Medicinal plants with a potential to treat Alzheimer and associated symptoms

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Alzheimer's disease (AD) is a progressive neurological disease of the brain named after German physician Aloes Alzheimer, who first described it in 1906. Alzheimer's is the most common form of dementia and affects an estimated 10 million people worldwide. The most common form of dementia is AD, which demolishes the vital brain cells, causing trouble with memory, thinking, and behavior, brutal enough to affect work, lifelong hobbies, and social life. Recognized factors in Alzheimer's disease include acetylcholine deficiency, free radicals, and inflammation of the brain tissue. Many of the current drugs taken to treat the disease, such as, donepezil, have unpleasant side effects and doctors are keen to find alternatives. There is no cure for Alzheimer's disease, but drugs designed to slow disease progression are available. Some herbs may help to improve brain function, but scientific evidence to prove that they can treat Alzheimer's disease, is limited. Electronic database like MEDLINE, LILACS, Cochrane Library, dissertation Abstract (USA), National Research Register, Current Controlled trials, Centerwatch Trials Database, and PsychINFO Journal Article bases were used to search for information related to studies done on plants in the past years. The objective here is to provide a systematic review of the ongoing evidence pertaining to the use of medicinal herbs in the treatment of Alzheimer's disease (AD) and its associated symptoms.

Introduction

Alzheimer's disease (AD) is a brain disorder named after German physician Aloes Alzheimer, who first described it in 1906. Alzheimer's disease is a progressive and neurodegenerative disease that primarily affects the elderly population of over 65 years of age, and is estimated to account for 50 - 60% of the dementia cases. [1] The prevalence has been found to rise exponentially with age, ranging from 3.0% in patients aged 65 to 74 years to as much as 47.2% in those aged 85 years. [2],[3] This condition is characterized by a progressive loss of memory, deterioration of virtually all intellectual functions, increased apathy, decreased speech function, disorientation, and gait irregularities.

Electronic databases like MEDLINE, LILACS, Cochrane Library, dissertation Abstract (USA), National Research Register, Current Controlled trials, Centerwatch Trials Database, and PsychINFO Journal Articles bases were used to search for information related to studies done on plants in the past years. The search combined the terms Alzheimer disease, dementia, cognition disorders, Herbal, and Phytotherapy.

The brain has 100 billion nerve cells (neurons). Each nerve cell connects with many others to form communication networks. Groups of nerve cells have special jobs. Some are involved in thinking, learning, and remembering. Others help us see, hear, and smell. To do their work, brain cells operate like tiny factories. They receive supplies, generate energy, construct equipment, and get rid of waste. Cells also process and store information and communicate with other cells. Keeping everything running requires coordination as well as large amounts of fuel and oxygen.

The beta-amyloid peptide, with 39 - 42 amino acid residues (BAP), plays a significant role in the development of AD. Although there is no cure for AD, it can be managed with the available drugs, to some degree. Several studies have revealed that natural antioxidants, such as vitamin E, vitamin C, and beta-carotene, may help in scavenging free radicals generated during the initiation and progression of this disease. The loss of memory is considered to be the result of a shortage of the nerve transmitter acetylcholine. It is possible to increase the level of this transmitter in the brain by inhibiting the activity of the enzyme acetylcholinesterase, which splits or breaks down the transmitter substance. Drugs that inhibit the breakdown of the messenger or transmitter acetylcholine delay the development of the disease. [4]

Alzheimer's is the most common form of dementia.

Other Types of Dementia

Alzheimer's disease accounts for 50 to 70% of the cases of dementia. Other disorders that can cause memory loss, confusion, and other symptoms associated with dementia include:

Vascular dementia, often considered the second most common type of dementia, refers to impairment caused by reduced blood flow to parts of the brain. One type may develop after a single major stroke blocks blood flow to a large area of brain tissue. Another kind, formerly called 'multi-infarct dementia,' can occur when a series of very small strokes clog tiny arteries. Individually, these strokes are too minor to cause significant symptoms, but over time their combined effect becomes noticeable. Symptoms of vascular dementia can be similar to Alzheimer's disease. They include problems with memory, confusion, and difficulty following instructions. In some cases, the impairment associated with vascular dementia can occur in 'steps' rather than in a slow, steady decline, usually seen in Alzheimer's.

Mixed dementia is a condition in which Alzheimer's disease and vascular dementia occur together. Some experts believe that this combination is also very common. There is some evidence to show that this type of dementia is much more common than once believed.

