Incorporation of 15-hydroxyeicosatrienoic acid in specific phospholipids of cultured human keratinocytes and psoriatic plaques

Abstract 15-hydroxyeicosatrienoic acid, 15-HETrE, the 15-lipoxygenase product of dihomogammalinolenic acid (DGLA), can inhibit the biosynthesis of the proinflammatory eicosanoids leukotriene B₄ (LTB₄) and 12-hydroxyeicosatctraenoic acid (12-HETE). The purpose of the present study was to investigate the incorporation of [^I4C] 15-HETrE in specific membrane phospholipids of cultured human keratinocytes in vitro. [^I4C] 15-HETrE was rapidly incorporated into keratinocytes. When a plateau was reached after 3 hours, 15% of the added radioactivity was incorporated into lipids; 96.5% into phospholipids (PL) and 3.5%. into neutral lipids (NL). Within the phospholipid classes, [^I4C]15-HETrE showed selectivity for incorporation into phosphatidylinositol (PI). The mean proportion of [^I4C] 15-HETrE in the PI, phosphatidylcholin (PC) and phosphatidyle-thanolamin (PE) was 83.2%, 8.5% and 8.3%, respectively. We then investigated the incorporation of 15-HETrE in epidermal phospholipids of psoriatic skin intralesionally injected with 15-HETrE. Four patients took part in the study. In each patient four identical plaques were injected with 0.65 ml of 2.0 µM, 6.2 µM, 18.6 µM of 15-HETrE (0.4 µg, 1, 2 µg and 3.6 µg respectively) or 0.65 ml of 0.88% NaCl twice a week. After 3 wk keratome biopsies were obtained from the treated plaques. Phospholipids extracted from the skin biopsies were separated into major classes by two-dimensional thin layer chromatography. 15-HETrE was then released from specific phospholipids after treatment with phospholipase A₂ and identified by reverse phase and straight phase high preformance liquid chromatography. There was a dose-dependent incorporation of 15-HETrE into the specific phospholipids PI and PC. When expressed as ng 15-HETrE/ug phospholipid phosphate, 15-HETrE accumulated preferent-ically in PI. After injection of the highest 15-HETrE concentration, the mean amount of 15-HETrE estcrified in PI and PC was 81.9 ng/µg PI phosphate and 19.4 ng/µg PC phosphate, respectively. This incorporation of 15-HETrE incorporated into epidermal PLs was not accompanied by a clinical change of the treated psoriatic plaques. It remains to be determined whether higher 15-HETrE incorporated might induce clinical improvement of psoriasis.     

The invasion of burned skin by Pseudomonas aeruginosa

When standard skin burns of mice were infected with a virulent strain of Pseudomonas aeruginosa there was rapid and extensive penetration of the burn and underlying tissues by the organisms. Under similar experimental conditions an a virulent strain of Ps. aeruginosa remained localized at the surface of the burned skin. In vitro experiments showed that heating did not make the proteins of skin more susceptible to hydrolysis by enzymes, since heated and unheated skin were hydrolysed to approximately the same extent by proteinases from both virulent and avirulent strains of Ps. aeruginosa.     

Effect of combination of photobiomodulation 904 nm superpulsed laser therapy and Hippophae rhamnoides L. on third-degree burn wound healing

Background

Burn is a traumatic injury and aesthetic scarless repair poses a great challenge in area of cosmetic dermatology. Focus on multimode therapeutic strategies to promote healing of burns by regulating various stages of healing is warranted. Photobiomodulation therapy (PBMT), a non-invasive modality grabs the attention to repair impaired wounds. Seabuckthorn extract (SBTL-ALE) is known to possess antioxidant, anti-inflammation, and tissue-repair abilities. Current study aims to assess the effect of combination treatment of PBM 904 nm superpulsed laser and SBTL-ALE (2.5%) on repair of third-degree burn in rats.

Methods

Rats were randomized into five groups: uninjured, control, SBTL-ALE, 904 nm PBMT, and combination. A transdermal burn wound was induced on the dorsal side of rats of all groups except the uninjured group and respective treatment was applied for 7 days postwounding.

