Ligation In Rats Research Articles

Endotoxemia-enhanced renal vascular reactivity to endothelin-1 in cirrhotic rats.

Hepatorenal syndrome (HRS), a severe complication of advanced cirrhosis, is defined as hypoperfusion of kidneys resulting from intense renal vasoconstriction in response to generalized systemic arterial vasodilatation. Nevertheless, the mechanisms have been barely investigated. Cumulative studies demonstrated renal vasodilatation in portal hypertensive and compensated cirrhotic rats. Previously, we identified that blunted renal vascular reactivity of portal hypertensive rats was reversed after lipopolysaccharide (LPS). This study was therefore conducted to delineate the sequence of renal vascular alternation and underlying mechanisms in LPS-treated cirrhotic rats. Sprague-Dawley rats were randomly allocated to receive sham surgery (Sham) or common bile duct ligation (CBDL). LPS was induced on the 28th day after surgery. Kidney perfusion was performed at 0.5 or 3 h after LPS to evaluate renal vascular response to endothelin-1 (ET-1). Endotoxemia increased serum ET-1 levels ( P < 0.0001) and renal arterial blood flow ( P < 0.05) in both Sham and CBDL rats. CBDL rats showed enhanced renal vascular reactivity to ET-1 at 3 h after LPS ( P = 0.026). Pretreatment with endothelin receptor type A (ETA) antagonist abrogated the LPS-enhanced renal vascular response in CBDL rats ( P < 0.001). There were significantly lower inducible nitric oxide synthase (iNOS) expression but higher ETA and phosphorylated extracellular signal-regulated kinase (p-ERK) expressions in renal medulla of endotoxemic CBDL rats ( P < 0.05). We concluded that LPS-induced renal iNOS inhibition, ETA upregulation, and subsequent ERK signaling activation may participate in renal vascular hyperreactivity in cirrhosis. ET-1-targeted therapy may be feasible in the control of HRS. NEW & NOTEWORTHY Hepatorenal syndrome (HRS) occurred in advanced cirrhosis after large-volume paracentesis or bacterial peritonitis. We demonstrated that intraperitoneal lipopolysaccharide (LPS) enhanced renal vascular reactivity to endothelin-1 (ET-1) in cirrhotic rats, accompanied by inducible nitric oxide synthase inhibition, endothelin receptor type A (ETA) upregulation, and subsequent extracellular signal-regulated kinase activation in renal medulla. Pretreatment with ETA antagonist abrogated the LPS-enhanced renal vascular response in common bile duct ligation rats. These findings suggest that further clinical investigation of ET-1-targeted therapy may be feasible in the control of HRS.

PBI-4050 Reduces Stellate Cell Activation and Liver Fibrosis through Modulation of Intracellular ATP Levels and the Liver Kinase B1/AMP-Activated Protein Kinase/Mammalian Target of Rapamycin Pathway.

Hepatic fibrosis is a major cause of morbidity and mortality for which there is currently no effective therapy. We previously showed that 2-(3-pentylphenyl)acetic acid (PBI-4050) is a dual G protein-coupled receptor GPR40 agonist/GPR84 antagonist that exerts antifibrotic, anti-inflammatory, and antiproliferative action. We evaluated PBI-4050 for the treatment of liver fibrosis in vivo and elucidated its mechanism of action on human hepatic stellate cells (HSCs). The antifibrotic effect of PBI-4050 was evaluated in carbon tetrachloride (CCl4)- and bile duct ligation-induced liver fibrosis rodent models. Treatment with PBI-4050 suppressed CCl4-induced serum aspartate aminotransferase levels, inflammatory marker nitric oxide synthase, epithelial to mesenchymal transition transcription factor Snail, and multiple profibrotic factors. PBI-4050 also decreased GPR84 mRNA expression in CCl4-induced injury, while restoring peroxisome proliferator-activated receptor γ (PPARγ) to the control level. Collagen deposition and α-smooth muscle actin (α-SMA) protein levels were also attenuated by PBI-4050 treatment in the bile duct ligation rat model. Transforming growth factor-β-activated primary HSCs were used to examine the effect of PBI-4050 and its mechanism of action in vitro. PBI-4050 inhibited HSC proliferation by arresting cells in the G0/G1 cycle phase. Subsequent analysis demonstrated that PBI-4050 signals through a reduction of intracellular ATP levels, activation of liver kinase B1 (LKB1) and AMP-activated protein kinase (AMPK), and blockade of mammalian target of rapamycin (mTOR), resulting in reduced protein and mRNA levels of α-SMA and connective tissue growth factor and restored PPARγ mRNA expression. Our findings suggest that PBI-4050 may exert antifibrotic activity in the liver through a novel mechanism of action involving modulation of intracellular ATP levels and the LKB1/AMPK/mTOR pathway in stellate cells, and PBI-4050 may be a promising agent for treating liver fibrosis.

