Marijana Kosanić

Evernia prunastri and Pseudoevernia furfuraceae lichens and their major metabolites as antioxidant, antimicrobial and anticancer agents

The aim of this study is to investigate chemical composition of acetone extracts of the lichens Evernia prunastri and Pseudoevernia furfuraceae and in vitro antioxidant, antimicrobial, and anticancer activities of these extracts and some their major metabolites. HPLC-UV method was used for identification of secondary metabolites. Antioxidant activity was evaluated by free radical scavenging, superoxide anion radical scavenging, reducing power and determination of total phenolic compounds. As a result of the study physodic acid had largest antioxidant activities. Total content of phenol in extracts was determined as pyrocatechol equivalent. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was also physodic acid. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method.

Chemical composition of three Parmelia lichens and antioxidant, antimicrobial and cytotoxic activities of some their major metabolites.

The aim of this study is to investigate chemical composition of acetone extracts of the lichens Parmelia caperata, P. saxatilis and P. sulcata and antioxidant, antimicrobial and anticancer activities of some their major metabolites. The phytochemical analysis of acetone extracts of three Parmelia lichens were determined by HPLC-UV method. The predominant phenolic compounds in these extracts were protocetraric and usnic acids (P. caperata) and depsidone salazinic acid (other two species). Besides these compounds, atranorin and chloroatranorin, were also detected in some of these extracts. Antioxidant activity of their isolated metabolites was evaluated by free radical scavenging, superoxide anion radical scavenging and reducing power. As a result of the study salazinic acid had stronger antioxidant activity than protocetraric acid. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. Both compounds were highly active with minimum inhibitory concentration values ranging from 0.015 to 1mg/ml. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. Salazinic acid and protocetraric acid were found to be strong anticancer activity toward both cell lines with IC(50) values ranging from 35.67 to 60.18μg/ml. The present study shows that tested lichen compounds demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggest that these lichens can be used as new sources of the natural antimicrobial agents, antioxidants and anticancer compounds.

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

BackgroundThe aim of this study is to investigate in vitro antioxidant, antimicrobial and anticancer activity of the acetone extracts of the lichens Cladonia furcata, Lecanora atra and Lecanora muralis.MethodsAntioxidant 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.ResultsOf the lichens tested, Lecanora atra 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 Cladonia furcata 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 IC50 values ranging from 8.51 to 40.22 μg/mL.ConclusionsThe 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.

Antioxidant properties of some lichen species

Antioxidant activity of the acetone, methanol and aqueous extracts of the lichens Cladonia furcata, Hypogymnia physodes, Lasallia pustulata, Parmelia caperata and Parmelia sulcata has been screened in vitro by using different methods (DPPH radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds and determination of total flavonoid content). Of the lichens tested, Lasallia pustulata had powerful antioxidant activities. Acetone, methanol and aqueous extracts of this lichen showed 90.93, 69.87 and 65.08% DPPH radical scavenging activities. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. Those various antioxidant activities were compared to standard antioxidants such as ascorbic acid, butylated hydroxyanisole (BHA) and α-tocopherol. In addition, total content of phenol and flavonoid in extracts were determined as pyrocatechol equivalent, and as rutin equivalent, respectively. The strong relationships between total phenolic and flavonoid contents and the antioxidative activities of tested extracts suggest that these compounds play important role in antioxidant activity. The present stady shows that tested lichen species demonstrated a strong antioxidant activity and can be considered as good sources of natural antioxidants.