Parkinson's disease affects the control of movement, resulting in tremors, stiffness, and impaired speech. Many individuals with Parkinson's also develop dementia at a later stage of the disease.

Dementia with Lewy bodies often starts with wide variations in attention and alertness. Individuals affected by this illness often experience visual hallucinations as well as muscle rigidity and tremors similar to those associated with Parkinson's disease.

Physical injury to the brain caused by an automobile accident or other trauma can damage or destroy brain cells and cause symptoms of dementia, such as, behavioral changes, memory loss, and other cognitive difficulties.

Huntington's disease is an inherited, progressive disorder that causes irregular movements of the arms, legs, and facial muscles; personality changes; and a decline in the ability to think clearly.

 Creutzfeldt-Jakob disease ^{More Details} (CJD) (CROYZ-felt YAH- kob) is a rare, rapidly fatal disorder that impairs memory and coordination and causes behavior changes. Of late, 'variant Creutzfeldt-Jakob disease' (vCJD) was identified as the human disorder believed to be caused by eating meat from cattle affected by 'mad cow disease.'

Frontotemporal dementia or Pick's disease is another rare disorder that may sometimes be difficult to distinguish from Alzheimer's. Personality changes and disorientation often occur before memory loss.

Normal pressure hydrocephalus (NPH) is caused by a buildup of fluid in the brain. The cause of most cases is unknown. Symptoms include difficulty walking, memory loss, and inability to control urine. NPH can sometimes be corrected with surgery to drain the excess brain fluid. ^[5]

Causes and Risk Factor

The causes of Alzheimer's disease is being investigated in a number of areas. Already, several genes have been linked to the development of Alzheimer's. Even as genetic factors may increase the likelihood that a person will develop Alzheimer's, environmental factors are believed to have an important role as well. On the other hand also, a number of environmental factors are found that have been associated with the development of Alzheimer's, including long-term exposure to silicon or aluminium, ^[6] chronic exposure to other toxins, free-radical damage, ^[7] and traumatic head injury.

The dysregulation of biometal (Cu, Zn, Fe) homeostasis and oxidative stress in the brain cells are major hallmarks in the pathogenesis of Alzheimer's disease (AD). ^[8] During the 1960s and 1970s, aluminum emerged as a possible suspect in causing Alzheimer's disease. This suspicion led to concerns about everyday exposure to aluminum through sources such as cooking pots, foil, beverage cans, antacids, and antiperspirants. Since then, studies have failed to confirm any role for aluminum in causing Alzheimer's, but few experts believe that continuous exposure to aluminum source may cause threat. According to a growing body of evidence, risk factors for vascular disease — including diabetes, high blood pressure, and high cholesterol — may also be risk factors for Alzheimer's and stroke-related dementia.^[5]

Signs and Symptoms

Memory impairment is the hallmark symptom of Alzheimer's disease and usually involves behaviors such as forgotten appointments, away from home, misplaced items, and repetitive questions. Along with memory problems, AD can be recognized by insomnia, anxiety, depression, disruptive behavior, and hallucinations. Several studies have found evidence that Alzheimer's disease is a disease that is caused by or is a result of decreased metabolic activity in the brain.

Alzheimer's disease has been classified into three stages and each stage has its specific symptoms.

Stage One usually lasts two to four years. It involves confusion, forgetfulness, disorientation, recent memory loss, and mood changes.

Stage Two often lasts two to ten years. It is typically characterized by decreased memory reduced attention span, hallucinations, restlessness, muscle spasms, reduced to perform logic, increased irritability, and increased inability to organize thoughts.

Stage Three generally lasts one to three years with risk factors that include age, head injury, and most often involve incontinence, swallowing difficulty, the development of skin infections, and seizures. ^[9]

Diagnosis

It is very important to get an early and accurate diagnosis of Alzheimer's disease in order to effectively treat it as early as possible. These herbal treatments should begin (along with regular brain exercises) immediately after diagnosis to maximize the potential of leading a normal and healthy life.

