Inflammatory response in rat kidney with contrast-induced nephropathy

AIM：To observe the expression of tumor necrosis factor α (TNF-α) and nuclear factor κB (NF-κB) in the renal tissue of the rats with contrast-induced nephropathy (CIN). METHODS：Male Sprague-Dawley rats (n=96) were randomly divided into control group (n=48) and CIN group (n=48). The model rats in CIN group were intravenously injected with iodinated contrast media (76% compound diatrizoate injection,10 mL/kg), while the rats in control group were injected with the same volume of saline. Six rats in each group were sacrificed at 6 h, 12 h, 24 h, 48 h, 72 h, 5 d, 10 d and 15 d after intravenous injection, respectively, and the blood and kidney samples of the rats were obtained. The renal tubular injury was assessed by histological examination (HE staining). The expression of kidney injury molecule-1 (KIM-1), TNF-α and NF-κB at mRNA and protein levels in the renal tissues were semiquantitatively measured by the methods of RT-PCR and immunohistochemistry, respectively. The correlations between the expression of TNF-α, NF-κB and tubular injury score, KIM-1 expression in renal tissue of CIN group were analyzed. RESULTS：The levels of serum creatinine (SCr) and blood urea nitrogen (BUN) in control group were not changed between different time points (P>0.05). The levels of SCr and BUN in CIN group displayed significant increases at different time points (except 15 d) compared with control group (P<0.05). The renal tubular injury score in CIN group was significantly higher at all time points than that in control group (P<0.05). The expression of KIM-1, TNF-α and NF-κB at mRNA and protein levels up-regulated significantly at 6 h and the peaking of KIM-1 expression was at 24 h, while the peaking of TNF-α and NF-κB expression was at 48 h in CIN group. The expression of KIM-1,TNF-α and NF-κB was significantly increased in CIN group compared with control group except at 15 d (P<0.05). The expression of TNF-α and NF-κB at mRNA and protein levels showed close correlations with renal tubular injury score (r=0.843, 0.758, 0.743 and 0.707, P<0.05). The expression of TNF-α and NF-κB at mRNA and protein levels was also positively correlated with KIM-1 expression (r=0.863, 0.807, 0.839 and 0.855, P<0.05). CONCLUSION：The expression of TNF-α and NF-κB at mRNA and protein levels in the renal tissues of CIN group is up-regulated and is closely related with renal tubular injury, indicating that the inflammatory response is involved in the pathogenesis of CIN.     

Protective effect of all-trans retinoic acid pretreatment against rat intestinal injury induced by hepatic inflow occlusion

AIM：To investigate the effect of all-trans retinoic acid (ATRA) on the intestinal injury induced by hepatic inflow occlusion (HIO) and its mechanisms. METHODS：Thirty-two male Sprague-Dawley rats were randomly divided into four groups: sham group, HIO group, dimethyl sulfoxide (DMSO) + HIO group and ATRA (15 mg·kg-1·d-1) + HIO group. The hepatoduodenal ligament of the rats in the latter three groups was occluded (Pringle manoeuvre) by clamp for 30 min. After reperfusion for 2 h by release of the clamp, samples of distal ileum and serum were collected. Histological changes and Chiu’s scores of the ileac mucosa were evaluated under light microscope. Serum content of diamine oxidase (DAO), and ileac tissue levels of malonaldehyde (MDA) and superoxide dismutase (SOD) were analyzed by colorimetry. Serum concentrations of interleukin (IL)-1β and tumor necrosis factor (TNF)-α were evaluated by enzyme-linked immunosorbent assay method. Expression of manganese superoxide dismutase (MnSOD) in cytoplasm and nuclear factor kappa B (NF-κB) p65 in nucleus was assessed by Western blotting. RESULTS：Compared with sham group and DMSO+HIO group, ATRA significantly reduced the mucosal Chiu’s scores, the serum content of DAO and the tissue level of MDA, enhanced the serum activity of SOD and the protein expression of MnSOD, and decreased the content of NF-κB p65 in nucleus (all P<0.05). Subsequently, ATRA significantly reduced the levels of TNF-α and IL-1β in serum (P<0.05). CONCLUSION：ATRA can attenuate rat intestinal injury induced by HIO through improving the antioxidant capacity of tissue, inhibiting the activation of NF-κB and suppressing the overexpression of pro-inflammatory factors.     

