Ricinus communis 蓖麻

POISONOUS PARTS

Whole plant, especially the seeds.³

TOXICITY

• Toxic Constituents

  Ricin.^4,5

• Toxic Dose

  Reported lethal dose: 1 bean chewed and swallowed. As the seed coat is not easily digested, the toxicity is lower when the seeds are swallowed whole.⁶

• Mechanism

  Ricin inactivates ribosome and hence inhibits protein synthesis.^7–9

• Poisoning Features

  Nausea, vomiting, diarrhoea and abdominal pain; followed by hypotension, liver impairment, renal impairment, multi-organ failure and even death.⁵

• Poisoning Events

  Multiple poisoning cases due to either accidental or suicidal ingestion of the seeds have been reported worldwide. Accidental ingestions are more common in children. Many patients recovered with intensive care support, though fatalities have been reported. Parenteral injection of seed extracts as a mean of suicide and murder has also been reported.^5,6

CLINICAL MANAGEMENT

Supportive treatment.

IDENTIFICATION FEATURES

Shrubs, up to 5 m tall. Leaves alternate; petioles 3.5–50 cm long; leaf blades 10–65 × 10–75 cm, palmately 7–11-lobed, margin serrate. Racemes or panicles terminal, 15–30 cm long. Male flowers staminal fascicles many. Female flowers styles red, about 4 mm long. Capsules 1.5–2.5 cm long, softly echinate or tuberculate. Seeds 8–18 mm long, ellipsoidal, variously marked and colored.¹⁰

MEDICINAL USES

Highly toxic; use with caution. Uses in TCM—seeds: unblock the collaterals, disperse swelling and draw out toxin, induce purgation and unblock stagnation; extracted seed oil: lubricate intestines, moisten the skin; roots: tranquilise mind and stop convulsions, dispel wind and dissipate stasis, activate blood and disperse swelling. Recommended dose: Seeds 2–5 g, extracted seed oil 10–20 mL, roots 15–30 g.^2,11–13

LABORATORY ANALYSIS

Ricinine, an alkaloid marker of R. communis, and ricin can be detected by LC-MS/MS.^14,15