Results

Dual treatment increased wound area contraction compared to control and either treatment alone. Immunohistochemical analyses exhibited increased angiogenesis, dermal hydration, collagen synthesis, and maintained redox homeostasis as evidenced by enhanced expression (p < 0.05) of CD31, aquaporin3, collagen type 3, Nrf2, and HO1 in combination group compared with control. Conversely, pro-inflammatory and oxidative stress markers exhibited reduced (p < 0.05) TNF-α, IL-6, IL-1β, NOS-2, ROS levels, and increased catalase activity in combined treatment. Furthermore, energy metabolizing enzymes viz. citrate synthase, CCO, and ATP contents were substantially (p < 0.05) increased, and LDH activity was reduced in the combination group.

Conclusions

Dual treatment (PBMT + SBTL-ALE) prominently accelerates third-degree burn wound healing in rats, which could pave the path for multimode therapeutic strategies for the management of burns and dermal cosmetic care.     

Effect of barrier perturbation on cutaneous penetration of salicylic acid in hairless rats: in vivo pharmacokinetics using microdialysis and non-invasive quantification of barrier function

Abstract The penetration of topically applied drugs is altered in diseased or barrier-damaged skin. We used microdialysis in the dermis to measure salicylic acid (SA) penetration in hairless rats following application to normal (unmodified) skin (n = 11) or skin with perturbed barrier function from (1) tape-stripping (n = 5), (2) sodium lauryl sulphate (SLS) 2% for 24 h (n = 3) or (3) delipidization by acetone (n = 4). Prior to the experiment, transepidermal water loss (TEWL) and erythema were measured. Two microdialysis probes were inserted into the dermis on the side of the trunk and 5% SA in ethanol was applied in a chamber overlying the probes. Microdialysis sampling was continued for 4 h, followed by measurements of probe depth by ultrasound scanning. SA was detectable in all samples and rapidly increasing up to 130 min. Microdialysates collected between 80 and 200 min showed mean SA concentrations of 3 μg/ml in unmodified and acetone-treated skin, whereas mean SA concentrations were 280 μg/ml in SLS-pretreated skin and 530 μg/ml in tape-stripped skin (P < 0.001). The penetration of SA correlated with barrier perturbation measured by TEWL (P < 0.001) and erythema (P < 0.001). A correlation between dermal probe depth and SA concentration was found in unmodified skin (P = 0.04). Microdialysis sampling in anatomical regions remote from the dosed site excluded the possibility that SA levels measured were due to systemic absorption. Microdialysis sampling of cutaneous penetration was highly reproducible. Impaired barrier function, caused by irritant dermatitis or tape stripping, resulted in an 80- to 170-fold increase in the drug level in the dermis. This dramatic increase in drug penetration could be relevant to humans, in particular to topical treatment of skin diseases and to occupational toxicology. Received: 15 October 1998 / Received after Revision: 5 March 1999 / Accepted: 12 March 1999     

Effect of incoherent LED radiation on third-degree burning wounds in rats

Abstract

The main physiological characteristics in a burn process are the increase of the capillary permeability and the occurrence of edema and exudation. Light-emitting diode (LED) has been proposed as treatment of burning. This study investigated the effects of LED on the repair process of rat skin submitted to a third-degree burning. The lesions were produced on the dorsal surface of male Wistar rats. Animals were divided into 4 groups (n = 6) as follows: L1 and L2 groups as LED-treated burned rats, and received LED therapy along 7 and 15 days with 48 hours intervals, respectively; C1 and C2 groups as control, non-treated burned rats. A red LED (640 nm, 30 mW) operating with a fluence of 4 J/cm² was used. The wound area was measured daily after irradiation. Animals were euthanized at the 8th and 16th days after burning, and the wound fragment was submitted to histology. The inflammatory cells as well as the damaged area at the 8th day after burns were significantly lower for the LED-treated group when compared to control. Furthermore, the LED phototherapy effect on cellular migration was even more pronounced at the 16th day. Our results indicated that the treatment with a LED system was clearly effective in reducing the number of inflammatory cells and improving the healing process in an experimental model of third-degree burnings.     

