Brassica alba/nigra Common name: Black mustard, mustard
Parts used: Seed
Constituents: Fixed oil (30%) , Sinapine , Sinapic acid, Fixed oil, Protein, Mucilage.
Medicinal actions: Rubefacient, counter-irritant, stimulant, diuretic, emetic
Medicinal use: Mustard seed powder has been used historically as a topical application to create a counter-irritant effect. This well known spice has its main use in medicine as a stimulating external application. The rubefacient action causes a mild irritation to the skin, stimulating circulation to that area and relieving muscular and skeletal pain. An infusion or poultice of mustard with aid in cases of bronchitis when applied over the chest.
Pharmacy: Plaster: Mix 100g freshly ground mustard seeds with warm water to form a thick paste. This is spread on a piece of cloth to the size of the body area that is to be covered. To stop the paste sticking to the skin, lay a dampened gauze on the skin. Apply the cloth and remove after 1 minute. The skin may be reddened by this treatment which can be eased by applying olive oil afterwards. It should never be left on any longer than 15-30 minutes. At the first sensation of burning felt by the patient, the plaster should be removed. The local counter-irritant effect may persist for 24-48 hours.
Toxicity: Mustard seed applications if left on too long or over sensitive skin will cause vesication that can cause skin ulceration, necrosis and permanent scaring. Mustard seed applications are contraindicated when there is severe circulatory damage and with varicose veins. Mustard seed is not to be used internally in amounts greater than those for culinary purposes.