Tomasz Sozański

Effect of simvastatin on nitric oxide synthases (eNOS, iNOS) and arginine and its derivatives (ADMA, SDMA) in ischemia/reperfusion injury in rat liver.

Hydroxymethylglutaryl-CoA reductase inhibitors play a role in nitric oxide synthesis. In this study, the impact of simvastatin (SV) on the levels of nitric oxide synthases, and arginine (Arg) and its derivatives was evaluated in rat liver under ischemia-reperfusion (I/R) conditions. Rats received SV (25 mg/kg) (groups S and S-IR) or saline solution (groups C and C-IR) intragastrically for 21 days. The livers of groups C and S were homogenized after treatment while those of groups C-IR and S-IR underwent ischemia and reperfusion before homogenization. Endothelial (eNOS) and inducible (iNOS) nitric oxide synthase concentrations were determined in the homogenates. Alanine and asparagine aminotransferase (ALT, AST, respectively), arginine (Arg), and asymmetric (ADMA) and symmetric (SDMA) methylarginine levels were determined in the blood before I/R and during reperfusion. I/R injury produced significant increases in aminotransferase, ADMA, eNOS, and iNOS, but decreases in Arg and Arg/ADMA levels. Arg concentration increased significantly after warm ischemia in the S-IR group, but decreased significantly during the first 30 minutes of reperfusion in both the S-IR and C-IR groups. eNOS concentration was significantly higher in group S than in group C. Both I/R and SV exerted no influence on SDMA concentration. SV exerted a protective action by increasing eNOS levels under normal conditions and Arg levels after ischemia and by preventing a significant increase in iNOS concentration after I/R. SV had no effect on ADMA concentration under normal and pathological conditions.

The protective effect of the Cornus mas fruits (cornelian cherry) on hypertriglyceridemia and atherosclerosis through PPARα activation in hypercholesterolemic rabbits.

Cornelian cherry (Cornus mas L.) fruits have been used in traditional cuisine and in folk medicine in various countries. This study was conducted to evaluate the constituents and impact of cornelian cherry (C. mas L.) fruits lyophilisate on lipid levels, PPARα protein expression, atheromatous changes in the aorta, oxido-redox state, and proinflammatory cytokines in hypercholesterolemic rabbits. The HPLC-MS method was used for determining active constituents in cornelian cherry. In a subsequent in vivo study the protective effect of the cornelian cherry on diet-induced hyperlipidemia was studied using a rabbit model fed 1% cholesterol. Cornelian cherry (100mg/kg b.w.) or simvastatin (5mg/kg b.w.) were administered orally for 60 days. Two iridoids - loganic acid and cornuside - and five anthocyanins were identified as the main constituents of the cornelian cherry. The administering of the cornelian cherry led to a 44% significant decrease in serum triglyceride levels, as well as prevented development of atheromatous changes in the thoracic aorta. Cornelian cherry significantly increased PPARα protein expression in the liver, indicating that its hypolipidemic effect may stem from enhanced fatty acid catabolism. Simvastatin treatment did not affect PPAR-α expression. Moreover, the cornelian cherry had a significant protective effect on diet-induced oxidative stress in the liver, as well as restored upregulated proinflammatory cytokines serum levels. In conclusion, we have shown loganic acid to be the main iridoid constituent in the European cultivar of the cornelian cherry, and proven that the cornelian cherry could have protective effects on diet-induced hypertriglicerydemia and atherosclerosis through enhanced PPARα protein expression and via regulating oxidative stress and inflammation.

Influence of commonly used clinical antidotes on antioxidant systems in human hepatocyte culture intoxicated with α-amanitin

