Bioactive Compounds of Garlic and Their Therapeutic Applications

Garlic (Allium sativum) is distinguished by a suite of sulphur-containing bioactives, chief among them allicin, alliin and related thiosulfinates, together with water-soluble organosulphur compounds such as S-allyl-cysteine. These constituents exert potent antioxidant, anti-inflammatory and antimicrobial effects through mechanisms including modulation of redox signalling, inhibition of pro-inflammatory transcription factors and selective reactivity with thiol groups in proteins and glutathione. Clinical and preclinical studies have demonstrated cardiovascular benefits via lipid-lowering and vasodilatory actions, immunomodulatory effects through cytokine regulation, neuroprotection by activation of endogenous antioxidant pathways, and anticancer potential owing to cell-cycle arrest and apoptosis induction. Preparative forms such as aged garlic extract and black garlic enrich certain bioactives while reducing pungency, broadening practical applications in nutraceuticals, functional foods and adjuvant therapies.

Research from Nature Portfolio

Advances in the design of allicin analogues have illuminated structure–activity relationships critical to antimicrobial efficacy and thermal stability. By synthesising a series of dialkyl thiosulfinates and assessing their activity against bacterial and fungal pathogens, researchers have shown that subtle modifications of the thiosulfinate moiety can enhance volatility, extend shelf life and retain potency against resistant strains. Chemogenetic screening in yeast models confirmed that resistance mechanisms centre on glutathione homeostasis, underscoring the importance of redox balance for therapeutic utility. These findings chart a path towards novel sulfinyl-based antimicrobials for medical and agricultural applications.

Bioactive Compounds of Garlic and Their Therapeutic Applications publication trend

The graph below shows the total number of articles in bioactive compounds of garlic and their therapeutic applications across all publications each year (not limited to Nature Index journals).

Technical terms

Allicin: A reactive thiosulfinate formed enzymatically from alliin, responsible for many of garlic’s antimicrobial and antioxidant activities.

Alliin: S-allyl-L-cysteine sulfoxide, the non-odorous precursor converted to allicin by alliinase upon tissue damage.

Thiosulfinate: A functional group (R–S(=O)–S–R) characteristic of allicin and its analogues, mediating redox interactions with thiols.

Reactive sulphur species (RSS): Biologically active sulphur-containing molecules that modulate redox signalling and cellular defence systems.

Nrf2: A transcription factor that orchestrates the expression of antioxidant and phase II detoxification enzymes in response to oxidative stress.

NF-κB: A transcription factor central to pro-inflammatory gene expression, which can be inhibited by garlic-derived sulphur compounds.

References

1. Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.). Foods (2019).
2. Chemical Constituents and Pharmacological Activities of Garlic (Allium sativum L.): A Review. Nutrients (2020).
3. Allicin: Chemistry and Biological Properties. Molecules (2014).
4. Immunomodulation and Anti‐Inflammatory Effects of Garlic Compounds. Journal of Immunology Research (2015).
5. The Antioxidant Mechanisms Underlying the Aged Garlic Extract‐ and S‐Allylcysteine‐Induced Protection. Oxidative Medicine and Cellular Longevity (2012).
6. Physicochemical and Antioxidant Properties of Black Garlic. Molecules (2014).
7. Effect of garlic on cardiovascular disorders: a review. Nutrition Journal (2002).
8. A Comparison of the Antibacterial and Antifungal Activities of Thiosulfinate Analogues of Allicin. Scientific Reports (2018).
9. Allicin Induces Thiol Stress in Bacteria through S-Allylmercapto Modification of Protein Cysteines. Journal of Biological Chemistry (2016).