Catching Up With Dr. Praveen Arany on Red Light Therapy
We recently caught up with Dr. Praveen Arany, Assistant Professor at the Department of Oral Biology, School of Dental Medicine at the University of Buffalo School of Dental Medicine. Dr. Arany participated in enabling the MASCC/ISOO guidelines that recommend using photobiomodulation (PBM), otherwise known as light therapy, in the prevention and treatment of oral mucositis, a debilitating side effect of cancer treatment.
In this conversation, Dr. Arany tells us about his background, how he became interested in photobiomodulation, what excites him about its clinical future, and more.
Joovv: What piqued your interest in researching wound healing & tissue regeneration with photobiomodulation?
Dr. Praveen Arany: As a pathology resident in 1999, I came across two incredible papers. The first suggested that ‘tumors are non-healing wounds’. This began my scientific interest in exploring possible avenues to modulate wound healing, with the naïve hope that someday we could use this approach to control tumor outcomes.
I came across the original work by Mester on the fascinating ability of low dose laser treatments (who termed it photostimulation) to promote wound healing. The non-invasive nature and precision seemed very attractive. Most medical professionals are not exposed to any formal aspect of light and human health, so the improbability of using ‘light’ for medical treatments raised significant skepticism in my mind. Thus, I resolved to pursue this field and have been singularly focused on this question most of my professional career.
Joovv: Light is somewhat abstract, and light therapy can be a difficult treatment to understand for the general population. In layman’s terms, how do you describe PBM to your colleagues and/or patients that are less familiar with it?
Dr. Praveen Arany: In most of my talks, I usually begin by highlighting the current use of light in various biological processes such as vision, sunlight and vitamin D, and our daily circadian rhythm. These are concepts most folks are familiar with and tends to emphasize the fact that our human body uses light for its normal physiological functions. Hence, the use of low dose light treatments, such as for photobiomodulation treatment, appears to be a logical extension of these routine processes.
Joovv: Can you tell us what the mechanism of action is for PBM, and where more research needs to be done in this area?
Dr. Praveen Arany: This is a key question. As with any treatment modality, it’s not possible for PBM to be used for such a broad spectrum of myriad of medical applications with any one single mechanism. We need to explore individual mechanisms of action for each clinical scenario so we are able to optimize treatment protocols.
There has been recent description of several molecular mechanisms for PBM therapy. As the field is still evolving (the name PBM was only formalized in 2015 after much angst and debate!), three discrete PBM mechanisms have been described – one within the mitochondria involving the much described cytochrome C oxidase (improves performance); the second involving cell membrane, light-responsive receptors and ion channels (targets pain and inflammation). Finally, a third mechanism described by our lab involves activation of a growth factor that is capable of directing stem cell differentiation (promote healing and tissue regeneration).
There is likely much crosstalk between these three mechanisms where each one is useful to various degrees. I would like to emphasize that recent evidence in the past few years is moving us away from the much touted cytochrome C oxidase mitochondrial PBM mechanism.
Joovv: You mentioned there are 9 areas you’d like to focus on for PBM. Could you elaborate?
Dr. Praveen Arany: At a recent meeting of the World Association of Photobiomodulation Therapy (WALT) in Nice, France, we outlined evidence for nine areas where there appears to be credible clinical and research evidence. These include musculoskeletal and sports medicine, neurorehabilitative, supportive care in cancer, dentistry, veterinary, wound healing, acupuncture and regenerative medicine. We are in the final phases of completing four of these key WALT position papers and expect they will be published by summer 2020. This should not only promote better clinical care and research studies but also, very importantly, enable regulatory policies and educational initiatives.
Joovv: Are you studying PBM in any other therapeutic areas? Where do you see other potential areas that it can treat?
Dr. Praveen Arany: We are actively exploring many of these nine areas but our approach has been to primarily focus on the fundamental underlying pathophysiology such as pain, inflammation, immune responses and wound healing. Our lab utilizes a broad spectrum of model systems from cell cultures, biomaterial scaffolds, animal models and human clinical studies. Of these several areas, we have made most progress in regenerative dentistry, wound healing and neurorehabilitation (concussion). We have several collaborations with industry partners - key stakeholders – who are enabling this therapy to forge into mainstream medicine.
Joovv: Your research helped change MASCC/ISOO guidelines to use PBM therapy in the prevention and treatment of oral mucositis. Can you give us an overview of the study, and why this is so significant?
