Metformin alleviates inflammation in oxazolone induced ulcerative colitis in rats: plausible role of sphingosine kinase 1/sphingosine 1 phosphate signaling pathway.

OBJECTIVES: Ulcerative colitis (UC) is a chronic inflammatory bowel disease that is associated with high sphingosine kinase 1(SPHK1) expression in the colon, however its role in pathogenesis of UC is not clearly understood so, the aim of the present study was to clarify the role of SPHK1 and investigate whether the anti-inflammatory effects of metformin in UC is mediated by Sphingosine kinase 1/sphingosine 1 phosphate (S1P) signaling pathway. MATERIAL AND METHODS: Colitis was induced in adult male wistar rats by intra rectal administration of oxazolone in the fifth and seventh days from initial presensitization. Oxazolone treated rats were divided into untreated oxazolone group, metformin and mesalazine treated groups both in a dose of 100 mg/kg/day orally for 21 days. Along with these groups normal control and saline groups were used .Colitis was assessed by colon length, disease activity index (DAI) and histological examination of colontissue. Plasma samples were used to measure S1P.SPHK1 activity, signal transducer and activator of transcription -3(STAT-3), interleukin-6 (IL-6), nitric oxide (NO), myeloperoxidase activity (MPO), reduced glutathione (GSH) and tissue expression of intracellular cell adhesion molecule -1(ICAM-1) and caspase-3 genes were measured in tissue. RESULTS: Metformin successfully attenuated oxazolone colitis by increasing colon length, decreasing DAI and improved colon histologic picture. Metformin also induced a significant decrease in Plasma SIP, SPHK1 activity, inflammatory, oxidative stress markers, ICAM-1 and Caspase-3 genes expression compared to oxazolone group. CONCLUSION: It is revealed that metformin alleviated inflammation and underlying mechanism may result from inhibition of SPHK1/S1P signaling pathway.

Protective role of naftidrofuryl against methotrexate-induced testicular damage via the amelioration of the p53/miRNA-29a/CDC42 apoptotic pathway, inflammation, and oxidative stress.

This study aimed to assess the possible protective effects of naftidrofuryl (Naf) against methotrexate (MTX)-induced testicular toxicity in rats. Male rats were randomly distributed into four groups: control, Naf, MTX, and MTX+Naf groups. MTX administration induced oxidative stress, inflammation, and apoptosis in the testicular tissue, while pretreatment with Naf attenuated these pathways. Naf pretreatment significantly decreased malondialdehyde and interleukin-6 contents, microRNA-29a (miRNA-29a) expression level, and nuclear factor kappa B and p53 immunostaining in the testicular tissues compared to the MTX group. Conversely, it significantly increased Johnsen's score, serum testosterone level, serum total antioxidant capacity, testicular superoxide dismutase activity, testicular catalase activity, and testicular cell division cycle 42 (CDC42) expression compared to the MTX group. In conclusion, Naf exerted a significant protective effect against MTX-induced testicular toxicity via antioxidant and anti-inflammatory mechanisms and modulating the p53/miRNA-29a/CDC42 apoptotic pathway.

Targeting IL-10, ZO-1 gene expression and IL-6/STAT-3 trans-signaling by a combination of atorvastatin and mesalazine to enhance anti-inflammatory effects and attenuates progression of oxazolone-induced colitis.

Ulcerative colitis (UC) is a chronic inflammatory disease characterized by diffused inflammation of the colon and rectum mucosa. The pathogenesis of UC is multifactorial, and the exact underlying mechanisms remain poorly understood. This study aims to investigate the effect of mesalazine and atorvastatin combination in enhancing anti-inflammatory effects and attenuates progression of oxazolone colitis in rats. In the present study, male albino rats (N = 60) were divided into six groups (10 rats each), the first two groups served as normal control and a control saline group. Colitis was induced by intra-rectal administration of oxazolone in the 5th and 7th days after pre-sensitization. Then, rats were divided into untreated group, groups treated with mesalazine or atorvastatin or their combination. Colitis was assessed by colon length, body weight, and incidence of diarrhea, rectal bleeding, and histopathology of colon tissue. Colon tissues were used for measuring interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), IL-13, signal transducer and activator of transcription-3 (STAT-3), myeloperoxidase activity (MPO), reduced glutathione(GSH), and tissue expression of IL-10, tight junction protein zonula occludens (ZO-1), and caspase-3 genes. The combination therapy significantly attenuated progression of UC by decreasing incidence of diarrhea, rectal bleeding, weight loss, IL-13, IL-6, TNF-α, STAT-3, caspase-3, and MPO activity and significantly increased IL-10, ZO-1, colon length, and GSH content, and these effects were more superior to single drugs. These findings showed that combination therapy was able to ameliorate progression of UC and enhance anti-inflammatory effects possibly by restoring IL-10 and ZO-1 levels and limiting IL-6/STAT-3 trans-signaling.

Combination of telmisartan with sildenafil ameliorate progression of diabetic nephropathy in streptozotocin-induced diabetic model.

Diabetic nephropathy (DN) is a leading cause of end-stage renal disease in the world. Several signaling pathways are involved in the pathogenesis of DN including elevation in level of angiotensin II, formation of advanced glycation end products (AGE), activation of protein kinase c (PKC), and lipid accumulation. These pathways activate one another mutually leading to oxidative stress, increasing expression of transforming growth factor beta-1(TGF-ß 1) and release of interleukins and adhesion molecules, so the aim of this study is to interrupt more than pathogenic pathway to ameliorate the progression of DN. In the present study, white male rats (N=48) were divided into six groups (8 rats each), the first two groups served as normal control and a control vehicle group while the remaining four groups were rendered diabetic by a single intraperitoneal injection of Streptozotocin (STZ) and being left for 4 weeks to develop DN. Thereafter, the rats were divided into DN group, DN group receiving Telmisartan or Sildenafil or Telmisartan Sildenafil combination. After the specified treatment period, urine samples were collected (using metabolic cages) to measure proteinuria, animals were then euthanized, blood and tissue samples were collected for measurement of Blood glucose,BUN, S.Cr, LDL, NO, TGF-ß1, IL-1ß, AGEPs, and SOD. The combination therapy showed significant decrease in BUN, S.Cr,LDL, TGF-ß1, IL-1ß, Proteinuria and AGEPs and significant increase in SOD and NO. The findings showed that combination therapy was able to ameliorate DN and that the effects were superior to the single drugs alone.