Nicorandil and atorvastatin attenuate carbon tetrachloride - induced liver fibrosis in rats

Therapeutic potential of nicorandil beyond anti-anginal drug: A review on current and future perspectives

Nicorandil (NIC) is a well-known anti-anginal agent, which has been recommended as one of the second-line treatments for chronic stable angina as justified by the European guidelines. It shows an efficacy equivalent to that of classic anti-anginal agents. NIC has also been used clinically in various cardiovascular diseases such as variant or unstable angina and reperfusion-induced damage following coronary angioplasty or thrombolysis. Different mechanisms have been involved in the protective effects of nicorandil in various diseases, including opening of adenosine triphosphate-sensitive potassium (KATP) channel and donation of nitric oxide (NO). In recent years, NIC has been found to show numerous pharmacological activities such as neuroprotective, nephroprotective, hepatoprotective, cardioprotective, and testicular protective effects, among other beneficial effects on the body. The present review dwells on the pharmacological potentials of NIC beyond its anti-anginal action.

Inflammation drives pathogenesis of early intestinal failure-associated liver disease

Patients with intestinal failure who receive long-term parenteral nutrition (PN) often develop intestinal failure-associated liver disease (IFALD). Although there are identified risk factors, the early pathogenesis is poorly understood and treatment options are limited. Here, we perform a transcriptomic analysis of liver tissue in a large animal IFALD model to generate mechanistic insights and identify therapeutic targets. Preterm Yorkshire piglets were provided PN or bottle-fed with sow-milk replacer for 14 days. Compared to bottle-fed controls, piglets receiving PN developed biochemical cholestasis by day of life 15 (total bilirubin 0.2 vs. 2.9 mg/dL, P = 0.01). RNA-Seq of liver tissue was performed. Ingenuity Pathway Analysis identified 747 differentially expressed genes (343 upregulated and 404 downregulated) with an adjusted P < 0.05 and a fold-change of > |1|. Enriched canonical pathways were identified, demonstrating broad activation of inflammatory pathways and inhibition of cell cycle progression. Potential therapeutics including infliximab, glucocorticoids, statins, and obeticholic acid were identified as predicted upstream master regulators that may reverse the PN-induced gene dysregulation. The early driver of IFALD in neonates may be inflammation with an immature liver; identified therapeutics that target the inflammatory response in the liver should be investigated as potential treatments.

Nicorandil/ morphine crosstalk accounts for antinociception and hepatoprotection in hepatic fibrosis in rats: Distinct roles of opioid/cGMP and NO/KATP pathways

Previous report indicated that nicorandil potentiated morphine antinociception and attenuated hepatic injury in liver fibrotic rats. Herein, the underlying mechanisms of nicorandil/morphine interaction were investigated using pharmacological, biochemical, histopathological, and molecular docking studies. Male Wistar rats were injected intraperitoneally (i.p.) with carbon tetrachloride (CCl4, 40%, 2 ml/kg) twice weekly for 5 weeks to induce hepatic fibrosis. Nicorandil (15 mg/kg/day) was administered per os (p.o.) for 14 days in presence of the blockers; glibenclamide (KATP channel blocker, 5 mg/kg, p.o.), L-NG-nitro-arginine methyl ester (L-NAME, nitric oxide synthase inhibitor, 15 mg/kg, p.o.), methylene blue (MB, guanylyl cyclase inhibitor, 2 mg/kg, i.p.) and naltrexone (opioid antagonist, 20 mg/kg, i.p.). At the end of the 5th week, analgesia was evaluated using tail flick and formalin tests along with biochemical determinations of liver function tests, oxidative stress markers and histopathological examination of liver tissues. Naltrexone and MB inhibited the antinociceptive activity of the combination. Furthermore, combined nicorandil/morphine regimen attenuated the release of endogenous peptides. Docking studies revealed a possible interaction of nicorandil on µ, κ and δ opioid receptors. Nicorandil/morphine combination protected against liver damage as evident by decreased liver enzymes, liver index, hyaluronic acid, lipid peroxidation, fibrotic insults, and increased superoxide dismutase activity. Nicorandil/morphine hepatoprotection and antioxidant activity were inhibited by glibenclamide and L-NAME but not by naltrexone or MB. These findings implicate opioid activation/cGMP versus NO/KATP channels in the augmented antinociception, and hepatoprotection, respectively, of the combined therapy and implicate provoked cross talk by nicorandil and morphine on opioid receptors and cGMP signaling pathway. That said, nicorandil/morphine combination provides a potential multitargeted therapy to alleviate pain and preserve liver function.

Nicorandil reduces morphine withdrawal symptoms, potentiates morphine antinociception, and ameliorates liver fibrosis in rats

AIMS

Chronic liver disease (CLD) is a serious medical condition affecting patients globally and pain management poses a unique challenge. ATP-sensitive potassium channels (K_ATP) are expressed in nociceptive neurons and hepatic cells. We tested the hypothesis whether morphine and nicorandil, K_ATP channel opener, alone and in combination possess hepatoprotective, antinociceptive effect and alter morphine physical dependence.

