Influence of leukotriene inhibitor montelukast on wound contraction and cutaneous healing process in rats

Montelukast, an Antagonist of Cysteinyl Leukotriene Signaling, Impairs Burn Wound Healing

BACKGROUND

Burns are severe injuries often associated with impaired wound healing. Impaired healing is caused by multiple factors, including dysregulated inflammatory responses at the wound site. Interestingly, montelukast, an antagonist for cysteinyl leukotrienes and U.S. Food and Drug Administration approved for treatment of asthma and allergy, was previously shown to enhance healing in excision wounds and to modulate local inflammation.

METHODS

In this study, the authors examined the effect of montelukast on wound healing in a mouse model of scald burn injury. Burn wound tissues isolated from montelukast- and vehicle-treated mice at various times after burn injury were analyzed for wound areas ( n = 34 to 36), reepithelialization ( n = 14), inflammation ( n = 8 to 9), and immune cell infiltration ( n = 3 to 6) and proliferation ( n = 7 to 8).

RESULTS

In contrast to previously described beneficial effects in excision wounds, this study shows that montelukast delays burn wound healing by impairing the proliferation of keratinocytes and endothelial cells. This occurs largely independently of inflammatory responses at the wound site, suggesting that montelukast impairs specifically the proliferative phase of wound healing in burns. Wound healing rates in mice in which leukotrienes are not produced were not affected by montelukast.

CONCLUSION

Montelukast delays wound healing mainly by reducing the proliferation of local cells after burn injury.

CLINICAL RELEVANCE STATEMENT

Although additional and clinical studies are necessary, our study suggests that burn patients who are on montelukast may exhibit delayed healing, necessitating extra observation.

MOntelukast as a potential CHondroprotective treatment following Anterior cruciate ligament reconstruction (MOCHA Trial): study protocol for a double-blind, randomized, placebo-controlled clinical trial

BACKGROUND

After anterior cruciate ligament (ACL) reconstruction, patient-reported outcomes are improved 10 years post-surgery; however, cytokine concentrations remain elevated years after surgery with over 80% of those with combined ACL and meniscus injuries having posttraumatic osteoarthritis (PTOA) within 10-15 years. The purpose of this multicenter, randomized, placebo-controlled trial is to assess whether a 6-month course of oral montelukast after ACL reconstruction reduces systemic markers of inflammation and biochemical and imaging biomarkers of cartilage degradation.

METHODS

We will enroll 30 individuals undergoing primary ACL reconstruction to participate in this IRB-approved multicenter clinical trial. This trial will target those at greatest risk of a more rapid PTOA onset (age range 25-50 with concomitant meniscus injury). Patients will be randomly assigned to a group instructed to take 10 mg of montelukast daily for 6 months following ACL reconstruction or placebo. Patients will be assessed prior to surgery and 1, 6, and 12 months following surgery. To determine if montelukast alters systemic inflammation following surgery, we will compare systemic concentrations of prostaglandin E2, monocyte chemoattractant protein-1, and pro-inflammatory cytokines between groups. We will also compare degradative changes on magnetic resonance imaging (MRI) collected 1 and 12 months following surgery between groups with reductions in early biomarkers of cartilage degradation assessed with urinary biomarkers of type II collagen breakdown and bony remodeling.

DISCUSSION

There is a complex interplay between the pro-inflammatory intra-articular environment, underlying bone remodeling, and progressive cartilage degradation. PTOA affects multiple tissues and appears to be more similar to rheumatoid arthritis than osteoarthritis with respect to inflammation. There is currently no treatment to delay or prevent PTOA after ACL injury. Since there is a larger and more persistent inflammatory response after ACL reconstruction than the initial insult of injury, treatment may need to be initiated after surgery, sustained over a period of time, and target multiple mechanisms in order to successfully alter the disease process. This study will assess whether a 6-month postoperative course of oral montelukast affects multiple PTOA mechanisms. Because montelukast administration can be safely sustained for long durations and offers a low-cost treatment option, should it be proven effective in the current trial, these results can be immediately incorporated into clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04572256 . Registered on October 1, 2020.

Leukotriene receptor antagonist reduces inflammation and alveolar bone loss in a rat model of experimental periodontitis

BACKGROUND

Leukotrienes (LTs) participate in the process of tissue damage in periodontal disease by leukocyte chemotaxis and osteoclastic activation. The activation of Cysteinyl-LT receptor is associated with increased expression of proinflammatory molecules and osteoclastogenesis. However, its implications on periodontal disease progression have not been studied. The present study evaluated the effect of the cysteinyl-LT receptor antagonist (montelukast [MT]) on ligature-induced experimental periodontitis (EP) in rats.