Alzheimer's disease can be reliably diagnosed with a complete examination that includes the following tests:

• A complete medical and psychiatric history
• A neurological examination
• Laboratory tests to rule out anemia, vitamin deficiencies, and other conditions
• A mental status examination to evaluate the person's thinking and memory
• Talking with family members or caregivers
  • Mental Status Examination Diagnostic tests for Alzheimer's Disease: One of the key diagnostic tests for dementias such as Alzheimer's is the Mental Status Examination (MSE).
  • The Mini-Cog test takes about three minutes to administer and is often used in Emergency Departments, for people who appear to have some type of dementia like Alzheimer's disease.
  • Urinalysis Urine test:
  • Routine analysis of urine is just one of the tests that your doctor will do if Alzheimer's disease or another type of dementia is suspected. Urinalysis (urine tests) screens for abnormalities. Urinalysis can detect a number of diseases or conditions where symptoms may be similar to dementias such as severe renal disease.
  • Mild Cognitive Impairment (MCI)
  • People may sometimes fear the onset of dementia, whereas, they will be experiencing mild cognitive impairment.
  • Visual Clues to Dementia Diagnosis
  • There are a number of strong visual clues that can indicate that someone may be suffering from a dementia such as Alzheimer's disease. Appearance, dress, and personal hygiene may deteriorate. Visual clues are important, but provide only one aspect of human behavior and presentation that may lead to diagnosis.
  • Lumbar Puncture test
  • Although uncommon in tests of dementia the lumbar puncture can reveal rare diseases that can mimic the signs of dementia
  • The Mini Mental State Examination (MMSE) is most commonly used to test for memory problems and contributes to a possible diagnosis of dementia. ^[10]
  • The electroencephalogram (EEG) is a useful tool in the diagnosis of Alzheimer's. Those with the disease have a diffuse and symmetrical slowing of the brain waves that register on the EEG. ^[9]

Medicinal Herbs to Treat Alzheimer

A number of scientific researches have been carried out on medicinal herbs. Herbs have anti-inflammatory and antioxidant activities that may be used in the treatment of AD. Alzheimer's patients have an acetylcholine deficiency. Anti-inflammatory herbs may reduce inflammation of the brain tissue in Alzheimer's: German chamomile, Ginseng, licorice, turmeric, and white willow bark. Acetylcholine is a neurotransmitter that plays a key role in cognitive function and reasoning. The brains of those with mild-to-moderate Alzheimer's disease, a progressive type of dementia, have abnormally low acetylcholine concentrations. This means that any compound that enhances the cholinergic system in the brain may be useful in treating Alzheimer's disease and similar brain malfunctions. The herbs that inhibit Acetylcholinesterase (AchE) contain natural COX-2 inhibitors, also reported as medicinal herbs, for AD indication.

Some ayurvedic herbs like Guduchi, Yashtimadhuk, Padma (Nelumbo nucifera), Vacha, Convolvulus pluricaulis, Shankhpushpi, Pancha-Tikta-Ghruta Gugguli, Amalaki, Musta Arjun, Amalaki, Ashwagandha, Galo Satva, Kutaj, and others are excellent herbs for slowing down the brain cell degeneration caused by Alzheimer's. They enhance the brain's ability to function, and therefore, provide stability when used consistently.

Curcuma longa L. (Zingiberaceae)

Curcuma longa (Turmeric, Harida) has been used as a source of Curcumin (diferuloylmethane), an orange-yellow component of turmeric or curry powder. Studies have proved that Curcumin has anti-inflammatory and antioxidant activities, and it helps in combating Alzheimer's Disease (AD). Regular consumption of this herb helps in keeping the mind balanced. ^[11] The dose of curcumin can be reduced by making it to colon targeting. ^[12]

Bacopa monniera Wettst. (Scrophulariaceae)

Goswami et al., evaluate the effect of Bacopa monnieri (Brahmi), associated with the Ayurveda system of medicine, on the cognitive functions in Alzheimer's disease patients, and conclude that it could be beneficial in these patients, but more study is needed. ^[13]

Centella asiatica L. (Umbelliferae)

Extract from the leaves of Gotu Kola (Centella asiatica) has been used as an alternative medicine for memory improvement in the Indian Ayurvedic system of medicine for a long time.

Ginkgo biloba L. (Ginkgoaceae)

Ginkgo Biloba is the best known herb for Alzheimer's disease and its associated symptoms. In controlled clinical trials, using a placebo and control group, ginkgo biloba extracts showed therapeutic benefits in Alzheimer's, similar to prescription drugs such as Donepezil or Tactrin, with minimal undesirable side effects. ^[14] The chief chemical constituent of gingko biloba is gingkolides and it is a pertinent antioxidant, with neuroprotective and cholinergic activities that help in the management of AD. Ginkgo biloba improves protection against Aβ protein-induced oxidative damages (degrading hydrogen peroxide, preventing lipids from oxidation, and trapping the reactive oxygen species). ^[15]

Ginkgo Biloba is best known for its ability to enhance circulation systemically. Its action is directly related to the vasorelaxing activity. Thus, Ginkgo Biloba can lower blood pressure and inhibit platelet aggregation. Scientific studies have shown its promise on cognition-enhancement (booster), if used during the early stages of Alzheimer's disease.