Dr. Praveen Arany: Cancer treatments have improved over the past few decades with significant improvements in mortality rates. However, an unfortunate side-effect of cancer treatments such as chemotherapy, radiation or bone marrow transplants for various types of cancers is the incidence of ulcers and pain in the mouth, termed oral mucositis.
To address these oral ulcers, PBM was initially attempted based on the rationale from Mester’s original work on promoting healing. Several studies noted striking efficacy in both treatment as well as prevention of oral mucositis. Subsequent controlled clinical studies generated clear evidence that led to a systematic review and meta-analyses in 2014 that noted this efficacy and set the stage for improved clinical study design and further attention to treatment parameters. In a recent 2019 analyses of this literature, 35 well done clinical studies noted the striking benefits of using PBM treatment that has led to the upgrade of the MASCC recommendations to mainstream care (clinical practice guidelines).
Several groups, including ours, have outlined specific therapeutic PBM mechanisms involving TRPV1, NFκB and TGF-β that contribute to the observed clinical benefits with PBM treatments in oral mucositis. The improved understanding of these pathways has enabled careful monitoring of PBM responses and optimizing their treatment regimens for more rigorous, reproducible clinical outcomes.
Joovv: Are there any patient stories that really stick out in your mind about the difference PBM has made in his or her life?
Dr. Praveen Arany: A recent case with an elderly gentleman who received PBM treatments with a specific laser unit for musculoskeletal (neck and upper back) pain showed significant relief. In follow up visits, we used a similar wavelength LED unit and observed comparable efficacy. Most interestingly, another discrete wavelength at the same treatment dose was less effective and the dose had to be suitably adjusted to elicit a therapeutic response.
This reinforces the concept of using light as a drug, a Photoceutical - utilizing the right wavelength and dose! We should be paying attention to both the device parameters (photodynamics) as well as the biological responses (photokinetics).
Joovv: Have you come across any adverse events using PBM?
Dr. Praveen Arany: We have noted excessive dosing results in delays in healing and negates any therapeutic benefits.
There is another critical issue for our field. It seems to largely focus on the type of device being used to perform PBM. Several laser PBM devices are now available. While they appear to be more efficient with specific biological responses but appear to have a narrow therapeutic window. On the other hand, LED PBM devices are much more ‘forgiving’ (larger therapeutic window) and are capable of being formatted into large arrays (reducing treatment time) and are more affordable. We did, however, note they were somewhat less efficient in evoking a robust PBM response in our studies.
My personal opinion is that given the potential for inadvertent damage, the laser PBM devices could be restricted to clinical delivery systems while the LED-based devices can be utilized in a broader clinical (wellness) and non-clinical (home-use) format.
Joovv: Outside of research, what's your personal experience with red and near infrared light therapy?
Dr. Praveen Arany: Various forms of light therapy are quite popular and readily available such as heating (NIR) lamps or ‘mood’ environmental lighting systems. Light-based devices are also popular in surgery (high power lasers) for their precision (eg; LASIK) and concurrent coagulation (blood-less fields) as well as photodynamic therapy. The latter technique utilizes an exogenous photosensitizer (eg; dye or nanoparticle) with a low dose light source to destroy tumor cells or microbes. In biology, especially neurosciences, there is tremendous excitement with optical imaging and optogenetics. All these techniques use light devices in varying wavelengths.
In contrast to all of these, PBM represents a unique niche for application of a therapeutic low dose light whose benefits are only now being fully appreciated. It is also worth pointing out that light is one of the few physical attributes that spans the tiniest subatomic particles to the most used cosmological constant - light years!
Joovv: What other health-related topics are you really curious about right now?
Dr. Praveen Arany: Nutrition, meditation and exercise. The more we pursue precision medicine, we can consider light as an ‘external’ signal to our body and we need to account for other ‘inputs’ for health. The ultimate goal of medicine must be to treat the entire patient and not their disease alone.
Joovv: Any other thoughts you’d like to leave people with?
Dr. Praveen Arany: Besides its use as a treatment tool, PBM is poised to revolutionize our fundamental concepts of human health by providing insights into various pathophysiological processes (eg; TBI).
Light hygiene, light as a health supplement and general ‘health’ lighting are all areas that are potentially poised to benefit from the therapeutic concepts of PBM, and I’m very excited about all of the potential opportunities in this field.