Topical administration of pterostilbene accelerates burn wound healing in diabetes through activation of the HIF1α signaling pathway

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.

Multifunctional nanocomposites mediated novel hydrogel for diabetic wound repair

The regeneration and repair of diabetic wounds, especially those including bacterial infection, have always been difficult and challenging using current treatment. Herein, an effective strategy is reported for constructing glucose-responsive functional hydrogels using nanocomposites as nodes. In fact, tannic acid (TA)-modified ceria nanocomposites (CNPs) and a zinc metal-organic framework (ZIF-8) were employed as nodes. Subsequent crosslinking with 3-acrylamidophenylboronic acid achieved functional nanocomposite-hydrogels (TA@CN gel, TA@ZMG gel) by radical-mediated polymerization. Compared with a simple physically mixed hydrogel system, the mechanical properties of TA@CN gel and TA@ZMG gel are significantly enhanced due to the intervention of the nanocomposite nodes. In addition, this kind of nanocomposite hydrogel can realize the programmed loading of drugs and release of drugs in response to glucose/PH, to coordinate and promote its application in the regeneration and repair of diabetic wounds and infected diabetic wounds. Specifically, TA@CN gel can remove reactive oxygen species and generate oxygen through its various enzymatic activities. At the same time, it can effectively promote neovascularization, thus promoting the regeneration and repair of diabetic wounds. Furthermore, glucose oxidase-loaded TA@ZMG gel exhibits glucose response and pH-regulating functions, triggering programmed metformin (Met) release by degrading the metal-organic framework (MOF) backbone. It also exhibited additional synergistic effects of antibacterial activity, hair regeneration and systemic blood glucose regulation, which make it suitable for the repair of more complex infected diabetic wounds. Overall, this novel nanocomposite-mediated hydrogel holds great potential as a biomaterial for the healing of chronic diabetic wounds, opening up new avenues for further biomedical applications.

Pterostilbene accelerates wound healing response in diabetic mice through Nrf2 regulation

Pterostilbene (PTS), known for its diverse beneficial effects via Nuclear factor erythroid-2 related factor (Nrf2) activation, holds potential for Diabetic Foot Ulcer (DFU) treatment. However, PTS-mediated Nrf2 regulation in diabetic wounds has yet to be elucidated. We used IC21 macrophage-conditioned media to simulate complex events that can influence the fibroblast phenotype using L929 cells during the wound healing process under a hyperglycemic microenvironment. We found that PTS attenuated fibroblast migration and alpha-smooth muscle actin (α-SMA) levels and hypoxia-inducible factor- 1 alpha (HIF1α). Furthermore, we demonstrated that wounds in diabetic mice characterized by impaired wound closure in a heightened inflammatory milieu, such as the NOD-like receptor P3 (NLRP3) and intercellular adhesion molecule 1 (ICAM1), and deficient Nrf2 response accompanying lowered Akt signaling and heme oxygenase1 (HO1) expression along with the impaired macrophage M2 marker CD206 expression, was rescued by administration of PTS. Such an elicited response was also compared favorably with the standard treatment using Regranex, a commercially available topical formulation for treating DFUs. Our findings suggest that PTS regulates Nrf2 in diabetic wounds, triggering a pro-wound healing response mediated by macrophages. This insight holds the potential for developing targeted therapies to heal chronic wounds, including DFUs.

Unlocking the therapeutic potential of natural stilbene: Exploring pterostilbene as a powerful ally against aging and cognitive decline

The therapeutic potential of natural stilbenes, with a particular focus on pterostilbene (PTE), has emerged as a promising avenue of research targeting age-associated conditions encompassing cardiovascular diseases (CVD), diabetes mellitus (DM), and cognitive decline. This comprehensive investigation delves into the intricate mechanisms through which PTE, a polyphenolic compound abundant in grapes and blueberries, exerts its advantageous effects as an anti-aging agent. Central to its action is the modulation of hallmark aging processes, including oxidative damage, inflammatory responses, telomere attrition, and cellular senescence. PTE's ability to effectively penetrate the blood-brain barrier amplifies its potential for safeguarding neural health, thereby facilitating the regulation of neuronal signalling cascades, synaptic plasticity, and mitochondrial functionality. Through engagement with sirtuin proteins, it orchestrates cellular resilience, longevity, and metabolic equilibrium. Encouraging findings from preclinical studies portray PTE as a robust candidate for counteracting age-linked cognitive decline, augmenting memory consolidation, and potentially ameliorating neurodegenerative maladies such as Alzheimer's disease (AD). The synthesis of current scientific insights accentuates the promising translational prospects of PTE as a potent, naturally derived therapeutic agent against cognitive impairments associated with aging. Consequently, these collective findings lay a solid groundwork for forthcoming clinical inquiries and innovative therapeutic interventions in this realm.

