Rat Skin Tissue Research Articles

Exploring the potential mechanisms of the ethyl acetate fraction of Hippophae rhamnoides L. seeds as a natural healing agent for wound repair

Ethnopharmacological relevanceSea buckthorn (Hippophae rhamnoides L.) has been designated a "medicine food homology" fruit by the National Health Commission of China due to its nutritional value. In traditional Chinese ethnomedicine, Hippophae rhamnoides L. is commonly used to treat nonhealing wounds such as burns, sores, and gastric ulcers. The aim of this study was to explore the healing effects of the ethyl acetate extract of sea buckthorn seeds (SBS-EF) on burn wounds. Aim of the studyThe primary objectives of this research were to determine the most effective medicinal site of action for treating burns with sea buckthorn seeds (SBS) and to investigate the underlying material basis and mechanisms of their therapeutic effects. Materials and methodsThe effects of different components of SBS-EF on the proliferation and migration of human skin fibroblasts (HSFs) were evaluated via MTT assays, scratch assays, transwell assays, and hydroxyproline secretion analysis. SBS-EF displayed the greatest activity amongst the extracts. Subsequent analyses included network pharmacology methodology, molecular docking studies, ultraperformance liquid chromatography UPLC-Orbitrap-Exploris-120-MS and a severe second-degree burn rat model to investigate the chemical constituents and potential therapeutic mechanisms of the SBS-EF. ResultsIn vitro studies demonstrated the efficacy of SBS-EF in promoting HSF growth and migration. UPLC-Orbitrap-Exploris-120-MS analysis revealed that SBS-EF had ten major constituents, with flavonoids being the predominant compounds, especially catechin, quercetin, and kaempferol derivatives. Network pharmacology and molecular docking analyses indicated that SBS-EF may exert its healing effects by modulating the Wnt/β-catenin signalling pathway. Subsequent in vivo experiments demonstrated that SBS-EF accelerated burn wound healing in rats, increased hydroxyproline expression in skin tissue, facilitated skin structure repair, and enhanced collagen production and organisation over a 21 d period. Additionally, exposure to SBS-EF upregulated WNT3a and β-catenin while downregulating GSK-3β levels in rat skin tissue. ConclusionsThe wound healing properties of SBS-EF were attributed to its ability to enhance HSF growth and migration, increase hydroxyproline levels in the skin, promote collagen accumulation, reduce scarring, and decrease the skin water content. SBS-EF may also provide therapeutic benefits for burns by modulating the Wnt/β-catenin signalling pathway, as evidenced by its effective site and likely mechanism of action in the treatment of burned rats.

A bitter flavonoid gum from Dorema aucheri accelerate wound healing in rats: Involvement of Bax/HSP 70 and hydroxyprolin mechanisms.

Dorema aucherigum (DAG) is a bitter flavonoid gum widely used for numerous medicinal purposes including wound recovery. The present work investigates the acute toxicity and wound-healing effects of DAG in excisional skin injury in rats. Sprague Dawley rats (24) were clustered into four groups, each rat had a full-thickness excisional dorsal neck injury (2.00cm) and addressed with 0.2mL of the following treatments for 15 days: Group A (vehicle), rats addressed with normal saline; Group B, rats received intrasite gel; C and D, rats addressed with 250 and 500mg/kg of DAG, respectively. The results revealed the absence of any toxic signs in rats who received oral dosages of 2 and 5g/kg of DAG. Wound healing was significantly accelerated following DAG treatments indicated by smaller open areas and higher wound contraction percentages compared to vehicle rats. Histological evaluation revealed higher fibroblast formation, collagen deposition, and noticeably lower inflammatory cell infiltration in granulated skin tissues of DAG-addressed rats compared to vehicle rats. DAG treatment caused significant modulation of immunohistochemical proteins (decreased Bax and increased HSP 70) and inflammatory mediators (reduced TNF-α, IL-6, and magnified IL-10), which were significantly varied compared to vehicle rats. Moreover, topical DAG treatment led to significant upregulation of the hydroxyproline (HDX) (collagen) and antioxidant content. At the same time, decreased the lipid peroxidation (MDA) levels in healed tissues obtained from DAG-treated rats. The present wound contraction by DAG might be linked with the modulatory effect of its phytochemicals (polysaccharides, flavonoids, and phenolic) on the cellular mechanisms, which justify their folkloric use and provokes further investigation as therapeutic drug additives for wound contraction.

