Antioxidant, antimicrobial and anticancer activity of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis

<p>Abstract</p> <p>Background</p> <p>The aim of this study is to investigate in vitro antioxidant, antimicrobial and anticancer activity of the acetone extracts of the lichens <it>Cladonia furcata, Lecanora atra </it>and <it>Lecanora muralis</it>.</p> <p>Methods</p> <p>Antioxidant activity was evaluated by five separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds and determination of total flavonoid content. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method against six species of bacteria and ten species of fungi. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method.</p> <p>Results</p> <p>Of the lichens tested, <it>Lecanora atra </it>had largest free radical scavenging activity (94.7% inhibition), which was greater than the standard antioxidants. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. Extract of <it>Cladonia furcata </it>was the most active antimicrobial agent with minimum inhibitory concentration values ranging from 0.78 to 25 mg/mL. All extracts were found to be strong anticancer activity toward both cell lines with IC₅₀values ranging from 8.51 to 40.22 μg/mL.</p> <p>Conclusions</p> <p>The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial and anticancer effects. That suggest that lichens may be used as as possible natural antioxidant, antimicrobial and anticancer agents to control various human, animal and plant diseases.</p

Lichens as biological indicators of air quality in the urban area of Kuršumlija (Southern Serbia)

In this work, we provided a first indication of Kuršumlija (town of Southern Serbia) air quality using epiphytic lichens known as bioindicators. The investigations were carried out from April to October 2014. The analysis of thalli samples (from 15 investigated points in Kuršumlija), indicates the presence of 42 lichens taxa from 23 genera. An assessment of air quality was made by using the Index of Atmospheric Purity (IAP) and Index of Human Impact (IHI). IHI values ranged between 15 and 36. IAP values ranged between 10 and 28. According to the IAP values, it has been found that there are three different air pollution zones: “normal”, “struggle” and “lichen desert”. The latest characterize the majority of the urban area. The aim of this study is to formulate an indication of air quality using lichens as bioindicators on the basis of lichens diversity and frequency. This is of great importance because there are no continuous physical and chemical measurements of air quality in this area