Salvia officinalis (Lamiaceae)

Sage as it is more commonly referred for Alzheimer's disease treatment. It has been reported to assist the brain in the fight against AD. Sage contains the antioxidants carnosic acid and rosmarinic acid. These compounds are thought to protect the brain from oxidative damage. ^[16]

Rosmarinus officinalis (Lamiaceae)

Rosemary (Satapatrika) contains the following natural COX-2 inhibitors: Apigenin, carvacrol, eugenol, oleanolic acid, thymol, and ursolic acid. 'If a synthetic COX-2 inhibitor could prevent Alzheimer's disease, so could a natural COX-2 inhibitor,' according to Duke 2007. In addition, Rosemary contains nearly two dozen antioxidants and another dozen anti-inflammatory compounds. Some of the strongest antioxidant substances in the herb are carnosic acid and ferulic acid, which have even greater reported antioxidant activity than the widely common synthetic antioxidants butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). ^[17] Rosemary can be used as a tea, in shampoo, or in bath water, because it can be absorbed through the skin. ^[18]

Matricaria recutita (Asteraceae)

German Chamomile is said to stimulate the brain, dispel weariness, calm the nerves, counteract insomnia, aid in digestion, break up mucus in the throat and lungs, and aid the immune system. Chamomile can relieve anxiety, and in higher doses, leads to drowsiness, according to the University of Maryland Medical Center. ^[19]

Melissa officinalis L. (Lamiaceae)

Historically, Melissa officinalis (lemon balm) was believed to sharpen memory. Lemon balm can also temporarily improve cognitive decline as well as improve the mood for Alzheimer's patients. Another study addressing the use of lemon balm for Alzheimer's Disease, concluded that Melissa officinalis is one of several plants that may be useful in the prevention and treatment of Alzheimer's disease due to its ability to inhibit acetylcholinesterase and its antioxidant activity. ^[19],[20]

Glycyrrhiza glabra (Fabaceae)

Alzheimer's disease is characterized by neuronal loss and the presence of extracellular senile plaques, whose major constituent is amyloid-β peptide (Aβ). In this study, we investigated the effects of a water extract of licorice (Yashti-madhuka) on Aβ25-35-induced apoptosis in PC12 cells. Results suggest that GWE exerts a protective effect against apoptotic neuronal cell death induced by Aβ fragments. Extract from the licorice root is reported to treat or even prevent brain cell death in diseases like Alzheimer's and its associated symptoms. ^[21]

Galanthus nivalis L. (Amaryllidaceae)

The chief chemical constituent of the Galanthus nivalis L. (common snowdrop) is Galanthamine, and this is an isoquinoline alkaloid. Acetylcholinesterase (AChE) inhibitors, which are also called 'anticholinesterase drugs', have been recently approved as an promising treatment approach for AD. Galanthamine has been found to be the long-acting and specific inhibitor of the AChE enzyme and to potentiate cholinergic nicotinic neurotransmission by allosterically modulating the nicotinic acetylcholine receptors, which may be of additional value in the treatment of AD. ^[22],[23]

Huperzia serrata (Lycopodiaceae)

Huperzia serrata (Thunb. ex Murray) is one of the genera in the Huperziaceae family (syn. Lycopodiaceae family). This genus, has been used for its memory-enhancing effect since ages in the Traditional Chinese Medicinal system (TCM), and is known to contain a large group of alkaloids called 'Lycopodium alkaloids'. Huperzine A, a novel Lycopodium alkaloid extracted from Huperzia serrata, is well known as a reversible, potent, and selective AChE inhibitor. It is also known as 'Qian Ceng Ta' in China, and Huperzine A has been used as a therapeutic agent for AD from centuries. ^[24]

As reported by researchers, taking Huperzine-A leads to a significant improvement in memory, concentration, and the learning capacity. Research has also shown that Huperzine-A substantially reduces the abnormally high radical activity both in the brains of elderly animals as well as in the blood of Alzheimer's patients. An experimental study in monkeys has shown that it reverses scopolamine-induced amnesia, suggesting that it may benefit the cognitive problems in Alzheimer's patients or those with other cognitive disorders. ^[25]

