CHINESE HERB Treatment ALZHEIMERS #7

OTHER CHOLINESTERASE INHIBITORS FROM CHINESE HERBS

Lycorus radiata (shisuan) 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. Lycorine produces a marked sedative action in mice and rats, and it prolongs sleep time in animals treated with pentobarbital. Lycorine could also potentiate the analgesic effects of morphine and corydalis.

Macleaya cordata (boluohui) in the Papaveraceae family, 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) contains berberine alkaloids, mainly berberine, but also coptisine, worenine, palmatine, and columbamine. Berberine is a cholinesterase inhibitor. When given to mice at 0.250 mg/kg, berberine enhances establishment of positive conditional reflex, but high dosages (10 to 20 times higher) inhibit it. 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.

Berberis species (sankezhen) are another source of berberine and also provide berbamine, palmatine, isotetrandrine, and jatrorrhizine. Palmatine was shown to have strong anticholinesterase activity. Isotetrandrine (also found in Stephania species), antagonizes ileal contraction induced by histamine or acetylcholine. Jatrorrhizine reduces spontaneous activity of mice and prolongs the animals sleep elicited by pentobarbital; it also induces sleep in mice given subthreshold doses of pentobarbital.

Securinega suffruticosa (yiyiqiu) 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 (longkui), contains solanine, salasodine, and related alkaloids. Salasodine reduces sensitivity of animals to pain. 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.

SOURCES

Except for the general information about the nature of Alzheimer's disease and its treatment with Western medicine, which is available from many sources, the information for this article was derived from three sources:
Chang HM and But PPH, Pharmacology and Applications of Chinese Materia Medica, (2 vols.) 1987 World Scientific, Singapore (USA office: Teaneck NJ).
But PPH, et al., (eds.), Abstracts of Chinese Medicine, 1986-1995, Chinese University of Hong Kong, Shatin, N.T., Hong Kong. This is a quarterly journal.
Fu KZ and Fruehauf H, Senile Dementia and Alzheimer's Disease, 1995 Institute for Traditional Medicine, Portland, OR. This is a collection of unedited papers produced for ITM from a review of Chinese language literature.
July 1996

http://www.itmonline.org/arts/alzheimers.htm