Imatinib mitigates experimentally-induced ulcerative colitis: Possible contribution of NF-kB/JAK2/STAT3/COX2 signaling pathway

RATIONALE

Ulcerative colitis (UC) is a chronic immune-mediated disease characterized by recurrent inflammation, damage, and alteration of the large intestine's mucosal and submucosal surfaces. The purpose of this research was to evaluate the impact of tyrosine kinase inhibitor (imatinib) on experimentally induced UC in rats via acetic acid (AA).

METHODS

Male rats were randomly assigned to four groups: control, AA, AA + imatinib (10 mg/kg), and AA + imatinib (20 mg/kg). Imatinib (10 and 20 mg/kg/day) was orally supplied by oral syringe for one week before induction of UC. On the eighth day, Rats received enemas containing a 4 % solution of acetic acid to induce colitis. One day after inducing colitis, rats were euthanized and their colons were subjected to morphological, biochemical, histological, and immunohistochemical analysis.

RESULTS

Imatinib pretreatment significantly decreased macroscopic and histological damage scores, decreased disease activity index as well as colon mass index. In addition, imatinib successfully lowered the levels of malondialdehyde (MDA) in colonic tissues and enhanced superoxide dismutase activity (SOD) and glutathione content (GSH). Imatinib also reduced colonic levels of inflammatory interleukins (IL-23, IL-17, IL-6), JAK2 and STAT3. Furthermore, imatinib suppressed nuclear transcription factor kappa B (NF-kB/p65) level, and COX2 expression in colonic tissues.

SIGNIFICANCE

Imatinib may be a viable therapy option for UC as it halts the interaction network of NF-kB/JAK2/STAT3/COX2 signaling pathway.

Effect of Agmatine on a mouse model of allergic airway inflammation: A comparative study

INTRODUCTION

Asthma is a chronic lung disease that injures and constricts the airways. This study evaluates the effects of agmatine on ovalbumin (OVA)-induced allergic inflammation of the airways.

METHODS

OVA sensitization by intraperitoneal injection was used to induce airway inflammation in mice on days 0 and 7; then the mice were challenged using beclomethasone (150 µg/kg, inhalation), a standard anti-asthmatic drug, from day 14 to day 16. Furthermore, agmatine (200 mg/kg) was intraperitoneally injected on day 0 and then daily for 16 days, followed by OVA challenge. The lung weight ratio, total and differential cell counts, TNF-α, interleukin-5 (IL-5) and IL-13 in bronchoalveolar lavage fluid (BALF), lung nitrite/nitrate (NO), and oxidative parameters were determined. Moreover, histopathological and immunohistochemical staining was employed.

RESULTS

Injection of agmatine (200 mg/kg) for 16 days significantly attenuated inflammation of the airways. The levels of BALF inflammatory cells, TNF-α, IL-5, IL-13, lung NO, and malondialdehyde (MDA), significantly decreased with concomitant elevation of superoxide dismutase (SOD) levels. Histological and immunohistochemical analyses of mast cells paralleled to biochemical improvements.

CONCLUSION

Finally, this study illustrated that agmatine attenuates the allergic inflammation of airways caused by OVA by mitigating cytokines release, NO expression, and oxidative stress.

Canagliflozin ameliorates aortic and hepatic dysfunction in dietary-induced hypercholesterolemia in the rabbit

AIMS

Canagliflozin is an antidiabetic agent which lowers blood glucose levels by inhibiting the glucose reabsorption machinery in the proximal tubules. There have not been conducted any study on its direct impact on hypercholesterolemia and associated vascular disorders independently of blood glucose lowering activity.

MATERIALS AND METHODS

Rabbits were arranged in 3 groups: Group 1 (Control): regular rabbit chow; Group 2 (HCD): 1% cholesterol-enriched chow was given to rabbits for 4 weeks; Group 3 (HCD-CANA): 1% cholesterol-enriched chow was fed to rabbits concurrently with canagliflozin (10 mg/kg/day, orally) for 4 weeks. At the end of experiment, blood and tissue samples were obtained for biochemical, histological, immunohistochemical, and vascular reactivity assessment.

KEY FINDINGS

When statistically compared to Control (P < 0.05), HCD showed a significant increase in the serum triglycerides, low-density lipoprotein, total cholesterol, C-reactive protein, alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase. Furthermore, a significant decrease was seen in both liver and aortic levels of glutathione peroxidase and superoxide dismutase concurrently with a significant elevation in malondialdehyde levels. Aortic levels of nitrate/nitrite ratio were significantly elevated. Acetylcholine-induced relaxation was impaired as the E_max decreased significantly in aortae. Moreover, a significant increase was seen in the level of aortic intima/media ratio. Canagliflozin treatment significantly improved vascular function, lipid profile and inflammation and reduced liver injury.

SIGNIFICANCE

Our data suggest that SGLT-2 inhibition via canagliflozin not only possesses an antihyperglycemic activity, but also improves hypercholesterolemia, vascular and liver function in dietary-induced hypercholesterolemia in the rabbit.

The potential effect of imatinib against hypercholesterolemia induced atherosclerosis, endothelial dysfunction and hepatic injury in rabbits

AIMS

Imatinib is an effective tyrosine kinase inhibitor which has different therapeutic actions. The recent work demonstrated the possible beneficial effects of imatinib on the progression of atherosclerosis, endothelial dysfunction, and hypercholesterolemia-associated liver damage in rabbits.

MAIN METHODS

Animals had been distributed in 4 groups: group 1 (non-treated): animals fed regular diet; group 2 high cholesterol [HC]: animals fed 1% cholesterol supplemented diet for 30 days; group 3 (HC-Imatinib): animals fed 1% cholesterol supplemented diet+imatinib (0.01 g/kg daily, p.o) for 30 days; group 4 (Imatinib): animals fed regular diet with imatinib (0.01 g/kg daily, p.o). After thirty days, tissue samples and blood were isolated to be detected biochemically, histologically, and for in vitro analysis.

KEY FINDINGS

HC exhibited significant elevations in serum lipid parameters, CRP, ALT, AST and ALP. Additionally, HC induced significant increases for aortic and hepatic MDA, aortic NO and hepatic PDGFR-β, while significantly exhibited reductions in aortic and hepatic GSH, SOD and hepatic PPARγ1. Moreover, HC produced impairment in ACh-enhanced aortic relaxation and aortic pathological changes. Histopathological examination of HC-fed rabbits revealed hepatic steatosis compared with non-treated group. Imatinib administration exhibited significant decreases in serum lipid parameters, CRP, ALT, AST and ALP. Additionally, imatinib induced significant decreases for aortic and hepatic MDA, aortic NO and hepatic PDGFR-β, while significantly exhibited elevations in aortic and hepatic GSH, SOD and hepatic PPARγ1 compared with HC animals. Furthermore, imatinib significantly protected against HC produced attenuation in ACh-induced aortic relaxation and pathological changes in aortic and hepatic tissues. Interestingly, imatinib could return serum CRP, ALP, hepatic SOD and PDGFR-β to basal values.

SIGNIFICANCE

The recent observation reports that imatinib could have beneficial effect against atherosclerosis progression, vascular malfunction, and liver damage in high cholesterol diet (HCD)-fed rabbits.