Cardioprotective and Hepatoprotective Potential of Silymarin in Paracetamol-Induced Oxidative Stress.

Silymarin, derived from Silybum marianum, has been used in traditional medicine for various ailments. In this study, the cardioprotective and hepatoprotective effects of silymarin against paracetamol-induced oxidative stress were examined in 28 male Swiss Webster mice, divided into four groups and treated for 7 days (via the oral route) with (a) saline 1 mL/kg (control group), (b) saline 1 mL/kg + single dose of paracetamol 110 mg/kg on the 7th day; (c) silymarin 50 mg/kg; and (d) silymarin 50 mg/kg + single dose of paracetamol 110 mg/kg on the 7th day. In vitro and in vivo antioxidant activity together with liver enzyme activity were evaluated. Histopathological and immunohistochemical assessment was performed. Silymarin mitigated paracetamol-induced liver injury by reducing oxidative stress markers such as lipid peroxidation and restoring antioxidant enzyme activity. Silymarin treatment resulted in a significant decrease in liver enzyme levels. Reduced necrosis and inflammatory infiltrate in liver tissues of silymarin-treated groups were detected as well. Immunohistochemical analysis demonstrated reduced expression of inflammatory markers (COX2, iNOS) and oxidative stress marker (SOD2) in the liver tissues of the silymarin-treated groups. Similar trends were observed in cardiac tissue. These results suggest that silymarin exerts potent hepatoprotective and cardioprotective effects against paracetamol-induced oxidative stress, making it a promising therapeutic agent for liver and heart diseases associated with oxidative damage.

Correction: Banjac et al. The Effects of Different Doses of Sildenafil on Coronary Blood Flow and Oxidative Stress in Isolated Rat Hearts. Pharmaceuticals 2023, 16, 118.

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Carob Extract (Ceratonia siliqua L.): Effects on Dyslipidemia and Obesity in a High-Fat Diet-Fed Rat Model.

Dyslipidemia and obesity are recognized as two of the major global health issues and main risk factors for coronary heart disease and cerebrovascular disease. In recent years, carob has shown certain antioxidant and anti-dyslipidemic potential. In this study, Wistar rats were fed with a standard and cholesterol-enriched diet and treated orally with carob extract and simvastatin for four weeks. After sacrifice, blood samples were collected for biochemical analysis, and liver tissue was taken for histological and immunohistochemical assessment. Weight gain was significantly higher in groups fed with cholesterol-fortified granules; total cholesterol was found to be significantly lower in the hypercholesterolemic groups treated with simvastatin and simvastatin/carob combined regimens compared with hypercholesterolemic animals treated with saline (p < 0.05). The same was true for low-density lipoprotein cholesterol and the LDL/HDL ratio (p < 0.05). Adiponectin was remarkably higher in animals treated with simvastatin compared to all other groups (p < 0.05). Leptin was significantly lower in groups treated with carob and simvastatin compared to the hypercholesterolemic group treated with saline (p < 0.05). Carob/simvastatin co-administration reduced hepatocyte damage and improved liver morphology. A study confirmed the anti-dyslipidemic, anti-obesity, and hepatoprotective potential of carob pulp alone or in combination with simvastatin in the treatment of high-fat diet-fed rats.

Can pumpkin save us of doxorubicin induced cardiotoxicity? / ¿Puede la calabaza salvarnos de la cardiotoxicidad inducida por doxorrubicina?

SUMMARY: Doxorubicin (DOX) is one of the drugs necessary for the treatment of the 10 most common types of cancer. The leading adverse effect limiting clinical use of DOX is cardiotoxicity. Given that literature data indicate a protective role of carotenoids in doxorubicin-induced toxicity, in our study we compared the cardioprotective effect of a mixture of pumpkin carotenoids and a commercially available antioxidant preparation. Animals were distributed in 8 groups (Control - S; NADES - N; Doxorubicin - Dox; Carotenoids - Car; CardiofortIN - CF; NADES-Doxorubicin - N-Dox; Carotenoids-Doxorubicin - Car-Dox; CardiofortIN-Doxorubicin - CF-Dox). Histological sections were stained with the hematoxylin-eosin (HE) and analyzed for the presence of myocardial damage by doxorubicin damage score (DDS). From the heart tissue homogenate were determined the intensity of lipid peroxidation and specific antioxidative enzyme activity (superoxide dismutase; catalase; glutathione S-transferase; glutathione peroxidase). In Car-DOX and CF-DOX groups, lipid peroxidation is significantly reduced compared to DOX group. Pretreatment of animals with carotenoids and in lesser extent with CardiofortIN led to higher antioxidative enzymes activity, compared to DOX group. Pretreated with carotenoids, only 50 % of animals had some degree of myocardial damage, and no animals had extensive damage. CardiofortIN pretreatment showed less protective effect. Pretreatment with carotenoid extract, reduced DDS significantly, so Car-DOX group has changes equivalent to mild myocardial damage. Although CardiofortIN pretreatment lowered DDS score values, animals still had moderate level of myocardium damage. This in vivo study and its findings indicate that carotenoids extracted from pumpkin may be a promising cardioprotective agent against doxorubicin induced cardiotoxicity, at least in part mediated through inhibition of DOX-induced oxidative stress.