Validation of UV–Vis spectrophotometric and colorimetric methods to quantify methotrexate in plasma and rat skin tissue: Application to in vitro release, ex vivo and in vivo studies from dissolving microarray patch loaded pH-sensitive nanoparticle

This research transformed MTX into smart nanoparticles that respond to the acidic conditions present in inflammation. These nanoparticles were then incorporated into a patch that dissolves over time, aiding their penetration. A method using UV–Vis spectrophotometry was validated to support the development of this new delivery system. This method was used to measure the quantity of MTX in the prepared patches in various scenarios: in laboratory solutions with pH 7.4 and pH 5.0, in skin tissue, and plasma. This validation was conducted in laboratory studies, tissue samples, and live subjects, adhering to established guidelines. The resulting calibration curve displayed a linear relationship (correlation coefficient 0.999) across these scenarios. The lowest quantity of MTX that could be accurately detected was 0.6 µg/mL in pH 7.4 solutions, 1.46 µg/mL in pH 5.0 solutions, 1.11 µg/mL in skin tissue, and 1.48 µg/mL in plasma. This validated method exhibited precision and accuracy and was not influenced by dilution effects. The method was effectively used to measure MTX levels in the developed patch in controlled lab settings and biological systems (in vitro, ex vivo, and in vivo). This showed consistent drug content in the patches, controlled release patterns over 24 h, and pharmacokinetic profiles spanning 48 h. However, additional analytical approaches were necessary for quantifying MTX in studies focused on the drug's effects on the body's functions.

Dehydration-Toughing Dual-Solvent Gels with Viscoelastic Transition for Infectious Wound Treatment.

The modulus of traditional biomedical hydrogels increases exponentially meditated by dehydration-stiffing mechanism, which leads to the failure of interface matching between hydrogels and soft tissue wounds. It is found in the study that the dual-solvent gels exhibit dehydration-toughening mechanism with the slowly increasing modulus that are always match the soft tissue wounds. Therefore, dual-solvent glycerol hydrogels (GCFen-gly DGHs) are prepared with hydrophobically modified catechol chitosan (hmCSC) and gelatin based on the supramolecular interactions. GCFen-gly DGHs exhibit excellent water retention capacity with a total solvent content exceeding 80%, permanent skin-like modulus within a range of 0.45 to 4.13kPa, and stable photothermal antibacterial abilities against S, aureus, E. coli, as well as MRSA. Infectious full-thickness rat skin defect model and tissue section analysis indicate that GCFen-gly DGHs are able to accelerate infectious wound healing by alleviating the inflammatory response, promoting granulation tissue growth, re-epithelialization, collagen deposition, and vascular regeneration. As a result, GCFen-gly DGHs is expected to become the next-generation biological gel materials for infectious wound treatment.

H2S donor S-propargyl-cysteine for skin wound healing improvement via smart transdermal delivery.

Hydrogen sulfide for wound healing has drawn a lot of attention recently. In this research, the S-propargyl-cysteine (SPRC), an endogenous H2S donor, was loaded on carbomerhydrogel, and a copper sheet rat burn model was developed. Pathological changes in rat skin tissue were examined using hematoxylin-eosin (HE) and Masson staining. The immunohistochemistry (IHC) staining was performed to detect the expression of Collagen I (Col I) and Collagen III (Col III). The mRNA levels of interleukin (IL)-6, Col Iα2, Col IIIα1, tissue inhibitors of metalloproteinase (TIMP)-1, matrix metalloproteinase (MMP)-9, vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β1 were examined by quantitative real-time chain polymerase reaction. The findings demonstrated that the collagen layer was thicker in the SPRC group during the proliferative phase, SPRC hydrogel promoted VEGF expression. In the late stage of wound healing, the expression of IL-6, TIMP-1, MMP-9, and TGF-β1 was inhibited, and the Col I content was closer to that of normal tissue. These results surface that SPRC hydrogel can promote wound healing and play a positive role in reducing scar formation. Our results imply that SPRC can facilitate wound healing and play a positive role in reducing scar formation.

Fluorescent microscopy evaluation of diode laser effect on the penetration depth of turmeric (Curcuma longa) extract cream on skin tissues of Wistar rats.

