Produção de metabólitos bioativos pelo líquen Cladonia substellata Vainio

Abstract

RESUMO -(Produção de metabólitos bioativos pelo líquen Cladonia substellata Vainio). Objetivando comparar a atividade antimicrobiana de extratos brutos de Cladonia substellata, proveniente dos Estados de Minas Gerais e Pará, Brasil, utilizou-se o método de difusão em meio sólido. Extratos etéreo, clorofórmico e acetônico foram testados contra patógenos humanos e fitopatógenos na concentração de 1,0 mg/mL, 0,1 mg/mL e 0,01 mg/mL. Os extratos foram submetidos à cromatografia em camada delgada, e o princípio ativo atribuído através de biocromatografia. Os resultados demonstraram que as sete espécies de fungos testadas foram resistentes aos extratos de C. substellata procedente do Pará, porém, quatro destas espécies mostraram-se sensíveis aos extratos etéreo e clorofórmico da amostra de Minas Gerais. Todos os extratos foram ativos contra as mesmas espécies de bactérias, entretanto os extratos da amostra procedente de Minas Gerais demonstraram melhor atividade. Das bactérias inibidas, Staphylococcus aureus mostrou-se a menos sensível, ao contrário das fitopatógenas que apresentaram grande sensibilidade. Os testes cromatográficos revelaram a presença de ácido úsnico em todos os extratos, porém, em maior quantidade na amostra do Pará. O biocromatograma revelou este ácido como princípio ativo da espécie, além de sua ação sinérgica com o ácido norestíctico, na amostra de Minas Gerais, justificando sua maior atividade. Palavras-chave:Cladonia substellata, ácido úsnico, ácido norestíctico, atividade antimicrobiana ABSTRACT -(Production of bioactive metabolites from lichen Cladonia substellata Vainio). This work purposed to make a comparison between antimicrobial activity of crude extracts from Cladonia substellata, collected at Minas Gerais and Pará States, Brazil, using the diffusion solid medium methods. Ether, chloroform, and acetone extracts, at 1 mg/mL, 0.1 mg/mL, and 0.01 mg/mL, were tested against human pathogens and phytopathogens. The extracts were submitted to thin layer chromatography and their active principles attributed by biochromatography. The results demonstrated that the seven fungi species tested were no sensitive to extracts from C. substellata from Pará. On the other hand, four of these microorganisms were inhibited by C. substellata extracts from Minas Gerais. All extracts were active to the same bacteria species, but samples from Minas Gerais showed the highest activity. Among the inhibited bacteria Staphylococcus aureus was the less sensitive, with an opposite behavior to phytopathogen ones, that showed the highest sensitivity. Chromatographic assays revealed the presence of usnic acid in all extracts, thus in the most content in Pará samples. The biochromatograms reveals usnic acid as active principle of the species, and a synergic action to norstictic acid found in Minas Gerais samples, what justify its highest activity.

In vitro antimicrobial activity of the organic extract of Cladonia substellata Vainio and usnic acid against Staphylococcus spp. obtained from cats and dogs

“…This can be explained by the composition of the organic extract of C. substellata originating from the Northeast of Brazil, with approximately 98% usnic acid in its composition (Huovinen & Ahti 1986, Ahti et al 1993, Yano-Melo et al 1999). This may be primarily responsible for the antimicrobial activity demonstrated in this study and others (Burkholder et al 1944, Carrazzoni 1975, Huovinen & Ahti 1986, Ahti et al 1993, Lauterwein et al 1995, Pereira et al 1997, Honda & Vilegas 1998, Yano-Melo et al 1999, Donlan 2001, Falcão et al 2004, Ribeiro et al 2006, Moura et al 2008. Ranković et al (2012) tested the antibacterial activity of usnic acid compared to streptomycin for Bacillus mycoides (ATCC 6462), B. subtilis (ATCC 6633), S. aureus (ATCC 25923), Escherichia coli (ATCC 25922), and Klebsiella pneumoniae (ATCC 13883).…”

“…It also acts as an insecticide, moisturizer, antihistamine, and agent that offers protection from the harmful effects of lightning UV (Fournet et al 1997, Cochietto et al 2002, Ingólfsdóttir 2002, Falcão et al 2004, Ribeiro et al 2006, Honda et al 2010. In humans, a hepatotoxic effect was observed when it was used systemically (Moura et al 2008).…”

In vitro analysis of antibacterial and antifungal potential of lichen species of Everniastrum cf vexans, Parmotrema blanquetianum, Parmotrema reticulatum and Peltigera laciniata

“…The standard chloramphenicol presented activity in almost all bacterial strains tested, except Listeria monocytogenes and Escherichia coli, being the persistent results in the three techniques use Previous research had reported antibacterial activity in several lichen species against Gram-positive and Gram negative bacterias in a wide variety of concentrations, under some technique used. [24][25][26][27] Some authors indicate that the vast majority of lichens are more active against Gram-positive than Gram-negative bacteria. 5,23 The difference in sensitivity between bacterias can be attributed to the different composition of the cell walls that exists between these microorganisms (varying permeability), which in some cases blocks the entry of certain compounds into the cellular interior.…”

Production of Bioactive Lichen Compounds by Alginate-Immobilized Bionts Isolated from Cladonia verticillaris: An in Vitro Study

“…Lichen extracts are mixtures of different compounds, and their antimicrobial activity is not only the result of the different activities of individual components but may be the result of their interactions, which can have different effects on the overall activity of extracts. Ribeiro et al (2006) also reported action of ether extract from C. substellata against human and plant pathogenic bacteria and supposed a synergic action between their components. Martins et al (2010) also showed a synergic action of organic extract of C. aggregata against S. aureus.…”