Antiadhesive and anti-inflammatory effects of pirfenidone in postoperative intra-abdominal adhesion in an experimental rat model

Effects of linalool on postoperative peritoneal adhesions in rats

The current study examines the effects of linalool in preventing postoperative abdominal adhesions. Twenty male Wistar rats were randomly divided into four groups. (1) Sham: in this group, the abdomen was approached, and without any manipulations, it was sutured. (2) Control: rats in this group underwent a surgical procedure to induce adhesions. This involved making three incisions on the right abdominal side and removing a 1×1-cm piece of the peritoneum on the left abdominal side. (3) Treatment groups: these groups underwent the same surgical procedure as the control group to induce adhesions. Animals in these groups received linalool orally with doses of 50 and 100 mg/kg, respectively, for a period of 14 days. Moreover, rats in the sham and control groups received normal saline via gavage for 14 days. The evaluation of TNF-α, TGF-β, VEGF, and caspase 3 was performed using western blot and IHC methods. Furthermore, oxidative stress biomarkers such as MDA, TAC, GSH, and NO were assessed in the peritoneal adhesion tissue. The findings revealed that linalool significantly reduced peritoneal adhesions by reducing TNF-α, TGF-β, VEGF, and caspase 3 levels. Moreover, MDA concentration was significantly decreased, while NO, TAC, and GSH levels were notably increased. Overall, linalool was effective in preventing adhesion formation and reduced inflammation, angiogenesis, apoptosis, and oxidative stress. Therefore, linalool as a potent antioxidant is suggested for reducing postoperative adhesions in rats.

Pirfenidone improves voiding function by suppressing bladder fibrosis in underactive bladder rats

Underactive bladder (UAB), characterized by a complex set of symptoms with few treatment options, can significantly reduce the quality of life of affected people. UAB is characterized by hyperplasia and fibrosis of the bladder wall as well as decreased bladder compliance. Pirfenidone is a powerful anti-fibrotic agent that inhibits the progression of fibrosis in people with idiopathic pulmonary fibrosis. In the current study, we evaluated the efficacy of pirfenidone in the treatment of bladder fibrosis in a UAB rat model. UAB was induced by crushing damage to nerve bundles in the major pelvic ganglion. Forty-two days after surgery, 1 mL distilled water containing pirfenidone (100, 300, or 500 mg/kg) was orally administered once every 2 days for a total of 10 times for 20 days to the rats in the pirfenidone-treated groups. Crushing damage to the nerve bundles caused voiding dysfunction, resulting in increased bladder weight and the level of fibrous related factors in the bladder, leading to UAB symptoms. Pirfenidone treatment improved urinary function, increased bladder weight and suppressed the expression of fibrosis factors. The results of this experiment suggest that pirfenidone can be used to ameliorate difficult-to-treat urological conditions such as bladder fibrosis. Therefore, pirfenidone treatment can be considered an option to improve voiding function in patient with incurable UAB.

Combination of losartan with pirfenidone: a protective anti-fibrotic against pulmonary fibrosis induced by bleomycin in rats

Pirfenidone (PFD), one acceptable medication for treating idiopathic pulmonary fibrosis (IPF), is not well tolerated by patients at full doses. Hence, employing of some approaches such as combination therapy may be applicable for increasing therapeutic efficacy of PFD. Losartan (LOS), an angiotensin II receptor antagonist, could be a suitable candidate for combination therapy because of its stabilizing effect on the pulmonary function of IPF patients. Therefore, this study aimed to investigate the effects of LOS in combination with PFD on bleomycin (BLM)-induced lung fibrosis in rats. BLM-exposed rats were treated with LOS alone or in combination with PFD. The edema, pathological changes, level of transforming growth factor-β (TGF-β1), collagen content, and oxidative stress parameters were assessed in the lung tissues. Following BLM exposure, the inflammatory response, collagen levels, and antioxidant markers in rat lung tissues were significantly improved by PFD, and these effects were improved by combination with LOS. The findings of this in vivo study suggest that the combined administration of PFD and LOS may provide more potent protection against IPF than single therapy through boosting its anti-inflammatory, anti-fibrotic, and anti-oxidant effects. These results hold promise in developing a more effective therapeutic strategy for treating of lung fibrosis.

D-limonene inhibits peritoneal adhesion formation in rats via anti-inflammatory, anti-angiogenic, and antioxidative effects

The aim of this research was to investigate the effects of D-limonene on decreasing post-operative adhesion in rats and to understand the mechanisms involved. Peritoneal adhesions were induced by creating different incisions and excising a 1 × 1 cm section of the peritoneum. The experimental groups included a sham group, a control group in which peritoneal adhesions were induced without any treatment, and two treatment groups in which animals received D-limonene with dosages of 25 and 50 mg/kg after inducing peritoneal adhesions. Macroscopic examination of adhesions showed that both treatment groups had reduced adhesion bands in comparison to the control group. Immunohistochemical assessment of TGF-β1, TNF-α, and VEGF on day 14 revealed a significant increment in the level of immunopositive cells for the mentioned markers in the control group, whereas administration of limonene in both doses significantly reduced levels of TGF-β1, TNF-α, and VEGF (P < 0.05). Induction of peritoneal adhesions in the control group significantly increased TGF-β1, TNF-α, and VEGF on days 3 and 14 in western blot evaluation, while treatment with limonene significantly reduced TNF-α level on day 14 (P < 0.05). Moreover, VEGF levels in both treatment groups significantly reduced on days 3 and 14. In the control group, a significant increment in the levels of MDA and NO and a notable decline in the levels of GPX, CAT was observed (P < 0.05). Limonene 50 group significantly reduced MDA level and increased GPx and CAT levels on day 14 (P < 0.05). In summary, D-limonene reduced adhesion bands, inflammatory cytokines, angiogenesis, and oxidative stress.

