Originally from Central Asia or the Caucasus, garlic ( Allium sativum ) has been cultivated and consumed for over 6,000 years. It has always been considered a panacea. In ancient Rome, Pliny the Elder counted 61 diseases cured by garlic. Before the discovery of antibiotics , crushed garlic cloves were used, among other things, as an antiseptic in the treatment of wounds.
A little history
In Egypt, from the time of the pharaohs, we notice the nutritive properties of garlic. The Greek historian Herodotus thus reports that the laborers employed in the construction of the pyramids received a daily ration of garlic to give them the strength necessary for this exhausting work. Cheops even had the image engraved inside his pyramid. It is also used for mummifications, against snakebites and accompanies the deceased in the afterlife. The Greeks also knew the virtues of garlic. The athletes who participated in the Olympic Games munched a pod before the effort.
For the Romans, according to Virgil , garlic was a suitable food to support the forces of the reapers . The Gauls also consumed a great deal of it. Later, Louis the Pious , son of Charlemagne, ordered the cultivation of garlic in the royal gardens. But it is especially under the reign of Henri IV (1553-1610) that garlic will know its letters of nobility. The grandfather of the future king rubs the lips of the newborn with a clove of garlic to protect him from harm and give him the strength of the chef, thus respecting a Béarn tradition.
Homer , 850 years before Jesus Christ, insisted on the medicinal virtues of garlic. Hippocrates , Aristophanes and Aristotle extensively praised the merits of garlic, a symbol of physical strength. In fact, garlic is a real “ food ” combining the virtues of a food and a medicine. It was also the famous “theriac of the peasants” of Galen !
Probably having migrated from the steppes of Central Asia in prehistoric times , it has been cultivated for over 6,000 years. Particularly popular with the Egyptians, they elevated him to the rank of deity.
What are the pharmacological properties of garlic bulb essential oil ?
The bactericidal, fungicidal (anti-candidal), intestinal antiparasitic (anthelmintic: roundworm, pinworm, tænia) properties of diallyl sulfide and other organosulfur compounds, main constituents of garlic, have been demonstrated. The antimicrobial effect of diallyl sulfide was more particularly shown on Campylobacter jejuni , through inhibition of the bacterial biofilm.
Anti-infectious and antibacterial, garlic essential oil also acts effectively in respiratory infections , due to its passage through the lungs during its partial elimination. This oil is particularly known to inhibit the growth of Staphylococcus aureus resistant to methicillin ( diallyl sulfide and diallyl disulfide ).
Anti hypertensive, with vasodilating activity of capillary arterioles according to Loeper ; Garlic essential oil also slows down the pulse . This repeatedly described activity is due to its diuretic properties, inhibition of angiotensin converting enzyme and vasodilation of blood vessels.
Anti-platelet aggregation, it increases fibrinolytic activity and prevents the appearance of infarction.
Anticholesterolemic by reduction of the plasma level of lipids demonstrated by numerous clinical studies carried out in double blind against placebo, the essential oil of garlic exerts in fact an antidiabetic effect , which passes by a significant lowering of the glycemia, the serum cholesterol , triglycerides, erythrocyte glycated hemoglobin, and renal and hepatic peroxidation.
Anti hepatotoxic, garlic essential oil stimulates the biosynthesis of liver phase II detoxification enzymes, especially DATS, and increases the activity of glutathione-S-transferase; which therefore protects the function and integrity of the hepatic mitochondria. In addition, garlic activates the synthesis of constituent androstane receptors which are associated with the detoxification of liver cells exposed to xenobiotics such as estrogen.
Garlic inhibits acetaminophen-induced toxicity. It limits the risk associated with poisoning by heavy metals and solvents . The diallyl sulfide , a major constituent of garlic, is an inhibitor of CYP2E1, and plays a role in preventing cell vis-à-vis alcohol, analgesics, xenobiotics and in diseases such as HIV and diabetes.
The essential oil of garlic would prevent against the formation of malignant tumors, in particular on the level of the stomach and the esophagus (Chinese and Japanese studies). It is also of interest in the chemoprevention of cancers , stops the division of hepatic tumor cells (G2 / M phase of the cell cycle), and induces apoptosis in lung cancers.
