H_(2)O_(2)对北苍术次生代谢影响及机制分析

Effect of H_(2)O_(2)on Secondary Metabolism in Atractylodes chinensis and Its Mechanism

目的:探讨外源H_(2)O_(2)对北苍术次生代谢的影响及其机制。方法:采用5.0、1.0、0.2、0.04 mmol·L^(-1)H_(2)O_(2)溶液和清水处理北苍术鲜根,比较北苍术内活性氧含量、抗氧化酶活性、次生代谢产物关键酶活性及次生代谢产物含量之间的关系。结果:在外源H_(2)O_(2)的作用下,北苍术鲜根中活性氧和丙二醛(MDA)的含量在第4天有显著升高,并在第6~8天恢复至正常水平。超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性均呈现先上升后下降的趋势,SOD、CAT和POD的活性分别在第4、4~6、2~4天达到高峰。北苍术次生代谢产物关键酶羟甲基戊二酸单酰辅酶A还原酶(HMGR)、乙酰辅酶A羧化酶(ACC)活性均有显著提升,且在不同浓度H_(2)O_(2)处理中,0.2 mmol·L^(-1)H_(2)O_(2)处理组次生代谢产物合成关键酶活性提高幅度最大,促进北苍术次生代谢产物的生物合成量最多,0.2 mmol·L^(-1)H_(2)O_(2)处理组第6天苍术素、β-桉叶醇、苍术酮、白术内酯Ⅱ、白术内酯Ⅲ含量分别比对照提升了89.5%、108.7%、308.8%、64.7%和9.3%。结论:北苍术抗氧化酶和次生代谢产物共同作用维持机体活性氧的平衡,外源H_(2)O_(2)可显著提高北苍术药材质量。

Objective:To investigate the effect of exogenous H_(2)O_(2)on secondary metabolism in Atractylodes chinensis and its mechanism.Method:Fresh rhizomes of A.chinensis were treated with 5.0,1.0,0.2,0.04 mmol·L^(-1)H_(2)O_(2)solution and clean water,and the relationships between the contents of reactive oxygen species,activities of antioxidant enzymes,activities of key enzymes of secondary metabolites,and contents of secondary metabolites in A.chinensis were compared.Result:Under treatment with exogenous H_(2)O_(2),the content of reactive oxygen species and malondialdehyde(MDA)in the fresh rhizomes of A.chinensis were significantly elevated on the 4th day,and returned to normal level on the 6th-8th day.The activities of superoxide dismutase(SOD),catalase(CAT)and peroxidase(POD)were all increased first and then decreased,and reached the peak on the 4th,4th-6thand 2th-4thday,respectively.The activities of 3-hydroxy-3-methyl glutaryl coenzyme A reductase(HMGR)and acetyl CoA carboxylase(ACC),key enzymes of the secondary metabolites,were remarkably enhanced,and under treatments with different concentrations of H_(2)O_(2),the activities of key synthetic enzymes of the secondary metabolites in 0.2 mmol·L^(-1)H_(2)O_(2)group were increased most,with the highest biosynthesis of secondary metabolites.The contents of atractylodin,β-eudesmol,atractylone,atractylenolideⅡ,and atractylenolideⅢon the 6th day of 0.2 mmol·L^(-1)H_(2)O_(2)treatment were89.5%,108.7%,308.8%,64.7%and 9.3%,respectively higher than those in the control.Conclusion:The antioxidant enzymes and secondary metabolites in A.chinensis synergistically maintain the balance of reactive oxygen species,and exogenous H_(2)O_(2)can improve the medicinal quality of A.chinensis remarkably.