A Zwitterionic Hydrogel with Anti-Oxidative and Anti-Inflammatory Properties for the Prevention of Peritoneal Adhesion by Inhibiting Mesothelial-Mesenchymal Transition

Postoperative peritoneal adhesion is a serious clinical complication. Various hydrogel barriers have been developed to prevent peritoneal adhesion. However, it remains a challenge to design a hydrogel with desirable physicochemical properties and bioactivities. In this study, a zwitterionic polysaccharide-based multifunctional hydrogel is developed using epigallocatechin-3-gallate (EGCG) to prevent postoperative abdominal adhesion. This hydrogel is simple to use and has desirable properties, such as excellent injectability, self-healing, and non-swelling properties. The hydrogel also has ultralow fouling capabilities, such as superior bactericidal performance, cell and protein adhesion, and low immunogenicity resistance. Moreover, the hydrogel exhibits good antioxidant activity, which is attributed to the integration of EGCG. Furthermore, the detailed mechanism from in vivo and in vitro experimental studies illustrates that hydrogel compositions can synergistically prevent adhesion formation through multiple pathways, including anti-inflammatory and antioxidant capabilities and inhibition effects on the mesothelial-mesenchymal transition (MMT) process induced by transforming growth factor (TGF-β). In summary, this zwitterionic multifunctional hydrogel has great potential to prevent postoperative adhesion formation in the clinical setting.

Techniques for navigating postsurgical adhesions: Insights into mechanisms and future directions

Postsurgical adhesions are a common complication of surgical procedures that can lead to postoperative pain, bowel obstruction, infertility, as well as complications with future procedures. Several agents have been developed to prevent adhesion formation, such as barriers, anti-inflammatory and fibrinolytic agents. The Food and Drug Administration (FDA) has approved the use of physical barrier agents, but they have been associated with conflicting clinical studies and controversy in the clinical utilization of anti-adhesion barriers. In this review, we summarize the human anatomy of the peritoneum, the pathophysiology of adhesion formation, the current prevention agents, as well as the current research progress on adhesion prevention. The early cellular events starting with injured mesothelial cells and incorporating macrophage response have recently been found to be associated with adhesion formation. This may provide the key component for developing future adhesion prevention methods. The current use of physical barriers to separate tissues, such as Seprafilm®, composed of hyaluronic acid and carboxymethylcellulose, can only reduce the risk of adhesion formation at the end stage. Other anti-inflammatory or fibrinolytic agents for preventing adhesions have only been studied within the context of current research models, which is limited by the lack of in-vitro model systems as well as in-depth study of in-vivo models to evaluate the efficiency of anti-adhesion agents. In addition, we explore emerging therapies, such as gene therapy and stem cell-based approaches, that may offer new strategies for preventing adhesion formation. In conclusion, anti-adhesion agents represent a promising approach for reducing the burden of adhesion-related complications in surgical patients. Further research is needed to optimize their use and develop new therapies for this challenging clinical problem.

Prevention strategies of postoperative adhesion in soft tissues by applying biomaterials: Based on the mechanisms of occurrence and development of adhesions

Postoperative adhesion (POA) widely occurs in soft tissues and usually leads to chronic pain, dysfunction of adjacent organs and some acute complications, seriously reducing patients' quality of life and even being life-threatening. Except for adhesiolysis, there are few effective methods to release existing adhesion. However, it requires a second operation and inpatient care and usually triggers recurrent adhesion in a great incidence. Hence, preventing POA formation has been regarded as the most effective clinical strategy. Biomaterials have attracted great attention in preventing POA because they can act as both barriers and drug carriers. Nevertheless, even though much reported research has been demonstrated their efficacy on POA inhibition to a certain extent, thoroughly preventing POA formation is still challenging. Meanwhile, most biomaterials for POA prevention were designed based on limited experiences, not a solid theoretical basis, showing blindness. Hence, we aimed to provide guidance for designing anti-adhesion materials applied in different soft tissues based on the mechanisms of POA occurrence and development. We first classified the postoperative adhesions into four categories according to the different components of diverse adhesion tissues, and named them as "membranous adhesion", "vascular adhesion", "adhesive adhesion" and "scarred adhesion", respectively. Then, the process of the occurrence and development of POA were analyzed, and the main influencing factors in different stages were clarified. Further, we proposed seven strategies for POA prevention by using biomaterials according to these influencing factors. Meanwhile, the relevant practices were summarized according to the corresponding strategies and the future perspectives were analyzed.

Herbal formula Jiawei Xiaochengqi decoction prevents postoperative abdominal adhesion in a rat model through inhibition of CXCL2-CXCR2 pathway

BACKGROUND

Postoperative abdominal adhesion (PAA) is the most common complication after abdominal surgeries, which can lead to intestinal obstruction, chronic abdominal pain or female infertility. Jiawei Xiaochengqi decoction (JWXCQ) is a hospital preparation widely used for PAA treatment in Nanfang Hospital of Southern Medical University for more than twenty years.

PURPOSE

This study aimed to investigate the therapeutic effects and potential mechanism of JWXCQ against PAA and provide beneficial information for its clinical application.

METHODS

The main active components of JWXCQ were identified using ultra high performance liquid chromatography (UHPLC) combined with standard substance comparison. The efficacy and underlying mechanism of JWXCQ were evaluated through in vivo experiments with a postsurgical-induced peritoneal adhesion rat model, and in vitro studies with LPS-stimulated Raw 264.7 macrophages and primary fibroblasts. H&E and Masson staining were performed to assess histopathological changes. The levels of cytokines/proteins-associated with inflammation and degradation of extracellular matrix as well as CXCL2-CXCR2 pathway-related proteins were determined by ELISA, qRT-PCR, western blot assays or immunohistochemistry, respectively. Furthermore, siCXCR2 transfection was used to validate the mechanism of action of JWXCQ.

