Ameliorative effects of bombesin and neurotensin on trinitrobenzene sulphonic acid-induced colitis, oxidative damage and apoptosis in rats

AIM： TO investigate the effects of bombesin （BBS） and neurotensin （NTS） on apoptosis and colitis in an ulcerative colitis model.
METHODS： In this study, a total of 50 rats were divided equally into 5 groups. In the control group, no colitis induction or drug administration was performed. Colitis was induced in all other groups. Following the induction of colitis, BBS, NTS or both were applied to three groups of rats. The remaining group （colitis group） received no treatment. On the 11th d after induction of colitis and drug treatment, blood samples were collected for TNF-α and IL-6 level studies. Malondialdehyde （MDA）, carbonyl, myeloperoxidase （MPO） and caspase-3 activities, as well as histopathological findings, evaluated in colonic tissues.
RESULTS： According to the macroscopic and microscopic findings, the study groups treated with BBS, NTS and BBS ＋ NTS showed significantly lower damage and inflammation compared with the colitis group （macroscopic score, 2.1 ± 0.87, 3.7 ± 0.94 and 2.1 ± 0.87 vs 7.3 ± 0.94; microscopic score, 2.0 ± 0.66, 3.3 ± 0.82 and 1.8 ± 0.63 vs 5.2 ± 0.78, P 〈 0.01）. TNF-α and IL-6 levels were increased significantly in all groups
compared with the control group. These increases were significantly smaller in the BBS, NTS and BBS ＋ NTS groups compared with the colitis group （TNF-α levels, 169.69 ± 53.56, 245.86 ± 64.85 and 175.54 ± 42.19 vs 556.44 ± 49.82; IL-6 levels, 443.30 ± 53.99, 612.80 ± 70.39 and 396.80 ± 78.43 vs 1505.90 ± 222.23, P 〈 0.05）. The colonic MPO and MDA levels were significantly lower in control, BBS, NTS and BBS ＋ NTS groups than in the colitis group （MPO levels, 24.36 ± 8.10, 40.51 ± 8.67 and 25.83 ± 6.43 vs 161.47 ± 38.24; MDA levels, 4.70 ± 1.41, 6.55 ± 1.12 and 4.51 ± 0.54 vs 15.60 ± 1.88, P 〈 0.05）. Carbonyl content and caspase-3 levels were higher in the colitis and NTS groups than in control, BBS and BBS ＋ NTS groups （carbonyl levels, 553.99 ± 59.58 and 336.26 ± 35.72 vs 209.7     

The role of endotoxin,TNF—α,and IL—6 in inducing the state of growth hormone insensitivity

AIM：Critical illnesses such as sepsis,trauma,and burns cause a growth hormone insensitivity,wehich leads to an increased negative nitrogen balance.Endotoxin is generously released into blood under these conditions and stimulates the production of proinflammatory cytokines such as TNF-α,IL-6,and IL-1 which may play a very important role in inducing the growth hormone insensitivity,The objective of this current study was to investigate the role of endotoxin,TNFα and IL-6 in inducing the growth hormone insensityvity at the receptor and post-receptor levels.METHODS:Spageu-Dawley rats were injected with endotoxin,TNF-α,and IL-6,respectively and part of rats injected with endotoxin was treated with exogenous somatotropin simultaneously,All rats were killed at different time points,The expression of IGF-I,GHR,SOCS-3 and β-actin mRNA in the liver was detected by RT-PCR and the GH levels were measured by radioimmunoassay,the levels of TNF-α and IL-6 were detected by ELISA.RESULTS:There was no significant difference in serous GH levels between experimental group and control rats after endotoxin injection,However,liver IGF-1 mRNA expression had been obviously down-regulated in endotoxeminc rats.Liver GHR mRNA expression also had a predominant downregulation after endotoxin injection,The lowest regulation of liver IGF-I mRNA expression occurred at 12h after LPS injection,being decreased by 53% compared with control rats.For GHR mRNA expression,the lowest expression occurred at 8h and had a 81% decrease.Although SOCS-3 mRNA was weakly expressed in control rats,it was strongly up-regulated after LPS injection and had a 7.84 times increase compared with control rats.Exogenous GH could enhance IGF-1 mRNA expression in control rats,but if did fail to prevent the decline in IGF-1 mRNA expression in endotoxemic rats,Endotoxin stimulated the production of TNF-α and IL-6,and the elevated IL-6 levels was shown a positive correlation with increased SOCS-3 mRNA expression.The liver GHR mRNA expression was obviously down-regulated after TNF-α iv injection and had a 40 decresase at 8 h,but the liver socs-3 mRNA expression was the 4.94 times up-regulation occurred at 40 min after IL-6 injection.CONCLUSION:The growth homone insenstivity could be induced by LPS injection,which was associated with down regulated GHR mRNA expression at receptor level and with up-regulated SOCS-3 mRNA expression at post-receptor level The in vivo biological activities of LPS were mediated by TNF-α and IL-6 indirectly,and TNF-αand IL-6 may exert their effects on.the receptor and post-receptor levels respectively.     

