Heliotropium indicum 大尾搖

Boraginaceae 紫草科

Wild Heliotropium, Indian Heliotrope1

狗尾草、貓尾草、象鼻草2

POISONOUS PARTS

Whole plant.3,4

TOXICITY

  • Toxic Constituents  
    Pyrrolizidine alkaloids such as indicine, acetylindicine and indicinine.2,4–6
  • Toxic Dose  
    Long-term consumption of 1 mg pyrrolizidine alkaloids per day can be toxic.7
  • Mechanism  
    Pyrrolizidine alkaloids are converted into highly reactive metabolites after transformation in the liver by the cytochrome P450 system. These metabolites bind to proteins, DNA and RNA, and induce acute and chronic toxicities. Liver is the major organ affected, and veno-occlusive disease (Budd-Chiari syndrome) could occur. As liver metabolism is involved, toxicity is not strictly dose-dependent but shows individual variability.8,9
  • Poisoning Features  
    Pyrrolizidine alkaloid poisoning has acute and chronic effects. Acute: abdominal pain, hepatomegaly, ascites, liver necrosis and even death. Chronic: hepatomegaly, recurrent ascites, hepatic vein occlusion (Budd-Chiari syndrome), cirrhosis, hepatocellular carcinoma, pulmonary hypertension and even death.7,8
  • Poisoning Events  
    There were 2 main sources of pyrrolizidine alkaloid poisoning. The consumption of cereal grains contaminated by the toxic weeds had caused numerous poisoning in many countries. In Afghanistan alone, an estimated 8000 people were affected with more than 1600 deaths. The other source is the use of pyrrolizidine alkaloid-containing herbs for medicinal and dietary purposes, leading to poisoning in all parts of the world.7,8

CLINICAL MANAGEMENT

Supportive treatment. Early diagnosis and avoidance of further exposure to the toxins is important.9

IDENTIFICATION FEATURES

Annual herbs, 20–50 cm tall. Stems strigose. Leaves alternate or subopposite; leaf blades 3–9 × 2–4 cm, margin undulate, pubescent or strigose on both surfaces. Cymes solitary, 5–15 cm long, scorpioid. Corolla light blue or blue‑purple, 3–4 mm long, salverform; limb 2–2.5 mm wide; lobes suborbicular, about 1 mm wide, margin crispate. Fruits 3–3.5 mm long, ribbed.10

MEDICINAL USES

Whole plant or roots used in TCM: clear heat and remove toxin, disperse swelling, induce diuresis. Recommended dose: 15–30 g.2,11

LABORATORY ANALYSIS

Indicine and acetylindicine can be detected by GC-MS and LC-MS/MS.12–14