Herbs For Alzheimer's Disease

by: M. Suresh Gupta and H.N. Shivaprasad

Alzheimer's disease (AD) is a progressive, degenerative brain disease that results in impaired memory, thinking, and behavior. It is the most common cause of dementia, a brain disorder that seriously affects a person's ability to carry out daily activities. At first, the only symptom may be mild forgetfulness, which can be confused with age-related memory change. Most people with mild forgetfulness do not have AD. In the early stage of AD, people may have trouble remembering recent events, activities, or the names of familiar people or things. They may not be able to solve simple math problems. Such difficulties may be a bother, but usually they are not serious enough to cause alarm. AD is a slow disease, starting with mild memory problems and ending with severe brain damage. The course, the disease takes and how fast changes occur vary from person to person. No treatment can stop AD. Some medicines may help control behavioral symptoms of AD such as sleeplessness, agitation, wandering, anxiety, and depression. Treating these symptoms often makes patients more comfortable and makes their care easier for caregivers. Early studies suggested that herbal extracts from the parts of a tree might be of some help in treating AD symptoms. There is no evidence yet that herbal extracts will cure or prevent AD, but scientists now are trying to find out in a clinical trial whether herbal extracts can delay cognitive decline or prevent dementia in older people.

Some vital herbs used in Alzheimer's disease

Ginkgo (Ginkgo biloba)
Ginkgo is widely touted as a "brain herb" and is commonly added to nutrition bars and fruit smoothies to boost memory and enhance cognitive performance. Ginkgo is widely used in Europe for treating dementia. It improves blood flow in the brain. Ginkgo leaves contain two types of chemicals {flavonoids (quercetin) and terpenoids (ginkgolides)} believed to have potent antioxidant properties, improved blood flow properties by dilating the blood vessels. Ginkgo is widely used in Europe for treating dementia. The reason that ginkgo is thought to be helpful for preventing or treating these brain disorders is because it improves blood flow in the brain and because of its antioxidant properties. Ginkgo biloba extract (GBE, 24% flavonoids and 6% terpenoids) is highly concentrated and much more effective in treating health problems (particularly circulatory ailments) than the leaf alone. Recommended dosages for ginkgo range between 120 to 240 mg per day. GBE is considered to be safe and side effects are rare.

Gotu Kola (Centella asiatica )
Gotu Kola popularly called as the "miracle elixirs of life" because an ancient Chinese herbalist lived for more than 200 years as a result of using this particular herb. The widespread belief that Gotu Kola helps improve memory led to several studies on its effect on the central nervous and circulatory systems. Triterpenoids (active compounds in gotu kola) have been shown to soothe anxiety and boost mental function in mice. Gotu Kola extract should contain 40% asiaticoside, 29% to 30% asiatic acid, 29% to 30% madecassic acid, and 1% to 2% madecassoside; doses used in the treatment range from 20 mg (for scleroderma) up to 180 mg (in one study for venous insufficiency). It is available in teas, as dried herbs, tinctures, capsules, tablets, and ointments. It should be stored in a cool, dry place.

Lemon Balm (Melissa officinalis)
Lemon balm, a member of the mint family, has long been considered as a "calming" herb. Lemon balm contains volatile oil, polyphenols, tannins, bitter principle, flavonoids and rosmarinic acid. Many professional herbalists suggest that this herb is beneficial for a variety of health problems including Alzheimer's disease, attention deficit/hyperactivity disorder (ADHD), indigestion, insomnia, and hyperthyroidism. It is available as a dried leaf and sold as tea, and in capsules, extracts, tinctures, and oil.

Rosemary (Rosmarinus officinalis)
The plant takes its name from rosmarinus, a Latin term meaning "sea dew." It is available as dried whole herb, dried, powdered extract (in capsules), tinctures, infusions, liquid extract, and rosemary wine. It contains volatile oil (1-2 %) containing borneol, camphene, camphor, cineole, flavonoids (aspigenin, diosmin), tannins, rosmaric acid, diterpenes (picrosalvin) and rosmaricine. Traditionally, rosemary has been used by herbalists to improve memory, relieve muscle pain and spasm, stimulate hair growth, and support the circulatory and nervous systems. It is also believed to affect the menstrual cycle, act as an abortifacient (inducing miscarriage), relieve menstrual cramps, increase urine flow, and reduce kidney pain (for example, from kidney stones).