RESULTS

JWXCQ treatment significantly reduced the formation of PAA, inhibited the inflammation and collagen deposition, and facilitated the secretion of MMP9, decreased the levels of IL-1β, IL-6, TIMP1, COL-1, and suppressed the CXCL2-CXCR2 pathway in PAA rats. Furthermore, JWXCQ inhibited its downstream pathways, the JAK2-STAT3 and PI3K-AKT signaling, as indicated by the suppression of the phosphorylation levels of STAT3 and AKT. In vitro cell experiments revealed that JWXCQ reduced IL-1β and IL-6 secretion in Raw 264.7 macrophages and COL-1 in primary fibroblasts. The CXCL2-CXCR2, JAK2-STAT3 and PI3K-AKT pathways were also inhibited after JWXCQ treatment, which were consistent with the in vivo results. More importantly, silence of CXCR2 eliminated the regulatory effects of JWXCQ.

CONCLUSION

JWXCQ could effectively prevent the PAA formation by alleviating inflammation and collagen deposition, which was associated with the inhibition of CXCL2-CXCR2 pathway. This study investigated the relevant pharmacological mechanisms of JWXCQ, providing further evidence for the application of JWXCQ in clinical PAA treatment.

The Therapeutic Potential of Targeting Key Signaling Pathways as a Novel Approach to Ameliorating Post-Surgical Adhesions

BACKGROUND

Peritoneal adhesions (PA) are a common complication of abdominal operations. A growing body of evidence shows that inhibition of inflammation and fibrosis at sites of peritoneal damaging could prevent the development of intra-abdominal adhesions.

METHODS

A search of PubMed, Medline, CINAHL and Embase databases was performed using the keywords 'postsurgical adhesion', 'post-operative adhesion', 'peritoneal adhesion', 'surgery-induced adhesion' and 'abdominal adhesion'. Studies detailing the use of pharmacological and non-pharmacological agents for peritoneal adhesion prevention were identified, and their bibliographies were thoroughly reviewed to identify further related articles.

RESULTS

Several signaling pathways, such as tumor necrosis factor-alpha, tissue plasminogen activator, and type 1 plasminogen activator inhibitor, macrophages, fibroblasts, and mesothelial cells play a key part in the development of plasminogen activator. Several therapeutic approaches based on anti-PA drug barriers and traditional herbal medicines have been developed to prevent and treat adhesion formation. In recent years, the most promising method to prevent PA is treatment using biomaterial-based barriers.

CONCLUSION

In this review, we provide an overview of the pathophysiology of adhesion formation and various agents targeting different pathways, including chemical agents, herbal agents, physical barriers, and clinical trials concerning this matter.

Rosmarinic acid prevents post-operative abdominal adhesions in a rat model

This study aims to determine the effects of rosmarinic acid which involved the mechanisms to decrease the postoperative peritoneal adhesion formation in rats. Various incisions and removing a 1 × 1 cm piece of peritoneum was used to induce the peritoneal adhesions. Experimental groups were as follows: 1-Sham group. 2-Control group: Peritoneal adhesions were induced and no treatments were performed. 3-Treatment groups: Following inducing peritoneal adhesions, animals received rosmarinic acid with 50 and 70 mg/kg dosage, respectively. Macroscopic examination of adhesions indicated that adhesion bands were reduced in both treatment groups compared to the control group. Moreover, the adhesion score was decreased in both treatment groups on day 14. Inflammation and fibroblast proliferation were both reduced in the treatment groups on day 14. TGF-β1, TNF-α, and VEGF were all evaluated by western blot and immunohistochemistry on days 3 and 14. Treatment groups reduced inflammatory cytokines on days 3 and 14. The treatment group with a 70 mg/kg dosage decreased TGF-β1 and TNF-α levels more than the other treatment group. The administration of rosmarinic acid significantly reduced MDA and increased CAT levels. In conclusion, the rosmarinic acid was effective to reduce the adhesion bands, inflammatory cytokines, angiogenesis, and oxidative stress.

Indomethacin Sustained-Release Anti-adhesion Membrane Composed of a Phospholipid and Polycaprolactone Blend

Background

Postoperative peritoneal adhesions are among common challenging problems in surgery. The availability of limited efficient strategies to prevent intra-abdominal adhesion reinforces the need to explore new methods. Given the favorable prolonged drug release characteristics of polycaprolactone (PCL) films and their ability to act as a biodegradable physical barrier implant, along with the anti-inflammatory and anti-adhesion properties of indomethacin and phospholipids, this study hypothesized that indomethacin sustained-release membrane composed of phosphatidylcholine (PC) and PCL blend could efficiently prevent abdominal adhesion formation.

Methods

Different polymeric and polymeric/lipidic hybrid formulations with three feeding materials to drug weight ratios were prepared, and their physicochemical characteristics and drug release kinetics were evaluated and compared. Abdominal adhesions were induced in 48 rats by the abrasion of the cecum and excision of a section of the opposite abdominal wall. Adhesion formation was evaluated by macroscopic scoring, histological, scanning electron microscopy, and polymerase chain reaction analyses.

Results

Both PCL and PCL-PC films exhibited sustained indomethacin release profiles. The X-ray diffraction and Fourier-transform infrared spectroscopy studies confirmed indomethacin incorporation in formulations in molecular dispersion form without any interaction. The films showed smooth surfaces and good mechanical properties. The treatment with indomethacin PCL-PC membrane significantly reduced the expression levels of tumor necrosis factor-alpha, transforming growth factor-beta, interleukin-1, interleukin-6, and fibrinogen in the adhesion tissues. The separation of the injured peritoneum, very low adhesion scores, and complete mesothelial cell regeneration were also achieved.

