Allium sativum
Allium sativum
Common Name: Garlic
Family: Liliaceae
Part used: Bulb
Constituents:
- Volatile oil (sulfur containing compounds): sulfoxides (ajoene, alliin, allicin) & thiocyanates
- Enzymes (allinase)
- Nutrients: Carbohydrates, lipids & amino acids
- Lectins (lectin-allinase complexes)
Medical actions:
- Anti-microbial
- Antispasmodic & Carminative
- Anti-thrombotic (Anti-platelet aggregant)
- Cardioprotective
- Diaphoretic
- Expectorant
- Hepatoprotective
- Hypoglycemic
- Hypolipidemic
- Hypotensive
- Rubefacient
Medical uses:
- Historical use is recorded by many physicians and herbalists of the ancient world. Was recommended as an antiseptic, an antidote for poisonous bites, as a cough suppressant, and to expel intestinal parasites. Considered a good carminative for digestive problems and an excellent treatment for diarrhea, especially when due to infectious causes, bacterial, fungal and viral infections.
Pharmacology:
- VO & sulfur containing compounds (alliin & allicin) are largely responsible for effects.
- Alliin is converted by allinase to alliicin when chopped, crushed and exposed to air (oxidized).
- Allicin inhibits platelet aggregation, reduces cholesterol, and is antimicrobial and antioxidant.
- Anti-thrombotic activity may be in part due to inhibition of thromboxane B2 synthesis, and anti-platelet activity is associated with allicin, ajoene, and sulfides.
- Hepatoprotective possibly due to s-allyl components and prevention of glutathione depletion.
Pharmacy:
- Fresh bulb: 1 clove eaten daily for prophylaxis. During acute infections, 1 clove TID. Note: Allow bulb to oxidize 1-3 min before ingesting for best effect.
- Dried bulb: 2-4 g BID or 12:1 extract, 300 mg (standardized to 12 mg allicin), BID.
- As food: Juice, syrup etc.
- Topical: poultice, ear/nasal drops.
Toxicity:
- Can cause irritation to the gastric mucosa (especially fresh bulb). Avoid in acute stomach inflammation, acid reflux or irritation of mucosal surfaces.
- High doses can cause breath & body odour.
Contraindications:
- Do not use within 10 days of surgery or with medications that inhibit blood coagulation.
- Avoid excessive use in early pregnancy due to potential emmenagogue effects, and hypothyroidism as may cause reduced iodine uptake by the thyroid (theoretical).
- Hypersensitivity (eg. allergy) has been known to occur.
Interactions:
- May potentiate insulin (inhibits its breakdown) and hypoglycemic drugs.
- May potentiate anticoagulants and increase bleeding time (eg. Aspirin, clopidogrel, warfarin) due to antiplatelet activity (theoretical). Monitor at doses equivalent to ≥ 3 g/day fresh garlic (low level of risk).
- May enhance effects of cholesterol-lowering agents (theoretical).
- May decrease drug level of HIV protease inhibitors.
References:
- Find a complete list of references for this monograph as well as images and a review of its evidence based applications in Dr. Marciano’s Herbal Textbook.