Antibacterial and cytotoxic properties of some plant crude extracts used in Northeastern folk medicine

Abstract

RESUMO: "Propriedades antibacterianas e citotóxicas de alguns extratos de plantas usados na medicina popular nordestina". No presente estudo, 32 extratos hexânicos e etanólicos de Protium bahianum, P. heptaphyllum, Croton sellowii, C. rhamnifolius, C. jacobinensis, C. micans e Muntingia calabura, foram avaliados para atividade antibacteriana, pelo método de difusão em disco. Ensaios de citoxicidade foram realizados com o modelo do microcrustáceo Artemia salina Leach para determinar a concentração letal para 50% dos indivíduos (CL 50 µg/mL). A presença de atividade antibacteriana foi observada com os extratos hexânicos das flores de M. calabura contra B. subtilis, e extratos etanólicos das folhas contra S. aureus and B. subtilis na concentração de 1 mg/mL. Dentre os 32 extratos, 19 apresentaram toxicidade baixa ou ausente (CL 50 > 250 µg/mL), 6 mostraram toxicidade moderada (CL 50 entre 80 µg/mL e 250 µg/mL) e 7 foram muito tóxicos (CL 50 < 80 µg/mL). Unitermos:Artemia salina, citotoxicidade, atividade antibacteriana, Croton, Protium, Muntingia calabura. ABSTRACT:In the present study, 32 hexane and ethanol extracts of Protium bahianum, P. heptaphyllum, Croton sellowii, C. rhamnifolius, C. jacobinensis, C. micans and Muntingia calabura were screened for antibacterial activity by the disc-diffusion method. Cytotoxicity assays using the brine shrimp Artemia salina Leach as a model were performed to determine lethal doses for 50% of individuals (LC 50 µg/mL). Antibacterial activity was found in flowers hexane extracts of M. calabura against B. subtilis, and leaves ethanol extracts against S. aureus and B. subtilis at concentration of 1mg/mL. Among 32 extracts, 19 showed low or no toxicity (LC 50 > 250 µg/mL), 6 showed moderate toxicity (LC 50 between 80 µg/mL and 250µg/mL), and 7 were highly toxic (LC 50 < 80 µg/mL).

Chemical Constituents and Biological Activities of Croton heliotropiifolius Kunth

“…These authors observed both leishmanicidal and trypanocidal effects, but with high cytotoxicity against fibroblasts. On the other hand, Ramos et al [ 75 ] demonstrated that hexane extracts obtained from both the leaves and stem of this plant showed moderate cytotoxicity. In this study, we demonstrated that the root extract does not have significant antiparasitic effects.…”

Solvent extracts of the red seaweed Gracilaria fisheri prevent Vibrio harveyi infections in the black tiger shrimp Penaeus monodon

“…With respect to toxicity of the ethanol extract, substances are considered strongly toxic when their LC 50 for Artemia instar I larvae are in the range of 0e80 mg ml À1 , moderately toxic at 80e250 mg ml À1 , and weakly toxic at more than 250 mg ml À1 [30]. Since the LC 50 of our ethanol extract was 4290 AE 460 mg ml À1 , it could be considered non-toxic to the Artemia instar I larvae.…”

Phytochemical Screening and Evaluation of the Toxicity of Croton heliotropiifolius Kunth (Euphorbiacea) on Artemia salina Leach

“…Segundo Ramos et al (2009) 15 16 Os representantes do gênero Croton costumam apresentar-se como ervas ou arbustos, que são utilizadas simplesmente como bebidas na forma de chás, sendo reconhecidos tanto por suas propriedades medicinais, quanto tóxicas. As espécies que compõe esse gênero são geralmente odoríferas e contém um látex cáustico que é responsável por causar dermatite e que pode ser venenoso.…”