Hypotensive ephedra

Chinese medical practitioners in the 15th century recommended ephedra as an antipyretic and antitussive agent. Modem physicians use intravenous ephedrine for the prophylaxis and treatment of hypotension caused by spinal anesthesia, particularly during cesarean section (see Chapter 29). 

A revised structure for the catecholamide spermidine siderophore obtained from Paracoccus denitrificans has been proposed the new structure contains a centrally located oxazole ring (6).3 The soft coral Sinularia brongersmai contains two spermidine derivatives, i.e. (7) and its 10,11-dehydro-derivative [(lOi )], both of which show cytotoxic activity.4 The hypotensive principle of the root bark of Lycium chinense has been isolated as an amorphous alkaloid called kukoamine A.5 Acid hydrolysis of the alkaloid produced only spermine and dihydrocaffeic acid, which, in association with its n.m.r. spectrum, indicated the structure (8). Another hypotensive principle, ephedradine B (9), has been obtained from Ephedra roots.6... 

Both ephedrine and pseudoephedrine remain worry-ingly popular (4) and are widely available without prescription. Based on increasing evidence of the risks of Ephedra self-medication, various national regulatory authorities are currently considering recalling Ephedra products from over-the-counter sales. Oral doses of ephedrine 25-30 mg are often prescribed, for example for orthostatic hypotension. Lower oral doses, present in some cold remedies in tablet form, are unlikely to be efficacious, although they are risky where the drug is... 

Ephedra has been closely linked to methamphetamine production. There are movements In many localities to outlaw the herb. There are many drug interactions with Ma huang. )9-BI(K kcrs may enhance the sympathetic effect and cause hypertentiion. MAOIs may interact with ephedra to cause hypertensive cri.si.s. Phcnothiaz.ines might block the or effects of ephedra, causing hypotension and tachycardia. Simultaneous use of theophylline may cau.se GI and CNS effects. In pregnancy, ephedra is absolutely contraindicated (uterine stimulation). Persons with heart disease, hypertension, and diabetes should not take ephedra. 

The medicinal use of Ephedra sinica in China dates from 2800bc. Ma Eluang (the stem and branch) was used primarily in the treatment of common cold, asthma, hay fever, bronchitis, edema, arthritis, fever, hypotension, and urticaria. Ephedra has been used to treat bronchoconstriction for centuries, because of its activity at /li-adrenergic receptors. It contains pseudoephedrine, ephedrine, and other similar alkaloids. These are sympathomimetics that either directly or indirectly stimulate a- and jS-adrenergic receptors. It has become less extensively used with the advent of more selective agonists. 

Herbal substitutes for dru [s of abuse A variety of herbal mixtures are offered for sale in magazines, on the internet and in so-called smart , eco or head shops. Many are marketed as herbal Ecstasy and the plants included in the formulations include Yohimbe bark, Kava-Kava (Piper methysticum),Y-3 e.emi, Hops, Jaborandi and Alisma. One product contains Kava-Kava, Guarana, Uva Ursi and Cascara bark. Many of the products sold as herbal Ecstasy contain either Ephedra sinica (Ma huang) or the Indian plant Sida cordifolia which both contain the alkaloid ephedrine (see R03c, Chapter VI). Other alkaloids may also occur, such as pseudoephedrine, norephedrine and norpseudoephedrine. The side-effects of ephedrine include tachycardia, anxiety, insomnia and arrythmias and a hypotensive crisis may develop if monamine oxidase inhibitors are also taken. Many adverse reactions and more than 20 deaths have been attributed to ephedrine and Ephedra consumption. Research conducted in the US shows that the daily intake of some Ephedra products would give ephedrine levels well above the recommended therapeutic doses. 

Various reports on the antihypertensive activity of lignans were published before 1997 [14], ( )-Pinoresinol diglucoside from Eucommia ulmoides (Eucommiaceae), pinoresinol monoglucoside from Forsythia spp., sesamin from sesame oil, neojusticin B from Justicia procumbens, ephedradine B (a hybrid neolignan-alkaloid) from Ephedra spp.(Ephedraceae), danshensuan B from Salvia miltiorrhiza (Labiatae) and magnolol from different sources were all reported to be hypotensives in different animal models. 

Ephedra alkaloids. Alkaloids from the shrubby joint fir [Ephedra, Ephedraceae) occurring in warm-temperate regions of the earth. The main alkaloid is ephedrine. Many of the constituents of Ephedra (Ma-Huang drug in Chinese traditional medicine) are hypotensive. 

Hikino H, Ogata M, Konno C (1983) Structure of feruloylhistamine, a hypotensive principle of Ephedra roots. Planta Med 48 108-110. doi 10.1055/s-2007-969900... 

Hikino H, Shimoyama N, Kasahara Y, Takahashi M, Konno C 1982 Structures of mahuannin A and B, hypotensive principles of Ephedra roots. Heterocycles 19 1381-1384... 

Indeed, PDC catalyzes mainly the reaction of pyruvate with benzaldehyde for the formation of (R)-PAC 27. This C—C bond formation, a two-carbon unit elongation, is coupled to the concomitant decarboxylation of pyruvate 26. This reaction is industrially developed for the synthesis of (—)-ephedrine by adding a second step, a reductive amination. Ephedrine (marketed by Merck especially) is a sympathomimetic amine commonly used as a stimulant, appetite suppressant, concentration aid, and decongestant, and it is used to treat hypotension associated with anesthesia. It is similar in structure to the (semisynthetic) derivatives amphetamine and meth-amphetamine. Chemically, it is an alkaloid derived from various plants in the genus Ephedra (family Ephedra-ceae). It works mainly by increasing the activity of noradrenaline on adrenergic receptors. ... 

Ephedrine, isolated from Ephedra sinica, is the major active constituent of this plant species. It is used in the treatment of asthma, nasal congestion, and as a prophylactic to avoid hypotension associated with spinal anesthesia for cesarean section [55]. Herbal products containing Ephedra are used as antiobesity agents and energy boosters despite reports on serious side-effects, such as hypertension, seizures, myocardial infarction [56]. The 15,2/ -(- -)-enantiomer of ephedrine is not present in the plant. 

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