Photobiomodulation increases cell viability via AKT activation in an in vitro model of diabetes induced by glucose neurotoxicity

Photobiomodulation for diabetes and its complications: a review of general presentation, mechanisms and efficacy

Diabetes mellitus is a metabolic disease that is marked by persistent hyperglycemia due to inadequate insulin secretion or insulin resistance. Its prevalence is increasing yearly. Diabetes mellitus can lead to serious health complications that are the primary cause of mortality and disability among diabetic patients, including diabetic retinopathy, diabetic foot ulcers, diabetic peripheral neuropathy, and diabetic periodontitis, and so on. Traditional treatments for diabetes and its complications still suffer from limited clinical efficacy and high therapeutic side effects. Photobiomodulation (PBM), which utilizes low levels of red or near-infrared laser to irradiate cells and tissues, has been shown to be efficacious for a wide range of organ damage. In this study, we focus on the application of PBM in diabetes and its complications and mechanisms, as well as the advantages, disadvantages with the aim of developing new ideas for the application of PBM.

Effectiveness of Photobiomodulation Therapy on Neuropathic Pain, Nerve Conduction and Plantar Pressure Distribution in Diabetic Peripheral Neuropathy - A Systematic Review

BACKGROUND

Diabetic peripheral neuropathy is a severe complication of type 2 diabetes mellitus. The most common symptoms are neuropathic pain and altered sensorium due to damage to small nerve fibers. Altered plantar pressure distribution is also a major risk factor in diabetic peripheral neuropathy, leading to diabetic foot ulcers.

OBJECTIVE

The objective of this systematic review was to analyze the various studies involving photobiomodulation therapy on neuropathic pain and plantar pressure distribution in diabetic peripheral neuropathy.

METHODS

We conducted a systematic review (PubMed, Web of Science, CINAHL, and Cochrane) to summarise the evidence on photobiomodulation therapy for Diabetic Peripheral Neuropathy with type 2 diabetes mellitus. Randomized and non-randomized studies were included in the review.

RESULTS

This systematic review included eight studies in which photobiomodulation therapy showed improvement in neuropathic pain and nerve conduction velocity. It also reduces plantar pressure distribution, which is a high risk for developing foot ulcers.

CONCLUSION

We conclude that photobiomodulation therapy is an effective, non-invasive, and costefficient means to improve neuropathic pain and altered plantar pressure distribution in diabetic peripheral neuropathy.

Long-term exposure to high glucose induces changes in the expression of AMPA receptor subunits and glutamate transmission in primary cultured cortical neurons

Hyperglycemia, which occurs under the diabetic conditions, induces serious diabetic complications. Diabetic encephalopathy has been defined as one of the major complications of diabetes, and is characterized by neurochemical and neurodegenerative changes. However, little is known about the effect of long-term exposure to high glucose on neuronal cells. In the present study, we showed that exposure to glutamate (100 mM) for 7 days induced toxicity in primary cortical neurons using the MTT assay. Additionally, high glucose increased the sensitivity of AMPA- or NMDA-induced neurotoxicity, and decreased extracellular glutamate levels in primary cortical neurons. In Western blot analyses, the protein levels of the GluA1 and GluA2 subunits of the AMPA receptor as well as synaptophysin in neurons treated with high glucose were significantly increased compared with the control (25 mM glucose). Therefore, long-term exposure to high glucose induced neuronal death through the disruption of glutamate homeostasis.

Photobiomodulation in diabetic wound healing: A review of red and near-infrared wavelength applications

The development of a painless, non-invasive, and faster way to diabetic wound healing is at the forefront of research. The complexity associated with diabetic wounds makes it a cause for concern amongst diabetic patients and the world at large. Irradiation of cells generates a photobiomodulatory response on cells and tissues, directly causing alteration of cellular processes and inducing diabetic wound repair. Photobiomodulation therapy (PBMT) using red and near-infrared (NIR) wavelengths is being considered as a promising technique for speeding up the rate of diabetic wound healing, eradication of pain and reduction of inflammation through the alteration of diverse cellular and molecular processes. This review presents the extent to which the potential of red and NIR wavelengths have been harnessed in PBMT for diabetic wound healing. Important research challenges and gaps are identified and discussed, and future directions mapped out. This review thus provides useful insights and strategies into improvement of PBMT, including its acceptance within the global medical research community.