Effect of salidroside on alcohol-injuced hepatic injury in rats

AIM:To investigate the effect of salidroside on alcoholic hepatic injury in rats. METHODS:The SD rats were randomly divided into 5 groups:negative control group, model group, bifendate group, and low-and high-dose salidroside groups. The rats in model group were administered with 56% alcohol, while the rats in negative control group was administered with saline. The rats in bifendate group and salidroside groups were administered with corresponding drugs every day. The blood and the liver tissues were collected to measure triacylglycerol (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA) and superoxide dismutase (SOD). The pathological changes of the liver tissues were observed with HE staining. Tumor necrosis factor-α (TNF-α) and nuclear factor-κB (NF-κB) were measured by ELISA and the protein and mRNA expression levels of TNF-α and NF-κB were detected by Western blot and RT-PCR. RESULTS:Compared with model group, the levels of TG, ALT, AST, MDA, TNF-α and NF-κB were reduced, while the activity of SOD was enhanced in salidroside group (P<0.05). The liver tissue injury was significantly attenuated. CONCLUSION:Salidroside improves the pathological changes, reduces inflammation, increases the activity of antioxidant enzymes and reduces lipid peroxidation in the liver with alcohol-induced injury. This effect may be related to regulating the NF-κB-mediated inflammatory responses.     

Hypoxia-inducible factor-1α attenuates myocardial inflammatory injury induced by ischemia and reperfusion in rats

AIM:To investigate the role of hypoxia-inducible factor-1α (HIF-1α) stable expression in myocardial inflammatory injury induced by ischemia and reperfusion (I/R) in rats. METHODS:Male Wistar rats were randomly divided into 4 groups:sham operation (sham) group, I/R group, HIF-1α stabilizer dimethyloxalyl glycine (DMOG)+I/R group and HIF-1α inhibitor YC-1+I/R group. The protein expression of myocardial Toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) was determined by Western blot. The mRNA levels of interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), IL-6, TLR4 and NF-κB were detected by real-time PCR. The myeloperoxidase (MPO) activity in the myocardial tissues was measured. HE staining was used to observe the infiltration of inflammatory cells. RESULTS:HIF-1α decreased the infiltration of inflammatory cells, the MPO activity, and the mRNA levels of inflammatory factors IL-1β, IL-6 and TNF-α in the myocardial tissues. HIF-1α also reduced the expression of TLR4 and NF-κB at mRNA and protein levels (P<0.05). CONCLUSION:The stable expression of HIF-1α has an anti-inflammatory effect on the myocardial tissues after I/R injury in rats. The mechanism may be related to the inhibition of TLR4/NF-κB signaling pathway.     

Effects of rosiglitazone on expression of SOCS1/SOCS3 and inflammatory reaction in RAW 264.7 cell-derived foam cells

AIM: To investigate whether perioxisome proliferator-activated receptor γ (PPARγ) ligand rosiglitazone regulates suppressor of cytokine signaling 1 (SOCS1) and SOCS3 expression as well as pro-inflammatory/anti-inflammatory responses in RAW 264.7 cell-derived foam cells. METHODS: The concentrations of TNF-α, IL-6 and IL-10 in the cultured supernatant of RAW 264.7 cell-derived foam cells were detected by ELISA, and the ratios of TNF-α/IL-10 and IL-6/IL-10 were calculated. RT-PCR and Western blotting were used to analyze the effects of rosiglitazone on the expression of SOCS1 and SOCS3 at mRNA and protein levels. RESULTS: The concentrations of TNF-α, IL-6 and IL-10, and ratios of TNF-α/IL-10 and IL-6/IL-10 in foam cell group were obviously higher than those in control group, but the concentrations of the above factors in oxidized low-density lipoprotein (ox-LDL) +rosiglitazone group were apparently lower than those in foam cell group. The expression of SOCS1 and SOCS3 at mRNA and protein levels in oxLDL+rosiglitazone group was apparently higher than that in control and foam cell group. CONCLUSION: PPARγ ligand rosiglitazone up-regulates the expression of SOCS1 and SOCS3 at mRNA and protein levels and regulates the balance of pro-inflammatory/anti-inflammatory responses in RAW 264.7 cell-derived foam cells.     

