RESUMO
Alzheimer’s disease (AD) is a central neurodegenerative disease characterized by progressive cognitive dysfunction and behavioral impairment, and there is a lack of effective drugs to treat AD clinically. Existing medications for the treatment of AD, such as Tacrine, Donepezil, Rivastigmine, and Aducanumab, only serve to delay symptoms and but not cure disease. To add insult to injury, these medications are associated with very serious adverse effects. Therefore, it is urgent to explore effective therapeutic drugs for AD. Recently, studies have shown that a variety of enzyme inhibitors, such as cholinesterase inhibitors, monoamine oxidase (MAO)inhibitors, secretase inhibitors, can ameliorate cholinergic system dysfunction, Aβ production and deposition, Tau protein hyperphosphorylation, oxidative stress damage, and the decline of synaptic plasticity, thereby improving AD symptoms and cognitive function. Some plant extracts from natural sources, such as Umbelliferone, Aaptamine, Medha Plus, have the ability to inhibit cholinesterase activity and act to improve learning and cognition. Isochromanone derivatives incorporating the donepezil pharmacophore bind to the catalytic active site (CAS) and peripheral anionic site (PAS) sites of acetylcholinesterase (AChE), which can inhibit AChE activity and ameliorate cholinergic system disorders. A compound called Rosmarinic acid which is found in the Lamiaceae can inhibit monoamine oxidase, increase monoamine levels in the brain, and reduce Aβ deposition. Compounds obtained by hybridization of coumarin derivatives and hydroxypyridinones can inhibit MAO-B activity and attenuate oxidative stress damage. Quinoline derivatives which inhibit the activation of AChE and MAO-B can reduce Aβ burden and promote learning and memory of mice. The compound derived from the combination of propargyl and tacrine retains the inhibitory capacity of tacrine towards cholinesterase, and also inhibits the activity of MAO by binding to the FAD cofactor of monoamine oxidase. A series of hybrids, obtained by an amide linker of chromone in combine with the benzylpiperidine moieties of donepezil, have a favorable safety profile of both cholinesterase and monoamine oxidase inhibitory activity. Single domain antibodies (such as AAV-VHH) targeted the inhibition of BACE1 can reduce Aβ production and deposition as well as the levels of inflammatory cells, which ultimately improve synaptic plasticity. 3-O-trans-p-coumaroyl maslinic acid from the extract of Ligustrum lucidum can specifically inhibit the activity of γ-secretase, thereby rescuing the long-term potentiation and enhancing synaptic plasticity in APP/PS1 mice. Inhibiting γ-secretase activity which leads to the decline of inflammatory factors (such as IFN-γ, IL-8) not only directly improves the pathology of AD, but also reduces Aβ production. Melatonin reduces the transcriptional expression of GSK-3β mRNA, thereby decreasing the levels of GSK-3β and reducing the phosphorylation induced by GSK-3β. Hydrogen sulfide can inhibitGSK-3β activity via sulfhydration of the Cys218 site of GSK-3β, resulting in the suppression of Tau protein hyperphosphorylation, which ameliorate the motor deficits and cognitive impairment in mice with AD. This article reviews enzyme inhibitors and conformational optimization of enzyme inhibitors targeting the regulation of cholinesterase, monoamine oxidase, secretase, and GSK-3β. We are hoping to provide a comprehensive overview of drug development in the enzyme inhibitors, which may be useful in treating AD.
RESUMO
Background and Aim: With the increasing burden of colorectal cancer (CRC), the practice of colonoscopy is gaining attention worldwide. However, it exhibits distinct trends between developing and developed countries. This study aims to explore its development and identify influencing factors in China. Methods: The Chinese Digestive Endoscopy Censuses were conducted twice in mainland China under the supervision of health authorities. Information regarding the practice of colonoscopy was collected through a structured online questionnaire. The authenticity of the data was evaluated through logical tests, and a random selection of endoscopic reports underwent manual validation by Quality Control Centers. Potential factors associated with colonoscopy were analyzed using real-world information. Results: From 2012 to 2019, the number of hospitals that performed colonoscopy increased from 3,210 to 6,325 (1.97-fold), and the volume increased from 5.83 to 12.92 million (2.21-fold). The utilization rate rose from 436.0 to 914.8 per 100,000 inhabitants (2.10-fold). However, there was an exacerbation of regional inequality in the adequacy of colonoscopy. Regions with higher incidence of CRC, higher gross domestic product per capita, more average numbers of endoscopists and tertiary hospitals tended to provide more accessible colonoscopy (P<0.001). Nationwide, the cecal intubation rate improved from 83.9% to 94.4% and the unadjusted adenoma detection rate (ADR) improved from 16.3% to 18.1%. Overall, hospital grading, educational background of endoscopists, economic income, and colonoscopy volume were observed as the significantly positive factors affecting ADR (P<0.05), but not the incidence of CRC or the number of endoscopists. Conclusions: Tremendous progress in colonoscopy has been made in China, but some issues needed timely reflection. Our findings provide timely evidence for better colonoscopy strategies and measures, such as quality control and medical education of endoscopists.