Optimization and Kinetic Modelling of Total Phenols and Flavonoids Extraction from Tilia cordata M. Flowers

The main goal was to optimize and establish the kinetics and the thermodynamics of the extraction process. An investigation into the effects of ethanol  concentration (0–100 %), liquid to solid ratio (30–60 mL g–1), extraction temperature (25–65 °C), and extraction time (40–200 min) on the extraction of total  phenols (TP) and total flavonoids (TF) from linden (Tilia cordata M.) flowers was performed using single-factor experiments. Experimental results  showed that extraction conditions had a significant effect on the extraction of phenolic compounds. The optimized conditions were 50 % ethanol, liquid  to solid ratio 60 mL g–1 for 120 min at 55 °C, with values of 17.05 mg GAE g–1 dry weight (d.w.) for TP and 13.32 mg CE g–1 d.w. for TF. Extracted phenolic  compounds were analyzed by HPLC. The antioxidant activity of the extracts was evaluated by DPPH and ABTS assays. The applicability of different  mathematical models (model based for the unsteady diffusion through the plant material, model based on the film theory and model of Ponomaryov) to  describe the kinetics of the extraction process of TP and TF from linden flowers was studied as well. The mathematical models applied showed a good  agreement with the experimental results, which allows their application in modelling and optimizing the solid/liquid extraction process to extract TP and  TF from linden flowers.&nbsp

FOLLOW-UP OF BIOCHEMICAL PARAMETERS AND INTENSITY OF OXIDATIVE STRESS IN PATIENTS WITH EXTRAHEPATHIC CHOLESTASIS

In cholestasis, due to impossibility of gall flow into duodenum, there occurs a subsequent return of gall constituents to hepatocytes and circulation. Extrahepatic cholestasis is the result of mechanic obstacle of gall flow through ductus hepaticus, choledochus or papilla Vateri, leading to the occurrence of manifest icterus. In cases leading to liver damage, hydrophobic gall salts and non-conjugated bilirubins have the most important toxic effects.The aim of this study was to follow up the biochemical parameters, enzyme activity AST, ALT, *-GT and AF, bilirubin concentration and albumins, and intensity of oxidative stress in blood plasma in patients with different types of extrahepatic cholestasis.The study included 60 subjects divided into two groups. The first one was control group (30 healthy subjects), while II group involved 30 patients with intraluminar extrahepatic obstruction.Significant increase of enzyme activity of AST, ALT, *-GT and AF in plasma of cholestatic patients was present in comparison to the control group (p< 0,001). The levels of total direct and indirect bilirubin in plasma of cholestatic patients increased (p<0,001) when compared to the control group. The level of albumin in plasma of cholestatic patients significantly decreased in comparison to the control group (p<0,05). The intensity of oxidative stress measured through the levels of malondialdehide (MDA) and carbonyl group concentration in plasma of cholestatic patients increased (p<0,001) when compared to the control group.Significant increase of cholestasis enzyme markers (AST, ALT, *-GT and AF) and bilirubin levels in blood plasma was noticed in patients with extrahepatic cholestasis. Cholestasis leads to significant disorders of synthetic function of the liver that are manifested by decrease of albumin concentration in plasma

Kinetika ekstrakcije vanilinske kiseline iz semena bundeve

In this sdudy, the extraction of vanillic acid from pumpkin seeds, using the maceration process, were investigated. The influence of temperature (25-45oC) and time (10-100 min) on the content of vanillic acid in extracts was confirmed. Based on the experimental results of the extraction of kinetics, a modeling of pumpkin seeds-40% ethanol (v/v) extraction system was performed using hyperbolic model. Also, based on the average values of the RMS, SD and R2, it was found that the hyperbolic model show acceptable agreement.U ovom radu proučena je ekstrakcija vanilinske kiseline iz semena bundeve primenom postupka meceracije. Ispitan je uticaj temperature (25-45oC) i vremena (10-100 min) ekstrakcije na sadržaj vanilinske kiseline u ekstraktima. Na osnovu eksperimentalnih rezultata kinetike ekstrakcije izvešeno je modelovanje ekstrakcionog sistema seme bundeve-40% etanol (v/v) primenom hiperbolnog modela. Takođe, na osnovu srednjih vrednosti RMS, SD i R2 modelovanih i eksperimentalnih vrednosti sadržaja vanilinske kiseline, utvrđeno je da hiperbolni model pokazuje prihvatljivo slaganje

The Encapsulation of Lycopene in Nanoliposomes Enhances Its Protective Potential in Methotrexate-Induced Kidney Injury Model

Methotrexate is an antimetabolic drug with a myriad of serious side effects including nephrotoxicity, which presumably occurs due to oxidative tissue damage. Here, we evaluated the potential protective effect of lycopene, a potent antioxidant carotenoid, given in two different pharmaceutical forms in methotrexate-induced kidney damage in rats. Serum biochemical (urea and creatinine) and tissue oxidative damage markers and histopathological kidney changes were evaluated after systemic administration of both lycopene dissolved in corn oil and lycopene encapsulated in nanoliposomes. Similar to previous studies, single dose of methotrexate induced severe functional and morphological alterations of kidneys with cell desquamation, tubular vacuolation, and focal necrosis, which were followed by serum urea and creatinine increase and disturbances of tissue antioxidant status. Application of both forms of lycopene concomitantly with methotrexate ameliorated changes in serum urea and creatinine and oxidative damage markers and markedly reversed structural changes of kidney tissue. Moreover, animals that received lycopene in nanoliposome-encapsulated form showed higher degree of recovery than those treated with free lycopene form. The findings of this study indicate that treatment with nanoliposome-encapsulated lycopene comparing to lycopene in standard vehicle has an advantage as it more efficiently reduces methotrexate-induced kidney dysfunction

