Growth inhibition and antioxidative response of wood decay fungi exposed to plant extracts ofCaseariaspecies

Abstract

Significance and Impact of the Study: The Casearia plant extracts exhibited important antifungal activity on wood decay fungi and triggered oxidative stress process, an inhibitory mechanism rarely studied in filamentous fungi exposed to plant extracts. Therefore, a starting point was provided for the development of natural compounds-based products as an alternative to chemical fungicides. In addition, subsidies were given to further studies in order to elucidate in more detail how compounds present in extracts of native tropical plants affect the physiology of fungi. AbstractLigninolytic fungi take part in critical processes in ecosystems such as nutrient recycling; however, some fungal species can be pathogenic to forest and urban trees and deteriorate wood products. The tropical flora is an important source of antimicrobial compounds environmentally safer than traditional wood preservatives. Therefore, this study aimed to evaluate the inhibitory activity of ethanol plant extracts of Casearia sylvestris and Casearia decandra on the white-rot wood decay basidiomycetes Trametes villosa and Pycnoporus sanguineus. In addition, the effect of the extracts on the fungal antioxidative metabolism was studied. Among the different substances present in the extracts, the phytochemical analyses identified a clerodane diterpenoid (C. sylvestris) and cinnamic acid, hydroquinone and b-sitosterol (C. decandra). The extracts inhibited the fungi up to 70% and caused hyphal morphology changes. The extracts triggered oxidative stress process as indicated by the increased levels of the antioxidant enzymes catalase and glutathione reductase. Therefore, the Casearia extracts are a potential source of natural biocides to control wood decay fungi, and one of the mechanisms of action is the oxidative stress.

Terrestrial orchids in a tropical forest: best sites for abundance differ from those for reproduction

“…Our knowledge of tropical orchid-fungi relationships is limited, but the indicator species analysis results may provide useful insights on direct and indirect species interactions, suitable habitat niches, or edaphic condi- tions that promote orchid germination or population establishment. The roots, or decomposing organic matter, associated with positive indicator species may help to facilitate mycorrhizal networks (Gowland et al 2011, McCormick et al 2012, Bunch et al 2013, whereas negative indicator species may host pathogens or may excrete secondary compounds that inhibit the fungi upon which orchids rely (Bento et al 2014). Within our study site, the mycoheterotrophic orchid Wullschlaegelia calcarata is associated with nearly three dozen indicator species (Bergman et al 2006), whereas P. stachyodes has fewer significant associations (or potentially more specialized relationships).…”

“…and negative with Casearia sylvestris (Rich.) Urb., a species with anti-fungal properties (Bento et al 2014)). …”

Toxicity of plant extracts from Bahia, Brazil, to Atta sexdens sexdens workers (Hymenoptera: Formicidae)

“…The toxicity of C. sylvestris extracts to leaf cutting ants may be due to its diterpenes, class of substances compounds with biological activities, including antifungal effect (Bento et al, 2013). The alkaloids (Januário et al, 2009) and coumarins from E. grandiflora were toxic to Aedes aegypti larvae (Oliveira et al, 2005).…”

“…Simarouba versicolor was toxic to cutting-ants at concentrations of 2.0, 1.6 and 0.3 mg.mL 1 (Peñaflor et al, 2009). Species of Casearia genus present therapeutic properties and active substances as diterpenes, called casearins (Bento et al, 2013). Aspidosperma has species, including A. spruceanum, important sources of indole alkaloids with therapeutic properties (Oliveira et al, 2009).…”

The Future Use of Medicinal Plants as Alternatives to Antibiotics in Animal Health and Production

“…A clear effectiveness of low doses of essential oils and sodium butyrate were reported against Salmonella in broilers [14]. The blend of thymol and cinnamaldehyde is proven to have selective antibacterial properties inhibiting the growth of yeast and fungi [15]. However, Most supplements claimed to be alternatives to antibiotics have effects on the microflora, either directly or indirectly [16].…”