Conclusions

This study suggests that indomethacin-eluting PCL-PC membrane acting through the combination of physical barrier, anti-inflammatory agents, and controlled drug delivery warrants an effective approach to prevent intra-abdominal adhesion.

Intraperitoneal Lavage with Crocus sativus Prevents Postoperative-Induced Peritoneal Adhesion in a Rat Model: Evidence from Animal and Cellular Studies

Postoperative peritoneal adhesions are considered the major complication following abdominal surgeries. The primary clinical complications of peritoneal adhesion are intestinal obstruction, infertility, pelvic pain, and postoperative mortality. In this study, regarding the anti-inflammatory and antioxidant activities of Crocus sativus, we aimed to evaluate the effects of Crocus sativus on the prevention of postsurgical-induced peritoneal adhesion. Male Wistar-Albino rats were used to investigate the preventive effects of C. sativus extract (0.5%, 0.25% and 0.125% w/v) against postsurgical-induced peritoneal adhesion compared to pirfenidone (PFD, 7.5% w/v). We also investigated the protective effects of PFD (100 μg/ml) and C. sativus extract (100, 200, and 400 μg/ml) in TGF-β1-induced fibrotic macrophage polarization. The levels of cell proliferation and oxidative, antioxidative, inflammatory and anti-inflammatory, fibrosis, and angiogenesis biomarkers were evaluated both in vivo and in vitro models. C. sativus extract ameliorates postoperational-induced peritoneal adhesion development by attenuating oxidative stress [malondialdehyde (MDA)]; inflammatory mediators [interleukin- (IL-) 6, tumour necrosis factor- (TNF-) α, and prostaglandin E₂ (PGE₂)]; fibrosis [transforming growth factor- (TGF-) β1, IL-4, and plasminogen activator inhibitor (PAI)]; and angiogenesis [vascular endothelial growth factor (VEGF)] markers, while propagating antioxidant [glutathione (GSH)], anti-inflammatory (IL-10), and fibrinolytic [tissue plasminogen activator (tPA)] markers and tPA/PAI ratio. In a cellular model, we revealed that the extract, without any toxicity, regulated the levels of cell proliferation and inflammatory (TNF-α), angiogenesis (VEGF), anti-inflammatory (IL-10), M1 [inducible nitric oxide synthase (iNOS)] and M2 [arginase-1 (Arg 1)] biomarkers, and iNOS/Arg-1 ratio towards antifibrotic M1 phenotype of macrophage, in a concentration-dependent manner. Taken together, the current study indicated that C. sativus reduces peritoneal adhesion formation by modulating the macrophage polarization from M2 towards M1 cells.

Prevention of Post-Operative Adhesions: A Comprehensive Review of Present and Emerging Strategies

Post-operative adhesions affect patients undergoing all types of surgeries. They are associated with serious complications, including higher risk of morbidity and mortality. Given increased hospitalization, longer operative times, and longer length of hospital stay, post-surgical adhesions also pose a great financial burden. Although our knowledge of some of the underlying mechanisms driving adhesion formation has significantly improved over the past two decades, literature has yet to fully explain the pathogenesis and etiology of post-surgical adhesions. As a result, finding an ideal preventative strategy and leveraging appropriate tissue engineering strategies has proven to be difficult. Different products have been developed and enjoyed various levels of success along the translational tissue engineering research spectrum, but their clinical translation has been limited. Herein, we comprehensively review the agents and products that have been developed to mitigate post-operative adhesion formation. We also assess emerging strategies that aid in facilitating precision and personalized medicine to improve outcomes for patients and our healthcare system.

Salvia miltiorrhiza hydroalcoholic extract inhibits postoperative peritoneal adhesions in rats

Background

One of the most prevalent postoperative complications is believed to be intra-abdominal peritoneal adhesions, which is followed by several complications. Several adhesion prevention products have been examined, yet none of them were found to be completely effective. The current research is conducted to evaluate the beneficial effects of Salvia miltiorrhiza hydroalcoholic extract in inhibiting postoperative peritoneal adhesions in rats.

Methods

Forty rats were randomly classified into five equal groups (n = 8): 1) the normal group did not undergo surgical operations, 2) the control group in which the adhesion was induced, and which did not receive any treatment, 3) distilled water group that received distilled water, and 4,5) treatment groups treated with 1 and 5% of Salvia miltiorrhiza hydroalcoholic extract. The rats were euthanized 14 days following the surgery and the macroscopic score, the microscopic score of granulomatous inflammation and granulation tissue formation, IHC markers (vimentin, CD31, IL-1β, COX-2, and iNOS), and oxidative stress biomarkers (MDA, GPx, CAT, and TAC) were assessed in the experimental groups of the study.

Results

The difference between the control group and other groups for the adhesions macroscopic score, microscopic score, IHC markers, and oxidative stress biomarkers was significant (p < 0.05). Distilled water had no protective effect on the formation of peritoneal adhesions. Salvia miltiorrhiza treatment in two different doses significantly reduced macroscopic and microscopic scores, MDA concentration, Vimentin, IL-1β, COX-2, and iNOS compared to the control group (p < 0.05). The levels of GPx, CAT, and TAC in the treatment groups increased significantly compared with the control group (p < 0.05). Our findings revealed that a higher dose of Salvia miltiorrhiza was more effective in reducing peritoneal adhesions, proinflammatory and mesenchymal cell markers, and oxidative stress.

Conclusions

Salvia miltiorrhiza extract, owing to its strong antioxidant and anti-inflammatory properties, could effectively reduce peritoneal adhesions. Therefore, Salvia miltiorrhiza is recommended to be used as an effective anti-peritoneal post-operative adhesive agent.

