Green tea and glycine aid in the recovery of tendinitis of the Achilles tendon of rats

Abstract

Purpose: Green tea (GT) is widely used due to its anti-inflammatory properties. Previous studies have shown beneficial effects of a glycine diet on the remodeling process in inflamed tendons. Tendinitis is commonly observed in athletes and is of concern to surgeons due to the slowness of the recovery process. Our hypothesis is that GT?+?a glycine diet may improve tendinitis. Aim of the study: To analyze the effect of GT and/or glycine in the diet on tendinitis. Materials and methods: Wistar rats were divided into seven groups (G): control group (C); G1 and G4, tendinitis; G2 and G5, tendinitis supplied with GT; and G3 and G6, tendinitis supplied with GT and a glycine diet for 7 or 21 days, respectively. We performed zymography for metalloproteinase, biochemical, morphological and biomechanics tests. Results: G2, G3 and G5 showed high levels of hydroxyproline in relation to G1, while G4 showed high levels of glycosaminoglycans. High activity of metalloproteinase-2 was detected in G3. The organization of collagen bundles was better in G2 and G3. G5 showed similar birefringence measurements compared with C. G5 withstood a larger load compared with G4. Conclusions: The presence of metalloproteinase-2 indicates that a tissue is undergoing a remodeling process. High birefringence suggests a better organization of collagen bundles. After 21 days, G5 sustained a high load before rupture, unlike G4. The results suggest that GT?+?a glycine diet has beneficial effects that aid in the recovery process of the tendon after tendinitis.