Jun Yin

Salvianolic Acid A, a Novel Matrix Metalloproteinase-9 Inhibitor, Prevents Cardiac Remodeling in Spontaneously Hypertensive Rats

Cardiac fibrosis is a deleterious consequence of hypertension which may further advance to heart failure and increased matrix metalloproteinase-9 (MMP-9) contributes to the underlying mechanism. Therefore, new therapeutic strategies to attenuate the effects of MMP-9 are urgently needed. In the present study, we characterize salvianolic acid A (SalA) as a novel MMP-9 inhibitor at molecular, cellular and animal level. We expressed a truncated form of MMP-9 which contains only the catalytic domain (MMP-9 CD), and used this active protein for enzymatic kinetic analysis and Biacore detection. Data generated from these assays indicated that SalA functioned as the strongest competitive inhibitor of MMP-9 among 7 phenolic acids from Salvia miltiorrhiza. In neonatal cardiac fibroblast, SalA inhibited fibroblast migration, blocked myofibroblast transformation, inhibited secretion of intercellular adhesion molecule (ICAM), interleukin-6 (IL-6) and soluble vascular cell adhesion molecule-1 (sVCAM-1) as well as collagen induced by MMP-9 CD. Functional effects of SalA inhibition on MMP-9 was further confirmed in cultured cardiac H9c2 cell overexpressing MMP-9 in vitro and in heart of spontaneously hypertensive rats (SHR) in vivo. Moreover, SalA treatment in SHR resulted in decreased heart fibrosis and attenuated heart hypertrophy. These results indicated that SalA is a novel inhibitor of MMP-9, thus playing an inhibitory role in hypertensive fibrosis. Further studies to develop SalA and its analogues for their potential clinical application of cardioprotection are warranted.

Schizandrin, an Antioxidant Lignan from Schisandra chinensis, Ameliorates Aβ1–42-Induced Memory Impairment in Mice

In the present study, we examined the effect of schisandrin (SCH) of Schisandra chinensis on the amyloid-beta1–42- (Aβ1–42-) induced memory impairment in mice and elucidated the possible antioxidative mechanism. Mice were intracerebroventricular (i.c.v.) injected with the aggregated Aβ1–42 and then treated with SCH (4, 12, and 36u2009mg/kg body weight) or donepezil (DPZ), a reference drug (0.65u2009mg/kg) by intragastric infusion for 14 days. Noncognitive disturbances and cognitive performance were evaluated by locomotor activity test, Y-maze test, and water maze test. Antioxidative enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) and levels of malondialdehyde (MDA), glutathione (GSH), and oxidized glutathione (GSSG) within the cerebral cortex and hippocampus of mice were measured to elucidate the mechanism. Our results showed that SCH significantly improved Aβ1–42-induced short-term and spatial reference memory impairments in Y-maze test and water maze test. Furthermore, in the cerebral cortex and hippocampus of mice, SOD and GSH-px activities, GSH level, and GSH/GSSG ratio were increased, and levels of MDA and GSSG were decreased by the treatment of SCH. These results suggest that SCH is a potential cognitive enhancer against Alzheimers disease through antioxidative action.

Cardio-protection of salvianolic acid B through inhibition of apoptosis network.

Targeting cellular function as a system rather than on the level of the single target significantly increases therapeutic potency. In the present study, we detect the target pathway of salvianolic acid B (SalB) in vivo. Acute myocardial infarction (AMI) was induced in rats followed by the treatment with 10 mg/kg SalB. Hemodynamic detection and pathological stain, 2-dimensional electrophoresis, MALDI-TOF MS/MS, Western blot, pathway identification, apoptosis assay and transmission electron microscope were used to elucidate the effects and mechanism of SalB on cardioprotection. Higher SalB concentration was found in ischemic area compared to no-ischemic area of heart, correlating with improved heart function and histological structure. Thirty-three proteins regulated by SalB in AMI rats were identified by biochemical analysis and were classified as the components of metabolism and apoptosis networks. SalB protected cardiomyocytes from apoptosis, inhibited poly (ADP-ribose) polymerase-1 pathway, and improved the integrity of mitochondrial and nucleus of heart tissue during AMI. Furthermore, the protective effects of SalB against apoptosis were verified in H9c2 cells. Our results provide evidence that SalB regulates multi-targets involved in the apoptosis pathway during AMI and therefore may be a candidate for novel therapeutics of heart diseases.

