Fingolimod ameliorates acetic acid-induced ulcerative colitis: An insight into its modulatory impact on pro/anti-inflammatory cytokines and AKT/mTOR signalling.

BACKGROUND: Because of the approved immunomodulatory activities of fingolimod, the current study aimed at studying the curative potential of fingolimod against experimentally induced ulcerative colitis (UC) via modulating pro/anti-inflammatory cytokines release and AKT/mTOR signalling. METHODS: UC was induced in rats by intracolonic instillation of acetic acid. Fingo (0.5 mg/kg/day, p.o.) was given for 8 consecutive days that started 48 h after UC induction. RESULTS: Fingolimod increased body weight growth rate and colon body/weight and colon weight/length indices compared to the UC group. Fingolimod significantly decreased clinical evaluation score and macroscopic score compared to the UC group. The curative potential of fingolimod was further confirmed by histopathological examination revealing marked attenuation of mucosal injury and inflammatory cells infiltration. Fingolimod significantly decreased colon malondialdehyde content and increased colon glutathione contents compared to the UC group. Fingolimod also significantly decreased the expressions of pro-inflammatory cytokines interleukin-9 and T-helper 17 along with increasing the expression of anti-inflammatory interleukin-10 and transforming growth factor-ß compared to the UC group. In addition, fingolimod decreased the expressions of AKT and mTOR compared to the UC group. CONCLUSION: Fingolimod attenuated acetic acid-induced UC through its immunomodulatory effect by shifting the balance to favour anti-inflammatory cytokine production rather than pro-inflammatory cytokines and modulating the AKT/mTOR signalling.

Hepatoprotective effect of the tyrosine kinase inhibitor nilotinib against cyclosporine-A induced liver injury in rats through blocking the Bax/Cytochrome C/caspase-3 apoptotic signaling pathway.

Cyclosporine-A (CsA) is a powerful immunosuppressive agent and hepatotoxicity results from CsA treatment. This study aimed to elucidate the effectiveness of tyrosine kinase inhibitor nilotinib against CsA-induced hepatotoxicity and the underlying molecular mechanisms. Male Sprague-Dawley rats were allocated into four groups and received drugs for 28 days as follows: Control group: received vehicle, Nilotinib group: received nilotinib (20 mg/kg orally), CsA group: received CsA by subcutaneous injection (20 mg/kg daily), CsA-nilotinib: received nilotinib and CsA. Serum lactate dehydrogenase (LDH), liver function biomarkers, hepatic levels of oxidative stress biomarkers, nuclear factor erythroid-2 like-2 (Nrf2), total antioxidant capacity (TAC), interleukin-2 (IL-2), IL-1ß, IL-6, and cytochrome-C were assessed. Additionally, the protein levels and mRNA expression of Bcl2 associated X protein (Bax), caspase-3, nuclear factor-κB (NF-κB), hemoxygenase-1 (HO-1) were measured. Moreover, liver tissues were assessed histopathologically using hematoxylin-eosin and Masson trichrome stain. Nilotinib treatment decreased serum LDH, alanine aminotransferase, aspartate aminotransferase, and γ-glutamyltransferase (γ-GT), hepatic malondialdehyde, and cytochrome-C. It also increased superoxide dismutase, reduced glutathione, glutathione reductase, glutathione peroxidase, glutathione-S-transferase (GST), TAC, and Nrf2 compared to CsA-injected rats. In addition, nilotinib decreased NF-κB, IL-1ß, IL-6, Bax, and caspase-3, while elevated IL-2 and immunoexpression of HO-1. Additionally, mRNA expression of Bax and caspase-3 was elevated and that of HO-1 and inhibitory protein κB-α was reduced in the nilotinib-treated group. Moreover, nilotinib significantly attenuated CsA-induced histopathological alterations. Nilotinib may have a promising role as a hepato-protective through its antiapoptotic, antioxidant, and anti-inflammatory effects.