The study investigates the effect of diode laser exposure on curcumin's skin penetration, using turmeric extraction as a light-sensitive chemical and various laser light sources. It uses an in vivo skin analysis method on Wistar strain mice. The lasers are utilized at wavelengths of 403nm, 523nm, 661nm, and 979nm. The energy densities of the lasers are 20.566J/cm2, 20.572J/cm2, 21.162J/cm2, and 21.298J/cm2, which are comparable to one another. The experimental animals were divided into three groups: base cream (BC), turmeric extract cream (TEC), and the combination laser (L), BC, and TEC treatment group. Combination light source (LS) with cream (C) was performed with 8 combinations namely 523nm ((L1 + BC) and (L1 + TEC)), 661nm ((L2 + BC) and (L2 + TEC)), 403nm ((L3 + BC) and (L3 + TEC)), and 979nm ((L4 + BC) and (L4 + TEC)). The study involved applying four laser types to cream-covered and turmeric extract-coated rat skin, with samples scored for analysis. The study found that both base cream and curcumin cream had consistent pH values of 7-8, within the skin's range, and curcumin extract cream had lower viscosity. The results of the statistical analysis of Kruskal-Wallis showed a significant value (p < 0.05), which means that there are at least two different laser treatments. The results of the post hoc analysis with Mann-Whitney showed that there was no significant difference in the LS treatment with the addition of BC or TEC when compared to the BC or TEC treatment alone (p > 0.05), while the treatment using BC and TEC showed a significant difference (p < 0.05). Laser treatment affects the penetration of the turmeric extract cream into the rat skin tissue.

Long noncoding RNA XIST promotes cell proliferation and migration in diabetic foot ulcers through the miR-126-3p/EGFR axis

BackgroundThe prevalence of diabetic foot ulcers (DFUs) has caused serious harm to human health. To date, a highly effective treatment is lacking. Long noncoding RNA X-inactive specific transcript (lncRNA XIST) has been the subject of mounting research studies, all of which have found that it serves as a protective factor against certain diseases; however, its function in DFUs is not entirely understood. This study was performed to determine the importance of the lncRNA XIST in the pathogenesis and biological function of DFUs.MethodsDiabetic ulcer skin from rats was analysed using haematoxylin-eosin (HE), Masson’s trichrome, and immunohistochemistry (IHC) staining. The differences in the expression of genes and proteins were examined with real-time quantitative polymerase chain reaction (RT–qPCR) and Western blotting. Next, the interaction was verified with a dual luciferase gene reporter assay. In addition, CCK-8, Transwell, and wound healing assays were used to assess the proliferation and migration of HaCaT cells.ResultsThe lncRNA XIST and epidermal growth factor receptor (EGFR) were downregulated, while microRNA-126-3p (miR-126-3p) was increased in diabetic ulcer rat skin tissues and high glucose-induced HaCaT cells. In addition, we found that the lncRNA XIST binds to miR-126-3p and that EGFR is directly targeted by miR‑126‑3p. Silencing XIST contributed to upregulated miR-126-3p expression, thus lowering EGFR levels and inhibiting the proliferative and migratory abilities of high glucose-treated HaCaT cells; however, the miR-126-3p inhibitor and overexpression of EGFR reversed this effect.ConclusionDecreased lncRNA XIST expression inhibits the proliferative and migratory abilities of high glucose-induced HaCaT cells by modulating the miR-126-3p/EGFR axis, causing delayed wound healing.

