Resveratrol Attenuates the Cytotoxicity Induced by Amyloid-ß1-42 in PC12 Cells by Upregulating Heme Oxygenase-1 via the PI3K/Akt/Nrf2 Pathway.

Oxidative stress and cytotoxic damage induced by amyloid beta (Aß) have been considered pivotal in the pathogenesis of Alzheimer's disease (AD) and may represent a target for treatment. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway elicits a survival signal to protect against multiple injuries, and the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), a downstream target of the PI3K/Akt pathway, can bind to HO-1. Resveratrol, a natural polyphenol derived from grapes, has been widely reported to have diverse antioxidative effects against AD, but the mechanisms have not been fully elucidated. The present study aims to investigate the effects of resveratrol on Aß1-42-induced cytotoxicity in PC12 cells and to explore the potential mechanisms of these effects. PC12 cells were cultured and treated with Aß1-42. Oxidative stress was assessed by measuring malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) levels. After treating with resveratrol at different concentrations (0, 10, 20, 40 µM) and for different durations (24, 48, 72 h), the generation of MDA, GSH, and SOD were detected; cell viability was assessed by MTT assay. The production of reactive oxygen species (ROS) was determined using an ROS Assay Kit. Western blotting was used to detect the protein expression. Our studies showed that pretreatment with resveratrol could reduce Aß1-42-induced oxidative stress in PC12 cells by inhibiting the generation of MDA and ROS and increasing the production of SOD and GSH. Resveratrol markedly attenuated the Aß1-42-induced loss in cell viability in PC12 cells in both a dose- and time-dependent manner. More importantly, resveratrol stimulated the activation of HO-1, Nrf2, PI3K, and phosphorylated Akt. Notably, the neuroprotective effects of resveratrol were eliminated by the HO-1 inhibitor zinc protoporphyrin IX (ZnPP), Nrf2 small interfering RNA (siRNA), and the PI3K/Akt inhibitor LY294002. Taken together, the findings suggest that the cytoprotection of resveratrol against the cytotoxicity induced by Aß1-42 in PC12 cells is through the upregulation of HO-1 expression via the activation of the PI3K/AKT/Nrf2 intracellular signaling pathway, which might provide novel insights for understanding the mechanism of the neuroprotective effect of resveratrol as an anti-AD drug.

IL-37 protects hepatocyte injury against hypoxia/reoxygenation by promoting polarization of M2-type macrophages / 复旦学报（医学版）

Objective To investigate the protective effect of IL-37 on hepatocyte injury against hypoxia/reoxygenation (H/R) by promoting polarization of M2-type macrophages and its molecular mechanisms.Methods Real-time fluorescent quantitative PCR (qRT-PCR) and Western blot were used to detect the levels of IL-37 mRNA and protein in human monocyte-macrophage THP-1 cells with different polarizations.The lentivirus with IL-37 gene was infected into THP-1 cells.The levels of CD206,CD86,ARG1 and iNOS mRNA was detected by qRT-PCR.The levels of CD163 and CD86 protein was detected by flow cytometric analysis.THP-1 cells and L02 cells were co-cultured by Transwell and treated with H/R.The survival rate and apoptotic rate of L02 cells were detected.The levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) in culture medium were measured.The levels of STAT6 and its phosphorylation in THP-1 cells were detected by Western blot.Results The levels of IL-37 mRNA and protein were up-regulated in M2-type macrophages.IL-37 promoted the polarization of M2-type macropahges.M2-type macrophages induced by IL-37 were cocultured with L02 cells,the survival rate was significantly increased by H/R treatment (P =0.015),while the apoptotic rate,ALT level and AST level were significantly decreased (P＜0.001).The level of phosphorylated STAT6 in THP-1 cells overexpressing IL-37 was up-regulated (P ＜ 0.01).Conclusions IL-37 can induce polarization of M2-type macrophages and protect hepatocyte injury against H/R.Its mechanism may be related to STAT6 signal pathways.

Treatment of experimental allergic conjunctivitis with musk eye drops in guinea pigs / 中成药

AIM: To investigate the therapeutic effect and its mechanisms of musk eye drops on allergic conjunctivitis (AC) in guinea pigs.METHODS: AC was developed by intraperitoneal injection of a mixture containing Ovalbumin (OVA) and Al(OH)3 in guinea pig.Sixty guinea pigs with AC were randomly divided into 6 groups,i.e.,AC model group,three treated groups treated with musk eye drops in high,middle and low dosage,group treated with dexamethasone sodium phosphate eye drops.Together with solvent group as sixth group.After one week of administration,the changes of guinea pigs in symptoms,histamine and OVA-specific IgE concentration of ocular tissues,and morphological features of conjunctiva were observed under light microscopy.RESULTS: Compared with the vehicle group,the conjunctiva symptoms scale,histamine and OVA-specific IgE concentration of ocular tissues and morphological changes scale of conjunctiva of guinea pigs in the model group were fairly good.Compared with the model group,the ocular symptoms of guinea pigs in each of the musk eye drops treated groups showed relieved (P

Intra-ocular distribution and pharmacokinetics of musk eye drops in the rabbits / 中成药

AIM: To study intra-ocular distribution and pharmacokinetics of musk eye drops in the rabbit eyes.METHODS: After administration,twenty seven rabbits were euthanatized and taken eye in 0.083 h,0.167 h,0.5 h,1 h,2.0 h,4.0 h,8.0 h and 12 h,and then isolated aqueous humor,vitreous body,further cornea and ciliary margin of iris from rabbits’eyes.The intraocular concentrations of muscone were measured by GC after topical instillation with 10% musk solution in rabbits.The pharmacokinetic parameters were calculated with 3p97 program.RESULTS: Results showed that the peak concentrations(max) of muscone in various ocular tissues were (107.52 ?67.07),(2.15 ?1.49),(0.034 ?0.007 6),(2.87 ?1.50) and(0.013 ?0.004 5)?g/g or ?g/mLin lacrimal fluid,cornea,aqueous humor,iris and vitreous body;Its half-Life(T1/2) was(8.08 ? 3.08),(2.87? 2.24),(3.37 ? 0.68),(4.69 ? 1.32) and(8.37 ? 2.70) h,respectively.AUC(0→T) of various tissues was (114.57 ?37.41),(11.57 ?7.16),(0.18 ?0.056),(2.86 ?0.42) and(0.079 ?0.017)?g/(h.g) or(?g/h.mL),respectively.CONCLUSION: The results indicate that musk in eye drop has a good permeability and high concentration in various intraocular tissues of rabbit after ocular instillation.