Evaluation of the therapeutic effects of mycophenolate mofetil targeting Nrf-2 and NLRP3 inflammasome in acetic acid induced ulcerative colitis in rats.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that increases the risk of colorectal cancer. UC is highly associated with the disturbance of the immune system leading to oxidative stress and chronic inflammation of intestine. Therefore, the current study was conducted to investigate the potential anti-oxidant and anti-inflammatory effects of MMF against acetic acid-induced UC that might be associated with the regulation of Nrf-2 and NLRP3 inflammasome signaling. UC was induced in Sprague-Dawley rats by intracolonic instillation of acetic acid. Forty-eight hours post UC induction, MMF (50 mg/kg/day, orally) was given for 8 consecutive days. Then, colon tissues and blood samples were collected. Results showed that MMF significantly attenuated the acetic acid-induced functional, biochemical, and inflammatory injuries in colon. MMF significantly decreased oxidative stress as indicated by the decreased malondialdehyde concentration and the increased total antioxidant capacity, glutathione, catalase, and superoxide dismutase concentrations in colon tissues. MMF also significantly increased Nrf-2 and decreased NLRP3 inflammasome expressions. Moreover, MMF decreased expression of interferon-gamma and increased expression of interferon-alpha. MMF also significantly decreased expression of pro-inflammatory cytokines, interleukin (IL)-1ß and IL-18. These results suggest that MMF has antioxidant and anti-inflammatory effects against acetic acid-induced UC through the upregulation of Nrf-2, and INF-α expression in addition to the suppression of NLRP3 inflammasome and subsequent release of IL1ß, IL-18 and INF-γ.

Pirfenidone attenuates gentamicin-induced acute kidney injury by inhibiting inflammasome-dependent NLRP3 pathway in rats.

Acute kidney injury (AKI) is an abrupt and usually reversible decline in renal function. AKI is considered one of the main drawbacks of the use of gentamicin that critically limits its clinical use. In this study, pirfenidone, an oral antifibrotic drug, was given to rats (200 mg/kg, p.o., daily) for seven days alone before the initiation of gentamicin treatment and continued for seven days alongside daily gentamicin injections. In gentamicin group, gentamicin was given to Wistar rats (100 mg/kg, i.p., daily) for seven days to induce AKI. Pirfenidone managed to alleviate gentamicin-induced AKI by improving kidney function parameters including serum creatinine, blood urea nitrogen (BUN), proteinuria, relative kidney-to-body weight ratio and creatinine clearance. Pirfenidone decreased cytotoxicity induced by gentamicin by decreasing lactate dehydrogenase (LDH) activity and improving histologic picture of tubules and glomeruli. Pirfenidone also alleviated oxidative stress induced by gentamicin by reducing malondialdehyde (MDA) and elevating reduced glutathione (GSH). Pirfenidone prevented the upregulated inflammasome pathway markers in the kidney. It succeeded in decreasing toll like recpetor-4 (TLR4), nuclear factor-kappa B (NF-κB), nucleotide-binding oligomerization domain [NOD]-like pyrin domain containing protein 3 (NLRP3), caspase-1, interleukin-1ß (IL-1ß) and IL-18 levels. Additionally, Pirfenidone caused a decrease in macrophage infiltration displayed by reduction in renal monocyte chemoattractant protein-1 (MCP-1) levels. To sum up, pirfenidone can effectively mitigate gentamicin-induced AKI by inhibiting oxidative stress, macrophage infiltration and inflammasome-dependent NLRP3 pathway-induced inflammation.

Mycophenolate mofetil attenuates concanavalin A-induced acute liver injury through modulation of TLR4/NF-κB and Nrf2/HO-1 pathways.

BACKGROUND: Acute liver injury (ALI) is a serious health condition associated with rising morbidity and sudden progression. This study was designed to investigate the possible hepatocurative potential of two dose levels (30 and 60 mg/kg) of Mycophenolate mofetil (MMF), an immune-suppressant agent, against Concanavalin A (Con A)-induced ALI in mice. METHOD: A single dose of Con A (20 mg/kg, IV) was used to induce ALI in mice. MMF (30 mg/kg and 60 mg/kg) was administered orally for 4 days post Con A injection. RESULTS: MMF (30 mg/kg) failed to cause significant amelioration in Con A-induced ALI while MMF (60 mg/kg) significantly alleviated Con A-induced ALI. Administration of MMF (60 mg/kg) significantly decreased Con A-induced increase in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Additionally, MMF significantly restored the disrupted oxidant/antioxidants status induced by Con A. MMF caused marked increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels. Moreover, MMF significantly reduced Con A-induced increase in the expression of hepatic toll-like receptor 4 (TLR4), nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ) and interleukin-1ß (Il-1ß). Also, MMF administration significantly decreased Con A-induced increase in the immune-expression of pro-apoptotic Bcl-2-associated X protein (Bax) and markedly increased Con A-induced decrease in the anti-apoptotic B-cell lymphoma 2 protein (Bcl2). CONCLUSION: The observed ameliorative effect of MMF against Con A-induce ALI may be contributed to its anti-inflammatory, anti-oxidant and anti-apoptotic potentials taking into consideration that TLR4/NF-κB and Nrf2/HO-1 are the main implicated pathways. Schematic diagram summarizing the possible mechanisms underlying the ameliorative potential of Mycophenolate Mofetil against Con A-induced acute liver injury. Bax Bcl-2-associated X protein, Bcl2 B-cell lymphoma 2, MMF Mycophenolate mofetil, Con A Concanavalin A, GSH reduced glutathione, HO-1 Heme oxygenase-1, IL-1ß Interleukin-1ß, IFN-γ Interferon-γ, MDA Malondialdehyde, NF-κB Nuclear Factor Kappa B, Nrf2 Nuclear factor erythroid 2-related factor 2, NO Nitric Oxide, SOD Superoxide Dismutase, TLR4 Toll-like receptor 4, TNF-α tumor necrosis factor-α.

