6'-O-galloylpaeoniflorin alleviates inflammation and oxidative stress in pediatric pneumonia through activating Nrf2 activation

Objective: To assess the therapeutic effect and mechanism of 6'-o-galloylpaeoniflorin (GPF) in pediatric pneumonia.Methods: The effects of lipopolysaccharide (LPS) and GPF on cell viability and apoptosis were examined by cell counting kit-8 assay and flow cytometry analysis. The oxidative stress and inflammatory response were assessed by detecting expression levels of superoxide dismutase, glutathione, r-glutamyl cysteingl+glycine, myeloperoxidase, and malondialdehyde as well as tumor necrosis factor-α, Interleukin-18, and Interleukin-10 by using enzyme-linked-immuno-sorbent serologic assay. Moreover, the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway was detected by immunoblot assay, and the influence of Nrf2-knockdown on cell viability, oxidative stress, and inflammation response was also investigated.Results: The results established that GPF increased the viability of LPS-induced pneumonia cells. In addition, GPF reduced LPS-induced oxidative stress in pneumonia cells. It was further discovered that GPF reduced LPS-induced inflammation in pneumonic cell. GPF improved the activity of Nrf2 in LPS-treated pneumonic cells, and therefore alleviated inflammation and oxidative stress in pediatric pneumonia.Conclusion: GPF could serve as a promising drug for treating pediatric pneumonia (AU)

Transcriptional regulation of the NAD(P)H:quinone oxidoreductase 1 and glutathione S-transferase ya genes by mercury, lead, and copper.

Recently, we demonstrated the ability of heavy metals, particularly Hg2+, Pb2+, and Cu2+, to differentially modulate in Hepa 1c1c7 cells the expression of the phase II xenobiotic metabolizing enzymes NAD(P)H:quinone oxidoreductase 1 (Nqo1) and glutathione S-transferase subunit Ya (Gst ya) genes, yet the mechanisms involved remain unknown. To investigate the molecular mechanisms involved in the regulation of Nqo1 and Gst ya genes by heavy metals, Hepa 1c1c7 cells were treated with Hg2+, Pb2+, or Cu2+ in the presence and absence of 2,3,7,8-tetrachlorodibenzo-p-dioxin, a potent inducer of Nqo1, Gst ya, and Cyp1a1 genes. Analysis of the time-dependent effect of heavy metals revealed that Hg2+ and Pb2+ increased whereas Cu2+ inhibited the constitutive and inducible expression of Nqo1 and Gst ya mRNAs in a time-dependent manner. The RNA synthesis inhibitor actinomycin D significantly inhibited the Nqo1 and Gst ya mRNA induction in response to metals, indicating a requirement of de novo RNA synthesis. The protein synthesis inhibitor cycloheximide significantly inhibited metal-mediated induction of Nqo1 and Gst ya mRNAs, which coincided with a decrease in the nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression, implying the requirement of Nrf2 protein synthesis for the induction of these genes. Furthermore, inhibition of Nrf2 protein degradation by carbobenzoxy-L-leucyl-L-leucyl-leucinal (MG-132), a 26S proteasome inhibitor, significantly reversed the cycloheximide-mediated inhibition of Nqo1 and Gst ya mRNAs, which coincided with an increase in the expression of Nrf2, confirming that a transcriptional mechanism is involved. Nqo1 and Gst ya mRNA and protein decay experiments revealed lack of post-transcriptional and post-translational mechanisms. This is the first demonstration that heavy metals regulate the expression of Nqo1 and Gst ya genes through a transcriptional mechanism.