| ObjectivesWith the development of industry,people have more and more ways to contact and absorb aluminum.Aluminum can accumulate in the body and cause chronic toxicity.Studies have shown that the accumulation of high-dose aluminum can lead to neurotoxicity and cause clinical symptoms such as memory loss,tremor,convulsion and ataxia.At present,the mechanism of aluminum acting on these symptoms and pathological conditions is not clear.Most studies believe that aluminum is related to the oxidative damage caused by the increase of free radical content in tissues.Flavonoid compounds having significant free radical scavenging and antioxidant effects,can improve lipid metabolism,and is a metal chelating agent.In this study,aluminum poisoning model of rats was established by aluminum chloride hexahydrate gavage.Then,the protective effects of flavonoids on the regulation of neurotransmitters and the antioxidant system in aluminum poisoned rats were investigated by measuring the peroxidation index,related trace elements,ATP activity,monoamine neurotransmitter and amino acid neurotransmitter content.Methods1.Experimental animals64 male rats of SPF grade were randomly divided into eight groups:control,Al-treated,low-dose rutin,high-dose rutin,low-dose silymarin,high-dose silymarin and low-dose puerarin,high-dose puerarin.The control group received 1 mL/(kg·day)saline solution for 12 weeks.The other groups were exposed to Al at a dose of 281.40 mg/kg/day orally for 4 weeks.Then,they were respectively received 1mL/kg/day saline solution,100mg/(kg·day)rutin,200 mg/(kg·day)rutin,100mg/(kg·day)silymarin,200mg/(kg·day)silymarin,100mg/(kg·day)puerarin,and 200 mg/(kg·day)puerarin for 8 weeks.The tested chemicals were given by gavage.After the detoxification phase,rats in each group fasted 24h after the last administration,then the rat was decapitated,the brains were quickly removed,cleaned of adhering matters and washed with normal saline.All tissue samples were stored at-80℃ until required analysis.2.Effects of flavonoids on general growth and development of aluminum exposed ratsThe mental state,food and water consumption of the experimental rats were observed daily.The rats were weighed twice a week,and the weight changes of the rats were observed and recorded.3.Effects of flavonoids on antioxidant system of cerebral cortex and serum of rats poisoned with aluminumThe cerebral cortex was taken out and weighed.Normal saline was added according to mass:volume =1:9 to prepare 10%homogenate.The serum was diluted with normal saline to the appropriate concentration,SOD,GSH-Px and MDA were determined according to the kit procedure4.Effects of flavonoids on ATPase activity in the cerebral cortex of rats exposed to aluminumThe cerebral cortex was taken out and weighed.Normal saline was added according to mass:volume =1:9 to prepare 10%homogenate.The serum was diluted with normal saline to the appropriate concentration.Na+K+-ATPase,Mg2+-ATPase and Ca2+-ATPase were determined according to the steps of the kit.5.Effects of flavonoids on some elements in brain tissue of rats poisoned with aluminumThe absorbance of 0.2g brain tissue was measured by flame atomic absorption spectrometry after microwave digestion,and the contents of Ca,Mg,Cu,Fe and Zn were calculated.6.Effects of flavonoids on monoamine neurotransmitters in rat brain tissue exposed to aluminumAn appropriate amount of brain tissue was accurately weighed and made into 10%brain homogenate of m(g):V(ml)=1:9 with perchloric acid solution(0.1mol/L).The contents of NE,E,DA and 5-HT in brain tissues of rats in each group were determined by HPLC and fluorescence detection.7.Effects of flavonoids on amino acid neurotransmitters in brain tissue of rats exposed to aluminumAn appropriate amount of brain tissue was accurately weighed and made into 10%brain homogenate by acetonitrile aqueous solution(50%).Then,amino acid neurotransmitters in tissue homogenate were derived by DNFB.The contents of Asp,Glu,Gly,Tau and GABA in rat brain tissue were determined by HPLC and diode array assay.Results1.Effects of flavonoids on growth and development of aluminum-poisoned ratsDuring the experiment,the observation found that the control group of rats in good health,good mental state,hair white shiny.With the increase of