Shepherd’s Purse

Summary and Pharmaceutical Comment

The chemistry of shepherd’s purse is well documented. Several actions affecting the circulatory system have been observed in animal studies, although these actions do not relate to the traditional herbal uses. There is a lack of robust clinical research assessing the efficacy and safety of shepherd’s purse. Limited toxicity data are available. In view of this together with the demonstrated pharmacological activity of the herb, excessive use of shepherd’s purse and use during pregnancy and lactation should be avoided.

Species (Family)

Capsella bursa-pastoris (L.) Medik (Brassicaceae/Cruciferae)

Synonym(s)

Capsella

Part(s) Used

Herb

Pharmacopoeial and Other Monographs

BHP 1996(G9)

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 G2 and G7.

Amines Acetylcholine, choline, amino acids 2.33% (major component proline), histamine, tyramine and unidentified crystalline alkaloids.(1)

Flavonoids Quercetin, diosmetin, luteolin, hesperetin and their glycosides (e.g. rutin, diosmin, hesperidin).(2)

Volatile oils 0.02%. Camphor (major); at least 74 components identified.(3, 4)

Other constituents Carotenoids, fumaric acid, sinigrin (mustard oil glucoside), ascorbic acid (vitamin C) and vitamin K.(4, 5, G2)

Food Use

Shepherd's purse is not used in foods.

Herbal Use

Shepherd's purse is stated to possess antihaemorrhagic and urinary antiseptic properties. Traditionally, it has been used for

menorrhagia, haematemesis, haematuria, diarrhoea and acute catarrhal cystitis.(G2, G7, G64)

Dosage

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

Dried herb 1–4 g as an infusion three times daily(G7)

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

Figure 1 Selected constituents of shepherd’s purse.

Figure 3 Shepherd’s purse – dried drug substance (herb).

542 Shepherd’s Purse

Pharmacological Actions

In vitro and animal studies

A variety of actions has been documented for an ethanolic extract of shepherd's purse in various animal models.(6–9) Anti-inflam- matory activity has been exhibited versus carrageenan-induced and dextran-induced rat paw oedema.(7) A reduction in capillary permeability in the guinea-pig, induced by histamine and serotonin, has also been observed,(7) and flavonoid components isolated from shepherd's purse have been reported to reduce blood vessel permeability in mice.(2) Anti-ulcer activity has been documented in rats following intraperitoneal injection. The extract did not affect gastric secretion, but accelerated recovery from stress-induced ulcers.(7) A hypotensive effect observed in cats, dogs, rabbits and rats, following intravenous injection, was inhibited by a b-adrenoceptor blocker but not by atropine, thus dismissing earlier reports that this action was attributable to cholinergic compounds present in shepherd's purse.(8, 9)

Diuresis has been reported in mice, following oral or intraperitoneal administration of shepherd's purse. The mode of action was stated to involve an increase in the glomerular filtration rate.(7)

Documented cardiac actions include increased coronary blood flow in dogs following intra-arterial administration, and a slight inhibitory effect on ouabain-induced ventricular fibrillation in the rat following intraperitoneal injection, together with a negative chronotropic effect.(9) Studies on the isolated heart have reported negative chronotropic and inotropic actions in the guinea-pig and rabbit and coronary vasodilatation.(9)

A CNS-depressant action in mice has been demonstrated (potentiation of barbiturate-induced sleeping time).(9)

Weak antibacterial activity, mainly towards Gram-positive organisms, has been reported.(10)

Antineoplastic activity in rats has been documented for fumaric acid, which prevented the development of hepatic neoplasms when co-administered with the carcinogen 3-MeDAB.(11)

Shepherd's purse seeds are stated to possess rubefacient and vesicant properties because of their isothiocyanate-yielding components.(G51)

In vitro studies have documented stimulatory action in various smooth muscle tissues. Induced contractions of the small intestine in the guinea-pig were reported to be unaffected by atropine and diphenhydramine, but were inhibited by papaverine.(8, 9) Induced utero-activity in the rat, equivalent to the effect of oxytocin 0.1 i.u., was unaffected by atropine, but inhibited by competitive inhibitors