α-Amanitin (α-AMA) is the main toxin of Amanita phalloides and its subspecies (A. virosa and A. verna). The primary mechanism of α-AMA toxicity is associated with protein synthesis blocking in hepatocytes. Additionally, α-AMA exhibits prooxidant properties that may contribute to its severe hepatotoxicity. The aim of the present study was to assess the effect of α-AMA on lipid peroxidation and the activities of superoxide dismutase (SOD) and catalase (CAT) in human hepatocyte culture. The effects of benzylpenicillin (BPCN), N-acetyl-L-cysteine (ACC), and silibinin (SIL) on SOD and CAT activities and on lipid peroxidation in human hepatocyte culture intoxicated with α-AMA were also examined. In human hepatocyte culture, 48-hour exposure to α-AMA at a 2-μM concentration caused an increase in SOD activity, a reduction of CAT activity, and a significant increase in lipid peroxidation. Changes in SOD and CAT activity caused by α-AMA could probably enhance lipid peroxidation by increased generation of hydrogen peroxide combined with reduced detoxification of that oxygen radical. The addition of antidotes (ACC or SIL) to the culture medium provided more effective protection against lipid peroxidation in human hepatocytes intoxicated with α-AMA than the addition of BPCN, possessing no antioxidant properties.

Effects of morin-5′-sulfonic acid sodium salt (NaMSA) on cyclophosphamide-induced changes in oxido-redox state in rat liver and kidney

Cyclophosphamide (CPX) is an anticancer drug with immunosuppressive properties. Its adverse effects are partly connected to the induction of oxidative stress. Some studies indicate that water-soluble derivative of morin—morin-5′-sulfonic acid sodium salt (NaMSA) exhibits strong antioxidant activity. The aim of present study was to evaluate the effect of NaMSA on CPX-induced changes in oxido-redox state in rat. Experiment was carried out on Wistar rats divided in three experimental groups (N = 12) receiving: 0.9% saline, CPX (15 mg/kg) or CPX (15 mg/kg) + NaMSA (100 mg/kg), respectively, and were given intragastrically for 10 days. Malondialdehyde (MDA) and glutathione (GSH) concentrations and superoxide dismutase (SOD) activity were determined in liver and kidneys. Catalase (CAT) activity was assessed only in liver. Treatment with CPX resulted in significant decrease in MDA level in both tissues, which was completely reversed by NaMSA treatment only in liver. In comparison to the control group significant decrease in SOD activity were observed in both tissues of CPX receiving group. In kidneys this parameter was fully restored by NaMSA administration. CPX evoked significant decrease in GSH concentration in kidneys, which was completely reversed by NaMSA treatment. No significant changes were seen in GSH levels and CAT activity between all groups in liver. Results of our study suggest that CPX may exert significant impact on oxido-redox state in both organs. NaMSA fully reversed the CPX-induced changes, especially MDA level in liver, SOD activity and GSH concentration in kidneys and it may be done by enhancement of activity/concentration of endogenous antioxidants.

Benzylpenicyllin and acetylcysteine protection from α-amanitin-induced apoptosis in human hepatocyte cultures

High mortality rate in Amanita phalloides (death cap) intoxications is a result of the acute liver failure following hepatocyte damage due to hepatocellular uptake of amatoxins. α-Amanitin (α-AMA), the major amatoxin, blocks a RNA polymerase II, which results in inhibition of transcription of DNA and protein synthesis processes and leads to hepatocyte death. α-AMA is also a strong apoptosis inductor and may play a significant role in pathogenesis of hepatic damage in course of amanitin intoxication. The aim of this study was to examine mechanisms of α-AMA-induced apoptosis in human hepatocytes, as well as in determining if commonly clinically used antidotes benzylpenicillin (BPCN) and N-acetylcysteine (ACC) are able to protect human hepatocytes against α-AMA-induced apoptosis. The experiment was performed on cultured human hepatocytes. Viability of cultured hepatocytes was assessed using the MTT assay, whereas apoptosis processes were evaluated by the electron microscopy, detection of DNA laddering, determination of caspase-3 activity, and measuring annexin V, p53 and Bcl-2 protein concentration. Cytotoxicity and apoptosis evaluation were performed after 24 h of exposure to α-AMA and/or tested antidotes.Both ACC and BPCN were well tolerated by human hepatocyte cultures, and exposure to those substances did not reduce cell viability nor induce apoptosis. Exposure of hepatocytes to α-AMA at concentration 2μM resulted in derangement of cell cultures, apoptosis and significant reduction in cell viability. α-AMA-induced apoptosis in human heptocyte cultures is p53- and caspase-3-dependent. Human hepatocyte cultures are exposed simultaneously to α-AMA and tested antidotes (BPCN or ACC) showed significantly higher cell viability and significantly lower values of apoptosis markers compared to the cultures exposed to α-AMA only.

