The positive effect of levodopa in the treatment of Parkinson’s disease,although it is limited in time and has severe side effects,has encouraged the scientific community to look for new drugs that can stop the neuro...The positive effect of levodopa in the treatment of Parkinson’s disease,although it is limited in time and has severe side effects,has encouraged the scientific community to look for new drugs that can stop the neurodegenerative process or even regenerate the neuromelanin-containing dopaminergic nigrostriatal neurons.Successful preclinical studies with coenzyme Q10,mitoquinone,isradipine,nilotinib,TCH346,neurturin,zonisamide,deferiprone,prasinezumab,and cinpanemab prompted clinical trials.However,these failed and after more than 50 years levodopa continues to be the key drug in the treatment of the disease,despite its severe side effects after 4–6 years of chronic treatment.The lack of translated successful results obtained in preclinical investigations based on the use of neurotoxins that do not exist in the human body as new drugs for Parkinson’s disease treatment is a big problem.In our opinion,the cause of these failures lies in the experimental animal models involving neurotoxins that do not exist in the human body,such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine,that induce a very fast,massive and expansive neurodegenerative process,which contrasts with the extremely slow one of neuromelanin-containing dopaminergic neurons.The exceedingly slow progress of the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson’s patients is due to(i)a degenerative model in which the neurotoxic effect of an endogenous neurotoxin affects a single neuron,(ii)a neurotoxic event that is not expansive and(iii)the fact that the neurotoxin that triggers the neurodegenerative process is produced inside the neuromelanin-containing dopaminergic neurons.The endogenous neurotoxin that fits this degenerative model involving one single neuron at a time is aminochrome,since it(i)is generated within neuromelanin-containing dopaminergic neurons,(ii)does not cause an expansive neurotoxic effect and(iii)triggers all the mechanisms involved in the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson’s disease.In conclusion,based on the hypothesis that the neurodegenerative process of idiopathic Parkinson’s disease corresponds to a single-neuron neurodegeneration model,we must search for molecules that increase the expression of the neuroprotective enzymes DT-diaphorase and glutathione transferase M2-2.It has been observed that the activation of the Kelch-like ECH-associated protein 1/nuclear factor(erythroid-derived 2)-like 2 pathway is associated with the transcriptional activation of the DT-diaphorase and glutathione transferase genes.展开更多
Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis m...Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.展开更多
文摘The positive effect of levodopa in the treatment of Parkinson’s disease,although it is limited in time and has severe side effects,has encouraged the scientific community to look for new drugs that can stop the neurodegenerative process or even regenerate the neuromelanin-containing dopaminergic nigrostriatal neurons.Successful preclinical studies with coenzyme Q10,mitoquinone,isradipine,nilotinib,TCH346,neurturin,zonisamide,deferiprone,prasinezumab,and cinpanemab prompted clinical trials.However,these failed and after more than 50 years levodopa continues to be the key drug in the treatment of the disease,despite its severe side effects after 4–6 years of chronic treatment.The lack of translated successful results obtained in preclinical investigations based on the use of neurotoxins that do not exist in the human body as new drugs for Parkinson’s disease treatment is a big problem.In our opinion,the cause of these failures lies in the experimental animal models involving neurotoxins that do not exist in the human body,such as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine,that induce a very fast,massive and expansive neurodegenerative process,which contrasts with the extremely slow one of neuromelanin-containing dopaminergic neurons.The exceedingly slow progress of the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson’s patients is due to(i)a degenerative model in which the neurotoxic effect of an endogenous neurotoxin affects a single neuron,(ii)a neurotoxic event that is not expansive and(iii)the fact that the neurotoxin that triggers the neurodegenerative process is produced inside the neuromelanin-containing dopaminergic neurons.The endogenous neurotoxin that fits this degenerative model involving one single neuron at a time is aminochrome,since it(i)is generated within neuromelanin-containing dopaminergic neurons,(ii)does not cause an expansive neurotoxic effect and(iii)triggers all the mechanisms involved in the neurodegenerative process of the nigrostriatal neurons in idiopathic Parkinson’s disease.In conclusion,based on the hypothesis that the neurodegenerative process of idiopathic Parkinson’s disease corresponds to a single-neuron neurodegeneration model,we must search for molecules that increase the expression of the neuroprotective enzymes DT-diaphorase and glutathione transferase M2-2.It has been observed that the activation of the Kelch-like ECH-associated protein 1/nuclear factor(erythroid-derived 2)-like 2 pathway is associated with the transcriptional activation of the DT-diaphorase and glutathione transferase genes.
基金Supported by The Tackling-plan Project of Henan Department of Science and Technology (222102310388)Key Scientific Research Plan of Colleges in Henan Province (22B350002)Henan Provincial Medical Science and Technology Research Plan Joint Construction Project (LHGJ20191520).
文摘Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.
