Wild cabbage-Brassica oleracea-Poisonous plants-Glucosinolates, S-methyl-L-cysteine sulfoxide

Wild cabbage

General poisoning notes:

Brassica oleracea includes common cultivated crops such as kale, broccoli, Brussels sprouts, and cabbage. All these vegetables are capable of forming toxic quantities of SMCO, a chemical that can cause hemolytic anemia in livestock. These plants also contain glucosinolates, which can cause goiter. In general, these widely used vegetables are safe for human consumption. Cases of livestock poisoning occur when they are used almost exclusively as fodder for animals (Kingsbury 1964, Smith 1980, Cheeke and Schull 1985, Benevenga et al. 1989). Glucosinolates contained in kale, cabbage, and broccoli (Brassica oleracea) can cause goiter in humans. These plants cause goiter in less than 5% of cases in humans. The chemicals cause a reduction in performance of young livestock, especially swine and poultry (Fenwick et al. 1989). It is important to note that the frequency of toxicity has dropped dramatically since a few decades ago. Researchers have changed the quantity of toxic compounds in the entire Brassica spp., creating new cultivars with lower quantities of these chemicals. The threat of poisoning from some of the plants has diminished or virtually disappeared in some cultivars. For example, the Canadian development of rapeseed into the so-called "double-zero" cultivars (low in glucosinolates and in erucic acid) has allowed rapeseed meal to be used for livestock at much higher levels without reducing performance (Cheeke and Schull 1985).

Description:

Herbs biennial or perennial, rarely annual, (0.3-)0.6-1.5(-3) m tall, glabrous, glaucous. Stems erect or decumbent, branched at or above middle, sometimes fleshy at base. Basal and lowermost cauline leaves long petiolate, sometimes strongly overlapping and forming a head; petiole to 30 cm; leaf blade ovate, oblong, or lanceolate in outline, to 40 × 15 cm, margin entire, repand, or dentate, sometimes pinnatifid or pinnatisect and with a large terminal lobe and smaller, 1-13, oblong or ovate lateral lobes on each side of midvein. Upper cauline leaves sessile or subsessile in some cultivated forms, oblanceolate, ovate, or oblong, to 10 × 4 cm, base amplexicaul, auriculate, or rarely cuneate, margin entire, repand, or rarely dentate. Racemes sometimes fleshy and condensed into a head. Fruiting pedicels usually straight, ascending or divaricate, (0.8-)1.4-2.5(-4) cm. Sepals oblong, 0.8-1.5 cm × 1.5-2.7 mm, erect. Petals creamy yellow or rarely white, (1.5-)1.8-2.5(-3) × (0.6-)0.8-1.2 cm, ovate or elliptic, apex rounded; claw 0.7-1.5 cm. Filaments 0.8-1.2 cm; anthers oblong, 2.5-4 mm. Fruit linear, (2.5-)4-8(-10) cm × (2.5-)3-4(-5) mm, terete, sessile or on a gynophore to 3 mm, divaricate or ascending; valvular segment (2-)3-7.5(-9) cm, 10-20-seeded per locule, valves with a prominent midvein; terminal segment conical, (3-)4-10 mm, seedless or 1(or 2)-seeded; style obsolete. Seeds dark brown or blackish, globose, 1.5-2.5 mm in diam., minutely reticulate. Fl. Mar-Jun, fr. Apr-Jul. 2n = 18*.

Nomenclature:

Scientific Name: Brassica oleracea L.

Vernacular name(s): wild cabbage

Scientific family name: Cruciferae

Vernacular family name: mustard

Distribution:

Throughout China [native to W Europe; cultivated worldwide]. Canada: Newfoundland, Prince Edward Island, Ontario, Quebec.

Notes on Poisonous plant parts:

SMCO is most abundant in young leaves and growing points. Brussels sprouts can have high amounts of the chemical, as can the flowering parts of the plants. The most drastic hemolytic anemia occurs when these plants form exclusive fodder for livestock (Smith 1980).

Toxic parts:

All parts, leaves, flowers.

Notes on Toxic plant chemicals:

Glucosinolates are chemicals that can inhibit the function of the thyroid gland. Various components of the chemicals can be detrimental to both humans and livestock. Goitrin inhibits thyroid function. Thiocynates and isothiocyanates inhibit iodine uptake by the thyroid gland. Nitriles can be formed from glucosinolates and these chemicals are toxic, affecting the liver and kidneys (Cheeke and Schull 1985). SMCO (S-methyl-L-cysteine sulfoxide) is an alpha-amino acid that causes hemolytic anemia in livestock. This chemical is restricted to various members of the family Cruciferae in the genera Brassica and Raphanus as well as the family Liliaceae in the genus Allium (onions). Additional notes on this chemical can be found under members of these genera. The concentration of SMCO in kale plants may double as the plants mature. The quantity of SMCO is increased with the addition of nitrogen to high-sulfate soils. SMCO can be greatly reduced in low-sulfate soils. The variation of SMCO varies greatly amongst different varieties of plants in the genus Brassica, suggesting that concentrations of SMCO may be heritable (Benevenga et al. 1989).

Toxic plant chemicals:

Glucosinolates, S-methyl-L-cysteine sulfoxide (SMCO)

Chemical diagram(s) are courtesy of Ruth McDiarmid, Biochemistry Technician, Kamloops Range Station, Agriculture and Agri-Food Canada, Kamploops, British Columbia, Canada.

Animals/Human Poisoning:

Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.

Cattle

General symptoms of poisoning:

Heinz bodies, hemoglobinuria, weight gain, reduced.

Goats

General symptoms of poisoning:

Heinz bodies, hemoglobinuria.

Humans

General symptoms of poisoning:

Enlarged,  thyroid.

Poultry

Sheep

General symptoms of poisoning:

Heinz bodies, hemoglobinuria.

Swine

General symptoms of poisoning:

Weight gain, reduced.

Notes on poisoning:

Glucosinolates in the plants can cause general reduced weight gain in young pigs (less than 20 kg) (Fenwick et al. 1989).