Comparison of the Effect of Low-Level Laser and Phenytoin Therapy on Skin Wound Healing in Rats

Histomorphometric Analysis of the Healing Capacity of Low-Level Laser on Thermally Induced Tongue Ulcers for Gamma-Irradiated Rats

Objective: This study aimed to assess the efficacy of low-level laser therapy (LLLT) for treating thermal tongue ulcers in gamma-irradiated rats. Background: Postradiotherapeutic trauma may cause cell death, tissue damage, organ dysfunction, and loss of hematological components. Materials and methods: Thermal ulcers were induced on the dorsal surfaces of tongues of gamma-irradiated rats (15 Gy). Rats were divided into three groups, group 1 received no treatment, group 2 was subjected to a single dose of diode laser 807 nm with energy density 4 J/cm2, and group 3 was subjected to the same dose of LLLT but fractionated into three sessions at days 1, 3, and 5 after ulcers induction. Ulcers were assessed clinically for their areas and healing percentage. Specimens were examined for the quality of ulcer closure and expression of IL-1β and TGF-β1. Results: Results revealed significant improvement of ulcer healing clinically and histologically in both treatment groups compared to control. Moreover, IL-1β and TGF-β1 expression in both treatment groups was high at the earlier stage of healing then declined by time to reach a normal level. However, untreated group showed higher expression of IL-1β and TGF-β1 compared to treatment groups. In addition, IL-1β expression decreased by time but still of high level and TGF-β1 expression increased then declined. Conclusions: We concluded that gamma radiation-impaired mucosal healing could be related to the over expression of IL-1β and TGF-β1. LLLT, whether one session or fractionated, could be an effective treatment for postradiotherapeutic ulcers. The healing power of LLLT might be due to modulation of IL-1β and TGF-β1. Clinical Trial Registration number is 25A122.

Topical phenytoin administration accelerates the healing of acetic acid-induced colitis in rats: evaluation of transforming growth factor-beta, platelet-derived growth factor, and vascular endothelial growth factor

Ulcerative colitis (UC), limited to the colon's innermost lining, has become a global health problem. Immunomodulatory and monoclonal antibodies are used to treat UC despite their side effects and limitations. Phenytoin is used to heal wounds owing to its effects on growth factors, collagen, and extracellular matrix synthesis. This study aimed to evaluate the effect of topical phenytoin administration in UC. Phenytoin was administered in two doses during the treatment. Eighty male Wistar rats (230-280 g) were divided randomly into ten groups of sham, control, hydrocortisone, phenytoin 1%, and 3% groups in 6- or 12-day treatment protocols. The UC model was induced by the administration of acetic acid 4% into the colon. Animals were killed on the 7th and 13th postoperative days. The main outcome measures included body weight loss, microscopic score, and ulcer index measured using specific criteria. Growth factors were measured by western blotting. Results illustrated that body weight loss was reversed in the treatment groups. Ulcer index had decreased on 6- and 12-day treatment protocols. Microscopic scores in 6-day enema treatment significantly decreased compared to the control groups. Transforming growth factor-beta (TGFβ) significantly increased in a time-dependent manner and platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) significantly increased in a time- and dose-dependent manner in phenytoin 1% and 3% in the 6- and 12-day protocols. Phenytoin dose- and time-dependently reversed weight loss. In addition, histopathological parameters included microscopic scores, and the ulcer index was decreased through the induction of growth factors TGFβ, PDGF, and VEGF and consequently accelerated ulcer healing.

Light-emitting diode irradiation using 660 nm promotes human fibroblast HSP90 expression and changes cellular activity and morphology

We evaluated changes in cell viability and morphology in response to low-level light irradiation and underlying variations in the levels of heat shock proteins (HSPs). Human fibroblasts were irradiated with a light-emitting diode (LED) array at 660 nm (50 mW for 15, 30, and 60 minutes). Cell viability and morphological changes were evaluated via epifluorescence analysis; we also assessed cell viability and length changes. The expression levels of adenosine triphosphate (ATP) and various HSPs (HSP27, 60, 70, and 90) were analyzed by immunohistochemical staining, Western blotting and microarray analysis. After LED irradiation, cellular viability and morphology changed. Of the several HSPs analyzed, the HSP90 level increased significantly, suggesting that this protein played roles in the morphological and cellular changes. Thus, low-level irradiation triggered cellular changes mediated by increased HSP90 expression; this may explain why skin irradiation enhances wound-healing.

