Cytotoxic and genotoxic effects of Solanum lycocarpum St. -Hil (Solanaceae) on the cell cycle of Lactuca sativa and Allium cepa / Efeito citotóxicos e genotóxicos de extratos Solanum lycocarpum St. -Hil (Solanaceae) no ciclo celular de Lactuca sativa e Allium cepa

Solanum lycocarpum St.- Hil popularly known as 'fruta-de-lobo' or 'lobeira' is native to the Brazilian Cerrado, and used in folk medicine due to its phytotherapic properties. The action of S. lycocarpum on the cell cycle and chromosomes in order to demonstrate whether there are aneugenic and/or clastogenic effects is unknown. Thus, this study aimed at investigating the cytotoxic and genotoxic potential of methanol and hexane extracts of S. lycocarpum on growth and cell cycle of Lactuca sativa and Allium cepa. Roots from both species were exposed for 72 hours to methanol and hexane extracts with 50, 100, and 200 µg mL-1 of S. lycocarpum. Slides were prepared by the squash technique and then analyzed to determine the mitotic index and the total of chromosomal and nuclear abnormalities. The frequencies of chromosomal and nuclear abnormalities were high and significant with a dose-dependent effect, indicating that S. lycocarpum has a cytotoxic and genotoxic action depending on the dose used on meristem cells of A. cepa and L. sativa.

Solanum lycocarpum St.-Hil (Solanaceae) conhecida popularmente como fruta-de-lobo ou lobeira é uma planta nativa do Cerrado brasileiro, utilizada na medicina popular nos tratamentos de diabetes, obesidade e redução do colesterol. Ainda não é conhecida a ação de S. lycocarpum sobre o ciclo celular e os cromossomos, demonstrando se possuem efeitos aneugênicos e/ou clastogênicos. O objetivo desse estudo foi investigar o potencial citotóxico e genotóxico dos extratos metanólico e hexânico de S. lycocarpum sob o crescimento e ciclo celular de Lactuca sativa e Allium cepa. As raízes de ambas as espécies foram expostas por 72h aos extratos metanólico e hexânico com 50, 100 e 200 µg mL-1 de S. lycocarpum. As lâminas foram montadas pela técnica de esmagamento e em seguida foram analisadas, afim de determinar o índice mitótico e anormalidades cromossômicas e nucleares. As frequências de anormalidades cromossômicas e nucleares foram altas e significativas, com efeito dose-dependente e confirmando que S. lycocarpum tem ação citotóxica e genotóxica de acordo com a dose utilizada sobre as células meristemáticas de A. cepa e L. sativa.

The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives

Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.

In vitro antifungal activity of fatty acid methyl esters of the seeds of Annona cornifolia A.St.-Hil. (Annonaceae) against pathogenic fungus Paracoccidioides brasiliensis / Atividade antifúngica in vitro dos ésteres metílicos de ácidos graxos das sementes de Annona cornifolia A.St.-Hil. (Annonaceae) sobre o fungo patogênico Paracoccidioides brasiliensis

INTRODUCTION: Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. METHODS: Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. RESULTS: In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. CONCLUSIONS: FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.

INTRODUÇÃO: Os ácidos graxos são abundantes em óleos vegetais. Eles são conhecidos por suas propriedades antibacterianas e antifúngicas. MÉTODOS: A suscetibilidade a antifúngicos foi avaliada pelo ensaio de microdiluição em caldo de acordo com CLSI (anteriormente NCCLS) sobre 16 isolados de interesse clínico. RESULTADOS: Nesse trabalho, os ésteres metílicos de ácidos graxos (FAME) inibiram doze isolados clínicos do fungo patogênico Paracoccidioides brasiliensis, e também foi muito ativo no ensaio de bioautografia sobre o fungo Cladosporium sphaerospermum. CONCLUSÕES: FAME foi um antifúngico mais potente do que sulfametoxazol-trimetoprim contra P. brasiliensis, nas condições utilizadas no presente trabalho.