Vital Chinese herbs used in Alzheimer's disease

Lycorus radiata (shisuan)
Lycorus radiata contains the alkaloids lycorine, lycoramine, lycoreine, and galanthamine. Both lycoramine and galanthamine have been shown to be reversible cholinesterase inhibitors. Lycoramine is weaker than galanthamine, but equivalent to Nivalin. Galanthamine easily crosses the blood-brain barrier. It decreases cholinesterase activity of the cerebral cortex and medulla oblongata, and at high dosage shows an anticholinesterase activity in the thalamus.

Macleaya cordata (boluohui)
Macleaya cordata contains several alkaloids including sanguinarine, chelerythine, protopine, and allocryptopine. The sulfates of these alkaloids have a more potent local anesthetic action than procaine. Sanguinarine inhibits cholinesterase. The herb is mainly used for bacterial infections and trichomonas, and for killing maggots (the alkaloids cause excitation and then paralysis and death of larvae).

Coptis chinenses (huanglian)
It contains berberine alkaloids, mainly berberine, but also coptisine, worenine, palmatine, and columbamine. Berberine is a cholinesterase inhibitor. Berberine exerts a dose-dependent biphasic effect on acetylcholine in animals and their isolated organs. Berberine antagonizes acetylcholine-induced bradycardia and ST segment depression in rabbits. Tetrahydroberberine, a berberine derivative, produces analgesia, sedation and muscle relaxation, with an effect that is three times more potent than that of meprobamate. Its action may be similar to that of tetrahydropalmatine; l-tetrahydroberberine, like l-tetrahydropalmatine, appears to be a more potent tranquilizer than the d-isomer.

Securinega suffruticosa (yiyiqiu)
It contains many alkaloids, mainly securinine and its derivatives. Securinine is a CNS stimulant that antagonizes the inhibitory action of meprobamate. Securinine inhibits cholinesterase activity, but it is weaker than galantamine. Solanum nigrum, contains solanine, salasodine, and related alkaloids. Solanine markedly decreases spontaneous activity of mice and prolongs the sleeping time induced by pentobarbital. Solanine has a strong anticholinesterase action that is attributed to its aglycone solanidine.

Most of the herbs mentioned in this section inhibit bacterial growth and are used in tumor therapy. The isolated alkaloids often have the same effect as the crude herbs for these applications and are increasingly used in clinical practice. Clearly, there is reason to hope that one or more of the plant alkaloids will prove helpful to those with Alzheimer's and that these alkaloids might be administered with the herbs used by traditional doctors for the treatment of memory disorders so as to attain superior results.

About the Authors:

M. Suresh Gupta is a lecturer in Pharmaceutics at PES College of Pharmacy, Bangalore. He has worked as officer at Analytical R & D in Dr. Reddy's Lab, Hyderabad. He has developed many analytical methods for natural drugs. He also worked as Research Associate at Glenmark Research Centre, Mumbai.

H.N.Shivaprasad is a lecturer in Pharmacognosy & Phytochemistry at PES College of Pharmacy, Bangalore. He has completed his graduation and post-graduation from Rajiv Gandhi University of Health Sciences, India. He is the university rank holder at graduate and postgraduate levels. He has worked as Executive, R & D in Himalaya Drugs, Bangalore. He is doing his Doctoral [Ph.D.] research at Dr. Hari Singh Gour Vishwavidyalaya, Sagar [M.P].
He has several National and International publications to his credit. He has written many health articles in Health and Fitness section of reputed daily Vijay Times. He has also written many scientific articles to reputed herbal websites. He has been awarded as Best presenter in 55th Indian Pharmaceutical Congress, Chennai.
He is the Editor for "Continuing Health Awareness" a fortnightly bulletin which is circulated among all the PES Group of institutions. He is the reviewer for the prestigious PHARMACOGNOSY JOURNAL [www.phcog.net]