Hepatic fibrosis in biliary-obstructed rats is prevented by Ginkgo biloba treatment

AIM: To assess the antioxidant and antifibrotic effects of long-term Ginkgo biloba administration on liver fibrosis induced by biliary obstruction in rats. METHODS: Liver fibrosis was induced in male Wistar albino rats by bile duct ligation and scission (BDL). Ginkgo biloba extract (EGb 761, 50 mg/kg·per d) or saline was administered for 28 d. At the end of the treatment period, all rats were killed. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were determined to assess liver functions and tissue damage, respectively. Tumor necrosis factorα (TNF-α) was also assayed in serum samples. Liver tissues were taken for determination of the hepatic malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemiluminescence (CL) assay. Serum AST, ALT, LDH, and TNF-α levels were elevated in the BDL group as compared to control group and were significantly decreased by EGb treatment. RESULTS: Hepatic GSH level, depressed by BDL, was elevated back to control level in EGb-treated BDL group. Increase in tissue MDA level, MPO activity and collagen content due to BDL were also attenuated by EGb treatment. Furthermore, luminol and lucigenin CL values in BDL group increased dramatically compared to control and reduced by EGb treatment. CONCLUSION: Our results suggest that Ginkgo biloba protects the liver from oxidative damage following BDL in rats. This effect possibly involves the inhibition of neutrophil infiltration and lipid peroxidation; thus, restoration of oxidant and antioxidant status in the tissue.     

Preventive effect of hydrotalcite on gastric mucosal injury in rats induced by taurocholate

AIM: To study the preventive effect of hydrotalcite on gastric mucosal injury in rat induced by taurocholate, and to investigate the relationship between the protective mechanism of hydrotalcite and the expression of trefoil factor family 2 (TFF2) mRNA and c-fos protein.METHODS: Forty five male Wistar rats were randomly divided into hydrotalcite group, ranitidine group and control group. Gastric mucosal injury was induced by introgastric acidified taurocholate. OD value of TFF2 mRNA expression in gastric mucous cells was determined by hybridization and computer image analysis system. OD value of c-fos protein expression in gastric mucous cells was measured by immunohistochemistry and computer image analysis system.RESULTS: The gross mucosal injury index in hydrotalcite group was significantly lower than that in ranitidine group and control group (8.60±2.20 vs 16.32±4.27, 29.53±5.39;P＜0.05, P＜0.01). The expression level of TFF2 mRNA in hydrotalcite group was markedly higher than that in ranitidine group and control group (0.56±0.09 vs 0.30±0.05, 0.28±0.03,P＜0.05). The OD value of c-fos protein in hydrotalcite group was higher than that in ranitidine group and control group (0.52±0.07 vs 0.31±0.04, 0.32±0.05, P＜0.05).CONCLUSION: Hydrotalcite can protect gastric mucosal injury in rats induced by taurocholate, which may be related to the increased expression of TFF2 and c-fos protein.     