Effect of low power lasers on prokaryotic and eukaryotic cells under different stress condition: a review of the literature

Radiations emitted by low power radiation sources have been applied for therapeutic proposals due to their capacity of inactivating bacteria and cancer cells in photodynamic therapy and stimulating tissue cells in photobiomodulation. Exposure to these radiations could increase cell proliferation in bacterial cultures under stressful conditions. Cells in infected or not infected tissue injuries are also under stressful conditions and photobiomodulation-induced regenerative effect on tissue injuries could be related to effects on stressed cells. The understanding of the effects on cells under stressful conditions could render therapies based on photobiomodulation more efficient as well as expand them. Thus, the objective of this review was to update the studies reporting photobiomodulation on prokaryotic and eukaryotic cells under stress conditions. Exposure to radiations emitted by low power radiation sources could induce adaptive responses enabling cells to survive in stressful conditions, such as those experienced by bacteria in their host and by eukaryotic cells in injured tissues. Adaptive responses could be the basis for clinical photobiomodulation applications, either considering their contraindication for treatment of infected injuries or indication for treatment of injuries, inflammatory process resolution, or tissue regeneration.

Photobiomodulation Therapy for the Management of Chemotherapy-Induced Peripheral Neuropathy: An Overview

Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of chemotherapy (CT), affecting 68% of patients. Current treatment strategies are based on pharmacological symptom management, but have limited results. Photobiomodulation therapy (PBMT) is a new and emerging therapeutic tool in the supportive care of cancer patients. In this overview, we explore the usability of PBMT for management of CIPN. Objective: To provide a comprehensive overview of management of CIPN with PBMT. Methods: Specific terms, including "Photobiomodulation Therapy," "Drug Therapy," and "Peripheral Nervous System Diseases," were identified for the literature research in PubMed. Results: Three articles were considered eligible for this review. Primary outcome measures were highly variable across the included studies. Conclusions: PBMT might be an effective treatment strategy to manage CIPN, with very encouraging reports from renowned teams, but evidence is limited. More methodologically uniform research (mainly regarding the parameters of PBMT) is needed to support the use of PBMT for this indication.

Can photobiomodulation therapy (PBMT) control blood glucose levels and alter muscle glycogen synthesis?

Photobiomodulation therapy (PBMT) has many effects on the energy metabolism of musculoskeletal tissue, such as increased glycogen and adenosine triphosphate synthesis. In addition, these effects may be due to a systemic blood glucose control. Twenty-four Wistar rats were randomly and equally allocated into four groups: sham, PBMT 10 J/cm², PBMT 30 J/cm² and PBMT 60 J/cm². The animals were fasting for 6 h for blood glucose evaluations during pre-irradiation period, 1 h, 3 h and 6 h after PBMT. Muscle glycogen synthesis was measured 24 h after PBMT. This PBMT used a cluster of 69 LEDs (light-emitting diodes) with 35 red (630 ± 10 nm) and 34 infrared (850 ± 20 nm); 114 mW/cm² for 90s (10 J/cm²), 270 s (30 J/cm²), 540 s (60 J/cm²) applied on large muscle areas (back and hind legs) of the animals. The 10 J/cm² group showed lower blood glucose levels and glucose variability over 6 h (5.92 mg/dL) compared to the sham (13.03 mg/dL), 30 J/cm² (7.77 mg/dL) and 60 J/cm² (9.07 mg/dL) groups. The PBMT groups had the greatest increase in muscle glycogen (10 J/cm² > 60 J/cm² > 30 J/cm² > sham), characterizing a triphasic dose-response of PBMT. There was a strong negative correlation between blood glucose variability over 6 h and muscle glycogen concentration for 10 J/cm² group (r = -0.94; p < .001) followed by 30 J/cm² group (r = -0.84; p < .001) and 60 J/cm² group(r = -0.73; p < .006). These results suggest that PBMT can play a very important role in the control of blood glucose levels, and its possible mechanism of action is the induction of greater muscle glycogen synthesis independently of physical exercise.