The biology of burn injury

Please cite this paper as: The biology of burn injury. Experimental Dermatology 2010; 19 : 777–783. Abstract: Burn injury is a complex traumatic event with various local and systemic effects, affecting several organ systems beyond the skin. The pathophysiology of the burn patient shows the full spectrum of the complexity of inflammatory response reactions. In the acute phase, inflammation mechanism may have negative effects because of capillary leak, the propagation of inhalation injury and the development of multiple organ failure. Attempts to mediate these processes remain a central subject of burn care research. Conversely, inflammation is a necessary prologue and component in the later‐stage processes of wound healing. In this review, we are attempting to present the current science of burn wound pathophysiology and wound healing. We also describe the evolution of innovative strategies for burn management.     

Sensitivity of Staphylococcus aureus and Streptococcus pyogenes Isolated from Skin Infections in 1992 to Antimicrobial Agents

We studied the efficacy of antimicrobial agents against Staphylococcus aureus (S. aureus) and Streptococcus pyogenes (S. pyogenes) isolated from skin infections in 1992. For S. aureus, we measured the minimum inhibitory concentrations (MICs) of the following 10 drugs: methicillin (DMPPC), cefaclor (CCL), gentamicin (GM), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), vancomycin (VAN), fusidic acid (FA), ofloxacin (OFLX) and nadifloxacin (NDFX); for S. pyogenes, we determined the MICs of the following 9 drugs: ampicillin (ABPC), amoxicillin (AMPC), cefpodoxime proxetil (CPDX-PR), erythromycin (EM), clindamycin (CLDM), minocycline (MINO), norfloxacin (NFLX), ofloxacin (OFLX) and nadifloxacin (NDFX). These drugs are frequently used to treat skin infections, either systemically or topically. NDFX is a new synthetic fluoroquinolone, recently developed for use as a topical acne medication in Japan. It is used NDFX for acne, but not for skin infections. There were no strains of S. aureus resistant to NDFX, VAN or FA. The resistance (≧12.5 µg/ml) of S. aureus was highest to GM and lowest to OFLX. Four strains of methicillin-resistant (≧12.5 µg/ml) S. aureus (MRSA) were found. In contrast, no resistant strains of S. pyogenes were found except to MINO. Only two strains of S. pyogenes were susceptible to MINO. The sensitivity of S. pyogenes to ABPC, AMPC, CPDX-PR, EM and CLDM was very good. All the strains were susceptible at a MIC below ≧0.05 µg/ml. However, the S. pyogenes strains were not very sensitive to the new quinolones, especially NFLX. We concluded that penicillins, cephalosporins and macrolides are still effective against streptococcal infections. In contrast, we found S. aureus to be resistant to several kinds of antimicrobial agents. Accordingly, we need to check the sensitivity of S. aureus, before using antimicrobial agents for staphylococcal infections. Roughly speaking, the drugs that are strongly effective against S. aureus are not effective against S. pyogenes. For example, the efficacy of MINO against S. aureus was very good, but almost all S. pyogenes strains were resistant to it. The pattern is much the same for the new quinolones.     

Evaluation of in vitro activity of ciclopirox olamine,butenafine HCl and econazole nitrate against dermatophytes,yeasts and bacteria

