Horseradish

Summary and Pharmaceutical Comment

The chemistry of horseradish is well established and it is recognised as one of the richest plant sources of peroxidase enzymes.(G48) Little pharmacological information was located, although the isothiocyanates and peroxidases probably account for the reputed circulatory stimulant and wound-healing actions, respectively. The oil is one of the most hazardous of all essential oils and it is not recommended for either external or internal use.(G58) Horseradish should not be ingested in amounts exceeding those used in foods.

Species (Family)

Armoracia rusticana P. Gaertin., B. Mey. & Scherb.

Synonym(s)

Armoracia lapathifolia, Cochlearia armoracia L., Nasturtium armoracia (L.) Fr.

Part(s) Used

Root

Pharmacopoeial and Other Monographs

Complete German Commission E(G3)

Martindale 35th edition(G85)

Legal Category (Licensed Products)

GSL(G37)

Constituents

The following is compiled from several sources, including General References G40, G58 and G62.

Coumarins Aesculetin, scopoletin.(1)

Phenols Caffeic acid derivatives and lesser amounts of hydroxycinnamic acid derivatives. Concentrations of acids are reported to be much lower in the root than in the leaf.(1)

Volatile oils Glucosinolates (mustard oil glycosides) gluconasturtiin and sinigrin (S-glucosides), yielding phenylethylisothiocyanate and allylisothiocyanate after hydrolysis. Isothiocyanate content estimated as 12.2–20.4 mg/g freeze dried root.(2, 3) Other isothiocyanate types include isopropyl, 3-butenyl, 4-pentenyl, phenyl, 3-methylthiopropyl and benzyl derivatives.(4)

Other constituents Ascorbic acid, asparagin, peroxidase enzymes, resin, starch and sugar.

Other plant parts Kaempferol and quercetin have been documented for the leaf.

Food Use

Horseradish is listed by the Council of Europe as a natural source of food flavouring (category N2). This category indicates that

horseradish can be added to foodstuffs in small quantities, with a possible limitation of an active principle (as yet unspecified) in the final product.(G16) Previously horseradish has been listed as GRAS (Generally Recognised As Safe).(G57) Horseradish is commonly used as a food flavouring.

Herbal Use

Horseradish is stated to possess antiseptic, circulatory and digestive stimulant, diuretic and vulnerary properties.(G42, G49, G64) Traditionally, it has been used for pulmonary and urinary

Figure 1 Selected constituents of horseradish.

H

Figure 2 Horseradish (Armoracia rusticana).

Clinical studies

There is a lack of clinical research assessing the effects of horseradish.

Side-effects, Toxicity

There is a lack of clinical safety and toxicity data for horseradish and further investigation of these aspects is required.

Isothiocyanates are reported to have irritant effects on the skin and also to be allergenic.(G51, G58) Animal poisoning has been

documented for horseradish. Symptoms described include inflam-

mation of the stomach or rumen, and excitement followed by collapse.(G33)

Contra-indications, Warnings

It is stated that horseradish may depress thyroid function, and

should be avoided by individuals with hypothyroidism or by those receiving thyroxine.(G42, G49) No rationale for this statement is

included, except that this action is common to all members of the cabbage and mustard family.

Drug interactions None documented. However, the potential for preparations of horseradish to interact with other medicines

Figure 3 Horseradish – dried drug substance (root).

administered concurrently, particularly those with similar or opposing effects, should be considered.

Pregnancy and lactation Allylisothiocyanate is extremely toxic and a violent irritant to mucous membranes.(G58) In view of this,

use of horseradish should be avoided during pregnancy and lactation.

Preparations

Proprietary multi-ingredient preparations

Australia: Garlic and Horseradish þ C Complex; Garlic, Horseradish, A & C Capsules; Procold. Germany: Angocin Anti-Infekt N. Malaysia: Horseradish Plus. Switzerland: Kernosan Elixir; Sanogencive. UK: Mixed Vegetable Tablets.

References

1Stoehr H, Herrman K. Phenolic acids of vegetables. III. Hydroxycinnamic acids and hydroxybenzoic acids of root vegetables.

Z Lebensm-Unters Forsch 1975: 159: 219–224.