Beneficial effects of cilostazol on liver injury induced by common bile duct ligation in rats: Role of SIRT1 signaling pathway.

Liver fibrosis is a health challenge requiring alternative therapeutic approaches. Cilostazol is a selective phosphodiesterase-3 inhibitor and possesses antioxidant, anti-inflammatory and antifibrotic properties. Sirtuin 1 (SIRT1) is a member of the silent information regulator 2 family. Cilostazol upregulates SIRT1 expression. Cilostazol protects against the cholestatic liver insults caused by bile duct obstruction. Involvement of SIRT1 pathway in this protective effect has not been studied yet. So, we hypothesized that SIRT1 signaling may have a role in cilostazol protective effects against bile duct ligation-induced liver damages. Rats were subjected to common bile duct ligation then treated with cilostazol (9mg/kg or 27mg/kg) in the presence or absence of specific SIRT1 inhibitor EX527. Cilostazol improved liver function, reduced inflammation, enhanced antioxidant status, ameliorated cholestatic liver injury and upregulated hepatic SIRT1. However, these protective effects were abrogated by EX527, suggesting that SIRT1 signaling may have a role in these effects. In conclusion, cilostazol in a dose-dependent way produced hepatoprotective effects via anti-inflammatory, antioxidant, antifibrotic effects which were mediated, in part, through SIRT1 upregulation.

Gastroprotective and digestive potential of an Ayurvedic asava–arishta preparation

Asavas and arishtas are considered as important Ayurvedic self-fermented dosage forms which are being used widely to promote health and well-being and for management of digestive and metabolic disorders. The present investigation was carried out to study the potential of an Ayurvedic polyherbal asava–arishta preparation (ZP) in gastroprotection, intestinal motility and gastric dyspepsia in experimental rodent models. The gastroprotective effect of ZP at doses 1.5, 3 and 6 ml/kg of body weight was studied using battery of animal models such as pyloric ligation in rats, intestinal transit time using charcoal meal test, gastric emptying and digestive stimulation action in rats. In addition, anti-spasmodic activity was studied using isolated guinea pig’s ileum. The role digestive enzymes such as pepsin, α-amylase and lipase were accessed by various enzymatic assays. A dose-dependent and statistically significant (p < 0.01) inhibitory effect on reducing gastric volume, free acidity, total acidity and ulcer index were observed in ZP treated animals as compared to the control. ZP also enhanced the mucin content of the gastric juice. Pre-treatment with ZP produced a dose-dependent effect in reducing intestinal motility, intestinal spasms and increased the gastric emptying time in rats. These observations validated the age old claims of ZP for its use as digestive tonic. Thus, results concluded that ZP is having potential to improve digestion and reduces recurrent digestive ailments.

3-Bromo-4,5-Dihydroxybenzaldehyde Protects Against Myocardial Ischemia and Reperfusion Injury Through the Akt-PGC1α-Sirt3 Pathway.

