Study On Antioxidant’s Neuroprotective Effect And Its Mechanism Toalzheimer’s Disease

Part I: Clinical research on antioxidant probucol treatment ofAlzheimer’s diseaseObjective: To compare therapeutic effect of Alzheimer’s disease by probucol joint withDonepezil multi-naphthalene and only by Donepezil multi-naphthalene.Methods:40cases of Alzheimer’s disease have been collected and randomized intocombination therapy group or monotherapy group by single-blind control method with afollow-up time window up to8weeks. Cognitive function and clinical efficacy has beenmeasured both before the treatment and at the eighth week, using simple mental statescale (MMSE).Results:8weekend MMSE score: Combination therapy group shows difference beforeand after the treatment, which was statistically significant (P <0.01); the differencebefore and after the treatment of monotherapy was not statistically significant (P>0.05);the two groups have no statistically significant (P<0.05) difference after8weekends.Conclusion: The treatment of probucol combined with Donepezil multi-naphthalenehas better effect on improving cognitive function in Alzheimer’s disease. Part II: Research on luteolin’s neuroprotection and its mechanism in vitro model ofAlzheimer’s diseaseObjective: To investigate luteolin (Luteolin) in neuroprotective mechanisms ofoxidative damage in vitro model of Alzheimer’s disease created by Aβ25-35-inducedhuman neuroblastoma cells (SH-SY5Y cells).Methods:50μmol/L concentration SH-SY5Y cells induced by Aβ25-35were used intoestablishment of vitro model of Alzheimer. Doses of different concentrations of luteolinhave been used into intervention for vitro models ofAD. Experimental groups are:1. Normal group for comparison: normal cultured SH-SY5Y cells;2.AD vitro model group:50μmol/L forAβ25-35-induced SH-SY5Y cells;3. Treatment group1:1μmol/L luteolin intoAD vitro model;4. Treatment group2:5μmol/L luteolin intoAD vitro model;5. Treatment groups3:10μmol/L luteolin intoAD vitro model;6. Treatment groups4:20μmol/L luteolin intoAD vitro model;An inverted microscope was used into observing morphological changes and antransmission electron microscope was used into observing ultrastructure changes ofcells; Cell viability was checked by MTT in each group; Microplate method was usedinto detection of lactate dehydrogenase (LDH) activity; Flow cytometry detected theapoptotic rate; By measuring malondialdehyde (MDA) content, total glutathione (GSH)content and measurement of superoxide dismutase (SOD) activity, the extent of cellularoxidative damage has been assessed.Results:(A) morphological observation:1. Normal group for comparison: the number of cells was large under lightmicroscopy. Cell individuals were plump with obvious synapses, and interwoven into anetwork. Nuclear edge was smooth. Intracytoplasmic rough endoplasmic reticulum,ribosomes, mitochondria and other organelles lysosomes were clearly visible.2.AD vitro model group: the number of cells was significantly reduced under lightmicroscopy. Cell structure disappeared. Cells showed polygonal or irregular in shapewith poor growth state. Electron microscopy showed irregular nuclei and prominent nucleoli were distributed to the edge. There was also swelling organelles and messyoverall structure.3.Treatment group1-3: Under light microscope, with drug concentrationsincreasing, the number of cells significantly increased, the presence of cell structure,cell protrusions dense. With the increase of drug concentration under the electronmicroscope.sleek nucleolus and nuclear membrane progressively structured, increasedcytoplasmic organelles.It’s mitochondria gradually clear.The structure gradually tonormal cells close.4.Treatment groups4: light microscope rare clear cell structure, axons and dendritesbroken, messy woven into the fiber structure group, cell disruption, cytoplasmcytoplasm is not obvious.The growth of state and refraction were poor, cells the extentof the damage is very serious, nuclear shrinkage, organelle less severe structuraldamage.Clutter is difficult to distinguish the overall structure.(B) assessment of neuroprotection1.Compared with normal control group:MTT absorbance OD values in vitro cellviability AD model group were significantly decreased (P<0.01).LDH activity andapoptosis were significantly elevated (P <0.01).2.Compared with AD in vitro model group:Treatment group of1-3OD MTTabsorbance values increased (P <0.05).Cell survival was significantly improved (P<0.01), LDH activity was significantly lower (P <0.01).Apoptosis rate decreased (P<0.05).Treatment groups3’s MTT absorbance OD values and reached the highest cellviability.LDH activity and apoptosis rate was the lowest.3.Compared with AD in vitro model group:Treatment with cell survivalabsorbance OD value of4groups were lower (P <0.05).LDH activity and apoptosis rateincreased significantly (P <0.01).(C) the degree of oxidative damage assessment1.Compared with normal control group, it was significantly increased. MDAcontent in vitro model of AD group (P <0.01).SOD activity was significantly lower (P<0.01).GSH content was significantly lower (P <0.01). 2.Compared with AD in vitro model group:Treatment group1-3MDA contentdecreased (P <0.05).SOD activity was significantly improved (P <0.01).Total GSHlevels improved significantly (P <0.01). Treatment groups3’s reached the lowest levelsof MDA.SOD activity and the highest total GSH content.3.Compared with AD in vitro model group therapy significantly elevated MDAlevels4group (P <0.01).SOD activity was significantly lower (P <0.01).Significantlydecreased GSH content (P <0.01).Conclusion:1.Low doses of luteolin in vitro models for AD have neuroprotective effects.2.This neural mechanisms of the protective effect may be due to reduction in the degreeof oxidative damage caused byAD in vitro models.3.When luteolin dose to a certain extent, the neuroprotective effect of luteolin intocytotoxicity.