Natural Polymeric Hydrogels Encapsulating Small Molecules for Diabetic Wound Healing

Diabetes is a condition correlated with a high number of diagnosed chronic wounds as a result of a complex pathophysiological mechanism. Diabetic chronic wounds are characterized by disorganized and longer stages, compared to normal wound healing. Natural polymer hydrogels can act as good wound dressings due to their versatile physicochemical properties, represented mainly by high water content and good biocompatibility. Natural bioactive hydrogels are polymers loaded with bioactive compounds providing antibacterial and antioxidant properties, modulation of inflammation and adherence to wounded tissue, compared to traditional dressings, which enables promising future applications for diabetic wound healing. Natural bioactive compounds, such as polyphenols, polysaccharides and proteins have great advantages in promoting chronic wound healing in diabetes due to their antioxidant, anti-inflammatory, antimicrobial, anti-allergic and wound healing properties. The present paper aims to review the wound healing mechanisms underlining the main issues of chronic wounds and those specifically occurring in diabetes. Also, the review highlights the recent state of the art related to the effect of hydrogels enriched with natural bioactive compounds developed as biocompatible functional materials for improving diabetic-related chronic wound healing and providing novel therapeutic strategies that could prevent limb amputation and increase the quality of life in diabetic patients.

MicroRNA-27b Impairs Nrf2-Mediated Angiogenesis in the Progression of Diabetic Foot Ulcer

Nuclear factor erythroid-2-related factor 2 (Nrf2) is a stress-activated transcription factor regulating antioxidant genes, and a deficiency thereof, slowing lymphangiogenesis, has been reported in diabetic foot ulcer (DFU). The mode of Nrf2 regulation in DFU has been less explored. Emerging studies on miRNA-mediated target regulation show miRNA to be the leading player in the pathogenesis of the disease. In the present study, we demonstrated the role of miR-27b in regulating Nrf2-mediated angiogenesis in DFU. A lower expression of mRNA targets, such as Nrf2, HO-1, SDF-1α, and VEGF, was observed in tissue biopsied from chronic DFU subjects, which was in line with miR-27b, signifying a positive correlation with Nrf2. Similarly, we found significantly reduced expression of miR-27b and target mRNAs Nrf2, HO-1, SDF-1α, and VEGF in endothelial cells under a hyperglycemic microenvironment (HGM). To confirm the association of miR-27b on regulating Nrf2-mediated angiogenesis, we inhibited its expression through RNA interference-mediated knockdown and observed disturbances in angiogenic signaling with reduced endothelial cell migration. In addition, to explore the role of miR-27b and angiogenesis in the activation of Nrf2, we pretreated the endothelial cells with two well-known pharmacological compounds-pterostilbene and resveratrol. We observed that activation of Nrf2 through these compounds ameliorates impaired angiogenesis on HGM-induced endothelial cells. This study suggests a positive role of miR-27b in regulating Nrf2, which seems to be decreased in DFU and improves on treatment with pterostilbene and resveratrol.

PGS/Gelatin Nanocomposite Electrospun Wound Dressing

Infectious diabetic wounds can result in severe injuries or even death. Biocompatible wound dressings offer one of the best ways to treat these wounds, but creating a dressing with a suitable hydrophilicity and biodegradation rate can be challenging. To address this issue, we used the electrospinning method to create a wound dressing composed of poly(glycerol sebacate) (PGS) and gelatin (Gel). We dissolved the PGS and Gel in acetic acid (75 v/v%) and added EDC/NHS solution as a crosslinking agent. Our measurements revealed that the scaffolds' fiber diameter ranged from 180.2 to 370.6 nm, and all the scaffolds had porosity percentages above 70%, making them suitable for wound healing applications. Additionally, we observed a significant decrease (p < 0.05) in the contact angle from 110.8° ± 4.3° for PGS to 54.9° ± 2.1° for PGS/Gel scaffolds, indicating an improvement in hydrophilicity of the blend scaffold. Furthermore, our cell viability evaluations demonstrated a significant increase (p < 0.05) in cultured cell growth and proliferation on the scaffolds during the culture time. Our findings suggest that the PGS/Gel scaffold has potential for wound healing applications.

