Effects of melatonin on Wi-Fi-induced oxidative stress in lens of rats

Introduction:

Melatonin has been considered a potent antioxidant that detoxifies a variety of reactive oxygen species in many pathophysiological states of eye. The present study was designed to determine the effects of Wi-Fi exposure on the lens oxidant, antioxidant redox systems, as well as the possible protective effects of melatonin on the lens injury induced by electromagnetic radiation (EMR).

Materials and Methods:

Thirty-two rats were used in the current study and they were randomly divided into four equal groups as follows: First and second groups were cage-control and sham-control rats. Rats in third group were exposed to Wi-Fi (2.45 GHz) for duration of 60 min/day for 30 days. As in the third group, the fourth group was treated with melatonin. The one-hour exposure to irradiation in second, third and fourth took place at noon each day.

Results:

Lipid peroxidation levels in the lens were slightly higher in third (Wi-Fi) group than in cage and sham control groups although their concentrations were significantly (P < 0.05) decreased by melatonin supplementation. Glutathione peroxidase (GSH-Px) activity was significantly (P < 0.05) lower in Wi-Fi group than in cage and sham control groups although GSH-Px (P < 0.01) and reduced glutathione (P < 0.05) values were significantly higher in Wi-Fi + melatonin group than in Wi-Fi group.

Conclusions:

There are poor oxidative toxic effects of one hour of Wi-Fi exposure on the lens in the animals. However, melatonin supplementation in the lens seems to have protective effects on the oxidant system by modulation of GSH-Px activity.     

Four novel and two recurrent NHLRC1 (EPM2B) and EPM2A gene mutations leading to Lafora disease in six Turkish families

Lafora disease (LD) is a type of autosomal recessive, progressive myoclonus epilepsy resulting mostly from mutations in the EPM2A and NHLRC1 genes. Mutational analysis in both genes was initiated with the aim of establishing LD DNA diagnosis in Turkey. Four novel NHLRC1 (p.G131X, p.P69S and p.D82H) and EPM2A (p.V7A) and two recurrent NHLRC1 (p.D146N) and EPM2A (p.R241X) mutations were identified in six families. The delineation of causative mutations in patients provided early disease diagnosis for other family members and contributed to the knowledge of LD pathogenesis.     

Ligand based pharmacophore model development for the identification of novel antiepileptic compound

Epilepsy is a common neurological disorder throughout the world which is characterized by recurrent unprovoked epileptic seizures. A need exists for the development of new antiseizure drugs with improved efficacy and tolerability, as several of the currently available antiepileptic drugs (AEDs) have been associated with severe side effects. A ligand based pharmacophore approach has been generated for 44 new antiepileptic compounds with emphasis on the development of new drugs by using LigandScout software and distance estimation using Jmol. The pharmacophore of the compounds contained three features hydrophobic unit, hydrogen bonding domain and electron donor. The pharmacophore models derived were then filtered using the Lipinski's rule of five criteria and orally bio-available compounds were obtained. Thus, this approach was able to reclaim few leads which had projected inhibitory activity alike to most active compounds with suitable calculated drug-like properties and therefore they could be recommended for further studies.     

Mitochondrial oxidative stress-induced brain and hippocampus apoptosis decrease through modulation of caspase activity,Ca2+ influx and inflammatory cytokine molecular pathways in the docetaxel-treated mice by melatonin and selenium treatments

Docetaxel (DOCE) is widely used to treat several types of glioblastoma. Adverse effects DOCE seriously limit its clinical use in several tissues. Its side effects on brain cortex and hippocampus have not been clarified yet. Limited data indicated a protective effect of melatonin (MLT) and selenium (SELEN) on DOCE-induced apoptosis, Ca²⁺ influx and mitochondrial reactive oxygen species (ROS) in several tissues except brain and hippocampus. The purpose of this study is to discover the protective effect of MLT and SELEN on DOCE-induced brain and hippocampus oxidative toxicity in mice. MLT and SELEN pretreatments significantly ameliorated acute DOCE-induced mitochondrial ROS production in the hippocampus and brain tissues by reducing levels of lipid peroxidation, intracellular ROS production and mitochondrial membrane depolarization, while increasing levels of total antioxidant status, glutathione, glutathione peroxidase, MLT, α-tocopherol, γ-tocopherol, vitamin A, vitamin C and β-carotene in the tissues. Furthermore, MLT and SELEN pretreatments increased cell viability and TRPM2 channel activation in the hippocampus and brain followed by decreased activations of TNF-α, IL-1β, IL-6, and caspase ?3 and???9, suggesting a suppression of calcium ion influx, apoptosis and inflammation responses. However, modulator role of SELEN on the values in the tissues is more significant than in the MLT treatment. MLT and SELEN prevent DOCE-induced hippocampus and brain injury by inhibiting mitochondrial ROS and cellular apoptosis through regulating caspase ?3 and???9 activation signaling pathways. MLT and SELEN may serve as potential therapeutic targets against DOCE-induced toxicity in the hippocampus and brain.

     

Patterns of recognition of Arabic consonants by non-native children with cochlear implants and normal hearing

Objective: This study examined the patterns of recognition of Arabic consonants, via information transmission analysis for phonological features, in a group of Malay children with normal hearing (NH) and cochlear implants (CI).

Method: A total of 336 and 616 acoustic tokens were collected from six CI and 11 NH Malay children, respectively. The groups were matched for hearing age and duration of exposure to Arabic sounds. All the 28 Arabic consonants in the form of consonant–vowel /a/ were presented randomly twice via a loudspeaker at approximately 65?dB SPL. The participants were asked to repeat verbally the stimulus heard in each presentation.

Results: Within the native Malay perceptual space, the two groups responded differently to the Arabic consonants. The dispersed uncategorized assimilation in the CI group was distinct in the confusion matrix (CM), as compared to the NH children. Consonants /?/, /t?/, /s?/ and /?/ were difficult for the CI children, while the most accurate item was /k/ (84%). The CI group transmitted significantly reduced information, especially for place feature transmission, then the NH group (p?Conclusion: CI and NH Malay children may be using different acoustic cues to recognize Arabic sounds, which contribute to the different assimilation categories’ patterns within the Malay perceptual space.