Garlic (Allium sativum L.) Modulates Cytokine Expression in Lipopolysaccharide-Activated Human Blood Thereby Inhibiting NF-κB Activity

Abstract

Garlic is proposed to have immunomodulatory and anti-inflammatory properties. This paper shows that garlic powder extracts (GPE) and single garlic metabolites modulate lipopolysaccharide (LPS)-induced cytokine levels in human whole blood. GPE-altered cytokine levels in human blood sample supernatants reduced nuclear factor (NF)-kappaB activity in human cells exposed to these samples. Pretreatment with GPE (100 mg/L) reduced LPS-induced production of proinflammatory cytokines interleukin (IL)-1beta from 15.7 +/- 5.1 to 6.2 +/- 1.2 micro g/L and tumor necrosis factor (TNF)-alpha from 8.8 +/- 2.4 to 3.9 +/- 0.8 micro g/L, respectively, whereas the expression of the anti-inflammatory cytokine IL-10 was unchanged. The garlic metabolite diallydisulfide (1-100 micro mol/L) also significantly reduced IL-1beta and TNF-alpha. Interestingly, exposure of human embryonic kidney cell line (HEK293) cells to GPE-treated blood sample supernatants (10 or 100 mg/L) reduced NF-kappaB activity compared with cells exposed to untreated blood supernatants as measured by a NF-kappaB-driven luciferase reporter gene assay. Blood samples treated with extract obtained from unfertilized garlic (100 mg/L) reduced NF-kappaB activity by 25%, whereas blood samples treated with sulfur-fertilized garlic extracts (100 mg/L) lowered NF-kappaB activity by 41%. In summary, garlic may indeed promote an anti-inflammatory environment by cytokine modulation in human blood that leads to an overall inhibition of NF-kappaB activity in the surrounding tissue.

Anti-Inflammatory Activity of Sulfur-Containing Compounds from Garlic

“…11 Garlic contains diverse organosulfur compounds such as S-allyl-l-cysteine, diallyl disulfide, diallyl trisulfide, ajoene, and allicin, which have potent antioxidative, antibacterial, antiviral, and anticancer properties. [11][12][13] The major watersoluble sulfur compound, S-allyl-l-cysteine, in garlic extract seems to have direct inhibitory effect on nuclear factor-jB (NF-jB) and indirect inhibitory effect on lipopolysaccharide (LPS)-induced IL-1b and TNF-a in human whole blood. 14,15 The lipid-soluble sulfur compounds allicin and diallyl disulfide also inhibit NF-jB and reduce the expression of inducible nitric oxide (NO) synthase (iNOS) in LPS-stimulated macrophages.…”

Garlic (Allium sativum) Extract Inhibits Lipopolysaccharide-Induced Toll-Like Receptor 4 Dimerization

“…[4][5][6][7][8][9] The mechanisms of garlic for its biological activities have been ascribed to its potent antioxidative, 10) antithrombotic 1) and lipid-lowering 11) activities, and to its stimulating ability for immunological responses. 12) Numerous studies have demonstrated that a garlic extract and its related compounds with anti-inflammatory effects inhibited the nuclear factor kappa B (NF-B) activation induced by various receptor agonists, including tumor necrosis factor (TNF) and lipopolysaccharide (LPS), 13,14) and the expression of inducible nitric oxide synthase (iNOS) in activated macrophages. 15,16) NF-B is a central transcription factor for pro-inflammatory gene expression.…”

Beneficial effects of garlic (Allium Sativum) oil inexperimental corrosive esophageal burns

“…[14,22] Studies have indicated that garlic oil shows an anti-inflammatory effect by reducing the production of IL2, IL12, IL6, IL8, and TNF-α and by increasing the production of IL10. [23,24] Keiss et al, [25] showed that garlic oil reduced the activation of NFκB and the production of IL1β and TNF-α. Chang et al, [26] found that garlic oil showed anti-inflammatory effects in suppressing the production of nitric oxide (NO) and prostaglandin E2 in activated macrophages.…”