Diphenylhydantoin sodium promotes early and marked angiogenes is and results in increased collagen deposition and tensile strength in healing wounds

Outcomes of topical phenytoin in the management of traumatic wounds

INTRODUCTION

Regular dressing of traumatic wounds is of paramount importance for healing. Phenytoin, an anticonvulsant, is thought to promote wound healing through multiple mechanisms, including fibroblast proliferation, granulation tissue formation, antibacterial activity, and pain alleviation.

AIM

To assess the effect of topical phenytoin on traumatic wound healing in terms of granulation tissue formation, pain alleviation, and time taken for wound healing.

METHODOLOGY

Fifty patients with traumatic wounds were divided into equal and comparable groups. After cleaning the wound, phenytoin dressing was done in the study group and saline dressing in the control group. Thereafter, regular dressings of the wounds were done, and healing was assessed on day 14 and day 21.

RESULTS

On day 14, the wound surface area, percentage of granulation tissue, VAS score amongst cases was 39.4 ± 29.75 cm², 82.12 ± 9.71%, 4.52 ± 1.08, and that of controls was and 51.28 ± 25.33 cm², 62.72 ± 9.01%, 6.52 ± 1.22, respectively. On day 21, the wound surface area, percentage of granulation tissue, VAS score amongst cases were 29.4 ± 29.88 cm², 92 ± 4.46%, 2.8 ± 0.94, and that of controls were 38.92 ± 23.24 cm², 78.56 ± 8.19%, and 4.88 ± 1.17, respectively. The time taken for wound healing was 21.76 ± 5.28 days amongst cases and 31.64 ± 8.31 days amongst controls. Staphylococcus aureus was the commonest organism isolated in both the groups. On day 14,18(72%), wounds in the study group showed negative culture, whereas, in the control group, it was negative in 12 (48%) patients. The rate of granulation tissue formation was higher in cases when compared to controls amongst smokers and diabetics. The difference in all these parameters between the groups was statistically significant (P-value <0.05).

DISCUSSION AND CONCLUSION

We observed a considerable increase in granulation tissue formation, pain alleviation, and reduction in time taken for wound healing. Topical phenytoin is a safe, effective, readily available, and frugal agent that can accelerate wound healing through its multimodal action, thus reducing patient morbidity and economic burden.

MESH TERMS

Phenytoin, Wound healing, Topical, Ulcer, Anticonvulsant, Granulation Tissue, Saline dressing.

Role of Phenytoin in Diabetic Foot Ulcers

Of the complications of diabetes mellitus, foot ulcers are the most dreaded complications, as they can progress at an alarming rate and can be very difficult to treat. Various modalities have been described in the treatment of diabetic foot ulcers. One such modality of phenytoin therapy uses the disadvantage of the drug, that is, gingival hyperplasia to the advantage of wound healing. We hereby report a case of diabetic foot ulcer managed with injection phenytoin sprayed topically over the wound.

Comparison of honey and phenytoin (PHT) cream effects on intensity of pain and episiotomy wound healing in nulliparous women

Background This study investigates and compares the effect of phenytoin and honey cream on intensity of pain and episiotomy wound healing in nulliparous women. Methods This research was conducted by double-blinded randomized clinical trial method on 120 nulliparous women in three groups of phenytoin, honey and placebo. After delivery and episiotomy, mothers used a knuckle of the prescribed creams on their episiotomy area, every night until 10-night. Evaluation of wound healing using REEDA scale and pain intensity with numerical rating scale of pain took place within the first 24 h and after 7 and 14 days of delivery. Results Results showed significant differences between healing scores of the three groups for the seventh day after delivery. Healing score in the honey group was lower than that in placebo group. On the fourteenth day after delivery, the healing scores showed no significant differences between the three groups. Measuring pain intensity did not show any significant difference in the three groups after 7 and 14 days of delivery. Conclusions Both honey and phenytoin led to episiotomy wound healing; however, honey caused the wound healing better than the phenytoin. Honey and phenytoin did not reduce episiotomy pain.

