药用真菌灵芝液体培养过程中的抗氧化活性研究

灵芝Ganoderma lingzhi是一种重要的药用真菌,已被《中国药典》正式收录。本研究主要以菌丝体干重、多糖含量、多酚含量、黄酮含量、抗坏血酸（ascorbic acid,AA）含量、总抗氧化能力（total antioxidant capacity,T-AOC）、超氧化物歧化酶（superoxide dismutase,SOD）活性、羟自由基清除能力、超氧阴离子清除能力、1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力、2,2′-连氮-双(3-乙基苯并噻唑-6-磺酸)2,2′-azino-bis(3- ethylbenzthiazoline-6-sulphonic acid),ABTS]自由基清除能力、铁离子还原能力（ferric reducing antioxidant power,FRAP）和亚铁离子螯合能力为测定指标,对灵芝液体培养过程中的抗氧化活性进行了评价。结果显示,该菌具有较高的抗氧化活性,体现在液体培养过程中生长代谢旺盛,可分泌大量多糖、多酚、黄酮、AA等物质和SOD等酶类,对羟自由基、超氧阴离子、DPPH自由基及ABTS自由基等的清除效果显著,且具有较强的铁离子还原能力和亚铁离子螯合作用,这也说明该菌的抗氧化活性与其自身的生长状况、次级代谢产物分泌及还原能力等密切相关。此外,一定的环境胁迫压力也可以激发该菌启动自身的抗氧化系统以保护机体免受氧化损伤。

Antioxidant activities of medicinal fungus Ganoderma lingzhi in the process of liquid cultivation

Ganoderma lingzhi has been officially included in Chinese Pharmacopoeia. Based on the tested indicators including mycelial dry weight, polysaccharide content, polyphenol content, flavonoid content, AA content, T-AOC, SOD activity, hydroxyl radical scavenging activity, superoxide anion scavenging activity, DPPH radical scavenging activity, ABTS radical scavenging activity, FRAP, and ferrous ion chelating activity, the antioxidant activities of G. lingzhi were evaluated in the condition of liquid cultivation. The results showed that G. lingzhi had higher antioxidant activities, accelerating vigorous growth and metabolism of the fungus. Under the condition of liquid cultivation, large amounts of polysaccharide, polyphenol, flavonoid, and AA content and SOD activities were detected. The fungus exhibited remarkable scavenging activities against hydroxyl radicals, superoxide anions, DPPH radicals, and ABTS radicals. Stronger FRAP and higher ferrous ion chelating activity were also notable. It was suggested that the antioxidant activity of the fungus was closely related to mycelial growth, secondary metabolism secretion, and reduction capacity. Certain environmental stress can also stimulate the fungus to activate its antioxidant system to protect itself from oxidative damage.