Schizonepeta tenuifolia inhibits the development of atopic dermatitis in mice.

Historically, Schizonepeta tenuifolia (ST) has been used for the treatment of skin disorders, such as allergic dermatitis, eczema, and inflammatory diseases. In this study, we examined whether ST inhibited 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD) in BALB/c mice. In histopathological analyses of the epidermis and dermis, skin thickness was significantly increased in DNCB-induced mice as compared with normal group. Treatment with ST inhibited this inflammatory change and markedly suppressed the secretion of immunoglobulin E, tumor necrosis factor α, and interleukin 6 levels in the serum of DNCB-induced mice. In addition, ST treatment significantly restored the upregulation of proinflammatory factors, such as nuclear factor (NF)-κB and mitogen-activated protein kinase expression. Taken together, due to its ability to suppress inflammatory factors and upregulate proinflammatory factors, ST may be useful as a therapeutic treatment for AD. ST extract application decreased both epidermis and dermis thickness in DNCB-induced mice. In serum, ST reduced immunoglobulin E, tumor necrosis factor, and interleukin 6 level. In addition, ST suppressed NF-κB activation as well as the mitogen-activated protein kinase activities.

Xanthii fructus inhibits inflammatory responses in LPS-stimulated RAW 264.7 macrophages through suppressing NF-κB and JNK/p38 MAPK.

ETHNOPHARMACOLOGICAL RELEVANCE: Xanthii fructus (XF) has long been used to treat a variety of inflammatory conditions in Korean traditional medicine, but the underlying mechanisms that could explain the anti-inflammatory actions of XF remain largely unknown. AIM OF THE STUDY: This study aimed to elucidate the anti-inflammatory effects of X. fructus (XF) and to examine its underlying molecular mechanisms in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. MATERIALS AND METHODS: The effect of XF on LPS-induced mRNA and protein expressions of inflammatory mediators and cytokines were determined. Moreover, the activation of the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways and the expression of heme oxygenase-1 (HO-1) were explored to elucidate the anti-inflammatory mechanisms. RESULTS: XF significantly inhibited LPS-induced production of inflammatory mediators, interleukin-6 (IL-6), nitric oxide (NO), and prostaglandin E2 (PGE2), without any cytotoxicity. However, it did not affect tissue necrosis factor (TNF)-α or IL-1ß production in LPS-stimulated RAW 264.7 cells. Expression levels of inducible nitric oxide synthase (iNOS) mRNA and protein were inhibited dose-dependently by XF in LPS-stimulated RAW 264.7 cells, but there were no changes in cyclooxygenase-2 (COX-2) mRNA and protein. XF significantly attenuated LPS-induced phosphorylation and degradation of inhibitory kappa Bα (IκBα) and consequently reduced the nuclear translocation of p65 NF-κB. Pretreatment with XF also strongly inhibited the LPS-induced phosphorylation of p38 kinase and JNK, whereas the phosphorylation of ERK1/2 was not affected. In addition, XF led to an increase in HO-1 expression. CONCLUSION: Taken together, our findings support that XF inhibits LPS-induced inflammatory responses by blocking NF-κB activation, inhibiting JNK/p38 MAPK phosphorylation, and enhancing HO-1 expression in macrophages, suggesting that it could be an attractive therapeutic candidate for various inflammatory diseases.