Natural marine products are useful candidates for the treatment of oxidative and inflammatory diseases, including myocardial ischemia. 3-bromo-4,5 - dihydroxybenzaldehyde (BDB), a natural bromophenol isolated from marine red algae, has been shown to display anti-microbial, anti-oxidative, anti-cancer, anti-inflammatory, and free radical scavenging activities. In this study, the potential protective effects of BDB against myocardial ischemia and reperfusion (IR) injury was investigated in an in vitro model mimicked by oxygen and glucose deprivation (OGD) in cardiomyocytes and in an in vivo model induced by coronary artery ligation in rats. The results showed that BDB attenuated the OGD-induced cytotoxicity in a dose-dependent manner, with no toxic effect when treated alone. BDB significantly decreased apoptosis and the cleavage of caspase-3 after OGD. We found that OGD-induced oxidative stress, as evidenced by increases of reactive oxygen species (ROS) and lipid peroxidation, as well as mitochondrial dysfunction, as measured by mitochondrial reporter gene, cytochrome c release and ATP synthesis, were markedly attenuated by BDB treatment. In addition, BDB increased the enzymatic activities of mitochondrial antioxidant enzymes, including IDH2, GSH-Px and SOD2. Western blot analysis showed that BDB increased Akt phosphorylation and upregulated the expression of Sirt3 and PGC1α after OGD. Furthermore, BDB-induced protection in cardiomyocytes was partially reversed by the Akt inhibitor and downregulation of PGC1α. BDB also attenuated myocardial contractile dysfunction and activated the Akt-PGC1α-Sirt3 pathway in vivo. All these data suggest that BDB protects against myocardial IR injury through activating the Akt-PGC1α-Sirt3 pathway.

Influence of neuropathic pain on nicotinic acetylcholine receptor plasticity and behavioral responses to nicotine in rats.

Tobacco smoking is particularly evident in individuals experiencing chronic pain. This complex relationship is poorly understood at both molecular and behavioral levels. Here, we describe experiments aimed at understanding whether a chronic pain state induces neuroadaptations into the brain or peripheral nerves that involve nicotinic acetylcholine receptors (nAChRs) and whether these neuroadaptations directly lead to increased vulnerability to nicotine addiction or to the development of coping strategies to relieve pain symptoms. We found that ligation of the rat L5 spinal nerve led to a dramatic downregulation in the mRNA expression levels of all nAChR subunits examined in dorsal root ganglia and a time-dependent downregulation of discrete subunits, particularly in the cingulate cortex and the amygdala. Spinal nerve ligation and sham-operated rats showed minor or no changes in patterns of acquisition and motivation for nicotine taking. Spinal nerve ligation rats also showed similar vulnerability to nicotine seeking as sham animals when reinstatement was induced by nicotine-associated cues, but failed to reinstate lever pressing when relapse was induced by nicotine priming. Spinal nerve ligation and sham rats were equally sensitive to nicotine-induced anxiety-like behavior and antinociception; however, nicotine produced a potent and long-lasting antiallodynic effect in spinal nerve ligation rats. These results demonstrate that chronic pain leads to plasticity of nAChRs that do not directly facilitate nicotine addictive behaviors. Instead, nicotine potently decreases allodynia, an effect that could lead to increased nicotine consumption in chronic pain subjects.

Upregulation of Krebs cycle and anaerobic glycolysis activity early after onset of liver ischemia.

The liver is a highly vascularized organ receiving a dual input of oxygenated blood from the hepatic artery and portal vein. The impact of decreased blood flow on glucose metabolism and how hepatocytes could adapt to this restrictive environment are still unclear. Using the left portal vein ligation (LPVL) rat model, we found that cellular injury was delayed after the onset of liver ischemia. We hypothesized that a metabolic adaptation by hepatocytes to maintain energy homeostasis could account for this lag phase. Liver glucose metabolism was characterized by 13C- and 1H-NMR spectroscopy and analysis of high-energy metabolites. ALT levels and caspase 3 activity in LPVL animals remained normal during the first 12 h following surgery (P<0.05). Ischemia rapidly led to decreased intrahepatic tissue oxygen tension and blood flow (P<0.05) and increased expression of Hypoxia-inducible factor 1-alpha. Intrahepatic glucose uptake, ATP/ADP ratio and energy charge level remained stable for up to 12 h after ligation. Entry of glucose in the Krebs cycle was impaired with lowered incorporation of 13C from [U-13C]glucose into glutamate and succinate from 0.25 to 12 h after LPVL. However, total hepatic succinate and glutamate increased 6 and 12 h after ischemia (P<0.05). Glycolysis was initially reduced (P<0.05) but reached maximum 13C-lactate (P<0.001) and 13C-alanine (P<0.01) enrichments 12 h after LPVL. In conclusion, early liver homeostasis stems from an inherent ability of ischemic hepatocytes to metabolically adapt through increased Krebs cycle and glycolysis activity to preserve bioenergetics and cell viability. This metabolic plasticity of hepatocytes could be harnessed to develop novel metabolic strategies to prevent ischemic liver damage.