Background In many instances, a cutaneous fungal infection may exist concomitantly with bacterial involvement. In this study we compared the in vitro activity of three antifungal agents against the dermatophytes, yeasts and bacteria recovered most commonly from cutaneous mycoses and bacterial infections. Methods Using a microdilution method adapted from the National Committee for Clinical Laboratory Standards (NCCLS), we determined the minimum inhibitory concentrations (MICs) of ciclopirox olamine, econazole nitrate and butenafine HCl against a panel of dermatophyte fungi and yeasts (n = 39) and bacterial isolates (n = 45). Results All three antifungals demonstrated comparable activity against the dermatophytes tested, with a MIC range of 0.03–0.25 µg/ml for ciclopirox, < 0.001–0.25 µg/ml for econazole and 0.03–0.25 µg/ml for butenafine. For yeasts, ciclopirox showed activity against all isolates, with an MIC range of 0.001–0.25 µg/ml, whereas econazole had a broader range of 0.125–> 0.5 µg/ml. Butenafine displayed limited activity against the yeast Candida albicans and no activity against Malassezia furfur. For the antibacterial activity studies, ciclopirox demonstrated activity against all isolates tested with a range of 0.06–2 µg/ml, while econazole showed activity against Gram‐positive bacteria only, with a MIC range of 0.004–0.25 µg/ml. Butenafine HCl had a limited activity against bacterial isolates tested, showing activity against β‐hemolytic Streptococcus Group A and Corynebacterium only. Neither econazole nitrate nor butenafine HCl demonstrated activity against any of the Gram‐negative strains evaluated in this study. Conclusions The data suggest that ciclopirox olamine has the broadest in vitro activity, in comparison to econazole and butenafine HCl, against bacteria, yeasts and bacteria. These findings may have implications in the use of these antimycotics in the treatment of mixed cutaneous infections where bacteria or yeasts are present in addition to dermatophytes.     

Effect of silver-containing hydrofiber dressing on burn wound healing: A meta-analysis and systematic review

Background

Silver sulfadiazine is commonly used to treat local burn wounds. Aquacel-Ag is a hydrogen fiber dressing containing ionic silver that reduces burn wound infection and promotes antimicrobial activity. It is necessary to compare the efficacy of the two in the healing of burns.

Aims

The aim of this study was to systematically evaluate the effect of Aquacel-Ag on burn wound healing.

Methods

A computerized search of CNKI, VIP, Wanfang, SinoMed, PubMed, Cochrane Library, EMbase, Science Direct, Web of Science, Wiley Online Library, and Open Access Library databases was performed from January 1, 2000 to December 31, 2021 for randomized controlled clinical trials. The trials on Aquacel-Ag dressing and silver sulfadiazine in the treatment of burns were selected. Meta-analysis was performed using Review Manager 5.0 software.

Results

Eleven articles were finally included, with 794 burn patients. Meta-analysis results showed that compared with patients treated with silver sulfadiazine, burn patients treated with Aquacel-Ag dressing had shorter wound healing time [MD = −2.49, 95% CI (−5.64–0.65), p = 0.12], significantly lower tumor necrosis factor-α (TNF-α) level [MD = −0.52, 95% CI (−0.82–0.22), p = 0.0008], higher wound healing rate [MD = 8.41, 95% CI (3.39–13.43), p = 0.001], fewer dressing changes [MD = −3.27, 95% CI (−4.90–1.63), p < 0.0001].

Conclusion

Aquacel-Ag dressing can shorten wound healing time and effectively reduce inflammatory reactions in burn patients compared with silver sulfadiazine, but their safety still needs further exploration and analysis.     

Optical coherence tomography angiography for longitudinal monitoring of vascular changes in human cutaneous burns

Assessment of vasculature is an important aspect of monitoring healing of cutaneous burn injuries. Recent advances in optical coherence tomography (OCT) have enabled it to be used to perform high‐resolution imaging of the cutaneous vasculature in vivo, with the potential to provide a superior alternative to the conventional assessment of scoring skin color. The goal of this study is to investigate the feasibility of OCT angiography for longitudinal monitoring of vasculature and identification of vascular features in human cutaneous burns. We integrate several OCT imaging protocols and image‐processing techniques into a systematic method for longitudinal monitoring and automatic quantification. The demonstration of this method on a partial‐thickness burn shows the accurate co‐location of longitudinal scans; characteristic vascular features in different healing phases; and eventual decrease of the elevated vasculature area density and vessel diameter to normal levels. Such a method holds promise for longitudinal monitoring of vasculature in burn injures as well as in other cutaneous vascular pathologies and responses to treatment.     

