Antioxidant activity of water extracts from fruit body of Lentinus edodes enriched with selenium

Abstract

Shiitake (Lentinus edodes) belongs to medically important and delicious fungi. It is recognizable for its healing properties, excellent taste and rich aroma. According to the traditional Japanese and Chinese medicine, shiitake mushroom significantly increases the strength and vitality of the body. Shiitake contains immunostimulants, compounds that lower cholesterol, prevents clogging of blood vessels, regulates the pressure, balances blood sugar levels, regulates digestion, and improves the performance of respiratory organs by its antirheumatic and antiallergic activities. Shiitake is recommended to use as food, prevention and cure, usually in a form of a spice (dried and ground) or tea. It can be consumed fresh, too. The objective of this study was to test the effect of enrichment in selenium on antioxidant, reducing and free radical scavenging activity of water extracts from fruit body of Lentinus edodes. The fungus was enhanced by adding organic selenium, zinc (II) complex with the ligand 2.6-bis diacetylpyridine (selenosemicarbazon) and inorganic compounds (Na2SeO3) of selenium in nutritional substrate where the fungus was grown. The total selenium content in fruit body was around 50 ppm for the sample enriched with selenium originating from organic sources, and 80 ppm for the sample enriched with selenium from inorganic sources. Samples were prepared by extraction of fruiting bodies in heated water. The results indicated that water extracts of whole fruit bodies, from both control and mushrooms supplemented with selenium, had quite good antioxidant activity. However, there was no significant difference between the samples supplemented with selenium content and those that were not.Shiitake (Lentinus edodes) pripada grupi medicinski znacajnih i delikatesnih gljiva. Prepoznatljiva je po svojoj lekovitosti, izvanrednom ukusu i bogatoj aromi. Prema tradicionalnoj japanskoj i kineskoj medicini, gljiva shiitake znacajno povecava snagu i vitalnost organizma. Shiitake sadrze imunostimulanse, sastojke koji snizavaju holesterol, sprecavaju zacepljenje krvnih sudova, regulisu pritisak, uravnotezuju nivo secera u krvi, regulisu probavu, poboljsavaju rad disajnih organa, deluju antireumatski i antialergijski. Preporuka je da se shiitake koriste kao ukusna hrana, preventiva i lek, najcesce kao zacin (susene i mlevene) ili caj. Mogu se konzumirati i kao sveze pripremljene. Cilj rada bio je da se razjasni da li selen dodat u supstrat za gajenje gljive Lentinus edodes utice na redukciona svojstva ekstrakta, antioksidativnu aktivnost ekstrakta, kao i procena reaktivnosti ekstrakata prema radikalskim vrstama. Gljiva je obogacena selenom dodavanjem organskih, Zn (II) kompleks sa ligandom 2,6-diacetilpiridin bis (selenosemicarbazon), i neorganskih jedinjenja (Na2SeO3) selena u hranljivi supstrat na kojem je gljiva uzgajana. Ukupan sadrzaj selena u plodonosnom telu kretao se oko 50 ppm za uzorak obogacen selenom iz organskog izvora i 80 ppm za uzorak obogacen selenom iz neorganskog izvora. Uzorci su pripremljeni ekstrakcijom plodonosnih tela u zagrejanoj vodi. Dobijeni rezultati ukazuju na to da vodeni ekstrakti celih gljiva, kako kontrolnih tako i sa dodatkom selena, imaju dobru antioksidativnu aktivnost. Medjutim, nije primecena znacajna razlika izmedju uzoraka sa i bez sadrzaja selena. PR Projekat Ministarstva nauke Republike Srbije, br. 20049