Curcumin attenuates hepatic fibrosis and insulin resistance induced by bile duct ligation in rats.

Recent studies have strongly indicated the hepatoprotective effect of curcumin; however, the precise mechanisms are not well understood. This study aimed to determine the protective effect of curcumin on hepatic damage and hepatic insulin resistance in biliary duct ligated (BDL) fibrotic rat model. To accomplish this, male Wistar rats were divided into four groups (eight for each): sham group, BDL group, sham+Cur group and BDL+Cur group. The last two groups received curcumin at a dose of 100 mg/kg daily for 4 weeks. The mRNA/protein expression levels of Ras-related C3 botulinum toxin substrate 1 (Rac1), Rac1-GTP, dinucleotide phosphate oxidase 1 (NOX1), signal transducer and activator of transcription 3 (STAT3), suppressor of cytokine signalling 3 (SOCS3), insulin receptor substrate 1 (IRS1), extracellular signal-regulated kinase 1 (ERK1), specific protein 1 (Sp1) and hypoxia-inducible factor-1α (HIF-1α) were measured by real-time PCR and Western blotting, respectively. Fasting blood glucose, insulin and Leptin levels were determined and homoeostasis model assessment-estimated insulin resistance, as an index of insulin resistance, was calculated. Curcumin significantly attenuated liver injury and fibrosis, including amelioration of liver histological changes, reduction of hepatic enzymes, as well as decreased expression of liver fibrogenesis-associated variables, including Rac1, Rac1-GTP, NOX1, ERK1, HIF-1α and Sp1. Curcumin also attenuated leptin level and insulin resistance, which had increased in BDL rats (P<0·05). Furthermore, compared with the BDL group, we observed an increase in IRS1 and a decrease in SOCS3 and STAT3 expression in the curcumin-treated BDL group (P<0·05), indicating return of these parameters towards normalcy. In conclusion, Curcumin showed hepatoprotective activity against BDL-induced liver injury and hepatic insulin resistance by influencing the expression of some genes/proteins involved in these processes, and the results suggest that it can be used as a therapeutic option.

Involvement of GABAB receptor in the antihypersensitive effect in anterior cingulate cortex of partial sciatic nerve ligation model

The role of the GABAB receptor in the anterior cingulate cortex (ACC) of neuropathic pain is unclear. Injection of a GABAB receptor antagonist CGP35348 into the ACC induced mechanical hypersensitivity in normal rats. Activation of the GABAB receptor injected by a GABAB receptor agonist baclofen into the ACC attenuated mechanical hypersensitivity in partial sciatic nerve ligation (PSNL) rats. Co-microinjection of CGP35348 with a muscarinic M1 receptor agonist McN-A-343 into the ACC significantly inhibited McN-A-343-induced antihypersensitivity in PSNL rats. These results suggest that the GABAB receptor in the ACC contributes to mechanical hypersensitivity and is involved in muscarinic M1 receptor-mediated antihypersensitivity.

Tyrosine kinase SYK is a potential therapeutic target for liver fibrosis.

Spleen tyrosine kinase (SYK) plays a critical role in immune cell signaling pathways and has been reported as a biomarker for human hepatocellular carcinoma (HCC). We sought to investigate the mechanism by which SYK promotes liver fibrosis and to evaluate SYK as a therapeutic target for liver fibrosis. We evaluated the cellular localization of SYK and the association between SYK expression and liver fibrogenesis in normal, hepatitis B virus (HBV)-infected, hepatitis C virus (HCV)-infected and non-alcoholic steatohepatitis (NASH) liver tissue (n=36, 127, 22 and 30, respectively). A polymerase chain reaction (PCR) array was used to detect the changes in transcription factor (TF) expression in hepatic stellate cells (HSCs) with SYK knockdown. The effects of SYK antagonism on liver fibrogenesis were studied in LX-2 cells, TWNT-4 cells, primary human HSCs, and three progressive fibrosis/cirrhosis animal models, including a CCL4 mouse model, and diethylnitrosamine (DEN) and bile duct ligation (BDL) rat models. We found that SYK protein in HSCs and hepatocytes correlated positively with liver fibrosis stage in human liver tissue. HBV or HCV infection significantly increased SYK and cytokine expression in hepatocytes. Increasing cytokine production further induced SYK expression and fibrosis-related gene transcription in HSCs. Up-regulated SYK in HSCs promoted HSC activation by increasing the expression of specific TFs related to activation of HSCs. SYK antagonism effectively suppressed liver fibrosis via inhibition of HSC activation, and decreased obstructive jaundice and reduced HCC development in animal models. Conclusion: SYK promotes liver fibrosis via activation of HSCs and is an attractive potential therapeutic target for liver fibrosis and prevention of HCC development. (Hepatology 2018).

