Orostachys japonicus Inhibits Expression of the TLR4, NOD2, iNOS, and COX-2 Genes in LPS-Stimulated Human PMA-Differentiated THP-1 Cells by Inhibiting NF-κB and MAPK Activation.

Orostachys japonicus is traditionally used as an inflammatory agent. In this report, we investigated the effects of O. japonicus extract on the expression of genes encoding pathogen-recognition receptors (TLR2, TLR4, NOD1, and NOD2) and proinflammatory factors (iNOS, COX-2, and cytokines) in LPS-stimulated PMA-differentiated THP-1 cells and the NF-κB and MAPK pathways. O. japonicus induced toxicity at high concentrations but had no effect at concentrations lower than 25 µg/mL. O. japonicus inhibited LPS-induced TLR4 and NOD2 mRNA levels, suppressed LPS-induced iNOS and COX-2 transcription and translocation, and downregulated LPS-induced proinflammatory cytokine (IL-1ß, IL-6, IL-8, and TNF-α) mRNA levels. In addition, O. japonicus inhibited LPS-induced NF-κB activation and IκBα degradation and suppressed LPS-induced JNK, p38 MAPK, and ERK phosphorylation. Overall, our results demonstrate that the anti-inflammatory effects of O. japonicus are mediated by suppression of NF-κB and MAPK signaling, resulting in reduced TLR4, NOD2, iNOS, and COX-2 expression and inhibition of inflammatory cytokine expression.

Orostachys japonicus inhibits the expression of MMP-2 and MMP-9 mRNA and modulates the expression of iNOS and COX-2 genes in human PMA-differentiated THP-1 cells via inhibition of NF-κB and MAPK activation.

Orostachys japonicus has been used in traditional medicine as an anticancer agent. The present study aimed to investigate the mechanism by which O. japonicus extract affects the expression of matrix metalloproteinase (MMP)-2 and MMP-9, its association with the expression of the inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) genes in phorbol myristate acetate-differentiated THP-1 human monocytic leukemia cells and how it mediates the nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) pathways. Cell proliferation was analyzed by MTT assay, mRNA expression was detected by quantitative polymerase chain reaction and protein expression was measured by western blot analysis. It was demonstrated that O. japonicus suppressed the mRNA expression of MMP-2 and MMP-9. In addition, O. japonicus was found to downregulate iNOS and COX-2 transcription and translocation. Furthermore, O. japonicus inhibited NF-κB p65 activity as well as the phosphorylation of p38 MAPK, MAPK kinase (MEK) and extracellular signal regulated kinase (ERK). The present results suggested that O. japonicus inhibited not only MMP-2 and MMP-9 mRNA expression, but also iNOS and COX-2 gene expression, suppressed NF-κB activation and reduced phosphorylation of p38 MAPK, MEK and ERK. The present results therefore indicated that O. japonicus was able to inhibit the expression of MMP-2 and MMP-9 and suppress the transcription and translocation of iNOS and COX-2 by directly inhibiting the activation of NF-κB and the phosphorylation of the MAPK pathway in THP-1 cells.

Chelidonium majus L. extract induces apoptosis through caspase activity via MAPK-independent NF-κB signaling in human epidermoid carcinoma A431 cells.

Chelidonium majus L. (C. majus L.) is known to possess certain biological properties such as anti-inflammatory, antimicrobial, antiviral and antitumor activities. We investigated the effects of C. majus L. extract on human epidermoid carcinoma A431 cells through multiple mechanisms, including induction of cell cycle arrest, activation of the caspase-dependent pathway, blocking of nuclear factor-κB (NF-κB) activation and involvement in the mitogen-activated protein kinase (MAPK) pathway. C. majus L. inhibited the proliferation of A431 cells in a dose- and time-dependent manner, increased the percentage of apoptotic cells, significantly decreased the mRNA levels of cyclin D1, Bcl-2, Mcl-1 and survivin and increased p21 and Bax expression. Exposure of A431 cells to C. majus L. extract enhanced the activities of caspase-3 and caspase-9, while co-treatment with C. majus L., the pan-caspase inhibitor Z-VAD-FMK and the caspase-3 inhibitor Z-DEVE-FMK increased the proliferation of A431 cells. C. majus L. extract not only inhibited NF-κB activation, but it also activated p38 MAPK and MEK/ERK signaling. Taken together, these results demonstrate that C. majus L. extract inhibits the proliferation of human epidermoid carcinoma A431 cells by inducing apoptosis through caspase activation and NF-κB inhibition via MAPK-independent pathway.