Garlic (Allium sativum L.) is a plant belonging to the Alliaceae family. It is widely produced and used worldwide. The importance of garlic as a spice has been known since ancient times, and its medicinal use is also common among the public. In recent years, many studies have been conducted revealing the medicinal value of garlic, and the data obtained from these studies have revealed its importance in terms of both alternative, complementary medicine and traditional medicine approaches in the treatment of various diseases (1-6).
Compounds:
Garlic contains high amounts of organosulfur compounds. Among these, the ones in the highest concentration are; allicin, diallyl thiosulfonate (allicin), diallyl sulfide (DAS), diallyl disulfide (DADS), diallyl trisulfide (DATS), N-acetylcysteine (NAC) and S-allyl cysteine (SAC). These compounds have been shown to be responsible for the therapeutic value of garlic (7-9). N-acetylcysteine, one of these compounds, is still used in medicine as a mucolytic and as a liver protector in paracetamol poisoning. Garlic is rich in organosulfur compounds as well as peptides, steroids, terpenoids, flavonoids, saponins and phenols. Garlic also contains selenium, fructose, glucose and galactose (7-9).
Therapeutic Value:
Due to the organosulfur compounds, it has been investigated in various studies that garlic has an effect on hypertension (10,11), diabetes, hyperlipidemia and coronary artery disease (10-15), colon, rectal, stomach, breast, prostate and bladder, and lung cancers (16-18). In addition, it is also used among the public for colds and flu. It is also known that garlic has antioxidant, neuroprotective, antibacterial and immune system-supporting properties (19-22). Since garlic also has analgesic (antinociceptive) and anti-inflammatory effects, it shows promise in the treatment of diseases such as knee osteoarthritis (calcification) and rheumatoid arthritis (rheumatism) in humans. Studies conducted on people with knee osteoarthritis have shown that garlic supplements have a positive effect (23-26). It has been reported that it reduces the severity of pain in these patients, especially according to the visual analog scale (VAS) and McMaster Universities Osteoarthritis Index (WOMAC). Similar positive results have also been shown in rheumatoid arthritis patients (27). Oxidative stress plays an important role in the pathogenesis of rheumatoid arthritis (28). Excessive production of reactive oxygen species (ROS) can damage proteins, lipids, nucleic acids, and matrix components (29). The antioxidant properties of garlic may contribute to pain relief in patients with rheumatoid arthritis. Moosavian et al. (2020) showed that daily consumption of two garlic powder tablets (500 mg) for 8 weeks in women with rheumatoid arthritis reduced MDA levels and increased total antioxidant capacity, thus reducing pain measured by VAS (30).
References:
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23. Dehghani, S., Alipoor, E., Salimzadeh, A., Yaseri, M., Hosseini, M., Feinle-Bisset, C., & Hosseinzadeh-Attar, M. J. (2018). The effect of a garlic supplement on the pro-inflammatory adipocytokines, resistin and tumor necrosis factor-alpha, and on pain severity, in overweight or obese women with knee osteoarthritis. Phytomedicine, 48, 70-75.
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30. Moosavian, S.P., Paknahad, Z., & Habibagahi, Z. (2020). A randomized, double-blind, placebo-controlled clinical trial, evaluating the garlic supplement effects on some serum biomarkers of oxidative stress, and quality of life in women with rheumatoid arthritis. International Journal of Clinical Practice, 74, e13498. https://doi.org/10.1111/ijcp.13498