Garlic (Allium sativum) extract inhibits lipopolysaccharide-induced toll-like receptor 4 dimerization

Hyung Sun Youn, Hyo Jin Lim, Hwa Jin Lee, Daniel Hwang, Mihi Yang, Raok Jeon, Jae Ha Ryu

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


Garlic has long been used as a folk medicine. Numerous studies have demonstrated that a garlic extract and its sulfur-containing compounds inhibited nuclear factor kappa B (NF-κB) activation induced by various receptor agonists including lipopolysaccharide (LPS). Toll-like receptors (TLRs) play a key role in sensing diverse microbial products and inducing innate immune responses. The dimerization of TLR4 is required for the activation of downstream signaling pathways, including NF-κB. Therefore, TLR4 dimerization may be one of the first lines of regulation in activating LPS-induced signaling pathways. We report here biochemical evidence that the ethyl acetate fraction of garlic inhibited the LPS-induced dimerization of TLR4, resulting in the inhibition of NF-κB activation and the expression of cyclooxygenase 2 and inducible nitric oxide synthase. Our results demonstrate for the first time that a garlic extract can directly inhibit the TLRs-mediated signaling pathway at the receptor level. These results shed a new insight into understanding how garlic modulates the immune responses that could modify the risk of many chronic diseases.

Original languageEnglish (US)
Pages (from-to)368-375
Number of pages8
JournalBioscience, Biotechnology and Biochemistry
Issue number2
StatePublished - 2008


  • Cyclooxygenase
  • Garlic
  • Nitric oxide synthase
  • Toll-like receptor

ASJC Scopus subject areas

  • Bioengineering
  • Biotechnology
  • Biochemistry
  • Biochemistry, Genetics and Molecular Biology(all)
  • Chemistry (miscellaneous)
  • Applied Microbiology and Biotechnology
  • Food Science


Dive into the research topics of 'Garlic (Allium sativum) extract inhibits lipopolysaccharide-induced toll-like receptor 4 dimerization'. Together they form a unique fingerprint.

Cite this