Expression and significance of nuclear factor κB p65 in colon tissues of rats with TNBS-induced colitis

AIM: To investigate the role of NF-κB in the pathogenesis of TNBS-induced colitis in rats. METHODS: Thirty-two healthy adult Sprague-Dawley (SD) rats were randomly divided into four groups of eight each: normal, NS, model Ⅰ, model Ⅱ groups in our study. Rat colitis model was established through 2-,4-,6-trinitrobenzene sulfonic acid (TNBS) enema. At the end of four weeks, the macroscopical and histological changes of the colon were examined and mucosa myeloperoxidase (MPO) activities assayed. NF-κB p65 expression was determined by Western blot assessment in cytoplasmic and nuclear extracts of colon tissue, and the expressions of TNF-α and ICAM-1 protein in colon tissue were examined by immunohistochemistry. The relativities between expression of NF-κB p65 and other parameters were analyzed. RESULTS: TNBS enema resulted in pronounced pathological changes of colonic mucosa in model Ⅱ group (macroscopic and histological injury indices 6.25±1.39 and 6.24±1.04, respectively), which were in accordance with the significantly elevated MPO activity (1.69±0.11). And the nuclear level of NF-κB and expression of TNF-α, ICAM-1 in rats of model II group were higher than that of normal control (9.7±1.96 vs1.7±0.15, 84.09±14.52 vs 16.03±6.21, 77.69±8.09 vs 13.41±4.91 P<0.01), Linear correlation analysis revealed that there were strong correlations between the nuclear level of NF-κB and the tissue positive expression of TNF-α and ICAM-1, MPO activities, macroscopical and histological indices in TNBS-induced colitis, respectively (r= 0.8235, 0.8780, 0.8572, 0.9152, 0.8247; P<0.05). CONCLUSION: NF-κB plays a pivotal role in the pathogenesis of ulcerative colitis, which might account for the up-regulation the expression of TNF-α and ICAM-1.     

Protective effect of angelica sinensis polysaccharide on experimental immunological colon injury in rats

AIM: To study the effect of angelica sinensis polysaccharide (ASP) on immunological colon injury and its mechanisms in rats.METHODS: Immunological colitis model of rats was induced by intracolon enema with 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) and ethanol. The experimental animals were randomly divided into normal control, model control, 5-aminosalicylic acid therapy groups and three doses of ASP therapy groups. The 6 groups were treated intracolonically with normal saline, normal saline, 5-aminosalicylic acid (100 mg.kg-1), and ASP daily (8:00 am) at the doses of 200, 400 and 800 mg.kg-1 respectively for 21 days 7 d following induction of colitis. The rat colon mucosa damage index (CMDI), the histopathological score (HS), the score of occult blood test (OBT), and the colonic MPO activity were evaluated. The levels of SOD, MDA, NO, TNF-α, IL-2 and IL-10 in colonic tissues were detected biochemically and immunoradiometrically. The expressions of TGF-β and EGF in colonic tissues were also determined immunochemically.RESULTS: Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in colitis rats,which manifested as significant increases of CMDI, HS, OBT,MPO activity, MDA and NO contents, as well as the levels of TNF-α and IL-2 in colonic tissues, although colonic TGF-β protein expression, SOD activity and TL-10 content were significantly decreased compared with the normal control (P＜0.01). However, these parameters were found to be significantly ameliorated in colitis rats treated intracolicly with ASP at the doses of 400 and 800 mg@kg-1 (P＜0.05-0.01).Meantime, colonic EGF protein expression in colitis rats was remarkably up-regulated.CONCLUSION: ASP has a protective effect on immunological colon injury induced by TNBS and ethanol enema in rats,which was propably due to the mechanism of antioxidation,immunomodulation and promotion of wound repair.     

Intravenous infusion of mesenteric lymph from severe intraperitoneal infection rats causes lung injury in healthy rats

