Protective effect of simvastatin and rosuvastatin on trinitrobenzene sulfonic acid-induced colitis in rats

Objective:Statins have anti-inflammatory effects that are not directly related to their cholesterol lowering activity. This study was carried out to evaluate the effect of simvastatin or rosuvastatin on the extent of colonic mucosal damage and on the inflammatory response in trinitrobenzene sulfonic acid (TNBS)-induced ulcerative colitis.Result:Disease activity index score in TNBS-treated rats, as determined by weight loss, stool consistency, fecal occult blood, were significantly lowers in simvastatin or rosuvastatin-treated rats than TNBS-treated animals. Simvastatin or rosuvastatin counteracted the reduction in colon length, decreased colon weight, neutrophil accumulation, and tumor necrosis factor-alpha level in TNBS-induced colitis. Simvastatin and rosuvastatin also inhibited the increase in oxidative stress levels after TNBS administration.Conclusions:These results suggest that simvastatin and rosuvastatin significantly ameliorate experimental colitis in rats, and these effects could be explained by their anti-inflammatory and antioxidant activity.KEY WORDS: Rosuvastatin, simvastatin, trinitrobenzene sulfonic acid, tumor necrosis factor-α, ulcerative colitis     

Activation of nuclear factor-kappa B pathway by simvastatin and RhoA silencing increases doxorubicin cytotoxicity in human colon cancer HT29 cells

Doxorubicin efficacy in cancer therapy is hampered by the dose-dependent side effects, which may be overcome by reducing the drug's dose and increasing its efficacy. In the present work, we suggest that the activation of the nuclear factor-kappaB (NF-kappaB) pathway and of nitric-oxide (NO) synthase increases the doxorubicin efficacy in human colon cancer HT29 cells. To induce NF-kappaB, we took into account the effect of doxorubicin itself and of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor simvastatin; as NF-kappaB inhibitors, we chose the sesquiterpene lactones parthenolide and artemisinin. Simvastatin increased the NF-kappaB activity and NO synthesis, elicited the tyrosine nitration of the multidrug resistance-related protein 3, and enhanced the doxorubicin intracellular accumulation and cytotoxicity. Simvastatin potentiated the effect of doxorubicin on the NF-kappaB pathway and the inducible NO synthase expression. The effects of simvastatin were due to the inhibition of the small G-protein RhoA and of its effector Rho kinase. Parthenolide and artemisinin prevented all of the statin effects by inducing RhoA/Rho kinase activation. On the other hand, they did not reduce the NF-kappaB translocation and doxorubicin intracellular content when RhoA was silenced by small interfering RNA (siRNA). It is interesting that RhoA siRNA was sufficient to increase NF-kappaB translocation, NO synthase activity, doxorubicin accumulation, and cytotoxicity also in non-stimulated cells. Our results suggest that artemisinin, a widely used antimalarial drug, may impair the response to doxorubicin in colon cancer cells; on the contrary, simvastatin and RhoA siRNA may represent future therapeutic approaches to improve doxorubicin efficacy, reducing the risk of doxorubicin-dependent adverse effects.     

辛伐他汀抑制大鼠炎症性肠病结肠纤维化结缔组织生长因子的表达

目的探讨大鼠炎症性肠病(IBD)结肠纤维化结缔组织生长因子(CTGF)的表达及辛伐他汀对其影响。方法 32只SD大鼠均分为对照组、IBD模型对照组、辛伐他汀低剂量(5mg/kg)和高剂量(20mg/kg)干预组。21d后观察结肠病理组织学变化;RT-PCR和Western blot检测结肠Ⅰ型胶原、CTGF mRNA和蛋白表达。结果与对照组相比,模型组结肠黏膜及黏膜下层见大量炎症细胞浸润,纤维组织增生,Ⅰ型胶原和CTGF表达增多(P<0.01)。辛伐他汀干预后,病理组织学较模型组改善,Ⅰ型胶原和CTGF表达明显下降(P<0.05)。结论 CTGF参与结肠炎大鼠肠纤维化形成,辛伐他汀可能通过抑制CTGF的表达减轻IBD肠纤维化进展。     

