No abstract

Acetaminophen (APAP) overdose could induce liver damage and lead to acute liver failure. The treatment of APAP overdoses could be improved by new therapeutic strategies. Thymus spp., which has many beneficial effects and has been used in folk medicine, is one such potential strategy. In the present study, the hepatoprotective activity of the main constituents of Thymus spp., carvacrol and thymol, were evaluated in light of APAP-induced hepatotoxicity. We hoped to understand the hepatoprotective mechanism of these agents on the antioxidant system and pro-inflammatory cytokines in vitro. Dose-dependent effects of thymol and carvacrol (25, 50, and 100 µM) were tested on cultured HepG2 cells. N-Acetylcysteine (NAC) was tested as positive control. We showed that APAP inhibited HepG2 cell growth by inducing inflammation and oxidative stress. Incubating APAP-exposed HepG2 cells with carvacrol and thymol for 24 h ameliorated this inflammation and oxidative stress. We also evaluated alanine transaminase and lactate dehydrogenase levels of HepG2 cells. We found that thymol and carvacrol protected against APAP-induced toxicity in HepG2 cells by increasing antioxidant activity and reducing pro-inflammatory cytokines, such as tumor necrosis factor α and interleukin 1β. Taking together high-dose thymol and carvacrol treatment has an effect close to NAC treatment in APAP toxicity, but thymol has better treatment effect than carvacrol.

No abstract

Workers in denim sandblasting are at a high risk of developing silicosis, an occupational lung disease caused by inhaling crystalline silica dust. The development and progress of silicosis is associated with the activation of the immune system and oxidative stress. In the former, interferon-gamma induces both neopterin release and the enzyme indoleamine [2, 3]-dioxygenase (IDO) in various cells. The determination of the kynurenine-to-tryptophan ratio and neopterin concentration has proven to be an efficient method to monitor the activation status of IDO and cellular immunity. The present study aimed to investigate whether occupational silica exposure leads to any alterations in neopterin levels, tryptophan degradation, and activities of superoxide dismutase (SOD) and catalase (CAT), agents in the antioxidant defense system. Fifty-five male denim sandblasting workers and twenty-two healthy men as controls were included. Mean neopterin and kynurenine levels, kynurenine-to-tryptophan ratio, and SOD activity were higher in subjects with silicosis compared to non-exposed controls (all, p<0.05). Neopterin levels and kynurenine-totryptophan ratios were positively correlated (p<0.05); however, no correlation was observed between length of employment and the measured parameters. Some of the measured parameters were significantly affected by the severity of the pathology. Our results suggest that silica exposure activates the cellular immune response. The increased neopterin levels and tryptophan degradation confirm the possibility of their use as an indicator of cellular immune response.

A simple high-performance liquid chromatography (HPLC) method has been developed for determination of diclofenac in human plasma. The method was validated on Ace C(18) column using UV detection. The mobile phase consisted of 20 mM phosphate buffer (pH 7) containing 0.1% trifluoroacetic acid-acetonitrile (65:35, v/v). Calibration curve was linear between the concentration range of 75-4000 ng/mL. Intra- and inter-day precision values for diclofenac in plasma were less than 3.6, and accuracy (relative error) was better than 5.3%. The limits of detection and quantification of diclofenac were 25 and 75 ng/mL, respectively. Also, this assay was applied to determine the pharmacokinetic parameters of diclofenac in healthy Turkish volunteers who had been given 50 mg diclofenac.

Paracetamol is one of the most popular and widely used analgesic and antipyretic agents, but an overdose can cause hepatotoxicity and lead to acute liver failure. Aliskiren directly inhibits renin which downregulates the renin-angiotensin-aldosterone system (RAAS). Recent findings suggest that RAAS system takes part in the pathogenesis of liver fibrosis. We aimed to reveal the relationship between hepatotoxicity and the RAAS by examining paracetamol induced hepatotoxicity. Rats were separated into five groups as follows: control, 100 mg/kg aliskiren (p.o.), 2 g/kg paracetamol (per os (p.o.)), 2 g/kg paracetamol + 50mg/kg aliskiren (p.o.), and 2 g/kg paracetamol + 100 mg/kg aliskiren(p.o.). Samples were analyzed at the biochemical, molecular, and histopathological levels. Paracetamol toxicity increased alanine aminotransferases (ALT), aspartate aminotransferases (AST), renin, and angiotensin II levels in the serum samples. In addition, the SOD activity and glutathione (GSH) levels decreased while Lipid Peroxidation (MDA) levels increased in the livers of the rats treated with paracetamol. Paracetamol toxicity caused a significant increase in TNF-α and TGF-β. Both aliskiren doses showed an improvement in ALT, AST, oxidative parameters, angiotensin II, and inflammatory cytokines. Only renin levels increased in aliskiren treatment groups due to its pharmacological effect. A histopathological examination of the liver showed that aliskiren administration ameliorated the paracetamol-induced liver damage. In immunohistochemical staining, the expression of TNF-α in the cytoplasm of the hepatocytes was increased in the paracetamol group but not in other treatment groups when compared to the control group. In light of these observations, we suggest that the therapeutic administration of aliskiren prevented oxidative stress and cytokine changes and also protected liver tissues during paracetamol toxicity by inhibiting the RAAS.

No abstract

Contrast media (CM) is known to have nephrotoxic adverse effects. Epigallocatechin-3-gallate (EGCG) is the most abundant and active catechin in green tea, and has strong antioxidant and anti-inflammatory properties. This study investigated whether EGCG can reduce contrast-induced nephrotoxicity (CIN), alone or with glycerol (GLY)-induced renal damage, and to understand its mechanisms of protection against toxicity, using models of GLY and CIN in rats. The rats were separated into eight groups (n = 6 in each), as follows: Healthy, GLY, CM, GLY + CM, CM + EGCG 50 mg/kg (po), GLY + CM + EGCG 50 mg/kg (po), CM + EGCG 100 mg/kg (po), and GLY + CM + EGCG 100 mg/kg (po). Both doses of EGCG protected against CM-induced renal dysfunction, as measured by serum creatinine and blood urea nitrogen (BUN). In addition, EGCG treatment markedly improved CIN-induced oxidative stress, and resulted in a significant down-regulatory effect on tumor necrosis factor (TNF)-α and nuclear factor (NF)-κB mRNA expression. Moreover, histopathological analysis showed that EGCG also attenuated CM-induced kidney damage. Considering the potential clinical use of CM and the numerous health benefits of EGCG, this study showed the protective role of multi-dose EGCG treatment on CIN and GLY-aggravated CIN through different mechanisms.