Antioxidant activity of lichen Cetraria aculeatas

Abstract

The aim of the present study is to investigate the antioxidant properties of the lichen Cetraria aculeata. Antioxidant activity of the methanol and ethyl acetate extracts of lichen was tested by different methods including determination of total phenolics content, determination of total antioxidant capacity, DPPH free radical scavenging activity, inhibitory activity towards lipid peroxidation, ferrous ion chelating ability and hydroxyl radical scavenging activity. The extracts of the lichen C. aculeata showed significant antioxidant activity. The methanol extract showed higher values for total phenolics and total antioxidant capacity compared to the ethyl acetate extract, while the ethyl acetate extract demonstrated better results for DPPH radical scavenging, inhibitory activity towards lipid peroxidation, chelating ability and hydroxyl radical scavenging than the methanol extract. This is the first report of the antioxidant properties of Cetraria aculeata growing in Serbia. The results of antioxidant activity indicate the application of this lichen as source of natural antioxidants that could be used as a possible food supplement, in the pharmaceutical industry and in the treatment of various diseases.Keywords: ROS, antioxidant activity, lichen, Cetraria aculeata. INTRODUCTIONActive oxygen exists in different forms, such as superoxide anion radicals (O2• −), hydrogen peroxide (H 2 O 2 ), hydroxyl radicals (OH•) and singlet oxygen ( 1 O2). These forms of oxygen are highly reactive intermediates, and have a collective name of reactive oxygen species (ROS) [1,2,3,4,5]. ROS are free radicals very important for living organisms, in which are formed in different ways. In normal aerobic respiration, stimulated polymorphonuclear leukocytes and macrophages, and peroxisomes appear to be the main endogenous sources of most oxidants produced by cells. However, despite the fact that ROS are necessary for cell function, in high concentrations leads to oxidative stress and to the development a large number of diseases such as arthritis, carcinogenesis, aging. In addition to endogenous sources of free radicals, a major contribution of the accumulation of free radicals in cells are provided by exogenous sources such as ionizing radiation, tobacco smoke, certain pollutants, organic solvents and pesticides [4,6,7,8,9,10]. The above mentioned diseases and accelerated aging are the consequence of oxidative tissue damage by free radicals because of unbalanced mechanisms of antioxidant protection under the influence of endogenous and exogenous factors [11]. ROS attack unsaturated fatty acids in membrane proteins, causing lipid peroxidation, and the result is damage to membrane proteins [12]. This leads to reduced permeability of membranes, receptors and enzyme activity, and reduced activation of cells. Free radicals attack the DNA, while leading to DNA damage, resulting in mutations that cause cancer. Therefore, the prevention of many diseases are important antioxidant defense systems, including food, drugs and antioxidant enzymes [1...

The Genus Cetraria s. str.—A Review of Its Botany, Phytochemistry, Traditional Uses and Pharmacology

“…aculeata increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes’ activities. On the contrary, a slight increase in malondialdehyde (MDA) levels and a decrease in reduced glutathione (GSH) levels were also observed at low doses [ 112 ].…”

“…solani , Rhizopus sp, Aspergillus sp. Antifungal No antifungal activity detected [ 13 ] Acetone extract TA98 and TA100 strains of S. typhimurium Antigenotoxicity ↑ Inhibition of frameshift mutations in TA98 than in TA100 [ 129 ] Methanol extract Salmonella typhimurium TA1535 and TA1537 E. coli WP2uvrA Human lymphocyte cells Antigenotoxicity Antimutagenic activity against Salmonella typhimurium No activity against E. coli ↓ formation of SCE [ 14 ] Methanol extract Ethyl acetate extract Radical scavenging activity Antioxidant Methanol extract >>> ethyl acetate extract Methanol extract: DPPH (IC 50 51.6 µg/mL); lipid peroxidation inhibition capacity (IC 50 45.5 µg/mL); ferrous ion chelating capacity (IC 50 50.4 µg/mL; hydroxyl radical scavenging activity (IC 50 90.1 µg/mL) [ 112 ] Methanol extract Human lymphocytes cells Antioxidant ↑ SOD, GPX, MDA levels ↓ GSH [ 14 ] Acetone extract HeLa cells, A549 cells and 5RP7 cells Cytotoxic ↓ Cell viability [ 129 ] …”