HISTOPATOLOGICAL CHANGES OF WHITE RATS' SKIN CAUSED BY APPLICATION OF MIMOSIN FROM SIMPLISIA OF THE LAMTORO LEAF

Mimosine is one of the substances contained in lamtoro (Leucaena leucocephala) leaves. The toxic effect of mimosine on livestock is highly dependent on the concentration of mimosine in feed ingredients and the length of time livestock consume feed high in mimosine. This study aims to determine the histopathology of white rat skin exposed to mimosine compounds with different doses. This study used male white rats with Wistar strain, 2 months old and 300-350 g body weight. The 20 rats used were divided into four treatment groups, namely P0 (negative control, P1 (positive control, given standard mimosine 5 mg/head/day), P2 (given lamtoro leaf simplisia at a dose of 50 mg/head/day orally), P3 (given lamtoro leaf simplisia at a dose of 150 mg/head/day). On the 15th day of necropsy, the skin organs were taken and fixed using 10% NBF. After the skin organs were fixed, histopathology preparations were made using HE staining. Histopathologic examination was performed including three lesion variables: hair follicle necrosis, congestion, and inflammation. The severity of the lesions was scored as 0, 1, 2, and 3 for normal, mild, moderate and severe lesions, respectively. Data were then analyzed using Kruskal-Wallis and Mann-Whitney non-parametric tests. The results showed that exposure to mimosine from lamtoro leaf simplisia did not cause hair loss in experimental animals as it does in cattle. However, exposure to mimosine in P1 (5 mg/head/day) and P3 (150 mg/head/day) caused histopathological skin lesions in the form of congestion, necrosis, and mild inflammation. The results showed that exposure to mimosine from lamtoro leaf simplisia did not cause hair loss in experimental animals as it does in cattle. However, exposure to mimosine in P1 (5 mg/head/day) and P3 (150 mg/head/day) caused histopathological skin lesions in the form of congestion, necrosis, and mild inflammation. The conclusion of the study is that mimosine compounds from lamtoro leaf simplisia cause histopathological changes in white rat skin tissue, especially congestion lesions. However, there was no difference in the effect of mimosine administration from lamtoro leaf simplisia between a dose of 50 mg/head/day and a dose of 150 mg/head/day on the histopathology of rat skin tissue. Further research needs to be done on the effect of exposure to mimosine from lamtoro leaf simplisia with higher concentrations.

Preventive effect of human umbilical cord mesenchymal stem cells on skin aging in rats

The irreversibility of aging makes anti-aging become an important research direction in the field of medical research. As the most direct manifestation of human aging, skin aging has been paid more and more attention. Stem cells have been used as a basis for anti-aging studies in skin, of which adipose-derived mesenchymal stem cells are more commonly used. In this study, human umbilical cord mesenchymal stem cells were used, and human umbilical cord mesenchymal stem cells were intervened while making a skin aging model, which was planned to reduce the process of preventing skin aging in the study method. At the end of the experiment, rat skin and serum were taken for relevant data detection. The results showed that the contents of EGF and VEGF in serum and skin tissue of rats increased and the content of MDA decreased after the application of human umbilical cord mesenchymal stem cells. At the same time, hUCMSC intervention increased skin thickness, increased dermal vessels, increased type I collagen type III collagen mRNA expression, and decreased MMP-1 content in rats. The results showed that hUCMSC could prevent skin aging in rats.

Preparation, In-vitro, and Ex-vivo Evaluation of Ondansetron Loaded Invasomes for Transdermal Delivery

Invasomes are newly developed types of nanovesicles. A vesicular drug delivery system is considered one of the approaches for transdermal delivery to enhance permeation and improve drug bioavailability. Ondansetron is a serotonin receptor antagonist used for treating vomiting associated with different clinical cases. The study aimed to prepare invasomal dispersions for improving permeation of ondansetron across the skin with a controlled release pattern. Twenty-seven formulas of ondansetron-loaded invasomes were prepared by a modified mechanical dispersion method. These formulas were optimized by studying the effect of variables on entrapment efficiency. Vesicle size, polydispersity, zeta potential, in-vitro release and ex-vivo permeation studies were done for the optimized formulas. The selected formula was )F25( had )88.24%±0.04 (entrapment, (317.7 nm) vesicle size, (0.29) polydispersity, and (-31.5mV) zeta potential. In-vitro release study showed That (F25) had 75% release after (12) hrs., and dissolution followed the Korsmeyer-Peppas model with anomalous diffusion. Ex-vivo permeation study showed steady-state flux was 340.2 µg/cm2.hr with no lag time using rat skin tissue. A transmission electron microscope was done to visualize the selected formula. Invasomes are considered promising drug delivery systems for transdermal delivery of ondansetron, ensuring efficient permeation with a sustained release pattern.