Multiple functions of gingival and mucoperiosteal fibroblasts in oral wound healing and repair

Fibroblasts are cells of mesenchymal origin. They are responsible for the production of most extracellular matrix in connective tissues and are essential for wound healing and repair. In recent years, it has become clear that fibroblasts from different tissues have various distinct traits. Moreover, wounds in the oral cavity heal under very special environmental conditions compared with skin wounds. Here, we reviewed the current literature on the various interconnected functions of gingival and mucoperiosteal fibroblasts during the repair of oral wounds. The MEDLINE database was searched with the following terms: (gingival OR mucoperiosteal) AND fibroblast AND (wound healing OR repair). The data gathered were used to compare oral fibroblasts with fibroblasts from other tissues in terms of their regulation and function during wound healing. Specifically, we sought answers to the following questions: (i) what is the role of oral fibroblasts in the inflammatory response in acute wounds; (ii) how do growth factors control the function of oral fibroblasts during wound healing; (iii) how do oral fibroblasts produce, remodel and interact with extracellular matrix in healing wounds; (iv) how do oral fibroblasts respond to mechanical stress; and (v) how does aging affect the fetal-like responses and functions of oral fibroblasts? The current state of research indicates that oral fibroblasts possess unique characteristics and tightly controlled specific functions in wound healing and repair. This information is essential for developing new strategies to control the intraoral wound-healing processes of the individual patient.

The impact of topical phenytoin on recalcitrant neuropathic diabetic foot ulceration

OBJECTIVE

To study the impact of topical phenytoin on the healing of recalcitrant neuropathic diabetic foot ulcers in patients with no clinical evidence of ischaemia or infection, and to evaluate its antibacterial effect.

METHOD

Thirty-two patients were enrolled into the study. Topical phenytoin in the form of 2% aerosol powder was applied once daily in addition to the patient's usual treatment (weekly sharp debridement, offloading and use of a gauze dressing) for eight weeks. The primary outcome was change in ulcer area over time, measured by grid tracing. Secondary outcomes were the ability of topical phenytoin to eradicate bacterial isolates, and the occurrence of adverse events.

RESULTS

Topical phenytoin significantly improved healing of recalcitrant neuropathic diabetic foot ulcers. Baseline wound area was 319.3 + 340.4 mm2, reducing to 286.1 + 341.1 mm2 and 269.1 + 341.2 mm2 after four and eight weeks respectively. However, the overall reduction in ulcer size was only 18.3% + 27.5% and 25.7% + 38.6 % respectively. Topical phenytoin therapy over eight weeks did not eradicate any of the bacterial wound isolates (Staphylococcus spp., Proteus spp. or Pseudomonas spp.). Of the 32 patients evaluated, only eight (25%) achieved more than 50% reduction in ulcer size after eight weeks of treatment.

CONCLUSION

Topical phenytoin can enhance wound healing in recalcitrant neuropathic diabetic foot ulcers, although only one-quarter of patients achieved more than 50% reduction in ulcer size after eight weeks of therapy. Further research is needed to characterise those patients who will satisfactorily respond to such therapy.

Prolonged use of high-dose morphine impairs angiogenesis and mobilization of endothelial progenitor cells in mice

BACKGROUND

Morphine is one of the most commonly prescribed analgesics for treating wound pain. Using a mouse model of excisional wound injury, we determined the effects of high-dose morphine on angiogenesis and mobilization of endothelial progenitor cells.

METHODS

An excisional wound was created on mice treated with placebo or morphine (20 mg/kg, i.p. injection for 14 days). Wound healing was compared by measuring the final-to-initial wound area ratio. Generation of superoxide anions in the wound was determined by luminol-enhanced chemiluminescence. Circulating mononuclear cells were isolated and measured for endothelial progenitor cell (defined as CD34+/CD133+ cell) counts. In vivo and in vitro measurements of angiogenesis after morphine treatment were performed using the Matrigel assay.

