Protection of burn-induced skin injuries by the flavonoid kaempferol

Two Novel Membranes Based on Collagen and Polyphenols for Enhanced Wound Healing

Two novel membranes based on collagen and two polyphenols, taxifolin pentaglutarate (TfG5) and a conjugate of taxifolin with glyoxylic acid (DfTf), were prepared. Fourier transform infrared spectroscopy examination confirmed the preservation of the triple helical structure of collagen. A scanning electron microscopy study showed that both materials had a porous structure. The incorporation of DfTf into the freeze-dried collagen matrix increased the aggregation of collagen fibers to a higher extent than the incorporation of TfG5, resulting in a more compact structure of the material containing DfTf. It was found that NIH/3T3 mouse fibroblasts were attached to, and relatively evenly spread out on, the surface of both newly obtained membranes. In addition, it was shown that the membranes enhanced skin wound healing in rats with a chemical burn induced by acetic acid. The treatment with the materials led to a faster reepithelization and granulation tissue formation compared with the use of other agents (collagen without polyphenols and buffer saline). It was also found that, in the wound tissue, the level of thiobarbituric acid reactive substances (TBARS) was significantly higher and the level of low-molecular-weight SH-containing compounds (RSH) was significantly lower than those in healthy skin, indicating a rise in oxidative stress at the site of injury. The treatment with collagen membranes containing polyphenols significantly decreased the TBARS level and increased the RSH level, suggesting the antioxidant/anti-inflammatory effect of the materials. The membrane containing TfG5 was more effective than other ones (the collagen membrane containing DfTf and collagen without polyphenols). On the whole, the data obtained indicate that collagen materials containing DfTf and TfG5 have potential as powerful therapeutic agents for the treatment of burn wounds.

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

Cassia alata and Its Phytochemicals: A Promising Natural Strategy in Wound Recovery

Cassia alata, a traditional herb with a global presence, is renowned for its anti-inflammatory, antibacterial, and antifungal properties, making it a go-to remedy for skin ailments. While it has demonstrated wound healing capabilities in both in vitro and in vivo studies, the precise mechanisms remain elusive. This review aims to highlight its key phytochemicals, their effects, and the mechanism of action. The compounds that have been reviewed and discussed include kaempferol, apigenin, quercetin, rhein, and rutin. These polyphenols play important roles in normal and impaired wound healing processes, encompassing hemostasis, inflammation, proliferation, and tissue remodeling.

Kinetics of Inflammatory Mediators in the Immune Response to Burn Injury: Systematic Review and Meta-Analysis of Animal Studies

Burns are often accompanied by a dysfunctional immune response, which can lead to systemic inflammation, shock, and excessive scarring. The objective of this study was to provide insight into inflammatory pathways associated with burn-related complications. Because detailed information on the various inflammatory mediators is scattered over individual studies, we systematically reviewed animal experimental data for all reported inflammatory mediators. Meta-analyses of 352 studies revealed a strong increase in cytokines, chemokines, and growth factors, particularly 19 mediators in blood and 12 in burn tissue. Temporal kinetics showed long-lasting surges of proinflammatory cytokines in blood and burn tissue. Significant time-dependent effects were seen for IL-1β, IL-6, TGF-β1, and CCL2. The response of anti-inflammatory mediators was limited. Burn technique had a profound impact on systemic response levels. Large burn size and scalds further increased systemic, but not local inflammation. Animal characteristics greatly affected inflammation, for example, IL-1β, IL-6, and TNF-α levels were highest in young, male rats. Time-dependent effects and dissimilarities in response demonstrate the importance of appropriate study design. Collectively, this review presents a general overview of the burn-induced immune response exposing inflammatory pathways that could be targeted through immunotherapy for burn patients and provides guidance for experimental set-ups to advance burn research.

