Clin Should Elbow.  2019 Jun;22(2):79-86. 10.5397/cise.2019.22.2.79.

The Evaluation of Exogenous Melatonin Administration in Supraspinatus Overuse Tendinopathy in an Experimental Rat Model

• Kocadal O
• Pepe M
• Akyurek N
• Gunes Z
• Surer H
• Aksahin E
• Ogut B
• Aktekin CN

• KMID: 2449434
• DOI: http://doi.org/10.5397/cise.2019.22.2.79

Abstract

BACKGROUND
Increased oxidative stress and inflammation play a critical role in the etiopathogenesis of chronic tendinopathy. Melatonin is an endogenous molecule that exhibits antioxidant and anti-inflammatory activity. The aim of this study was to evaluate the biochemical and histopathological effects of exogenous melatonin administrations in supraspinatus overuse tendinopathy.
METHODS
Fifty rats were divided into the following four groups: cage activity, melatonin treatment, corticosteriod therapy, and control. Melatonin (10 mg/kg, intraperitoneal; twice a day) and triamcinolone (0.3 mg/kg, subacromial; weekly) were administered to the treatment groups after the overuse period. Biochemical and histopathological evaluations were performed on serum samples and biopsies obtained from rats. Plasma inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF), total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) levels were evaluated biochemically.
RESULTS
The TAS, TOS, OSI, iNOS, and VEGF values were significantly lower than the pre-treatment levels in rats receiving exogenous melatonin treatment (3 or 6 weeks) (p<0.05). TOS, iNOS, VEGF, and OSI values after 3 weeks of triamcinolone administration, and TOS, VEGF, and OSI levels after 6 weeks of triamcinolone application, were significantly lower than the pre-treatment levels (p<0.05).
CONCLUSIONS
Exogenous melatonin application in overuse tendinopathy reduces oxidative stress and inflammation. Melatonin might be an alternative potential molecule to corticosteroids in the treatment of chronic tendinopathy.

Keyword

Shoulder; Rotator cuff; Tendinopathy; Oxidative stress; Melatonin

MeSH Terms

Adrenal Cortex Hormones
Animals
Biopsy
Inflammation
Melatonin*
Models, Animal*
Nitric Oxide Synthase Type II
Oxidative Stress
Plasma
Rats*
Rotator Cuff
Shoulder
Tendinopathy*
Triamcinolone
Vascular Endothelial Growth Factor A
Adrenal Cortex Hormones
Melatonin
Nitric Oxide Synthase Type II
Triamcinolone
Vascular Endothelial Growth Factor A