2',4',6'-tris(methoxymethoxy) chalcone protects against trinitrobenzene sulfonic acid-induced colitis and blocks tumor necrosis factor-alpha-induced intestinal epithelial inflammation via heme oxygenase 1-dependent and independent pathways

2',4',6'-Tris(methoxymethoxy) chalcone (TMMC), a synthesized chalcone derivative, displays potent antiproliferative and anti-inflammatory effects in rat hepatic stellate cells and murine macrophages, respectively. Here we tested the hypothesis that TMMC could ameliorate diseases characterized by mucosal inflammation. Treatment of mice with TMMC significantly protected against trinitrobenzene sulfonic acid (TNBS)-induced colitis, as assessed by reductions in the weight loss, colonic damage and mucosal ulceration that together characterize this symptom. Moreover, TMMC suppressed the expression of intercellular adhesion molecule-1, interleukin 1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) in the mice treated with TNBS. Pretreatment of human intestinal epithelial HT-29 cells with TMMC also significantly inhibited the IL-8 and extracellular matrix metalloproteinase-7 levels induced by TNF-alpha. TMMC induced the expression of heme oxygenase 1 (HO-1) in HT-29 cells. TMMC increased extracellular signal-regulated kinase1/2 and p38 kinase phosphorylation levels, which led to the nuclear translocation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and consequently to HO-1 expression. TMMC inhibited TNF-alpha-induced nuclear factor kappaB (NF-kappaB) activation directly and indirectly. Interestingly, the latter is mediated by HO-1, which presumably blocks the TNF-alpha-induced nuclear translocation of NF-kappaB p65 without affecting I-kappaBalpha degradation. Moreover, we found that the different products of HO-1, carbon monoxide and bilirubin, exerted anti-inflammatory effects that were additive or synergistic in HT-29 cells stimulated with TNF-alpha. Thus, TMMC might serve to protect against intestinal inflammatory diseases.     

The intestinal anti-inflammatory effect of minocycline in experimental colitis involves both its immunomodulatory and antimicrobial properties

Some antibiotics, including minocycline, have recently been reported to display immunomodulatory properties in addition to their antimicrobial activity. The use of a compound with both immunomodulatory and antibacterial properties could be very interesting in the treatment of inflammatory bowel disease (IBD), so the aim of our study was to evaluate the anti-inflammatory effect of minocycline in several experimental models of IBD. Firstly, the immunomodulatory activity of the antibiotic was tested in vitro using Caco-2 intestinal epithelial cells and RAW 264.7 macrophages; minocycline was able to inhibit IL-8 and nitrite production, respectively. In vivo studies were performed in trinitrobenzenesulfonic acid (TNBS)-induced rat colitis and dextran sodium sulfate (DSS)-induced mouse colitis. The results revealed that minocycline exerted an intestinal anti-inflammatory effect when administered as a curative treatment in the TNBS model, modulating both immune and microbiological parameters, being confirmed in the DSS model; whereas none of the other antibiotics tested (tetracycline and metronidazole) showed anti-inflammatory effect. However, minocycline administration before the colitis induction was not able to prevent the development of the intestinal inflammation, thus showing that only its antimicrobial activity is not enough for the anti-inflammatory effect. In conclusion, minocycline displays an anti-inflammatory effect on different models of rodent colitis which could be attributed to the association of its antibacterial and immunomodulatory properties.     

Reversal of chemoresistance and enhancement of apoptosis by statins through down-regulation of the NF-kappaB pathway

We recently found that simvastatin can modulate the nuclear factor-kappaB (NF-kappaB) activation pathway, but whether other statins have similar effects to those of simvastatin is unknown. Therefore, we evaluated the effect six different statins on TNF-induced NF-kappaB activation in human myeloid leukemia cells. We then determined whether the combination of statins and standard chemotherapeutic agents could overcome chemoresistance and augment apoptosis. Of the six statins evaluated, only the natural statins (simvastatin, mevastatin, lovastatin, and pravastatin), not the synthetic statins (fluvastatin and atorvastatin), inhibited TNF-induced NF-kappaB activation. Simvastatin suppressed the NF-kappaB activation and potentiated the apoptosis induced by doxorubicin, paclitaxel, and 5-fluorouracil. These results suggest that different statins behave differently from one another and that they may be useful in overcoming chemoresistance.     