AIM:To investigate whether mesenteric lymph from rats with severe intraperitoneal infection(SII)induces lung injury in healthy rats.METHODS:Twenty adult male specific pathogen-free Wistar rats were divided into two groups.Animals in the SII group received intraperitoneal injection of Escherichia coli(E.coli)at a dose of 0.3 mL/100 g.Control rats underwent the same procedure,but were injected with normal saline rather than E.coli.We ligated and drained the mesenteric lymphatic vessels and collected the mesenteric lymph.Mesenteric lymph collected from SII or control rats was infused intravenously into male healthy rats at a rate of 1 mL/h for 4 h.At the end of the infusion,all rats were sacrificed.Lungs were removed and examined histologically,and wet-to-dry weight(W/D)ratio and myeloperoxidase(MPO)activity were determined.Enzyme-linked immunosorbent assay(ELISA)was performed to determine the levels of the proinflammatory cytokines tumor necrosis factor(TNF)-αand interleukin(IL)-6.We performed Western blot to investigate the activation of Toll-like receptor(TLR)-4,and nuclear factor(NF)-κB p65.RESULTS:Compared with the control infusion group,there were obvious pathological changes in the SII group.The W/D ratio was significantly increased in the SII compared to control infusion group(5.86±0.06vs 5.37±0.06,P<0.01).MPO activity significantly increased in the SII infusion rats with a mean level of0.86±0.02 U/g compared to 0.18±0.05 U/g in the control group(P<0.01).The concentrations of TNF-αand IL-6 were significantly increased in the SII infusion group.The concentration of TNF-αwas significantly increased in the SII infusion rats compared to control infusion rats(2104.46±245.91 vs 1475.13±137.82pg/mL,P<0.01).The concentration of IL-6 was significantly increased in the SII infusion rats with a mean level of 50.56±2.85 pg/mL compared to 43.29±2.02 pg/mL(P<0.01).The expression levels of TLR-4(7496.68±376.43 vs 4589.02±233.16,P<0.01)and NF-κB(8722.19±323.96 vs 6498.91±338.76,P<0.01)were significantly increased in the SII infusion group compared to the control infusion group.The infusion of SII lymph,but not control lymph,caused lung injury.CONCLUSION:The results indicate that SII lymph is sufficient to induce acute lung injury.     

Preventative effects of a probiotic, Lactobacillus salivarius ssp. salivarius, in the TNBS model of rat colitis

AIM: To investigate the intestinal anti-inflammatory effect and mechanism of a probiotic Lactobacillus salivarius ssp. salivarius CECT5713 in the TNBS model of rat colitis. METHODS: Female Wistar rats (180-200 g) were used in this study. A group of rats were administered orally the probiotic L. salivarius ssp. salivarius(5×108 CFU suspended in 0.5 mL of skimmed milk) daily for 3 wk. Two additional groups were used for reference, a non-colitic and a control colitic without probiotic treatment, which received orally the vehicle used to administer the probiotic. Two weeks after starting the experiment, the rats were rendered colitic by intracolonic administration of 10 mg of TNBS dissolved in 0.25 mL of 500 mL/L ethanol. One week after colitis induction, all animals were killed and colonic damage was evaluated both histologically and biochemically. The biochemical studies performed in colonic homogenates include determination of myeloperoxidase (MPO) activity, glutathione (GSH) content, leukotriene B4 (LTB4) and tumor necrosis factor a (TNF-α) levels, as well as inducible nitric oxide synthase (iNOS) expression. In addition, the luminal contents obtained from colonic samples were used for microbiological studies, in order to determine Lactobacilli and Bifidobacteria counts. RESULTS: Treatment of colitic rats with L salivarius ssp. salivarius resulted in amelioration of the inflammatory response in colitic rats, when compared with the corresponding control group without probiotic treatment. This anti-inflammatory effect was evidenced macroscopically by a significant reduction in the extent of colonic necrosis and/or inflammation induced by the administration of TNBS/ethanol (2.3±0.4 cm vs 53.4±0.3 cm in control group, P<0.01) and histologically by improvement of the colonic architecture associated with a reduction in the neutrophil infiltrate in comparison with non-treated colitic rats. The latter was confirmed biochemically by a significant reduction of colonic MPO activity (105.3±26.0 U/g vs 180.6±21.9 U/g, P<0.05) a marker of neutrophil infiltration. The beneficial effect was associated with an increase of the colonic GSH content (1 252±42 nmol/g vs 1 087±51 nmol/g,P<0.05), which is depleted in colitic rats, as a consequence of the oxidative stress induced by the inflammatory process. In addition, the treatment of colitic rats with L. salivarius resulted in a significant reduction of colonic TNF-α levels (509.4±68.2 pg/g vs 782.9±60.1 pg/g, P<0.01) and in a lower colonic iNOS expression, when compared to TNBS control animals without probiotic administration. Finally, treated colitic rats showed higher counts of Lactobacilli species in colonic contents than control colitic rats, whereas no differences were observed in Bifidobacteria counts. CONCLUSION: Administration of the probiotic L. salivarius ssp. salivarius CECT5713 facilitates the recovery of the inflamed tissue in the TNBS model of rat colitis, an effect associated with amelioration of the production of some of the mediators involved in the inflammatory response in the intestine, such as cytokines, including TNF-α and NO. This beneficial effect could be ascribed to its effect on the altered immune response that occurs in this inflammatory condition.     