CB2 receptor agonist JWH133 exerts protective effects on rat model of paraquat-induced acute lung injury

AIM: To study the protective effects of cannabinoid CB2 receptor agonist JWH133 on rat acute lung injury induced by paraquat (PQ).METHODS: Male Sprague-Dawley rats (n=72) were randomly divided into 4 groups. PQ group: PQ was administered intraperitoneally at the dose of 20 mg/kg; Low-dose JWH133 pretreatment group (L-JWH133 group): JWH133 (5 mg/kg, ip) was administered 1 h before PQ exposure; high-dose JWH133 pretreatment group (H-JWH133 group): JWH133 (20 mg/kg, ip) was administered 1 h before PQ exposure; control group: 1 mL saline was administered intraperitoneally. Arterial blood, bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected at 8 h, 1 d and 3 d after PQ exposure. PaO2 and the levels of TNF-α and IL-1β in BALF were measured via blood gas analyzer and ELISA, respectively. The pathological changes and lung injury scores were assessed at 3 d after PQ exposure. NF-κB and AP-1 protein levels were also determined by Western blotting.RESULTS: The decrease in PaO2, structural injury of the lung tissues, interstitial pulmonary edema, and the increase in IL-1β and TNF-α in BALF were observed in PQ-treated rats compared with control group. JWH133 pretreatment reduced the degree of lung tissue injury, decreased the levels of IL-1β and TNF-α in BALF and the NF-κB and AP-1 protein expression in the lung tissue compared with PQ group, especially in H-JWH133 group. CONCLUSION: CB2 receptor agonist JWH133 inhibits NF-κB and AP-1 protein expression in the lung tissues, and reduces the secretion of IL-1β and TNF-α in BALF after paraquat exposure, thus attenuating paraquat-induced acute lung injury.     

Effect of hydrogen sulfide on myocardial fibrosis and PPARγ and NF-κB expression in rat model of diabetes

AIM: To explore the effects of hydrogen sulfide (H₂S) on the myocardial fibrosis in a rat model of diabetes and its mechanism.METHODS: Single intraperitoneal injection of streptozotocin (STZ) was utilized to establish a rat model of diabetes. Sodium hydrosulfide was used as an exogenous donor of hydrogen sulfide. Male SD rats were randomly divided into control group, STZ group, STZ+H₂S group and H₂S group. Eight weeks later, HE and VG staining methods were used to observe the collagen distribution and collagen volume fraction was measured by image analysis. The expression levels of type I collagen, PPARγ and NF-κB in the cardiac tissues were determined by Western blotting.RESULTS: Compared with control group, collagen distribution and the expression levels of type I collagen and NF-κB in the cardiac tissues were markedly increased (P<0.05), while PPARγ was significantly decreased in STZ group (P<0.05), but these indexes were reversed significantly in STZ+H₂S group (P<0.05). The expression levels of type I collagen, PPARγ and NF-κB had no significant difference between H₂S group and control group.CONCLUSION: Hydrogen sulfide attenuates cardiac fibrosis in diabetic rats, and its mechanism may be related to PPARγ-NF-κB signaling pathway.     

Effects of Huaiyu decoctum on serum concentrations of TNF-α, IL-6 and IL-10 in rats after anorectal operation

ATM: To investigate the effects of Huaiyu decoctum on the serum concentrations of TNF-α, IL-6 and IL-10 in rats after anorectal operation. METHODS: Sprague-Dawley rats (n=40) were randomly divided into 4 groups:normal group, model group, low-dose Huaiyu decoctum group and high-dose Huaiyu decoctum group. The concentrations of TNF-α, IL-6 and IL-10 in the rat serum were measured by ELISA. The pathologic changes of the anorectal tissues were observed under microscope with HE staining. The protein expression of ICAM-1, VCAM-1 and NF-κB was determined by Western blotting. RESULTS: After Huaiyu decoctum administration, TNF-α and IL-6 concentrations in the serum were significantly decreased, and IL-10 concentration was increased as compared with model group. Moreover, Huaiyu decoctum markedly attenuated edema and hyperemia in the rats after anorectal operation. The protein expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and NF-κB in the anorectal tissues was obviously inhibited by Huaiyu decoctum treatment. CONCLUSION: Huaiyu decoctum improves the recovery of anorectal tissues after operation by decreasing the serum concentrations of TNF-α, IL-6 and IL-10, and reducing the protein expression of ICAM-1, VCAM-1 and NF-κB in the anorectal tissues.     

