LICHENS WITH HIGH ANTIOXIDATIVE ACTIVITY

Abstract

Introduction. Lichens are an evolutionary formed symbiotic organism between a mycobiont and a photobiont. About 600 unique lichen ingredients have been identified so far. Some of lichen ingredients are reported to possess a broad spectrum of pharmacological activities, related to its antioxidant properties. In the Russian Federation, the lichens possess  a high biological activity, but they  are the waste while  in forestry, unfortunately. So, the aim of the study is a screening of different lichens for their ability to absorb metals and lichen extracts for the antioxidant activity. To achieve  the purpose, the following  methods were used. The content of micro- and macro elements was measured by an atomic absorption spectroscopy. For the extraction, two methods were used: extraction by Soxhlet apparatus for 4 hours with chloroform as a solvent and maceration for 24 hours with hexane, dichloromethane and acetonitrile (consequently) as solvents. The antioxidant activity was distinguished with the measuring of the phospho-molybdenum solution color change. Data was expressed as milligrams extract equivalent to grams of gallic acid (mg/g GA) averaged from 3 or more. The total phenols content of the extracts was evaluated by Folin-Ciocalteu method. Data was calculated as milligrams of extract equivalent to grams of ascorbic acid (mg/g AA) averaged from 3 or more. The ability of extracts to protect cells from reactive forms of oxygen was tested using cell line (human skin fibroblasts) stimulated with extracts and H₂O₂. The protection ability was calculated like difference between viability of the cells treated with extract and H₂O₂ and viability of the cells treated with H₂O₂. Results. Among macroelements, potassium, calcium and iron are found in significant quantity. Manganese does not exceed the maximum concentration limit (MCL). The content of microelements is insignificant and does not exceed the MCL. All of fractions from Cladonia arbuscula showed significantly high antioxidant activity. Antioxidant activity of E.prunasrti is quite less. But the acetonitrile extract from E. prunastri comparing to other tested extracts shows ability to protect cells from reactive forms of oxygen (H₂O₂). Conclusion. Extracts from lichens of Mari El region show antioxidant activity in vitro. Moreover, micro- and macroelements content of lichens does not exceed the MCL. So, screening of broad biological activity with depth investigations of the different modes of action is required for drug development.