Traditional Medicine for Memory Enhancement

Keywords • Acetylcholinesterase inhibitors • Alzheimer’s disease • Anti-inflammatory • Antioxidant • Estrogenic • Memory • Traditional medicine In traditional practices of medicine, numerous plants have been used to alleviate memory impairment both in healthy individuals and those with disease states which are now recognised as specific cognitive disorders such as Alzheimer’s disease. An ethnopharmacological approach has provided leads to identify plants and their compounds that may have potential to modulate cognitive abilities by different modes of action. A variety of therapeutic targets have been identified as relevant in the treatment of cognitive disorders, including modulation of the cholinergic system, which may be achieved by the inhibition of acetyl-cholinesterase, and neuroprotection against glutamate-induced overstimulation of N-methyl-D-aspartate (NMDA) receptors, by the use of NMDA receptor modulators. Other activities considered to be relevant in the alleviation of cognitive impairment include anti-inflammatory, antioxidant and estrogenic activities. Two of the currently licensed drugs used to treat cognitive symptoms in Alzheimer’s disease, galantamine and rivastigmine, Read more […]

Activities Relevant to the Treatment of Cognitive Disorders

Precursors of Acetylcholine Adequate availability of choline has been proposed to enable sufficient acetylcholine synthesis for neurotransmission. Precursors of acetylcholine (e.g. choline and lecithin) have been investigated for their effects on synthesis and release of acetylcholine, with a view to increasing acetylcholine release and cholinergic activity. Few clinical or animal studies have reported any significant beneficial effects on cognitive function with these compounds. Therapy failure may be due to impaired uptake mechanisms of choline causing the reduction in acetylcholine synthesis, and not due to insufficient choline supply. This is apparent as it has been reported that more choline occurs in the cerebrospinal fluid of Alzheimer’s disease patients than in patients without Alzheimer’s disease, and that choline levels increase with disease progression. Therapy with acetylcholine precursors may be limited by side-effects, including gastrointestinal disturbances such as nausea, vomiting and diarrhoea. Muscarinic Receptor Stimulation Direct cholinergic receptor stimulation has been explored as one therapeutic target to enhance cognitive function. Cholinergic agonists are reported to facilitate learning Read more […]

Physostigma venenosum

The calabar bean, the seeds of Physostigma venenosum Balf. (Leguminosae), was used traditionally in Africa, particularly south-eastern Nigeria, for ritual deaths associated with the funeral of a chief and as an ordeal poison, claimed to determine the guilt or innocence of persons accused of a crime. Rapid death was an indication that the suspect was guilty and innocence was shown by survival. This logic does appear to have some scientific basis, as differences in absorption might arise due to psychosomatic influences, with nervous sipping by guilty suspects enabling greater absorption. The toxic effects of the calabar bean extract were found to be due to excessive cholinergic stimulation resulting in increased salivation, nausea, bradycardia, muscle cramps and respiratory failure, as well as CNS effects. This effect was attributed to the presence of an alkaloid with an unusual pyrroloindole skeleton, physostigmine, also known as eserine, which potently inhibits acetylcholinesterase. Physostigmine has been shown to inhibit both G1 and G4 acetylcholinesterase forms, the major acetylcholinesterase isoenzymes present in mammalian CNS. Physostigmine also inhibits with similar potency butyrylcholinesterase, an enzyme that Read more […]

Ginkgo biloba: Clinical Use

Ginkgo biloba is a complex herb that contains many different active constituents and works by means of multiple mechanisms. In practice, its therapeutic effect is a result of interactions between constituents and mechanisms, giving it applications in many varied conditions. To date, most of the research conducted in Europe has used a standardised preparation known as EGb 761, available commercially as Rokan, Tanakan or Tebonin. DEMENTIA, MEMORY IMPAIRMENT Ginkgo biloba has been used and studied as a cognitive activator in a variety of populations, such as cognitively intact people, those with cerebral insufficiency, age-related memory impairment, Alzheimer’s dementia or multi-infarct dementia. A 2002 Cochrane review of the scientific literature concluded that Ginkgo biloba produces benefits superior to placebo within 12 weeks’ treatment in people with acquired cognitive impairment, including dementia, of any degree of severity. Cognition, activities of daily living and measures of mood and emotional function show significant benefit for ginkgo compared with placebo. Some clinical studies have also found that EGb 761 improves the capacity of geriatric patients to cope with the stressful demands of daily life. Clinical Read more […]