Electroacupuncture improves gut barrier dysfunction in prolonged hemorrhagic shock rats through vagus anti-inflammatory mechanism

AIM:To investigate whether electroacupuncture(EA)at Zusanli(ST36)prevents intestinal barrier and remote organ dysfunction following prolonged hemorrhagic shock through a vagus anti-inflammatory mechanism.METHODS:Sprague-Dawley rats were subjected to about 45%of total blood volume loss followed by delayed fluid replacement(DFR)with Ringer lactate 3h after hemorrhage.In a first study,rats were randomly divided into six groups:(1)EAN:EA at non-channel acupoints followed by DFR;(2)EA:EA at ST36 after hemorrhage followed by DFR;(3)VGX/EA:vagotomy(VGX)before EA at ST36 and DFR;(4)VGX/EAN:VGX before EAN and DFR;(5)α-bungarotoxin(α-BGT)/EA:intraperitoneal injection ofα-BGT before hemorrhage,followed by EA at ST36 and DFR;and(6)α-BGT/EAN group:α-BGT injection before hemorrhage followed by EAN and DFR.Survival and mean arterial pressure(MAP)were monitored over the next 12 h.In a second study,with the same grouping and treatment,cytokine levels in plasma and intestine,organ parameters,gut injury score,gut permeability to 4 kDa FITC-dextran,and expression and distribution of tight junction protein ZO-1 were evaluated.RESULTS:MAP was significantly lowered after blood loss;EA at ST36 improved the blood pressure at corresponding time points 3 and 12 h after hemorrhage.EA at ST36 reduced tumor necrosis factor-αand interleukin(IL)-6 levels in both plasma and intestine homogenates after blood loss and DFR,while vagotomy or intraperitoneal injection ofα-BGT before EA at ST36reversed its anti-inflammatory effects,and EA at ST36did not influence IL-10 levels in plasma and intestine.EA at ST36 alleviated the injury of intestinal villus,the gut injury score being significantly lower than that of EAN group(1.85±0.33 vs 3.78±0.59,P<0.05).EA at ST36 decreased intestinal permeability to FITCdextran compared with EAN group(856.95 ng/mL±90.65 ng/mL vs 2305.62 ng/mL±278.32 ng/mL,P<0.05).EA at ST36 significantly preserved ZO-1 protein expression and localization at 12 h after hemorrhage.However,EA at non-channel acupoints had     

Ameliorative effects of sodium ferulate on experimental colitis and their mechanisms in rats