Tumor necrosis factor α, protein gene product 9.5, matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 presence in congenital intra-abdominal adhesions in children under one year of age

INTRODUCTION

The regulatory role of cytokines and extracellular matrix remodeling factors in congenital intra-abdominal adhesions has not yet been defined. The aim of this study was to assess the presence and relative distribution of tumor necrosis factor α (TNF-α), protein gene product 9.5 (PGP 9.5), matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in adhesions.

MATERIAL AND METHODS

TNF-α, PGP 9.5, MMP-2 and TIMP-2 were detected using immunohistochemical methods and their relative distribution was evaluated by means of the semiquantitative counting method. The results were analyzed using non-parametric statistical methods.

RESULTS

A moderate number of TNF-α positive macrophages and fibroblasts was found. A positive correlation was observed between the immunoreactive structures for TNF-α and PGP 9.5. A positive reaction for PGP 9.5 was observed in nerve fibers and shape modified fibroblasts. In control group tissues, positive structures were seen in significantly higher counts for PGP 9.5. Few to moderate numbers of MMP-2 positive macrophages, epithelioid cells, fibroblasts and endotheliocytes were detected. There was no significant difference between the groups. A positive reaction for TIMP-2 was seen in fibroblasts, macrophages and endotheliocytes. In control group tissues, positive structures were found in significantly higher counts for TIMP-2.

CONCLUSIONS

The positive correlation between the immunoreactive structures for TNF-α and PGP 9.5 suggests that nerve in-growth into intraabdominal adhesions might be induced by TNF-α and PGP 9.5 could have a role in maintaining inflammation. The down-regulation of PGP 9.5 suggests that pathogenesis of congenital intraabdominal adhesions may be related to hypoxia induced damage. The imbalance between MMP-2 and TIMP-2 may prove tissue fibrosis as a response to congenital peritoneal adhesions.

Postoperative peritoneal adhesion: an update on physiopathology and novel traditional herbal and modern medical therapeutics

Postoperative peritoneal adhesion (PPA) is a serious clinical condition that affects the high percentage of patients after abdominal surgery. In this review, we have tried to focus on pathophysiology and different underlying signal pathways of adhesion formation based on recent progress in the molecular and cellular mechanisms. Also, the strategies, developed based on traditional herbal and modern medicines, to prevent and treat the PPA via regulation of the molecular mechanisms were investigated. The search engines such as Google Scholar, PubMed, Scopus, and Science Direct have been used to evaluate the current literature related to the pathogenesis of adhesion formation and novel products. Recently, different mechanisms have been defined for adhesion formation, mainly categorized in fibrin formation and adhesion fibroblast function, inflammation, and angiogenesis. Therefore, the suppression of these mechanisms via traditional and modern medicine has been suggested in several studies. While different strategies with encouraging findings have been developed, most of the studies showed contradictory results and were performed on animals. The herbal products have been introduced as safe and effective agent which can be considered in future preclinical and clinical studies. Although a wide range of therapeutics based on traditional and modern medicines have been suggested, there is no agreement in the efficacy of these methods to prevent or treat adhesion formation after surgeries. Further basic and clinical researches are still needed to propose the efficiency of recommended strategies for prevention and treatment of PPA.

Berberine prevents primary peritoneal adhesion and adhesion reformation by directly inhibiting TIMP-1

Peritoneal adhesions are fibrous tissues that tether organs to one another or to the peritoneal wall and represent the major cause of postsurgical morbidity. Enterolysis at repeat surgeries induces adhesion reformation that is more difficult to prevent than primary adhesion. Here we studied the preventive effects of different approaches of berberine treatment for primary adhesion, and its effects on adhesion reformation compared to Interceed. We found the primary adhesion was remarkably prevented by berberine through intraperitoneal injection 30 min before abrasive surgery (pre-berberine) or direct addition into injured cecum immediately after the surgery (inter-berberine). Rats with adhesion reformation had a more deteriorative collagen accumulation and tissue injury in abrasive sites than rats with primary adhesion. The dysregulated TIMP-1/MMP balance was observed in patients after surgery, as well as adhesion tissues from primary adhesion or adhesion reformation rats. Inter-berberine treatment had a better effect for adhesion reformation prevention than Interceed. Berberine promoted the activation of MMP-3 and MMP-8 by directly blocking TIMP-1 activation core, which was reversed by TIMP-1 overexpression in fibroblasts. In conclusion, this study suggests berberine as a reasonable approach for preventing primary adhesion formation and adhesion reformation.

Encapsulating Peritoneal Sclerosis: Pathophysiology and Current Treatment Options

Encapsulating peritoneal sclerosis (EPS) is a life-threatening complication of long-term peritoneal dialysis (PD), which may even occur after patients have switched to hemodialysis (HD) or undergone kidney transplantation. The incidence of EPS varies across the globe and increases with PD vintage. Causative factors are the chronic exposure to bioincompatible PD solutions, which cause long-term modifications of the peritoneum, a high peritoneal transporter status involving high glucose concentrations, peritonitis episodes, and smoldering peritoneal inflammation. Additional potential causes are predisposing genetic factors and some medications. Clinical symptoms comprise signs of intestinal obstruction and a high peritoneal transporter status with incipient ultrafiltration failure. In radiological, macro-, and microscopic studies, a massively fibrotic and calcified peritoneum enclosed the intestine and parietal wall in such cases. Empirical treatments commonly used are corticosteroids and tamoxifen, which has fibrinolytic properties. Immunosuppressants like azathioprine, mycophenolate mofetil, or mTOR inhibitors may also help with reducing inflammation, fibrin deposition, and collagen synthesis and maturation. In animal studies, N-acetylcysteine, colchicine, rosiglitazone, thalidomide, and renin-angiotensin system (RAS) inhibitors yielded promising results. Surgical treatment has mainly been performed in severe cases of intestinal obstruction, with varying results. Mortality rates are still 25–55% in adults and about 14% in children. To reduce the incidence of EPS and improve the outcome of this devastating complication of chronic PD, vigorous consideration of the risk factors, early diagnosis, and timely discontinuation of PD and therapeutic interventions are mandatory, even though these are merely based on empirical evidence.

