The fluence effects of low-level laser therapy on inflammation, fibroblast-like synoviocytes, and synovial apoptosis in rats with adjuvant-induced arthritis.

Abstract

OBJECTIVE:

The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) operating at low and high fluences on joint inflammation, fibroblast-like synoviocytes (FLS), and synovial apoptosis in rats with adjuvant-induced arthritis.

BACKGROUND DATA:

Rheumatoid arthritis (RA) is characterized by pronounced inflammation and FLS proliferation within affected joints. Certain data indicate that LLLT is effective in patients with inflammation caused by RA; however, the fluence effects of LLLT on synovium are unclear.

METHODS:

Monoarthritis was induced in adult male Sprague-Dawley rats (250-300 g) via intraarticular injection of complete Freund's adjuvant (CFA) into the tibiotarsal joint. Animals were irradiated 72 h after CFA administration with a 780 nm GaAlAs laser at 4.5 J/cm2 (30 mW, 30 sec/spot) and 72 J/cm2 (80 mW, 180 sec/spot) daily for 10 days. After LLLT, the animals were euthanized and their arthritic ankles were collected for histopathological analysis, immunoassays of tumor necrosis factor (TNF)-α, matrix metallopeptidase (MMP)3 and 5B5, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays.

RESULTS:

LLLT at a fluence of 4.5 J/cm2 significantly reduced infiltration of inflammatory cells and expressions of TNF-α-, MMP3- and 5B5-like immunoreactivities, as well as resulting in more TUNEL-positive apoptotic cells in the synovium. No significant changes were observed in these biochemicals and inflammation in arthritic animals treated with 72 J/cm2.

CONCLUSIONS:

LLLT with low fluence is highly effective in reducing inflammation to sites of injury by decreasing the numbers of FLS, inflammatory cells, and mediators in the CFA-induced arthritic model. These data will be of value in designing clinical trials of LLLT for RA.

• Authors: Yueh-Ling Hsieh, Yu-Jung Cheng, Fang-Chuen Huang, Chen-Chia Yang
• Journal: Photomedicine and laser surgery (Photomed Laser Surg) Vol. 32 Issue 12 Pg. 669-77 (Dec 2014) ISSN: 1557-8550 [Electronic] United States
• PMID: 25394331 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Animals
• Apoptosis (radiation effects)
• Arthritis, Experimental (radiotherapy)
• Fibroblasts (radiation effects)
• Immunohistochemistry
• In Situ Nick-End Labeling
• Inflammation (radiotherapy)
• Lasers, Semiconductor (therapeutic use)
• Low-Level Light Therapy (methods)
• Male
• Rats
• Rats, Sprague-Dawley
• Synovial Membrane (cytology, radiation effects)