The Treatment Mechanism In Curing Mice Poisoned By Aluminum And Toxicological Study Of DHPO

Objective It was evidenced by researching that the accumulation of aluminum in human bodies cound lead to chronic poisoning. Up to now, there is no efficacious therapeutic measure of diseases induced by aluminum poisoning. In the following experiment DHPO(1,2-dimethyl-3-hydroxy-4-pyridone) is used as a new type of aluminum chelating agent in mice, the treatment mechanism of DHPO in curing mice poisoned by aluminum and its toxicology are studied in a bid to provide theoretical foundation for seeking a safe and efficacious medicine for aluminum poisoning.Methods1. The synthesis of DHPOThe white crystal derived by heating 2-methyl-3-hydroxy-4-pyrones in the Methylamine water solution (CH₃NH₂) at 95-100℃ is DHPO.2. Toxicological experiment2.1 LD₅₀ experiment 50 healthy mice of Kunming strain(25 males and 25 females) were randomly divided into 5 groups according to their body weight.The animals were given the medicine solution with the lavage method and observed for one week, then the number of dead mice were recorded.2.2 Peripheral blood and bone marrow cell micronucleus experiment 120 healthy mice of Kunming strain(60 males and 60 fernales)were randomly divided into 5 groups according to their body weight: negative control group, Cyclophosphamide positive control group, 1/8LD₅₀ group, 1/4LD₅₀ group and 1/2LD₅₀ group. Then DHPO bone marrow cell micronucleus experiment 24 hours after the second and the seventh application of medicine were conducted.2.3 Sperm aberration experiment 150 healthy male mice of Kunming strain were randomly divided into 5 groups according to their weight:negative control group, Cyclophosphamide positive control group, 1/8LD₅₀ group, 1/4LD₅₀ group, 1/2LD₅₀group. The medicine was applied for 5 successive days. On the 14th, 28th, 35lh, 42nd and 70th day after the application of medicine, DHPO Sperm aberration experiment was earned out.3. Study on the treatment mechanism of DHPO in curing mice poisoned by aluminum72 healthy mice of Kunming strain(36 males and 36 females) were randomly divided into 6 groups according to the weight: negative control group, model group, DHPO low-dose group, medium-dose group, high-dose group and preventive group. AICI3 solution were given to the 5 groups except the negative control group to make aluminum-poisoned model in mice. DHPO were given to the preventive group while AIGI3 solution were applied. The negative control group and the model group were given physiological salt solution , the DHPO low-dose group, medium-dose group, high-dose group and the preventive group were given DHPO. The mice were killed after the last giving and then the blood serum, liver, kidney and brain tissues were taken out.3.1 Effect of removing aluminum The content of aluminum in the blood serum, liver, kidney and brain tissues of the mice were determined by the graphite furnace atomic absorption spectrometry.3.2 Effect on the trace element Zinc The content of Zn in the blood serum, liver, kidney and brain tissues of the mice were determined by the flame atomic absorption spectrophotometry.3.3 Effect of recovering the anti-oxidizing system The activities of SOD, GSH-PX and the content of MDA in the blood serum and the homogenate of liver, kidney and brain tissues of the mice were determined in every group.3.4 Effect of recovering the neurotransmitter in the centra] nervous system Theactivity of AchE in the blood serum and the homogenate of brain tissues of the mice were determined in every group.3.5 Pathomorphological observation of the hippocampus and liver cells The liver and Hippocampus of the mice were dyed with HE and pathomorphological observation.were carried out.Results1. The synthesis of DHPOThe results showed that the melting point and the infrared spectrum and nuclear-magnetic spectrum corresponded with the structural characteristics of the target compound.2. Toxicological experiment2.1 The LD50 experiment of DHPO The results showed that the LD50of DHPO was 562.34mg/kg. The 95% credibility range of DHPO fell within 501.19⁶30.96mg/kg..2.2 Peripheral blood and bone marrow cell micronucleus experiment The results showed that there were no significant differences in the I/8LD50 group and the I/4LD50 group in comparison with the negative control group(P>0.05);The peripheral blood and the PCE micronucleus rate of bone marrow cell of the I/2LD50 group were higher than that of the negative control group(P<0.05).2.3 Sperm aberration experimentThe results showed that there were no significant differences in the I/8LD50 group and the I/4LD50 group in comparison with the negative control group in observations conducted in the 14th, 28th, 35th, 42nd, and 70th day(P>0.05); While significant differences appeared between the I/2LD50 group and the negative control group in observations conducted in the 14lh, 28lh and 35th day(P<0.05); there were no significant differences between the 1 /2LD50 group and the negative control group in observations conducted in the 42nd day and 70th day(P>0.05).3. Study on the treatment mechanism of DHPO in curing mice poisoned by aluminum3.1 Effect of removing aluminum The contents of Al in the liver, kidney, brain and the blood serum in the medicine-treated groups were all lower than that of the model group (PO.05).3.2 Effect on the trace element zinc No significant differences existed among various groups in the contents of Zn in the liver, kidney, brain and the blood serum (P>0.05).3.3 Effect of recovering the anti-oxidizing system The results showed that in comparison with the corresponding data of the model group(P<0.05), significant differences existed in the negative control group in terms of the activities of SOD, GSH-PX and the content of MDA in liver, brain and the blood serum.;In comparison with the corresponding data of the model group (P<0.05) , significant differences existed in the medium-dose group in the liver, in the preventive group in terms of activities of SOD, GSH-PX and the content of MDA in the liver, and in the high-dose group in terms of the content of MDA in the liver.;No significant differences existed among various groups in the activities of SOD, GSH-PX and the content of MDA in kidney.;In comparison with the corresponding data of the model group(P<0.05), significant differences existed among the high-dose group and the preventive group in terms of the activities of SOD, GSH-PX in brain and among the medium-dose group and the preventive group in terms of the content of MDA in brain; In comparison with the corresponding data of the model group (PO.05), significant differences existed in the preventive group in terms of the activities of SOD, GSH-PX and the content of MDA in the blood serum and in the high-dose group in terms of the activity of GSH-PX in the blood serum; In comparison with the corresponding data of the negative control group(P>0.05), no significant differences existed among the medicine-treated groups in the terms of the activities of SOD, GSH-PX and the content of MDA in liver, kidney, brain and the blood serum.3.4 Effect of recovering the neurotransmitter in the central nervous system Theresults showed that the activity of AchE in the model group was higher than that of the negative control group (PO.05). In comparison with the model group (P<0.05), significant differences existed in the high-dose group, medium-dose group and the preventive group. No significant differences existed between the medicine-treated groups and the negative control group (P>0.05).3.5 Pathomorphological observation of the hippocampus and liver cells The liver and hippocampus damage had been found among aluminum-poisoned mice in the pathological examination, significant recovering could be observed in the medicine-treated groups.Conclusion DHPO is a compound with low toxicity. l/2LD50 group is, to some extent, capable of mutagenesis. I/2LD50 group have some degrees of reproductive toxicology, but can recover within 42 days. DHPO can effectively eliminated Al without removing trace element Zn. DHPO can counter the aluminum-induced aging of the neurotransmitter in the central nervous system. It can also enhance the activity of the antioxidant enzyme, reduce peroxidization of lipid and thus remarkably improve the Al-induced pathological damages of liver and Hippocampus .