Synonyms
Porvium sativum Rehb.

Local names
It is most commonly known as “garlic”. Ail, ail commun, ajo, akashneem, allium, alubosa elewe, ayo-ishi, ayu, banlasun, camphor of the poor, daitóan, dasuan, dawang, dra thiam, foom, Gartenlauch, hom khaao, hom kía, hom thiam, hua thiam, kesumphin, kitunguu-sumu, Knoblauch, kra thiam, krathiam, krathiam cheen, krathiam khaao, l’ail, lahsun, lai, lashun, lasan, lasun, lasuna, Lauch, lay, layi, lehsun, lesun, lobha, majo, naharu, nectar of the gods, ninniku, pa-se-waa, poor man’s treacle, rason, rasonam, rasun, rustic treacles, seer, skordo, sluôn, stinking rose, sudulunu, ta-suam, ta-suan, tafanuwa, tellagada, tellagaddalu, thiam, toi thum, tum, umbi bawang putih, vallaippundu, velluli, vellulli

Description
A perennial, erect bulbous herb, 30–60 cm tall, strong smelling when crushed. The underground portion consists of a compound bulb with numerous fibrous rootlets; the bulb gives rise above ground to a number of narrow, keeled, grasslike leaves. The leaf blade is linear, flat, solid, 1.0–2.5cm wide, 30–60 cm long, and has an acute apex. Leaf sheaths form a pseudostem. Inflorescences are umbellate; scape smooth, round, solid, and coiled at first, subtended by membraneous, long-beaked spathe, splitting on one side and remaining attached to umbel. Small bulbils are produced in inflorescences; flowers are variable in number and sometimes absent, seldom open and may wither in bud. Flowers are on slender pedicels; consisting of perianth of 6 segments, about 4–6mm long, pinkish; stamens 6, anthers exserted; ovary superior, 3-locular. Fruit is a small loculicidal capsule. Seeds are seldom if ever produced

Plant material used
fresh or dried bulbs

Chemical assays
Qualitative and quantitative assay for sulfur constituents (alliin, allicin etc.) content by means of high-performance liquid chromatography or gas chromatography–mass spectroscopy methods.

Major chemical constituents
The most important chemical constituents reported from Bulbus Allii Sativi are the sulfur compounds. It has been estimated that cysteine sulfoxides (e.g. alliin) and the non-volatile γ-glutamylcysteine peptides make up more than 82% of the total sulfur content of garlic. The thiosulfinates (e.g. allicin), ajoenes (e.g. E-ajoene, Z-ajoene), vinyldithiins (e.g. 2-vinyl-(4H)-1,3-dithiin, 3-vinyl-(4H)-1,2-dithiin), and sulfides (e.g. diallyl disulfide, diallyl trisulfide), however, are not naturally occurring compounds. Rather, they are degradation products from the naturally occurring cysteine sulfoxide, alliin. When the garlic bulb is crushed, minced, or otherwise processed, alliin is released from compartments and interacts with the enzyme alliinase in adjacent vacuoles. Hydrolysis and immediate condensation of the reactive intermediate (allylsulfenic acid) forms allicin. One milligram alliin is considered to be equivalent to 0.45 mg of allicin. Allicin itself is an unstable product and will undergo additional reactions to form other derivatives, depending on environmental and processing conditions). Extraction of garlic cloves with ethanol at <0°C gave alliin; extraction with ethanol and water at 25 °C led to allicin and no alliin; and steam distillation (100 °C) converted the alliin totally to diallyl sulfides. Sulfur chemical profiles of Bulbus Allii Sativi products reflected the processing procedure: bulb, mainly alliin, allicin; dry powder, mainly alliin, allicin; volatile oil, almost entirely diallyl sulfide, diallyl disulfide, diallyl trisulfide, and diallyl tetrasulfide; oil macerate, mainly 2-vinyl-[4H]-1,3-dithiin, 3- vinyl-[4H]-1,3-dithiin, E-ajoene, and Z-ajoene. The content of alliin was also affected by processing treatment: whole garlic cloves (fresh) contained 0.25–1.15% alliin, while material carefully dried under mild conditions contained 0.7–1.7% alliin. G-γ-glutamylcysteine peptides are not acted on by alliinase. On prolonged storage or during germination, these peptides are acted on by γ-glutamyl transpeptidase to form thiosulfinates.

