2-(3-(chloromethyl)benzoyloxy)benzoic Acid Increases CD4⁺ Regulatory T-Cell Population and FoxP3 Expression in Lipopolysaccharide-induced Mice

BACKGROUND: Lipopolysaccharide (LPS) has been reported to increase CD4⁺ regulatory T-cell (CD4⁺ Treg) populations. Acetylsalicylic acid (ASA) has been reported to have immunomodulatory activity, but it may induce chronic gastric ulceration. Another salicylic acid-bearing compound, 2-(3-(chloromethyl) benzoyloxy)benzoic acid (3-CH₂Cl), has been reported to have less gastric mucosal damage. However, the effect of 3-CH₂Cl on CD4⁺ Tregs in LPS-induced mice is still unknown. Therefore, the present study was conducted to investigate the immunomodulatory effect of 3-CH₂Cl on CD4⁺ T-cell and CD4⁺ Treg populations as well as FoxP3 expression in LPS-induced mice. METHODS: Synthesis of 3-CH₂Cl was performed by mixing salicylic acid and chloromethylbenzoylchloride with the catalyzation of pyridine, acetone and heat. The 3-CH₂Cl tablets were prepared using direct compression method. After intraperitoneal injection of 1 mg/kg BW LPS to mice, 60 mg/kg BW ASA or 60 mg/kg BW 3-CH₂Cl was given orally for 3 days. The splenocyte was obtained through splenectomy and collagenase digestion. The population of CD4⁺ T-cells and CD4⁺ Tregs, as well as the splenic FoxP3 expression were determined using flow cytometry technique. RESULTS: CD4⁺ T-cell populations in mice treated with LPS and 3-CH₂Cl or ASA were lower than those treated with LPS merely. Meanwhile, CD4⁺ Treg populations and FoxP3 expression levels in mice treated with LPS and 3-CH₂Cl or ASA were higher than those treated with LPS merely. CONCLUSION: Since 3-CH₂Cl could decrease CD4⁺ T-cell population and increase CD4⁺ Treg population mediated by the increase of FoxP3 expression in LPSinduced inflammation, it may act as a potential therapeutic drug to reduce inflammatory conditions.