Study On The Antagonism Of Chlorogenic Acid To Aluminum Exposure And Its Mechanism

Aluminum(Al)exposure has a wide range of ways and unpredictable exposure doses,so it is difficult to avoid the toxic effects of A1 on human body.It has become a modern method to antagonize the toxicity of All by chelating agents and natural antioxidants.This study explored the protective effect and mechanism of chlorogenic acid(CGA,5-O-caffeoylquinic acid)on AlCl3 toxicity at animal and cell levels.Firstly,the prophylactic and protective effects of CGA on hepatotoxicity and hematotoxicity induced by acute AICll3 exposure in mice were investigated.Eight-week-old male Kunming mice were injected with 30 mg/Kg CGA for 5 days or 100 mg/Kg CGA for 1 day before or after acute AICl3 exposure(25 mg AIC13/Kg single intraperitoneal injection),The results showed that,compared with the control group,acute AlCl3 exposure resulted in significant increases in liver and blood Al(?)levels,serum aminotransferase activities and the erythrocyte osmotic fragility,and significant decreases in endogenous antioxidant enzyme activities in mice.However,CGA treatment before and after AlCl3 exposure could alleviate the oxidative damage of AlCl3,stabilize cell membrane and prevent hepatocyte apoptosis,and CGA pretreatment showed a strong scavenging effect on AlCl3 toxicity.On the basis of animal experiments,we selected PC 12 cells to observe the protective effect of CGA on AIC13-induced cytotoxicity in vitro.After 24 h of treatment with AlCl3 alone or in combination with gradient concentration of CGA,the cell viability of CGA group was significantly higher than that of Al group.DAPI staining and scanning electron microscopy showed that CGA alleviated the nuclear coagulation and the apoptotic morphology of cells becoming smaller and rounder.The oxidative damage index showed that CGA reduced the oxidative stress level induced by AlCl3.ICP-MS determination of intracellular Al(?)levels and the localization of Al(?)showed that CGA could reduce the accumulation of intracellular Al(?).In addition,CGA significantly reduced the apoptotic rate,Bcl-2/Bax protein ratio and the cytochrome c expression.These results suggest that CGA has a protective effect on AlCl3-induced PC 12 cytotoxicity in a dose-dependent manner.On the basis of observing the toxicity scavenging effect of CGA on AlCl3,we intervened with 10 ?M CGA before,after,and at the same time of AlCl3 damage to explore the mechanism of CGA on AlCl3 in PC12 cells.The results showed that the cell damage of each group treated with CGA was significantly lower than that of the Al group,and the best effect was shown when CGA and AlCl3 were treated together.The determination of intracellular Al(?)levels and the localization of Al(?)showed that CGA inhibited the entry of Al(?)by chelating with extracellular Al(?),thereby reducing the biological transport of Al(?)and alleviating AIC13-induced cytotoxicity.Simultaneously,CGA can significantly slow down cell G0-G1 arrest,and then improve the viability of PC 12 cells.In addition,the intervention of CGA activated the Akt and GSK-3? protein effectively,and play a neuroprotective role by regulating Akt/GSK-3? signaling pathway to reduce the production of A?1-42 induced by AlCl3.In conclusion,the antagonistic effect of CGA on Al exposure has been proved at animal and cell levels,which provides a theoretical basis for the prevention and treatment of foodborne Al exposure.