La doxorrubicina (DOX) es uno de los fármacos necesarios para el tratamiento de los 10 tipos más comunes de cáncer. El principal efecto adverso que limita el uso clínico de DOX es la cardiotoxicidad. Debido a que los datos de la literatura indican un papel protector de los carotenoides en la toxicidad inducida por doxorrubicina, en nuestro estudio comparamos el efecto cardioprotector de una mezcla de carotenoides de calabaza y una preparación antioxidante disponible comercialmente. Los animales se distribuyeron en 8 grupos (Control - S; NADES - N; Doxorrubicina - Dox; Carotenoides - Car; CardiofortIN - CF; NADES-Doxorrubicina - N-Dox; Carotenoides-Doxorrubicina - Car-Dox; CardiofortIN- Doxorrubicina - CF-Dox). Las secciones histológicas se tiñeron con hematoxilina-eosina (HE) y se analizaron para detectar la presencia de daño miocárdico mediante la puntuación de daño por doxorrubicina (DDS). A partir del homogeneizado de tejido cardíaco se determinó la intensidad de la peroxidación lipídica y la actividad enzimática antioxidante específica (superóxido dismutasa, catalasa, glutatión S-transferasa, glutatión peroxidasa). En los grupos Car-DOX y CF-DOX, la peroxidación lipídica se redujo significativamente en comparación con el grupo DOX. El pre tratamiento de los animales con carotenoides y, en menor medida, con CardiofortlN condujo a una mayor actividad de las enzimas antioxidantes, en comparación con el grupo DOX. Al ser pre tratados con carotenoides, solo el 50 % de los animales tenían algún grado de daño miocárdico y ningún animal tenía daño extenso. El pre tratamiento con CardiofortIN mostró un efecto protector menor. El pre tratamiento con extracto de carotenoides redujo significativamente el DDS, por lo que el grupo Car-DOX mostró cambios equivalentes a un daño miocárdico leve. Aunque el pre tratamiento con CardiofortIN redujo los valores de la puntuación DDS, los animales aún tenían un nivel moderado de daño al miocardio. Este estudio in vivo y sus hallazgos indican que los carotenoides extraídos de la calabaza pueden ser un agente cardioprotector prometedor contra la cardiotoxicidad inducida por doxorrubicina, al menos en parte mediada por la inhibición del estrés oxidativo inducido por DOX.

The Effects of Different Doses of Sildenafil on Coronary Blood Flow and Oxidative Stress in Isolated Rat Hearts.

The dose-response relationship of sildenafil effects on cardiac function is not completely elucidated. The aim of this study was to assess the effects of different doses of sildenafil on coronary flow and oxidative stress in isolated rat hearts. Coronary flow and markers of oxidative stress, including nitrite outflow, and superoxide anion production in coronary effluent, were determined for isolated rat hearts. The experiments were performed during control conditions and in the presence of sildenafil (10, 20, 50, 200 nM) alone or with Nω-nitro-L-arginine monomethyl ester (L-NAME) (30 µM). Sildenafil was shown to result in a significant increase in coronary flow at lower coronary perfusion pressure (CPP) values at all administered doses, whereas, with an increase in CPP, a reduction in coronary flow was observed. An increase in nitric oxide (NO) was most pronounced in the group treated with the lowest dose of sildenafil at the highest CPP value. After the inhibition of the NO-cyclic guanosine monophosphate (cGMP) signaling (NOS) system by L-NAME, only a dose of 200 nM sildenafil was high enough to overcome the inhibition and to boost release of O2-. That effect was CPP-dependent, with statistical significance reached at 80, 100 and 120 mmHg. Our findings indicate that sildenafil causes changes in heart vasculature in a dose-dependent manner, with a shift from a vasodilatation effect to vasoconstriction with a pressure increase. The highest dose administered is capable of producing superoxide anion radicals in terms of NOS system inhibition.

Hepatoprotective Effect of Carob Pulp Flour (Ceratonia siliqua L.) Extract Obtained by Optimized Microwave-Assisted Extraction.