Commiphora whighitti (Burseraceae)

Commiphora whighitti (Guggulu), a plant resin, contains the major constituent of guggulipid, which is guggulsterone. The guggulipid has been seen to be a potential cognitive enhancer for improvement of memory in scopolamine-induced memory deficits. ^[26]

Commiphora whighitti acts on impairment in learning and memory and decreased choline actyl transferase levels in hippocampus. However, Commiphora whighitti shows maximum effects on memory functions and the potential for dementia disorder. ^[27]

Lipidium Meyenii Walp (Brassicaceae)

Lipidium Meyenii (maca), is known as Maca. Maca shows beneficial improvement in memory and learning. Black maca improves experimental memory impairment, induced by ovariectomy, due in part, to its antioxidant and AChE inhibitory activities. Results demonstrated that black maca can enhance learning and memory in OVX (ovariectomized) mice and this effect might be related, at least in part, to its ability to reduce LPO (Lipid peroxidation) and AChE in OVX mice. ^[28]

Panax Ginseng (Araliaceae)

Panax Ginseng (Ren-shen) contains saponins protopanaxadiol, protopantriol, and oleanolic acid saponins that are reported to have memory-enhancing action for the learning impairment induced by scopolamine. ^[26] Ginseng grows in Northeastern Asia. The Ginseng root has been used in folk medicine in countries like China and Korea, for boosting Qi (energy), from ancient time. Ginseng has a history of medicinal use that goes back thousands of years. The ginseng extract has many uses, and claim to achieve and maintain both physical health and mental well-being. ^[29]

Research has also suggested that ginseng is able to enhance the psychomotor and cognitive performance, and can benefit AD by improving the brain cholinergic function, reducing the level of AD, and repairing the damaged neuronal networks. ^[19]

Acorus calamus L. (Araceae)

Acorus Calamus (Sweet flag)) (Araceae) possesses a beneficial memory enhancing property for memory impairment, learning performance, and behavior modification. Acorus Calamus inhibits the acetylcholinesterase (AChE). Acorus Calamus contains a majority of α-and β-asarone. ^[26] In the Ayurveda medicine system, Acorous Calamus has been used for the treatment of memory loss and its related symptoms. Acorus Calamus also shows anti-inflammatory, antioxidant, antispasmodic, cardiovascular hypolipidemic, immunosuppressive, cytoprotective, antidiarrheal, antimicrobial, and anthelmintic activities.

Angelica archangelica L.(umbelliferae)

Angelica archangelica L ., also known as Dudhachoraa (Laghu Coraka), contains several substances that have the same kind of activity as drugs used for Alzheimer's disease. These substances do not cause the side effects observed with drugs, such as, nausea, stomach ache, insomnia, and so on. The same phytochemicals in Angelica archangelica can also increase blood flow in the brain. A study shows that chloromethane sub-fraction of a methanol extract inhibit AChE in-vitro. ^[30],[31]

Tinospora cordifolia (Menispermaceae)

Tinospora Cordifolia (Guduchi) possesses a memory enhancing property for learning and memory in normal and memory-deficits animals. Tinospora Cordifolia's mechanism for cognitive enhancement is by immunostimulation and synthesis of acetylcholine, this supplementation of choline enhances the cognitive function. ^[26]

Magnolia officinalis (Magnoliaceae)

The bark of Magnolia Officinalis (talauma) is used as a traditional memory enhancing agent in Chinese medicine for the treatment of neurosis, anxiety, stroke, and dementia. Magnolia Officinalis inhibits the memory impairment induced by scopolamine through the inhibition of AChE. The ethanolic extracts of M. officinalis, magnolol and honokiol, are reported to have antioxidant activity in vitro and in vivo. ^[26],[31]

Collinsonia canadensis (Lamiaceae)

Horsebalm (Monarda) has been reported to prevent the breakdown of acetylcholine. The chief chemical constituents of horsebalm are carvacol and thymol which are used for AD. Normally our body's protective blood-brain barrier helps prevent harmful substances in the blood from reaching the tissues of the brain. However, it can also prevent helpful medicines from reaching the brain. The horsebalm compounds seem to cross that great divide. Horsebalm is even used as a herbal shampoo by adding a few drops to your normal herbal shampoo. ^[18]

Bertholettia excelsa (Lecythidaceae)

