Prevention of Ageing-associated Neurodegeneration in Alzheimer’s Disease and Glaucoma with a Wolfberry Extract
A research team in the HKU School of Biomedical Sciences has found that wolfberry not only can protect the retinal ganglion cells on the retina against glaucoma, but also can inhibit neuronal apoptosis to prevent neurodegeneration in Alzheimer’s disease.
Cognitive decline in Alzheimer's disease is one of the ageing-associated neurodegenerative diseases. Neurodegeneration is the major cause in Alzheimer's disease, which is not a normal ageing process. However, there is still no effective therapeutic treatment to cure the disease, let alone medications to prevent it.
About 360,000 new cases are diagnosed with Alzheimer's disease each year in the world and about 190,000 people die each year as a result of the disease. It is estimated that in 2050, there will be 115 million people in the world suffering from Alzheimer's disease. In Hong Kong, currently about 6% of those aged over 70 suffer from Alzheimer’s disease. Twenty years later, one out of every four people in Hong Kong will be over 60 years old.
The clinical symptoms of Alzheimer’s disease include deterioration of memory, and decline of cognitive functions and language functions. Patients might have depression, psychosis, hallucination, behavioral problem, and personality change. Some patients have deterioration of vision.
Chinese wolfberry tastes sweet and has high nutritional value. Traditionally, it is considered as one of the herbs that has the effect of nourishing Yin and is often used in Chinese dishes, soup and desserts. Chinese wolfberry is also used for medicinal purposes in traditional Chinese medicine. It helps nourishing and improving the functions of liver and kidney as well as the visual abilities. It is also prescribed for treatment of diabetes and glaucoma.
Pharmacological effects of Chinese wolfberry:
- Immune modulation and enhancement
- Delay ageing process
- Anti-tumor formation
- Reduce blood lipid to protect liver and anti-nonalcoholic fatty liver
- Reduce blood glucose
- Modulate haematopoiesis
A research team led by Dr Raymond Chuen Chung Chang, Associate Professor in the Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, HKU Li Ka Shing Faculty of Medicine, has been investigating the biological mechanisms of anti-ageing properties of wolfberry and its effects to prevent or even to treat Alzheimer's disease.
In patients with Alzheimer's disease, the prevalence rate of glaucoma is high leading to deterioration of vision. Dr Chang's team has found that wolfberry can protect the retinal ganglion cells on the retina against glaucoma. Wolfberry can also attenuate neuronal apoptosis to prevent progressive deterioration of neurodegeneration in Alzheimer's disease. In the initial stage of neurodegeneration, there is usually an increased level of bad unfolded proteins that can give stress signals to neurons to initiate neuronal apoptosis. The extract from wolfberry can inhibit these signal transductions and stimulate survival/protective signals to keep the survival of neurons.
The cause of Alzheimer's disease is complicated with different risk factors. One of the risk factors is depression. Dr Chang’s team has discovered in laboratory studies that the extract in wolfberry can attenuate depression and may be considered for therapeutic treatment against depression.
The team will conduct further research to verify that the anti-ageing Chinese medicine, which can mildly boost up immunity in the body, can also protect neurons against neurodegeneration in Alzheimer’s disease.