasmodium, demonstrating the need for studies that would allow the development of new compounds against this disease. In this context, we studied the volatile oil obtained from rhizomes of Cyperus articulatus (VOCA), a plant species commonly found in the Amazon region and popularly used as a therapeutic alternative for the treatment of malaria, in order to confirm its potential as an antimalarial agent by in vitro and in vivo assays. We cultured Plasmodium falciparum W2 (chloroquine-resistant) and 3D7 (chloroquine-sensitive) strains in erythrocytes and exposed them to VOCA at different concentrations in 96-well microplates. In vivo antimalarial activity was tested in BALB/c mice inoculated with approximately 106 erythrocytes infected with Plasmodium berghei. VOCA showed a high antimalarial potential against the two P. falciparum strains, with IC50 = 1.21 µg mL-1 for W2 and 2.30 µg mL-1 for 3D7. VOCA also significantly reduced the parasitemia and anemia induced by P. berghei in mice. Our results confirmed the antimalarial potential of the volatile oil of Cyperus articulatus. (AU)

Avaliação do potencial antioxidante e anti-Helicobacter pylori in vitro de extratos de plantas medicinais utilizadas popularmente na região amazônica / Evaluation of antioxidant and anti-Helicobacter pylori in vitro potential of medicinal plant extracts popularly used in Amazon

Na região amazônica, ainda que não conclusivo, estima-se a existência de aproximadamente 60.000 espécies de plantas contribuindo para uma vasta riqueza natural. Considerando essa estimativa, são necessários investimentos em ciência e tecnologia, proteção e valorização dos recursos naturais e, principalmente, a importância dos conhecimentos tradicionais associados à biodiversidade (Albagli, 2010). O conhecimento tradicional tem fornecido informações valiosas para a descoberta de novos agentes antimicrobianos a partir das plantas (Duraipandiyan, Ayyanar e Ignacimuthu, 2006), destacando a importância da medicina popular na busca por moléculas eficazes contra micro-organismos cada vez mais resistentes (Lopez, Hudson e Towers, 2001), como por exemplo Helicobacter pylori.(AU)

The Amazon region has an enormous diversity of plant species, which contributes to its known vast natural wealth. In this context, the aim of this work was to evaluate the antioxidant, anti-Helicobacter pylori and antiurease potentials of medicinal plant extracts popularly used in the western Pará, northern Brazil. Antimicrobial assays were carried out using spectrophotometric broth microdilution technique, the antioxidant potential by the DPPH and ABTS•+ assays and anti-urease activity by inhibition of the enzyme urease. The ethanolic extract of leaves of Schnella sp. showed the best antioxidant potential in both methods, with IC50= 6.35 µg/mL (DPPH) and 1.81 µg/mL (ABTS•+) and the highest percentage of inhibition of urease (45%) at 1024 µg/ml. The ethanolic extract of the resin of "breu-branco" inhibited 82.8% (512 µg/mL) of the bacterial growth. These results together show the potential of the plant species used in the western Pará, in the search for molecules with antioxidant and antimicrobial action.(AU)