Shenfu Formula reduces cardiomyocyte apoptosis in heart failure rats by regulating microRNAs

Ethnopharmacological relevanceShenfu decoction consists of the water extract from the dried root or rootstalk of Panax ginseng C. A. Mey (Asian ginseng) and the lateral root of Aconitum carmichaeli Debx (Fuzi, Heishunpian in Chinese). Shenfu Formula has been used as a folk Chinese medicine for thousands of years. Recent studies have shown that Shenfu injection can enhance cardiac function and regulate arrhythmia. Aim of the studyShenfu Formula plays an important role in the treatment of heart failure. However, its microRNA-mediated mechanisms are still not fully understood. Thus, we established a heart failure model in rats to investigate the microRNA mechanism of Shenfu Formula in cardiac function and apoptosis. Materials and methodsThe heart failure animal model was established via left-anterior descending coronary artery ligation in rats. Seven days after surgery, Shenfu Formula was given to the heart failure rats, which were selected by echocardiography with an LVEF< 45%. After Shenfu Formula was given intragastrically for 30 days, blood samples were drawn, the heart was excised after echocardiography, and echocardiographic parameters and apoptosis-related proteins were further examined. Fas/Fas-L and Bcl-2/Bax proteins were analyzed by Western blot, and microRNAs were evaluated using Affymetrix GeneChip miRNA arrays. ResultsShenfu Formula increased the left ventricular ejection fraction, improved the hemodynamic index of heart failure rats, and decreased serum brain natriuretic peptide (BNP) levels. Shenfu Formula also decreased the positive rate of myocardial cells as detected by the TUNEL method and significantly suppressed caspase 3 expression. Moreover, we found that Shenfu Formula can regulate the initiative factors Fas/Fas-L in the intrinsic pathway and Bcl-2/Bax in the extrinsic apoptosis pathway to suppress apoptosis in heart failure rats. Finally, Shenfu Formula potentially alters the balance of microRNAs involved in activating and inhibiting apoptosis, ultimately suppressing apoptosis; this leads to changes in the gene expression profiles of microRNAs targets. ConclusionShenfu Granule can effectively improve cardiac function in heart failure rats, and the anti-apoptosis effects of Shenfu Formula are potential mechanisms for inhibiting heart failure.

Comperative Investigation of Structure of Male Genital System of Ductus Deferens Ligation in Rats

Objective: We investigated structural and morphological changes in pre-pubertal and pubertal rat testis and ductus deferens after unilateral vasectomy. Vasectomy is reliable and popular male contraception method, applied widely in the world. Methods: Six pre-pubertal and 6 pubertal male Wistar albino rats were divided into four groups. Unilateral ductus deferens ligation was performed on right ductus deferens of each rat. Right testis and ductus deferens tissues were evaluated as ligation group while left tissues were control groups. Two months after operation, the vas deferens and testes removed to obtain paraffin block sections and morphometric studies carried out with light microscopy. Hematoxylin-eosin staining and vascular endothelial growth factor (VEGF) immunohistochemically staining were applied. Results: Structural and morphological changes and decrease in spermatogenesis process have been observed at testis and ductus deferens tissues of all vasectomized rat. The seminiferous epithelium and the seminiferous tubule diameter were thickened. Degenerative changes have been observed at the epithelial structure of Ductus deferens and among muscle fibers forming the muscle of the Ductus deferens. Moreover, in pre-pubertal and pubertal vasectomized rat VEGF immunoreactivity was not observed in seminiferous tubule. Conclusion: The unilateral ligation operation can cause damage at ductus deferens and testis tissue in the pre-pubertal and pubertal period.