Effects of melatonin on lipid peroxidation and antioxidative enzyme activities in the liver, kidneys and brain of rats administered with benzo(a)pyrene.

Benzo(a)pyrene [B(a)P] is a widespread pollutant with a mutagenic, carcinogenic and strong prooxidative properties. The present study evaluated the melatonin effects on lipid peroxidation products levels and on activity of antioxidative enzymes in the course of B(a)P intoxication. Control rats were treated with 0.9% NaCl; another group was given 10mg melatonin/kg bw; a third group was injected twice a week with B(a)P at the dose of 10mg/kg bw; the fourth group received both B(a)P and melatonin at the dose as mentioned above. The experiment continued for 3 months. In homogenates of brain, liver and kidneys lipid peroxidation was appraised by evaluation of malonyldialdehyde and 4-hydroxyalkenal (MDA+4HDA) levels. Activities of glutathione peroxidase (GPx), superoxide dysmutase (SOD) and catalase (CAT) and concentration of reduced glutathione (GSH) were also estimated. In animals receiving both B(a)P and melatonin, lower levels of MDA+4HDA were observed in all organs as compared to the group treated with B(a)P only. Following administration of B(a)P, GSH level decreased in brain and kidney. Melatonin in combination with B(a)P induced rises in the GSH level in liver and brain, as compared to the receiving B(a)P alone. The activity of SOD increased in the rats treated with melatonin alone but the highest activity was observed in rats treated with B(a)P plus melatonin. CAT activity in the melatonin-treated group increased in brain and liver. Similar to SOD, activity of the enzyme significantly increased in the group treated in combination with B(a)P and melatonin, as compared to the remaining groups in all tested tissues. The results suggest that melatonin protects cells from the damaging action of B(a)P. According to our knowledge, there are no studies describing the effects of melatonin on lipid peroxidation markers and antioxidative enzymes during intoxication of B(a)P in the brain, liver and kidneys. The results of present study give a perspective for further studies of its free radical scavenger properties in prevention of oxidative stress dependent diseases, among others cancers caused by carcinogens such as B(a)P.

Vipera berus bites in the Region of Southwest Poland--a clinical analysis of 26 cases.

OBJECTIVE Vipera berus is the only naturally occurring venomous snake in Poland. Its venom is primarily vasculotoxic and evokes both local and systemic findings. The aim of the study was to review a series of clinical cases of V berus bites occurring in southwest Poland. METHODS The charts of 26 patients (age range, 16-66 years; mean, 42 years) hospitalized with V berus bites were retrospectively analyzed using a data collection tool. Demographic and clinical data were extracted. RESULTS The most common local findings of envenomation were edema of the bitten limb with associated extravasations observed in 24 (92.3%) patients, but in only 1 (3.8%) case did the edema spread to the trunk. In 22 (84.6%) cases edema disappeared within 2 weeks after the bite. Systemic disturbances observed in the patients were: shock (1 case), mild transient hypotension (1 case), prolonged hypotension (3 cases), bronchospasm and laryngeal edema (1 case), diarrhea (1 case), transient supraventricular arrhythmias (2 cases), neutrophilic hyperleukocytosis (2 cases), and thrombocytopenia below 50000 cells/microL (5 cases). In 16 patients (61.5%) the envenomation was classified as moderate and this type was predominant. Six cases were classified as severe. No fatal case was reported. Treatment included the administration of specific antivenom in 14 cases (in all severe and half of moderate cases) and symptomatic treatment applied in all cases. CONCLUSIONS Moderate envenomation prevailed among the patients analyzed in the study. Antivenom treatment is primarily necessary in cases of severe (grade 3) and in some cases of moderate (grade 2) envenomation, especially in patients with persistent or recurring hypotension.

Influence of ezetimibe on selected parameters of oxidative stress in rat liver subjected to ischemia/reperfusion.

