Electrochemical screening of genoprotective and antioxidative effectiveness of Origanum vulgare L. and its functionality in the prevention of neurodegenerative disorders.

A new way of electrochemical DNA sensor using as a screening tool for the determination of phytochemicals with high genoprotective functionality is proposed. The biosensor's detection layer was prepared with double stranded deoxyribonucleic acid (ds DNA) that were subjected to oxidative stress induced by •OH radicals generated by Fenton reaction. The oxidized guanine derivative, 8-oxo-7,8-dihydro-2'-deoxyguanosine, was treated as an indicator of DNA oxidative damage. This derivative may cause mutation through its ability to pair with adenine. The abnormalities of DNA structure and DNA repair system are known to be directly related to progressive neurodegeneration. The present study showed that during oxidative stress, the 2.5% oregano extract protected guanine from undergoing oxidation to 8-oxoguanine. The results revealed that this genoprotective effectiveness can make oregano a very efficient protective barrier against oxidative stress. Due to these unique properties of oregano we propose the recipe of a functional bread with its addition. It was found that the functionality of the prepared bread was not limited to antioxidative activity but also is expressed in the inhibition of cholinesterases. These findings indicate that oregano can act as an important component in the therapeutic diet recommended in neurodegenerative disorders.

How taste works: cells, receptors and gustatory perception.

The sensitivity of taste in mammals varies due to quantitative and qualitative differences in the structure of the taste perception organs. Gustatory perception is made possible by the peripheral chemosensory organs, i.e., the taste buds, which are distributed in the epithelium of the taste papillae of the palate, tongue, epiglottis, throat and larynx. Each taste bud consists of a community of ~100 cells that process and integrate taste information with metabolic needs. Mammalian taste buds are contained in circumvallate, fungiform and foliate papillae and react to sweet, salty, sour, bitter and umami stimuli. The sensitivity of the taste buds for individual taste stimuli varies extensively and depends on the type of papillae and the part of the oral cavity in which they are located. There are at least three different cell types found in mammalian taste buds: type I cells, receptor (type II) cells and presynaptic (type III) cells. This review focuses on the biophysiological mechanisms of action of the various taste stimuli in humans. Currently, the best-characterized proteins are the receptors (GPCR). In addition, the activation of bitter, sweet and umami tastes are relatively well known, but the activation of salty and sour tastes has yet to be clearly explained.