Rivaroxaban, a direct inhibitor of factor Xa, attenuates myocardial ischemia-reperfusion injury in rats at therapeutic concentrations

Acute myocardial infarction is a leading cause of death worldwide. Although highly beneficial, reperfusion of myocardium is associated with reperfusion injury. Indirect pharmacologic inhibition of factor Xa by fondaparinux has been shown to attenuate myocardial ischemia-reperfusion (I/R) injury via the activation of the SAFE pathway. The link between the inhibition of factor Xa and the activation of this cardioprotective pathway remains unclear. To study the effect of a direct inhibitor of factor Xa, rivaroxaban (RIV), on myocardial I/R injury. We investigated the ability of RIV to prevent I/R injury in a model of transient coronary ligation in rats. 40 min of myocardial ischemia was followed by 120 min of reperfusion. RIV (3 mg/kg) was injected intraperitoneally (IP) 10 min before reperfusion or given per os (PO) 1 hour before reperfusion. Infarct size was assessed after 120 min of reperfusion. RIV concentrations were measured after both administration protocols. Myocardial tissues were collected at 30 min reperfusion for western-blots analysis. RIV decreased infarct size by 19% when administrated IP (44.1% vs. 54.2% in RIV-treated rats and controls respectively, P < 0.05) and by 21% when administrated PO (42.9% vs. 54.2% in RIV-treated rats and controls respectively, P < 0.05). After IP administration, concentrations of RIV where higher than after PO administration (7244.3 ± 1853 ng/mL vs. 387.7 ± 152.3 ng/mL respectively). There was no effect of RIV on the phosphorylation of STAT-3, GSK-3β, AKT and ERK1/2. RIV decreased myocardial I/R injury in rats at concentrations similar to those known as antithrombotic in human therapeutics. Unlike FDX, this protective effect was not mediated through the activation of the cardioprotective pathways RISK and SAFE.

Chronic pain impairs cognitive flexibility and engages novel learning strategies in rats.

Cognitive flexibility, the ability to adapt behavior to changing outcomes, is critical to survival. The prefrontal cortex is a key site of cognitive control, and chronic pain is known to lead to significant morphological changes to this brain region. Nevertheless, the effects of chronic pain on cognitive flexibility and learning remain uncertain. We used an instrumental paradigm to assess adaptive learning in an experimental model of chronic pain induced by tight ligation of the spinal nerves L5/6 (spinal nerve ligation model). Naive, sham-operated, and spinal nerve ligation (SNL) rats were trained to perform fixed-ratio, variable-ratio, and contingency-shift behaviors for food reward. Although all groups learned an initial lever-reward contingency, learning was slower in SNL animals in a subsequent choice task that reversed reinforcement contingencies. Temporal analysis of lever-press responses across sessions indicated no apparent deficits in memory consolidation or retrieval. However, analysis of learning within sessions revealed that the lever presses of SNL animals occurred in bursts, followed by delays. Unexpectedly, the degree of bursting correlated positively with learning. Under a variable-ratio probabilistic task, SNL rats chose a less profitable behavioral strategy compared with naive and sham-operated animals. After extinction of behavior for learned preferences, SNL animals reverted to their initially preferred (ie, less profitable) behavioral choice. Our data suggest that in the face of uncertainty, chronic pain drives a preference for familiar associations, consistent with reduced cognitive flexibility. The observed burst-like responding may represent a novel learning strategy in animals with chronic pain.

Binding Characteristics and Analgesic Effects of Mirogabalin, a Novel Ligand for the α2δ Subunit of Voltage-Gated Calcium Channels.

Mirogabalin ([(1R,5S,6S)-6-(aminomethyl)-3-ethylbicyclo[3.2.0]hept-3-en-6-yl]acetic acid), a novel ligand for the α2δ subunit of voltage-gated calcium channels, is being developed to treat pain associated with diabetic peripheral neuropathy and postherpetic neuralgia. In the present study, we investigated the in vitro binding characteristics and in vivo analgesic effects of mirogabalin compared with those of pregabalin, a standard α2δ ligand. Mirogabalin showed potent and selective binding affinities for the α2δ subunits, while having no effects on 186 off-target proteins. Similar to pregabalin, mirogabalin did not show clear subtype selectivity (α2δ-1 vs. α2δ-2) or species differences (human vs. rat). However, in contrast to pregabalin, mirogabalin showed greater binding affinities for human α2δ-1, human α2δ-2, rat α2δ-1, and rat α2δ-2 subunits; further, it had a slower dissociation rate for the α2δ-1 subunit than the α2δ-2 subunit. Additionally, in experimental neuropathic pain models, partial sciatic nerve ligation rats and streptozotocin-induced diabetic rats, mirogabalin showed more potent and longer lasting analgesic effects. In safety pharmacological evaluations, mirogabalin and pregabalin inhibited rota-rod performance and locomotor activity in rats; however, the safety indices of mirogabalin were superior to those of pregabalin. In conclusion, mirogabalin shows potent and selective binding affinities for the human and rat α2δ subunits, and slower dissociation rates for the α2δ-1 subunit than the α2δ-2 subunit. It shows potent and long-lasting analgesic effects in rat models of neuropathic pain, and wider safety margins for side effects of the central nervous system. These properties of mirogabalin can be associated with its unique binding characteristics.