Sof oxytocin.(8) Two unidentified alkaloid components of shepherd's purse have also been stated to elicit a physiological activity on the uterus.(1) Induced tracheal contractions in the guinea-pig were

unaffected by adrenaline, which did inhibit acetylcholine-induced contractions.(9) These studies concluded that the active substance

(s)in shepherd's purse responsible for the observed actions on smooth muscle were neither acetylcholine nor histamine.(8, 9)

Clinical studies

There is a lack of clinical research assessing the effects of shepherd's purse and rigorous randomised clinical trials are required.

Side-effects, Toxicity

Clinical data

There is a lack of clinical safety and toxicity data for shepherd's purse and further investigation of these aspects is required.

Preclinical data

Shepherd's purse extracts have been reported to exhibit low toxicity in mice. LD50 values reported are 1.5 g/kg body weight (mice, intraperitoneal injection) and 31.5 g/kg (mice, subcutaneous injection).(9) Signs of toxicity were described as sedation, enlargement of pupils, paralysis of hind limbs, difficulty in respiration, and death by respiratory paralysis.(9) Following hydrolysis, the constituent sinigrin yields allyl isothiocyanate which is an extremely powerful irritant and produces blisters on the skin.(G41) Isothiocyanates have been implicated in endemic goitre (hypothyroidism with thyroid enlargement) and have been reported to produce goitre in experimental animals.(G41)

Contra-indications, Warnings

Drug interactions None documented. However, the potential for preparations of shepherd's purse to interact with other medicines administered concurrently, particularly those with similar or opposing effects, should be considered. There is limited evidence from preclinical studies that shepherd's purse and/or certain isolated constituents have hypotensive, diuretic and cardiac activities and effects on thyroid fuction.

Pregnancy and lactation Shepherd's purse is reputed to act as

an abortifacient and to affect the menstrual cycle, and tyramine is documented as a utero-active constituent.(G30) In view of this, the

reported oxytocin-like activity and the general lack of safety data, the use of shepherd's purse during pregnancy and lactation should be avoided.

Preparations

Proprietary multi-ingredient preparations

UK: Fenneherb Cystaid.

References

1Kuroda K, Kaku T. Pharmacological and chemical studies on the alcohol extract of Capsella bursa-pastoris. Life Sci 1969; 8: 151–155.

2 Jurisson S. Flavonoid substances of Capsella bursa pastoris.

Farmatsiya (Moscow) 1973; 22: 34–35.

3Miyazawa M et al. The constituents of the essential oils from Capsella bursa-pastoris Medik. Yakugaku Zasshi 1979; 99: 1041–1043.

4 Park RJ. The occurrence of mustard oil glucosides in Lepidium hyssopifolium, L. bonariense, and Capsella bursa pastoris. Aust J Chem 1967; 20: 2799–2801.

5Jurisson S. Vitamin content of shepherd's purse. Farmatsiya (Moscow) 1976; 25: 66–67.

6Kuroda K, Takagi K. Studies on Capsella bursa pastoris. I. General pharmacology of ethanol extract of the herb. Arch Int Pharmacodyn Ther 1969; 178: 382–391.

7Kuroda K, Takagi K. Studies on capsella bursa pastoris. II. Diuretic, anti-inflammatory and anti-ulcer action of ethanol extracts of the

herb. Arch Int Pharmacodyn Ther 1969; 178: 392–399.

8 Kuroda K, Takagi K. Physiologically active substance in Capsella bursa-pastoris. Nature 1968; 220: 707–708.

9Jurisson S. Determination of active substances of Capsella bursa pastoris. Tartu Riiliku Ulikooli Toim 1971; 270: 71–79.

10Moskalenko SA. Preliminary screening of far-eastern ethnomedicinal plants for antibacterial activity. J Ethnopharmacol 1986; 15: 231–259.

