Comparison of antioxidant capacities of two Ganoderma lucidum strains of different geographical origins

Ganoderma lucidum, used in a traditional Chinese medicine, represents one of the most important medicinal mushrooms in the world, whose fruiting bodies and spores have been traditionally used because of a wide spectrum of biological activities such as antidiabetic, antioxidative, antiproliferative, cardioprotective, etc. Its ethnomedicinal importance in some parts of the Balkan region (Serbia and Croatia) is almost totally unknown and there should be more scientific investigations carried out. The aim of this work was to make a comparative study of antioxidative activities and total phenolic content of ethanol and hot water extracts of G. lucidum, collected from forests in Serbia (Morovićke šume, Fruška Gora) and Croatia (Donji Lapac, Plješevica). The present study was carried out to evaluate antioxidant potential of examined extracts via scavenging potential on ABTS, DPPH, OH∙ and NO∙ radicals, as well as of chelating effects via FRAP assay, together with determination of their total phenolic content. Results showed that both GLS extracts possessed better antiradical activities (IC50=0.23±0.01 for H2O and 2.75±0.01 μg/mL for EtOH for OH∙ and DPPH assay, respectively) than in the ABTS assay (151.40±1.07 mg TE/g d.w. for EtOH), while the phenolic content was generally equal in extracts of Serbian and Croatian samples (60.74±0.57 mg GAE/g d.w. for EtOH and 77.10±0.27 mg GAE/g d.w. for H2O, respectively). Therefore, these extracts could be considered as a good source of natural antioxidants. These results showed that examined G. lucidum extracts (especially Н2О) contain high amount of phenolic content which could significantly enhance the antiradical potential and reduce potential on iron ions. This is the first study reporting the comparison of antioxidant activities and phenolic contents of two different extracts between two G. lucidum strains from two different geographical origins from the Balkan region. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 43002]