Photobiomodulation therapy mitigates cardiovascular aging and improves survival

Abstract

Background: Photobiomodulation (PBM) therapy, a form of low-dose light therapy, has been noted to be effective in several age-associated chronic diseases such as hypertension and atherosclerosis. Here, we examined the effects of PBM therapy on age-associated cardiovascular changes in a mouse model of accelerated cardiac aging. Methods: Fourteen months old Adenylyl cyclase type VIII (AC8) overexpressing transgenic mice (n = 8) and their wild-type (WT) littermates (n = 8) were treated with daily exposure to Near-Infrared Light (850 nm) at 25 mW/cm 2 for 2 min each weekday for a total dose of 1 Einstein (4.5 p.J/cm 2 or fluence 3 J/cm 2 ) and compared to untreated controls over an 8-month period. PBM therapy was administered for 3.5 months (Early Treatment period), paused, due to Covid-19 restrictions for the following 3 months, and restarted again for 1.5 months. Serial echocardiography and gait analyses were performed at monthly intervals, and serum TGF-β1 levels were assessed following sacrifice. Results: During the Early Treatment period PBM treatments: reduced the ageassociated increases in left ventricular (LV) mass in both genotypes (p = 0.0003), reduced the LV end-diastolic volume (EDV) in AC8 (p = 0.04); and reduced the left atrial dimension in both genotypes (p = 0.02). PBM treatments substantially increased the LV ejection fraction (p = 0.03), reduced the aortic wall stiffness (p = 0.001), and improved gait symmetry, an index of neuro-muscular coordination (p = 0.005). The effects of PBM treatments, measured following the pause, persisted. Total TGF-β1 levels were significantly increased in circulation (serum) in AC8 following PBM treatments (p = 0.01). We observed a striking increase in cumulative survival in PBM-treated AC8 mice (100%; p = 0.01) compared to untreated AC8 mice (43%). Conclusion: PBM treatment mitigated age-associated cardiovascular remodeling and reduced cardiac function, improved neuromuscular coordination, and increased longevity in an experimental animal model. These responses correlate with increased TGF-β1 in circulation. Future mechanistic and dose optimization studies are necessary to assess these anti-aging effects of PBM, and validation in future controlled human studies is required for effective clinical translation.

Exploring the Potential of Energy-Based Therapeutics (Photobiomodulation/Low-Level Laser Light Therapy) in Cardiovascular Disorders: A Review and Perspective

“…These effects persisted after the pause, and cumulative survival increased in PBM-treated AC8 mice. PBM treatment was found to mitigate age-associated cardiovascular remodeling, reduce cardiac function, enhance neuromuscular coordination, and increase longevity in an experimental animal model, with responses correlating with elevated TGF-β1 in circulation [28].…”

“…Low-level laser therapy (LLLT) can alter the expression of cardiac cytokines and assists in the reversal of ventricular remodeling following myocardial injury [26]. Moreover, photobiomodulation (PBM) therapy has been shown to be effective in several age-associated chronic cardiovascular conditions, such as hypertension and atherosclerosis [28]. In this review, the focus is on examining the evidence-based investigations concerning the application of photobiomodulation therapy in cardiovascular diseases and to analyze their major propositions and recommendations.…”

“…Syed et al [28] discovered that early PBM treatments reduced age-associated increases in left ventricular (LV) mass, decreased LV end-diastolic volume (EDV) in AC8, lowered left atrial dimension, enhanced LV ejection fraction, alleviated aortic wall stiffness, and improved gait symmetry. These effects persisted after the pause, and cumulative survival increased in PBM-treated AC8 mice.…”

“…Furthermore, PBM has been used to delay the presentation of age-related cardiac disorders. A recent study by Syed et al [28] suggests that PBM therapy could mitigate age-associated cardiovascular remodeling and improve cardiac function, neuromuscular coordination, and longevity in an experimental animal model. Additionally, the observed responses correlated with increased TGF-β1 levels in circulation [28].…”

“…A recent study by Syed et al [28] suggests that PBM therapy could mitigate age-associated cardiovascular remodeling and improve cardiac function, neuromuscular coordination, and longevity in an experimental animal model. Additionally, the observed responses correlated with increased TGF-β1 levels in circulation [28]. These findings indicate that PBM therapy may have promising benefits in preventing or slowing cardiovascular aging and may serve as a potential therapeutic strategy for age-related cardiovascular diseases in the future.…”