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Formation of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) was examined to evaluate the impact of using vegetable oil as fat replacement on carcinogen formation in meat product. Pork patties were formulated with 40% fat replacement by olive oil, sunflower oil or grape seed oil, respectively and cooked at 180 °C or 220 °C. Control patties contained the highest amount of HCAs compared with all other patties at both temperatures. Olive oil and sunflower oil replacement completely inhibited formation of MeIQ (2-amino-3, 4-dimethylimidazo[4,5-f]quinoline), while grape seed oil completely inhibited MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine) in patties. Grape seed oil achieved the highest inhibition capacity compared with sunflower oil and olive oil. HCAs increased significantly with cooking temperature (p < 0.05), but no difference was observed in total PAHs for patties cooked at different temperature (p > 0.05). In conclusion, fat replacement with sunflower oil, olive oil or grape seed oil in pork patties could reduce the formation of HCAs without compromising eating quality. [ABSTRACT FROM AUTHOR]

An inflammatory reaction occurs following biomaterial implantation in the body, which produce toxic byproducts such as reactive oxygen species (ROS). Although ROS is required to clear the wound, excessive ROS can damage the tissue around the implant site, eventually leading to implant failure. One approach to control the inflammatory response is to incorporate an antioxidant into the biomaterial in order to scavenge ROS produced by activated phagocytes. In the present study, an organoselenium antioxidative compound was incorporated into a brushite cement, with the goal of scavenging ROS generated from activated primary human mononuclear leukocytes (MNCs), in vitro . The effect of the antioxidant on the physical properties of brushite cement, and its release from the cement were investigated via compressive strength, setting time, phase composition, and UV spectroscopy analysis. The physical properties of brushite remained unchanged following incorporation of the antioxidant. The antioxidant was slowly released from the cement, following a non-Fickian transport mechanism, with approximately 60% of the loaded antioxidant released over five days. The released antioxidant was then tested for its ability to scavenge ROS released by MNCs using the luminol amplified chemiluminescence assay. The results show that antioxidative released at both early stages (24 h) and late stages (120 h) retained its scavenging capacity and effectively reduced ROS production. These results indicate that brushite cements loaded with organoselenium compounds can modulate ROS production after implantation and potentially modulate the inflammatory response to improve device integration. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the effect of salinity stress on growth of Cassia italica and role of gamma amminobutyric acid (GABA) in mitigating the salt stress induced damaging effects. Antioxidant activity, level of endogenous growth hormones and other biochemical parameters were evaluated. Salt stress enhanced the production of reactive oxygen species (ROS) resulting in the enhanced lipid peroxidation which was however reduced by application of GABA. Increased lipid peroxidation in salt stressed plants caused an obvious reduction in the total lipid content as compared to GABA treated plants. The antioxidant enzymes were higher in GABA treated plants which indicated a reduction of oxidative damage. The concentrations of growth hormones like indole acetic acid (IAA), indole butyric acid (IBA), gibberellic acid-1 (GA1), and gibberellic acid-4 (GA4) were reduced by salt stress, while enhanced by GABA treatment. In addition GABA treated plants maintained lower levels of sodium and chloride ions as compared to salt stressed plants. It could be concluded that toxic effects of salt stress on growth, antioxidant system, hormones and mineral nutrients in Cassia italica could be alleviated by exogenous application of GABA. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate the efficiency of treating plant tissue with enzymatic agent ViscoStar 150L for the extraction of biologically active compounds. In the current study the screening of extraction methods from citrus fruit peels (grapefruit, lemon, orange) was performed. The samples treated with enzymatic agent ViscoStar 150L showed better extraction results than the traditional ethanol/water extraction method. Citrus peels' extracts assayed for antioxidant activity (determined as ferric reducing antioxidant power -- FRAP) decreased in the following order: grapefruit > orange > lemon. The enzymatic agent ViscoStar 150L proved to have a positive synergic effect on juice yield from cowberry previously treated with a complex pectolytic enzymatic agent. The enzymatic agent ViscoStar 150L proved to have a synergic effect on grain grist mashes previously treated with an amylolytic enzymatic agent, the inhibitor activity of the compounds produced by actinomycetic microorganisms grown on substrates based on these mashes being higher than that of previously known inhibitors. [ABSTRACT FROM AUTHOR]

Antioxidants are of primary value biologically since they restrict the damage that reactive free radicals can do to cells and cellular components. These reactive free radicals are produced in cells and tissues in various ways, e.g., by the impact of radiation, by the transition metal catalysis and by redox processes often involving enzymes. In many cases, a reactive free radical arises as a result of a metabolic process within a cell, which is called metabolic activation and is of considerable significance with respect to the mechanism of action of some chemical carcinogens. [ABSTRACT FROM AUTHOR]

