Burn Ointment Promotes Cutaneous Wound Healing by Modulating the PI3K/AKT/mTOR Signaling Pathway

Zuyangping formula promotes skin wound healing in diabetic rats

OBJECTIVE

To evaluate the effects of Zuyangping (, ZYP) formula on wound healing in diabetic rats, as well as the molecular mechanisms involved.

METHODS

The main compounds in ZYP formula were identified by the Liquid chromatography-tandem mass spectrometry. Sprague-Dawley rats, injected with streptozotocin (STZ) to establish diabetes model, then, formed a defective skin trauma in the back, and each group was treated with corresponding drugs once a day. Granulation was taken from each time node for histological analysis. The Western blotting was used to measured protein expression of advanced glycation end products receptor (RAGE) and hypoxia-inducible factor-1α (HIF-1α) axis-related proteins. The relative expression levels of inflammatory cytokines and growth factors were measured by the enzyme-linked immunosorbent assay method.

RESULTS

The main ingredients were identified in the ZYP formula. Histological analysis showed that the ZYP formula could inhibit the expression of inflammation, promote angiogenesis and collagen deposition. In addition, the ZYP formula could regulate the expression of RAGE and HIF1-α axis-related proteins, thus promoting the wound healing in diabetic rats.

CONCLUSION

The ZYP formula could accelerate wound healing in diabetic rats.

Topical application of anti-inflammatory agents on burn wounds and their effect on healing

Advancements in the treatment of burns have considerably improved overall survival rates, but they have also highlighted several long-term sequelae related to the injury. Hypertrophic scars can impair function, reduce quality of life, and require multiple procedures as well as physical therapy. The purpose of this study was to investigate the effects of topical application of anti-inflammatory drugs in the treatment of burns. Up to 15 deep-partial thickness burns were created on the dorsum of four anesthetized swine. Subsequently, the burn wounds were randomized to receive amiloride, celecoxib, dexamethasone or minocycline mixed in a hydrogel. Silver sulfadiazine cream and blank hydrogel acted as controls. The animals were followed for 90 days and the wounds were assessed on days 3, 7, 14, 28 and 90 post-burn. Assessments were performed using photographs (macroscopic healing, contraction), laser-speckle imaging (blood perfusion), 3D camera (scarring, pigmentation), and histology (inflammation, burn depth, epidermal maturation). Inflammation was present in all burn wound histology specimens and peaked on day 7 in all groups. Regardless of the treatment the burns progressed and were deeper on day 7 in comparison to day 3. The burns were 50 - 80 % healed by day 14, but no significant differences were observed. No differences in epidermal thickness, rete ridges, contraction, hypopigmentation, or scar elevation were seen on day 90. Topical anti-inflammatories did not significantly decrease inflammation or mitigate burn wound progression in deep partial thickness burns in pigs. Also, no significant differences in wound healing or quality of healing were observed.

Burn Wound Healing Abilities of a Uronic Acid Containing Exopolysaccharide Produced by the Marine Bacterium Halomonas malpeensis YU-PRIM-29 T

Bacterial exopolysaccharides (EPS) are an emerging class of biopolymers with extensive applications in different fields due to their versatile physico-chemical and biological properties. The role of EPS in healing of different wound types is gaining interest in the tissue engineering sector. Burn is one of the devitalizing injuries that causes greater physical harm and can be fatal. Appropriate treatment modalities have to be followed for faster healing outcomes and to minimize the risk. In this study, a bacterial EPS (EPS-H29) from the marine bacterium Halomonas malpeensis YU-PRIM-29 T was used to treat the burn wound in vivo. The biochemical and structural characterizations of EPS-H29 were carried out using standard methods. In addition, FE-SEM, conformational, rheological, and HP-GPC analyses were carried out. In vitro biocompatibility of EPS-H29 was studied in human dermal fibroblasts (HDFs) and keratinocytes (HaCaT). Scratch assay was used to study the wound healing in vitro. For in vivo evaluation, burn wound (second-degree) was created on Wistar albino rats and treated with EPS-H29 along with appropriate control groups. The total sugar and protein contents of EPS-H29 were 72.0 ± 1.4% and 4.0 ± 0.5%, respectively, with a molecular weight of 5.2 × 105 Da. The lyophilized samples exhibited porous surface features, and in solution, it showed triple helical conformation and shear thickening behavior. In vitro cell-based assays showed biocompatibility of EPS-H29 up to 200 μg/mL concentration. At a concentration up to 50 μg/mL, EPS-H29 promoted cell proliferation. Significant increase in the HDF cell migration was evident with EPS-H29 (15 μg/mL) treatment in vitro and induced significantly higher (p ≤ 0.0001) closure of the scratch area (90.3 ± 1.1%), compared to the control (84.3 ± 1.3%) at 24 h. Enhanced expression of Ki-67 was associated with the cell proliferative activities of EPS-H29. The animals treated with EPS-H29 showed improved healing of burn wounds with significantly higher wound contraction rate (80.6 ± 9.4%) compared to the positive control (54.6 ± 8.0%) and untreated group (49.2 ± 3.7%) with histopathological evidence of epidermal tissue formation at 15 days of treatment. These results demonstrate the biocompatibility and burn wound healing capability of EPS-H29 and its potential as an effective topical agent for the burn wound care.