METHODS

Adult male Wistar rats were subjected to bilateral ligature-induced periodontitis and orally treated with MT (at doses of 10 or 30 mg/kg/d, MT10, and MT30, respectively). Sham animals had the ligatures immediately removed and received placebo treatment. Sets of animals were euthanized 7, 14, or 21 days after ligature placement and the mandibles were removed for macroscopic evaluation of alveolar bone loss (ABL). In addition, histological analysis of periodontal tissues, myeloperoxidase (MPO) activity of gingival tissues, and periodontal tissue expression of collagen type I, RUNX2, RANK, RANKL, OPG, BLT1, Cys-LTR1, LTA4H, and LTC4S were also analyzed.

RESULTS

MT significantly reduced ABL at 14 (MT10 and MT30) and 21 days (MT10) (P < 0.05), gingival MPO at 7 (MT10) and 14 days (MT30) (P < 0.05), LTA4H, BLT1 and LTC4S gene expression on day 14 day (MT30, P < 0.05) and increased RUNX2 expression on day 14 (MT30, P < 0.05).

CONCLUSION

Systemic therapy with MT decreases periodontal inflammation and ABL in ligature-induced periodontitis in rats.

Effects of montelukast sodium on tendon healing: An experimental study

INTRODUCTION

Montelukast sodium (MS) a selective leukotriene antagonist of the cysteinyl leukotriene receptor, has been used in the treatment of asthma and allergic rhinitis. In this study, we evaluated the effect of MS on the early inflammatory phase (histological) of nonsynovial tendon healing.

MATERIALS AND METHODS

Rats were divided randomly into two groups (n = 6 each). MS (Singulair) was administered to one group at 10 mg/kg/day [250 g/day intraperitoneally (i.p.)]. The control group was administered 250 g/day of 0.9% saline i.p. This nonsynovial tendon was longitudinally divided at the midportion, cut transversely and then sutured. In both groups, the rats were sacrificed by decapitation 10 days later.

RESULTS

Decreased inflammatory cell infiltration and more properly oriented collagen fibres were observed in the MS group's histopathological specimens as compared to the control group's (P < 0.05). Additionally, vascularity was decreased in the MS group.

CONCLUSION

MS decreased tendon healing, apparently by inhibiting the early inflammatory phase of nonsynovial tendon healing.

Wound contraction is attenuated by fasudil inhibition of Rho-associated kinase

BACKGROUND

Dermal scarring and scar contracture result in restriction of movement. There are no effective drugs to prevent scarring. RhoA and Rho-associated kinase have emerged as regulators of fibrosis and contracture. Fasudil, a Rho-associated kinase inhibitor, has been demonstrated to have antifibrotic effects in models of liver, renal, and cardiac fibrosis. The role of fasudil in preventing dermal scarring and contractures has not been studied. The authors used a rat model of dermal wound healing to assess the effects of fasudil with regard to the prevention of scarring.

METHODS

Human scar tissue and surrounding normal skin were immunostained for RhoA and Rho-associated kinase. Full-thickness wounds were created on Wistar-Han rats, and fasudil (30 mg/kg/day) or saline was continuously delivered subcutaneously. Wound contraction was measured by gravitational planimetry. After 21 days, tissue was harvested for Masson's trichrome, hematoxylin and eosin, Ki-67, and CD31 staining. Fibroblast-populated collagen lattices were used to assess the mechanistic effects of fasudil on contractility. Myofibroblast formation was assessed in the presence of fasudil.

RESULTS

Human scar tissue in the remodeling phase of repair showed increased expression of RhoA and Rho-associated kinase in scar tissue compared with surrounding normal tissue. Fasudil inhibited wound contraction as compared with controls. Hematoxylin and eosin and Masson's trichrome were similar between groups. Fasudil did not alter angiogenesis or proliferation. Fasudil inhibited fibroblast contractility and myofibroblast formation in vitro.

CONCLUSIONS

There is growing evidence that the RhoA/Rho-associated kinase pathway plays an important role in wound healing and scar contracture. The authors present data showing that inhibition of Rho-associated kinase hinders fibroblast contractility and may be beneficial in preventing scar contracture.

Dual Inhibition of Wound Healing and Oxidative Process by Montelukast in Experimental Colon Anastomoses

Background. The authors aimed to investigate the effects of montelukast (ML) on the experimental rat colon anastomosis. Methods. A total of 80 Wistar albino rats were divided into 4 groups: sham-operated, colon anastomosis, and colon anastomosis with oral administration (OAML) and rectal administration of 10 mg/kg/d ML (RAML). Anastomotic bursting pressure, anastomotic hydroxyproline contents, malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPX), and superoxide dismutase (SOD) levels, and the expressions of Ki-67, vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (bFGF) with immunohistochemistry were assessed on postoperative day 5. Results . Anastomotic bursting pressures and bFGF expressions were not changed, whereas tissue hydroxyproline concentrations and MDA levels and the expressions of Ki-67 and VEGF were significantly decreased, and GSH, GPX, and SOD levels were significantly increased in the OAML and RAML groups. Conclusion. ML causes impairment of wound healing without altering the anastomosis bursting pressure and reverses the oxidative damage of the colon anastomoses in rats.