Combined extract (Curcuma longa-Glycyrrhiza glabra) alleviates the inflammations of Achilles tendinopathy in Wistar rats.

Abstract

Achilles tendinopathy is a frequent pathological condition in adults with overused ankles, causing microtrauma, inducing tenocyte apoptosis and inflammatory response. Common treatment involves oral prescription or injection of anti-inflammatory agents, surgery, or shock-wave therapy. However, prolonged administration is not advisable due to adverse effects. Therefore, a novel and safe regimen is needed. Curcuma longa and Glycyrrhiza glabra extracts are known for their anti-inflammatory effects owing to their active compounds (curcumin and glycyrrhizin, respectively). This study aimed to determine the effect of combined extracts of Curcuma longa and Glycyrrhiza glabra on tendon healing in an animal model of Achilles tendinopathy (Wistar rats). This study took place from February to May 2022 and compared the regimens administered to 32 animal models of Wistar rats with 4 healthy rats as a control group to determine the most effective therapeutic regimen: immobilization, immobilization with ibuprofen, or immobilization with the combined extract. The outcomes were measured to find which intervention provided the lowest inflammatory markers [High Mobility Group Box-1 (HMGB-1), Tumor Necrosis Factor-α (TNF-α), Chemokin motif ligand 12 (CXCL-12)], and improved tissue morphology represented by the BONAR score, decreased cross-sectional area (CSA), and increased Macrophage 2 (M2) differentiation. After Achilles tendinopathy was induced, total immobilization (I1) was proven to be the most effective with the lowest CSA, whereas immobilization+175 mg/kg Curcuma longa+110 mg/kg Glycyrrhiza glabra extract (I5) was the most effective with the lowest HMGB-1 levels and the lowest CXCL-12 levels. Immobilization+131 mg/kg Curcuma longa+82.5 mg/kg Glycyrrhiza glabra extract (I6) was the most effective with the lowest Bonar score, while immobilization+87.5 mg/kg Curcuma longa+55 mg/kg Glycyrrhiza glabra extract (I7) was proven to be the most effective with the highest M2 coverage area and the lowest TNF-α levels. We found that combined extract therapy was the most effective intervention for treating Achilles tendinopathy due to its ability to provide the lowest inflammatory markers.