MAIN METHODS

Intraperitoneal injection (i.p.) of carbon tetrachloride (CCl₄) induced liver fibrosis in male Wistar rats. Nicorandil (15 mg/kg/day) was administered per os for two weeks. Morphine (3.8, 5, 10 mg/kg, i.p.) was administered prior to antinociception testing in tail flick and formalin tests. Morphine physical dependence following naloxone injection, fibrotic, oxidative stress markers, and liver histopathology were assessed.

KEY FINDINGS

Morphine alone, produced insignificant changes of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), hepatic hydroxyproline (Hyp), malondialdehyde (MDA), and superoxide dismutase (SOD) levels and exerted significant antinociception in the pain models. Nicorandil alone protected against liver damage (decreased serum ALT, AST, HA, hepatic Hyp, MDA, increased SOD levels, improved fibrosis scores). Nicorandil/morphine combination produced remarkable hepatoprotection and persistent analgesia compared to morphine alone as evidenced by reduced (EC50) of morphine. Nicorandil augmented morphine analgesia and markedly decreased withdrawal signs in morphine-dependent rats.

SIGNIFICANCE

The data showed for the first time, the hepatoprotection and augmented antinociception mediated by nicorandil/morphine combination in liver fibrosis via antioxidant and antifibrotic mechanisms. Nicorandil ameliorated withdrawal signs in morphine dependence in CLD. Thus, combining nicorandil/morphine provides a novel treatment strategy to ameliorate hepatic injury, potentiate antinociception and overcome morphine-induced physical dependence in liver fibrosis.

Pleiotropic Long-Term Effects of Atorvastatin on Posttraumatic Joint Contracture in a Rat Model

The antifibrotic effect of atorvastatin has already been demonstrated in several organ systems. In the present study, a rat model was used to investigate the effect of atorvastatin on posttraumatic joint contracture. Forty-eight Sprague Dawley rats were equally randomized into an atorvastatin group and a control group. After initial joint trauma, knee joints were immobilized for intervals of 2 weeks (n = 16) or 4 weeks (n = 16) or immobilized for 4 weeks with subsequent remobilization for another 4 weeks (n = 16). Starting from the day of surgery, animals received either atorvastatin or placebo daily. After euthanasia at week 2, 4 or 8, joint contracture was determined, histological examinations were performed, and gene expression was assessed. The results suggest that the joint contracture was primarily arthrogenic. Atorvastatin failed to significantly affect contracture formation and showed a reduction in myofibroblast numbers to 98 ± 58 (control: 319 ± 113, p < 0.01) and a reduction in joint capsule collagen to 60 ± 8% (control: 73 ± 9%, p < 0.05) at week 2. Gene expression of α-smooth muscle actin (α-SMA), collagen type I, transforming growth factor β1 (TGF-β1) and interleukin-6 (IL-6) was not significantly affected by atorvastatin. Atorvastatin decreases myofibroblast number and collagen deposition but does not result in an improvement in joint mobility.

Diminished CCl4 -induced hepatocellular carcinoma, oxidative stress, and apoptosis by co-administration of curcumin or selenium in mice

Hepatocellular carcinoma (HCC) is a lethal disease, and in HCC advanced stages, there is limited therapeutic efficacy. HCC results in a complication of fibrosis or cirrhosis. In this study, the protective effect of curcumin and selenium versus hepatocellular carcinoma caused by CCl₄ in experimental animals was investigated. In all, 70 mice were divided into seven groups to study the effect of curcumin and selenium on CCl₄ -induced hepatocellular carcinoma. After treatment time, different animal groups were sacrificed, serum and liver samples were collected and processed for assay of biochemical and molecular parameters. Our results showed that CCl₄ administration induced various alterations such as significant elevation in the serum levels of ALT, AST, and hepatic contents of malondialdehyde (MDA), and depletion in the levels of antioxidant parameters. CCl₄ induced apoptosis in the hepatic cells indicated by an increased level of p53, CD4, CD8, Bax, and Annexin V/PI in addition to significant decrease in the level of Bcl-2. Administration of curcumin and selenium restored this abnormal variation in these biochemical parameters to normal values. Our study addressed that curcumin or selenium may be helpful in the protection against liver damage induced by CCl₄ . The hepatoprotective impact of curcumin or selenium might be mediated primarily by its potent antioxidant activity. PRACTICAL APPLICATIONS: Hepatocellular carcinoma (HCC) ranked third common cause of death, primary liver cancer. Exposure to CCl₄ was found to induce significant hepatotoxicity, characterized by fibrosis, bile duct proliferation, cirrhosis, and reduced hepatic function The work was prepared to investigate the protecting capacity of curcumin, selenium alone, and in combination against HCC induced by CCl₄ in the experimental animal model. This study proved the protective effect of curcumin and selenium, alone and in combination with each other, where curcumin showed multiple pharmacological activities, including anti-inflammation and antioxidant, and have an essential role in inhibiting the progression of HCC.