Application of Several Special Staining Methods for Paraffin Sections on Epon-Embedded Semithin Sections

Aim: This study aimed to compare several specific staining protocols recommended for paraffin sections and toluidine blue and light green double staining combination to be tried for the first time with routine toluidine blue staining on semithin epon sections.&#x0D; Material and Methods: Samples of 1x1x1 mm were taken from the liver, skin, and aorta tissues of Wistar albino adult rats. Tissue samples were fixed with 5% glutaraldehyde at +4º C overnight, postfixed with 1% osmium tetroxide for one hour, and then, blocked with Epon 812 after processing. Semithin sections of 1 μm thickness were obtained from the epon blocks. Sections were stained with Altmann’s method (for mitochondria), Verhoeff’s method (for elastic fibers), Gordon&amp;Sweets’ silver impregnation method (for type III collagen), toluidine blue and light green double staining combination (for type I collagen) and routine toluidine blue method.&#x0D; Results: In liver sections, mitochondria in hepatocytes were differentiated by the Altmann method, and stromal type III collagen fibers were distinguished with Gordon&amp;Sweets’ method. Elastic lamellar structures were easily observed in black in the aortic sections stained with the Verhoeff method. Successful results were obtained in the staining of dermal type I collagen with toluidine blue and light green double staining in skin sections.&#x0D; Conclusion: Since the specific staining tried for the first time gave positive results in epon sections, it was concluded that these methods can be used to determine the localization of cellular and intercellular components that are aimed to be examined at the ultrastructural level.

Gynura divaricata (L.) DC. promotes diabetic wound healing by activating Nrf2 signaling in diabetic rats

The ethnopharmacological significanceDiabetic chronic foot ulcers pose a significant therapeutic challenge as a result of the oxidative stress caused by hyperglycemia. Which impairs angiogenesis and delays wound healing, potentially leading to amputation. Gynura divaricata (L.) DC. (GD), a traditional Chinese herbal medicine with hypoglycemic effects, has been proposed as a potential therapeutic agent for diabetic wound healing. However, the underlying mechanisms of its effects remain unclear. Aim of the studyIn this study, we aimed to reveal the effect and potential mechanisms of GD on accelerating diabetic wound healing in vitro and in vivo. Materials and methodsThe effects of GD on cell proliferation, apoptosis, reactive oxygen species (ROS) production, migration, mitochondrial membrane potential (MMP), and potential molecular mechanisms were investigated in high glucose (HG) stimulated human umbilical vein endothelial cells (HUVECs) using CCK-8, flow cytometry assay, wound healing assay, immunofluorescence, DCFH-DA staining, JC-1 staining, and Western blot. Full-thickness skin defects were created in STZ-induced diabetic rats, and wound healing rate was tracked by photographing them every day. HE staining, immunohistochemistry, and Western blot were employed to investigate the effect and molecular mechanism of GD on wound healing in diabetic rats. ResultsGD significantly improved HUVEC survival, decreased apoptosis, lowered ROS production, restored MMP, improved migration ability, and raised VEGF expression. The use of Nrf2-siRNA completely abrogated these effects. Topical application of GD promoted angiogenesis and granulation tissue growth, resulting in faster healing of diabetic wounds. The expression of VEGF, CD31, and VEGFR was elevated in the skin tissue of diabetic rats after GD treatment, which upregulated HO-1, NQO-1, and Bcl-2 expression while downregulating Bax expression via activation of the Nrf2 signaling pathway. ConclusionThe findings of this study indicate that GD has the potential to serve as a viable alternative treatment for diabetic wounds. This potential arises from its ability to mitigate the negative effects of oxidative stress on angiogenesis, which is regulated by the Nrf2 signaling pathway. The results of our study offer valuable insights into the therapeutic efficacy of GD in the treatment of diabetic wounds, emphasizing the significance of directing interventions towards the Nrf2 signaling pathway to mitigate oxidative stress and facilitate the process of angiogenesis.

Validation of spectrophotometric and colorimetric methods to quantify clindamycin in skin tissue: application to in vitro release and ex vivo dermatokinetic studies from separable effervescent microarray patch loaded bacterially sensitive microparticle.

