mohammad reza ashrafi-kooshk

Excessive exposure to the sources of fluoride in drinking water, oral care products, and food is a widespread problem. Fluoride is associated with impairment in child intelligence development. It causes DNA damage, oxidative stress, and mitochondrial dysfunction, mainly due to the production of reactive oxygen species (ROS). It has been postulated that the use of antioxidants such as astaxanthin, may alleviate fluoride’s adverse effects. This study assessed the effects of fluoride on cellular ROS content and rat’s learning and memory ability and investigated the protective potency of astaxanthin with emphasis on the role of glutamate using the Morris Water Maze test, glutamate concentration determination, and western blot techniques. The fluoride treatment of cells results in an increment of cellular ROS, whereas astaxanthin inhibits lipid peroxidation. Fluoride significantly decreases the cellular glutamate uptake and glutamate transporter, protein level, possibly due to the disruption of mitochondrial energy metabolism and defect of the transporter recycle, respectively. The in-vivo study indicated that the treatment of rats with fluoride led to a loss of learning, while astaxanthin improved memory dysfunction. Measurement of ROS and glutamate levels of rat brain hippocampus showed that fluoride increased the ROS but decreased the glutamate. On the other hand, the utilization of astaxanthin decreased the brain ROS content and increased the glutamate level. It seems that fluoride disrupts the normal function of neurons via increment of ROS production and decrement of glutamate level, whereas astaxanthin has neuroprotective potency due to the ROS scavenging ability.

Aldehyde oxidase, a molybdenum cofactor-containing cytosolic enzyme, is extensively distributed throughout the animal kingdom. The enzyme is mainly active in liver and other tissues of mammalian species and involved in the metabolism of wide range of aldehydes and nitrogen-containing molecules. A continuous spectrophotometric method for the quantitative determination of aldehyde oxidase, AO, enzyme activity is described in this article. This method is based on the coupling reaction between 3-methyl-2-benzothiazolinone hydrazone (MBTH) and the o-quinone. Dopamine as substrate for AO, is converted/oxidized to o-quinone. The latter react with MBTH to produce intensely colored products that absorb light maximally in the visible region. Then, AO activity has been kinetically characterized; the Km (Michaelis–Menten constant) and Vmax (maximum initial velocity) values for the oxidation of dopamine by AO were evaluated. The existence of MBTH in the reaction medium and production of stable color as well as the high ϵ values at 510 nm of MBTH-Q adduct make this direct technique more sensitive than other continuous methods for AO assay. The optimized MBTH reaction may be useful for biological staining of AO activity isolated from various biological sources in electrophoresis gels.

Allura red (AR) is a widely used colorant in food industry, but there is debate on its potential security risk. In this study, in vitro inhibitory properties of the dye against carbonic anhydrase (CA) were evaluated. The esterase activity of purified CA decreased in the presence of AR, in a dose-dependent manner. Regarding literature review and observed results, this preliminary study may provide new horizons in safety of AR and the other dye additives.

Timolol is a non-selective beta-adrenergic receptor antagonist administered for treating glaucoma, heart attacks and hypertension. In the present study, we set out to determine whether or not timolol can provoke cataract formation, thus the influence of timolol on the amyloid-type aggregation of crystallin was investigated. We then provided experimental evidence of crystallin aggregation and its induction by timolol using different spectroscopic measurements. Turbidimetric measurements as well as ThT fluorescence data indicated that timolol induce extent of crystallin amyloid formation. The kinetic of protein aggregation was also changed in presence of increasing concentrations of the drug suggesting that long-term drug administration may contribute to the development of cataract. Since the consequence of timolol-crystallin interaction has yet to be identified, additional data on it may help us to postpone amyloid cataract formation.

Curcumin is a natural polyphenolic compound with anti-cancer, anti-inflammatory, and anti-oxidation properties. Low water solubility and rapid hydrolytic degradation are two challenges limiting use of curcumin as therapeutic agent. In the current study, the role of the Bovine Serum Albumin (BSA), β-lactoglobulin and casein, as food-grade biopolymers and safe drug delivery systems, on the physical activity of curcumin were surveyed. It appears that BSA and casein as protein vehicles are useful tools to increase stability of curcumin, as a health promoting agent.

Curcumin is a natural polyphenolic compound with anti-cancer, anti-inflammatory, and anti-oxidation properties. Low water solubility and rapid hydrolytic degradation are two challenges limiting use of curcumin as therapeutic agent. In the current study, the role of the native/modified forms of bovine serum albumin (BSA) and casein, as food-grade biopolymers and safe drug delivery systems, on the physical and biological activity of curcumin were surveyed. Analyses of quenching of proteins fluorescence by curcumin indicated that chemical modification decreased binding affinity of curcumin toward albumin whereas it significantly increased for casein and average number of binding sites also doubled in modified casein. Measurement of cell viability using LDH assay showed that cytotoxicity of protein-bound curcumin is higher than free curcumin. Moreover, in the presence of native proteins, curcumin revealed elevated in vitro anti-cancer activity (against MCF7 and SKNMC) compared to modified forms. It appears that BSA and casein as protein vehicles are useful tools to increase both food quality and the bioavailability of curcumin as health promoting agent. However, results imply that the chemical modification of proteins cannot improve the anti-cancer activity of curcumin despite increasing of their binding affinity.