The Morphopathogenetic Aspects of Intraabdominal Adhesions in Children under One Year of Age

Background and Objectives: The morphopathogenesis of adhesions is a complex process, characterized by the accumulation of an extracellular matrix, inflammation and hypoxia. The regulatory role between morphopathogenic factors in adhesions has not yet been defined. The aim was to investigate the appearance of transforming growth factor beta (TGFβ), basic fibroblast growth factor (FGF-2), fibroblast growth factor receptor 1 (FGFR1), protein gene product 9.5 (PGP 9.5), chromogranin A (CgA), interleukin-1 alpha (IL-1α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-7 (IL-7), interleukin-8 (IL-8), interleukin-10 (IL-10), tumor necrosis factor alpha (TNFα), matrix metaloproteinase-2 (MMP-2) and matrix metaloproteinase-2 tissue inhibitor (TIMP-2) in intraabdominal adhesions. Materials and Methods: The study material was obtained from 49 patients under one year of age with total or partial bowel obstruction. All factors were detected using immunohistochemistry methods and their relative distribution was evaluated by means of the semiquantitative counting method. Results: Intraabdominal adhesions are characterized by increased TGFβ, FGFR1 and decreased FGF-2, PGP 9.5, IL-1, IL-4, IL-8, TIMP-2 findings. The most significant changes observed were the remodulation of the extracellular matrix, promotion of neoangiogenesis and the maintenance of a prolonged inflammation. Conclusions: The increase in TGFβ, as well as the disbalance between MMP-2 and TIMP-2 proves an increased fibrosis in intraabdominal adhesions. Less detected FGF-2 and more prominent FGR1 findings points out a compensatory receptor stimulation in response to the lacking same factor. The decrease in PGP 9.5 indicate hypoxic injury and proves the stimulation of neoangiogenesis. An unpronounced IL-1 and marked IL-10 finding indicate the local tissue protection reaction, the decrease in IL-4 could be the direct cause of giant cells, but the decrease of IL-8 could confirm a delayed chemotaxis of inflammatory cells.

Ligustrazine nanoparticles nano spray's activation on Nrf2/ARE pathway in oxidative stress injury in rats with postoperative abdominal adhesion

Background

Postoperative abdominal adhesions formation is considered a significant clinical entity implicating the healing process following major pelvic and abdominal surgery, with serious clinical complications and need for substantial health care expenditures. However, setting a physical barrier between the damage site and the neighboring tissues is a convenient and highly valid way to minimize or prevent peritoneal adhesions. The present experimental study evaluated the preventive effect of ligustrazine nanoparticles nano spray (LNNS) on postoperative abdominal adhesion in rats and explored its mechanism.

Methods

Sixty male Sprague Dawley (SD) rats were randomly divided into sham operation group, control group, sodium hyaluronate group and low, medium, and high dose LNNS groups. All groups were prepared with abdominal adhesion models except for the sham operation group. The models were made by opening the abdominal cavity to and filing the serosa in ileocecal junction. The abdominal cavity of rats in the sham operation group were only opened and sutured. The wound surface of rats in the sodium hyaluronate group, low, medium, and high dose LNNS groups were sprayed with sodium hyaluronate gel (0.5 mL/kg) and LNNS (2.5, 5, and 10 mL/kg). Rats in each group were sacrificed 7 days later. Degree of adhesion was evaluated by naked eyes and the pathological sections were scored afterwards. The collagen synthesis in adhesion tissues was detected by Masson's trichrome stain, and the activities of reactive oxygen species (ROS), nitric oxide (NO), superoxide dismutase (SOD) and malondialdehyde (MDA) in peritoneal fluid were detected with the method of chromogenic substrate. Levels of TNF-α and IL-1β in serum, and the protein levels of MCP-1 and MMP-9 in adhesion tissues were detected by ELISA and. immunohistochemistry respectively. RT-PCR and Western blot were utilized to identify the expression levels of Nrf2, heme-oxygenase-1, NQO1 mRNA and protein in adherent intestinal tissues.

Results

Compared with the control group, the incidence of postoperative abdominal adhesions decreased in the low, medium and high dose LNNS groups, while the expression of SOD in the peritoneal fluid significantly increased. The expression levels of ROS, MDA and NO were reduced remarkably (P<0.05), so were the expression levels of serum TNF-α and IL-1β (P<0.01) and the expression of MCP-1 protein in adhesion tissues. The MMP-9 protein expression, and Nrf2, heme-oxygenase-1, NQO1 mRNA and protein expressions increased.

Conclusions

LNNS with medium or high dose can significantly reduce the incidence of postoperative abdominal adhesions, the mechanism of which may be the activation of Nrf2/ARE pathway, resulting in the up-regulation of Nrf2, heme-oxygenase-1, NQO1 and mRNA expression, as well as the levels of TNF-α and IL-1β in peripheral blood and the expression of MCP-1 protein in adhesion tissues. Meanwhile, the content of MMP-9 protein in adhesion tissues were raised, and oxidative stress and inflammatory response are released.

The Prevention of Hepatectomy-Induced Adhesions by Bilayer Sponge Composed of Ultrapure Alginate

BACKGROUND

Adhesion formation is a critical issue in surgery, particularly in hepatectomy. The present study aimed to develop a bilayer adhesion barrier comprising alginate (Alg) of different molecular weight (Mw). It was expected that a slowly dissolving layer remains on the cut surface, functioning as a physical barrier, whereas a rapidly dissolving layer widely distributes in the peritoneal cavity to prevent de novo adhesions.

