Garlic possesses antioxidant properties that show potential in aiding the treatment of liver-related conditions induced by alcohol consumption, although its efficacy in this regard may be limited. Markers indicating liver function and health, such as ALT (Alanine transaminase), AST (Aspartate transaminase) and ALP (Alkaline phosphatase) enzymes, were influenced in studies involving garlic administration.

In experiments where lead was administered, it led to a notable increase in plasma ALT and ALP activities while reducing plasma AST activity. However, garlic intake significantly decreased ALT and ALP activities while increasing AST activity. In rat studies, both aged garlic and garlic diallyl sulfur compounds demonstrated protective effects against liver damage caused by certain chemicals. Additionally, aged-garlic extracts were found to mitigate the effects of aflatoxin B1 mutagenesis, reducing the production and activation of liver carcinogenic nitrosamines.

Anti-inflammatory Quality of Garlic

The anti-inflammatory effects observed were linked to a decrease in the expression and generation of proinflammatory cytokines like TNF (Tumfactor-alpha factor alpha) and IL-1 (Interleukin-1). This reduction in proinflammatory cytokines can be attributed to the presence of bioactive components found in garlic.

Compounds like diallyl sulfide, known for inhibiting TNF and IL-1 secretion, and allyl methyl sulfide, which stimulates the production of anti-inflammatory cytokines like IL-10, are believed to be responsible for regulating the levels of proinflammatory and anti-inflammatory cytokines in the colon when treated with garlic oil.

Cardiovascular Quality of Garlic

Consuming garlic yields various cardiovascular benefits, including lowering blood pressure, hindering atherosclerosis, reducing serum cholesterol and triglycerides, and suppressing platelet aggregation. Additionally, garlic enhances fibrinolytic activity, among other positive effects.

Garlic’s impact on cardiovascular health stems from its ability to inhibit the formation of 3-hydroxy-3-methylglutaryl-CoA, ultimately lowering cholesterol levels. Studies have indicated that garlic diminishes LDL oxidation, arterial plaque development, and platelet aggregation. It also contributes to decreasing homocysteine levels, blood pressure, and enhancing microcirculation, all vital aspects in managing diabetes.

Furthermore, garlic exhibits potential in preventing cognitive decline by shielding neurons from neurotoxicity and apoptosis, which plays a role in averting conditions like ischemia and obsessive-compulsive disorder (OCD). Additionally, it aids in preventing neuronal death while bolstering learning and memory retention.

Hyperlipidemia Quality of Garlic

Garlic demonstrated its ability to hinder liver fat production and enzymes responsible for cholesterol synthesis like malic acid synthetase, fatty acid synthetase, glucose-6-phosphate dehydrogenase, and 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase.

Studies conducted in vitro indicate that water-soluble organosulfur compounds such as S-allyl cysteine (SAC) in mature garlic extract and diallyl disulfide (DADS) in garlic oil effectively inhibit cholesterol formation. These compounds play a role in reducing plaque formation by lowering cholesterol and decreasing lipid peroxidation.

Furthermore, in vitro investigations suggest that garlic can suppress low-density lipoproteins (LDL) and increase their resistance to oxidation, contributing to potential benefits in preventing plaque buildup.

Antibacterial Quality of Garlic

Garlic extract displays inhibitory effects on various types of bacteria, including both Gram-positive and Gram-negative strains such as Staphylococcus, Streptococcus, Micrococcus, Enterobacter, Escherichia, Klebsiella, Lactobacillus, Pseudomonas, Shigella, Salmonella, Proteus, and Helicobacter pylori.

The active component responsible for this inhibition in garlic extracts is allicin, which is activated by enzymes like alliinase.

Antiviral Quality of Garlic

Garlic and its sulfur compounds have demonstrated effectiveness against various viruses including coxsackievirus spp., herpes simplex virus types 1 and 2, influenza B, parainfluenza virus type 3, vaccinia virus, vesicular stomatitis virus, human immunodeficiency virus type 1, and human rhinovirus type 2.

In terms of their virucidal effects, the sequence generally observed was: ajoene > allicin > allyl methyl thiosulfinate > methyl allyl thiosulfinate > methyl allyl.

Antifungal Quality of Garlic

Both the water-based garlic extract and the concentrated garlic oil exhibited inhibitory effects against Aspergillus. Allicin, a component of garlic, demonstrated fungicidal effects against various yeasts and fungi, including Candida albicans, Cryptococcus trichophyton, Histoplasma capsulatum, and Cryptococcus neoformans. Garlic has demonstrated the ability to impede the growth of fungal diseases.

Anticancer Quality of Garlic

The research investigated garlic’s impact on cell lines associated with leukemia, melanoma, and neuroblastoma. Allyl sulfides contribute to garlic’s distinct flavor. These compounds have shown in experimental studies to inhibit both the initial and promotional stages of tumorous growth in various cancers.

Interestingly, individuals who consumed higher quantities of garlic exhibited a 54% lower risk of pancreatic cancer compared to those consuming less garlic. Various forms of garlic supplements, including fresh garlic extract, aged garlic, garlic oil, and different organosulfur compounds derived from garlic, have demonstrated potential in preventing cancer. This preventive effect is attributed to the presence of organosulfur compounds in garlic.

Studies have revealed that aged garlic extract exhibits free radical scavenging activity, unlike fresh garlic extract. Components like S-allyl cysteine and S-allyl mercapto-L-cysteine, prevalent in aged garlic, display significant free radical scavenging abilities. Moreover, multiple organosulfur compounds derived from garlic, including acetylcysteine, have demonstrated the ability to slow the growth of chemically induced and transplantable cancers in various animal studies.

Conclusion

Garlic’s primary active component, allicin, and its derivatives hold substantial nutritional and medicinal value globally. It serves as a plentiful and safe source of biologically active compounds with low toxicity. Throughout history, all parts of the garlic plant have found use in various culinary dishes like sausages and salads, as well as in traditional medicine. The plant’s therapeutic advantages stem from its rich concentration of sulfur compounds. Hence, further pharmacological research is necessary to fully understand and harness its potential in enhancing human health.