Rat inferior caval vein (ICV) ligature and particular new insights with the stable gastric pentadecapeptide BPC 157

Rat inferior caval vein (ICV) ligation (up to the right ovarian vein (ROV)) commonly represents a recapitulation of Virchow: with ligation leading to vessel injury, stasis, thrombosis and hemodynamic changes. We revealed that BPC 157’s therapy collectively attenuated or counteracted all these events and the full syndrome. MethodsWe applied BPC 157 (10 μg, 10 ng/kg) as an early regimen or as a delayed therapy. Assessment includes gross assessment by microcamera; microscopy, venography, bleeding, blood pressure, ECG, thermography, MDA and NO-level in plasma and ICV, and gene expression. ResultsDirect vein injury, thrombosis, thrombocytopenia, prolonged bleeding were all counteracted. Also, rapid presentation of collaterals and redistribution of otherwise trapped blood volume (bypassing through the left ovarian vein (LOV) and other veins), with venous hypertension, arterial hypotension and tachycardia counteraction were shown. BPC 157-rats presented raised plasma NO-values, but normal MDA-values; in ICV tissue reverted low NO-values and counteracted increased MDA-levels. Altered expression of EGR, NOS, SRF, VEGFR and KRAS in ICV, ROV and LOV revealed increased or decreased levels, while some genes continuously remained unchanged. ConclusionAs a new insight, BPC 157 application largely attenuated or even completely eliminated all consequences of ICV ligation in rats.

Modulation of transport and metabolism of bile acids and bilirubin by chlorogenic acid against hepatotoxicity and cholestasis in bile duct ligation rats: involvement of SIRT1-mediated deacetylation of FXR and PGC-1α.

The purpose of the present study was to investigate the effect and potential mechanism of chlorogenic acid (CA) on liver injury induced by cholestasis in a rat model of bile duct ligation (BDL). Rats received vehicle or CA (20, 50, or 100mg/kg per day) orally for 3days. On the 4th day, the rats underwent sham or BDL surgery, and were orally administrated vehicle or CA for 3 or 7days. mRNA and protein expression levels were evaluated by qRT-PCR and western blot. After BDL, plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and total bile acids (TBA) were increased and typical pathological changes were observed in liver morphology. Hepatic uptake transporters (Ntcp, Oatp 1a4, and Oatp 1b2) were downregulated, while efflux transporters (Bsep and Mrp 2/3/4) were upregulated. BDL inhibited the expressions of Cyp7a1, Cyp8b1, and Cyp27a1 and induced Ugt1a1. CA treatment decreased ALT, AST, TBIL, and TBA (P<0.05) and alleviated the liver pathological changes. The degree of expression changes in the transporters and enzymes was extended by CA (P<0.05). SIRT1 protein was induced after CA treatment in BDL rats. Chlorogenic acid attenuated hepatotoxicity and cholestasis by decreasing the uptake and synthesis of bilirubin and bile acids and accelerating the metabolism and efflux of bilirubin and bile acids.

Luteolin Could Improve Cognitive Dysfunction by Inhibiting Neuroinflammation.