Sitagliptin ameliorates thioacetamide-induced acute liver injury via modulating TLR4/NF-KB signaling pathway in mice.

Sitagliptin is an oral hypoglycemic drug that acts by selective inhibition of dipeptidyl peptidase-4 (DDP-4) enzyme. AIM: This study scrutinized the hepatoprotective impact of sitagliptin) against thioacetamide (TAA)-induced liver damage in mice. MAIN METHODS: Male mice were injected with TAA (500 mg/kg) then treated with sitagliptin (20 mg/kg) orally for 5 days. KEY FINDINGS: Histopathological results of TAA group revealed severe degree of centrolobular hepatic necrosis. Additionally, biochemical findings showed marked elevation in the serum transaminases and gamma glutamyl transpeptidase (GGT) levels in TAA group. Injection of TAA significantly disrupted oxidant/antioxidants hemostasis of the hepatic tissues. Also, TAA markedly increased the expression of nuclear factor kappa-B (NF-KB); and enhanced Toll like receptor 4 (TLR4) as well as NLPR3 inflammosome production. Moreover, there was an elevation in the hepatic levels of tumor necrosis factor-alpha (TNF-α) and interleukin -1 beta (IL-1ß) besides increased immunoexpression of Bcl-2-associated X protein (Bax) as well as caspase 3. In contrast, treatment with sitagliptin significantly attenuated TAA-induced histopathological, biochemical and immunohistochemical alterations. SIGNIFICANCE: Our results suggest that the hepatoprophylactic impact of sitagliptin might be arbitrated via modulating TLR4 and NK-KB signaling cascade followed by depression of inflammation besides apoptosis.

The heat shock protein 90 inhibitor, 17-AAG, attenuates thioacetamide induced liver fibrosis in mice.

BACKGROUND: Heat shock protein 90 (Hsp90) is proposed to be involved in liver disorders. This study was conducted to test effect of 17-N-allylamino-17-demethoxygeldanamycin (17-AAG), an inhibitor of Hsp90, on attenuating thioacetamide induced liver fibrosis in vivo. METHODS: Four groups of Swiss albino male mice (CD-1 strain) were used as follows: control group; thioacetamide group (received 100mg/kg thioacetamide, ip injection, 3 times/week for 8 weeks); thioacetamide plus 17-AAG groups (received 100mg/kg thioacetamide, ip injection, 3 times/week for 8 weeks plus 25 or 50mg/kg 17-AAG, ip injection, 5 days/week along the last 4 weeks). Fibrosis was quantified by measuring hydroxyproline level and by morphometry and oxidative stress biomarkers were assigned. Relative hepatic mRNA expressions of α-smooth muscle actin (α-SMA), collagen-1-alpha-1 (Col1A1) and tissue inhibitor metalloproteinase-1 (TIMP-1) mRNAs were measured by RT-PCR. Levels of the apoptotic markers caspase-3, factor related apoptosis (Fas) and Hsp-90 were assigned in tissue homogenate. RESULTS: 17-AAG (50mg/kg) significantly decreased fibrosis percentage significantly (p<0.001, 0.05) compared to thioaceatmide and 25mg/kg, respectively. Malondialdehyde, Hsp90, α-SMA, Col1A1 and TIMP-1 expression levels were significantly reduced (p<0.05) by the inhibitor large dose. Levels of GSH, caspase-3 and Fas were markedly (p<0.001) increased in the group received 17-AAG (50mg/kg) compared to other groups. CONCLUSION: The Hsp90 inhibitor, 17-AAG, can attenuate thioacetamide hepatotoxicity through oxidative stress counterbalance, reducing stellate cells activity and inducing apoptosis.