Pentoxifylline inhibits mature burn scar fibroblasts in culture

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Kick-Starting Wound Healing: A Review of Pro-Healing Drugs

Cutaneous wound healing consists of four stages: hemostasis, inflammation, proliferation/repair, and remodeling. While healthy wounds normally heal in four to six weeks, a variety of underlying medical conditions can impair the progression through the stages of wound healing, resulting in the development of chronic, non-healing wounds. Great progress has been made in developing wound dressings and improving surgical techniques, yet challenges remain in finding effective therapeutics that directly promote healing. This review examines the current understanding of the pro-healing effects of targeted pharmaceuticals, re-purposed drugs, natural products, and cell-based therapies on the various cell types present in normal and chronic wounds. Overall, despite several promising studies, there remains only one therapeutic approved by the United States Food and Drug Administration (FDA), Becaplermin, shown to significantly improve wound closure in the clinic. This highlights the need for new approaches aimed at understanding and targeting the underlying mechanisms impeding wound closure and moving the field from the management of chronic wounds towards resolving wounds.

Modulation of miR-145-5p and miR-146b-5p levels is linked to reduced parasite load in H9C2 Trypanosoma cruzi infected cardiomyoblasts

In the heart tissue of acutely Trypanosoma cruzi-infected mice miR-145-5p and miR-146b-5p are, respectively, downregulated and upregulated. Here, we used the H9C2 rat cardiomyoblast cell line infected with the Colombian T. cruzi strain to investigate the parasite-host cell interplay, focusing on the regulation of miR-145-5p and miR-146b-5p expression. Next, we explored the effects of interventions with the trypanosomicidal drug Benznidazole (Bz) alone or combined with Pentoxifylline (PTX), a methylxanthine derivative shown to modulate immunological and cardiac abnormalities in a model of chronic chagasic cardiomyopathy, on parasite load and expression of miR-145-5p and miR-146b-5p. The infection of H9C2 cells with trypomastigote forms allowed parasite cycle with intracellular forms multiplication and trypomastigote release. After 48 and 144 h of infection, upregulation of miR-145-5p (24 h: 2.38 ± 0.26; 48 h: 3.15 ± 0.9-fold change) and miR-146b-5b (24 h: 2.60 ± 0.46; 48 h: 2.97 ± 0.23-fold change) was detected. The peak of both miRNA levels paralleled with release of trypomastigote forms. Addition of 3 µM and 10 µM of Bz 48 h after infection reduced parasite load but did not interfere with miR-145-5p and miR-146b-5p levels. Addition of PTX did not interfere with Bz-induced parasite control efficacy. Conversely, combined Bz + PTX treatment decreased the levels of both microRNAs, resembling the expression levels detected in non-infected H9C2 cells. Moreover, the use of miR-145-5p and miR-146b-5p mimic/inhibitor systems before infection of H9C2 cells decreased parasite load, 72 h postinfection. When H9C2 cells were treated with miR-145-5p and miR-146b-5p mimic/inhibitor 48 h after infection, all the used systems, except the miR-146b-5p inhibitor, reduced parasite load. Altogether, our data indicate that these microRNAs putatively control signaling pathways crucial for parasite–host cell interaction. Thus, miR-145-5p and miR-146b-5p deserve to be further investigated as biomarkers of parasite control and tools to identify therapeutic adjuvants to etiological treatment in Chagas disease.

Intralesional pentoxifylline, triamcinolone acetonide, and their combination for treatment of keloid scars

BACKGROUND

Keloids are common fibroproliferative tumors, and their treatment still represents a dilemma. Intralesional triamcinolone acetonide (TAC) injection is effective, but frequently associated with side effects. Pentoxifyllin (PTX) is a vasodilator, anti-inflammatory, and antifibrotic agent. Its intralesional injection in keloids has not been evaluated yet.

AIMS

Evaluating the efficacy and safety of intralesional PTX versus intralesional TAC and their combination for treatment of keloids.

PATIENTS/METHODS

Thirty patients with keloids were divided into three equal groups and treated by intralesional injection of TAC, PTX, or their combination (admixed in 1:1 ratio). Injections were repeated every 3 weeks until lesional flattening or for maximum of 5 sessions. The evaluation was done using the Vancouver Scar Scale and the Verbal Rating Scale for pain and itching.

RESULTS

A significant improvement in VSS was detected in all groups. Significantly better improvements in keloid height, pliability, pain, and itching were detected in the TAC and combination groups than in the PTX group. There was a significantly higher incidence of side effects (atrophy, hypopigmentation, telangiectasia, and precipitation of TAC) in the TAC group than in the combination group, while no side effects were reported in the PTX group. A statistically significant reduction in the number of treatment sessions (required to achieve best results) was detected in patients in the combination group.

