Visible lights effect on oxidative stress.
Research type
Research Study
Full title
An investigation into the effect of different wavelengths of light, when administered n conjunction with oral nitrate, on concentrations of oxidative stress markers, before and after a CPET, in healthy, active individuals.
IRAS ID
168811
Contact name
Martin Feelisch
Contact email
Duration of Study in the UK
0 years, 4 months, 16 days
Research summary
Nitric oxide (NO) is integral to the human physiological response to hypoxia (lack of oxygen). Levett D et al (2011). In a critical care setting, hypoxia may arise as a result of multiple organ malfunctions and ultimately contributes to patient mortality (death), so any measures that can be taken to decrease a patient’s need for oxygen to fulfil normal bodily functions will have an impact on survival.
In healthy individuals, nitrate (the major end product of NO breakdown and also a ubiquitous constituent of our diet) has been shown to reduce the oxygen cost of exercise. Larsen F et al (2010). Thus, nitrate administration may also lower the need for oxygen in critically ill patients.
UVA light has been shown to increase concentrations of NO independently of NO synthase activity. It has been investigated in relation to blood pressure and blood flow regulation, but the mechanisms underpinning this are unknown. Liu D et al (2014). Literature suggests that effects of UVA light are mainly derived from vitamin D. Research showed improved exercise performance when exposed to UVA light during the summer months. Cannell JJ. Et al (2009). The mechanism related to increased performance was ascribed to vitamin D, however, its effects are rather slow (within 24 h) and cannot account for many of immediate effects of UVA light. With vitamin D an unlikely candidate for short or transient changes, the role of NO will be investigated.
It has been hypothesised that the release of NO is via preformed stores in the skin as a result of UVA irradiation. This release was shown to have a measureable reduction on blood pressure demonstrating a systemic effect of the NO on the cardiovascular system. Liu D et al (2014).
Dietary nitrate has been demonstrated to lower upon blood pressure and have a favourable effect on other cardiometabolic risk factors. Kapil V et al. (2010). The hypothesis that NO stored in and released from skin exists in large enough quantities to exert a measureable effect is based upon the observations made by Liu et al (2014) who identified a measureable reduction in blood pressure as a result of NO released from skin.
Following on from this, a research project is currently underway at the university of Southampton, investigating whether UVA light does indeed mediate the release of NO and therefore increase the bodies ability to use oxygen, and decrease the oxidative stress in relation to an insult, in this case, exercising on a bike.
This research will expand upon this current work, by using both a group that has been administered antibacterial mouthwash, hence preventing any oral nitrate being converted to nitrite, which is then converted to NO in the body, as well as using different wavelengths of light within the visible spectrum. The adverse effects of UVA light are commonly known, and include medical conditions such as skin cancer if a person is exposed for too long without protection. However, if it were found that a wavelength in the relatively safe visible spectrum mediated the same effect with regards to oxygen consumption, there is a real possibility that this could be used in future interventions to enable patients to be in a better physical condition before undergoing treatments that exert a great insult upon bodily systems, such as surgery and chemotherapy, and therefore decrease the rates of complications and deaths.
REC name
West of Scotland REC 5
REC reference
15/WS/0017
Date of REC Opinion
3 Feb 2015
REC opinion
Further Information Favourable Opinion