2 Hansen H. Content of glucosinolates in horseradish (Armoracia rusticana). Tidsskr Planteavl 1974; 73: 408–410.

3 Kojima M. Volatile components of Wasabia japonica. II. Volatile components other than isothiocyanates. Hakko Kogaku Zasshi 1971; 49: 650–653.

4Kojima M et al. Studies on the volatile components of Wasabia japonica, Brassica juncea, and Cocholearia armoracia by gas chromatography-mass spectrometry. Yakugaku Zasshi 1973; 93: 453– 459.

5Sjaastad OV et al. Hypotensive effects in cats caused by horseradish peroxidase mediated by metabolites of arachidonic acid. J Histochem Cytochem 1984; 32: 1328–1330.

Summary and Pharmaceutical Comment

Limited information is available on the chemistry of hydrangea, although related species have been investigated more thoroughly.(G41) No scientific evidence was located to justify the herbal uses. In view of the lack of toxicity data, excessive use of hydrangea and use during pregnancy and lactation should be avoided.

Species (Family)

Hydrangea arborescens L. (Saxifragaceae)

Synonym(s)

Mountain Hydrangea, Seven Barks, Smooth Hydrangea, Wild

Hydrangea

Part(s) Used

Rhizome, Root

Pharmacopoeial and Other Monographs

BHP 1996(G9)

Martindale 35th edition(G85)

Legal Category (Licensed Products)

GSL(G37)

Constituents

The following is compiled from several sources, including General Reference G40.

Limited information is available on the chemistry of hydrangea. It is stated to contain carbohydrates (e.g. gum, starch, sugars), flavonoids (e.g. kaempferol, quercetin, rutin), resin, saponins, hydrangin and hydrangenol, a stilbenoid,(1) and to be free from tannins.

Food Use

Hydrangea is not used in foods. Previously in the USA, hydrangea has been listed as a 'Herb of Undefined Safety'.(G22)

Herbal Use

Hydrangea is stated to possess diuretic and antilithic properties. Traditionally, it has been used for cystitis, urethritis, urinary

Figure 1 Selected constituents of hydrangea.

H

Figure 2 Hydrangea (Hydrangea arborescens).

calculi, prostatitis, enlarged prostate gland, and specifically for urinary calculi with gravel and cystitis.(G7, G64)

Dosage

Dosages for oral administration (adults) for traditional uses recommended in standard herbal reference texts are given below.

Dried rhizome/root 2–4 g as a decoction three times daily.(G7)

Liquid extract 2–4 mL (1 : 1 in 25% alcohol) three times daily.(G7)

Tincture 2–10 mL (1 : 5 in 45% alcohol) three times daily.(G7)

Pharmacological Actions

In vitro and animal studies

None documented for hydrangea. Synthesised hydrangenol derivatives have been reported to possess anti-allergic properties,

Figure 3 Hydrangea – dried drug substance (rhizome).

370 Hydrangea

exhibiting a strong inhibitory action towards hyaluronidase activity and histamine release.(2)

Clinical studies

There is a lack of clinical research assessing the effects of hydrangea and rigorous randomised controlled clinical trials are required.

Side-effects, Toxicity

There is a lack of clinical safety and toxicity data for hydrangea and further investigation of these aspects is required.

Hydrangea has been reported to cause contact dermatitis, (G51) and it is stated that hydrangin may cause gastroenteritis.(G22) Symptoms of overdose are described as vertigo and a feeling of tightness in the chest.(G22)

HContra-indications, Warnings

None documented.

Drug interactions None documented. However, the potential for preparations of hydrangea to interact with other medicines administered concurrently should be considered.

Pregnancy and lactation The safety of hydrangea has not been established. In view of the lack of phytochemical, pharmacological and toxicity data, the use of hydrangea during pregnancy and lactation should be avoided.

Preparations

Proprietary multi-ingredient preparations

UK: Antiglan; Backache.

References

1 Harborne JB, Baxter H. Phytochemical Dictionary. London: Taylor and Francis, 1993.

2Kakegawa H et al. Inhibitory effects of hydrangeol derivatives on the activation of hyaluronidase and their anti-allergic activities. Planta Med 1988; 54: 385–389.