A1 exposure time,the rats in the aluminum exposure group showed growth retardation,mental malaise,sparse hair and lackluster.With the progress of the experiment,the weight of the rats in each group increased continuously.Compared to the negative control group,the body weight of rats in the aluminum poisoning group was lower from week 6(P<0.05).Compared to the aluminum group,the body weight of rats in the high-dose rutin and high-dose silymarin group was significantly higher from week 9(P<0.05).2.Effects of flavonoids on antioxidant system of cerebral cortex of rats exposed to aluminumCompared with the negative control group,the activity of SOD in the poisoned group was significantly decreased(P<0.05).Compared with the poisoned group,SOD activity was significantly increased in the rutin high-dose group,the silymarin low-dose group,and the silymarin high-dose group(P<0.05).,Compared with the negative control group,the activity of GSH-Px in the poisoned group was significantly decreased(P<0.05).Compared with the poisoned group,the activity of GSH-Px in the rutin high-dose group and the silymarin high-dose group was significantly increased(P<0.05).Compared with the negative control group,MDA content in the poisoned group was significantly increased(P<0.05).MDA content in rutin high dose group,puerarin high dose group and silymarin high dose group was lower than that in the poisoned group(P<0.05).Compared with that of the high-dose group,the three indexes of the three flavonoids fell into no significant difference(P>0.05).3.Effects of flavonoids on serum antioxidant system of aluminum-poisoned ratsThe activity of SOD in serum of rats exposed to aluminum was lower than that of control group.SOD activity increased in the serum of the rats of the detoxification groups,but the difference was not statistically significant(P>0.05).The serum GSH-Px activity in the aluminum exposed group decreased significantly compared with the control group(P<0.05).Compared with the aluminum exposure group,the activity of GSH-Px in the rutin high-dose group and the silymarin high-dose group was significantly increased(P<0.05).Compared with the negative control group,MDA content in serum of rats exposed to aluminum was significantly higher(P<0.05).Compared with the aluminum exposure group,MDA content in rutin high dose group,puerarin high dose group and silymarin high dose group was significantly lower(P<0.05).4.Effects of flavonoids on ATPase activity in the cerebral cortex of rats exposed to aluminumWith the intake of aluminum,Na+K+-ATPase,Mg2+-ATPase and Ca2+-ATPase activity in rat brain decreased.Compared with the control group,Na+K+-ATPase activity was significantly decreased in the brain tissues of rats exposed to aluminum(P<0.05).Compared with the aluminum exposure group,the Na+K+-ATPase activity of the high dose rutin group,the low dose silymarin group and the high dose silymarin group was significantly higher(P<0.05).The activity of Mg2+-ATPase in the brain tissue of rats exposed to aluminum decreased significantly compared with the control group(P<0.05).Compared with the exposed group,the activity of Mg2+-ATPase in rutin high dose group,puerarin high dose group and silymarin high dose group was significantly higher(P<0.05).Compared with that of the control group,the Ca2+-ATPase of the rat brain fell into a decline,but the difference was not statistically significant(P>0.05).The Ca2+-ATPase activity of the detoxification group increased compared with that of the collection group,but the difference showed no statistical significance(P>0.05).5.Effects of flavonoids on Ca,Mg,Cu,Fe and Zn in brain tissue of rats poisoned with aluminumCompared with the control group,the contents of Mg,Fe and Zn in rats exposed to aluminum were significantly decreased(P<0.05).Compared with the poisoned group,the Mg content in the high-dose rutin group,the high-dose puerarin group,the low-dose silymarin group and the high-dose silymarin group was significantly increased(P<0.05).Compared with the aluminum exposure group,Fe contents in low dose rutin group,high dose rutin group,high dose puerarin group and high dose silymarin group were all higher(P<0.05).The content of Zn in the high-dose puerarin group,low-dose silymarin group and high-dose silymarin group was significantly