Pterostilbene loaded poly(vinyl alcohol)-gelatin cryogels as potential bioactive wound dressing material

Cryogels are support materials which are good at mimicking extracellular matrix due to their excellent hydrophilicity, biocompatibility, and macroporous structure, thus they are useful in facilitating cell activities during healing process. In this study, polyvinyl alcohol-gelatin (PVA-Gel) based cryogel membranes loaded with pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene; PTS) (PVA-Gel/PTS) was synthesized as wound dressing materials. PVA-Gel and PVA-Gel/PTS were synthesized with the polymerization yields of 96% ± 0.23% and 98% ± 0.18%, respectively, and characterized by swelling tests, Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) analysis. The swelling ratios were calculated as 98.6% ± 4.93% and 102% ± 5.1%, macroporosities were determined as 85% ± 2.13% and 88% ± 2.2%, for PVA-Gel and PVA-Gel/PTS, respectively. It was determined that PVA-Gel and PVA-Gel/PTS have 17 m² /g ± 0.76 m² /g and 20 m² /g ± 0.92 m² /g surface areas, respectively. SEM studies were demonstrated that they have ~100 μm pore sizes. According to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), trypan blue exclusion and live-dead assay results, it was observed that cell proliferation, cell number and cell viability were higher in PVA-Gel/PTS cryogel at 24, 48, and 72 h compared to PVA-Gel. A strong and transparent fluorescent light intensity was observed indicating higher cell population in PVA-Gel/PTS in comparison with PVA-Gel, according to 4',6-diamidino-2-phenylindole (DAPI) staining. SEM, F-Actin, Giemsa staining and inverted-phase microscope image of fibroblasts in PVA-Gel/PTS cryogels revealed that dense fibroblast proliferation and spindle-shaped morphology of cells were preserved. Moreover, DNA agarose gel data demonstrated that PVA-Gel/PTS cryogels had no effect on DNA integrity. Consequently, produced PVA-Gel/PTS cryogel can be used as wound dressing material to promote wound therapies, inducing cell viability and proliferation.

Nanoemulsions of Clove Oil Stabilized with Chitosan Oleate-Antioxidant and Wound-Healing Activity

Clove oil (CO) is a powerful antioxidant essential oil (EO) with anti-inflammatory, anesthetic, and anti-infective properties. It can be therefore considered a good candidate for wound-healing applications, especially for chronic or diabetic wounds or burns, where the balance of reactive oxygen species (ROS) production and detoxification is altered. However, EOs require suitable formulations to be efficiently administered in moist wound environments. Chitosan hydrophobically modified by an ionic interaction with oleic acid (chitosan oleate, CSO) was used in the present work to stabilize CO nanoemulsions (NEs). The dimensions of the NE were maintained at around 300 nm as the volume distribution for up to six months, and the CO content did not decrease to under 80% over 4 months, confirming the good stabilizing properties of CSO. The antioxidant properties of the CO NE were evaluated in vitro by a 2,2-diphenil-2-picrylhydrazyl hydrate (DPPH) assay, and in fibroblast cell lines by electron paramagnetic resonance (EPR) using α-phenyl-N-tert-butyl nitrone (PBN) as a spin trap; a protective effect was obtained comparable to that obtained with α-tocopherol treatment. In a murine burn model, the ability of CO formulations to favor macroscopic wound closure was evidenced, and a histological analysis revealed a positive effect of the CO NE on the reparation of the lesion after 18 days. Samples of wounds at 7 days were subjected to a histological analysis and parallel dosage of lipid peroxidation by means of a thiobarbituric acid-reactive substances (TBARS) assay, confirming the antioxidant and anti-inflammatory activity of the CO NE.

New Insights into Dietary Pterostilbene: Sources, Metabolism, and Health Promotion Effects

Pterostilbene (PTS), a compound most abundantly found in blueberries, is a natural analog of resveratrol. Several plant species, such as peanuts and grapes, produce PTS. While resveratrol has been extensively studied for its antioxidant properties, recent evidence also points out the diverse therapeutic potential of PTS. Several studies have identified the robust pharmacodynamic features of PTS, including better intestinal absorption and elevated hepatic stability than resveratrol. Indeed, due to its higher bioavailability paired with reduced toxicity compared to other stilbenes, PTS has become an attractive drug candidate for the treatment of several disease conditions, including diabetes, cancer, cardiovascular disease, neurodegenerative disorders, and aging. This review article provides an extensive summary of the nutraceutical potential of PTS in various disease conditions while discussing the crucial mechanistic pathways implicated. In particular, we share insights from our studies about the Nrf2-mediated effect of PTS in diabetes and associated complications. Moreover, we elucidate the important sources of PTS and discuss in detail its pharmacokinetics and the range of formulations and routes of administration used across experimental studies and human clinical trials. Furthermore, this review also summarizes the strategies successfully used to improve dietary availability and the bio-accessibility of PTS.