AIM: To investigate the ameliorative effects of sodium ferulate (SF) on acetic acid-induced colitis and their mechanisms in rats.METHODS: The colitis model of Sprague-Dawley rats was induced by intracolon enema with 8 % (WV) of acetic acid.The experimental animals were randomly divided into model control, 5-aminosalicylic acid therapy group and three dose of SF therapy groups. The 5 groups were treated intracolonically and daily (8:00 am) for 7 days 24 h following the induction of colitis. A normal control group of rats clystered with normal saline instead of acetic acid was also included in the study.Pathological changes of the colonic mucosa were evaluated by the colon mucosa damage index (CMDI) and the histopathological score (HS). The insulted colonic mucosa was sampled for a variety of determinations at the end of experiment when the animals were sacrificed by decapitation.Colonic activities of myeloperoxidase (MPO) and superoxide dismutase (SOD), and levels of malondialdehyde (MDA)and nitric oxide (NO) were assayed with ultraviolet spectrophotometry. Colonic contents of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2)were determined by radioimmunoassay. The expressions of inducible nitric oxide synthase (iNOS), cyclo-oxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB) p65 proteins in the colonic tissue were detected with immunohistochemistry.RESULTS: Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in the animals clystered with acetic acid, which manifested as the significant increase of CMDI, HS, MPO activities, MDA and NO levels,PGE2 and TXB2 contents, as well as the expressions of iNOS,COX-2 and NF-κB p65 proteins in the colonic mucosa,although the colonic SOD activity was significantly decreased compared with the normal control (CMDI: 2.9±0.6 vs0.0±0.0;HS: 4.3±0.9 vs0.7±1.1; MPO: 98.1±26.9 vs24.8±11.5; MDA:57.53±12.36 vs9.21±3.85; NO: 0.331±0.092 vs0.176±0.045;PGE2: 186.2±96.2 vs 42.8±32.8; TXB2: 34.26±13.51 vs 8.83±3.75; iNOS: 0.365±0.026 vs0.053±0.015; COX-2:0.296±0.028 vs0.034±0.013; NF-κB p65:0.314±0.026 vs 0.039±0.012; SOD: 28.33±1.17 vs36.14±1.91; P<0.01).However, these parameters were found to be significantly ameliorated in rats treated locally with SF at the given dose (CMDI: 1.8±0.8, 1.6±0.9; HS: 3.3±0.9, 3.1±1.0; MPO:63.8±30.5, 36.2±14.2; MDA: 41.84±10.62, 37.34±8.58; NO:0.247±0.042; 0.216±0.033; PGE2: 77.2±26.9, 58.4±23.9;TXB2:18.07±14.83; 15.52±8.62; iNOS:0.175±0.018, 0.106±0.019;COX-2: 0.064±0.018, 0.056±0.014; NF-κBp65: 0.215±0.019,0.189±0.016; SOD: 32.15±4.26, 33.24±3.69; P<0.05-0.01).amelioration of colonic mucosal injury as evaluated by CMDI and HS.CONCLUSION: Administration of SF intracolonically may have significant therapeutic effects on the rat model of colitis induced by acetic acid enema, which was probably due to the mechanism of antioxidation, inhibition of arachidonic acid metabolism and NF-κB expression.     

Effect of endogenous insulin-like growth factor and stem cell factor on diabetic colonic dysmotility

AIM: To investigate whether the reduction of stem cell factor (SCF) is mediated by decreased endogenous insulin-like growth factor (IGF)-1 in diabetic rat colon smooth muscle. METHODS: Sixteen Sprague-Dawley rats were randomly divided into two groups: control group and streptozotocin-induced diabetic group. After 8 wk of streptozotocin administration, colonic motility function and contractility of circular muscle strips were measured. The expression of endogenous IGF-1 and SCF was tested in colonic tissues. Colonic smooth muscle cells were cultured from normal adult rats. IGF-1 siRNA transfection was used to investigate whether SCF expression was affected by endogenous IGF-1 expression in smooth muscle cells, and IGF-1 induced SCF expression effects were studied. The effect of high glucose on the expression of endogenous IGF-1 and SCF was also investigated. RESULTS: Diabetic rats showed prolonged colonic transit time (252 ± 16 min vs 168 ± 9 min, P < 0.01) and weakness of circular muscle contraction (0.81 ± 0.09 g vs 2.48 ± 0.23 g, P < 0.01) compared with the control group. Endogenous IGF-1 and SCF protein expression was significantly reduced in the diabetic colonic muscle tissues. IGF-1 and SCF mRNA expression also showed a paralleled reduction in diabetic rats. In the IGF-1 siRNA transfected smooth muscle cells, SCF mRNA and protein expression was significantly decreased. IGF-1 could induce SCF expression in a concentration and time-dependent manner, mainly through the extracellular-signal-regulated kinase 1/2 signal pathway. High glucose inhibited endogenous IGF-1 and SCF expression and the addition of IGF-1 to the medium reversed the SCF expression. CONCLUSION: Myopathy may resolve in colonic motility dysfunction in diabetic rats. Deficiency of endogenous IGF-1 in colonic smooth muscle cells leads to reduction of SCF expression.     