Gomisin A inhibits lipopolysaccharide-induced inflammatory responses in N9 microglia via blocking the NF-κB/MAPKs pathway

Gomisin A, one of the major dibenzocyclooctadiene lignans isolated from Schisandra chinensis Baill., has proved to possess a variety of pharmacological effects. The aim of the present study was to investigate the anti-inflammatory and neuroprotective effects of gomisin A as well as its potential molecular mechanisms. It was found that gomisin A not only inhibited the production of NO and PGE2 in a concentration-dependent manner but also suppressed the expressions of iNOS and COX-2 in LPS-stimulated N9 microglia without observable cytotoxicity. Gomisin A was also able to attenuate the mRNA expression and the production of pro-inflammatory factors TNF-α, IL-1β and IL-6. Moreover, LPS induced reactive oxygen species (ROS) production, NADPH oxidase activation, and gp91phox expression, which were markedly inhibited by gomisin A in microglia. Furthermore, the data showed that gomisin A significantly down-regulated the TLR4 protein expression, and inhibited nuclear transcription factor (NF)-κB and mitogen-activated protein kinases (MAPKs) signaling pathways. Additionally, gomisin A alleviated the cell death of SH-SY5Y neuroblastoma, rat primary cortical and hippocampal neurons induced by the conditioned-media from activated microglia. In summary, gomisin A may exert neuroprotective effects by attenuating the microglia-mediated neuroinflammatory response via inhibiting the TLR4-mediated NF-κB and MAPKs signaling pathways.

Matrix metalloproteinase-9 induces cardiac fibroblast migration, collagen and cytokine secretion: Inhibition by salvianolic acid B from Salvia miltiorrhiza

Cardiac fibroblasts play the key role in cardiac function and matrix metalloproteinases-9 (MMP-9) is a well known contributor to the development of myocardial remodeling. However, the direct regulation of MMP-9 on the function of cardiac fibroblasts and the underlying mechanism are far from elucidation. In the present research, recombinant protein encoding catalytic domain of MMP-9 (MMP-9 CD) was constructed and the function of neonatal cardiac fibroblasts was investigated by cell proliferation assay, migration assay, picrosirius red assay, multiplex cytokine assay and fibroblast phenotype detection. 200 nM MMP-9 CD stimulated cardiac fibroblasts migration (169.4±22.5% versus 100±0%, p<0.01), increased collagen synthesis (1.5±0.2 fold, p<0.05), up-regulated the secretion of ICAM (574.0±40.1 versus 268.5±8.6pg/ml, p<0.01), TNF-α (192.6±11.0 versus 14.4±1.8pg/ml, p<0.001), IL-6 (1500.9±70.2 versus 323.4±40.6pg/ml, p<0.001) and sVCAM-1 (30.3±4.3 versus 7.0±0.1 pg/ml, p<0.05) and down-regulated VEGF (436.5±148.9 versus 1034.3±28.1 pg/ml, p<0.05) significantly with modest effects on proliferation. Accompanying with these regulations, transition of fibroblasts to myofibroblast was confirmed by immunofluorescent stain of α-smooth muscle actin (α-SMA) with MMP-9 CD treatment. Furthermore, salvianolic acid B (SalB) inhibited the effects of MMP-9 CD significantly. In conclusion, our results provide evidence for a direct influence of MMP-9 on cardiac fibroblast migration, collagen and cytokine secretion, which can be attenuated by SalB.

miR-107 Activates ATR/Chk1 Pathway and Suppress Cervical Cancer Invasion by Targeting MCL1

MicroRNAs (miRNAs) are a class of single-stranded, non-coding RNAs of about 22 nucleotides in length. Increasing evidence implicates miRNAs may function as oncogenes or tumor suppressors. Here we showed that miR-107 directly targeted MCL1 and activated ATR/Chk1 pathway to inhibit proliferation, migration and invasiveness of cervical cancer cells. Moreover, we found that MCL1 was frequently up-regulated in cervical cancer, and knockdown of MCL1 markedly inhibited cancer cell proliferation, migration and invasion, whereas ectopic expression of MCL1 significantly enhances these properties. The restoration of MCL1 expression can counteract the effect of miR-107 on the cancer cells. Together, miR-107 is a new regulator of MCL1, and both miR-107 and MCL1 play important roles in the pathogenesis of cervical cancer. We have therefore identified a mechanism for ATR/Chk1 pathway which involves an increase in miR-107 leading to a decrease in MCL1. Correspondingly, our results revealed that miR-107 affected ATR/Chk1 signalling and gene expression, and implicated miR-107 as a therapeutic target in human cervical cancer. We also demonstrated that taxol attenuated migration and invasion in cervical cancer cells by activating the miR-107, in which miR-107 play an important role in regulating the expression of MCL1. Elucidation of this discovered MCL1 was directly regulated by miR-107 will greatly enhance our understanding of the mechanisms responsible for cervical cancer and will provide an additional arm for the development of anticancer therapies.

