Effect of Calendula officinalis cream on achilles tendon healing.

In recent years, the scientific community has undertaken research on plant extracts, searching for compounds with pharmacological activities that can be used in diverse fields of medicine. Calendula officinalis L. is known to have antioxidant, anti-inflammatory, antibacterial, and wound healing properties when used to treat skin burns. Therefore, the purpose of this study was to analyze the effects of C. officinalis on the initial phase of Achilles tendon healing. Wistar rats were separated in three groups: Calendula (Cal)-rats with a transected tendon were treated with topical applications of C. officinalis cream and then euthanized 7 days after injury; Control (C)-rats were treated with only vehicle after transection; and Normal (N)-rats without tenotomy. Higher concentrations of hydroxyproline (an indicator of total collagen) and non-collagenous proteins were observed in the Cal group in relation to the C group. Zymography showed no difference in the amount of the isoforms of metalloproteinase-2 and of metalloproteinase-9, between C and Cal groups. Polarization microscopy images analysis showed that the Cal group presented a slightly higher birefringence compared with the C group. In sections of tendons stained with toluidine blue, the transected groups presented higher metachromasy as compared with the N group. Immunocytochemistry analysis for chondroitin-6-sulfate showed no difference between the C and Cal groups. In conclusion, the topical application of C. officinalis after tendon transection increases the concentrations of collagen and non-collagenous proteins, as well as the collagen organization in the initial phase of healing.

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.

Arrabidaea chica extract improves gait recovery and changes collagen content during healing of the Achilles tendon.

INTRODUCTION: Tendon lesions are still a serious clinical problem. The leaves of the Bignoniaceae Arrabidaea chica (Humb. & Bonpl.) B. Verlot. (syn. Bignonia chica (Bonpl.)) have been used in traditional medicine and described in the literature for its healing properties. However, no study has shown the effects of A. chica during tendon healing. The aim of this study was to investigate the healing properties of the A. chica leaves extract on tendons after partial transection. METHODS: A partial transection in the tension region of the Achilles tendon of rats was performed with subsequent posterior topical application of A. chica extract (2.13g/mL in 0.85% saline solution) at the site of the injury. The animals (n=154) were separated into 7 groups: N - rats with tendons without transection; S7, S14 and S21 - rats with tendons treated with topical applications of saline for 7 days and sacrificed on the 7th, 14th and 21st days after surgery, respectively; A7, A14 and A21 - rats with tendons treated with topical applications of the plant extract. The transected regions of the tendons were analyzed through biochemical, morphological and functional analyses. To evaluate the type and concentration of collagen, Western blotting for collagen types I and III was performed, and the hydroxyproline concentration was determined. The participation of metalloproteinases (MMP)-2 and -9 during tendon remodelling was investigated through zymography. Gait recovery was analyzed using the catwalk system. The organization of the extracellular matrix and morphometry were detected in sections stained with haematoxylin-eosin. RESULTS: The application of A. chica extract in the region of tendon injury led to an increase in the amount of hydroxyproline (mg/g tissue) on the 7th (91.5±18.9) and 21st (95.8±11.9) days after the tendon lesion relative to the control groups treated with saline (S7: 75.2±7.2; and S21: 71.9±7.9). There were decreases in collagen types I and III (as determined by densitometry) in the groups treated with the plant extract 7 days after injury (type I: 103.9±15.9; type III: 206.3±8.1) compared to the saline-treated groups (type I: 165.2±31.1; type III: 338.6±48.8). The plant extract stimulated the synthesis of MMP-2 on the 21st day after the lesion and decreased the amount of latent and active isoforms of MMP-9 on the 14th day. Analysis by the catwalk system (max contact intensity) showed that the A. chica extract improved the gait of rats on the 7th day of the healing process when compared to the saline group. CONCLUSIONS: The use of A. chica extract during the healing process of the tendon leads to an increase in collagen content and improved gait recovery. Further studies will be performed to analyze the effect of this plant extract on the organization of the collagen bundles of tendons after lesions and to study its probable anti-inflammatory effect.

Structural and biochemical alterations during the healing process of tendons treated with Aloe vera.

AIMS: The tendon is composed of highly organized collagen fibers that form a complex supramolecular structure. After lesions, the organization and composition of the tendon are not completely restored. Our purpose was to evaluate if the application of Aloe vera improves tendon healing, considering the effectiveness in the stimulus of collagen synthesis. MAIN METHODS: The calcaneal tendon of male Wistar rats was partially transected with subsequent topical application of A. vera ointment at the injury. The animals were separated into groups with tendons treated with the A. vera extract for 7days and excised on the 7th, 14th and 21st days after surgery; control rats received only ointment base without plant extract. KEY FINDINGS: Morphological analysis using polarization microscopy showed that the entire tendon undergoes a remodeling process, with disorganized collagen fibers by days 7 and 14 in plant-treated and non-treated groups and with a higher birefringence in tendons of the plant-treated group on the 21st day. A higher concentration of hydroxyproline was found in plant-treated tendons on days 7 and 14 compared with their controls. Western blots showed lower amounts of type I collagen in the plant-treated group on day 14 compared with the control. MMP-9 diminished 14days after lesion and the active isoform of MMP-2 increased on day 21 in plant-treated groups. SIGNIFICANCE: The present study indicates a beneficial effect of A. vera in the tissue reorganization in the transected region of the tendon 21days after injury and is supported by an increase of active MMP-2.