Biological activity of selected lichens and lichen-based Ag nanoparticles prepared by a green solid-state mechanochemical approach
| Autor: | Martin Bačkor, Michal Goga, Ján Elečko, Nina Daneu, Matej Baláž, Margaréta Marcinčinová, Ľudmila Tkáčiková |
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| Rok vydání: | 2020 |
| Předmět: |
Pseudevernia furfuracea
Antioxidant Materials science Silver Lichens medicine.medical_treatment Metal Nanoparticles Bioengineering 02 engineering and technology Microbial Sensitivity Tests 010402 general chemistry 01 natural sciences Silver nanoparticle Antioxidants Biomaterials chemistry.chemical_compound Ascomycota medicine Food science Phenols Lobaria pulmonaria biology Plant Extracts Parmeliaceae Biological activity Green Chemistry Technology 021001 nanoscience & nanotechnology biology.organism_classification 0104 chemical sciences Anti-Bacterial Agents Silver nitrate chemistry Mechanics of Materials 0210 nano-technology Antibacterial activity |
| Zdroj: | Materials scienceengineering. C, Materials for biological applications. 119 |
| ISSN: | 1873-0191 |
| Popis: | Lichens dispose a wide spectrum of bioactive compounds known as secondary metabolites. Their biological effects like antioxidant and antibacterial activities are widely studied. Green synthesis of silver nanoparticles (AgNPs) is a method where the compounds/substances present in plants are used for reduction of AgNO3instead of toxic chemicals. However, this methodology is usually a two-step process (extract preparation step and the synthesis step) performed under the elevated temperatures nad in the case of lichens, the redicing compounds are insoluble in water. These disadvantages can be overcome by a solid-state mechanochemical synthesis applied in the present study. As microorganisms are becoming more resistant to commercial antibiotics, AgNPs prepared in an environmentally friendly way represent an interesting alternative. In the present study, we compared the processing of lichen material of Pseudevernia furfuracea and Lobaria pulmonaria for extraction as well as for synthesis of AgNPs, and tested the antibacterial and antioxidant activity of the extracts. Both selected lichen species could be successfully used as reducing agents to produce AgNPs. Six different bacterial strains were tested for antibacterial activity of AgNPs-containing products and it was highly effective on all strains. However, the antioxidant activity of lichen extracts showed the lowest effect even if AgNPs are present which positively correlated with the content of total phenols and flavonoids. Both phenols and flavonoids are natural antioxidants and react with silver nitrate. Due to this fact, we observed a decrease of total phenols, total flavonoids as well as antioxidant activity when processing of lichen extracts with silver nitrate was used. We demonstrated that the formation of AgNPs increased the antibacterial activity but on the other hand reduced the antioxidant activity. Thus, antibacterial and antioxidant effects have to be treated differentially. |
| Databáze: | OpenAIRE |
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