对神经元氧化应激损伤具有保护活性的灵芝化合物体外筛选及作用机理OA北大核心CSTPCD

[Objective]Screening for compounds in Ganoderma lucidum that had neuroprotective activity and explo-ring their corresponding mechanisms of action,to provide scientific basis for the research and development of functional foods,health products and drugs with the effects of preventing and treating Alzheimer disease(AD).[Method]This study established a cellular model based on β-amyloid protein(Aβ)induced oxidative damage,and screened the antioxi-dant activity of G.lucidum alcohol extracts preliminarily assessed by the 1,1-diphenyl-2-trinitrophenylhydrazine(DPPH)free radical scavenging method,iron ion reduction/antioxidant capacity test,and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)ammonium salt(ABTS)free radical scavenging method,and evaluated their neuronal protective activity.Furthermore,the 4 triterpenoids compounds related to antioxidants in G.lucidum alcohol extracts were used to verify their activity and to explore their related mechanisms through surface plasma resonance technology.[Result]The results of in vitro physicochemical primary screening and cellular level screening experiments on DPPH and ABTS free radical scavenging,iron ion reduction/antioxidant capacity indicated that 6 G.lucidum alcohol extracts(108,161,106-2,171,173 and 109)had strong antioxidant protective activity for neurons,among which samples 108,109 and 106-2 showed the best protective effects against oxidative stress damage in rat adrenal pheochromocytoma(PC12)cells.The G.lu-cidum alcohol extracts could exert neuroprotective effects by alleviating cell cycle disruption,inhibiting early cell apopto-sis,enhancing superoxide dismutase(SOD)activity and glutathione(GSH)content,and suppressing the increase of malondialdehyde(MDA)content.The average contents of 4 triterpenoids(ganoderal A,ganoderic acid B,ganoderic acid C2,and ganoderic acid LM2)in G.lucidum alcohol extracts numbered 108,106-2 and 109 were relatively high.Ac-tivity validation demonstrated that these 4 compounds all exhibited obvious reparative effects against cellular oxidative stress damage.Among them,ganoderal A and Aβ1-42 showed strong affinity,with a KD value of 15.62 μmol/L,and could inhibit the binding of Aβ1-42 to RAGE through competitive binding with Aβ1-42.[Conclusion]The antioxidant neuronal ac-tivity of G.lucidum ethanol extracts is achieved through the synergistic effects of 4 compounds:ganoderic acid C2,ganoderic acid B,ganoderic acid LM2 and ganoderal A.Ganoderal A can alleviate or inhibit the cytotoxic effects of Aβ1-42 by competitively binding with RAGE.G.lucidum has the potential for developing into a functional product for the preven-tion and treatment of AD.