Research on traditional Chinese medicine as an effective drug for promoting wound healing

ETHNOPHARMACOLOGICAL RELEVANCE

The incidence of skin trauma is high and the repair process is complex, often leading to poor healing and other issues, which can result in significant economic and social burdens. Traditional Chinese medicine (TCM) is a valuable resource with proven effectiveness and safety in wound repair, widely utilized in clinical practice. A systematic analysis of wound healing with a focus on TCM research progress holds both academic and clinical importance.

AIM OF THE REVIEW

This article reviews the research progress of TCM in promoting wound healing, and provides basic data for the development of innovative drugs that promote wound healing.

MATERIALS AND METHODS

This article provides a review of the literature from the past decade and conducts a thorough analysis of various databases that contain reports on the use of TCM for wound repair. The data for this systematic research was gathered from electronic databases including CNKI, SciFinder, and PubMed. The study explores and summarizes the research findings and patterns by creating relevant charts.

RESULTS

This study reviewed the mechanism of wound healing, experimental TCM methods to promote wound healing, the theory and mode of action of TCM to promote wound healing, the active ingredients of TCM that promote wound healing, the efficacy of TCM formulae to promote wound healing, and the potential toxicity of TCM and its antidotes. This study enriched the theory of TCM in promoting wound healing.

CONCLUSION

Skin wound healing is a complex process that can be influenced by various internal and external factors. This article offers a theoretical foundation for exploring and utilizing TCM resources that enhance wound repair. By analyzing a range of TCM that promote wound healing, the article highlights the clinical importance and future potential of these medicines in promoting wound healing.

Foam dressing and micropower vacuum dressing promote diabetic foot ulcer wound healing by activating the PI3K/AKT/mTOR pathway in rats

Foam dressing (FD) and micropower vacuum dressing (MVD) have been applied in the treatment of diabetic foot ulcer (DFU). However, research about the mode of action on the efficacy of the two dressings is extremely rare. This study proposed to explore the mechanism involved in diabetic wound healing under FD or MVD treatment. Macroscopical study was performed to evaluate the effectiveness of FD and MVD on wound healing in a rat model of DFU. Morphological analysis in the wound skin tissue was conducted by hematoxylin and eosin staining. Meanwhile, inflammatory cytokines in serum were measured by enzyme linked immunosorbent assay. The protein expression of phosphatidylinositol 3 kinase, protein kinase B and mammalian target of rapamycin (PI3K/AKT/mTOR) and their phosphorylation levels were determined by western blotting. We found that wound healing in rats with DFU was enhanced with the application of FD and MVD. The therapeutic efficacy of FD was superior to MVD. Compared with diabetic foot group, the concentrations of inflammatory cytokines, tumor necrosis factor alpha, interleukin-1β and interleukin-6, were significantly down-regulated. Besides, the phosphorylation levels of PI3K, AKT and mTOR were up-regulated under FD or MVD treatment. We demonstrated that the treatment of FD and MVD effectively promoted the wound skin healing through activating the PI3K/AKT/mTOR pathway. Our research may provide a new idea for exploring the mode of action of dressing application in healing of DFU.

Curative Effect and Mechanisms of Radix Arnebiae Oil on Burn Wound Healing in Rats

Radix arnebiae oil (RAO) is a clinically useful traditional Chinese medical formula with outstanding curative effects on burns. However, the mechanism of the effect of RAO on wound healing remains unclear. The present study investigates the molecular mechanisms of the potential curative effect of RAO on wound healing. The concentrations of the main constituents, shikonin, imperatorin, and ferulic acid in RAO detected by HPLC were 24.57, 3.15, and 0.13 mg/mL, respectively. A rat burn model was established, and macroscopic and histopathological studies were performed. RAO significantly accelerated wound closure and repair scarring, increased superoxide dismutase activities, and reduced malondialdehyde. RAO also downregulated interleukin (IL)-6, IL-1β and tumor necrosis factor-α in wound tissues and increased secretion of vascular endothelial growth factor, epidermal growth factor, and transforming growth factor (TGF)-β1. RAO increased the gene expression of TGF-β1, type I and III collagen, and increased the protein expression of TGF-β1 and phosphorylation of PI3K and Akt. In conclusion, RAO likely promotes wound healing via antioxidant and anti-inflammatory activities and increases re-epithelization. Activation of the TGF-β1/PI3K/Akt pathway may play an important role in the healing efficacy of RAO. These findings suggest that RAO could be a promising alternative local treatment for burn wound healing.

