Abstract
The skin is the largest organ in the body and is consistently exposed to aggressive environmental attacks (biological/physical/chemical, etc.). Reactive oxygen species (ROS) are formed during the normal oxidative metabolism which enhances to a lethal level under stress conditions referred to as oxidative stress. While, under normal conditions, cells are capable of dealing with ROS using non-enzymatic and enzymatic defense system, it can lead to a critical damage to cell system via the oxidation of cellular components under stress condition. Lipid peroxidation is a well-established mechanism of cellular injury in all kinds of organisms and it is often used as an indicator of oxidative stress in cells and tissues. In the presence of metal ions, ROS such as hydrogen peroxide (H2O2) produces highly reactive hydroxyl radical (HO•) via Fenton reaction. In the current study, we have used the porcine skin (intact pig ear/skin biopsies) as an ex vivo/in vitro model system to represent human skin. Experimental results have been presented on the participation of HO• in the initiation of lipid peroxidation and thereby leading to the formation of reactive intermediates and the formation of electronically excited species eventually leading to ultra-weak photon emission (UPE). To understand the participation of different electronically excited species in the overall UPE, the effect of a scavenger of singlet oxygen (1O2) on photon emission in the visible and near-infrared region of the spectrum was measured which showed its contribution. In addition, measurement with interference filter with a transmission in the range of 340–540 nm reflected a substantial contribution of triplet carbonyls (3L=O∗) in the photon emission. Thus, it is concluded that during the oxidative radical reactions, the UPE is contributed by the formation of both 3L=O∗ and 1O2. The method used in the current study is claimed to be a potential tool for non-invasive determination of the physiological and pathological state of human skin in dermatological research.
Highlights
The skin plays diverse essential functions such as protection against environment, metabolism, thermoregulation, sensation, and excretion (Zouboulis, 2009; Morrow and Lechler, 2015)
The skin consists of the epidermis, which forms the outermost layer followed by dermis and subcutis/hypodermis which is the deepest layer
The kinetics of ultra-weak photon emission (UPE) was measured from the porcine skin biopsies after the topical application of Fenton’s reagent using visible photomultiplier tube (PMT) (Figures 4A,B)
Summary
The skin plays diverse essential functions such as protection against environment, metabolism, thermoregulation, sensation, and excretion (Zouboulis, 2009; Morrow and Lechler, 2015). The dermis contains extracellular molecules secreted by support cells that provide structural and biochemical support to the adjacent/surrounding cells and consists of a dense network of tough elastic collagen fibres and bundles of proteins (elastin) found in the extracellular matrix. These make the skin strong and robust while at the same time elastic (Tepole et al, 2012). During the oxidative stress generated by abiotic stresses (toxic chemicals, exposure to ultraviolet irradiations, etc.), the epidermal and dermal cells are known to be most affected (Rinnerthaler et al, 2015; Ji and Li, 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
