Mitochondrial Rejuvenation and NIR

Rejuvenation of Mitochondria using Near Infra Red Light

Maybe I am just behind the times, but when my optician mails me with red-light treatment for my aging eyes (which will ‘stimulate and rejuvenate my mitochondria ) and in the same week a friend is having some one shining a red torch onto the backside of her horse, it is obviously time to do some internet searching.

What I found pretty quickly is that:

a) photobiomodulation therapy (PBM)  is everywhere and

b)  640nm LEDs are the cheap and easy reason for the ‘torches’ and variants on that theme

However, as my optician is no charlatan,  a bit more research was demanded which, after a long story, has resulted in me purchasing a 810nm high-powered LED complete with heat sink. Experiments will follow.

Below is ‘the story’ behind PBM and it’s very interesting.

Background:

1. Electrochemistry in mitochondria

The generation of chemical free energy by mitochondria is, broadly, in the form of the molecule ATP. ATP production depends on generating an electrochemical potential across a membrane and is mediated within that membrane by  a series of connected electron transporting proteins known as cytochromes.  The process is ultimately oxidative (hydrogen and oxygen combine to form water) and the cytochrome flash between oxidised and reduced forms as they play pass the parcel with an endless supply of electrons obtained from hydrogen.

2. Photochemistry of cytochromes

The clue as to their photo-sensitivity is in the ‘chrome’ part of their name. Light absorption is inevitable, as at their heart is the molecular ‘cage’ of a porphyrin ring which  embraces  a metal ion. This ion’s (usually copper) day job is to accept and release electrons thus becoming ‘reduced’ and ‘oxidised’ in turn. The ring’s structure though, being analogous to those molecules in plants which trap light for a living as part of the photosynthetic process means that light trapping is always ‘on the cards’/

It’s reasonable to assume then, that mitochondria’s photosensitivity is an atavistic legacy from a distant photosynthetic past inherited by their cytochrome structures. Even so, biology never lets an opportunity pass it by if it can be leveraged and scientists never let an opportunity pass that can be exploited!

Humans like most non-photosynthetic organisms are impermeable to light, but not all light.

The near infra-red penetrates skin well, it feels warm on the skin and carries on deeper into the tissues. This light can be seen as visible red light at the 600-700nm range becoming ‘dark’ by 800nm.

‘Bottom Line’

It has been long known and shown over and over, that mitochondria can and do absorb NIR light and that NIR can affect their activity either stimulating or inhibiting ATP production. And so onto its application and significance.

Red Light Therapy

‘Torches’ that emit red light at safe low levels at around 640nm ( the peak from standard IR LEDs) are routinely used as therapy to treat skin ailments and eyes. The theory goes that the mitochondria are stimulated, producing more ATP which promotes healing and performance ( rejuvenation). 

Naturally enough given their bogey-man status, the concomitant  increase in free radical production (ROS) is not mentioned, nor awkwardly, is the fact that some NIR wavelengths stimulate and other inhibit. 

Harder Science for practical application of NIR

NIR enhances mitochondrial activity by stimulating cytochrome c oxidase (COX) at 810nm. BUT it inhibits COX at 750nm and 950nm. 

I can find no such detailed data at red led’s 640nm. The absorption spectrum of COX shows that the stimulated oxidised form of its copper ion is at 670nm and 810nm. As a result I suspect  visible red light treatments may be less effective than ideal at when the main light source is at 640nm.

In any case, the conclusion is that the wavelength of NIR matters and that broad spectrum of wavelengths may cause inhibition as well as stimulation of mitochondria.

My interest rests at the 810nm absorbtion for which fortunately there is a powerful LED readily available. I have not carried out any experiments yet but the diode has arrived and works. 

What is the point of stimulating the mitochondria within say skin or eye tissue?

Retrograde signalling? 

In a previous blog I went into detail about mitochondrial control of ‘nuclear’ genes relevant to its own integrity. The mitochondrial response to NIR is another potential mechanism for signalling to the transcription factors in the nucleus. Firstly there are noted variations in the inner membrane’s electrical potential, secondly there is an associated production of nitric oxide and thirdly increased ROS production gas, all three are capable of communication with the nucleus. But what? if anything, they are talking about is a mystery.

Various theories exist as to environmental, natural responses to red light. Sunrise and sunset being cited as red-light rich cues. Dawn is proposed as a signal that a high UV session is coming. This seems fanciful and not persuasive. Another is that NIR stimulates  repair mechanisms. This is not so fanciful. The increased ROS production will cause mild inflammation signalling repair processes to increase. In this case ‘deep heat’ would be well served by sitting close to an open fire!.

The whole area of red-light therapy is fascinating and I am looking forward to trying it out. I am pretty sure that NIR at 810nm will stimulate mitochondria but what effect it will have and how deep is a question. Luckily I have my own sore muscles, joints and even an old horse to work on.