CONCLUSIONS

Intralesional injection of PTX is a potentially helpful, safe, and well-tolerated therapeutic tool for keloids, but with lower efficacy than intralesional TAC when used solely. Combining PTX and TAC produces significantly better results for keloid treatment and lowers the risk of TAC-induced side effects.

Nonsurgical Management of Hypertrophic Scars: Evidence-Based Therapies, Standard Practices, and Emerging Methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.

Investigating the skin penetration and wound healing properties of niosomal pentoxifylline cream

Wounds are defined as any injuries to the skin. Wounds can cause great inconvenience and health problems for the patients depending on the healing time and severity. This makes wound healing and the strategies to treat a wound or reduce their treatment time, an important concern in health care systems. Pentoxifylline (PTX) has been reported to facilitate the wound healing in systemic administration. Different cellular and immunological mechanisms have been reported and suggested regarding the promising effects of PTX. On the other hand, the topical application of PTX seems to improve its therapeutic efficiency by localizing the drug on the wound site. In this study, PTX-niosomes were prepared and characterized. Niosomes with Zavg of 150, 200, and 300 nm were incorporated into the base cold cream. In-vitro release of PTX from these formulations was obtained between 70 -100%. Ex-vivo penetration/retention studies showed that niosomal formulations (F₆ and F₇) increased penetration of PTX by 1.8 and 1.2 times, respectively in comparison with the PTX-conventional cream. Retention of PTX from both niosomal creams was about 2 times higher than the PTX-conventional cream. In -vivo studies on the full-thickness wound in BALB/c mice showed that PTX-niosomal creams shortened the duration of wound healing by two days compared to control groups (PTX-conventional cream, base cream, and no treatment). The final wound size in the niosomal cream-treated group was also significantly smaller than the control groups. Histological analysis of the wounds confirmed the results of in-vivo studies.

The Akt/FoxO/p27Kip1 axis contributes to the anti-proliferation of pentoxifylline in hypertrophic scars

Hypertrophic scars (HS) are characterized by the excessive production and deposition of extracellular matrix (ECM) proteins. Pentoxifylline (PTX), a xanthine derived antioxidant, inhibits the proliferation, inflammation and ECM accumulation of HS. In this study, we aimed to explore the effect of PTX on HS and further clarify the mechanism of PTX‐induced anti‐proliferation. We found that PTX could significantly attenuate proliferation of HS fibroblasts and fibrosis in an animal HS model. PTX inhibited the proliferation of HSFs in a dose‐ and time‐dependent manner, and this growth inhibition was mainly mediated by cell cycle arrest. Transcriptome sequencing showed that PTX affects HS formation through the PI3K/Akt/FoxO1 signalling pathway to activate p27^Kip1. PTX down‐regulated p‐Akt and up‐regulated p‐FoxO1 in TGF‐β1 stimulated fibroblasts at the protein level, and simultaneously, the expression of p27^Kip1 was activated. In a mouse model of HS, PTX treatment resulted in the ordering of collagen fibres. The results revealed that PTX regulates TGFβ1‐induced fibroblast activation and inhibits excessive scar formation. Therefore, PTX is a promising agent for the treatment of HS formation.

A Comparison of Gene Expression of Decorin and MMP13 in Hypertrophic Scars Treated With Calcium Channel Blocker, Steroid, and Interferon: A Human-Scar-Carrying Animal Model Study

BACKGROUND

The formation of hypertrophic scaring (HSc) is an abnormal wound-healing response. In a previous study, an animal model with human scar tissue implanted into nude mice (BALB/c) has been successfully established. The effects of verapamil as well as combination therapy with verapamil and kenacort have been studied and compared.

OBJECTIVE

To treat persistent hypertrophic scars, local injection of drugs composed of steroids, calcium channel blockers (CCBs), and interferon might be a good method. What is the best dose of the regimen and what are the mechanisms are also a worthwhile study.

MATERIALS AND METHODS

Scar specimens were harvested from patients with HSc or Keloid resulting from burn injury, and then implanted to BALB/c-nu nude mice for 4 weeks. Before implantation, the specimen was either injected with or without drugs such as steroids (kenacort), CCBs (verapamil), and interferons (INFα2b), respectively. After the removal of implants, quantitative gene expressions of decorin and collagenase (MMP13) were measured using a real-time polymerase chain reaction to detect their mRNAs. Two way-ANOVA and Post Hoc were used for statistical analysis using the software SPSS 15.0.

RESULTS

All drug-treated groups increased the expressions of decorin and MMP13 in comparison with those in noninjected group (p < .001) in a dose-dependent manner. Comparing equal amounts of individual drugs, gene expression of decorin was increased with increasing injection amount, and the best result in low amount of injection (0.02 mL of each) was shown in the group injected with INFα2b followed by kenacort and verapamil. However, the results were changed while injection amount was up to 0.04 mL and the strongest decorin gene expression was found in kenacort injection. Regarding MMP-13 expression, low-amount injection (0.02 mL) of INFα2b has strongest gene expression followed by kenacort and verapamil, but in the large-amount regimes (0.04 mL), verapamil had strongest gene expression followed by INFα2b and kenacort.

