RESUMO
AIM: To evaluate the antibacterial activity of 12 kaurane-type diterpenes against a panel of bacteria that cause endodontic infection. METHODS & MATERIALS: We conducted tests against bacteria in the planktonic or in the sessile mode, cytotoxic assays for the most promising compounds against human normal lung fibroblast cells, and Porphyromonas gingivalis (ATCC 33277) proteomic analysis. RESULTS & CONCLUSION: Kaurenoic acid and its salt exhibited satisfactory antibacterial action against the evaluated bacteria. Proteomic analysis suggested that these compounds might interfere in bacterial metabolism and virulence factor expression. Kaurane-type diterpenes are an important class of natural products and should be considered in the search for new irrigating solutions to treat endodontic infections.
Assuntos
Antibacterianos/farmacologia , Infecções por Bacteroidaceae/tratamento farmacológico , Diterpenos/farmacologia , Porphyromonas gingivalis/efeitos dos fármacos , Antibacterianos/química , Infecções por Bacteroidaceae/microbiologia , Biofilmes/efeitos dos fármacos , Diterpenos/química , Humanos , Viabilidade Microbiana/efeitos dos fármacos , Mikania/química , Extratos Vegetais/química , Folhas de Planta/química , Porphyromonas gingivalis/crescimento & desenvolvimento , Porphyromonas gingivalis/isolamento & purificação , Pulpite/tratamento farmacológico , Pulpite/microbiologiaRESUMO
OBJECTIVES: This work aimed to evaluate the antifungal and cytotoxic activity of the EtOH extract and fractions of Banisteriopsis argyrophylla leaves, and to perform the identification of these bioactive metabolites. METHODS: The EtOAc fraction (EAF) obtained from the ethanolic extract of B. argyrophylla leaves showed better antifungal potential against Candida spp. In this fraction, ten flavonoids have been identified by UHPLC-ESI-MSn . Then, EAF was submitted to column chromatography to give four new fractions (A1-A4). The cytotoxicity was determined against Vero cells. KEY FINDINGS: The EAF showed better antifungal potential against Candida spp. with minimum inhibitory concentrations (MICs) between 31.25 and 93.75 µg/ml. The (-)-catechin (fraction A1) showed a MIC of 2.83 µg/ml against Candida glabrata. Fractions A2, A3 and A4 were rich in quercetins and kaempferols and showed good inhibitory concentrations (5.86-46.87 µg/ml) against C. albicans, C. glabrata and C. tropicalis. CONCLUSIONS: The EtOH extract, fractions and the isolated (-)-catechin showed lower toxicity to Vero cells than cisplatin, used as a positive control. Thus, the leaves of B. argyrophylla are a promising source of antifungal agents.
Assuntos
Antifúngicos/farmacologia , Banisteriopsis , Candida/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta , Animais , Antifúngicos/isolamento & purificação , Antifúngicos/toxicidade , Banisteriopsis/química , Candida/classificação , Candida/crescimento & desenvolvimento , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Folhas de Planta/química , Células VeroRESUMO
We evaluated the antibacterial activity of three diterpenes isolated from natural sources against a panel of microorganisms responsible for bovine mastitis. ent-Copalic acid (CA) was the most active metabolite, with promising MIC values (from 1.56 to 6.25 µg mL-1) against Staphylococcus aureus (ATCC and clinical isolate), Staphylococcus epidermidis, Streptococcus agalactiae, and Streptococcus dysgalactiae. We conducted time-kill assays of CA against S. aureus, a commensal organism considered to be a ubiquitous etiological agent of bovine mastitis in dairy farms worldwide. In the first 12 h, CA only inhibited the growth of the inoculums (bacteriostatic effect), but its bactericidal effect was clearly noted thereafter (between 12 and 24 h). In conclusion, CA should be considered for the control of several Gram-positive bacteria related to bovine mastitis.