Diabetes mellitus can cause diabetic foot infection (DFI) complications. DFI is generally caused by infection from bacteria and Methicillin-Resistant Staphylococcus aureus (MRSA) which is resistant to several antibiotics. Application therapy of clindamycin (CLY) administration with the oral route has low bioavailability and non-selective distribution of antibiotics towards bacteria intravenously. In this research, CLY was developed into bacterially sensitive microparticles (MPs) which were further incorporated into a separable effervescent microarray patch (SEMAP) system to increase the selective and responsive to DFI-causing bacteria of CLY. To support this formulation, we explore the potential of silver nanoparticles (AgNPs) towards the UV-Vis spectrophotometry method. The analytical method was validated in phosphate-buffered saline (PBS), tryptic soy broth (TSB), and skin tissue to quantify CLY, CLY loaded in microparticle, and SEMAP system. The developed analytical method was suitable for the acceptance criteria of ICH guidelines. The results showed that the correlation coefficients were linear ≥ 0.999. The values of LLOQ towards PBS, TSB, and skin tissue were 2.02µg/mL, 4.29µg/mL, and 2.31µg/mL, respectively. These approaching methods were also found to be accurate and precise without being affected by dilution integrity. The presence of Staphylococcus aureus bacteria culture can produce lipase enzymes that can lysing the microparticle matrix. Drug release studies showed that bacterial infection in the high drug release microparticle sensitive bacteria and high drug retention in ex vivo dermatokinetic in rat skin tissue media. In addition, in vivo studies were required to quantify the CLY inside in further analytical validation methods.

The Effect of Giving Aloe Vera Gel on Collagen Growth in Wistar Rats (Rattus Norvegicus) with Exposure to Ultra Violet-B Light

Exposure to UV rays can cause photochemical damage to the DNA of cells in the body, triggering cancer formation, especially skin cancer in humans. The skin may lose elasticity. Research is needed to ensure that currently, we are still looking for plants or foods that contain collagen, which can prevent wrinkles. This research is an original experiment carried out in a laboratory. Two types of variables play a role in this research: independent variables and dependent variables. In this experiment, aloe vera gel was used as an independent variable as a substitute for UVB light exposure. Collagen development, measured in mouse skin, is the dependent variable here. This study found that the standard control group had no collagen growth and was stable. This was because the typical control treatment was not exposed to UVB rays; hence, collagen formation was stable. The group administered 15% aloe vera extract gel had a more substantial effect on rat skin tissue collagen development after UVB light exposure than the 5% and 10% groups. This is because a higher dose of aloe vera extract includes more chemical components that promote mouse skin collagen formation.

Topical application of cocoa extract (Theobroma cacao L.) to prevent photoaging by increasing superoxide dismutase levels on wistar rats skin exposed to ultraviolet light A

Background: The latest trend in anti-aging prevention is projected through the use of antioxidants derived from natural ingredients with minimal side effects compared to chemicals. Cocoa bean (Theobroma cacao L.) is one of the sources of natural antioxidants with high flavonoid antioxidant content. This study aims to determine the effect of topical application of cocoa extract to prevent photoaging in wistar rats exposed to ultraviolet A (UVA) light. Methods: Experimental research with animal models using 36 wistar rats exposed to UVA and divided into 2 groups, given 10% cocoa extract cream and basic cream on the back area. The parameters assessed were superoxide dismutase (SOD) levels in skin tissue. Comparative analysis with independent T-test using SPSS version 21 to compare SOD levels of both groups. Results: Superoxide dismutase levels in both groups were found to be normally distributed (p&gt; 0.05). The results of the comparative test with the Independent T-test found that the mean SOD levels of the treatment group were higher than those of the control group at 8.07 ± 1.99 ng/ml and 5.04 ± 1.54 ng/ml (p&lt; 0.001; 95% CI: 1.82-4.24). Conclusion: Topical application of 10% cocoa extract cream on the skin of Wistar rats exposed to UVA light resulted in higher levels of superoxide dismutase in the rat skin tissue than the control.

Desmopressin enhances random-pattern skin flap survival in rats: Possible role of vasopressin Type-1a and 2 receptors

BackgroundMany drugs have been explored for their role in improving skin flap survival. 1-deamino-8-D-arginine vasopressin (DDAVP or desmopressin) is a synthesized form of anti-diuretic hormone (ADH) and a selective agonist for vasopressin type-2 receptors (V2 receptors). Desmopressin has been shown to improve endothelial function, induce vasodilation, and reduce inflammation. We aimed to evaluate its efficacy in enhancing flap survival and assess the role of vasopressin receptors in this process. Materials and methodsWe randomly assigned six male Wistar rats to each study group. Different doses of desmopressin were injected intraperitoneally to find the most effective amount (8 μg/rat). SR-49059, a selective V1a receptor antagonist, was given at 2μg/rat before providing the most effective dose of desmopressin (8μg/rat). Histopathological assessments, quantitative measurements of interleukin-1β (IL-1β), Tumor necrosis factor-alpha (TNF-α), and Nuclear Factor-κB (NF-κB), optical imaging, and measurement of the expression levels of V2 receptor in the rat skin tissue were performed. ResultsDesmopressin (8μg/rat) significantly reduced the mean percentage of necrotic area compared to the control group (19.35% vs 73.57%). Histopathological evaluations revealed a notable reduction in tissue inflammation, edema, and degeneration following administration of desmopressin (8). The expression of the V2 receptor was increased following desmopressin administration. It also led to a reduction in IL-1β, TNF-α, and NF-κB levels. The protective effect of desmopressin on flap survival was reversed upon giving SR-49059. The optical imaging revealed enhanced blood flow in the desmopressin group compared to the control group. ConclusionsDesmopressin could be repurposed to improve flap survival. V1a and V2 receptors probably mediate this effect.

