Oxyimperatorin attenuates LPS-induced microglial activation in vitro and in vivo via suppressing NF-κB p65 signaling.

BACKGROUND: Microglia-mediated neuroinflammation is an important pathological feature in many neurological diseases; thus, suppressing microglial activation is considered a possible therapeutic strategy for reducing neuronal damage. Oxyimperatorin (OIMP) is a member of furanocoumarin, isolated from the medicinal herb Glehnia littoralis. However, it is unknown whether OIMP can suppress the neuroinflammation. PURPOSE: To investigate the neuroprotective activity of oxyimperatorin (OIMP) in LPS-induced neuroinflammation in vitro and in vivo models. METHODS: In vitro inflammation-related assays were performed with OIMP in LPS-induced BV-2 microglia. In addition, intraperitoneal injection of LPS-induced microglial activation in the mouse brain was used to validate the anti-neuroinflammatory activity of OIMP. RESULTS: OIMP was found to suppress LPS-induced neuroinflammation in vitro and in vivo. OIMP significantly attenuated LPS-induced the production of free radicals, inducible nitric oxide synthase, cyclooxygenase-2, and pro-inflammatory cytokines in BV-2 microglia without causing cytotoxicity. In addition, OIMP could reduce the M1 pro-inflammatory transition in LPS-stimulated BV-2 microglia. The mechanistic study revealed that OIMP inhibited LPS-induced NF-κB p65 phosphorylation and nuclear translocation. However, OIMP did not affect LPS-induced IκB phosphorylation and degradation. In addition, OIMP also was able to reduce LPS-induced microglial activation in mice brain. CONCLUSION: Our findings suggest that OIMP suppresses microglia activation and attenuates the production of pro-inflammatory mediators and cytokines via inhibition of NF-κB p65 signaling.

Huangjia Ruangan Granule Inhibits Inflammation in a Rat Model with Liver Fibrosis by Regulating TNF/MAPK and NF-κB Signaling Pathways.

The Huangjia Ruangan granule (HJRG) is a clinically effective Kampo formula, which has a significant effect on liver fibrosis and early liver cirrhosis. However, the mechanism underlying HJRG in treating liver fibrosis remains unclear. In this study, carbon tetrachloride (CCl4) was used to induce liver fibrosis in rats to clarify the effect of HJRG on liver fibrosis and its mechanism. Using network pharmacology, the potential mechanism of HJRG was initially explored, and a variety of analyses were performed to verify this mechanism. In the liver fibrosis model, treatment with HJRG can maintain the liver morphology, lower the levels of AST and ALT in the serum, and ameliorate pathological damage. Histopathological examinations revealed that the liver structure was significantly improved and fibrotic changes were alleviated. It can effectively inhibit collagen deposition and the expression of α-SMA, reduce the levels of the rat serum (HA, LN, PC III, and Col IV), and inhibit the expression of desmin, vimentin, and HYP content in the liver. Analyzing the results of network pharmacology, the oxidative stress, inflammation, and the related pathways (primarily the TNF signaling pathway) were identified as the potential mechanism of HJRG against liver fibrosis. Experiments confirmed that HJRG can significantly increase the content of superoxide dismutase and glutathione and reduce the levels of malondialdehyde and myeloperoxidase in the rat liver; in addition, HJRG significantly inhibited the content of proinflammatory cytokines (TNF-α, IL-1ß, and IL-6) and reduced the expression of inflammatory regulators (Cox2 and iNOS). Meanwhile, treatment with HJRG inhibited the phosphorylation of NF-κB P65, IκBα, ERK, JNK, and MAPK P38. Moreover, HJRG treatment reversed the increased expression of TNFR1. The Huangjia Ruangan granule can effectively inhibit liver fibrosis through antioxidation, suppressing liver inflammation by regulating the TNF/MAPK and NF-κB signaling pathways, thereby preventing the effect of liver fibrosis.

SiNiSan ameliorates depression-like behavior in rats by enhancing synaptic plasticity via the CaSR-PKC-ERK signaling pathway.

BACKGROUND: Adverse stress in early life negatively influences psychiatric health by increasing the risk of developing depression and suicide in adulthood. Clinical antidepressants, such as fluoxetine, exhibit unsatisfactory results due to their low efficacy or intolerable side effects. SiNiSan (SNS), a traditional Chinese herbal formula, has been proven to have affirmatory antidepressive effects. However, the underlying mechanism remains poorly understood. Therefore, this study aimed to explore the impact and molecular mechanism of SNS treatment in rats exposed to neonatal maternal separation (MS)-combined young-adult chronic unpredictable mild stress (CUMS). METHOD: Seventy-two neonatal male Sprague-Dawley rats were randomly divided into six groups of 12 rats each: control + ddH2O, model + ddH2O, positive (fluoxetine: 5 mg/kg), SNS-low dose (2.5 g/kg), SNS-medium dose (5 g/kg), and SNS-high dose (10 g/kg). Behavioral tests included sucrose preference test, open-field test, and forced swimming test. Calcium sensitive receptor (CaSR), protein kinase C (PKC), ERK1/2, and synapse-associated proteins (PSD-95, GAP-43, and synaptophysin [Syn]) in the hippocampus (HIP) and prefrontal cortex (PFC) were assayed using Western blot. CaSR and Syn protein expression was measured by immunohistochemistry. RESULTS: MS-combined CUMS rats exhibited depression-like behavior. SNS exerted antidepressant effects on stress-induced depression-like behavior. The levels of CaSR, PKC, and p-ERK1/2 in the HIP and PFC decreased in stressed rats. SNS treatment significantly upregulated the expression of CaSR, PKC, and p-ERK1/2 in the HIP and PFC of adult stressed rats. CONCLUSION: MS-combined CUMS could develop depression-like behavior in adult. SNS exhibited antidepressive effects accompanied by improving synaptic plasticity by activation of the CaSR-PKC-ERK signaling pathway.