11Kuroda K. Neoplasm inhibitor from Capsella bursa pastoris. Japan Kokai 1977; 41: 207.

Skunk Cabbage

Summary and Pharmaceutical Comment

There is only limited information available on the constituents, pharmacological activities and safety of skunk cabbage (even though citings as early as 1817 reported its irritant properties). No documented evidence was found to justify the herbal uses. In view of the lack of data, the appropriateness of medicinal use of skunk cabbage should be considered. In view of the documented irritant properties, excessive use, at least, should be avoided. Skunk cabbage should not be used during pregnancy and breastfeeding. The potential for skunk cabbage preparations to interact with other medicines should be considered.

Species (Family)

Symplocarpus foetidus (L.) Salisb. ex W. Barton (Araceae)

Synonym(s)

Dracontium foetidum L., Skunkweed

Part(s) Used

Rhizome, root

Pharmacopoeial and Other Monographs

BHP 1983(G7)

Martindale 35th edition(G85)

Legal Category (Licensed Products)

GSL(G37)

Constituents

Reported constituents include starch, gum-sugar, fixed and volatile oils, resin, tannin, an acrid principle and iron.(G22, G64)

Other plant parts Large amounts of alkaloids (unspecified), phenolic compounds and glycosides have been isolated from all plant parts of skunk cabbage.(1) The leaves are reported to contain hydroxytryptamine.(G22) The flower contains the anthocyanins cyanidin-3-monoglucoside, cyanidin-3-rutinoside and peonidin-3- rutinoside.(2)

Food Use

Skunk cabbage is not used in foods.

Herbal Use

Skunk cabbage is stated to possess expectorant, antispasmodic and mild sedative properties. Traditionally, it has been used for

bronchitis, whooping cough, asthma and specifically for bronchitic asthma.(G7, G64)

Figure 1 Skunk cabbage (Symplocarpus foetidus).

Dosage

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

Powdered rhizome/root 0.5–1.0 g in honey or as an infusion or decoction three times daily.(G7)

Liquid extract 0.5–1.0 mL (1 : 1 in 25% alcohol) three times daily.(G7)

Figure 2 Skunk cabbage – dried drug substance (rhizome).

544 Skunk Cabbage

Pharmacological Actions

In vitro and animal studies

None documented for the rhizome/root. There is a preliminary report of bacteriostatic activity for ethanol extracts of skunk cabbage (plant parts not specified), although data on minimum inhibitory concentrations were not provided. The leaf extract has haemolytic properties,(G23) although the scientific basis for this statement is not clear.

Clinical studies

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

Side-effects, Toxicity

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

The root is reported to be bitter and acrid, with a disagreeable odour. Severe itching and inflammation of the skin has been documented.(G51) No published toxicity studies were located.

Contra-indications, Warnings

It has been stated that the fresh plant can cause blistering.(G42) In

view of the acrid principle thought to be present in both the dried and fresh root,(G51) skunk cabbage should be used with caution.

Drug interactions None documented. In view of the lack of information on the constituents of skunk cabbage and their pharmacological activities, the potential for skunk cabbage preparations to interact with other medicines used concurrently should be considered.

Pregnancy and lactation Skunk cabbage is reputed to affect the menstrual cycle(G22) although the scientific basis for this statement

is not clear. In view of the lack of phytochemical, pharmacological, and toxicological information, and the irritant properties, the use of skunk cabbage during pregnancy and lactation should be avoided.

Preparations

Proprietary multi-ingredient preparations

UK: Horehound and Aniseed Cough Mixture; Vegetable

Cough Remover.

References

1Konyukhov VP et al. Dynamics of the accumulation of biologically active agents in Lysichitum camtsochatcense and Symplocarpus

foetidus. Uch Zap Khabarovsk Gos Pedagog Inst 1970; 26: 59–62.

2Chang N et al. Anthocyanins in Symplocarpus foetidus (L.) Nutt. (Araceae). Bot J Linn Soc 1970; 63: 95–96.