Potential roles of circulating microRNAs in the healing of type 1 diabetic wounds treated with green tea extract: molecular and biochemical study

BackgroundCirculating miRNAs have been implicated in various aspects of diabetic wound healing, including inflammation, angiogenesis, and extracellular matrix remodeling. Thus, in alternative herbal medicine strategies, miRNAs will be potential therapeutic molecular targets in nonhealing wounds. These could be valuable elements for understanding the molecular basis of diabetic wound healing and could be used as good elements in bioinformatics. ObjectivesTo elucidate the molecular mechanisms of microRNAs in association with apoptosis-inducing genes in controlling skin wound healing in diabetic wounds treated with green tea polyphenols (GTPs). MethodsGreen tea hydro extract (GTE) at doses of100–200 mg/ml was topically applied to the skin tissues of rats with T1DM induced by a single dose of streptozotocin (STZ; 100 mg/kg, in 0.01 M sodium citrate, pH 4.3–4.5) injected intraperitoneally for seven consecutive days to induce T1DM. The rats were treated with green tea for three weeks. A sterile surgical blade was used to inflict a circular wound approximately 2 cm in diameter on the anterior-dorsal side of previously anesthetized rats by a combination of ketamine hydrochloride (50 mg/kg, i.e., body weight) and xylazine hydrochloride. Afterward, the molecular roles of the circulating miRNAs miR-21, miR-23a, miR-146a, and miR-29b and apoptotic genes were determined by quantitative real-time PCR to evaluate Bax, Caspase-3, and Bcl-2 in wound healing. In addition, HPLC analysis was also performed to estimate the active polyphenols (GTPs) present in the hydro extract of green tea leaves. ResultsWound healing was improved in diabetic skin wounds following treatment with GTE at doses of 100–200 mg/dl for three weeks. The wound parameters contraction, epithelialization, and scar formation significantly improved in a short time (14 days) compared to the longer periods identified in diabetic non-treated rats (20 days) and the standard control (15.5 days). Molecular analyses reported a significant increase in the levels of miR-21, miR-23a, and miR-146a and a decrease in the levels of miR-29b in green tea-treated diabetic rats compared to those in the standard control and STZ-diabetic non-treated rats. In addition, the molecular apoptotic genes Bax and caspase-3 significantly increased, and the BcL-2 gene significantly decreased following treatment with green tea polyphenols. ConclusionsThe data showed that active green tea polyphenols (GTPs) present in GTE significantly improved diabetic wound healing by controlling apoptotic genes and the circulating microRNAs miR-21, miR-23a, miR-146a, and miR-29b, which might be involved in cellular apoptosis and angiogenesis processes. Thus, to establish a future model for the treatment of diabetic wounds, further studies are needed to understand the potential association of these biological parameters with the wound-healing process in diabetic wounds.

Poly(oxyethylene)/Poly(oxypropylene) butyl ether prolongs the repellent effect of N,N-diethyl-3-toluamide on the skin.

