Sweet clover
Botanical name
Yellow sweet clover, yellow melilot, ribbed melilot or common melilot - Melilotus officinalis (L.) Lam
Family
Legume/Pea family (Fabaceae)
Information about the plant
The clover is widely spread across Europe and Asia, along paths and around fields. The genus name Melilotus comes from the Greek ‘meli’ (= honey) and ‘lotos’ (= clover in the broad sense). In fact, the numerous fragrant, bright yellow flowers make an excellent pasture for honey bees. The epithet officinalis suggests that it is an old medicinal plant, because the "officina" is the sales room of a pharmacy and ‘officinalis’ means: used in the pharmacies. Its preferred sites are namely the rocky road and field margins, and the threefold symmetry of the leaves is very characteristic. Clover will grow to almost 1m high. On the long stems are the threefold obovate leaves, irregular slightly toothed leaflets. The little yellow butterfly flowers are in 30 to 70 one-sided bunches. When the fruit ripens, the light-brown rounded husks form. The flowering period is May to September.
Medicinally used parts of plants (herbal drug)
The dried herb collected during the flowering period is used. An enzymatic process during drying creates the volatile coumarin that gives the drug its characteristic scent. The drug comes from farms in Eastern European countries.
Constituents of the herbal drug
Sweet clover contains coumarin, melilotoside, flavonoids and saponins.
Quality of the drug
The quality of the sweet clover herb (herba meliloti) is specified in the European Pharmacopoeia (Ph. Eur.).
Medical applications
Recognised medical use
Internally for complaints of chronic venous insufficiency such as pain and heaviness in the legs, night cramps, itchiness and swelling (Commission E, ESCOP). Furthermore to support the treatment of thrombophlebitis, post-thrombotic syndrome, haemorrhoids and lymphatic congestion and externally for bruises, sprains and superficial bruises (Commission E). The HMPC has classified Sweet clover as a traditional herbal medicinal product (see "traditional use").
Traditional use
Sweet clover was categorised by the HMPC as a traditional herbal medicine (§ 39a AMG). Based on many years of experience, Sweet clover is used internally and externally for the relief of symptoms that arise in connection with mild venous disorders, such as heaviness in the legs. Externally also for the treatment of bruises, sprains and insect bites. Traditionally used to improve the condition of tired legs (traditional use acc. to § 109a).
Herbal drug preparations in finished dosage forms
- cut drug to prepare tea
- fluid extract in liquids
- dried extract in tablets and capsules
- mother tincture in drops and other liquids
Dosage
Prepared drugs: see package insert;
Tea infusion: It is not recommended to drink sweet clover tea due to the fluctuating coumarin content in the drug (see side effects).
Notes
Sweet clover should not be taken with anticoagulant (blood thinning) agents. Patients with liver disease in their medical history should not take Sweet clover. The ingestion of sweet clover herb during pregnancy and breast-feeding is not recommended, because there are as yet no findings on its safety, likewise there are no findings for its use in children and adolescents under 18 years old.
Side effects
Occasional stomach upset and allergic symptoms. Coumarin has been shown in various animal species as being hepatotoxic. The presumption of mutagenic, genotoxic and carcinogenic effect has not been confirmed. As a precaution, the daily intake of 5mg of coumarin should not be exceed.
Interactions
Interactions with anticoagulant (blood thinning) agents have been reported.
References
Herbal drug monographs
Further literature
Wichtl: Teedrogen und Phytopharmaka, pg. 430
Schilcher: Leitfaden Phytotherapie, pg. 249
Van Wyk: Handbuch der Arzneipflanzen, pg. 203
Kommentar zum Europäischen Arzneibuch (Sweet clover, no. 2120)