Lycopene inhibits TNF-alpha-induced endothelial ICAM-1 expression and monocyte-endothelial adhesion

Inflammatory mediators such as TNF-alpha and interleukin (IL)-1beta, and IL-8, which can enhance binding of low-density lipoprotein (LDL) to endothelium and upregulate expression of leukocyte adhesion molecules on endothelium during atherogenesis. Lycopene, a natural carotenoid from tomato and other sources, has been shown to prevent cardiovascular diseases in epidemiological studies. However, its anti-inflammatory action mechanism remains unclear. In the present study, we studied the effect of lycopene on TNF-alpha-induced signaling in human umbilical endothelial cells (HUVECs). We found that TNF-alpha-induced intercellular adhesion molecule-1 (ICAM-1) expression in HUVECs was inhibited by lycopene, whereas cyclooxygenase-2 (COX-2) and platelet-endothelial cell adhesion molecule (PECAM-1) expression were not affected. A further analysis indicated that lycopene attenuated TNF-alpha-induced IkappaB phosphorylation, NF-kappaB expression, and NF-kappaB p65 translocation from cytosol to nucleus. In line with this, TNF-alpha-induced NF-kappaB-DNA but not AP1-DNA complexes formation was inhibited by lycopene, as determined by the electrophoretic mobility shift assay (EMSA). On the other hand, lycopene did not affect TNF-alpha-induced p38 and extracellular matrix-regulated kinase1/2 (ERK1/2) phosphorylation and interferon-gamma (IFN-gamma)-induced signaling, suggesting that lycopene primarily affects TNF-alpha-induced NF-kappaB signaling pathway. In a functional study, lycopene dose-dependently attenuated monocyte adhesion to endothelial monolayer but not that adhesion to extracellular matrix. Taken together, we provided here the first evidence showing that lycopene is able to inhibit TNF-alpha-induced NF-kappaB activation, ICAM-1 expression, and monocyte-endothelial interaction, suggesting an anti-inflammatory role of lycopene and possibly explaining in part why lycopene can prevent cardiovascular diseases.     

Arginine or citrulline associated with a statin stimulates nitric oxide production in bovine aortic endothelial cells

Nitric oxide (NO) is an antiatherogenic vasodilator synthesized from arginine and, indirectly, from citrulline through argininosuccinate synthase (ASS) and argininosuccinate lyase (ASL). Hypercholesterolemia-induced atherosclerosis is usually treated by statins, which decrease cholesterolemia and increase endothelial NO synthase (eNOS) activity. Therefore, a treatment associating a statin with arginine or citrulline could be more efficient than statin alone. The aim of this study was to optimize NO production in bovine aortic endothelial cells (BAEC) by a combination of simvastatin with arginine or citrulline and to identify the molecular mechanisms involved. NO production was measured after stimulation of BAEC in different conditions (simvastatin 0 to 10 μM associated with arginine or citrulline 0 to 5 mM) after 24-hour incubation. Intracellular levels of specific proteins were evaluated by Western-Blot analysis, and mRNA levels of eNOS, iNOS, caveolin-1, ASS and ASL were assessed by RT-PCR. Simvastatin co-administrated with arginine or citrulline increased NO production, but at simvastatin 10 μM, 1 mM arginine-induced NO production was significantly (P < 0.01) higher than 1 mM citrulline-induced NO production. Simvastatin induced an increase in eNOS mRNA expression and protein levels in the presence of arginine or citrulline. ASS and ASL mRNA levels were increased by simvastatin, whereas a high substrate concentration (1 mM) strongly decreased ASL mRNA levels. Combining statin with arginine or citrulline increased NO production in endothelial cells by increasing eNOS protein levels. These results form a strong rationale to evaluate the potential utilization of these in atherosclerosis prevention and treatment.     

Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors,are able to reduce superoxide anion production by NADPH oxidase in THP-1-derived monocytes

Reactive oxygen species formation by phagocytes and subsequent modifications of vascular wall are involved in the early step of human atherogenesis. This study looked for the effect of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors on NADPH oxidase-dependent superoxide anion production in THP-1 cells, a monocyte-derived cell line, and on the translocation of p21 Rac 2 and p67. A 30-min incubation with simvastatin (50 micro M ) inhibited phorbol 12-myristate 13-acetate-induced superoxide anion production by monocytes (32%) and a maximum inhibition was obtained at 3 h of incubation (69.5%). In addition, after 3 h of incubation a dose-dependent inhibition was obtained in the range 10-50 micro M of simvastatin with a median inhibitory concentration of 36 +/- 2.3 micro M Mevalonic acid (100 and 300 micro M ) and geranylgeraniol (100 micro M ) totally prevented the simvastatin-induced inhibitory effect of superoxide production by monocytes whereas farnesyl PP (100 micro M ) partially prevented (50%) this effect. In addition, simvastatin inhibited the translocation of p21 rac 2 and p67, suggesting that geranylgeranylation is required for NADPH oxidase activation. In another set of experiments, the rank order of potency of different statins on NADPH oxidase was determined (pravastatin < cerivastatin < lovastatin < fluvastatin < simvastatin). In conclusion, inhibition of superoxide formation by HMG CoA reductase inhibitors is highly suitable to prevent or limit the oxidative stress involved in the atherosclerosis process.     

Lactoferrin-mediated macrophage targeting delivery and patchouli alcohol-based therapeutic strategy for inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are the incurable chronic recurrent gastrointestinal disorders and currently lack in safe and effective drugs. In this study, patchouli alcohol, a main active compound of traditional Chinese herb patchouli, was developed into biomimetic liposomes for macrophage-targeting delivery for IBD treatment. The developed lactoferrin-modified liposomes (LF-lipo) can specifically bind to LRP-1 expressed on the activated colonic macrophages and achieve cell-targeting anti-inflammatory therapy. LF-lipo reduced the levels of inflammatory cytokines and ROS and suppressed the MAPK/NF-κB pathway. LF-lipo also suppressed the formation of NLRP3 inflammasome and the consequent IL-1β activation. LF-lipo showed improved therapeutic efficacy in a DSS-induced colitis murine model, evidenced by the reduced disease activity index, the improved colon functions, and the downregulated inflammatory cytokines in the colon. LF-lipo provided an effective and safe macrophage-targeting delivery and therapeutic strategy for addressing the unmet medical need in IBD management.     

Immunomodulatory effects of M2000 (β-D-Mannuronic acid) on TNF-α, IL-17 and FOXP3 gene expression in patients with inflammatory bowel disease

IntroductionInflammatory bowel diseases (IBD) are immune-mediated disorders that result from an aberrant immunological response to the gut luminal antigen in genetically susceptible patients. IBD is categorized into two serotype, Crohn's diseases (CD) and ulcerative colitis (UC), both subtype are important cause of gastrointestinal diseases. The increasing rate of hospitalization, with the high economic burden experienced by the IBD patients, calls for more concerted research efforts to design a potent and affordable treatment option for the treatment of IBD.Aims/objectiveThis research was designed to test the efficacy and potency of β-D Mannuronic acid (M2000) and assess if it could serve as a better therapeutic option in the treatment of IBD.MethodologyTen (10)ml of blood was aseptically collected into an EDTA container, from 24 IBD patients and 24 normal healthy controls. PBMC was isolated and stimulated with 1 μg/ml of LPS in cell culture plate and incubated for 4 h. The cells were later treated with 10 μg/ml and 50 μg/ml of β-D Mannuronic acid (M2000) and incubated for 24 h at 37 °C under 5% CO2 and 100% humidity. The RNA extractions, cDNA synthesis, and QRT-PCR were performed.ResultsOur findings showed a significant down-regulation of TNF-α and IL-17 gene expression, while the expression of FOXP3 gene was significantly up-regulated.ConclusionThis result has indicated that β-D Mannuronic acid (M2000) have immunoregulatory and anti-inflammatory effects on these cytokines that are pivotal in the pathogenesis of IBD.     

