zaterdag, oktober 15, 2022

Monografie van Meidoorn uit Pocket Guide to Herbal Medicine

Hawthorn (Crataegus laevigata (Poiret) D. C.)

➤ General comments: Many species of hawthorn are distributed throughout the moderate zones of the Northern Hemisphere. The use of its leaves and flowers as a remedy for heart disorders dates back to the nineteenth century.

➤ Pharmacology
– Herb: Hawthorn leaf and flower (Crataegi folium cum flore). The herb consists of the leaves and flowers of Crataegus laevigata DC. or, less frequently, of other hawthorn species.
– Important constituents: Flavonoids (1.8 %) such as hyperoside (0.28 %), rutin (0.17 %), and vitexin (0.2 %), and oligomeric procyanidins (2–3 %).
– Pharmacological properties: The procyanidins and flavonoids in hawthorn determine its therapeutic action. These substances effect an increase in coronary blood flow and dilate the blood vessels, thereby enhancing myocardial circulation and perfusion. The herb has positive inotropic, chronotropic and dromotropic effects, and improves the tolerance to hypoxia. The cardiotropic effects of Crataegus are attributed to an increase in the membrane permeability to calcium ions and an increase in the intracellular cyclic AMP concentration. Altogether, this makes the heart work more economically.

➤ Indications
– Supportive treatment for heart failure (NYHA class I–II)
– As a strengthening tonic for prevention of heart irregularities and conges-
tive heart failure

➤ Contraindications: None known.

➤ Dosage and duration of use
– Daily dose: 3.5–19.8 mg flavonoids, calculated as hyperoside (DAB 10), or 160–900 mg extract (4 : 1 to 7 : 1 with ethanol 45 % v/v or methanol 70 % v/v), corresponding to 30–168.7 mg oligomeric procyanidins, calculated as epicatechol. Hawthorn leaf/flower can be used for unlimited periods.

➤ Adverse effects: There are no known health hazards or side effects in conjunction with proper administration of the designated therapeutic doses of the herb.

➤ Herb–drug interactions: None known.

➤ Summary assessment: Clinical studies demonstrating the efficacy of hawthorn leaf/flower in NYHA class I–II heart failure are available.

✿ Literature
– Monographs: DAB 1998; ESCOP; Commission E
– Scientific publications; Bahorun T, Gressier B, Trotin F et al: Oxygen species scavenging activity of phenolic activities, fresh plant organs and pharmaceutical preparations. Arzneim Forsch 46 (1996), 1086–1089;
Kaul R: Pflanzliche Procyanidine. Vorkommen, Klassifikation und pharmakologische Wirkungen. PUZ 25 (1996), 175–185; Tauchert M, Loew D:
Crataegi folium cum flore bei Herzinsuffizienz. In: Loew, D., Rietbrock, N. (Ed): Phytopharmaka in Forschung und klinischer Anwendung. Steinkopf Verlag, Darmstadt (1995), 137–144.

Pocket Guide to Herbal Medicine
Karin Kraft, M.D. Professor Outpatient Clinic University of Rostock Germany
Christopher Hobbs, L.Ac., A.H.G. Clinical Herbalist and Acupuncturist in Private Practice. Davis, California USA

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