Garlic (Allium sativum) is a sulfur-containing plant consumed worldwide, both as a food and as a support of human health. Modern research indicates garlic may have a supportive role in cardiovascular health, in the body’s response to pathogenic microbes, and for healthy cellular function. It may also support healthy lipid metabolism and the body’s response to oxidative stress.

Garlic contains many health-supportive constituents, including allicin, along with flavonoids that include quercetin and ajoene. The bioactive constituents of garlic have been shown to support cellular health through their ability to influence lipid peroxidation, nitric oxide synthetase, and nuclear factor-kappa B (NF-κB). Some components of garlic, such as allicin, can be unstable, but ajoene is reported to be both biologically active and more stable.

Ajoene may be partially responsible for the potential role of garlic to support a normal response to pathogenic microbes. An animal study assessed the efficacy of supplementation with garlic on murine populations infected with influenza viruses. Improvements in the production of neutralizing antibodies were shown to occur in the presence of several phytochemicals in garlic, including ajoene.

Ajoene has also been shown in studies to disrupt the quorum sensing of certain pathogenic bacteria, including Pseudomonas aeruginosa (P. aeruginosa). It may also help to inhibit the biofilm formed by certain bacteria including P. aeruginosa. Ajoene and its derivatives have also been shown to exhibit activity in the presence of certain gram-positive and gram-negative bacteria, such as the Mycobacterium genus.

In laboratory studies, ajoene has also been shown to support cellular health. It has been shown to attenuate the growth of certain cancer cell lines. Ajoene was also shown to modulate certain caspase activity, peroxide production, and apoptosis of certain cancer cells in another study.

A mechanism of action believed to be responsible for the supportive role of ajoene is its disulfide structure and its ability to interact with thiol residues. Derivatives of ajoene have also been shown to support cellular health. One derivative, SPA3015, has been shown to suppress NF-κB signaling and modulate certain anti-apoptotic proteins. Other ajoene derivatives have been shown to inhibit the proliferation of certain cultured cancer cells.

Many aspects of the influence of garlic on human health have been elucidated by modern research. Garlic has been shown to support cardiovascular health, cellular function, and lipid metabolism. Although there is much to explore in future research, ajoene, a bioactive component of garlic, may also support many aspects of human health.

By Colleen Ambrose, ND, MAT