Why traditional herbal medicine promotes wound healing: Research from immune response, wound microbiome to controlled delivery

Impaired wound healing in chronic wounds has been a significant challenge for clinicians and researchers for decades. Traditional herbal medicine (THM) has a long history of promoting wound healing, making them culturally accepted and trusted by a great number of people in the world. However, for a long time, the understanding of herbal medicine has been limited and incomplete, particularly in the allopathic medicine-dominated research system. The therapeutic effects of individual components isolated from THM are found less pronounced compared to synthetic chemical medicine, and the clinical efficacy is always inferior to herbs. In the present article, we review and discuss underlying mechanisms of the skin microbiome involved in the wound healing process; THM in regulating immune responses and commensal microbiome. We additionally propose few pioneer ideas and studies in the development of therapeutic strategies for controlled delivery of herbal medicine. This review aims to promote wound care with a focus on wound microbiome, immune response, and topical drug delivery systems. Finally, future development trends, challenges, and research directions are discussed.

Elucidating the potential pharmaceutical mechanism of Gyejibokryeong-hwan on rosacea using network analysis

Rosacea is a chronic erythematous disease with telangiectasia that affects the central area of the face. However, because of the ambiguity in the pathophysiology of rosacea, its treatment has not been clearly elucidated; therefore, new therapeutic options need to be developed. Gyejibokryeong-hwan (GBH) is widely used in clinical practice for various blood circulation disorders, including hot flushes. Therefore, we explored the potential pharmaceutical mechanism of GBH on rosacea and investigated the therapeutic points exclusive to GBH through comparative analysis with chemical drugs recommended in 4 guidelines for rosacea based on network analysis. The active compounds in GBH were identified, and the proteins targeted by these compounds and the genes related to rosacea were searched. Additionally, the proteins targeted by the guideline drugs were also searched to compare their effects. And the pathway/term analysis of common genes was conducted. Ten active compounds were obtained for rosacea. There were 14 rosacea-related genes targeted by GBH, with VEGFA, TNF, and IL-4, which were suggested as core genes. The pathway/term analysis of the 14 common genes revealed that GBH could potentially act on rosacea via 2 pathways: the "interleukin 17 signaling pathway" and the "neuroinflammatory response." Comparison and analysis of the protein targets between GBH and guideline drugs revealed that only GBH separately acts on the "vascular wound healing pathway." GBH has the potential to act on IL-17 signaling pathway, neuroinflammatory response and vascular wound healing pathway. Further studies are needed to determine the potential mechanism of GBH in rosacea.

Peripheral blood neutrophil-to-lymphocyte ratio in inflammatory bowel disease and disease activity: A meta-analysis

OBJECTIVE

The peripheral blood neutrophil-to-lymphocyte ratio (NLR) is a valuable predictor of clinical disease activity in inflammatory bowel disease (IBD). Therefore, we conducted a meta-analysis to evaluate the clinical significance of peripheral blood NLR in IBD patients.

METHODS

A comprehensive literature search was conducted by searching PubMed, Embase, Web of Science, Cochrane Library, and Chinese databases from inception to May 10, 2021. We used the standard mean difference (SMD) with a 95% confidence interval (CI) to estimate the pooled effect and subgroup analysis to investigate heterogeneity.

RESULTS

Sixteen studies including 2185 IBD patients and 993 healthy controls (HCs) were enrolled in this study. The peripheral blood NLR values were significantly higher in 1,092 IBD patients than in 933 HCs (SMD = 1.54, 95% CI = 1.05-2.02, P < 0.001) and in 1,269 patients with active IBD than in 1,056 patients with remissive IBD (SMD = 1.55, 95% CI = 1.06-2.05, P < 0.001). Subgroup analysis of the major subtypes of IBD revealed significantly elevated peripheral blood NLR values in patients with active ulcerative colitis (UC) compared to HCs (SMD = 2.04), remissive UC than HCs (SMD = 0.63), and active UC than in those with remissive UC (SMD = 1.32) (P < 0.05). Both Crohn's disease (CD) patients and active CD patients had significantly elevated peripheral blood NLR values than HCs with the SMD of 0.52 and 3.53 (P < 0.001).

CONCLUSIONS

Peripheral blood NLR could serve as a valuable biomarker for predicting disease severity in IBD patients.

Umbilical cord-derived mesenchymal stem cells preconditioned with isorhamnetin: potential therapy for burn wounds

BACKGROUND

Impaired wound healing can be associated with different pathological states. Burn wounds are the most common and detrimental injuries and remain a major health issue worldwide. Mesenchymal stem cells (MSCs) possess the ability to regenerate tissues by secreting factors involved in promoting cell migration, proliferation and differentiation, while suppressing immune reactions. Preconditioning of MSCs with small molecules having cytoprotective properties can enhance the potential of these cells for their use in cell-based therapeutics.

