Phytochemical study and antioxidant, antimicrobial and anticancer activities of Melanelia subaurifera and Melanelia fuliginosa lichens

Abstract

The aim of this study was to investigate antioxidant, antimicrobial and anticancerous activity of Melanelia subaurifera and Melanelia fuliginosa. The phytochemical analysis was determined by HPLC-UV method. Antioxidant activity was evaluated by DPPH and reducing power assay while antimicrobial activity was determined by minimal inhibitory concentration. The cytotoxic activity was tested using MTT method. The method for quantification of 2'-O-methyl anziaic acid and lecanoric acid in these lichens using RF-HPLC was also developed and validated. The depsides (lecanoric acid, gyrophoric acid, atranorin, anziaic acid and 2'-O-methyl anziaic acid), and dibenzofurane (usnic acid) were identified in these lichens. The antioxidant activity (IC50) of lichens extracts ranged from 121.52 to 424.51 μg/ml. 2'-O-Methyl anziaic acid showed the highest antimicrobial activity with MIC ranging from 0.0625 to 1 mg/ml. M. subaurifera extract showed the highest cytotoxic activity against the tested cell lines (IC50 = 9.88 to 31.64 μg/ml).

Chemical composition and bioactive properties of the lichen, <i>Pleurosticta acetabulum</i >

“…Compared to bacteria, fungi are more resistant due to the more complex structure of the cell wall [3]. Similar to this research, the acetone extract of the lichen P. acetabulum and its major compound norstictic acid were previously tested for anti-proliferative activity towards HT29 cells [20].…”

“…A great diversity of living organisms can be used for the improvement of human health, such as biologically active components extracted from the plants, mushrooms and lichens [1][2][3]. In searching for new therapeutic alternatives, many different lichen species were investigated, due to significant antiviral, antimicrobial, anticancer, antihyperglycemic, cardioprotective, antiparasitic, anti-inflammatory and antibiotic effects that they have exhibited so far [3][4][5].…”

“…In searching for new therapeutic alternatives, many different lichen species were investigated, due to significant antiviral, antimicrobial, anticancer, antihyperglycemic, cardioprotective, antiparasitic, anti-inflammatory and antibiotic effects that they have exhibited so far [3][4][5].…”

Cytotoxic and Antimicrobial Activity of Dehydrozingerone based Cyclopropyl Derivatives

“…In these experiments, antibacterial effect was observed against the both Gram ‐positive and Gram ‐negative bacteria but it should be noted that the Gram ‐negative bacteria were more resilient. It has been generally reported that the Gram ‐negative bacteria are more resistant than Gram ‐positive . This resistance is likely, due to the fact that Gram ‐negative bacteria have a wall which itself is surrounded by an outer complex membrane, slowing down the passage of hydrophobic compounds.…”

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“…Lichens and their metabolites are shown to possess antibacterial activity against various pathogenic bacteria including antibiotic resistant bacteria. [9,[32][33][34][35][36][37][38] In this study, we evaluated the potential of H. incana to inhibit Gram-positive and Gram-negative bacteria by agar well diffusion method. The presence of an inhibition zone around the well is an indication of antibacterial potential of extract.…”