Evaluation of naphthoquinones identified the acetylated isolapachol as a potent and selective antiplasmodium agent.

This study reports on the design, synthesis and antiparasitic activity of three new semi-synthetic naphthoquinones structurally related to the naturally-occurring lapachol and lapachone. Of the compounds tested, 3-(3-methylbut-1-en-1-yl)-1,4-dioxo-1,4-dihydronaphthalen-2-yl acetate (1) was the most active against Plasmodium falciparum among both natural and semi-synthetic naphthoquinones, showing potent and selective activity. Compound 1 was able to reduce the in vitro parasite burden, in vitro parasite cell cycle, as well as the blood parasitemia in Plasmodium berghei-infected mice. More importantly, infection reduction under compound 1-treatment was achieved without exhibiting mouse genotoxicity. Regarding the molecular mechanism of action, this compound inhibited the hemozoin crystal formation in P. falciparum treated cells, and this was further confirmed by observing that it inhibits the ß-hematin polymerization process similarly to chloroquine. Interestingly, this compound did not affect either mitochondria structure or cause DNA fragmentation in parasite treated cells. In conclusion, we identified a semi-synthetic antimalarial naphthoquinone closely related to isolapachol, which had stronger antimalarial activity than lapachol.

Antimalarial activity of physalins B, D, F, and G.

The antimalarial activities of physalins B, D, F, and G (1-4), isolated from Physalis angulata, were investigated. In silico analysis using the similarity ensemble approach (SEA) database predicted the antimalarial activity of each of these compounds, which were shown using an in vitro assay against Plasmodium falciparum. However, treatment of P. berghei-infected mice with 3 increased parasitemia levels and mortality, whereas treatment with 2 was protective, causing a parasitemia reduction and a delay in mortality in P. berghei-infected mice. The exacerbation of in vivo infection by treatment with 3 is probably due to its potent immunosuppressive activity, which is not evident for 2.

Avaliação da toxicidade de materiais endodônticos em células-tronco da polpa dentária / Toxicity evaluation of endodontic materials in dental pulp stem cells

O objetivo deste trabalho foi avaliar ao efeito citotóxico doHidróxido de Cálcio, Paramonoclorofenol Canforado, Otosporin eFormocresol diluído em células-tronco da polpa de dente permanentehumano (DPSC). As DPSC foram semeadas em placa decultura na concentração de 1,5X104 células/poço. Foram feitasdiluições das drogas em 1:9, 1:27 e 1:81 e deixadas em contatocom as células por 2 horas, sendo que o grupo controle foi mantidoem DMEM completo. As células foram lavadas com soluçãosalina duas vezes. Foram realizadas avaliações do metabolismo(MTT). Concluiu-se que o Hidróxido de Cálcio e o Otosporinforam as drogas menos tóxicas para as DPSC, enquanto que oParamonofenol Canforado e o Formocresol foram letais em todas asconcentrações.

The aim of this paper was analyze the cytotoxicity effect ofCalcium Hydroxide, Paramonoclorofenol Canforado, Otosporinand Formocresol deluded in dental pulp stem cells (DPSC).Material and Methods: DPSC were grown in 96 wells cultureplate in the concentration of 1.5 X104 cells per well. Dilutionsof drugs were as followed: 1:9, 1:27 and 1:81, and control withDPSC in DMEM. The cells were cultured for an additional 2hours. The cells were washed with bufferin saline solution for2 times and MTT test was performed. Results: The Ca(OH)2and Otosporin were the drugs less toxic to the DPSC, while theParamonophenol Canforated and formocresol were lethal in allconcentrations. Conclusions: all drugs tested were toxic to theDPSC.

Ryanodane diterpenes from two Erythroxylum species.

Ryanodane diterpenes, named 14-O-methyl-ryanodanol and ryanodanol, were isolated from ripe fruit of Erythroxylum passerinum. Compound 2 was also found in the leaves of this species, while 1 was obtained from the leaves of E. nummularia. Compound 1 showed insecticidal activity against Aedes aegypti larvae.