CYP2A13 Acts as the Main Metabolic CYP450s Enzyme for Activating Leonurine in Human Bronchial Epithelial Cells.

BACKGROUND Leonurine is an active component of the traditional Chinese medicine Leonurus japonicus. This study aimed to investigate the effects of overexpressed CYP450s on the metabolic activity of leonurine. MATERIAL AND METHODS BEAS-2B cells stably expressing CYP1A1, 1A2, 2A13, 2B6, and 3A4 were constructed. CYP450s expression was identified using reverse-transcription PCR and Western blot assay. CCK-8 assay was used to evaluate the effect of leonurine on cell activity. Leonurine was incubated in vitro with CYP1A1, 1A2, 2A13, 2B6, and 3A4 metabolic enzymes to evaluate the clearance rate of CYP450 enzymes for leonurine. UPLC-MS was used to detect changes of drug concentration and discover the main metabolic enzymes affecting leonurine. RESULTS BEAS-2B cells stably expressing CYP1A1, 1A2, 2A13, 2B6, and 3A4 were successfully constructed. According to primary mass spectra and secondary mass spectra of leonurine, the main metabolic enzymes were 312.1550 [H+] and 181.0484. Compared to the control group, residue of leonurine in CYP2A13 group was significantly reduced (F=5.307, p=0.024). Compared to the 0-min group, the clearance rate of leonurine in the CYP2A13-treated group was significantly decreased at 120 min after treatment (F=7.273, p=0.007). CCK-8 results also showed that activity of BEAS-2B cells that overexpress CYP2A13 gradually decreased with increased concentration of leonurine. Although CYP2A13 demonstrated good metabolic activity for leonurine, we found that CYP1A1, 1A2, 2B6, and 3A4 had no metabolic effects on leonurine. CONCLUSIONS Leonurine can be effectively activated through CYP2A13 enzyme metabolism, and further inhibits activity of human lung epithelial cells (BEAS-2B). Therefore, CYP2A13 is a main metabolic enzyme for leonurine in BEAS-2B cells.

Curcumin improves LPS-induced preeclampsia-like phenotype in rat by inhibiting the TLR4 signaling pathway.

INTRODUCTION: Abnormal inflammation mediated by Toll-like receptor 4 (TLR4) signaling pathway contributes to preeclampsia (PE). Because curcumin can inhibit TLR4 signaling pathway, we investigated its effects on a PE rat model. METHODS: Twenty-one pregnant rats were randomly divided into three groups: 1) seven rats were injected 0.5 µg/kg lipopolysaccharide (LPS) on gestational day (GD) 5 to create a PE model (LPS-treated group), 2) seven rats were injected with a similar dosage of LPS and further treated with curcumin (0.36 mg/kg) (LPS-curcumin-treated group), 3) seven rats received saline (control group). Blood pressure and urinary protein level were observed. Immunostaining and periodic acid-Schiff staining of placenta were conducted. TLR4 and downstream Nuclear Factor-κB (NF-κB) expressions of placenta were analyzed by Western blot and immunohistochemistry. IL-6 and MCP-1 in rat serum and placenta were determined by ELISA and qRT-PCR. RESULTS: Compared to LPS-treated group, LPS-curcumin-treated group had decreased blood pressure and urinary protein level, similar to control group. Furthermore, deficient trophoblast invasion and spiral artery remodeling induced by LPS were improved by curcumin. Increased TLR4, NF-κB and IL-6, MCP-1 protein expressions in LPS-treated group were significantly decreased after curcumin administration. DISCUSSION: Curcumin improves the PE-like phenotype in rat model by reducing abnormal inflammation related to TLR4 signaling pathway.