Deoxyschizandrin Isolated from the Fruits of Schisandra chinensis Ameliorates Aβ1–42-induced Memory Impairment in Mice

In the present study, we examined the effects of deoxyschisandrin (DS) from Schisandra chinensis on the amyloid-beta₁₋₄₂ (Aβ₁₋₄₂)-induced memory impairment in mice and investigated the possible antioxidative mechanism. Mice were given an intracerebroventricular (i. c. v.) injection with the aggregated Aβ₁₋₄₂ and then treated with DS (4, 12, and 36 mg/kg body weight) or donepezil (DPZ), a positive control drug (0.65 mg/kg), by intragastric infusion for 14 days. Non-cognitive disturbances and cognitive performance were evaluated by the locomotor activity, Y-maze, and water maze tests. Antioxidative enzyme activities including superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) and levels of malondialdehyde (MDA), glutathione (GSH), and oxidized glutathione (GSSG) within the cerebral cortex and hippocampus of mice were measured to investigate the mechanism. Our results showed that DS significantly improved Aβ₁₋₄₂-induced short-term and spatial memory impairments in the Y-maze and water maze tests. Furthermore, in the cerebral cortex and hippocampus of mice, the reduced activities of SOD and GSH-px, the GSH level, and the GSH/GSSG ratio were increased, and increased levels of MDA and GSSG were reduced following treatment with DS, although the improvement of GSH and the reduction of GSSG levels were not marked. These results suggest that DS is a potential cognitive enhancer in Alzheimers disease through its antioxidative action.

Dibenzocyclooctadiene lignans from Schisandra chinensis and their inhibitory activity on NO production in lipopolysaccharide-activated microglia cells

Four dibenzocyclooctadiene lignans, schisanchinins A-D, and 10 known compounds were isolated from the EtOAc extract of fruits of Schisandra chinensis (Turcz.) Baill. Structures of compounds 1-4 were elucidated using a combination of spectroscopic techniques, including MS, UV and IR, NMR ((1)H NMR, (13)C NMR, HMQC, HMBC). The stereochemistry of the chiral centers and the biphenyl configuration were determined using NOESY, as well as analysis of CD spectra. In vitro activity assays showed that 11 of the 14 compounds exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary murine BV2 microglia cells.

Extraction optimization of polysaccharides of Schisandrae Fructus and evaluation of their analgesic activity.

Polysaccharide from the Schisandrae Fructus (SFP) has been considered as the major effective component with many activities and high content. To obtain SFP more efficiently and clear up its analgesic activity, the three-factor, three-level orthogonal extracting test was designed to optimize the extraction condition based on the results of single-factor experiments. The optimal parameters were determined as extraction time of 1.5 h, extraction number of 4 times and ratio of water to raw material of 8-fold, respectively. The major monosaccharide component was identified by HPLC, and its characteristic was checked by UV and IR. The in vivo analgesic experiments revealed SFP significantly prolonged the latent period of writhing and reduced the writhing frequency produced by intraperitoneal injection of acetic acid, and prolonged the interval of licking of the hind paws on a hot-plate by mice. SFP could be a potential analgesic agent in the future according to our results.

The protective effects of ginsenoside Rg1 against hypertension target-organ damage in spontaneously hypertensive rats.

BackgroundAlthough a number of medicines are available for the management of hypertension, the organ damage induced by hypertension is not resolved. The aim of this study was to investigate the protection of ginsenoside Rg1 (Rg1) against vascular remodeling and organ damage in spontaneously hypertensive rats (SHR).MethodsMale SHR were treated with 5, 10 or 20u2009mg/kg Rg1 through intraperitoneal injection per day for 1u2009month. SHR or Wistar-Kyoto rats (WKY) receiving vehicle (saline) was used as control. Blood pressure detection and pathological stain, transmission electron microscope, immunohistochemical assay were used to elucidate the protection of Rg1.ResultsBlood pressures were not different between control SHR rats and Rg1 treated SHR rats, but Rg1 improved the aortic outward remodeling by lowering the lumen diameter and reducing the media thickness according the histopathological and ultrastructural detections. Rg1 also protected the retinal vessels against inward remodeling detected by immunohistochemical assay. Furthermore, Rg1 attenuated the target heart and kidney damage with improvement on cardiac and glomerular structure.ConclusionsThese results suggested that Rg1 held beneficial effects on vascular structure and further protected against the organ-damage induced by hypertension. These findings also paved a novel and promising approach to the treatment of hypertensive complications.