RESULTS

Mice treated with morphine had reduced wound closure and higher wound superoxide ions concentrations than control mice. Morphine reduced the number of postwound circulating endothelial progenitor cells. Matrigel assay showed impaired angiogenesis in animals and reduced capillary tube formation in cultured endothelial cells treated with morphine.

CONCLUSION

High-dose morphine impaired angiogenesis, increased systemic oxidative stress, and impaired mobilization of endothelial progenitor cells. This study emphasizes the potential detrimental effect of high-dose morphine on angiogenesis after systemic administration.

Topical diphenylhydantoin sodium can improve healing in a diabetic incisional animal wound model

OBJECTIVE

Anecdotally, topical application of diphenylhydantoin sodium (DpH) (phenytoin) has been shown to aid wound healing. We previously reported improved healing following topical infiltration of DpH in a healthy animal wound model. This study evaluates its effect on an incisional wound model in diabetic animals.

METHOD

Twenty-five male Sprague-Dawley rats were rendered diabetic by a single intraperitoneal injection of streptozotocin. Two caudal and two cephalad wounds were made on the dorsal surface. A polyvinyl alcohol sponge was placed in a subcutaneous pocket created proximal to both cephalad wounds. Each wound was either treated topically with 10mg DpH in a 200microl carrier or an equal volume of the saline vehicle (control) on the day of wounding and days 3 and 6 post-incision. The animals were sacrificed on day 10. The breaking strength of fresh and fixed wounds was determined by tensiometry, and the hydroxyproline content was determined spectrophotometrically.

RESULTS

There was a significant overall increase in both fresh (24%) and fixed (18%) wound-breaking strength of the DpH-treated wounds when compared with the controls (p<0.05). This was associated with an increase in collagen synthesis as indicated by the increased hydroxyproline content in the DpH-infiltrated sponges when compared with the controls.

CONCLUSION

Our data suggest that topical DpH improves healing in a diabetic wound model. Topical administration of DpH has the potential to accelerate diabetic wound healing and should be evaluated in human diabetic wounds.

Impact of phenytoin therapy on the skin and skin disease

Phenytoin (diphenylhydantoin; Dilantin), ALZA Corp.) is a highly effective and widely prescribed anticonvulsant agent used in the treatment of focal and tonic clonic generalised seizures. The side effects of phenytoin can occassionally engender significant morbidity. Phenytoin can induce generalised eruptions that include: a maculopapular exanthem, Stevens-Johnson syndrome, generalised exfoliative dermatitis, toxic epidermal necrolysis, vasculitis and fixed drug eruptions. Phenytoin is linked to a hypersensitivity syndrome that manifests with fever, rash and lymphadenopathy. Patients receiving phenytoin may develop pseudolymphoma or, rarely, malignant lymphoma and mycosis fungoides-like lesions. Rarer cutaneous side effects include drug-induced lupus, purple hand syndrome, pigmentary alterations and IgA bullous dermatosis. Phenytoin can effect clotting function and alter vitamin and mineral levels. Prenatal exposure to phenytoin may result in a spectrum of structural, developmental and behavioural changes, known as the fetal hydantoin syndrome. Patients who use phenytoin in the long-term commonly manifest with gingival hyperplasia, coarsening of the facies, and hirsutism.

Phenytoin-induced lymphocytic chemotaxis, angiogenesis and accelerated healing of decubitus ulcer in a patient with stroke

We studied the effect of topically applied phenytoin on the healing of a decubitus ulcer in the sacral region of an immobile patient with stroke. Another similar, but smaller, ulcer was treated with conventional treatment only and served as a control. The ulcers were measured once a week and biopsies were taken from the margins before, 1 week and 2 weeks after commencing treatment with phenytoin. Clinically, phenytoin substantially accelerated the rate of healing. Microscopic examination of the biopsies showed increased lymphocytic infiltration of the phenytoin-treated lesion. Anti-CD31 immunohistochemistry revealed dense CD31+ lymphocytic infiltration and increased angiogenesis only in the phenytoin-treated lesion. Our findings suggest that phenytoin enhances wound healing by stimulating lymphocytic chemotaxis and up-regulation of angiogenesis.

