Catalpol ameliorates LPS-induced endometritis by inhibiting inflammation and TLR4/NF-κB signaling

Abstract

Catalpol is the main active ingredient of an extract from Radix rehmanniae, which in a previous study showed a protective effect against various types of tissue injury. However, a protective effect of catalpol on uterine inflammation has not been reported. In this study, to investigate the protective mechanism of catalpol on lipopolysaccharide (LPS)-induced bovine endometrial epithelial cells (bEECs) and mouse endometritis, in vitro and in vivo inflammation models were established. The Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway and its downstream inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), western blot (WB), and immunofluorescence techniques. The results from ELISA and qRT-PCR showed that catalpol dose-dependently reduced the expression of pro-inflammatory cytokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6, and chemokines such as C-X-C motif chemokine ligand 8 (CXCL8) and CXCL5, both in bEECs and in uterine tissue. From the experimental results of WB, qRT-PCR, and immunofluorescence, the expression of TLR4 and the phosphorylation of NF-κB p65 were markedly inhibited by catalpol compared with the LPS group. The inflammatory damage to the mouse uterus caused by LPS was greatly reduced and was accompanied by a decline in myeloperoxidase (MPO) activity. The results of this study suggest that catalpol can exert an anti-inflammatory impact on LPS-induced bEECs and mouse endometritis by inhibiting inflammation and activation of the TLR4/NF-κB signaling pathway.

Alteration of chemokine production in bovine endometrial epithelial and stromal cells under heat stress conditions

“…Endometrial epithelial and stromal cells were cultured as described in Experiment 1. After LPS treatment for 12 hr (Zhang et al., 2019; Zhu et al., 2015), the medium was collected in a 1.5 ml tube and immediately frozen and stored at − 30°C until the measurement of the concentrations of MCP1, IL‐6, and IL‐8 by ELISA. To normalize the concentration of each chemokine, the cells were harvested and measured the DNA content.…”

Catalpol Inhibits Macrophage Polarization and Prevents Postmenopausal Atherosclerosis Through Regulating Estrogen Receptor Alpha

“…Catalpol, an iridoid glucoside, is extracted from the fresh roots of the traditional Chinese herb Rehmanniae radix preparata. Catalpol shows a wide range of biological activities, like antioxidation, anti-inflammation, anti-cancer, anti-apoptosis, and neuroprotection (Jiang et al, 2015;Yuan et al, 2019;Zhang et al, 2019). Firstly, Liu found that catalpol attenuated atherosclerotic lesions in a rabbit AS model by reducing inflammatory and oxidative stress (Liu and Zhang, 2015).…”

Catalpol ameliorates psoriasis-like phenotypes via SIRT1 mediated suppression of NF-κB and MAPKs signaling pathways

“…Especially, its antioxidant and anti-inflammatory effects were found in a variety of experimental studies in vitro and in vivo [13][14][15][16]. Zhang et al suggested that catalpol alleviated inflammation reactions in LPSstimulated bovine endometrial epithelial cells via the suppression of the TLR4/NF-kB signaling pathway [17]. Catalpol suppressed homocysteineinduced oxidation and inflammation in human aorta endothelial cells [18].…”