Expression of calprotectin in rats with renal ischemia-reperfusion injury

AIM: To investigate the expression of calprotectin(CALP) in the rats with renal ischemia-reperfusion injury(IRI). METHODS: Male Sprague-Dawley rats were randomly divided into sham operation and IRI group(n=25 in each group). Blood samples and the kidneys were obtained at 6 h, 12 h, 24 h, 48 h and 72 h after reperfusion. The pathological changes of the kidneys were observed. The serum concentrations of blood urea nitrogen(BUN) and serum creatinine(SCr) were measured. The serum levels of CALP, tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) were detected by ELISA, and the expression of CALP, Toll-like receptor 4(TLR4) and NF-κB p65 in the renal tissues were determined by the methods of immunohistochemistry and Western blot. RESULTS: Different serial ischemia changes were observed in the renal tissues, mainly in the renal tubular epithelial cells and the mesenchyma, with the infiltration of inflammatory cells. The serum levels of BUN, SCr, CALP, TNF-α and IL-6 in IRI group were markedly increased as compared with sham group(P<0.05). The protein expression of CALP, TLR4 and NF-κB p65 in the renal tubular epithelial cells in IRI group was greatly enhanced in comparison with that in sham group(P<0.05). CONCLUSION: The serum concentrations of CALP, TNF-α and IL-6, and the protein expression levels of CALP, TLR4 and NF-κB p65 in the renal tissue are significantly increased in the rats with IRI, suggesting that calprotectin plays an important role in the inflammation in rats with IRI.     

Effect of Yiqi Huayu Huatan decoction on expression of KLF15, HMGB1, NF-κB and its downstream inflammatory factors in rats with UUO-induced renal interstitial fibrosis

AIM: To observe the effect of Yiqi Huayu Huatan decoction (YHHD) on unilaterral ureteral obstruction (UUO)-induced renal interstitial fibrosis in rats, and to investigate the possible mechanism. METHODS: Female SD rats (n=48) were randomly divided into sham group, model group, telmisartan group, and low-, middle-and high-dose YHHD groups, with 8 rats in each group. The UUO model rats was established by ligating left ureter. The rats in sham group and model group were treated with equal volume of normal saline, others were treated with the corresponding drugs daily. After 12 weeks, the rats were sacrificed. The serum samples were collected for determining the concentrations of cystatin C (Cys-C) and uric acid (UA). The morphological changes of the renal tissue were observed by PAS staining. The collagen fiber was observed by Masson staining. The mRNA expression of Krüppel-like factor 15 (KLF15), high-mo-bility group box protein 1 (HMGB1), nuclear factor-κB (NF-κB), IκB, monocyte chemotactic protein-1 (MCP-1), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), fibronectin (FN), collagen type I (Col I) and Col-Ⅳ was detected by real-time PCR. The protein expression of KLF15, HMGB1 and NF-κB was detected by Western blot. The protein expression of MCP-1 was determined by the method of immunohistochemistry. RESULTS: Compared with sham group, the deposition rate of collagen fibers and the concentration of Cys-C in model group were significantly increased (P<0.05), the mRNA and protein expression of KLF15 was significantly down-regulated (P<0.05), while the mRNA expression of HMGB1, NF-κB, IκB, MCP-1, IL-1β, TNF-α, FN, Col I and Col Ⅳ and the protein expression of HMGB1, NF-κB and MCP-1 were significantly up-regulated (P<0.05). Compared with model group, the deposition rates of collagen fibers in middle-and high-dose YHHD groups and telmisartan group were significantly decreased (P<0.05), with down-regulated protein expression of HMGB1 and NF-κB and mRNA expression of IL-1β and TNF-α (P<0.05). The protein expression of KLF15 was significantly up-regulated in high-dose YHHD group and telmisartan group (P<0.05), while the protein expression of MCP-1 and the mRNA expression of FN were significantly down-regulated (P<0.05). The mRNA expression of KLF15 was significantly up-regulated in high-dose YHHD group (P<0.05), while the mRNA expression of MCP-1, Col I and Col IV was significantly down-regulated (P<0.05). The mRNA expression of NF-κB and IκB was significantly down-regulated and the concentration of Cys-C was significantly decreased in each dose of YHHD groups and telmisartan group (P<0.05). No significant difference of UA level among the groups was observed. CONCLUSION: YHHD alleviates renal interstitial fibrosis in a dose-dependent manner, and YHHD at high dose shows the most obvious effect. The mechanism may be associated with the up-regulation of KLF15 and the down-regulation of HMGB1, NF-κB and its downstream inflammation-related factors in the renal tissue.     