Dosage forms
Fresh bulbs, dried powder, volatile oil, oil macerates, juice, aqueous or alcoholic extracts, aged garlic extracts (minced garlic that is incubated in aqueous alcohol (15–20%) for 20 months, then concentrated), and odourless garlic products (garlic products in which the alliinase has been inactivated by cooking; or in which chlorophyll has been added as a deodorant; or aged garlic preparations that have low concentrations of water-soluble sulfur compounds). The juice is the most unstable dosage form. Alliin and allicin decompose rapidly, and those products must be used promptly. Dried Bulbus Allii Sativi products should be stored in well-closed containers, protected from light, moisture, and elevated temperature.

Medicinal uses
Uses supported by clinical data
As an adjuvant to dietetic management in the treatment of hyperlipidaemia, and in the prevention of atherosclerotic (age-dependent) vascular changes. The drug may be useful in the treatment of mild hypertension.

Uses described in pharmacopoeias and well established documents
The treatment of respiratory and urinary tract infections, ringworm and rheumatic conditions. The herb has been used as a carminative in the treatment of dyspepsia).

Uses described in traditional medicine
As an aphrodisiac, antipyretic, diuretic, emmenagogue, expectorant, and sedative, to treat asthma and bronchitis, and to promote hair growth

Proven pharmacological activity
Animal studies
Antibacterial and antifungal, Anthelminthic, Antihyperlipidemic, Antihypertension, Platelet aggregation inhibitor, Antihyperglycemic, Anti-inflammation, Antispasmodic

Human studies
Carminative, Antihypertension, Antihyperlipidemic, Platelet aggregation inhibitor,

Contraindications
Bulbus Allii Sativi is contraindicated in patients with a known allergy to the drug. The level of safety for Bulbus Allii Sativi is reflected by its worldwide use as a seasoning in food.

Warnings
Consumption of large amounts of garlic may increase the risk of postoperative bleeding.

Precautions
Drug interactions
Patients on warfarin therapy should be warned that garlic supplements may increase bleeding times. Blood clotting times have been reported to double in patients taking warfarin and garlic supplements

Carcinogenesis, mutagenesis, impairment of fertility
Bulbus Allii Sativi is not mutagenic in vitro (Salmonella microsome reversion assay and Escherichia coli).

Pregnancy: non-teratogenic effects
There are no objections to the use of Bulbus Allii Sativi during pregnancy and lactation.

Nursing mothers
Excretion of the components of Bulbus Allii Sativi into breast milk and its effect on the newborn has not been established.

Other precautions
No general precautions have been reported, and no precautions have been reported concerning drug and laboratory test interactions, paediatric use, or teratogenic or non-teratogenic effects on pregnancy.

Adverse reactions
Bulbus Allii Sativi has been reported to evoke occasional allergic reactions such as contact dermatitis and asthmatic attacks after inhalation of the powdered drug. Those sensitive to garlic may also have a reaction to onion or tulip. Ingestion of fresh garlic bulbs, extracts, or oil on an empty stomach may occasionally cause heartburn, nausea, vomiting, and diarrhoea. Garlic odour from breath and skin may be perceptible. One case of spontaneous spinal epidural haematoma, which was associated with excessive ingestion of fresh garlic cloves, has been reported.

Posology
Unless otherwise prescribed, average daily dose is as follows: fresh garlic, 2–5g; dried powder, 0.4–1.2 g; oil, 2–5mg; extract, 300–1000mg (as solid material). Other preparations should correspond to 4–12mg of alliin or about 2–5mg of allicin). Bulbus Allii Sativi should be taken with food to prevent gastrointestinal upset.