CONCLUSION

This study showed that the kenacort, verapamil, and INFα2b all inhibited HSc in a dose-dependent manner through the evidence of gene expression of decorin and MMP13. In comparison with the injections between small amounts of drugs, INFα2b potentiated the strongest decorin and MMP13 expression. On the contrary, among the large-amount injection regimes, kenacrot was more effective on decorin expression as verapamil to MMP13 expression. To decrease side effects from the drugs and produce promising results for the clinical practice, it is suggested to maintain the dose of INFα2b along with an increased dose of verapamil for HSc improvement.

Pentoxifylline and its applications in dermatology

Pentoxifylline is a methyl-xanthine derivative with many anti inflammatory effects. Pentoxifylline has been found to be effective for many dermatological as well as non-dermatological conditions. It has been used both as primary drug as well as adjuvant and is a safe and relatively cost-effective alternative drug. In this article, we review the literature and highlight various important aspects of pentoxifylline.

Up-to-date approach to manage keloids and hypertrophic scars: a useful guide

Keloids and hypertrophic scars occur anywhere from 30 to 90% of patients, and are characterized by pathologically excessive dermal fibrosis and aberrant wound healing. Both entities have different clinical and histochemical characteristics, and unfortunately still represent a great challenge for clinicians due to lack of efficacious treatments. Current advances in molecular biology and genetics reveal new preventive and therapeutical options which represent a hope to manage this highly prevalent, chronic and disabling problem, with long-term beneficial outcomes and improvement of quality of life. While we wait for these translational clinical products to be marketed, however, it is imperative to know the basics of the currently existing wide array of strategies to deal with excessive scars: from the classical corticotherapy, to the most recent botulinum toxin and lasers. The main aim of this review paper is to offer a useful up-to-date guideline to prevent and treat keloids and hypertrophic scars.

Cutaneous scarring: a clinical review

Cutaneous scarring can cause patients symptoms ranging from the psychological to physical pain. Although the process of normal scarring is well described the ultimate cause of pathological scarring remains unknown. Similarly, exactly how early gestation fetuses can heal scarlessly remains unsolved. These questions are crucial in the search for a preventative or curative antiscarring agent. Such a discovery would be of enormous medical and commercial importance, not least because it may have application in other tissues. In the clinical context the assessment of scars is becoming more sophisticated and new physical, medical and surgical therapies are being introduced. This review aims to summarise some of the recent developments in scarring research for non-specialists and specialists alike.

Pentoxifylline modifies three-dimensional collagen lattice model contraction and expression of collagen types I and III by human fibroblasts derived from post-burn hypertrophic scars and from normal skin

Fibroblasts are thought to be partially responsible for the persisting contractile forces that result in burn contractures. Using a monolayer cell culture and fibroblast populated collagen lattice (FPCL) three-dimensional model we subjected hypertrophic scar and non-cicatricial fibroblasts to the antifibrogenic agent pentoxifylline (PTF - 1mg/mL) in order to reduce proliferation, collagen types I and III synthesis and model contraction. Fibroblasts were isolated from post-burn hypertrophic scars (HSHF) and non-scarred skin (NHF). Cells were grown in monolayers or incorporated into FPCL's and exposed to PTF. In monolayer, cell number proliferation was reduced (46.35% in HSHF group and 37.73% in NHF group, p<0.0001). PTF selectively inhibited collagen III synthesis in the HSHF group while inhibition was more evident to type I collagen synthesis in the NHF group. PTF also reduced contraction in both (HSHF and NHF) FPCL.

Prevention and management of hypertrophic scars and keloids after burns in children. J Craniofac Surg. 2008;19:989-1006. [PMID: 18650721 DOI: 10.1097/scs.0b013e318175f3a7]

Hypertrophic scars and keloids are challenging to manage, particularly as sequelae of burns in children in whom the psychologic burden and skin characteristics differ substantially from adults. Prevention of hypertrophic scars and keloids after burns is currently the best strategy in their management to avoid permanent functional and aesthetical alterations. Several actions can be taken to prevent their occurrence, including parental and children education regarding handling sources of fire and flammable materials, among others. Combination of therapies is the mainstay of current burn scar management, including surgical reconstruction, pressure therapy, silicon gels and sheets, and temporary garments. Other adjuvant therapies such as topical imiquimod, tacrolimus, and retinoids, as well as intralesional corticosteroids, 5-fluorouracil, interferons, and bleomycin, have been used with relative success. Cryosurgery and lasers have also been reported as alternatives. Newer treatments aimed at molecular targets such as cytokines, growth factors, and gene therapy, currently in developing stages, are considered the future of the treatment of postburn hypertrophic scars and keloids in children.

Nonsurgical management of hypertrophic scars: evidence-based therapies, standard practices, and emerging methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.