AIM

To enhance the therapeutic potential of MSCs by preconditioning them with isorhamnetin for second degree burn wounds in rats.

METHODS

Human umbilical cord MSCs (hU-MSCs) were isolated and characterized by surface markers, CD105, vimentin and CD90. For preconditioning, hU-MSCs were treated with isorhamnetin after selection of the optimized concentration (5 µmol/L) by cytotoxicity analysis. The migration potential of these MSCs was analyzed by the in vitro scratch assay. The healing potential of normal, and preconditioned hU-MSCs was compared by transplanting these MSCs in a rat model of a second degree burn wound. Normal, and preconditioned MSCs (IH + MSCs) were transplanted after 72 h of burn injury and observed for 2 wk. Histological and gene expression analyses were performed on day 7 and 14 after cell transplantation to determine complete wound healing.

RESULTS

The scratch assay analysis showed a significant reduction in the scratch area in the case of IH + MSCs compared to the normal untreated MSCs at 24 h, while complete closure of the scratch area was observed at 48 h. Histological analysis showed reduced inflammation, completely remodeled epidermis and dermis without scar formation and regeneration of hair follicles in the group that received IH + MSCs. Gene expression analysis was time dependent and more pronounced in the case of IH + MSCs. Interleukin (IL)-1β, IL-6 and Bcl-2 associated X genes showed significant downregulation, while transforming growth factor β, vascular endothelial growth factor, Bcl-2 and matrix metallopeptidase 9 showed significant upregulation compared to the burn wound, showing increased angiogenesis and reduced inflammation and apoptosis.

CONCLUSION

Preconditioning of hU-MSCs with isorhamnetin decreases wound progression by reducing inflammation, and improving tissue architecture and wound healing. The study outcome is expected to lead to an improved cell-based therapeutic approach for burn wounds.

Sorocea guilleminiana Gaudich.: Wound healing activity, action mechanisms, and chemical characterization of the leaf infusion

ETHNOPHARMACOLOGICAL RELEVANCE

Sorocea guilleminina Gaudich. is a tree or shrub endemic to Brazil. Its leaves are used in Brazilian folk medicine for the healing of wounds, stomach problems, inflammation and as diuretic. The present study evaluates the activity and action mechanisms of the healing properties of the aqueous extract of S. guilleminiana leaves (AESg), in experimental models in vivo and in vitro, as well as performs a phytochemical analysis of the extract.

MATERIALS AND METHODS

The AESg was prepared by infusion: Ten g of dry leaves powder in 1 L hot water, soaked for 15 min, filtered, lyophilized, and stored at -30 °C. Phytochemical analyses were realized by colorimetry and HPLC/ESI/MS. Its' in vitro cytotoxicity was evaluated on fibroblastic N3T3 cells. The potential of the wound healing activity in vivo was evaluated using excision and incision wound rat models, by histopathology of the injured skin along with the determination of nitric oxide, cytokines (IL-1β, IL-10, and TNF-α), and antioxidant parameters (GSH, MPO and CAT). In vitro wound healing activity was also demonstrated in scratched N3T3 cells, by measuring the proliferation/migration rate.

RESULTS

The phytochemical analysis of the AESg revealed a strong presence of polar compounds, especially flavonoids (4 majoritarian), as well as terpenes and/or sterols (2 majoritarian). The AESg showed no toxicity in the N3T3 cell line (IC₅₀ > 800 μg/mL). Topical treatment with the AESg showed an increase (p < 0.05) in wound contraction with 2 mg/g cream on days 5 and 9 (43.56% and 6.70% increase, respectively), and with 50 mg/g on days 7 and 9 (10.88% and 7.91%, respectively), compared to the vehicle (non-ionic neutral cream). Topical application of AESg (2 or 50 mg/g non-ionic cream) in incised wounds caused an increase in the force necessary for the rupture of the wound when compared to the vehicle group. No changes in cytokines (IL-1β, IL-10, or TNF-α) or NO accumulation was found with up to 50 mg/g AESg treatment. For antioxidant activity on the incision wound, an increase in GSH levels was denoted with the AESg use, at the lowest and highest dose (2 and 50 mg/g) by 75.86% and 61.20% respectively, when compared to the vehicle. Also, the CAT activity was accentuated by AESg at the highest dose (50 mg/g) by 85.87%. Finally, the AESg at all doses attenuated MPO activity significantly in the incision wound by 71.35%, 73.21%, 78.08%, respectively. In the scratch test on N3T3 cells, the treatment with AESg resulted also in an increase in fibroblast proliferation/migration rate, compared to the vehicle.