Abstract: Polysaccharides from Camellia oleifera leaves were extracted by ultrasonic-assisted extraction and optimized with response surface methodology. The optimal conditions of the extraction of polysaccharides were determined to be the extraction time of 1.6h, extraction temperature of 88°C and ratio of liquid to raw material of 20, which contributed to the highest yield of 3.77%. The crude polysaccharide was purified and three fractions (CLP-1, CLP-2 and CLP-3) were obtained. Their physicochemical properties were investigated with chemical method. The results indicated that the uronic acid content of CLP-2 was significantly higher than those of CLP-1 and CLP-3, and CLPs were mainly composed of glucose and galactose residue. In vitro antioxidant assay indicated that three polysaccharide fractions showed remarkable antioxidant activities in a concentration-dependent manner. Compared with CLP-1 and CLP-2, CLP-3 exhibited higher iron chelating activity. CLP-2 possessed significant higher hydroxyl radial and 2,2-diphenyl-1-picrydrazy (DPPH) radical scavenging activities than those of CLP-1 and CLP-3. Overall, the polysaccharides derived from C. oleifera leaves might be explored as potential natural antioxidant. [Copyright &y& Elsevier]

Human immunodeficiency virus (HIV) particles that remain in the blood of patients are frequently ignored as targets for AIDS treatment. We therefore investigated the use of photodynamic therapy (PDT) with hematoporphyrin monomethyl ether (HMME) as a means of inactivating cell-free HIV in vitro. Virus particles including HIV-1, resistant HIV-1 variants, HIV-1 clinical variants, and HIV-2 variants were incubated with HMME for 40 min, followed by irradiation with a 630-nm semiconductor laser at an energy density of 0.3 J/cm. The antiviral effects were evaluated by counting syncytium formation or measuring p24 antigen expression levels in supernatants by enzyme-linked immunosorbent assay. The relationships between photoinactivation and HMME concentrations, energy density, power density and antioxidants (NaN and d-mannitol) were also assessed using the above methods. All the tested virus particles were completely responsive to HMME-PDT. HMME concentration and energy density were positively correlated with photoinactivation of HIV, while power density was negatively correlated. Both sodium azide and d-mannitol weakened the inhibitory effect of PDT on virus-induced membrane fusion, with d-mannitol having a stronger effect. HMME-PDT can inactivate HIV particles, and may therefore represent a promising treatment for AIDS patients. [ABSTRACT FROM AUTHOR]

This exercise is intended to introduce undergraduate biochemistry students to the analysis of antioxidants as a biotechnological tool. In addition, some statistical resources will also be used and discussed. Antioxidants play an important metabolic role, preventing oxidative stress-mediated cell and tissue injury. Knowing the antioxidant content of nutritional components can help make informed decisions about diet design, and increase the commercial value of antioxidant-rich natural products. As a reliable and convenient technique to evaluate the whole spectrum of antioxidants present in biological samples is lacking, the general consensus is to use more than one technique. We have chosen two widely used and inexpensive methods, Trolox-equivalent antioxidant capacity and the ferric reducing antioxidant power assays, to evaluate the antioxidant content of several fruits, and to compare and analyze the correlation between both assays. © 2012 by The International Union of Biochemistry and Molecular Biology [ABSTRACT FROM AUTHOR]

Total phenolic content, total antioxidant activity of Myrobalan plum ( Prunus cerasifera Ehrh.) and anthocyanin content in peel were analyzed in this article. In addition, ultra-performance liquid chromatography with photodiode array detection and electrospray ionization tandem mass spectrometry were used to determine anthocyanin composition of this fruit. The range of total phenolic content of the tested samples was 1.34 to 6.11 g/kg fresh weight (FW), and anthocyanin content in fruit peel of Myrobalan plum was from 1.93 to 19.86 g/kg peel. Ferric reducing antioxidant power values varied from 11.20 to 44.83 μmol Trolox equivalent/g FW. Four main kinds of anthocyanins in purple Myrobalan plum were detected while 6 kinds in red ones. Practical Application: The article showed the anthocyanin composition, phenolic content, and antioxidant activities of wild Myrobalan plum. The purple Myrobalan plum could be developed as a resource of fruit drinks because of its high antioxidant activity and the peel could be used as the resource to extract natural pigments. [ABSTRACT FROM AUTHOR]