Expression and significance of nuclear factor κB p65 in colon tissues of rats with TNBS-induced colitis

AIM: To investigate the role of NF-κB in the pathogenesis of TNBS-induced colitis in rats. METHODS: Thirty-two healthy adult Sprague-Dawley (SD) rats were randomly divided into four groups of eight each: normal, NS, model Ⅰ, model Ⅱ groups in our study. Rat colitis model was established through 2-,4-,6-trinitrobenzene sulfonic acid (TNBS) enema. At the end of four weeks, the macroscopical and histological changes of the colon were examined and mucosa myeloperoxidase (MPO)activities assayed. NF-~B p65 expression was determined by Western blot assessment in cytoplasmic and nuclear extracts of colon tissue, and the expressions of TNF-α (and ICAM-1 protein in colon tissue were examined by immunohistochemistry. The relativities between expression of NF-κB p65 and other parameters were analyzed. RESULTS: TNBS enema resulted in pronounced pathological changes of colonic mucosa in model Ⅱ group (macroscopic and histological injury indices 6.25&#177;1.39 and 6.24&#177;1.04, respectively), which were in accordance with the significantly elevated MPO activity (1.69+0.11). And the nuclear level of NF-κB and expression of TNF-α, ICAM-1 in rats of model Ⅱ group were higher than that of normal control(9.7&#177;1.96 vs 1.7&#177;0.15, 84.09&#177;14.52 vs 16.03&#177;6.21,77.69&#177;8.09 vs 13.41&#177;4.91 P&lt;0.01), Linear correlation analysis revealed that there were strong correlations between the nuclear level of NF-κB and the tissue positive expression of TNF-α and ICAM-1, MPO activities, macroscopical and histological indices in TNBS-induced colitis, respectively (r = 0.8235, 0.8780, 0.8572, 0.9152,0.8247; P&lt;0.05). CONCLUSION: NF-κB plays a pivotal role in the pathogenesis of ulcerative colitis, which might account for the up-regulation the expression of TNF-α and ICAM-1.     

Anti-inflammatory mechanism of oxymatrine in dextran sulfate sodium-induced colitis of rats

AIM: To investigate the anti-inflammatory mechanism of oxymatrine in dextran sulfate sodium (DSS)-induced colitis of rats. METHODS: Acute colitis was induced by giving 2% DSS orally in drinking water for 8 d. Twenty-six male rats were randomized into oxymatrine-treated group (group A, 10 rats), DSS control (group B, 10 rats) and normal control (group C, 6 rats). The rats in group A were injected muscularly with oxymatrine at the dosage of 63 mg/(kg·d) from d 1 to 11 and drank 2% DSS solution from d 4 to 11. The rats in group B were treated with 0.9% saline in an equal volume as group A and drank 2% DSS solution from d 4 to 11. The rats in group C were treated with 0.9% saline as group B from d 1 to 11 and drank water normally. Diarrhea and bloody stool as well as colonic histology were observed. The levels of serum tumor necrosis factor-α(TNF-α) and interleukin-6 (IL-6) were determined by ELISA, and nuclear factor-κB (NF-κB) activity and the expression of inter-cellular adhesion molecule-1(ICAM-1) in colonic mucosa were detected by immunohistochemistry method. RESULTS: Compared with DSS contror group, the inflammatory symptoms and histological damages of colonic mucosa in oxymatrine-treated group were significantly improved, the serum levels of TNF-α, IL-6, and the expression of NF-κB, ICAM-1 in colonic mucosa were significantly reduced. CONCLUSION: The fact that oxymatrine can reduce the serum levels of TNF-α, IL-6, and the expression of NF-κB and ICAM-1 in colonic mucosa in DSS-induced colitis of rats indicates that oxymatrine may ameliorate the colonic inflammation and thus alleviate diarrhea and bloody stool.     

Electroacupuncture at ST36 modulates gastric motility via vagovagal and sympathetic reflexes in rats