Garlic is a digestive tonic that stimulates the appetite (often compared to cinchona ). It is also antispasmodic and antiputrid. Molecular docking studies show that organosulfur compounds in garlic (especially diallyl sulfide and triallyl sulfide ) have anti-coronavirus SARS-CoV-2 activity .
Hormon-like (light thyroid stimulating and cortison-like), this essential oil is a glandular rebalancing agent . It is also effective against warts, corns and calluses, in local application.
Does garlic essential oil require precautions for use?
- This oil contains sulfur
- Poor gastric tolerance at high doses
- Caution in case of hypothyroidism
- Dermocaustic essential oil, dilute to a maximum of 20% in a fatty substance
- Do not distribute
- Contraindicated in pregnant or breastfeeding women
- Reserved for adults
- No prolonged use
- Avoid eye contact
- Avoid in combination with cortisone, risk of drug interaction
- Do not use over a prolonged period, at the risk of resting the pituitary-adrenal axis and suffering from acute adrenal insufficiency when stopping the intake of essential oil
- Avoid applying the essential oil in the evening (or before any rest period)
- Not recommended for people with osteoporosis , due to the inherent risk of decalcification
Pharmacokinetic interactions :
- No significant effect on CYP1A2, CYP2D6 and CYP3A4 activity, but significant decrease in CYP2E1 activity acting on alcohol metabolism (Garlic is classified as non-inhibitor of CYP3A4)
- CYP 2C9 inhibitor
- Interactions with drugs used against HIV ( saquinavir, ritonavir )
Pharmacodynamic interactions :
- Theoretical risk of variation in the effect of certain anti-diabetic drugs (additive effect)
- Interactions with Aspirin, oral anticoagulants, warfarin and non-steroidal anti-inflammatory drugs (risk of bleeding)
- Discontinue consumption of garlic supplements at least 7 days before surgery
Medical bibliographic sources and clinical trials :
- Thuy, B., My, T., Hai, N., Hieu, LT., Hoa, TT, Thi Phuong Loan, H., Triet, NT., Anh, T., Quy, PT, Tat, PV, Hue , NV, Quang, DT, Trung, NT, Tung, VT., Huynh, LK, & Nhung, N. (2020). Investigation into SARS-CoV-2 Resistance of Compounds in Garlic Essential Oil. ACS omega
- Campbell, CJ (2009). Analyzes of essential and edible oils, and constituents therein, as candidate repellents for the yellow fever mosquito Aedes aegypti L. (Diptera: Culicidae) (Doctoral dissertation, Dept. of Biological Sciences-Simon Fraser University)
- Zadoyan G, Fuhr U. Phenotyping studies to assess the effects of phytopharmaceuticals on in vivo activity of main human cytochrome p450 enzymes. Planta Med. 2012
- Engdal S, Nilsen OG. In vitro inhibition of CYP3A4 by herbal remedies frequently used by cancer patients. Phytother Res. 2009
- Ho, BE, Shen, DD, McCune, JS, Bui, T., Risler, L., Yang, Z., & Ho, RJ (2010). Effects of Garlic on Cytochromes P450 2C9- and 3A4-Mediated Drug Metabolism in Human Hepatocytes. Scientia pharmaceutica
- Gallicano, K., Foster, B., & Choudhri, S. (2003). Effect of short-term administration of garlic supplements on single-dose ritonavir pharmacokinetics in healthy volunteers. British journal of clinical pharmacology
- Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm. 2000
- AFSOS Francophone Association for Supportive Oncological Care
- Low CF et al., Inhibition oh hyphae formation and SIR2 expression in Candida albicans treated with fresh Allium sativum (garlic) extract, J Appl Microbiol., 2008
- Ried K. et al., Effect of garlic on blood pressure: a systematic review and meta-analysis, BMC Cardiovasc Disord., 2008
- Ezeala C. et al., Fresh Garlic Extract Protects The Liver Against Acetaminophen-Induced Toxicity, The Internet Journal of Nutrition and Wellness, 2008