Antioxidant, antimicrobial and anticancer activities of three Parmelia species

BACKGROUND Lichens are symbiotic organisms consisting of algae and fungi. They are used for human and animal nutrition and in the production of colours, perfumes and alcohol. Lichens have also been used in traditional medicine to treat diseases such as jaundice, pulmonary, stomach and cranial diseases. In this study the acetone extracts of three lichens, Parmelia caperata, Parmelia sulcata and Parmelia saxatilis, were tested for their antioxidant, antimicrobial and anticancer potential. RESULTS Of the lichens tested, P. saxatilis had the highest free radical-scavenging activity (55.3% inhibition). Moreover, all tested extracts showed effective reducing power and superoxide anion radical scavenging. Strong relationships between total phenolic and flavonoid contents and antioxidant effects of the tested extracts were observed. The extract of P. sulcata was most active in terms of antimicrobial ability, with minimum inhibitory concentration values ranging from 0.78 to 12.5 mg L⁻¹. All extracts were found to have strong anticancer activity, with IC₅₀ values ranging from 9.55 to 22.95 µg mL⁻¹. CONCLUSION The present study showed that the tested lichen extracts exhibited strong antioxidant, antimicrobial and anticancer effects. This suggests that lichens may be used as possible natural antioxidant, antimicrobial and anticancer agents.

Antioxidant, Antimicrobial, and Anticancer Activity of 3 Umbilicaria Species

The aim of this study is to investigate in vitro antioxidant, antimicrobial, and anticancer activity of the acetone extracts of the lichens Umbilicaria crustulosa, U. cylindrica, and U. polyphylla. Antioxidant activity was evaluated by 5 separate methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds, and determination of total flavonoid content. Of the lichens tested, U. polyphylla had largest free radical scavenging activity (72.79% inhibition at a concentration of 1 mg/mL), which was similar as standard antioxidants in the same concentration. Moreover, the tested extracts had effective reducing power and superoxide anion radical scavenging. Total content of phenol and flavonoid in extracts was determined as pyrocatechol equivalent, and as rutin equivalent, respectively. The strong relationships between total phenolic and flavonoid contents and the antioxidant effect of tested extracts were observed. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method. The most active was extract of U. polyphylla with minimum inhibitory concentration values ranging from 1.56 to 12.5 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using MTT method. All extracts were found to be strong anticancer activity toward both cell lines with IC₅₀ values ranging from 28.45 to 97.82 μg/mL. The present study shows that tested lichen extracts demonstrated a strong antioxidant, antimicrobial, and anticancer effects. That suggests that lichens may be used as possible natural antioxidant, antimicrobial, and anticancer agents.

Biological Activities of Toninia candida and Usnea barbata Together with Their Norstictic Acid and Usnic Acid Constituents

The aim of this study was to investigate the chemical composition of acetone extracts of the lichens Toninia candida and Usnea barbata and in vitro antioxidant, antimicrobial, and anticancer activities of these extracts together with some of their major metabolites. The chemical composition of T. candida and U. barbata extracts was determined using HPLC-UV analysis. The major phenolic compounds in these extracts were norstictic acid (T. candida) and usnic acid (U. barbata). Antioxidant activity was evaluated by free radical scavenging, superoxide anion radical scavenging, reducing power and determination of total phenolic compounds. Results of the study proved that norstictic acid had the largest antioxidant activity. The total content of phenols in the extracts was determined as the pyrocatechol equivalent. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration using the broth microdilution method. The most active was usnic acid with minimum inhibitory concentration values ranging from 0.0008 to 0.5 mg/mL. Anticancer activity was tested against FemX (human melanoma) and LS174 (human colon carcinoma) cell lines using the microculture tetrazolium test. Usnic acid was found to have the strongest anticancer activity towards both cell lines with IC50 values of 12.72 and 15.66 μg/mL.