Budesonide-loaded nanostructured lipid carriers reduce inflammation in murine DSS-induced colitis

The challenge for the treatment of inflammatory bowel disease (IBD) is the delivery of the drug to the site of inflammation. Because nanoparticles have the ability to accumulate in inflamed regions, the aim of the present study was to evaluate nanostructured lipid carriers (NLCs) as nanoparticulate drug delivery systems for the treatment of IBD. Budesonide (BDS) was chosen as a candidate anti-inflammatory drug. BDS-loaded NLCs (BDS-NLC) produced by high-pressure homogenization had a size of 200 nm and a negative zeta potential. BDS-NLCs reduced the TNF-α secretion by activated macrophages (J774 cells). BDS-NLCs were more active in a murine model of dextran sulfate-induced colitis when compared with Blank-NLCs or a BDS suspension: BDS-NLCs decreased neutrophil infiltration, decreased the levels of the pro-inflammatory cytokines IL-1β and TNF-α in the colon and improved the histological scores of the colons. These data suggest that NLCs could be a promising alternative to polymeric nanoparticles as a targeted drug delivery system for IBD treatment.     

Suppression of RelA/p65 transactivation activity by a lignoid manassantin isolated from Saururus chinensis

In our search for NF-kappaB inhibitors from natural resources, we have previously identified two structurally related dilignans, manassantin A and B as specific inhibitors of NF-kappaB activation from Saururus chinensis. However, their molecular mechanism of action remains unclear. We here demonstrate that manassantins A and B are potent inhibitors of NF-kappaB activation by the suppression of transciptional activity of RelA/p65 subunit of NF-kappaB. These compounds significantly inhibited the induced expression of NF-kappaB reporter gene by LPS or TNF-alpha in a dose-dependent manner. However, these compounds did not prevent the DNA-binding activity of NF-kappaB assessed by electrophoretic mobility shift assay as well as the induced-degradation of IkappaB-alpha protein by LPS or TNF-alpha. Further analysis revealed that manassantins A and B dose-dependently suppressed not only the induced NF-kappaB activation by overexpression of RelA/p65, but also transactivation activity of RelA/p65. Furthermore, treatment of cells with these compounds prevented the TNF-alpha-induced expression of anti-apoptotic NF-kappaB target genes Bfl-1/A1, a prosurvival Bcl-2 homologue, and resulted in sensitizing HT-1080 cells to TNF-alpha-induced cell death. Similarly, these compounds also suppressed the LPS-induced inducible nitric oxide synthase expression and nitric oxide production. Taken together, manassantins A and B could be valuable candidate for the intervention of NF-kappaB-dependent pathological condition such as inflammation and cancer.     

Pharmacology and clinical experience with simvastatin

Simvastatin (Zocortrade mark, Merck) is a safe and effective 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. Simvastatin potently lowers total and low density lipoprotein (LDL) cholesterol. Simvastatin was the first cholesterol-lowering agent that reduced total mortality in a randomised clinical trial. Simvastatin is effective at reducing total mortality, myocardial infarction, coronary mortality and the incidence of stroke or transient ischemic attack in patients with coronary heart disease and hypercholesterolemia. Simvastatin, like other statins, also has non-lipid mechanisms of action. These include anti-inflammatory effects, antiproliferative effects on smooth muscle cells and an upregulation of endothelial nitric oxide synthase. Overall, simvastatin has an excellent safety profile. Simvastatin, along with other statins, has made a significant impact on the morbidity and mortality from coronary heart disease.     

Pharmacology and clinical experience with simvastatin

Simvastatin (Zocor?, Merck) is a safe and effective 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. Simvastatin potently lowers total and low density lipoprotein (LDL) cholesterol. Simvastatin was the first cholesterol-lowering agent that reduced total mortality in a randomised clinical trial. Simvastatin is effective at reducing total mortality, myocardial infarction, coronary mortality and the incidence of stroke or transient ischemic attack in patients with coronary heart disease and hypercholesterolemia. Simvastatin, like other statins, also has non-lipid mechanisms of action. These include anti-inflammatory effects, antiproliferative effects on smooth muscle cells and an upregulation of endothelial nitric oxide synthase. Overall, simvastatin has an excellent safety profile. Simvastatin, along with other statins, has made a significant impact on the morbidity and mortality from coronary heart disease.