Allium sativum L. regulates in vitro IL-17 gene expression in human peripheral blood mononuclear cells

Abstract

BackgroundAllium sativum L. (A.S.) “garlic”, one of the most interesting medicinal plants, has been suggested to contain compounds that could be beneficial in numerous pathological situations including cancer. In this work, we aimed to assess the immunomodulatory effect of A.S. preparation on human peripheral blood mononuclear cells from healthy individuals.MethodsNontoxic doses of A.S. were identified using MTT assay. Effects on CD4+ or CD8+ T lymphocyte proliferation were studied using flow cytometry. The effect of A.S. on cytokine gene expression was studied using qRT-PCR. Finally, qualitative analysis of A.S. was performed by HPLC approach. Data were analyzed statistically by one-way ANOVA test.ResultsThe nontoxic doses of A.S. preparation did not affect neither spontaneous nor TCR-mediated CD4+ or CD8+ T lymphocyte proliferation. Interestingly, A.S. exhibited a statistically significant regulation of IL-17 gene expression, a cytokine involved in several inflammatory and autoimmune diseases. In contrast, the expression of IL-4, an anti-inflammatory cytokine, was unaffected. Qualitative analysis of A.S. ethanol preparation indicated the presence of three polyphenol bioactive compounds, which are catechin, vanillic acid and ferulic acid.ConclusionThe specific inhibition of the pro-inflammatory cytokine, IL-17 without affecting cell proliferation in human PBMCs by the Allium sativum L. preparation suggests a potential valuable effect of the compounds present in this plant for the treatment of inflammatory diseases and cancer, where IL-17 is highly expressed. The individual contribution of these three compounds to this global effect will be assessed.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-016-1365-9) contains supplementary material, which is available to authorized users.

In Vitro and In Vivo Immunomodulator Activities of Allium sativum L.

“…Keiss et al have shown that garlic powder extracts modulated lipopolysaccharide-induced cytokine levels in human whole blood, such as reducing proinflammatory cytokine like IL-1 β and TNF- α , whereas the expression of the anti-inflammatory cytokine IL-10 was unchanged [ 54 ]. These data are consistent with ours, where we showed that human Peripheral Blood Mononuclear Cells (PBMCs) treated with garlic extract did not affect IL-4 expression while inhibiting significantly the proinflammatory cytokine IL-17 [ 44 ]. These immunomodulatory properties of garlic could be useful in clinical applications, since it enhances innate and specific cell immunity and also improves host resistance.…”

“…In the same direction, γδ T cell population, the only type of T cell that recognizes and responds to pathogen-associated molecular patterns (PAMP), increased its proliferation after aged garlic extract supplementation in healthy humans [ 43 ]. However, data from our group showed that garlic extract did not seem to have any effect neither on spontaneous nor PHA-induced proliferation of human CD4+ and CD8+ T lymphocytes [ 44 ]. As for other garlic compounds, like sulfur-containing components, these also showed a modulatory effect on T cell proliferation.…”

The effects of garlic (Allium sativum) supplementation on inflammatory biomarkers, fatigue, and clinical symptoms in patients with active rheumatoid arthritis: A randomized, double‐blind, placebo‐controlled trial

“…Therefore, comparing the results of this study and discussing the effects are difficult. response and inhibit the IL-17 gene expression in Thp17 cells (Moutia et al, 2016;Zamani, Vahidinia, & Ghannad, 2009).…”

“…Therefore, inhibition of these cytokines results in reduced production of inflammatory factors such as CRP. In addition, garlic compounds balance the Thp1/Thp2 response and inhibit the IL‐17 gene expression in Thp17 cells (Moutia et al, 2016; Zamani, Vahidinia, & Ghannad, 2009).…”

Immunomodulatory Effects of Glutathione, Garlic Derivatives, and Hydrogen Sulfide

“…Different types of garlic supplements are commercially available, and the profile of sulfur-containing compounds varies according to manufacturing processes. Several in vivo and in vitro studies have demonstrated the beneficial effects of garlic consumption, such as antioxidant [ 44 , 45 , 46 ], cardioprotective [ 47 ], anti-inflammatory [ 46 , 48 ] and anti-microbial [ 49 ], and these effects are mediated through different mechanisms, depending on the sulfur-containing compound profiling. Among the different supplements, aged garlic extract (AGE) accounts for the most studied product associated with health benefits.…”