Antioxidant and antimicrobial properties of the lichens Anaptychya ciliaris, Nephroma parile, Ochrolechia tartarea and Parmelia centrifuga

The aim of this study was to characterize the antioxidant and antimicrobial activity of the methanol extracts of: Anaptychya ciliaris, Nephroma parile, Ochrolechia tartarea and Parmelia centrifuga. The methanol extract of the P. centrifuga showed a strong antioxidant activity, in comparison to the extracts from A. ciliaris, O. tartarea and N. parile which were relatively weaker. Furthermore, the methanol extract of the lichen P. centrifuga was shown to contain the highest total phenol content (54.19 mg/g of the dry extract). Interestingly, a statistically significant positive relationship between the antioxidant activity and the total phenol content was observed. The minimum inhibitory concentration (MIC) against six bacterial and eleven fungi was established for the methanol extracts from each of species of lichens. The methanol extracts of the lichens P. centrifuga and O. tartarea showed the strongest both antibacterial and antifungal activity. Taken together, the results from this study suggest that the lichens P. centrifuga and O. tartarea may be used as a natural source of antioxidants in addition to providing certain antimicrobial features.

Antioxidant and Antimicrobial Properties of Some Lichens and Their Constituents

The aim of this study is to examine the in vitro antioxidant and antimicrobial activities of the acetone, methanol, and aqueous extracts of the lichens Cladonia furcata (many-forked Cladonia), Hypogymnia physodes (puffed lichen), and Umbilicaria polyphylla (manyleaf navel lichen) and the antimicrobial activity of fumarprotocetraric acid, gyrophoric acid, and physodic acid isolated from the respective lichen species. Antioxidant activity was evaluated by five different methods: free radical scavenging, superoxide anion radical scavenging, reducing power, determination of total phenolic compounds, and determination of total flavonoid content. U. polyphyla exhibited more powerful antioxidant activities than the other lichen species examined: methanol extracts of U. polyphyla showed 90.08% free radical scavenging activities (the ratio was greater than those of standard antioxidants). Moreover, the extracts tested had effective reducing power and superoxide anion radical scavenging. Total contents of phenol and flavonoid in extracts were determined as pyrocatechol equivalents and as rutin equivalents, respectively. A significant strong relationship between total phenolic and flavonoid contents and their antioxidative activities was observed. The antimicrobial activity was estimated by determination of the minimal inhibitory concentration by the broth microdilution method against six species of bacteria and 10 species of fungi. In general, the lichen extracts tested and their respective acids had relatively strong antimicrobial activity against the microorganisms tested. The present study shows that the lichen species tested demonstrated strong antioxidant and antimicrobial activities. The results suggest that lichens may be used as good sources of natural antioxidants and for pharmaceutical purposes in treating various diseases.

Biological activities of two macroalgae from Adriatic coast of Montenegro

In the present investigation the acetone extracts of macroalgae Ulva lactuca and Enteromorpha intestinalis were tested for antioxidant, antimicrobial and cytotoxic potential. Antioxidant activity was evaluated by measuring the scavenging capacity of tested samples on DPPH and superoxide anion radicals, reducing the power of samples and determination of total phenolic and flavonoid compounds in extracts. As a result of the study, U. lactuca extract was found to have a better free radical scavenging activity (IC50 = 623.58 μg/ml) than E. intestinalis extract (IC50 = 732.12 μg/ml). Moreover, the tested extracts had effective ferric reducing power and superoxide anion radical scavenging. The total content of phenol in extracts of U. lactuca and E. intestinalis was 58.15 and 40.68 μg PE/mg, while concentrations of flavonoids were 39.58 and 21.74 μg RE/mg, respectively. Furthermore, among the tested species, extracts of U. lactuca showed a better antimicrobial activity with minimum inhibitory concentration values ranging from 0.156 to 5 mg/ml, but it was relatively weak in comparison with standard antibiotics. Bacillus mycoides and Bacillus subtilis were the most susceptible to the tested extracts. Contrary to this Aspergillus flavus, Aspergillus fumigatus and Penicillium purpurescens were the most resistant. Finally, cytotoxic activity of tested extracts was evaluated on four human cancer cell lines. Extract of E. intestinalis expressed the stronger cytotoxic activity towards all tested cell lines with IC50 values ranging from 74.73 to 155.39 μg/ml.