Role of phenytoin in wound healing: microarray analysis of early transcriptional responses in human dermal fibroblasts

Wound healing is a complex process involving a number of related genes and receptors. Using cDNA microarrays, we explored the global gene expression profile of phenytoin (20microg/ml) induced changes to human dermal fibroblasts. Microarray data analysis revealed approximately 1500 genes were differentially expressed by 2.5-fold. At 3, 6, 12, and 24h, the transcripts of the major growth factors involved in wound healing and their receptors were increased. This was further confirmed by RT-PCR. Genes encoding other proteins with roles in signal transduction (NFkappaB), extracellular matrix (MMP1) including type I collagen, fibronectin, and laminin were strongly induced at 6h and onwards. Genes involved in cell cycle regulation (CCND1 and CDKN1A) were down-regulated consistent with our finding that phenytoin per se did not have cell proliferation activity. Notably, phenytoin accelerates the autocrine and paracrine activity of growth factors by up-regulating the related receptors.

Effect of Sodium Diphenylhydantoin on Skin Wound Healing in Rats

This study evaluated the effect of phenytoin (sodium diphenylhydantoin) on skin wound healing in a rat model. The study was divided into two parts. In part I, 20 mul of phenytoin (10 mg/ml) was subcutaneously injected into the 3-cm dorsal full-thickness incisional wounds of 14 rats on postoperative days 0, 3, and 6. Twelve rats that received saline injections were used as the controls. The skin samples were harvested and tested for tensile strength and histology. An additional 12 rats with the same incisional wounds were tested for chemokine gene expressions. In part II, 20 mul of phenytoin (10 mg/ml) was applied topically once a day on a 4 x 4 cm area of the open dorsal wounds of 10 rats. Saline was applied to the wounds of the 10 control group rats. The wounds were measured weekly. The results showed that the average tensile strength of the phenytoin-treated wound was 0.49 +/- 0.08 MPa compared with the control group at 0.02 +/- 0.01 MPa (p < 0.05). The density ratio of chemokine monocyte chemotactic protein (MCP-1) to beta-actin in the phenytoin-treated group was also significantly higher than in the control group (p < 0.05). Histologic analysis of the phenytoin group showed a large amount of fibroblast proliferation, collagen synthesis, and neovascularization. Phenytoin-treated wounds were also smaller at 1 to 6 weeks postoperatively than the control group wounds. The authors conclude that the administration of phenytoin can promote wound healing and significantly increase MCP-1 expression. Phenytoin-treated wounds showed significant increase in collagen deposition and neovascularization, which resulted in an increased wound tensile strength and accelerated healing of both open and closed wounds.

Growth inhibition of prostate cancer xenografts by halofuginone

BACKGROUND

Halofuginone, an inhibitor of collagen type I synthesis, is an anti-angiogenic agent. Here we evaluated the efficacy of halofuginone to inhibit prostate cancer (PC) xenografts representing various phenotypes of the disease.

METHODS

An androgen-dependent (CWR22), an androgen-independent (PC3), and a neuroendocrine (WISH-PC2) PC xenograft were used. Halofuginone was given orally or injected intraperitoneally. Tumor size, collagen alpha1(I) gene expression (in situ hybridization), collagen content (sirius red staining), angiogenesis (immunohistochemistry with factor VIII antibodies), and apoptosis/necrosis (DNA fragmentation) were evaluated.

RESULTS

Halofuginone inhibited the growth of all subcutaneously implanted xenografts and of WISH-PC2 when transplanted orthotopically. The effect was dose-dependent (WISH-PC2) and accompanied by decrease in plasma PSA levels (CWR22). In all xenografts, halofuginone inhibited collagen alpha1(I) gene expression, reduced collagen content, and endothelial cell number resulting in an increase in apoptosis/necrosis.

CONCLUSIONS

Oral administration of halofuginone slowed the progression of PC xenografts representing a broad range of phenotypes. Halofuginone may become a new modality for PC prevention.

