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This study explores the potential of Isorhynchophylline (IRN) in improving cognitive deficits caused by aluminum chloride in mice. IRN showed neuroprotective, antioxidant, and cholinergic inhibitory effects, suggesting its potential as a therapeutic agent for Alzheimer's disease.
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Isorhynchophylline Improves Learning and Memory Impairments Induced by Aluminum Chloride in Mice Zhi-Xiu Lin, Ph.D. Acting Director and Associate Professor, School of Chinese Medicine, The Chinese University of Hong Kong ; Registered Chinese Medicine Practitioner, Hong Kong. 2nd World Congress on Molecular Genetics & Gene Therapy, Bangkok, Thailand, 3-4 July 2017
Alzheimer’s Disease (AD) AD is the most common form of dementia in elderly. Symptoms: Memory loss, language deficit, depression, agitation and anxiety, death from opportunistic infections, etc. • Epidemiology: • More than34 million people currently affected by AD. • Over 114 million by 2050. • The cost of caring for people with AD is about $ 200 billion every year in the United States.
Pathogenesis of AD Normal Brain Mild AD’s Brain Moderate AD’S Brain Severe AD’s Brain
Cholinesterase inhibitors(AChEIs): donepezil, rivastigmine, galantamine. N-methyl-D-aspartate(NMDA) glutamate receptor antagonists: memantine. Problems: • Temporary and modest improvement,without long-term beneficialeffect inthe disease. • Various side effects. Current treatments for AD Therefore, searching for safer, better-tolerated, and more effective drugs for the treatment of AD remains an important area of drug discovery.
Isorhynchophylline (IRN) Uncaria rhynchophylla (鉤藤) Active ingredient Biological activities Neuroprotective Analgesic Anti-inflammatory Anti-oxidant Anti-hypertensive Inhibition of AChE
Hypothesis IRN Hypothesis: Isorhynchophylline (IRN) may have potent protective effects in other animal model of AD.
Experimental design and schedule Explore the maze freely Test and record data Subcutaneous AlCl3 injection Training 1 5 10 20 30 40 56 57 58 59 60 61 62 63 64 65 Days Drug treatment
Radial Eight-Arm Maze (RAM) Food Food Food Food
Effects of IRN on cognitive deficits induced by AlCl3 in mice A B C Fig. 1. Effects of IRN on spatial memory of mice as evaluated by the RAM test after 7 days of training. The total entrance to complete the task (A), the reference memory errors (B), and the working memory errors (C). Data were expressed as mean ± SEMs; n=6-10;
Effects of IRN on oxidative stress induced by AlCl3 in the brain of mice
Effects of IRN on oxidative stress induced by AlCl3 in the brain of mice
Effects of IRN on the cholinergic system in the brain of AlCl3-treated mice
Effects of IRN on NFĸB pathway in the brain of AlCl3-treated mice p p-p65 p65 p-IĸBα IĸBα β-actin 20 40 Control 5 (mg/kg) IRN Donepezil AlCl3
Antioxidant mediators Levels of MDA, GSH Activities of SOD, CAT Summary • IRN was able to ameliorate cognitive deficits induced by AlCl3 in mice. • IRN could inhibit the AChE activity and enhance the antioxidant status of brain tissue. • IRN could suppress the NF-ĸB pathway in the brain of mice. + Mouse AlCl3 Induces Enhances Ameliorates Cognitive deficits Suppresses NF-ĸB pathway IRNtreatment 18
Future Work • To delineate the molecular mechanisms and pathways associated with neuroprotective effect of IRN in the primary culture of rat hippocampal neurons. (on-going) • To further confirm the ameliorating cognitive deficits effects of IRN using TgCRND8 transgenic mouse model of AD. (on-going) • To delineate the pharmacokinetics of IRN in normal and AD animals.
U. Rynchophylla-containing Formula - CogniMax 钩藤 红景天 肉苁蓉 白黎芦醇
Acknowledgements • Dr. Yan-Fang Xian • Dr. Siu-Po Ip Ms. Huiqin Li • Dr. Chun-Yuan Zhang All colleagues in SCM. Fundings: • General Research Fund from Research Grants Council of Hong Kong (project no. 14110814) • CUHK Direct Grant (project no. 2015.1.081)