Effects of icariin preconditioning on inflammatory responses in myocar-dial ischemia-reperfusion injury

AIM:To observe the effects of icariin on myocardial ischemia-reperfusion injury. METHODS:The left anterior descending coronary artery was ligated for 30 min and then loosened for 2 h to establish the rat model of myocardial ischemia-reperfusion injury. Forty-eight healthy adult male SD rats weighing 250~300 g were randomly divided into sham group, model group, low-, middle-and high-dose icariin groups, and aspirin group. The morphological changes of the myocardium were observed by HE staining. The protein expression of NF-κB p65 in the myocardial nucleus was determined by the method of immunohistochemistry. The content of tumor necrosis factor α (TNF-α) in the myocardial tissues was detected by Western blotting. The level of interleukin 1β (IL-1β) in the serum was measured by ELISA. The activity of myeloperoxidase (MPO) in the myocardial tissues was assayed by colorimetry. RESULTS:Compared with sham group, TNF-α content, IL-1β concentration, NF-κB expression and MPO activity in all other groups increased. Compared with model group, TNF-α content, IL-1β concentration, NF-κB expression and MPO activity in low-, middle- and high-dose icariin groups and aspirin group all decreased. No significant difference of the above parameters between high-dose icariin group and aspirin group was observed. CONCLUSION: Icariin preconditioning reduces inflammatory responses in the process of myocardial ischemia-reperfusion injury in a dose-dependent manner.     

Hydrogen sulfide inhibits inflammatory responses induced by acute myocardial ischemia in isolated rat hearts

AIM：To investigate whether hydrogen sulfide (H2S) protects the hearts against inflammatory responses induced by acute myocardial ischemia in isolated rat hearts. METHODS：Rat acute myocardial ischemia injury was induced by ligation of the left anterior descending coronary artery for 4 h, and the normal perfusate was replaced with NaHS (5 μmol/L, 10 μmol/L and 20 μmol/L) perfusate accordingly in NaHS groups 2 h after ischemia. The changes of cardiac function in the myocardial ischemic injury rats were observed. The mRNA expression of TNF-α, IL-1β, IL-6, IL-10 and ICAM-1 was detected by real-time PCR. The protein level of nuclear factor-κB (NF-κB) in the myocardial tissues was detected by Western blotting. RESULTS：The cardiac function in ischemia group was lower than that in sham group (P<0.01). Compared with ischemia group, perfusion of NaHS resulted in the improvement of the cardiac function (P<0.05 or P<0.01). Compared with sham group, the mRNA expression of TNF-α, IL-1β, IL-6 and ICAM-1 in the cardiac tissues was significantly increased, and the mRNA expression of IL-10 in the cardiac tissues was significantly decreased in ischemia group (P<0.01). Compared with ischemia group, the perfusion of NaHS significantly decreased the mRNA expression of TNF-α, IL-1β, IL-6 and ICAM-1 (P<0.05 or P<0.01). The perfusion of NaHS at concentrations of 10 μmol/L and 20 μmol/L significantly increased the mRNA expression of IL-10 (P<0.01). The protein level of NF-κB in ischemia group was markedly higher than that in sham group (P<0.01). Compared with ischemia group, the perfusion of NaHS at concentrations of 10 μmol/L and 20 μmol/L significantly decreased the expression of NF-κB (P<0.05 or P<0.01). CONCLUSION：H2S protects the hearts against acute ischemia injury through inhibition of NF-κB activation and subsequent down-regulation of NF-κB-dependent inflammatory gene expression.     

Influence of ginsenoside Re on vascular intima hyperplasia and NF-κB p65 signaling pathway in balloon-injured rats

AIM: To investigate the inhibitory effect of ginsenoside Re on intimal hyperplasia induced by balloon-injury and to explore the role of NF-κB p65 signaling pathway in the process. METHODS: SD rats(n=40) were divided into 5 groups randomly: sham operation group, model group, low-dose ginsenoside Re group, middle-dose ginsenoside Re group and high-dose ginsenoside Re group. The carotid artery intima injury model was established by 2F balloon catheters in all groups except the sham operation group. The day after modeling, the animals in model group and sham operation group were administered intragastrically with distilled water, and the rats in low-dose, middle-dose and high-dose ginsenoside Re groups were given ginsenoside Re at doses of 12.5 mg/kg, 25mg/kg and 50 mg/kg, respectively. After 14 continuous days, the morphological changes of the injured arteries were observed by HE staining and the lumen area, intima area and media area as well as the ratio of intimal area/media area were determined. The expression of tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) were detected by real-time PCR. The proliferating cell nuclear antigen(PCNA) and nuclear factor-kappa B(NF-κB) p65 were examined by immunohistochemistry.RESULTS: Compared with sham operation group, the vessel cavity was narrowed(P<0.01), the mRNA levels of TNF-α and IL-1β, and the protein expression of PCNA and NF-κB p65 were increased in model group(P<0.05). Compared with model group, the vascular intimal hyperplasia was alleviated obviously(P<0.05), and the mRNA levels of TNF-α and IL-1β, and protein expression of PCNA and NF-κB p65 were decreased in medium and high-dose ginsenoside Re groups(P<0.05). CONCLUSION: Ginsenoside Re inhibits the vascular neointimal hyperplasia induced by balloon-injury in rats, and the molecular mechanism may be related to the inhibition of NF-κB p65 signaling pathway.     