Evidence for the involvement of bone morphogenetic protein-2 in phenytoin-stimulated osteocalcin secretion in human bone cells

Recent work has shown that the actions of phenytoin on bone cell proliferation and differentiation are, in part, mediated through the upregulation of transforming growth factor-beta1 (TGF-beta(1)). The present study was undertaken to examine the effect of phenytoin on bone morphogenetic proteins (BMP)-2 and -4, which are well-recognized osteoinductive proteins of the TGF-beta superfamily, in osteoblastic cells. Treatment with 5-50 microM of phenytoin increased the amount of mRNA for BMP-2 after a 0.5-24 h incubation in normal human mandible-derived bone cells (HOB-M cells), but failed to affect the mRNA for BMP-4. Phenytoin treatment for 48 h significantly increased the secretion of BMP-2 by approx. four-fold, at an optimal concentration of 10 microM. While TGF-beta(1) inhibited osteocalcin secretion from HOB-M cells, both phenytoin and BMP-2 significantly stimulated it. Importantly, the stimulatory effects of phenytoin on osteocalcin release were completely blocked by the neutralizing antihuman BMP-2 monoclonal antibody. These results indicate that the stimulatory action of phenytoin on osteocalcin secretion in normal human bone cells is mediated, at least partly, through the upregulation of BMP-2, rather than that of TGF-beta(1).

Inhibition of neovascularization and tumor growth, and facilitation of wound repair, by halofuginone, an inhibitor of collagen type I synthesis

Halofuginone, an inhibitor of collagen alpha1(I) gene expression was used for the treatment of subcutaneously implanted C6 glioma tumors. Halofuginone had no effect on the growth of C6 glioma spheroids in vitro, and these spheroids showed no collagen alpha1(I) expression and no collagen synthesis. However, a significant attenuation of tumor growth was observed in vivo, for spheroids implanted in CD-1 nude mice which were treated by oral or intraperitoneal (4 microg every 48 hours) administration of halofuginone. In these mice, treatment was associated with a dose-dependent reduction in collagen alpha1(I) expression and dose- and time-dependent inhibition of angiogenesis, as measured by MRI. Moreover, halofuginone treatment was associated with improved re-epithelialization of the chronic wounds that are associated with this experimental model. Oral administration of halofuginone was effective also in intervention in tumor growth, and here, too, the treatment was associated with reduced angiogenic activity and vessel regression. These results demonstrate the important role of collagen type I in tumor angiogenesis and tumor growth and implicate its role in chronic wounds. Inhibition of the expression of collagen type I provides an attractive new target for cancer therapy.

Impaired wound healing and angiogenesis in eNOS-deficient mice

A role for nitric oxide (NO) in wound healing has been proposed; however, the absolute requirement of NO for wound healing in vivo and the contribution of endothelial NO synthase (eNOS) have not been determined. Experiments were carried out using eNOS gene knockout (KO) mice to determine the requirement for eNOS on wound closure and wound strength. Excisional wound closure was significantly delayed in the eNOS KO mice (29.4 +/- 2.2 days) compared with wild-type (WT) controls (20.2 +/- 0.4 days). At 10 days, incisional wound tensile strength demonstrated a 38% reduction in the eNOS KO mice. Because effective wound repair requires growth factor-stimulated angiogenesis, in vitro and in vivo angiogenesis assays were performed in the mice to assess the effects of eNOS deficiency on angiogenesis. Endothelial cell sprouting assays confirmed in vitro that eNOS is required for proper endothelial cell migration, proliferation, and differentiation. Aortic segments harvested from eNOS KO mice cultured with Matrigel demonstrated a significant reduction in endothelial cell sprouting and [(3)H]thymidine incorporation compared with WT mice at 5 days. Capillary ingrowth into subcutaneously implanted Matrigel plugs was significantly reduced in eNOS KO mice (2.67 +/- 0.33 vessels/plug) compared with WT mice (10.17 +/- 0.79 vessels/plug). These results clearly show that eNOS plays a significant role in facilitating wound repair and growth factor-stimulated angiogenesis.