Plant-based poisoning, particularly from toxic mushrooms and mycotoxins, is a significant public health concern. Mushrooms contain a wide range of toxins causing gastrointestinal, neurological, renal, and hepatic manifestations. Mycotoxins, produced from contaminated food grains, can lead to chronic toxicity, cancer, and organ failure. Understanding the toxic mechanisms and appropriate management is essential in clinical toxicology.
Mushroom Poisoning
Mushroom toxicity varies widely depending on the species and toxin involved. Poisonous mushrooms can be broadly categorized based on their toxic effects.
1. Amanita Phalloides (Death Cap Mushroom)
Responsible for most fatal mushroom poisonings due to amatoxins.
Mechanism
- Inhibits RNA polymerase II
- Blocks protein synthesis
- Causes massive hepatocellular necrosis
Clinical Features
- Delayed onset (6–24 hours)
- Severe vomiting and diarrhea
- Dehydration and electrolyte imbalance
- Hepatic failure: jaundice, bleeding tendencies
- Renal failure in advanced toxicity
Management
- Aggressive rehydration
- Activated charcoal (multiple doses)
- Silibinin and N-acetylcysteine (if available)
- Monitor LFTs and renal function
- Liver transplant in severe cases
2. Gyromitra Species
Mechanism
- Contains gyromitrin → converted to monomethylhydrazine (MMH)
- Interferes with GABA synthesis
Symptoms
- Nausea, vomiting
- Seizures
- Hepatic dysfunction
Management
- Pyridoxine (Vitamin B6) for seizures
- Supportive care and hydration
3. Psilocybin Mushrooms (“Magic Mushrooms”)
Mechanism
Acts on serotonin receptors (5-HT2A), causing hallucinations.
Symptoms
- Euphoria
- Visual hallucinations
- Agitation and confusion
- Tachycardia and hypertension
Management
- Reassurance and observation
- Benzodiazepines for agitation
4. Muscarine-Containing Mushrooms
Mechanism
Stimulates muscarinic receptors.
Symptoms
- Salivation, lacrimation
- Bradycardia
- Bronchospasm
- Diarrhea
Management
- Atropine for severe muscarinic symptoms
Mycotoxins
Mycotoxins are toxic secondary metabolites produced by fungi contaminating food grains, nuts, and stored crops. Chronic exposure leads to significant systemic toxicity.
Types of Mycotoxins
- Aflatoxins (Aspergillus species)
- Ochratoxins
- Trichothecenes
- Fumonisins
Aflatoxin (Most Common Mycotoxin)
Sources
- Contaminated peanuts
- Corn and grains stored in humid conditions
Mechanism
- Forms DNA adducts → mutagenic
- Causes oxidative stress
- Leads to hepatocellular carcinoma
Clinical Features
- Chronic liver injury
- Jaundice
- Weight loss
- Increased risk of liver cancer
Management
- Remove contaminated food
- Supportive liver care
- Nutritional supplementation
Trichothecene Mycotoxins
Mechanism
Inhibits protein synthesis and damages rapidly dividing cells.
Symptoms
- Skin irritation
- Nausea and vomiting
- Bone marrow suppression
Management
- Supportive therapy
- Hematological monitoring
Fumonisins
Sources
- Contaminated corn
Health Effects
- Esophageal cancer
- Liver toxicity
General Management Principles
- Identify and eliminate exposure source
- Provide supportive care (fluids, electrolytes)
- Activated charcoal in early mushroom ingestion
- Monitor liver and kidney function
- Use specific antidotes when available (e.g., pyridoxine)
Detailed Notes:
For PDF style full-color notes, open the complete study material below:
PATH: PHARMD/ PHARMD NOTES/ PHARMD FOURTH YEAR NOTES/ CLINICAL TOXICOLOGY/ PLANTS POISONING: MUSHROOMS, MYCOTOXINS.