The potential role of staphylococcal enterotoxin B in the early intestinal injury in postburn Staphylococcus aureus sepsis

AIM: To investigate the role of staphylococcal enterotoxin B (SEB) in early intestinal injury in scald rats with Staphylococcus aureus sepsis. METHODS: 86 male Wistar rats were randomly divided into four groups as folows: normal controls (n=10), scald control group(n=10), postburn sepsis group (n=50) and SEB monoclonal antibody (MAb) treatment group (n=16). Plasma samples were collected to determine SEB, endotoxin, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). RESULTS: After scald injury followed by Staphylococcus aureus challenge, the levels of SEB, TNF-α and IFN-γ in plasma were significantly higher than those of normal controls, peaking at 2-6 h (P<0.05 or P<0.01), while the intestinal diamine oxidase (DAO) activity declined constantly (P<0.05). It was shown that plasma SEB levels were significant negatively correlated with intestinal DAO activity (r=-0.4398, P=0.0170), and SEB MAb pretreatment could ameliorate the intestinal injury to certain extent. Moreover, Staphylococcus aureus challenge could increase the endotoxin levels in plasma and various tissues, which were attenuated by SEB MAb pretreatment. CONCLUSION: In postburn sepsis, SEB might be involved in the development of intestinal barrier dysfunction, which in turn resulting in gut-derived endotoxin translocation and aggravating the pathophysiologic changes caused by Staphylococcus aureus challenge.     

Ethanol extract from Cortex Albiziae attenuates mouse acute liver injury induced by carbon tetrachloride via modulation of NF-κB pathway

AIM:To investigate the protective effect of ethanol extract from Cortex Albiziae on acute liver injury, and to explore its possible mechanism. METHODS:Acute liver injury in mice was induced by single intraperitoneal injection of 25% carbon tetrachloride (olive oil solubilization). The effective parts of ethanol extract from Cortex Albizziae against acute liver injury were screened. The pathological changes of the liver tissues were examined by pathological sections with HE staining. The activity of total superoxide dismutase (T-SOD) and the content of malondialdehyde (MDA) of the liver tissues were detected, the serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were mea-sured by ELISA, and the protein expression levels of NF-κB p65, Bcl-2 and Bax in the liver cells of the mice in each group were determined by Western blot. RESULTS:Compared with model group, the serum levels of AST and ALT in low-dose n-butanol phase of ethanol extract from Cortex Albiziae (AB-L, 4 mg·kg^-1·d^-1) group and high-dose n-butanol phase of ethanol extract from Cortex Albiziae (AB-H, 8 mg·kg^-1·d^-1) group were significantly decreased. The necrosis extent and degree of the hepatocytes and infiltration of inflammatory cells were significantly lower than that in model group. Compared with model group, the serum levels of TNF-α and IL-6 in AB-H group and AB-L group were significantly decreased (P<0.05). The protein level of NF-κB p65 in the nuclei of mouse liver cells in AB-H group and AB-L group were also decreased significantly (P<0.05). Compared with model group, the protein expression of Bax was decreased, the protein expression of Bcl-2 was increased, and the Bcl-2/Bax ratio was increased in AB-L group and AB-H group. CONCLUSION:The n-butanol phase of ethanol extract from Cortex Albiziae may protect the liver by reducing the activation of NF-κB p65, inhibiting the excessive release of inflammatory cytokines IL-6 and TNF-α, and decreasing hepatocyte apoptosis via regulating Bcl-2 and Bax expression.     

Dexmedetomidine attenuates acute kidney injury induced by hemorrhagic shock/resuscitation in rats

