Repurposing of Angiotensin-converting-enzyme Inhibitor on Prevention of Post-surgical Tendon Adhesion.

BACKGROUND: Formation of adhesion bands is a frequent clinical complication after tendon injury or surgery with limited treatment options. This study investigates the repurposing of Angiotensin-Converting-Enzyme Inhibitor (ACEI) in attenuating post-operative tendon-sheath adhesion bands in an Achilles tendon rat model. METHODS: Structural, mechanical, histological, and biochemical characteristics of the Achilles tendons were compared in the presence and absence of oral ACEI (enalapril) using the Achilles tendon adhesion (TA) model in rats. Inflammation and total fibrosis of tendon tissues were compared between groups using molecular investigations along with macroscopic and histological scoring methods. RESULTS: ACEI significantly alleviated the severity, length, and density of Achilles TAs. Moreover, histopathological changes, recruitment of inflammatory cells, and inflammation were significantly decreased in post-operative tissue samples as quantified with the Moran scoring model. We showed that ACEI treatment elicits a potent anti-fibrotic effect on tendon tissue samples, as illustrated by decreasing the severity and extent of the formed fibrotic tissue and collagen accumulation at the site of surgery when scored either by Tang or Ishiyama grading systems. The H&E staining showed no histopathological changes or damage to the principal organs. CONCLUSION: Our results showed that ACEI is a safe and effective therapeutic candidate with potent immunomodulatory and anti-fibrotic features to alleviate surgery-induced development of fibrotic adhesive tissue. However, its efficacy needs to be further validated in clinical studies.

Exploring new therapeutic potentials of curcumin against post-surgical adhesion bands.

BACKGROUND: Adhesion band formation is a common cause of morbidity for patients undergoing surgeries. Anti-inflammatory and anti-fibrotic properties of curcumin, a pharmacologically active component of Curcuma longa, have been investigated in several studies. The aim of this study is to explore the therapeutic potential of curcumin in attenuating post-operative adhesion band (PSAB) formation in both peritoneal and peritendinous surgeries in animal models. METHODS: Bio-mechanical, histological and quantitative evaluation of inflammation, and total fibrosis scores were graded and measured in the presence and absence of phytosomal curcumin. RESULTS: Results showed that phytosomal curcumin significantly decreased severity, length, density and tolerance of mobility of peritendinous adhesions as well as incidence and severity of abdominal fibrotic bands post-surgery. Curcumin may decrease inflammation by attenuating recruitment of inflammatory cells and regulating oxidant/anti-oxidant balance in post-operative tissue samples. Moreover, markedly lower fibrosis scores were obtained in the adhesive tissues of phytosomal curcumin-treated groups which correlated with a significant decrease in quantity, quality and grading of fibers, and collagen deposition in animal models. CONCLUSION: These results suggest that protective effects of phytosomal curcumin against PSAB formation is partially mediated by decreasing inflammation and fibrosis at site of surgery. Further studies are needed to investigate the therapeutic potential of this molecule in preventing PSAB.

Effect of angiotensin II pathway inhibitors on post-surgical adhesion band formation: a potential repurposing of old drugs.

BACKGROUND: In this study we investigated the therapeutic potential of angiotensin II pathway inhibitors in attenuating post-surgical adhesion band formation in tendon injury. METHOD: We assigned 30 Wistar albino rats to 5 groups, including negative control, positive control, sham, Telmisartan- and Enalapril-treated groups (n=6). Telmisartan and Enalapril at a dose of 10 mg/kg were administered intraperitoneally for 21 days. Hematoxylin-Eosin, and Masson's trichrome staining were used to measure the inflammatory cell accumulation and collagen deposition in the Achilles tendon tissue sections. Oxidative stress markers were analyzed in tissue samples by spectrophotometric methods. Properties of Achilles tendon adhesions were compared based on Tang and Ishiyama scoring systems in the presence and absence of angiotensin II pathway inhibitors. RESULTS: Telmisartan and Enalapril reduced severity, length, and density of surgical-induced tendon adhesion at site of injury (***p < 0.001). Our results showed that administration of angiotensin II pathway inhibitors decreased infiltration of inflammatory cells to the injured area (*p < 0.05) and suppressed inflammation by regulating oxidative stress markers including MDA (***p < 0.001), total thiol (***p < 0.001), CAT (***p < 0.001), and SOD (***p < 0.001), in post-operative Achilles tendon tissues. Significant lower collagen deposition and formation of fibrotic tissues was seen in Telmisartan- and Enalapril-treated groups as detected by Masson's trichrome staining which correlated with a decrease in quantity (**p < 0.01) and grading of fibrosis score (***p < 0.001), in adhesive tissues. Moreover, inhibition of angiotensin II pathway could also ameliorate mechanical properties including ultimate load (***p < 0.001), and ultimate stress (*p < 0.05) in injured Tendons. CONCLUSION: Our results showed that ssuppression of inflammation and fibrosis are two mechanisms by which Telmisartan and Enalapril elicit potent protective responses post Achilles tendon injuries.

Mebendazole, an anti-helminth drug, suppresses inflammation, oxidative stress and injury in a mouse model of ulcerative colitis.

Mebendazole (MBZ) is an efficacious anthelmintic with known anti-inflammatory and fibrinolytic properties. In this study, we aimed to explore the protective effects of this FDA-approved drug against DSS-induced colitis in a murine model either alone or in combination with Sulfasalazine (SSZ), a standard therapy for ulcerative colitis. We found that MBZ significantly improved colitis disease activity index as assessed by changes in body weight, degree of stool consistency, rectal bleeding, and prolapse. We also found that MBZ ameliorated the colon histopathological score by attenuating crypt loss, mucosal damage, and inflammation score in colitis tissues. Similarly, DSS-induced colon shortening, colon weight loss, and increase in spleen weight were all abrogated in the presence of MBZ. Moreover, MBZ decreased inflammation, possibly by reducing oxidative stress markers, suppressing inflammatory cell infiltration, and down-regulation of inflammatory genes in colon tissues. Furthermore, MBZ potently reduced fibrosis by decreasing collagen deposition and down-regulating pro-fibrotic genes including Col 1a1 and Col 1a2 in colitis tissue homogenates. In conclusion, our study showed that this broad-spectrum anthelminthic could be repurposed as a novel therapy for ulcerative colitis without any observed side effects, however, regarding the concerns about the potential toxicity of MBZ in UC patients, future experiments on MBZ therapy in other models of UC is needed to completely address the toxicity concerns.