Effect of the Arrabidaea chica extract on collagen fiber organization during healing of partially transected tendon

Aims: After undergoing lesions, tendons have disorganized collagen fibers compared to undamaged tendons. Arrabidaea chica leaves have the aglycones carajurin and carajurone, components of the antocyanins, with a strong pharmacological potential due to their healing properties. Thus, the aim of this study was to investigate the effect of topical application of A. chica extract during tendon healing. Main methods: The calcaneal tendon of Wistar rats was partially transected with subsequent treatment with A. chica extract (2.13 g/mL) followed by excision on the 7th, 14th and 21st days. Control rats received only saline treatment. Key findings: Transmission electron microscopy analysis showed the presence of a large amount of small segments of collagen fibrils in the transected region of the tendons on the 7th day in both the control and plant-treated groups. Considering the organization of the collagen fibers, higher values of birefringence were observed under polarization microscopy in the tendons of the plant-treated group on the 14th day compared to the control group. A larger quantity of dermatan sulfate was also detected after plant treatment in the same period. However, lesser dermatan and chondroitin sulfate were detected in the plant-treated group than in the control group on the 21st day. No differences were found in the values of birefringence between these groups. Intense metachromasy was observed in both transected groups on the 21st day. Significance: In conclusion, the use of A. chica extract improves collagen organization and increases the quantity of dermatan sulfate on the 14th day of the tendon healing. (C) 2013 Elsevier Inc. All rights reserved.