Although the name is Brazil Nuts, the most significant exporter of Brazil nuts is not Brazil, but Bolivia. In Brazil these nuts are called castanhas-do-Para. ^[32] It has a high concentration of lecithin, which contains choline. Choline is a building block for acethycholine. These building blocks enhance the concentration of acethylcholine in AD patients. Other plants that contain good amounts of lecithin are dandelion flowers, poppy seeds, soybeans, mung beans, horehound, ginseng, cowpeas, English peas, and lentils. ^[18]

Urtica dioica L. (Clusiaceae)

Stinging Nettle has been used for centuries to treat allergy symptoms, particularly hayfever, which is the most common allergy problem. It contains biologically active compounds that reduce inflammation. It contains the mineral boron that is reported to enhance the levels of estrogen, which is a hormone in the body, which can be beneficial in short-term memory. Stinging nettle has also been shown to elevate the mood in some Alzheimer's patients. ^[18],[32]

Withania somnifera (Solanaceae)

Active glycowithanolides of Withania somnifera (Ashawgandha) have a significant antioxidant function, which is accomplished by increasing the activities of superoxide dismutase, catalase, and glutathione peroxidase. ^[33] Ashwagandha is also reported as a Nervine tonic that rejuvenates the cells and boosts energy.

The assessment of cholinesterase inhibition was carried out using a colorimetric method based on Ellman's reaction and demonstrated that the W. Somnifera extract significantly inhibited AChE in a concentration-dependent manner. ^[34]

The most common medicinal herbs for the treatment of AD and those reported in literature are Ginkgo biloba L. (Ginkgoceae), Salvia officinalis L., and Huperzia serrata Thunb. (Lycopodiaceae). Some others are medicinal herbs that have a beneficial effect in the reatment of Alzheimer's disease (AD) and its associated symptoms are: Acorus calamus L. (Araceae), Angelica archangelica L. (Umbelliferae), Bacopa monniera Wettst. (Scrophulariaceae), Biota orientalis L. (Coniferae) Cupressaceae, Celastrus paniculatus Willd. (Celastraceae), Centella asiatica L. (Umbelliferae), Clitoria ternatea L. (Leguminosae), Codonopsis pilosula Franch. (Campanulaceae), Convolvulus pluricaulis Chois. (Convolvulaceae), Coptis chinensis Franch. (Ranunculaceae), Crocus sativus L. (Iridaceae), Curcuma longa L. (Zingeberaceae), Evodia rutaecarpa (Juss.) Benth. (Rutaceae), Ginkgo biloba L. (Ginkgoaceae), Hypericum perforatum L. (Clusiaceae) (Hypericaceae) Magnolia officinalis Rehd. and Wils. (Magnoliaceae), Melissa officinalis L. (Lamiaceae), Piper methysticum Frost. (Piperaceae), Polygala tenuifolia Wild. (Polygalaceae), Rheum spp. L. (Polygonaceae), Salvia lavandulaefolia Vahl. (Lamiaceae), Salvia miltiorrhizia Bung. (Lamiaceae), Salvia officinalis L. (Lamiaceae), Terminalia chebula L. (Combretaceae), Withania somnifera L. (Solonaceae), and so on.

Conclusion

Herbs may play a promising role in the early treatment of Alzheimer's and other conditions involving poor memory and dementia. One of the chief benefits is that they have a low toxicity compared to pharmaceutical agents. There is no reason why botanicals cannot be used adjunctively with drugs, or other complementary approaches such as SAMe, fish oil, and antioxidant vitamins. A review of the literature indicates that the sooner the treatment is started, the better will be the outcome. Therefore, if clients have family members with a history of Alzheimer's disease, or other states involving poor memory, they may start taking these remedies prior to the onset of symptoms, to delay or possibly prevent the advent of the symptoms. The acorus/ginkgo formula mentioned earlier (with salvia and gingko) and vinpurazine with naturally extracted huperzine A are two promising long-term therapies for people suffering from memory loss, dementia, and Alzheimer's disease.

The use of herbal medicines in the treatment of AD should be compared with the pharmacological treatment currently in use. Such studies should include identification of the active principle in order to improve the validation of the clinical trial. Further large-scale, multicenter studies are necessary to determine the effectiveness of these substances in the cognitive deterioration of AD. Until then, this review provides some evidence of the benefit of a wide rang of herbs (included in the Indian Medicine System, Chinese Medicine System, European Medicine System, etc.) in the treatment of AD.