RESUMO
The increase in antibiotic resistance due to multiple factors has encouraged the search for new compounds which are active against multidrug-resistant pathogens. In this context, chalcones, dihydrochalcones, hydrazones and oxadiazoles were tested against Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus (MRSA) isolates, which were obtained from clinical laboratories and were characterized as MRSA using traditional and molecular methods. Among 65 tested compounds, two chalcones, one dihydrochalcone and two hydrazones were active against MRSA. Based on the minimal inhibitory concentration and cytotoxicity, hydrazones provided a better selectivity index than chalcones. Active hydrazones are promising antibiotic-like substances and they should be the subject of further microbiological studies.
Assuntos
Antibacterianos/farmacologia , Chalconas/farmacologia , Hidrazonas/farmacologia , Staphylococcus aureus Resistente à Meticilina/metabolismo , Meticilina/farmacologia , Oxidiazóis/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/metabolismo , Animais , Chalconas/química , Chlorocebus aethiops , Humanos , Hidrazonas/química , Testes de Sensibilidade Microbiana , Modelos Químicos , Infecções Estafilocócicas/microbiologia , Células VeroRESUMO
We developed reproducible protocols for micropropagation, callus culture, and root culture of the medicinal plant Phyllanthus urinaria, P. niruri, P. tenellus, P. corcovadensis, P. caroliniensis, P. stipulatus, and P. fraternus by using single node explants. Genotype-linked differences are visible among the Phyllanthus species concerning shoot culture, callus culture, and root culture growth. The protocols developed for phytochemical screening of callus and root extracts of P. urinaria, P. caroliniensis, P. stipulatus, and P. fraternus have shown the production of sterols and triterpenes. Both compounds are known to account for the antinociceptive activity of the methanolic extracts as glochidone and stigmasterol have strong activity against neurogenic and inflammatory pain. Similarly, methanolic callus extracts of P. tenellus, P. niruri and P. corcovadensis have potent analgesic properties, however phenolics are major compounds isolated from these species. The optimized micropropagation, callus culture, and root culture protocols offer the possibility to use cell/root culture techniques for vegetative propagation and secondary metabolite studies.
Assuntos
Phyllanthus/química , Phyllanthus/crescimento & desenvolvimento , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Phyllanthus/classificação , Especificidade da Espécie , Técnicas de Cultura de TecidosRESUMO
A wide variety of noxious stimuli are known to induce a sensation of pain evoked in a remote region of the body. Here, we show that chalcones can inhibit the pain provoked by the administration of an intraperitoneal acetic acid (AA). This study investigates the effects of 17 synthetic chalcones in the writhing test, a visceral pain model in mice. The majority of these compounds proved more active than some analgesic drugs, such as aspirin and acetaminophen, two reference drugs used here for comparison. Four chalcones, 9, 10, 16, and 17, were selected for more detailed studies, since they exhibited significant antinociceptive activities and chemical structures of interest. They caused dose-related inhibitions, proving about 15-, 10-, 9-, and 8-fold more active than the standard drugs. When administrated orally, only chalcone 9 proved to be effective. These chalcones might be further used as a model to obtain new and more potent analgesic drugs.