Uv light impact on phthalates migration from children's toys into artificial saliva

Phthalates has been widely used in children?s toys as plastic plasticizers and softeners. Therefore, attention should be paid to plastic toys, especially those that children can put in their mouths. In this paper quantification of five phthalates: DMP, DnBP, BBP, DEHP and DnOP in plastic toys, as well as irradiation of toys with UV light was performed. After sample preparation and development of the liquid?liquid phthalate extraction method from artificial saliva phthalate quantitative determination using the GC?MS technique was performed. The mean recovery value for DEHP is 77.03?2.76 %. The determination of phthalate in the recipient models (artificial saliva and n-hexane) was performed after 6, 15 and 30 days of the migration test using the GC?MS technique. Based on the known mass % DEHP in the analyzed toys, the percentage of phthalate migration from each analyzed toy to the recipient model after 6, 15 and 30 days of the migration test was calculated. The results show that there is no significant migration of DEHP into artificial saliva, due to high polarity of the recipient (artificial saliva is polar), unlike n-hexane where the migration of DEHP is significant because it is a non-polar solvent

Malondialdehyde as an independent predictor of body mass index in adolescent girls

Background: Given the fact that the studies that examined oxidative stress in relation to obesity that included late adolescents are scarce and show inconclusive results we aimed to investigate a wide spectrum of nitro-oxidative stress biomarkers i.e., malondialdehyde (MDA), xanthine oxidase (XO), xanthine oxidoreductase (XOD), xanthine dehydrogenase (XDH), advanced oxidation protein products (AOPP) and nitric oxide products (NOx), as well as an antioxidative enzyme, i.e., catalase (CAT) in relation with obesity in the cohort of adolescent girls ages between 16 and 19 years old. Methods: A total of 59 teenage girls were included in this cross-sectional study. Binary logistic regression analysis was performed to examine possible associations between biochemical and nitro-oxidative stress markers and body mass index (BMI). Results: There were not significant differences between oxidative stress markers between normal weight and overweight/obese girls (i.e., AOPP, XOD, XO, XDH) and CAT, except for MDA (p<0.001) and NOx (p=0.010) concentrations which were significantly higher in overweight/obese adolescent girls. Positive associations were evident between BMI and high sensitivity C-reactive protein (hsCRP) (OR=2.495), BMI and uric acid (OR=1.024) and BMI and MDA (OR=1.062). Multivariable binary regression analysis demonstrated significant independent associations of BMI and hsCRP (OR=2.150) and BMI and MDA (OR=1.105). Even 76.3% of the variation in BMI could be explained with this Model. Conclusions: Inflammation (as measured with hsCRP) and oxidative stress (as determined with MDA) independently correlated with BMI in teenage girls

ANTIOXIDANTS AND THEIR IMPORTANCE DURING MUSCULAR EXERCISE: A REVIEW

Physiological levels of reactive oxygen species, as an essential part of the homeostatic milieu, are required for normal functioning of skeletal muscle. High levels of reactive oxygen species promote contractile dysfunction resulting in muscle weakness and fatigue, oxidative stress, apoptosis and necrosis of muscle cells. It is known that both resting and contracting skeletal muscles produce reactive oxygen species and reactive nitrogen species. The first suggestion that physical exercise results in free radical-mediated damage to tissues appeared in 1978. The newest researches investigate the mechanisms by which oxidants influence skeletal muscle contractile properties and explore how to protect muscle from oxidant-mediated dysfunction. Principal antioxidant enzymes include superoxide dismutase, glutathione peroxidase, and catalase. Numerous non-enzymatic antioxidants exist in cells within skeletal muscle fibers, the most abundant of which include glutathione, bilirubin, α-Lipoic acid , uric acid, and ubiquinones, or coenzyme Q (CoQ) andflavonoids. Dietary antioxidants are vitamins C- L ascorbic acid , vitamin A, retinol and their provitamins, carotenoids (especially β-carotene), vitamins E, tocopherol (especially a-tocoferol ), folic acid or folates. The usage of endogenous enzymatic and non-enzymatic antioxidants protects muscle from strong damaging effects caused by free radicals during acute exercise or longer term physical exercise. Scientific researches now confirm that the long-term use of antioxidants is safe and effective. The actual recommendation for physically active individuals is to ingest a diet rich in antioxidants

SKIP is required for TGF-beta 1-induced epithelial mesenchymal transition and migration in transformed keratinocytes

Transforming growth factor-beta 1 (TGF-beta 1) potently induces the epithelial-mesenchymal transition (EMT) during tumoral progression. Although Sky-interacting protein (SKIP) regulates TGF-beta 1-induced Smad activation, its role in the induction of cell malignance remains uncertain. We found that TGF-beta 1 increases SKIP expression in PDV cells. In cells stably transfected with SKIP antisense, AS-S, Smad3 activation decreased, along with an inhibition of TGF-beta 1-induced EMT, and the cells were sensitized to the TGF-beta 1-dependent inhibition of proliferation. Also, AS-S cells showed a weaker migration and invasion response. Moreover, TGF-beta 1-induced urokinase-type plasminogen activator expression was inhibited, concomitantly with a TGF-beta 1-independent increment of the plasminogen-activator inhibitor-1 expression. Thus, these results suggest that SKIP is required for EMT and invasiveness induced by TGF-beta 1 in transformed cells