Cilostazol attenuates indices of liver damage induced by thioacetamide in albino rats through regulating inflammatory cytokines and apoptotic biomarkers

Abstract

Even though cilostazol was assessed before in several models of atherosclerosis, so far its full systematic effect as a natural anti-inflammatory and anti-apoptotic mediator in the protection of liver damage and complication has not been fully clarified, which is the target of this study. For that purpose, we examined the protective effect of cilostazol (10 and 5 mg/kg, p.o. b.wt.) in an acute hepatic injury model by orally injecting it for 3 weeks prior to a single dose of TAA (300 mg/kg, i.p) injection. Ursodeoxycholic acid was used as a standard drug (50 mg/kg, p.o. b.wt.). After injection of thioacetamide by 48hr, rats were sacrificed. On the serum biochemical level, cilostazol ameliorated the thioacetamide consequence, where it presented a significant enhancement in the liver enzymes activities [Aspartate aminotransferase (AST) & Alanine aminotransferase (ALT)]. On the other hand, at the tissue level (Liver), it revealed a significant improvement in pro-inflammatory cytokines [Tumor necrosis factor alpha (TNF-α), Interleukin 1 beta (IL-1β), Nuclear factor kappa B (NF-κB), NF-κB (P65/P50 nucleus translocation), caspase-3, cleaved caspase-3 & C-reactive protein (CRP)], redox level [Reduced glutathione (GSH) & Malondialdehyde (MDA)], histopathological findings, Reverse transcription polymerase chain reaction (RT-PCR) analysis (expression of TNF-α and NF-κB mRNA levels), and immunohistochemical reaction (caspase-3 & TNF-α). Obviously, the high dose of cilostazol (10 mg/kg, p.o. b.wt.) displayed a more pronounced effect than its lower one and nearly equal to ursodeoxycholic acid in the most of the parameters. These results give a new awareness into the hopeful molecular mechanisms by which cilostazol attenuates several factors participated in the progression of liver damage.

Introduction

The liver is a highly vital organ, playing an important role in the metabolic functions. From the last years, the morbidity and mortality of many forms of liver diseases have increased all over the world (Trivedi and Hirschfield, 2013, Suk et al., 2014).

Cilostazol is a type III phosphodiesterase enzyme (PDE₃) inhibitor with partial type V phosphodiesterase (PDE₅) activity, which has been related to the elevation of the intracellular cyclic adenosine monophosphate (cAMP) level by preventing its hydrolysis (Kimura et al., 1985). Moreover, cilostazol reduces recurrent cerebral infarction (Gotoh et al., 2000) and mitigates ischemic brain injury post-transient focal cerebral ischemia by cyclic adenosine monophosphate response element binding protein (CREB) activator of progenitor cells and enhance hepatic blood flow and sinusoidal perfusion besides regulating pro-inflammatory cytokines (Akcan et al., 2006, Uchiyama, 2010).

Ursodeoxycholic acid is a secondary bile acid, which is a metabolic derivative of intestinal bacteria and it has anti-oxidative properties (Chun and Low, 2012). The positive effects of ursodeoxycholic acid in non-cholestatic liver injury is through preventing the damage of the liver mitochondrial functions and maintaining its structure in chronic alcohol toxicity (Lukivskaya et al., 2007). The mechanism of the ursodeoxycholic acid action could be related to the transposition of toxic bile acids from the bile acid pool as well as immunomodulatory and cytoprotective effects, and we used it in this study as a reference drug in evaluating cilostazol effects (Dilger et al., 2012, Kotb, 2012).

In this experiment, we decided to investigate the ability of cilostazol in combination with ursodeoxycholic acid in mitigating or restoring liver damage accompanied by inflammatory disorders, and complications.