METHODS

Bilayer Alg sponges were fabricated using low Mw Alg for the upper layer and high Mw Alg for the bottom layer. The dissolution behavior of each layer was evaluated in vitro in peritoneum-like environments. We constructed a Pean crush hepatectomy-induced adhesion model in rats. The effects of the bilayer sponge on cut surface and de novo adhesions were separately evaluated in terms of their extent and grade.

RESULTS

The Alg sponge layer with low Mw dissolved faster than that with high Mw in vitro. One week after the hepatectomy, although no significant decrease in adhesion extent on the cut surface was observed in rats that received Seprafilm and Interceed, treatment with Alg bilayer sponge significantly decreased the adhesion extent to 38% of that without treatment. Moreover, a significant decrease in de novo adhesion extent was observed in the Alg bilayer sponge compared with the Interceed group.

CONCLUSIONS

The Alg bilayer sponge was effective for preventing both cut surface and de novo adhesions in the rat Pean crush hepatectomy model. The simple yet functional design of the Alg bilayer sponge can facilitate its use in future clinical practice.

Battling adhesions: from understanding to prevention

Adhesions represent a major burden in clinical practice, particularly following abdominal, intrauterine, pericardial and tendon surgical procedures. Adhesions are initiated by a disruption in the epithelial or mesothelial layer of tissue, which leads to fibrin adhesion sites due to the downregulation of fibrinolytic activity and an increase in fibrin deposition. Hence, the metabolic events involved in tissue healing, coagulation, inflammation, fibrinolysis and angiogenesis play a pivotal role in adhesion formation. Understanding these events, their interactions and their influence on the development of post-surgical adhesion is crucial for the development of effective therapies to prevent them. Mechanical barriers, antiadhesive agents and combination thereof are customarily used in the battle against adhesions. Although these systems seem to be effective at reducing adhesions in clinical procedures, their prevention remains still elusive, imposing the need for new antiadhesive strategies.

The sticky business of adhesion prevention in minimally invasive gynecologic surgery

PURPOSE OF REVIEW

The negative impact of postoperative adhesions has long been recognized, but available options for prevention remain limited. Minimally invasive surgery is associated with decreased adhesion formation due to meticulous dissection with gentile tissue handling, improved hemostasis, and limiting exposure to reactive foreign material; however, there is conflicting evidence on the clinical significance of adhesion-related disease when compared to open surgery. Laparoscopic surgery does not guarantee the prevention of adhesions because longer operative times and high insufflation pressure can promote adhesion formation. Adhesion barriers have been available since the 1980s, but uptake among surgeons remains low and there is no clear evidence that they reduce clinically significant outcomes such as chronic pain or infertility. In this article, we review the ongoing magnitude of adhesion-related complications in gynecologic surgery, currently available interventions and new research toward more effective adhesion prevention.

RECENT FINDINGS

Recent literature provides updated epidemiologic data and estimates of healthcare costs associated with adhesion-related complications. There have been important advances in our understanding of normal peritoneal healing and the pathophysiology of adhesions. Adhesion barriers continue to be tested for safety and effectiveness and new agents have shown promise in clinical studies. Finally, there are many experimental studies of new materials and pharmacologic and biologic prevention agents.

SUMMARY

There is great interest in new adhesion prevention technologies, but new agents are unlikely to be available for clinical use for many years. High-quality effectiveness and outcomes-related research is still needed.

Pirfenidone protects against paraquat-induced lung injury and fibrosis in mice by modulation of inflammation, oxidative stress, and gene expression

In this study we investigated the protective effects and possible mechanisms of pirfenidone (PF) in paraquat (PQ)-induced lung injury and fibrosis in mice. Lung injury was induced by injection of PQ (20 mg/kg). Thereafter, mice orally received water and PF (100 and 200 mg/kg) for four weeks. After 28 days, the inflammation and fibrosis were determined in the lungs by analysis of histopathology, bronchoalveolar lavage fluid (BALF) cell count, lung wet/dry weight ratio, hydroxyproline content, and oxidative stress biomarkers. Expression of several genes involved in fibrogenesis and modulation of reactive oxygen species (ROS) production, such as TGF-β1, α-SMA, collagen Iα and IV, NOX1, NOX4, iNOS, and GPX1 were determined using RT-qPCR. PF significantly decreased the lung fibrosis and edema, inflammatory cells infiltration, TGF-β1 concentration, and amount of hydroxyproline in the lung tissue. PF dose-dependently improved the expression level of the studied genes to the near normal. Decreasing of lung lipid peroxidation and catalase activity, and increasing of SOD activity in the treated mice were significant compared to the control group. Pirfenidone ameliorate paraquat induced lung injury and fibrosis partly through inhibition of inflammation and oxidative stress, and downregulation of genes encoding for profibrotic cytokines and enzymatic systems for ROS production.

Effect of Emodin on Preventing Postoperative Intra-Abdominal Adhesion Formation

BACKGROUND

Postoperative intra-abdominal adhesions are a major complication after abdominal surgery. Although various methods have been used to prevent and treat adhesions, the effects have not been satisfactory. Emodin, a naturally occurring anthraquinone derivative and an active ingredient in traditional Chinese herbs, exhibits a variety of pharmacological effects. In our study, we demonstrated the effect of emodin treatment on preventing postoperative adhesion formation.

MATERIALS AND METHODS

A total of 48 rats were divided into six groups. Abdominal adhesions were created by abrasion of the cecum and its opposite abdominal wall. In the experimental groups, the rats were administered daily oral doses of emodin. On the seventh day after operation, the rats were euthanized, and blood and pathological specimens were collected. Abdominal adhesion formation was evaluated by necropsy, pathology, immunohistochemistry, Western blot, and enzyme-linked immunosorbent assay analyses.

