Search

Inhibition of endoplasmic reticulum (ER) stress reduces blood-brain barrier (BBB) injury caused by ischemia/reperfusion (I/R), with indistinct mechanisms. Salvinorin A (SA) relieves I/R-induced BBB leakage; however, whether it is related to the suppression of ER stress is yet unclear. To address this question, we have used both a rat model of middle cerebral artery occlusion (MCAO) and human brain microvascular endothelial cells (HBMECs) with oxygen-glucose deprivation (OGD). SA was injected by tail vein at the terminal of ischemia; Norbinaltorphimine (NB), a kappa opioid antagonist, was administered 30 min prior to SA; 4-phenylbutyric acid (4-PBA), an ER stress inhibitor, was injected intraperitoneally after the onset of ischemia; adenylate-activated protein kinase (AMPK)-specific small interfering RNAs (siRNAs) were transfected to HBMECs before OGD. The assessment was as follows: infarct volume, brain water gain, Evans blue leakage, and modified neurological severity score (mNSS) after MCAO; HBMECs apoptosis rate and permeability, ER stress-related protein, and reactive oxygen species (ROS) and calcium levels after OGD. The results showed that SA significantly reduced the BBB leakage in vivo; SA relieved the apoptotic rates and ER stress in HBMECs, protected the permeability of HBMECs, and reduced ROS and calcium ion level after OGD. Moreover, the SA function was blocked by NB in vivo and AMPK- siRNAs in vitro. We conclude that SA mitigated BBB damage and HBMEC injury after I/R and alleviated ER stress in endothelial cells via AMPK pathway. • Salvinorin A is a highly selective kappa-opioid receptor agonist. • Salvinorin A confers neuroprotection in cerebral ischemia-reperfusion injury. • Salvinorin A mitigated blood-brain damage and endothelial cells injury after ischemia/reperfusion. • Salvinorin A relieved the endothelial cell injury via AMPK pathway. [ABSTRACT FROM AUTHOR]

Clinical poisoning events involving yunaconitine (YAC), a toxic Aconitum alkaloid, occur more and more frequently, and whether the mechanism is correlated with metabolism-based interactions remains unknown. This study aimed to reveal the presumable mechanism by clarifying the metabolic profiles and kinetic-based mechanism of YAC. YAC could be oxidized into 20 metabolites by human liver microsomes, while CYP3A4 have a critical metabolic superiority. Sixteen of the metabolites were primary generated by CYP3A4, and 4 of them were generated only by CYP3A4. The presence of CYP3A inhibitor ketoconazole (KCZ) significantly suppressed the generation of all the 20 metabolites, with 9 of them being suppressed completely (P < 0.05). The plasma exposure (C max and AUC 0-t values), cardiotoxicity and neurotoxicity of YAC enhanced remarkably in mice when Cyp3a were inhibited (P < 0.05). Moreover, the CYP3A4-based kinetics of YAC is an example of substrate inhibition, and the inhibitory manner of YAC on CYP3A4 was competitive, with K i value being 1.76 μmol/L. Overall, YAC was a sensitive substrate and moderately competitive inhibitor of CYP3A4. The inhibition on CYP3A4 could sharply increase the in vivo exposure and toxicity of YAC. Thus, clinical poisoning events involving YAC may be highly correlated with CYP3A4-mediated interactions. [Display omitted] • YAC is critically metabolized by CYP3A4. • YAC is a sensitive substrate of CYP3A4. • Enzymatic kinetic profile of YAC is substrate inhibition. • The inhibitory manner of YAC on CYP3A4 is competitive. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Selaginella doederleinii Hieron has been used as a folk medicine for the treatment of different cancers, especially for nasopharyngeal carcinoma, lung cancer and trophoblastic tumor in China. Previously, the ethyl acetate extract from S. doederleinii (SDEA extract) showed favorable anti-cancer potentials. However, the main chemical composition and anticancer mechanism of the SDEA extract were still not very clear. Until now, there are no reports available about the oral toxicity of the extract. Aim of study The present study was to further elucidate the chemical composition and anti-lung cancer mechanism of the SDEA extract, and evaluate the acute oral toxicity of the extract. Materials and methods The SDEA extract was separated and analysed by HPLC to disclose its main chemicals. The effects of the extract were then investigated in vitro on cell viability, apoptosis and cell cycle using fluorescence microscopy and flow cytometry, and the molecular mechanism against human lung cancer cells A549 was further studied by western blot assays. The in vivo anti-cancer effect of the extract was evaluated in A549 xenograft mice model by histochemical assay, and tumor growth, microvascular density (MVD) and Ki67 expression were also measured. In addition, acute oral toxicity test of the extract was executed in mice. Results SDEA extract mainly contained eight biflavonoids. The extract caused the loss of mitochondrial membrane potential and induced cell apoptosis by upregulating Bax, downregulating Bcl-2, activating caspase-9 and caspase-3 and blocked the cell cycle in S phase. The extract reduced expression of antigen Ki67, decreased MVD, and significantly inhibited the tumor growth. The extract did not show apparent oral acute toxicity in healthy mice. Conclusion The SDEA extract exerted anti-tumor effect through activating mitochondrial pathways and reducing Ki67 expression and MVD. Low oral acute toxicity suggested it a promising chemotherapy agent. [ABSTRACT FROM AUTHOR]

Highlights: [•] BCRP was involved in the efflux of rhein. [•] MRP2 did not participate in the efflux of rhein. [•] P-gp did not affect the rhein transport. [ABSTRACT FROM AUTHOR]

Highlights: [•] Human epidermal melanocytes were isolated, cultured and purified. [•] The practicability of supporting materials of cultured melanocytes was investigated. [•] Polyethylene terephthalate film was proved to be an ideal supporting material for melanocyte culture. [•] The application of polyethylene terephthalate film enables melanocytes and their dendrites to be sectioned longitudinally. [•] Ultrastructures of melanocytes and transferring pattern of melanosomes were observed. [ABSTRACT FROM AUTHOR]

Abstract: Nicotinamide (NAM), the amide form of vitamin B3, is involved in a wide range of biological processes. Recent evidence revealed the anti-inflammatory and anti-oxidant properties of NAM and suggests it may be used as a novel strategy in the prevention of acute liver injury. In the present study, we investigated the potential protective effects of NAM on acetaminophen (APAP)-induced acute liver injury in mice. Mice were treated with NAM at 400mg/kg 30min before or after administration of APAP at a hepatotoxic dose of 400mg/kg body weight via intraperitoneal injection. Liver injury and the expression of inflammation-related molecules were determined by histological examination and biochemical analysis, respectively. In addition, the survival rate of mice was assessed after APAP administration. Pretreatment with NAM for 30min significantly decreased plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA), and diminished histopathologic evidence of hepatic toxicity in mice following APAP administration. Similarly, posttreatment with NAM also decreased plasma ALT and AST levels in APAP-administrated mice. Furthermore, both pretreatment and posttreatment with NAM prolonged the survival rate of acute liver injury mice, accompanied by a significant reduction in the plasma levels of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), and interleukin-6 (IL-6). Together, these findings suggest that NAM possesses protective effects on APAP-induced liver injury, which may involve the anti-inflammatory action. [Copyright &y& Elsevier]