Investigation of Antimicrobial and Antioxidant Activities of some Lichens

Abstract

This study investigated the antimicrobial and antioxidant properties of methanol extracts from five lichen species: Polycauliona candelaria (Syn. Xanthoria candelaria), Nephromopsis chlorophylla (Syn. Cetraria chlorophylla), Circinaria calcarea (Syn. Aspicilia calcarea), Bryoria capillaris (Syn. Alectoria cana), and Peltigera canina (Syn. Dermatodea canina). Antimicrobial activities were determined using the agar disc diffusion method, while minimal inhibitory concentration (MIC) values were determined using the micro-well dilution method. Among the lichen species, methanol extract of Circinaria calcarea exhibited the highest antimicrobial activity, with a 15 mm zone of inhibition against Escherichia coli and Bacillus cereus. It also demonstrated the lowest MIC value (31.25 μg/mL) against Bacillus cereus, Bacillus subtilis, Clostridium perfringens and Escherichia coli were the most sensitive microorganisms to lichens. Various antioxidant determination methods were employed to assess the antioxidant activities of the lichens, including ferric ion (Fe+3) reduction capacity, cupric ion (Cu+2) reduction capacity, ferric ion reducing antioxidant power (FRAP), DPPH radical scavenging activity, DMPD radical scavenging activity and metal chelating activity using the bipyridyl reagent. All lichens exhibited excellent antioxidant activity, particularly in metal chelating activity using the bipyridyl reagent. Peltigera canina demonstrated the highest antioxidant activity among the studied lichen species across most of the applied method.

Evaluation of In vitro Anticancer Activity (Ovarian Cancer Cells-pa1) and Zebrafish Embryo Toxicity of Parmelia perlata Ethanolic Extract

“…According to Kello et al, DPPH radical scavenging activities of lichen methanolic extracts increased proportionately with concentration. Absorbance values of these extracts and standard antioxidants were assessed at 24.75 µg/mL [9,12]. Further, Tartouga et al, the extract demonstrated a 38.39% inhibition of BSA denaturation at a concentration of 1000 µg/mL [23].…”

“…C. calcarea, N. chlorophylla, and B. capillaris showed significant effectiveness against B. cereus, B. subtilis, C. perfringens, and E. coli, resulting in ZOI ranging from 9 to 15 mm. In a study conducted by Us et al, it was shown that C. calcarea exhibited the most activity, resulting in a 15 mm inhibition zone against both E. coli and B. cereus [12]. The study assessed the antibacterial efficacy of solvent extracts derived from 12 lichen species against pathogenic bacteria (P. aeruginosa, E. coli, S. aureus, and K.…”

“…The radical scavenging activity of P. perlata was assessed using the DPPH assay [8][9][10][11][12]. A 1 mL solution of DPPH (0.1 mM) was combined with 3 mL of P. perlata extract at various concentrations (10-50μg/ml).…”

“…Gentamycin was used as the positive control. The plates were placed in an incubator at 37°C for 24 h. The antibacterial activity was evaluated by measuring the diameter of the inhibition zone [9,[12][13]17].…”