Condition Focus: Acute Gouty Arthritis — Neuromodulatory Approach

Most photobiomodulation research in joint disease applies light directly to the inflamed joint. This 2023 study from Pinto and colleagues took a different approach — targeting the dorsal root ganglion (DRG), the cluster of sensory nerve cell bodies in the spinal column that relays pain and inflammatory signals from the joint to the central nervous system.

Using a well-established rat gout model (monosodium urate crystal injection into the ankle joint), the researchers applied a combined LASER (808 nm, 100 mW) and LED (850 nm, 80 mW) cluster to the DRG region at a dose of 4 J/cm² per diode, seven hours after gout induction. This is notable for two reasons: the combined LASER + LED delivery method, and the neuromodulatory rather than local anti-inflammatory strategy.

The results showed that a single PBM session on the DRG reduced both edema and pain behaviours in the gout model animals. Interestingly, the study also observed increased IL-1β levels and leukocyte recruitment in the treated group — suggesting that PBM may support the immune system’s resolution phase rather than simply suppressing all inflammatory activity. The antioxidant system was also activated, indicating a dual mechanism of neuromodulation and oxidative stress management.

This study is significant because it demonstrates that PBM can address gout pain through neural pathways, not just through local tissue effects at the joint surface. It also confirms that combined LASER + LED delivery — similar in concept to the G.O.A.T.’s dual-wavelength design — is effective in a gout-specific model.

G.O.A.T. for Gout Alignment:
The G.O.A.T. delivers 660 nm + 850 nm wavelengths in a combined LED configuration, closely paralleling the 808 nm LASER + 850 nm LED cluster used in this study. While the G.O.A.T. targets the joint directly rather than the DRG, the dual-wavelength approach and the 4 J/cm² fluence used here align with the G.O.A.T.’s dosimetry. The finding that 850 nm NIR penetrates to deeper structures supports the G.O.A.T.’s use of this wavelength for the MTP joint.

Link to original research here

Editor’s note: This is one of only three studies in our library using a gout-specific disease model. For the landmark human RCT comparing PBM to diclofenac in acute gout, see Soriano et al 2006. The edema reduction observed here through neural pathways complements the direct anti-edema effects shown via cannabinoid receptor activation in Neves et al 2018. For PBM’s effects on synovial tissue inflammation — the tissue layer where urate crystals deposit — see Ryu et al 2023.

Related Articles

• PBM of Pain and Inflammation in Microcrystalline Arthropathies – Soriano et al 2006
• Acupuncture Combined with Infrared Irradiation for Acute Gouty Arthritis – Zhu et al 2011
• PBM Improves Acute Inflammation via Cannabinoid Receptor Activation – Neves et al 2018
• PBM Ameliorates Inflammatory Parameters in Fibroblast-Like Synoviocytes – Ryu et al 2023
• Effect of PBM on Inflammatory Mediators and Neutrophils in Joint Inflammation – Alves et al 2014

Key Takeaways

• Single PBM session on the dorsal root ganglion reduced both edema and pain in a gout model
• Combined LASER (808 nm) + LED (850 nm) cluster delivery used at 4 J/cm² per diode
• Neuromodulatory approach — targeting the pain signal pathway rather than just the inflamed joint
• Antioxidant system activation observed alongside immune priming, suggesting resolution-phase support
• First study to use combined LASER + LED in a gouty arthritis model

Study Overview

Full Citation

Pinto HD, Vanin AA, Miranda EF, Tomazoni SS, Johnson DS, Albuquerque-Pontes GM, Antonialli FC, Grandinetti VS, Parizotto NA, de Carvalho PT, Leal-Junior ECP. (2023). Acute effects of photobiomodulation applied on the dorsal root ganglion in gout model-induced rats. Journal of Photochemistry and Photobiology B: Biology, 239, 112644. View Publication