Comparative Evaluation of the Efficacy of Laser Therapy and Fibroblastic Growth Factor Injection on Mucosal Wound Healing in Rat Experimental Model

Introduction: The aim of the present study was to compare the effects of laser and basic fibroblastic growth factor (bFGF) treatment on operative wound healing in a rat model. Methods: Sixty-six male Wistar rats were employed in this study. A 10-mm surgical wound was created on the buccal mucosa of each rat, under anesthesia, and then the rats were divided into 3 groups of 22: (1) GF group (received subcutaneous injection of bFGF), (2) laser group (treated with low-level laser irradiation), and (3) control group (received no treatment). On day 5, half of the rats in each group and on day 10 the other half, were sacrificed. Afterward, samples were taken from rats' buccal mucosa for histological assay and scoring. The data were analyzed using MannWhitney test (α =5%). Results: On day 5 there was not any significant difference between GF and control groups; however, the laser group showed clinically delayed wound coverage, compared to other groups (P<0.05). On day 10, histological examination demonstrated marked vascular granulation tissue ( GT) in GF group. Collagen production was significantly prominent in laser group compared to GF treated samples (P=0.004). Inflammation of GT in GF and laser groups was significantly less than that in control samples (P=0.005 and P=0.001, respectively). Conclusion: The components of wound matrix induced by GF and laser treatment were significantly different. Although bFGF or laser treatment of oral wounds, under the conditions of the present study, did not accelerate wound healing, they showed some other notable effects on the quality of healing.

The Combined Effects of Levothyroxine and Low Level Laser Therapy on Wound Healing in Hypothyroidism Male Rat Model

Introduction: Hypothyroidism is caused by inadequate production and storage of thyroid hormones. Hypothyroidism is associated with delayed wound healing. Laser therapy may stimulate wound regeneration. The aim of this study was to determine the combined effects of levothyroxine and low level laser therapy during the wound healing process on skin of hypothyroidism male rat model. Methods: Thirty male Wistar rats were randomly divided into 5 groups: control group, hypothyroidism group, hypothyroidism group treated by laser, hypothyroidism group treated by levothyroxine, and hypothyroidism group treated by laser and levothyroxine. To induce hypothyroidism, methimazole was given at a dose of 4 mg/100 mL in their drinking water. After hypothyroidism was proven through immunoassay commercial kit, rats were generally anesthetized with ketamine and xylazine, then, an incisional skin wound was created in a length of 1.2 cm on the back of the ribcage. The surgical day is considered as the zero day. The third and fifth groups were treated with a pulse laser, 810 nm wavelength 80 Hz frequency and 0.2 J/cm² energy densities for 200 seconds. Levothyroxine was injected to the fourth and fifth groups intraperitoneally. On the 14th day, a normal sample of each healing skin wound was harvested for biomechanical examination. The obtained data were analyzed by the SPSS software 21 and reported as a mean ± standard error of mean (SEM). P < 0.05 was considered statistically significant. Results: The results showed that the mean maximum force and the accomplished work (energy) made a significant difference in the group receiving both laser and levothyroxine synchronously rather than the other groups (P ≤ 0.05). The elasticity of the wound healing in the groups that received laser and levothyroxine synchronously was significantly higher in comparison with the control and hypothyroidism groups but the difference was not significant in comparison with the laser or levothyroxine groups. Conclusion: The results of our study showed that the application of laser and levothyroxine synchronously improves the biomechanical parameters of wound during healing in comparison to the use of laser and levothyroxine solely.

Stimulation Effect of Low Level Laser Therapy on Sciatic Nerve Regeneration in Rat

Introduction: Recent studies showed that low-level laser therapy (LLLT) accelerates the regeneration process of injured peripheral nerve tissue. The objective of this study was investigate the effect of LLLT (780 nm) on regeneration of injured right sciatic nerve of male Wistar rat. Methods: In this research work, the effect of LLLT (780 nm) on the regeneration process and reconstruction of injured peripheral right side sciatic nerve was investigated. Twelve adult male Wistar rats underwent surgery in aseptic conditions under general anesthesia to induce a lesion to their right side sciatic nerve according to standard protocol. Before suturing the location, only the experimental group was treated by laser. The damaged nerve was directly irradiated with (2 J, 100 mW, 40 seconds). The irradiation procedure was terminated in 21 days with little improvement (4 J, 200 mW, 40 seconds) across the skin surface of experimental group. Rats were selected randomly from each group to be sacrificed on different periods and histopathological examination was carried out on the extracted nerves. Results: Significant acceleration of revascularization and angiogenesis of the injury site was observed in the experimental group. Furthermore, a reduction of hemorrhages and increase in blood supply was observed. Also, Wallerian degeneration decreased while higher axonal density compared to the control rats was observed. Moreover, the cross-section analysis of the injured area on the 14th and 21st days as post-surgery showed that the nerve sheath diameter in the lesion area of the experimental group was reduced. While the ratio between thicknesses increased in the control group. Conclusion: The results of the current study suggest that laser phototherapy at 780 nm exactly could accelerate the regeneration process of injured peripheral nerves tissue.