N,N-diethyl-meta-toluamide (DEET) is a widely used insect repellent, with minimal skin permeation and sustained repellent activity in the superficial layers of the skin. In this study, we prepared a 10% DEET formulation consisting of 40% ethanol with or without 2% poly(oxyethylene)/poly(oxypropylene) butyl ether (POE-POP), an amphiphilic random copolymer. Further, we demonstrated the effects of POE-POP on tensile stress (stickiness), hydrophobicity, skin retention, permeation, and repellent activity of DEET. Stickiness was measured in male ICR mice (7-week old), and skin retention and permeation were evaluated in male Wistar rats (7-week old). In addition, female Aedes albopictus were used to measure the repellent action of DEET. The addition of POE-POP did not affect stickiness, volatility, and degradability but decreased logP and increased viscosity of DEET. Next, we demonstrated the behavior of DEET formulations in the rat skin. POE-POP prolonged the retention of DEET in the superficial layers of the rat skin (skin surface and stratum corneum) and decreased the penetration of DEET into rat skin tissues (epithelium and dermis). The repellent effect of DEET was also enhanced by the addition of POE-POP. However, severe skin damage was not observed after repetitive treatment with DEET formulations containing POE-POP for one month (twice a day). In conclusion, we demonstrated that a 10% DEET formulation consisting of 40% ethanol and 2% POE-POP attenuated the skin penetration and prolonged the repellent action of DEET without causing stickiness and skin damage. We conclude that the combination of ethanol and POE-POP is useful as a safe and effective delivery system for the development of insect repellent formulations containing DEET.

Viaminate Inhibits Propionibacterium Acnes-induced Abnormal Proliferation and Keratinization of HaCat Cells by Regulating the S100A8/S100A9- MAPK Cascade.

Viaminate, a vitamin A acid drug developed in China, has been clinically used in acne treatment to regulate epithelial cell differentiation and proliferation, inhibit keratinization, reduce sebum secretion, and control immunological and anti-inflammatory actions; however, the exact method by which it works is unknown. In the present study, acne was induced in the ears of rats using Propionibacterium acnes combined with sebum application. After 30 days of treatment with viaminate, the symptoms of epidermal thickening and keratin overproduction in the ears of rats were significantly improved. Transcriptomic analysis of rat skin tissues suggested that viaminate significantly regulated the biological pathways of cellular keratinization. Gene differential analysis revealed that the S100A8 and S100A9 genes were significantly downregulated after viaminate treatment. The results of qPCR and Western blotting confirmed that viaminate inhibited the expression of S100A8 and S100A9 genes and proteins in rat and HaCat cell acne models, while its downstream pathway MAPK (MAPK p38/JNK/ERK1/2) protein expression levels were suppressed. Additional administration of the S100A8 and S100A9 complex protein significantly reversed the inhibitory effect of viaminate on abnormal proliferation and keratinization levels in acne cell models. In summary, viaminate can improve acne by modulating S100A8 and S100A9 to inhibit MAPK pathway activation and inhibit keratinocyte proliferation and keratinization levels.

Altered bile acid metabolism in skin tissues in response to ionizing radiation: deoxycholic acid (DCA) as a novel treatment for radiogenic skin injury

Objective Radiogenic skin injury (RSI) is a common complication during cancer radiotherapy or accidental exposure to radiation. The aim of this study is to investigate the metabolism of bile acids (BAs) and their derivatives during RSI. Methods Rat skin tissues were irradiated by an X-ray linear accelerator. The quantification of BAs and their derivatives were performed by liquid chromatography–mass spectrometry (LC–MS)-based quantitative analysis. Key enzymes in BA biosynthesis were analyzed from single-cell RNA sequencing (scRNA-Seq) data of RSI in the human patient and animal models. The in vivo radioprotective effect of deoxycholic acid (DCA) was detected in irradiated SD rats. Results Twelve BA metabolites showed significant differences during the progression of RSI. Among them, the levels of cholic acid (CA), DCA, muricholic acid (MCA), chenodeoxycholic acid (CDCA), glycocholic acid (GCA), glycohyodeoxycholic acid (GHCA), 12-ketolithocholic acid (12-ketoLCA) and ursodeoxycholic acid (UDCA) were significantly elevated in irradiated skin, whereas lithocholic acid (LCA), tauro-β-muricholic acid (Tβ-MCA) and taurocholic acid (TCA) were significantly decreased. Additionally, the results of scRNA-Seq indicated that genes involved in 7a-hydroxylation process, the first step in BA synthesis, showed pronounced alterations in skin fibroblasts or keratinocytes. The alternative pathway of BA synthesis is more actively altered than the classical pathway after ionizing radiation. In the model of rat radiogenic skin damage, DCA promoted wound healing and attenuated epidermal hyperplasia. Conclusions Ionizing radiation modulates the metabolism of BAs. DCA is a prospective therapeutic agent for the treatment of RSI.