Ropivacaine inhibits wound healing by suppressing the proliferation and migration of keratinocytes via the PI3K/AKT/mTOR Pathway

Background

After surgery, millions of people suffer from delayed healing or wound dehiscence with subsequent severe complications, even death. Previous studies have reported that ropivacaine exhibits anti-proliferative and anti-migratory activities on numerous cells. Whether ropivacaine is able to influence the proliferation and migration of keratinocytes is still unclear. This study aimed to investigate the effect of ropivacaine on keratinocytes and its underlying molecular mechanism.

Methods

Adult male Sprague–Dawley rats were allocated to establish wound healing models with or without 0.75% ropivacaine treatment and assessed the epidermal thickness by HE staining. HaCaT cells were cultured to evaluate the effect of ropivacaine on wound healing. The cell proliferation, apoptosis status and migration were detected in vitro. Moreover, western blotting was used to examine expression to with PI3K/AKT/mTOR signaling pathways for molecular studies and the changes in inflammatory factors (IL-6, IL-10, TNF-α) were detected by ELISA.

Results

In the present study, we found that ropivacaine delayed wound closure in vivo. In vitro experiments, it was demonstrated that ropivacaine significantly inhibited the proliferation and migration of HaCaT cells via the suppression of PI3K/AKT/mTOR signaling pathway. Activation of PI3K/AKT/mTOR signaling pathway reversed the effects of ropivacaine on the proliferation and migration of HaCaT cells. Furthermore, ropivacaine contributed to the release of pro-inflammatory cytokines (IL-6 and TNF-α) and inhibited the secretion of anti-inflammatory cytokines of keratinocytes (IL-10).

Conclusions

Our research demonstrated that ropivacaine treatment showed a more decreased wound closure rate. Mechanistically, we found that ropivacaine suppressed the proliferation and migration of keratinocytes and altered the expression of cytokines by inhibiting PI3K/AKT/mTOR pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01646-0.

IL-25 improves diabetic wound healing through stimulating M2 macrophage polarization and fibroblast activation

BACKGROUND

Persistent chronic inflammation is one of the main pathogenic characteristics of diabetic wounds. The resolution of inflammation is important for wound healing and extracellular matrix (ECM) formation. Interleukin (IL)-25 can modulate the function of macrophage and fibroblast, but its role and mechanism of action in the treatment of diabetic wounds remain largely unclear.

METHODS

The mice were categorized into diabetic, diabetic + IL-25 and control groups. Human monocytic THP-1 cell line and human dermal fibroblast (HDF) were stimulated under different IL-25 conditions. Then, flow cytometry, real-time quantitative PCR (RT-qPCR), Western blot (WB), and immunofluorescence (IF) assays were carried out.

RESULTS

The mice in diabetes group (DG) had a slower wound healing rate, more severe inflammation, less blood vessels and more disordered collagen than those in control group (CG). Intradermal injection of IL-25 could improve these conditions. IL-25 promoted M2 macrophage polarization and fibroblast activation in DG and high-glucose environment. The phenomenon, which was dependent on PI3K/AKT/mTOR and TGF-β/SMAD signaling, could be blocked by LY294002 and LY2109761.

CONCLUSION

IL-25 may serve as a therapeutic target to improve wound healing in diabetic mice.

Comparative study of royal jelly, propolis, and photobiomodulation therapies in 5-fluorouracil-related oral mucositis in rats

PURPOSE

This study aimed to evaluate the effects and mechanisms of action of royal jelly (RJ) and propolis compared to photobiomodulation therapy (PBMT) in an animal model of 5-fluorouracil-related oral mucositis (OM).

METHODS

Seventy-two male Wistar rats were randomly allocated to four groups (n = 18 each): control (no treatment), PBMT (intraoral laser, 6 J/cm²), RJ, and propolis. On days 0 and 2, the animals received an injection of 5-fluorouracil (5-FU). The buccal mucosa was scratched (days 3 and 4) and the treatments were initiated on day 5. Six animals of each group were euthanized on days 8, 10, and 14. Phytochemical analysis (thin-layer chromatography, TLC) and clinical, histopathological, and immunohistochemical analysis of pS6, pAKT, and NF-κB were performed, and oxidative stress markers were also investigated.

RESULTS

TLC revealed the presence of large amounts of sucrose (Rf 0.34) in RJ and of flavonoids in propolis. Lower clinical OM scores were observed on day 8, and improved morphological data were observed on day 10 in the PBMT, RJ, and propolis groups (p < 0.05). On day 8, immunoexpression of pS6, pAKT, and NF-κB was increased compared to control. On day 14, reduced glutathione (GSH) antioxidant levels were increased in the propolis group compared to control (p < 0.05).

CONCLUSIONS

Our results showed that RJ and propolis, as well as PBMT, are effective in the treatment of OM. Considering that some patients who develop OM do not have access to PBMT, the present study demonstrated that topical application of RJ and propolis may be an important alternative for the treatment of OM.