BACKGROUND Electroacupuncture(EA) at ST36 can significantly improve gastrointestinal symptoms, especially in promoting gastrointestinal motility. The automatic nervous system plays a main role in EA, but few studies exist on how vagovagal and sympathetic reflexes affect EA to regulate gastrointestinal motility.AIM To study the role of vagovagal and sympathetic reflexes in EA at ST36, as well as the associated receptor subtypes that are involved.METHODS Gastric motility was measured with a manometric balloon placed in the gastric antrum area in anesthetized animals. The peripheral nervous discharge was measured using a platinum electrode hooking the vagus or greater splanchnic nerve, and the central nervous discharge was measured with a glass microelectrode in the dorsal motor nucleus of the vagus(DMV). The effects and mechanisms of EA at ST36 were explored in male Sprague-Dawley rats which were divided in to a control group, vagotomy group, sympathectomy group, and microinjection group [including an artificial cerebrospinal fluid group, glutamate(L-Glu) group, and γ-aminobutyric acid(GABA) group] and in genetically modified male mice [β1β2 receptor-knockout(β1β2^-/-) mice, M2M3 receptorknockout(M2M3^-/-) mice, and wild-type control mice].RESULTS EA at ST36 promoted gastric motility during 30-120 s. During EA, both vagus and sympathetic nerve discharges increased, with a much higher frequency of vagus nerve discharge than sympathetic discharge. The gastric motility mediated by EA at ST36 was interdicted by vagotomy. However, gastric motility mediated by EA at ST36 was increased during 0-120 s by sympathectomy, which eliminated the delay effect of EA during 0-30 s, but it was lower than the control group during 30-120 s. Using gene knockout mice and their wild-type controls to explore the receptor mechanisms, we found that EA at ST36 decreased gastric motility in M2/3^-/- mice, and promoted gastric motility in β1/2^-/- mice. Extracellular recordings showed that EA at ST36 increased spikes of the DMV. Microinjection of L-Glu into the DMV increased gastric motility, while EA at ST36 decreased gastric motility during 0-60 s, and promoted gastric motility during 60-120 s.Injection of GABA reduced or increased gastric motility, and reduced the promoting gastric motility effect of EA at ST36.CONCLUSION These data suggest that EA at ST36 modulates gastric motility via vagovagal and sympathetic reflexes mediated through M2/3 and β1/2 receptors, respectively.Sympathetic nerve activity mediated through β1/2 receptors is associated with an early delay in modulation of gastric motility by EA at ST36.     

Inhibitive effect of cordyceps sinensis on experimental hepatic fibrosis and its possible mechanism

AIM: To investigate the inhibitive effect and its possible mechanism of Cordyceps Sinensis (CS) on CCl4-plus ethanolinduced hepatic fibrogenesis in experimental rats.METHODS: Rats were randomly allocated into a normal control group, a model control group and a CS group. The latter two groups were administered with CCl4 and ethanol solution at the beginning of the experiment to induce hepatic fibrosis. The CS group was also treated with CS 10 days after the beginning of CCl4 and ethanol administration. All control groups were given corresponding placebo at the same time. At the end of the 9th week, rats in each group were humanely sacrificed. Blood and tissue specimens were taken.Biochemical, radioimmunological, immunohistochemical and molecular biological examinations were used to determine the level change of ALT, AST, HA, LN content in serum and TGFβ1, PDGF, collagen Ⅰ and Ⅲ expression in tissue at either protein or mRNA level or both of them.RESULTS: As compared with the model control group,serum ALr, AST, HA, and LN content levels were markedly dropped in CS group (86.0±34.4 vs224.3±178.9, 146.7±60.2vs272.6±130.1, 202.0±79.3 vs316.5±94.1 and 50.4±3.0vs 59.7±9.8, respectively, P＜0.05). Tissue expression of TGFβ1 and its mRNA, collagen I mRNA were also markedly decreased (0.2±0.14 vs1.73±1.40, 1.68±0.47 vs3.17±1.17,1.10±0.84 vs 2.64±1.40, respectively, P＜0.05). More dramatical drop could be seen in PDGF expression (0.87±0.43vs1.91±0.74, P＜0.01). Although there was no statistical significance, it was still strongly suggested that collagen Ⅲ mRNA expression was also decreased in CS group as compared with model control group (0.36±0.27 vs0.95±0.65,P=0.0615). In this experiment, no significant change could be found in PDGF mRNA expression between two groups (0.35±0.34 vs 0.70±0.46, P＞0.05).CONCLUSION: Cordyceps sinensis could inhibit hepatic fibrogenesis derived from chronic liver injury, retard the development of cirrhosis, and notably ameliorate the liver function. Its possible mechanism involves inhibiting TGFβ1expression, and thereby, down regulating PDGF expression,preventing HSC activation and deposition of procollagen Ⅰand Ⅲ.