Topical phenytoin for treating pressure ulcers

BACKGROUND

Pressure ulcers are common in clinical practice and pose a significant health problem worldwide. Apart from causing suffering to patients, they also result in longer hospital stays and increase the cost of health care. A variety of methods are used for treating pressure ulcers, including pressure relief, patient repositioning, biophysical strategies, nutritional supplementation, debridement, topical negative pressure, and local treatments including dressings, ointments and creams such as bacitracin, silver sulphadiazine, neomycin, and phenytoin. Phenytoin is a drug more commonly used in the treatment of epilepsy, but may play an important role in accelerating ulcer healing.

OBJECTIVES

To assess the effects of topical phenytoin on the rate of healing of pressure ulcers of any grade, in any care setting.

SEARCH METHODS

In September 2016, we searched the following electronic databases to identify relevant randomized clinical trials: the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library); Ovid MEDLINE; Ovid Embase; and EBSCO CINAHL Plus. We handsearched conference proceedings from the European Pressure Ulcer Advisory Panel, European Wound Management Association and the Tissue Viability Society for all available years. We searched the references of the retrieved trials to identify further relevant trials. We also searched clinical trials registries to identify ongoing and unpublished studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) addressing the effects (both benefits and harms) of topical phenytoin on the healing of pressure ulcers of any grade compared with placebo or alternative treatments or no therapy, irrespective of blinding, language, and publication status.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted information on participants, interventions, methods and results and assessed risk of bias using Cochrane methodological procedures. For dichotomous variables, we calculated the risk ratio (RR) with 95% confidence interval (CI). For continuous variables, we calculated the mean difference with 95% CI. We rated the quality of the evidence by using Grading of Recommendations, Assessment, Development and Evaluation approach (GRADE).

MAIN RESULTS

Three small RCTs met our inclusion criteria and included a total of 148 participants. These compared three treatments with topical phenytoin: hydrocolloid dressings, triple antibiotic ointment and simple dressings. In the three RCTs, 79% of participants had grade II ulcers, and 21% of participants had grade I ulcers; no participants had grade III or IV ulcers. Two RCTs had a high risk of bias overall and the other RCT was at unclear risk of bias due to poor reporting. Two RCTs had three intervention arms and the other had two intervention arms.Two studies compared topical phenytoin with hydrocolloid dressing (84 participants analysed). The available data suggest that hydrocolloid dressings may improve ulcer healing compared to topical phenytoin (39.3% ulcers healed for phenytoin versus 71.4% ulcers healed for hydrocolloid dressings (RR 0.55, 95% CI 0.33 to 0.92; 56 participants, 1 study; low quality evidence). We downgraded the evidence twice: once due to serious limitations (high risk of bias) and once due to the small sample size and small number of events. Two studies compared topical phenytoin with simple dressings (81 participants analysed). From the available data, we are uncertain whether topical phenytoin improves ulcer healing compared to simple dressings (39.3% ulcers healed for phenytoin versus 29.6% ulcers healed for the simple dressing (RR 1.33, 95% CI 0.63 to 2.78; 55 participants, 1 study; very low quality evidence). This evidence was downgraded once due to serious limitations (high risk of bias) and twice due to the low number of outcome events and resulting wide CI which included the possibility of both increased healing and reduced healing. We therefore considered it to be insufficient to determine the effect of topical phenytoin on ulcer healing. One study compared topical phenytoin with triple antibiotic ointment, however, none of the outcomes of interest to this review were reported. No adverse drug reactions or interactions were detected in any of the three RCTs. Minimal pain was reported in all groups in one trial that compared topical phenytoin with hydrocolloid dressings and triple antibiotic ointment.

AUTHORS' CONCLUSIONS

This review has considered the available evidence and the result shows that it is uncertain whether topical phenytoin improves ulcer healing for patients with grade I and II pressure ulcers. No adverse events were reported from three small trials and minimal pain was reported in one trial. Therefore, further rigorous, adequately powered RCTs examining the effects of topical phenytoin for treating pressure ulcers, and to report on adverse events, quality of life and costs are necessary.