Biological and biochemical effects of light therapy in horses

This clinical study investigates the biological and biochemical effects of solarium light therapy in horses, focusing on its therapeutic potential through the combination of infrared and visible red light. Light therapy in horses provides photobiomodulation, which improves cellular functions, reduces inflammation, and enhances circulation. Red light therapy stimulates mitochondrial activity, aiding tissue repair and antioxidant production, which is crucial for sport and aging horses. The study analyzes hematological parameters, oxidative stress markers, and biochemical reactions to determine age-related therapeutic efficacy. As natural light decreases in winter, artificial light therapy can provide significant physiological support, making this research valuable for optimizing equine health management strategies.

This study investigated the effects of light therapy on blood parameters and antioxidant potential in ten geldings from the University of Warmia and Mazury, divided into young (5–7 years old) and older (14–19 years old) groups. The study was conducted from late November to December 2021 at the Equestrian Center, where horses underwent ten light therapy sessions using infrared and UV lamps. Blood samples were collected before therapy, after five sessions, and after ten sessions to assess various hematological indicators and antioxidant enzyme activities. The results indicated age-related changes in blood parameters and a varied response to light therapy, particularly in antioxidant levels and enzyme activities, with younger horses showing increased resistance compared to older ones.

Orzołek A, Rafalska KT, Domosławska-Wyderska A, Rafalska AM, Dziekońska A, Jastrzębska E, Dobbek D. Effect of Solarium Light Therapy on Selected Biological and Biochemical Parameters of Peripheral Blood in Young and Old Horses. PLoS One. 2024 May 24;19(5):e0304290. doi: 10.1371/journal.pone.0304290. PMID: 38787841; PMCID: PMC11125486.

https://doi.org/10.1371/journal.pone.0304290

The study evaluated the impact of phototherapy on blood parameters and antioxidant capacity in ten geldings divided into two age groups: young (5–7 years) and older (14–19 years). The research was conducted in winter at the Equestrian Center of the University of Warmia and Mazury. Horses underwent ten 15-minute phototherapy sessions every other day. Blood samples were collected at three time points: before therapy, after five sessions, and after ten sessions. Various hematological tests were performed, including white and red blood cell analysis, as well as assessment of antioxidant enzyme activities such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR).

The results indicate a significant decrease in red blood cell (RBC) count, white blood cell (WBC) count, and platelet (PLT) count with increasing age in horses, suggesting a reduced bone marrow response. The study found a notable decrease in lymphocyte count and an increase in neutrophil count in older horses, confirming established observations. Analysis of antioxidant activity showed that while SOD activity did not correlate with age, GPx activity was distinctly higher in older horses. Conversely, younger horses exhibited elevated GR activity.

Light therapy in horses improved erythrocyte membrane fluidity, leading to stable red blood cell (RBC) counts and hemoglobin levels. The therapy also altered other parameters, such as increasing mean corpuscular volume (MCV) and red blood cell distribution width (RDW). Light therapy showed potential for improving blood indicators and antioxidant enzyme activities in horses, with increased effectiveness observed in the younger group.

The results of the variance analysis confirmed a significant effect of age on various blood parameters:

• Lymphocyte count (LYMPH): significantly higher in younger horses.
• Neutrophil count (NEUT): higher in older horses.
• Hemoglobin content: higher in older horses.
• Mean corpuscular volume (MCV): higher in older horses (p ≤ 0.05).
• Mean corpuscular hemoglobin (MCH): higher in older horses (p ≤ 0.05).
• Mean reticulocyte hemoglobin content (CHr): higher in older horses (p ≤ 0.05).
• Mean platelet volume (MPV): higher in older horses (p ≤ 0.05).

• Glutathione peroxidase (GPx) activity: significantly higher in older horses.
• Glutathione reductase (GR) activity: similar in both groups, but over twice as high in erythrocytes of younger horses (p ≤ 0.05).
• Plasma glutathione (GSH) content: significantly higher in younger horses.
• Erythrocyte GSH levels: comparable between groups.
• Plasma vitamin C content: higher in younger horses (p ≤ 0.05).
• Malondialdehyde (MDA) levels: lower in older animals (p ≤ 0.05).

• Morphological indices — therapy affects: MCV, MCHC, RDW, HDW, MCVr, CHr, MPV.

• Catalase (CAT) activity: decreased in the plasma of younger animals after therapy.
• Glutathione peroxidase (GPx): increased in the plasma of younger animals.
• Glutathione reductase (GR): increased in younger animals.
• Total antioxidant status (TAS): gradually increased during therapy (p ≤ 0.05).
• Reticulocyte count: in older horses, a significant decrease occurred after 5 sessions.
• Erythrocyte parameters: positive effects—increased MCV, HDW, MCVr, CHr, and MPV.

• Plasma vitamin C levels: therapy-dependent, significant differences between age groups.
• D3 levels: no statistically significant differences between age groups.

• Glutathione reductase (GR) activity: varied effects depending on age.
• Total antioxidant status (TAS): largely dependent on both factors.
• Antioxidant enzymes: GPx and GR activity in erythrocytes showed variability—younger horses respond more favorably.

Overall, the combination of age and light therapy provided insights into optimizing health and antioxidant support in horse care.

The study found that the use of light therapy with a solarium positively influences both blood parameters and antioxidant capacity in recreational horses during the winter period. Key findings indicate an increase in hematological indicators such as MCV, HDW, reticulocyte indices, and MPV. In young horses, a significant increase in white blood cells and monocytes was observed, in contrast to the older group, which showed a decrease in reticulocyte count.

Vitamin C and glutathione (GSH) were identified as key antioxidants, while GPx and GR activity varied according to GSH demand. Phototherapy proved more beneficial for younger horses. These findings highlight the potential of phototherapy as a method to support equine health and performance, especially in managing oxidative stress during winter months.

The information contained in this article is for educational and informational purposes only. It does not constitute medical advice, diagnosis, or treatment recommendations. Before starting any therapy, consult a qualified physician or specialist. Lumaflex is not responsible for the consequences of using the information contained in this article without appropriate medical consultation.

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