higher than that in the poisoned group(P<0.05).Compared with the aluminum poisoning group,the content of Ca and Cu in each detoxification group showed no statistical significance(P>0.05),but the content of Ca and Cu in the detoxification group was lower than that in the negative group and the detoxification group.6.Effects of flavonoids on monoamine neurotransmitters in rat brain tissue exposed to aluminumCompared with the control group,the content of NE in brain tissue of rats exposed to aluminum decreased significantly(P<0.05).Compared with the aluminum exposure group,the contents of NE in the brain tissues of rats in the rutin high-dose group,puerarin high-dose group,silymarin low-dose group and silymarin high-dose group were significantly increased(P<0.05).Compared with the negative control group,the content of E in the brain tissue of rats exposed to aluminum decreased significantly(P<0.05).Compared with the aluminum exposure group,the E content in the brain tissues of the rats in the puerarin high-dose group and the silymarin high-dose group was significantly increased(P<0.05).Compared with the control group,the content of DA in the brain tissue of rats exposed to aluminum decreased significantly(P<0.05).Compared with the aluminum exposure group,the DA content in the brain tissues of rats in the rutin high-dose group and the silymarin high-dose group was significantly increased(P<0.05).Compared with the control group,the content of 5-HT in the brain tissue of rats exposed to aluminum decreased significantly(P<0.05).Compared with the aluminum exposure group,the 5-HT content in the brain tissues of rats in the rutin high-dose group and the silymarin high-dose group was significantly increased(P<0.05).7.Effects of flavonoids on amino acid neurotransmitters in braintissue of rats exposed to aluminumCompared with the control group,the content of Asp in brain tissue of rats exposed to aluminum increased significantly(P<0.05).Compared with the aluminum exposure group,the content of Asp in the brain tissue of rats in the puerarin high-dose group,the silymarin low-dose group and the silymarin high-dose group decreased significantly(P<0.05).Compared with the control group,the content of Glu in brain tissue of rats exposed to aluminum increased significantly(P<0.05).Compared with the aluminum exposure group,the Glu content in the brain tissue of the rats in the low dose group,the high dose group and the low dose group of silymarin decreased significantly(P<0.05).Compared with the control group,the content of GABA in the brain tissue of rats exposed to aluminum decreased significantly(P<0.05).The contents of GABA in brain tissue of rats with high dose of rutin,high dose of puerarin,low dose of silymarin and high dose of silymarin were significantly higher than those of the aluminum group(P<0.05).Compared with the control group,Tau content in brain tissues of rats exposed to aluminum decreased significantly(P<0.05).Compared with the aluminum exposure group,Tau content in brain tissues of rats in the low dose group of rutin,the low dose group of silymarin and the high dose group of silymarin was significantly increased(P<0.05).Compared with that of the control group,the Gly content of the rat’s brain tissue fell after aluminum poisoning(P>0.05).Compared with that of the aluminum group,the Gly content of the brain tissues of the detoxification groups increased somewhat,but the difference showed no statistical significance(P>0.05).Conclusions1.Flavonoids can improve the growth retardation of aluminum poisoned rats.2.A certain dose of flavonoids can significantly improve the brain tissue and serum antioxidant system of rats exposed to aluminum.3.A certain dose of flavonoids can effectively increase the activity of Na+K+-ATPase and Mg2+-ATPase in the cerebral cortex of rats exposed to aluminum,but has no significant effect on the activity of Ca2+-ATPase.4.A certain dose of flavonoids play a role in improving and regulating the homeostasis imbalance of Mg,Zn and Fe in rat brain tissue caused by aluminum,but have no significant effect on the metabolism of Ca and Cu.5.Flavonoids can inhibit and improve the content disorder of amino acid neurotransmitter and monoamine neurotransmitter induced by aluminum in rats. |
PDF Full Text Request