To examine antioxidant capacity and the hepatoprotective effect of carob pulp flour, microwave-assisted extraction was performed. The influence of ethanol concentration (0-40% w/w), extraction time (5-25 min) and irradiation power (400-800 W) on DPPH, FRAP and ABTS antioxidant activity of carob pulp flour extract was evaluated. The strongest influence was that of the ethanol concentration, followed by extraction time. Optimal process parameters for maximizing total antioxidant activity were determined, using response surface methodology: ethanol concentration 40%, time 25 min and power 800 W. Carob extract obtained at optimal conditions (CE) was analyzed in vivo using a paracetamol-induced hepatotoxicity model in mice. Treatment with CE attenuated the parameters of liver injury, especially aspartate and alanine aminotransferase activity, and prevented paracetamol-induced increase in malondialdehyde levels. Pretreatment with CE reversed the activities of superoxide dismutase, catalase, glutathione peroxidase and glutathione S-transferase enzymes after the high dose of paracetamol in the liver. Hepatotoxicity induced using a toxic dose of paracetamol was also seen through histopathological alterations, which were significantly reduced in the groups treated with CE prior to paracetamol. Still, the number of Kupffer cells and macrophages did not differ among groups. Finally, pretreatment of mice with CE and paracetamol significantly decreased the expression of cytochrome P450 2E1 (CYP2E1) in hepatocytes.

Binary polymeric amorphous carvedilol solid dispersions: In vitro and in vivo characterization.

Binary polymeric amorphous carvedilol solid dispersions were prepared using solvent method by varying solvent type, polymer type and carvedilol to polymer ratio in order to assess the influence of these factors and maximize carvedilol dissolution rate. Low and high molecular weight polyvinylpyrrolidone, polyvinylpyrrolidone-vinyl acetate copolymer and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer were used as polymeric carriers in carvedilol to polymer ratios 1:1, 1:2 or 1:4, while absolute ethanol or acetone were used as solvents. Hard gelatin capsules were prepared with carvedilol solid dispersion and lactose monohydrate, mannitol or microcrystalline cellulose. FTIR and PXRD were used to detect carvedilol crystallinity and identify carvedilol-polymer interactions and carvedilol polymorphs. These techniques confirmed carvedilol transition to amorphous state and suggested that hydrogen bonds were formed between carvedilol and polymer molecules. Carvedilol dissolution rate was significantly higher from solid dispersions with higher carvedilol to polymer ratio and solid dispersions prepared using the solvent in which the polymer was more soluble. Solid dispersion with polyvinylpyrrolidone-vinyl acetate copolymer in 1:4 ratio in absolute ethanol displayed the highest carvedilol dissolution rate with 91.78% carvedilol dissolved in the first 30 min. Capsules prepared with the selected solid dispersion and microcrystalline cellulose as diluent displayed the highest carvedilol dissolution rate, with 93.43% carvedilol dissolved within the first 30 min. Carvedilol bioavailability was significantly increased by formulating solid dispersions, while the analysis of serum biochemical parameters excluded damage on liver and kidney function and the lipid profile of animals exposed to investigated drug delivery system.

Antioxidative and Protective Actions of Apigenin in a Paracetamol-Induced Hepatotoxicity Rat Model.

BACKGROUND AND OBJECTIVES: Apigenin is known to have various pharmacological properties without causing significant toxicity; however, hepatoprotective effect of apigenin is not often reported. The aim of our study was to investigate if the alterations in lipid peroxidation and antioxidant status are in favor to prove the efficacy of apigenin against paracetamol-induced hepatotoxicity. METHODS: The effect of apigenin on paracetamol-induced hepatotoxicity in rats was examined by determining biochemical parameters, histological assessment and oxidative status in liver homogenates. RESULTS: The treatment of animals with both apigenin and paracetamol attenuates the parameters of hepatotoxicity, especially for ALT and ALP activity which was significantly lower compared to groups of animals treated with saline and paracetamol. Hepatotoxicity induced by toxic dose of paracetamol was revealed also by notable histopathological alterations, which were not observed in the group treated with paracetamol together with apigenin. Apigenin also prevented paracetamol-induced increase in malondialdehyde (MDA) level. The activities of both CAT (catalase) and GR (glutathione reductase) enzymes after the toxic dose of paracetamol were significantly increased in the liver homogenates, compared to control group. Apigenin reversed these parameters near to values of control group. CONCLUSIONS: The result of our study indicates that apigenin inhibits the level of lipid peroxidation and significantly increases the enzyme antioxidant defense mechanisms in paracetamol-induced hepatotoxicity in rats.