RESULTS

Abdominal adhesions were markedly reduced by emodin treatment. Compared with the control group, collagen deposition was reduced and the peritoneal mesothelial completeness rate was higher in the emodin-treated groups. Emodin had anti-inflammatory effects, reduced oxidative stress, and promoted the movement of the intestinal tract (P < 0.05).

CONCLUSION

Emodin significantly reduced intra-abdominal adhesion formation in a rat model.

Pirfenidone Accelerates Wound Healing in Chronic Diabetic Foot Ulcers: A Randomized, Double-Blind Controlled Trial

BACKGROUND

Diabetic foot ulcers are one disabling complication of diabetes mellitus. Pirfenidone (PFD) is a potent modulator of extracellular matrix. Modified diallyl disulfide oxide (M-DDO) is an antimicrobial and antiseptic agent.

AIM

To evaluate efficacy of topical PFD + M-DDO in a randomized, double-blind trial versus ketanserin in the treatment of noninfected chronic DFU.

METHODS

Patients received PFD + M-DDO or ketanserin for 6 months. Relative ulcer volume (RUV) was measured every month; biopsies were taken at baseline and months 1 and 2 for histopathology and gene expression analysis for COL-1α, COL-4, KGF, VEGF, ACTA2 (α-SMA), elastin, fibronectin, TGF-β1, TGF-β3, HIF-1α, and HIF-1β.

RESULTS

Reduction of median RUV in the PFD + M-DDO group was 62%, 89.8%, and 99.7% at months 1-3 and 100% from months 4 to 6. Ketanserin reduced RUV in 38.4%, 56%, 60.8%, 94%, 94.8%, and 100% from the first to the sixth month, respectively. Healing score improved 4.5 points with PFD + M-DDO and 1.5 points with ketanserin compared to basal value. Histology analysis revealed few inflammatory cells and organized/ordered collagen fiber bundles in PFD + M-DDO. Expression of most genes was increased with PFD + M-DDO; 43.8% of ulcers were resolved using PFD + M-DDO and 23.5% with ketanserin.

CONCLUSION

PFD + M-DDO was more effective than ketanserin in RUV reduction.

Pirfenidone ameliorates concanavalin A-induced hepatitis in mice via modulation of reactive oxygen species/nuclear factor kappa B signalling pathways

Objectives

This study aimed to evaluate the potential protective effects of pirfenidone (PFD) against concanavalin A (Con A)-induced hepatitis in mice.

Methods

Autoimmune model of hepatitis was established using single intravenous injection of Con A. Mice were randomly assigned into four groups as follows: control group; Con A group; and two groups, receiving PFD in two dose levels (200, 300 mg/kg) for 5 days before Con A administration. Extent of hepatitis was studied using biochemical, histopathological and immunohistochemical estimations.

Key findings

Hepatitis was clearly evident through extensive hepatocellular lesions and elevated levels of serum transaminases, alkaline phosphatase and lactate dehydrogenase. Con A induced an imbalance between oxidant and antioxidant status in the hepatic tissue. Furthermore, Con A significantly elevated hepatic nuclear factor kappa B (NF-κB) expression and inflammatory cytokines levels (tumour necrosis factor-alpha, interleukin-6 and nitric oxide). PFD pretreatment potently ameliorated all these pathological changes.

Conclusions

Pirfenidone hepatoprotective activity may be mediated through its antioxidant ability that suppresses NF-κB activation signalling pathways suggesting that PFD may be a new candidate for treatment of acute hepatitis.

Preparation of novel pirfenidone microspheres for lung-targeted delivery: in vitro and in vivo study

The aim of this study was to develop and characterize pirfenidone (PF)-loaded chitosan microspheres for lung targeting. The microspheres were prepared using the emulsion-solvent evaporation method and characterized by assessing morphology, particle size, and zeta potential. The microspheres had a spherical nature with highly smooth and integrated surfaces. The particle size of microspheres was 4.6±0.3 µm, and the zeta potential was 20.3±1.4 mV. The in vitro release results indicated that the obtained formulation of PF could reach the state of sustained release with a biphasic drug release pattern. It was observed that there was no significant difference in both the percentage of entrapment efficiency and that of drug release before and after the stability study. In vivo, the calculated relative bioavailability indicated greater pulmonary absorption of PF when it was encapsulated in microspheres. According to histopathological studies, no histological change occurred to the rat lung after the administration of PF-loaded chitosan microspheres.

Role of the peritoneal cavity in the prevention of postoperative adhesions, pain, and fatigue

A surgical trauma results within minutes in exudation, platelets, and fibrin deposition. Within hours, the denuded area is covered by tissue repair cells/macrophages, starting a cascade of events. Epithelial repair starts on day 1 and is terminated by day 3. If repair is delayed by decreased fibrinolysis, local inflammation, or factors in peritoneal fluid, fibroblast growth starting on day 3 and angiogenesis starting on day 5 results in adhesion formation. For adhesion formation, quantitatively more important are factors released into the peritoneal fluid after retraction of the fragile mesothelial cells and acute inflammation of the entire peritoneal cavity. This is caused by mechanical trauma, hypoxia (e.g., CO₂ pneumoperitoneum), reactive oxygen species (ROS; e.g., open surgery), desiccation, or presence of blood, and this is more severe at higher temperatures. The inflammation at trauma sites is delayed by necrotic tissue, resorbable sutures, vascularization damage, and oxidative stress. Prevention of adhesion formation therefore consists of the prevention of acute inflammation in the peritoneal cavity by means of gentle tissue handling, the addition of more than 5% N₂O to the CO₂ pneumoperitoneum, cooling the abdomen to 30°C, prevention of desiccation, a short duration of surgery, and, at the end of surgery, meticulous hemostasis, thorough lavage, application of a barrier to injury sites, and administration of dexamethasone. With this combined therapy, nearly adhesion-free surgery can be performed today. Conditioning alone results in some 85% adhesion prevention, barriers alone in 40%-50%.