The Protective Effect Of Genistein On Beta-Amyloid-Induced Neuronal Mitochondrial Dysfunction And Potential Related Mechanism

Genistein (Genistein， Gen)， widely exists in leguminous plants， is one of the maincomponents of soy isoflavone aglycone. Gen is known as phytoestrogen because of thesimilar chemic structure to estradiol，perform dual effects as estrogenic and anti-estrogenic.Gen could protect and treat cardiovascular disease、osteoporosis and tumor. Studies showthat Gen has a significant protective effect on neuronal cells， and it can be used forprevention and treatment of senile neurodegenerative diseases such as AD (Alzheimer’sdisease). It is applied in pharmaceutical industry， nutritional products and so on. Theprevious cellular level studies showed Gen could be activate the PKC (Protein kinase C)signal transduction pathway， thereby regulating the α、β-secretase activity， inhibitingthe formation、deposition and toxicity of Aβ， decreasing the intercellular calciumconcentration， increasing the ratio of Bcl-2/Bax and play a neuroprotective effect. Atpresent，the study on neuroprotective effect of genistein in more depth，but more in-depthstudy about mitochondrial-mediated apoptosis signal transduction pathway is reported less.We will continue to further study the protective effect of Gen and its mechanism in cellularlevel in this paper. The concrete job are as follows:1. The research of genistein on beta-Amyloid-induced PC12cells mitochondrialmorphology and activity: To set up the AD cell model using PC12cells induced withβ-amyloid peptide (Aβ25-35). The PC12cells were pre-incubated with differentconcentrations Gen for2h， then cultured with Aβ25-35for24h. We detected cell viability by MTT assay; mitochondrial morphology were determined by themitochondrial fluorescence probe MitoTracker Green FM; the method of sodium2，6-dichlorophenol indophenol (2，6-DPIP) was used to determine the succinicdehydrogenase (SDH) activity; The spectrophotometry was used to detectNa+-K+-ATPase activity. The results revealed that， Gen could improvebeta-Amyloid-induced PC12cells mitochondrial morphology， increase mitochondrialsuccinate Dehydrogenase activity and Na+-K+-ATP activity.2. The research of genistein on beta-Amyloid-induced PC12cells Radical scavenging andoxidative stress: the fluorescence probe DCFH-DA was used to determine thegeneration of reactive oxygen species (ROS); Thiobarbituric acid (TBA) was used todeterminate malondialdehyde (MDA) content;and xanthine oxidation was used todetect superoxide dismutase (SOD) activity. The results revealed that， Gen couldreduce the generation of reactive oxygen species and MDA content， and increaseSOD activity on beta-Amyloid-induced PC12cells.3. The research of genistein on beta-Amyloid-induced PC12cells mitochondrialmembrane potential and membrane permeability: the fluorescent dye rhodamine123was used to detect mitochondrial transmembrane potential (ψ m); the assay of ELISAdouble antibody sandwich was used to detect intracellular cytochrome c concentration;The spectrophotometry was used to detect caspase-3activity. The results revealedthat， Gen could stabilize beta-Amyloid-induced PC12cells mitochondrialtransmembrane potential and reduce cytochrome c release，and inhibite the activity ofCaspase-3.The results revealed that， Gen could improve beta-Amyloid-induced PC12cellsmitochondrial morphology， stabilize mitochondrial transmembrane potential andmembrane permeability, increase vitality and oxidative stress and free radicalscavenging capacity, thus which inhibiting beta-Amyloid-induced PC12cells injuriesand mitochondrial dysfunction.