AIM: To investigate the effects of dexmedetomidine on hemorrhagic shock/resuscitation (HS/R)-induced acute kidney injury (AKI) in rats, and to explore the possible mechanisms. METHODS: Wistar rats (n=32) were randomly divided into 4 groups (n=8):normal saline control group (NS group), dexmedetomidine group (D group), HS/R group and HS/R+D group. The animals were sacrificed at 6 h after resuscitation. The levels of serum creatinine (Cr) and blood urine nitrogen (BUN) were examined. The kidneys of all rats were removed for evaluation of histological characteristics, and the levels of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and superoxide dismutase (SOD) were measured. The expression of nuclear factor-κB (NF-κB) and hemeoxygenase-1 (HO-1) was determined by Western blot. RESULTS: Compared with NS group, the levels of Cr, BUN, MDA, TNF-α and IL-1β were obviously increased in HS/R group, which were obviously decreased in HS/R+D group (P<0.05). Compared with NS group, the SOD activity was obviously decreased in HS/R group, which was obviously increased in HS/R+D group (P<0.05). Compared with NS group, the protein expression of NF-κB was obviously increased in HS/R group, which was obviously decreased in HS/R+D group (P<0.05). Compared with NS group, the protein expression of HO-1 was increased in HS/R group. Compared with HS/R group, the protein expression of HO-1 was obviously increased in HS/R+D group. Compared with NS group, HS/R induced marked kidney histological injury, which was less pronounced in HS/R+D group.CONCLUSION: Dexmedetomidine effectively protects rats against AKI caused by HS/R, and its mechanism may be associated with the increase in HO-1 expression and the inhibition of NF-κB expression.     

Hypolipemic and hypoglycemic effects of total triterpenoids from Psidium guajava leaves on type 2 diabetic rats

AIM: To investigate the effects of total triterpenoids from Psidium guajava leaves (TTPGL) on blood glucose and lipids in type 2 diabetic rats. METHODS: The diabetic rats were induced by intraperitoneal injection of streptozotocin at dose of 35 mg/kg and feeding with high-fat diet. The animals were divided into 5 groups: diabetic model control group (model), TTPGL treatment groups (with the doses of 60, 120 and 240 mg/kg, respectively) and rosiglitazone treatment group (3 mg/kg). Another 12 normal SD rats were used as the normal controls. The rats received daily treatment for 6 weeks, and then the levels of fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG), total cholesterol (TCH), free fatty acid (FFA), glycosylated hemoglobin (GHb) and glycosylated serum proteins (GSP) were measured. The protein expression of peroxisome proliferator-activated receptor γ (PPARγ) in adipose tissues was detected by Western blotting. RESULTS: Compared with normal control group, the levels of FBG, GHb and blood lipids were increased in type 2 diabetic rats. The FINS, insulin sensitivity index, and the protein expression of PPARγ in adipose tissues were decreased. Compared with model group, the levels of FBG and GSP were decreased,and the FINS, insulin sensitivity index, and the protein expression of PPARγ in adipose tissues significantly increased in TTPGL treatment groups (with the doses of 120 and 240 mg/kg). The levels of serum TG,TCH and FFA were significantly lower in TTPGL treatment groups (P<0.01 or P<0.05) as compared with the model controls. CONCLUSION: TTPGL decreases the levels of blood glucose and lipids in diabetic rats. TTPGL also increases serum insulin level and improves insulin sensitivity. The action mechanism of TTPGL may be related to the increase in the protein expression of PPARγ.     

Expression and function of TNF-α in dorsal root ganglion of rats with chronically compressed dorsal root ganglion

AIM: To investigate the role of TNF-α and NF-κB in the mechanism of neuropathic pain due to chronically compressed dorsal root ganglion (CCD).METHODS: Based on the CCD model, von Frey filaments were used to quantify behavior test. The expression changes of TNF-α and NF-κB were determined by Western blotting, and the correlation between the expression of TNF-α and the 50% paw withdrawal threshold was also analyzed. Moreover, the location of TNF-α in dorsal root ganglion (DRG) was observed with immunofluorescence double staining.RESULTS: We found 50% paw withdrawal threshold of CCD decreased at the first day after operation. The mechanical allodynia was the most obvious at postoperative 7~14 d and lasted longer than 35 d. The expression of TNF-α and NF-κB increased significantly in DRG after operation (P<0.01), especially at 7~14 d, and then restored gradually. Moreover, there was a correlation between the protein expression of TNF-α and the changes of neuropathic behavior (P<0.05).CONCLUSION: TNF-α and NF-κB are involved in the mechanism of mechanical allodynia after chronically compressed DRG.     

