Effects of β-lapachone on the production of Th1 and Th2 cytokines in C57BL/6 mice.

In this study, we investigated the effects of β-lapachone (β-lap) on the production of cytokines in C57BL/6 mice. The culture supernatants of splenocytes exposed to β-lap plus lipopolysaccharide or concanavalin A (Con A) were harvested to determine Th1 (tumor necrosis factor-α, interferon-γ, interleukin [IL]-1β, IL-2, IL-17A, and IL-12) and Th2 (IL-4, IL-5, IL-6, and IL-10) cytokines. IL-2, a Th1 cytokine, was expressed at higher levels in splenocytes treated with β-lap and with lipopolysaccharide plus β-lap. Expression of Th2 cytokines, including IL-4, IL-5, IL-6, and IL-10, was lower in the culture supernatants of mouse splenocytes exposed to Con A plus β-lap than in supernatants from cells that were exposed to Con A alone. These findings demonstrate that β-lap downregulates the immediate hypersensitivity reaction induced by Con A. Therefore, Th2 responses involve the downregulation of IL-4, IL-5, IL-6, and IL-10, preventing the occurrence of allergies and various manifestations of allergic inflammation. These results suggest that β-lap may have potential preventive or adjunct anti-inflammatory therapy applications because of its function in modulating the production of cytokines. However, further in vivo investigations of this process are necessary to elucidate the mechanisms involved.