Mechanism of Action & 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
• Dried bulb
• As food: Juice, syrup etc.
• Topical: poultice, ear/nasal drops

Safety & Toxicity Concerns:

• 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.
• 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.