Ranunculus sceleratus 石龍芮

POISONOUS PARTS

Whole plant, especially the sap and flowers.^3,4

TOXICITY

• Toxic Constituents

  Protoanemonin (also known as anemonol) and ranunculin.^2-5

• Mechanism

  Ranunculin is hydrolyzed into protoanemonin upon crushing of plant tissue. Protoanemonin is an irritant to skin, eyes and mucosal surface; it binds sulphydryl groups and disrupts disulphide bonds, leading to disruption of skin architecture and formation of bulla.⁶

• Poisoning Features

  Skin contact: irritant contact dermatitis. Ingestion: stomatitis, vomiting, diarrhoea, abdominal pain, dizziness, convulsion.^3,5,7

• Poisoning Events

  Cases of irritant contact dermatitis after external application of R. sceleratus as treatment for rheumatoid arthritis and knee pain have been reported in China.^8,9

CLINICAL MANAGEMENT

Supportive treatment. For skin exposure, affected area could be irrigated with water. Correction of fluid and electrolyte disturbances in patients with severe gastrointestinal symptoms.^3,7

IDENTIFICATION FEATURES

Annual herbs, 10–40 cm tall. Stems erect, glabrous or sparsely puberulent. Basal leaves simple, 1–4 × 1.5–5 cm, long petioled, 3-partite. Cauline leaves many; upper ones smaller, 3-divided. Cymes terminal, flowers 4–8 mm in diameter. Petals 5, yellow, about 3.5 mm long. Aggregate fruits 8–12 mm long; achenes obovoid, slightly compressed.¹⁰

MEDICINAL USES

Uses in TCM—whole plant: clear heat and remove toxin, disperse swelling and dissipate binds, relieve pain, control malaria; fruits: harmonise the stomach function, tonify kidney, improve vision, dispel wind-dampness. Recommended dose: whole plant 3–9 g, fruits 3–9 g.²

LABORATORY ANALYSIS

Protoanemonin and ranunculin can be detected by HPLC-DAD and LC-MS/MS respectively.¹¹