A Histological Study of Cutaneous Thermal Wounds Using a Clostridium perfringens-Derived Wound Healing Substance with Wound Healing Stimulation Activity

We studied the effects of a Clostridium perfringens-derived wound-healing substance (WHS) on the healing of thermal burn wounds. Third-degree burn injuries were inflicted on the back skin of rats. We histologically evaluated the effects of WHS ointments and compared them with those of lysozyme chloride ointment. We observed the formation of dermal collagen fibers and the increase of capillaries in the WHS ointment treated groups. From the results of hematoxylin and eosin staining and silver staining, an increase in capillaries was observed one week after the application of WHS ointment. Three weeks after the application, when the epithelization was in the final stage, capillary formation ceased. In the WHS ointment-applied groups, electron microscopic observation showed that new collagen fibers were regularly formed in the dermis. On the other hand, in the lysozyme chloride ointment-applied groups, new collagen fibers were present, but were irregularly formed. The main wound healing stimulative action of the WHS ointment could be due to its acceleration of new capillary formation.     

The effect of laser diode irradiation on wound healing of rat skin

Abstract

Background: Light amplification by stimulated emission of radiation (LASER) diode irradiation (LDI) has some beneficial effects on the wound healing. However, little is known about the biochemical effect of LDI on wound healing. We have performed animal study to clarify the effect of LDI on wound healing based on microscopic findings. Methods: Eight-month-old male rats (NTacSam:SD, SamtakoBioKorea), weighting 250–300 g, were used. Round blade, of 1 cm diameter, was penetrated through the skin and subcutaneous level after elevating the skin just above the thoracic spine of the rats. Laser diode of 655, 785, and 850 nm wavelengths were irradiated to the skin wound for 9 days, 20 min a day. Eight rats were used in each four groups including non-irradiated group. Immunochemical staining was carried out to evaluate pan-cytokeratin and actin, and Masson's trichrome staining was carried to evaluate the cellular and protein components relating to wound healing. Wound size was measured on 9th postoperative day with computer system. Result: Collagen formation was graded as 2+, 3+, and 4 + in the order of non-radiation group, 655, 785, and 850 nm irradiation groups, respectively. Myofibroblast was formed more abundantly in LDI group than in non-irradiated group. The mean values of proliferating cell nuclear antigen (PCNA) were 67.8 ± 5.0, 84.0 ± 4.6, 78.0 ± 6.8, and 74.2 ± 4.0 nm in the order of non-radiation group, 655, 785, and 850 nm irradiation groups, respectively. Mean values of defect size were 2,840 ± 124 um, 1,689 ± 125 um, 1,254 ± 94 um, and 1,423 ± 113 in the order of non-radiation group, 65, 785, and 850 nm groups, respectively. Conclusion: LDI has beneficial effects on the formation of fibroblast and collagen, and results in better wound healing.     

Formulation and evaluation of UV protective synbiotic skin care topical formulation

Objective: The objective of current study to investigate the photo protective potential of synbiotic formulation comprising of prebiotic and probiotic.

Methods: Selenium nanoparticles were synthesized by chemical reduction method and investigated for physical-chemical properties including morphology, physical state, and free radical scavenging potential. Selection of probiotic biomass was made on the free radical scavenging potential by using NO assay. A topical w/o emulsion-based cream was prepared with screened ingredients to achieve a stable product with optimum free radical scavenging potential. The finished product was investigated for various mechanical, physiochemical, and viscoelastic characteristics. The SPF of optimized formulation was determined in UV-stimulated Wistar rat model.

Results: Results indicated that the finished product shows nanoscale feature of elemental selenium. Cream comprising of potential free radical reagent (Selenium nanoparticles with IC₅₀ 50.097 µg/ml and biomass of Lactobacillus rhamnosus have IC₅₀ 61.63 µg/ml) exhibits a SPF of 29.77. Optimized skin care formulation has desirable physiochemical and viscoelastic properties required for topical application. Histopathology and Draize test indicated the finished product does not show any sign of skin toxicity.

