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.