| Ganoderma Lucidum (GL) is one of the most famous traditional Chinese tonics and drugs. Selenium is an essential trace element for human beings. Studies on the use of Ganoderma Lucidum to biotransform selenium have not been reported overseas and seldom reported domestically. Therefore, the objective of this paper is to carry out comprehensive research in the field of Se-enriched Ganoderma Lucidum (Se-GL) to explore a new source of Se supplement and more effective bioactive components. The main results of this paper are as follows.The Se-GL with good yield and high Se content could be obtained by cultivating Ganoderma Lucidum in the substrate with Se content of 200~250u.g/g. Low concentration of Se (< 100 ug/g) in the substrate facilitated the synthesis of total protein and amino acids in Ganoderma Lucidum, but high concentration of Se (> 150 u.g/g) played a reverse role. However, Se of all concentration facilitated the synthesis of polysaccharides. Se concentration in the culture had no significant effect on the distribution of the amino acids and proteins. Additionally, the effect of Se on the contents of mineral elements of Se-GL was rather complicated. With the increase of Se content in Se-GL, the contents of Cu and Mo increased, however, the contens of other elements such as Fe, Ca, and Sr decreased.In Se-enriched Ganoderma Lucidum (GL), most selenium (>80%) was in organic forms and incorporated into proteins probably in the form of seleno-cysteine. Furthermore, water- and alkaline-soluble protein components were mainly (>75%) responsible for the storage of organic Se. Additionally, SDS-PAGE separation and HGAFS analysis for selenium content showed that 13 proteins or peptides with molecular weight between 8.709 and 142.53 kDa contained more or less selenium. However, most selenium was bound to the proteins or peptides with molecular weight no more than 16 kDa.The seleno-protein with highest Se content of 5.48 mg per gram of protein extracts from Se-GL could be obtained using gel filtration column chromatography (Sephadex G-100) and strong anion-exchange column chromatography (Biorad High Q). The antioxidant activity of resultant purified seleno-protein was stable under 60 ℃. Moreover, the isoelectric point of protein extracts from Se-GL was about 4.2 of acidity value.Data from spin trapping experiments and chemiluminescence analysis using CuSO4-Phen-Vc-H2O2-DNA system showed that both protein extracts and polysaccharide extracts from Se-GL (Se-GLPr and Se-GLP) could effectively scavenge hydroxyl and superoxide radicals andboth exhibited higher activities of antioxidant than their analog, common Ganoderma Lucidum protein and polysaccharide extracts. There was a synergistic effect between selenium and Se-GLPr on antioxidant activity. However, the same situation was not found between selenium and Se-GLP and between Se-GLPr and Se-GLP. Selenium, Se-GLP, and Se-GLPr could enhance each other antioxidant activity. Se-GLPr could not only definitely inhibit the intensity of chemiluminescence induced by both DNA damage and Phen oxidation but also obviously delay the time of appearance of the two peaks of chemiluminescence. Moreover, there was a linear relationship between the concentrations of Se-GLPr and the delay time, indicating that Se-GLPr played its role as an antioxidant through a dual mechanism. Additionally, the protection of Se-GLPr against oxidative damage to rat erythrocytes was also studied. The results showed that Se-GLPr inhibited hemolysis and MDA production of erythrocytes in a dose dependent manner and prohibited the formation of methemoglobin so that protected the erythrocytes against oxidative damage.In general, Se-GL is a good source of Se supplement, and the protein extracts from Se-GL are another class of effective bioactive factors beside polysaccharide extracts from Se-GL, which are worthy of being further studied and widely applied.
|
PDF Full Text Request