Effects of Jiedu-Qingfei mixture on NF-κB and p38 MAPK pathways in lung tissues of rats with Mycoplasma pneumoniae infection

AIM: To observe the therapeutic effect of Jiedu-Qingfei mixture on Mycoplasma pneumoniae (MP)-infected rat lung tissues and to explore its mechanism. METHODS: SD rats (n=40) were randomly divided into 4 groups:blank control group, model group, Jiedu-Qingfei group and positive control group, with 10 rats in each group. The rats in experimental groups were slowly dripped with 1×10⁹ CFU/L MP solution into their nostrils for 4 d. One rat in each group was sacrificed for MP nucleic acid detection at the second day after inoculation, and the other rats were given gavage therapy. The rats in blank control group and model group were intragastrically given the same volume of normal saline, the rats in Jiedu-Qingfei group were given 8 mL/kg Jiedu-Qingfei mixture daily for 4 weeks, and the rats in psoitive control group were given dexmethasone sodium phosphate (0.5 mg·kg^-1·d^-1). After the experiment, the rats were killed. The serum and bronchoalveolar lavage fluid (BALF) were collected for detecting the levels of interleukin-12 (IL-12), IL-13 and TNF-α by ELISA. The right lung tissues were used for pathological observation and HE staining, while the left lung tissues were used to detect the expression of NF-κB p50, I-κBα and p38 mitogen-activated protein kinase (p38 MAPK) at mRNA and protein levels. RESULTS: The results of MP nucleic acid detection showed that all the rats except blank control group were MP nucleic acid positive, indicating that the rat model of MP infection was successfully established. On the 1st day of the treatment, the pathological scores of the lung tissues in model group and Jiedu-Qingfei group were significantly higher than those in blank control group (P<0.05). After treatment, the pathological scores of the lung tissues in mo-del group were significantly higher than those in blank control group and Jiedu-Qingfei group. The levels of IL-12 in the serum and BALF in model group were significantly lower than those in blank control group after MP infection (P<0.05), while those after treatment with Jiedu-Qingfei mixture were significantly higher than those in model group (P<0.05). The levels of IL-13 and TNF-α in the serum and BALF of MP-infected rats were increased significantly, while those after treatment with Jiedu-Qingfei mixture were significantly lower than those in model group (P<0.05). The mRNA expression levels of NF-κB p50 and p38 MAPK in model group were increased significantly (P<0.01). After treatment, the mRNA expression levels of NF-κB p50 and p38 MAPK were decreased significantly compared with model group (P<0.01). The mRNA expression level of I-κBα in model group was significantly lower than that in control group. After treatment, the mRNA expression of I-κBα in Jiedu-Qingfei group was significantly higher than that in model group (P<0.05). The protein levels of NF-κB p50 and p38 MAPK in the lung tissues of model group were significantly higher than those of blank control group. After treatment, the protein expression of NF-κB p50 and p38 MAPK was decreased significantly. The protein level of I-κBα in model group was significantly lower than that in blank control group, and after treatment with Jiedu-Qingfei mixture, the protein expression level of I-κBα was increased significantly (P<0.05). CONCLUSION: Jiedu-Qingfei mixture may attenuate lung tissue inflammation caused by MP through NF-κB and p38 MAPK pathways.     

Role of 78 kD glucose-regulated protein in the development of liver cirrhosis promoted by intestinal endotoxemia in rats

AIM: To explore the role of 78 kD glucose-regulated protein (GRP78) in the development of liver cirrhosis in rats promoted by intestinal endotoxemia (IETM). METHODS: Fifty-one male Wistar rats were randomly divided into liver cirrhosis groups of 4th-week, 6th-week and 8th-week, and normal control group at the corresponding time points. The rat model of hepatic cirrhosis was induced by employing multiple pathogenic factors to the animals. The liver injury and hepatic fibrosis were observed with the staining of HE and VG, respectively. The expression of GRP78 at the mRNA and protein levels was measured by the methods of RT-PCR and immnunohistochemistry, respectively. The concentrations of alanine aminotransferase(ALT), endotoxin, TNF-α and homocystine (HCY) in plasma, and the content of TNF-α, malondialdehyde(MDA) and PⅢP in liver tissues were detected. RESULTS: As liver cirrhosis developed, the levels of ALT, endotoxin, TNF-α and HCY in plasma, the expression of GRP78 at mRNA and protein, the content of TNF-α, MDA and PⅢP in liver tissues, and the index of liver fibrosis were gradually increased and were significantly higher than those in normal control group (P<0.05). Elevated endotoxin in plasma was correlated positively with the protein expression of GRP78, the content of MDA and HCY in plasma and the index of liver fibrosis (P<0.01). Elevated protein expression of GRP78 was correlated positively with the content of MDA and HCY in plasma and the index of liver fibrosis (P<0.01). CONCLUSION: GRP78 plays an important role in the development of liver cirrhosis. Endoplasmic reticulum stress is a possible mechanism in the development of liver cirrhosis promoted by IETM.