Neuroinflammation and oxidative stress play an important role in cognition deficit following chronic cerebral hypoperfusion (CCH). Luteolin, a natural flavonoid found in many plants, is known for a variety of pharmacological activities, such as its anti-inflammatory, anti-allergy, urate, anti-tumor, antibacterial, and antiviral effects. To assess whether luteolin could prevent CCH-induced cognitive dysfunction, through its anti-inflammatory and anti-oxidative-stress effects, we used enzyme-linked immunosorbent assays, enzyme activity assays, behavioral methods, immunohistochemistry, and electrophysiology to detect neuroinflammation and oxidative stress, cognition alterations, and long-term potential (LTP), in a bilateral common carotid arteries ligation (2VO) rat model. We demonstrated that CCH increased tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 6 (IL-6), and malondialdehyde (MDA), and decreased superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels. Further, it caused microglia over-activation and astrogliosis, learning and short-term memory dysfunction, and an LTP deficit. Luteolin treatment reversed CCH-induced changes. Specifically, luteolin prevented the increase of TNF-α and IL-1β, IL-6, and MDA, improved the activity of SOD and GPx, inhibited microglia over-activation and astrogliosis (particularly in the hippocampus and cortex), and ameliorated learning and short-term memory dysfunction, and LTP deficit. Thus, our study suggested that luteolin could be a preferable anti-inflammatory agent to protect cognitive function and synaptic plasticity following CCH. Luteolin could also be putative therapeutic candidate for other inflammation-related brain diseases.

Melatonin prevented spatial deficits and increases in brain asymmetric dimethylarginine in young bile duct ligation rats.

Bile duct ligation (BDL) in young rats can cause impaired liver function and cognition deficits. Nitric oxide is implicated in hepatic encephalopathy and is also involved in cognition. In this study, we examined the role of brain asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, in young BDL rats with spatial deficits. Young male Sprague-Dawley rats aged 17 days were assigned to four groups: laparotomy (SHAM), laparotomy plus 5 mg melatonin delivered through a pellet (SHAMM) for 4 weeks, BDL for 4 weeks, and BDL plus 5 mg melatonin delivered through a pellet (BDLM) for 4 weeks. Their spatial memory was assessed using a Morris water-maze task. Plasma and brains were collected for biochemical and ADMA analyses. We found that the BDL group had significantly elevated levels of ADMA in the plasma, the prefrontal cortex, and the dorsal hippocampus, and worse spatial performance than that of the control groups. Melatonin administration prevented an increase in the ADMA levels in the plasma, prefrontal cortex, and dorsal hippocampus, and prevented spatial deficits in BDL rats. In addition, melatonin maintained brain-derived neurotrophic factor in the dorsal hippocampus at a level comparable with controls. We concluded that melatonin is effective in preventing spatial deficits and decreasing ADMA levels in the plasma, prefrontal cortex, and dorsal hippocampus in young BDL rats. Brain ADMA levels might play a role in BDL-induced spatial deficits.

Carnosic Acid Alleviates BDL-Induced Liver Fibrosis through miR-29b-3p-Mediated Inhibition of the High-Mobility Group Box 1/Toll-Like Receptor 4 Signaling Pathway in Rats.

Fibrosis reflects a progression to liver cancer or cirrhosis of the liver. Recent studies have shown that high-mobility group box-1 (HMGB1) plays a major role in hepatic injury and fibrosis. Carnosic acid (CA), a compound extracted from rosemary, has been reported to alleviate alcoholic and non-alcoholic fatty liver injury. CA can also alleviate renal fibrosis. We hypothesized that CA might exert anti-liver fibrosis properties through an HMGB1-related pathway, and the results of the present study showed that CA treatment significantly protected against hepatic fibrosis in a bile duct ligation (BDL) rat model. CA reduced the liver expression of α-smooth muscle actin (α-SMA) and collagen 1 (Col-1). Importantly, we found that CA ameliorated the increase in HMGB1 and Toll-like receptor 4 (TLR4) caused by BDL, and inhibited NF-κB p65 nuclear translocation in fibrotic livers. In vitro, CA inhibited LX2 cell activation by inhibiting HMGB1/TLR4 signaling pathway. Furthermore, miR-29b-3p decreased HMGB1 expression, and a dual-luciferase assay validated these results. Moreover, CA down-regulated HMGB1 and inhibited LX2 cell activation, and these effects were significantly counteracted by antago-miR-29b-3p, indicating that the CA-mediated inhibition of HMGB1 expression might be miR-29b-3p dependent. Collectively, the results demonstrate that a miR-29b-3p/HMGB1/TLR4/NF-κB signaling pathway, which can be modulated by CA, is important in liver fibrosis, and indicate that CA might be a prospective therapeutic drug for liver fibrosis.