Conclusion: Results inferred that topical formulation combining the features of selenium and probiotic biomass offer an effective alternative for the treatment of sunburn complications.     

小面积深Ⅱ°与Ⅲ°酸烧伤切削痂延期植皮术的临床研究

目的研究小面积深Ⅱ°与Ⅲ°酸烧伤临床切削痂后进行延期植皮手术的效果。方法2000年1月～2010年1月收住院的经手术植皮的小面积深Ⅱ°与Ⅲ°酸烧伤患者98例,随机分为2组,切削痂后直接植皮为对照组44例,延期植皮术处理为干预组54例。经治疗后对两组手术时间、皮下血肿率、创面细菌量、植皮成活率、创面愈合时间等进行比较分析。结果手术时间比较2组差异无统计学意义（P〉0．05）;干预组皮下血肿率低于对照组（P〈0．05）;干预组创面细菌量与对照组比较无明显增加（P〉0．05）;干预组植皮成活率高于对照组（P〈0．05）;干预组创面愈合时间短于对照组（P〈0．01）。结论小面积深Ⅱ°与Ⅲ°酸烧伤削痂后延期植皮术具有皮下血肿少,植皮成活率高,感染率低,愈合时间短等优点,是一种比较好的手术选择,综合效果优于立即植皮。     

Wound healing property of a gel prepared by the combination of Pseudomonas aeruginosa alginate and Alhagi maurorum aqueous extract in rats

Although alginate has been known to be a good wound dressing, it does not have antimicrobial properties, has low availability, and is expensive. To overcome these problems, the present study was conducted, where the extraction of this material from an available small factory Pseudomonas aeruginosa and the improvement of its wound healing property by its combination with herb extract, Alhagi maurorum, done. Nineteen P. aeruginosa strains were isolated and identified from burned skin, and the one isolated strain with the highest ability of alginate production was selected. A. maurorum aqueous extract was prepared, and the toxicity of each material was determined using the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5diphenyltetrazolium bromide assay. A mixture of nontoxic doses of each substance was then prepared. Thirty‐two Wistar rats were divided into four groups (n = 8). The control group and the rest three groups, which were treated by alginate, A. maurorum extract, and alginate‐ A. maurorum extract. Throughout the 21 days of treatment, the open wound sites were checked. Finally, the rats were sacrificed and the effect of each substance on their skin tissue was evaluated. The results showed that the high alginate production without any toxic effect was obtained from the P. aeruginosa strain K1. A. maurorum aqueous extract had dose‐dependent toxicity. The aqueous solution of alginate‐ A. maurorum extract complex group showed the best wound healing activity in both macroscopic and microscopic examinations. Recent research has introduced a new type of wound dressing with high wound healing properties. This could decrease the time for re‐epithelialization and increase wound contraction percentage.     

Effect of low-level laser therapy (660 nm) on the healing of second-degree skin burns in rats

The aim of this study was to investigate the effects of 660 nm laser on the healing of burn wounds made on the backs of rats. Thirty-two Wistar male rats were used. The animals were randomly distributed into 2 groups of 16 animals each: control group (burned rats without treatment) and laser-treated group (burned rats treated with laser therapy). Each group was divided into two different subgroups, euthanized in different periods (subgroup A: 7 days post-surgery and subgroup B: 14 days post-surgery). Histopathological analysis revealed a significant decrease in the necrotic area in the laser-treated group compared to the controls at days 7 and 14 post-injury. COX-2 positive cells were found in a strong pattern in the group submitted to laser therapy after 7 days. Regarding VEGF immunomarker, a significant VEGF immunoexpression was detected in the laser-exposed group after 14 days when compared to the negative control group. Taken together, our results demonstrate that laser therapy is able to promote skin repair of burned rats as a result of decreasing necrotic area and an up-regulation of COX-2 and VEGF immunoexpression.     