Introduction Ischemia/reperfusion (I/R) is considered to be one of the main causes of liver damage after transplantation. The authors evaluated the effect of ezetimibe on selected oxidative stress parameters in ischemic/reperfused (I/R) rat liver. Material and methods Rats were administered ezetimibe (5 mg/kg) (groups E and E-I/R) or saline solution (groups C and C-I/R) intragastrically for 21 days. Livers of animals in groups C-I/R and E-I/R were subjected to 60 min of partial ischemia (left lateral and median lobes) followed by 4 h of reperfusion. Alanine and asparagine aminotransferase (ALT, AST) activity was determined in blood before I/R and during reperfusion (at 15 and 240 min). After the reperfusion period, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GPx) were determined in liver homogenates using colorimetric methods. Results Ezetimibe caused a significant increase in GSH level in groups subjected to I/R (E-I/R (99.91 ±9.01) vs. C-I/R (90.51 ±8.87), p < 0.05). Additionally, under I/R the decrease of GPx activity in the drug-treated group was lower compared to the non-treated group (E-I/R (3.88 ±1.11) vs. E (5.31 ±1.83), p = 0.076). Neither ezetimibe nor I/R affected SOD or MDA levels. I/R produced a significant increase in aminotransferase levels (ALT240-0: C-I/R (42.23 ±43.56) vs. C (9.75 ±11.09), and E-I/R (39.85 ±26.53) vs. E (4.38 ±1.36), p < 0.05 in both cases; AST 240-0: E-I/R (53.87 ±17.23) vs. E (24.10 ±9.66), p < 0.05) but no effect of ezetimibe on those enzymes was found. Conclusions Ezetimibe demonstrates antioxidant properties in rat livers subjected to I/R. However, neither a hepatoprotective nor a hepatotoxic effect of ezetimibe was demonstrated, regardless of I/R.

Suicidal overdose with relapsing clomipramine concentrations due to a large gastric pharmacobezoar

The paper presents a case of fatal intoxication after massive sustained-release clomipramine overdosage with prolonged toxicity related to a large gastric pharmacobezoar. 42-year-old female was admitted to the toxicology unit 14 h after drugs ingestion. At admission patient was deeply unconscious, required controlled mechanical ventilation. Serum total level of TCAs was 1955 ng/mL. Gastric lavage revealed no pills. Within the next 12h the patients clinical condition improved. TCAs level decreased to 999 ng/mL. However, after another 10h the clinical condition started deteriorating again and the patient went into a deep coma requiring controlled mechanical ventilation. TCAs level increased to 2011 ng/mL. X-ray and computed tomography revealed large pharmacobezoar consisted from radio-opaque pills. In the 28th h of hospitalization gastrotomy was performed, confirming presence of pharmacobezoar formed from Anafranil SR tablets. After surgery TCAs level was gradually decreasing. However, the patients condition did not improve, she died 32 h after gastrotomy. Post-mortem analyses revealed drug and its metabolite toxic levels in blood (clomipramine - 1729 ng/mL, norclomipramine - 431 ng/mL) and toxic levels in internal organs: myocardium (clomipramine - 14,420 ng/g, norclomipramine - 35,930 ng/g), vitreous humor (clomipramine - 1000 ng/mL, norclomipramine - 3110 ng/mL). Described case report indicates that sustained release clomipramine tablets may form pharmacobezoar. X-ray and computed tomography examinations should be considered in cases of massive abuse of sustained release clomipramine, particularly if symptoms of intoxication are recurrent or persistent.

Effect of simvastatin treatment on rat livers subjected to ischemia/reperfusion.

We evaluated the effect of simvastatin (SV) on the oxido-redox state in rat livers submitted to ischemia-reperfusion (I/R). Rats received SV (groups: S, S-IR) or saline solution (groups: C, C-IR) intragastrically (25 mg/kg) for 21 days. Before homogenization, rat livers (C-IR, S-IR) underwent ischemia (40 min) and reperfusion (60 min). Activities of such antioxidative enzymes as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) as well as lipid peroxides (LPO) level as indicator of oxidative stress were then estimated in the homogenates. All these parameters were measured spectrophotometrically. Additionally, alanine and asparagine aminotransferase (ALT, AST) levels were estimated in the blood before and after I/R. In groups C and S all examined parameters were similar regardless of SV-treatment. I/R produced significant increases in GPx and CAT activities only in the C-IR group. Conversely, GPx activity was significantly decreased and ALT and AST increased significantly in the S-IR group. SV did not evoke any noticeable protective changes in rat livers after 3 weeks of treatment. After I/R, some of the observed properties could suggest that SV may have even made liver function and the oxidative state worse.