00:00Photobiomodulation, or red light therapy, is a process by which light is used to activate the cells in our body.
00:10This is a phenomenon that was first discovered by a Hungarian scientist in 1967 by the name of Andrzej Meshte.
00:20This he discovered while working with lasers as a side effect of the laser therapy.
00:30As a result, red light therapy was originally called LLLT, or low-level laser therapy.
00:41Scientists soon realized that LEDs, or light-emitting diodes, can also produce the same effect.
00:51Red light, having the longest wavelength of the visible spectrum, penetrates skin more deeply than the other colors in the visible spectrum.
01:03Since then, red light and near-infrared light have become popular modalities for the treatment of a number of medical conditions.
01:17Red light and near-infrared light can repair and rejuvenate tissues, having a variety of beneficial effects.
01:28The packets of light, called photons that are absorbed, are absorbed by molecules in the tissues, known as chromophores.
01:37The process is similar to the way our eyes sense light rays, but form the images that we see.
01:46In red light therapy, light is absorbed by three main chromophores as it crosses the skin.
01:52In the outer layer of the skin, or the epidermis, light is absorbed by melanin across a broad range of wavelengths,
02:04from 400 to 700, which constitutes the visible spectrum and beyond.
02:10In the deeper portion of the skin, or the dermis, hemoglobin is the main chromophore,
02:18and this absorbs light in a broad spectrum with two distinct peaks at around 420 nanometers and 580 nanometers.
02:32Throughout the layers of the skin, water molecules are scattered,
02:36and these to absorb light across a broad range of wavelengths.
02:43The biological effects of light therapy come from the photomodulation of specific structures in the cell.
02:52One of the most important structures is the mitochondrion.
02:57The mitochondrion acts as the powerhouse of the cell.
03:01It is here that all the energy of the cell is produced for it to perform its functions.
03:08When the mitochondrion is stimulated, the cell wakes up.
03:14Its activity increases, and it produces new hormones and proteins and important molecules called cytokines.
03:26Cytokines can increase or decrease inflammation.
03:30They can also help with the maturation of stem cells,
03:36or they can attract other cells to the site of phototherapy.
03:41The mitochondrion absorbs light mainly through a molecule that is found in its membrane.
03:49This molecule is called the cytokine C oxidase,
03:53which absorbs light in a range from 670 to 950 nanometers,
04:02with the maximum absorption taking place at 810 nanometers wavelength light.
04:11These wavelengths extend into the infrared range of electromagnetic radiation.
04:19The absorption of light by the cytokine C oxidase releases nitric oxide from inside the molecule.
04:30This unleashes a flood of secondary messengers into the cell,
04:35such as calcium ions and reactive oxygen species and CAMP and ATP and transcription factors.
04:46These increase the activity of the cell and lead to a production of proteins and hormones and cytokines like we mentioned before.
04:59Because the mitochondria act as the major chromophores in the cell,
05:07tissues that are rich in mitochondria are more sensitive to red light therapy.
05:14Tissues such as brain and muscle and nerve that are rich in mitochondria are more sensitive
05:23and therefore require a lower dose of red light therapy to produce a given effect.
05:32In red light therapy, myrrh is not always better.
05:36The response of tissue to light therapy is consistent with the phenomenon of hormesis,
05:46which states that a substance in a low dose may be helpful,
05:53but in higher doses, it can be harmful.
05:57This means that there is an optimal red light dose for best results.
06:03Surpassing this dose may not only impede the process,
06:10but may actually cause harm.
06:13In the skin, one notable characteristic of red light therapy is the activation of fibroblasts.
06:23Fibroblasts are the cells that produce collagen in the skin.
06:27Collagen is the protein that provides the structure in the skin that gives it its texture.
06:37In humans, aging skin is characterized by a loss in collagen fibers.
06:46This causes the skin to sag and produce wrinkles.
06:51The stimulation of fibroblasts can reverse this process
06:58by increasing the amount of collagen in the skin.
07:03This can rejuvenate the skin and eliminate wrinkles.
07:08I hope you found this video informative.
07:10If you did, like and share the video with your friends and family.
07:16Until the next video, stay healthy and stay safe.
Comments