Black tattoo inks are a source of problematic substances such as dibutyl phthalate

Background. Tattooing has recently become increasingly popular. Using tiny needles, tattooists place the tattoo ink in the dermis along with numerous unknown ingredients. Most tattoos consist of black inks, which are predominantly composed of soot products (carbon black with polycyclic aromatic hydrocarbons). Objectives. Black tattoos cause skin problems, including allergic reactions, but the responsible substance frequently remains unknown. Material/methods. We applied gas chromatograph–mass spectrometry analysis to search for hazardous compounds in 14 different commercially available black tattoo ink samples. Results. The analysis revealed that all inks contained the softener substance dibutyl phthalate (0.12–691.2 µg/g). Some of the inks contained hexachloro‐1,3‐butadiene (0.08–4.52 µg/g), metheneamine (0.08–21.64 µg/g), dibenzofuran (0.02–1.62 µg/g), benzophenone (0.26–556.66 µg/g), and 9‐fluorenone (0.04–3.04 µg/g). Conclusion. The sensitizing agent dibutyl phthalate acts directly on keratinocytes and can drive Th2 responses following skin exposure via induction of thymic stromal lymphopoietin gene expression. Hexachloro‐1,3‐butadiene is genotoxic in vitro and 9‐fluorenone is cytotoxic, generating reactive oxygen species under light exposure. The substances found in the inks might be partially responsible for adverse skin reactions to tattoos.     

Effects of all-trans retinoic acid and sodium lauryl sulphate on the permeability of human skin in vitro

Recent in vivo investigations have shown that pretreatment with topical all-trans retinoic acid (RA) may diminish the skin response to sodium lauryl sulphate (SLS). This study evaluated the permeation of SLS through human skin after pretreatment with RA, and vice versa, by in vitro methods. The permeability coefficient of SLS (3.24 ± 0.21 × 10³ cm/h) and the 24-h cumulative amount of SLS (3.41 ± 0.6% of dose applied) permeating RA-pretreated skin did not differ significantly from those across untreated skin (control) (P > 0.05). In contrast, the permeability coefficient of RA (0.23 ± 0.05 × 10³ cm/h) and its 24-h cumulative amount (0.37 ± 0.05% of dose applied) penetrating SLS-pretreated skin were significantly greater than those permeating untreated skin (P<0.05). Thus, an increase in RA penetration was induced by SLS pretreatment; however, pretreating the skin with RA did not inhibit the percutaneous permeation of SLS. Based on previous in vivo findings where RA reduced skin reactions to SLS,⁸ one would speculate that RA pretreatment may decrease SLS penetration. However, these penetration data do not necessarily uphold this presumption. Perhaps, other interactions between the substances and the skin, e.g. at cellular levels, may be responsible for the differing skin responses.     

Effect of Arnebia euchroma ointment on post-laser wound healing in rats

Introduction: Arnebia euchroma ointment has been used in Iranian Traditional Medicine for burn wound healing. The aim of this study is to evaluate wound healing efficacy of A. euchroma ointment on wounds induced after fractional CO₂ laser in rats.

Material and methods: In this study, after anesthetizing two bilateral burn wounds were induced on dorsal skin of the rat using fractional ablative CO₂ laser. After applying laser, A. euchroma ointment, petrolatum, and silver sulfadiazine cream were used topically on wounds twice daily for 10 days. Digital photographs were captured from the wound surfaces every day. At the end of the study, two blinded dermatologists observed the photograph of 3rd, 5th, 7th, and 9th days after laser injury and assessed erythema, crusting/scabbing, epithelial confluence, and general wound appearance to determine the efficacy of wound healing. These wound-healing parameters were assessed using the 5-point scales.

Results: This study showed significantly less erythema and crusting (P = 0.024 and P = 0.004, respectively) on 9th day and higher epithelial confluence and general wound appearance scores on 7th (P = 0.037 and p = 0.016, respectively) and 9th days (P = 0.008 and P = 0.016, respectively) in A. euchroma ointment compared with other groups.

Conclusion: This study showed A. euchroma ointment has good healing effects on post-laser wounds in rats.