CONCLUSION

AESg is not cytotoxic. The results confirm the popular use of the leaf infusion of S. guilleminiana for the treatment of cutaneous wounds, possibly by stimulating the proliferation of fibroblasts with a consequent deposition of collagen, fastening rearrangement of collagen fibers, and greater transformation into myofibroblasts, essential in the healing process. Preliminary chemical analyzes of AESg revealed the presence mainly of phenolic compounds, being salicylic acid, gallic acid, pinocembrin and isoquercitrin the majoritarian ones.

Development and formulation of Moringa oleifera standardised leaf extract film dressing for wound healing application

ETHNOPHARMACOLOGICAL RELEVANCE

M.oleifera is a medicinal plant traditionally used for skin sores, sore throat and eye infections. Recently, the wound healing property of the leaves of M. oleifera was has been well demonstrated experimentally in both in vivo and in vitro models. However, there is a lack of research which focuses on formulating M.oleifera into a functional wound dressing. In this study, the M.oleifera leaf standardized aqueous extract with highest potency in vitro migration was formulated into a film for wound healing application.

MATERIALS AND METHODS

Firstly, M. oleifera leaf were extracted in various solvents (aqueous, 50%, 70% and 100% ethanolic extracts) and standardized by reference standards using UHPLC technique. The extracts were then tested for cell migration and proliferation using HDF and HEK cell lines. M. oleifera leaf aqueous extract was then incorporated into alginate-pectin (SA-PC) based film dressing. The film dressings were characterized for the physicochemical properties and the bioactives release from the M. oleifera leaf extract loaded film dressing was also investigated using Franz diffusion cells.

RESULTS

All extracts were found to contain vicenin-2, chlorogenic acid, gallic acid, quercetin, kaempferol, rosmarinic acid and rutin. Among all M. oleifera extracts, aqueous standardized leaf extracts showed the highest human dermal fibroblast and human keratinocytes cells proliferation and migration properties. Among the film formulations, SA-PC (3% w/v) composite film dressing containing M. oleifera aqueous leaf extract was found to possess optimal physicochemical properties as wound dressing.

CONCLUSION

A potentially applicable wound dressing formulated as an alginate-pectin film containing aqueous extracts of M. oleifera has been developed. The dressing would be suitable for wounds with moderate exudates.

Activity of Porophyllum ruderale leaf extract and 670-nm InGaP laser during burns repair in rats

BACKGROUND

In this study, we investigated the effects of an extract of the leaves of Porophyllum ruderale and laser irradiation on the healing of burns.

METHODS

Seventy-two rats were divided in four groups: untreated controls, treated with laser irradiation, treated with P. ruderale and treated with both P. ruderale and laser irradiation. Burns were produced with a metal plate on the backs of the animals. Wound samples were collected for structural and morphometric analyses and to quantify the expression of TGF-β1 and VEGF.

RESULTS

Laser irradiation increased the number of fibroblasts, collagen fibers and newly formed vessels and decreased the number of granulocytes at the site of the wounds. Densitometric analysis revealed a significant increase in the expression of TGFβ-1 in the wounds treated with laser irradiation and with the P. ruderale extract at the beginning of the healing process and a decreased during the experimental period. The expression of VEGF was highlighted in the lesions irradiated with laser alone.

CONCLUSION

Inspite of not showing a beneficial effect on the laser combination with the P. ruderale extract, when the laser was used separately, a positive effects to enhance the healing of second-degree burns was promoted. P. ruderale was effective in decreasing the granulocytes during the repair process indicating a possible anti-inflammatory action of this extract of native flora, widely used in folk medicine, but little studied experimentally.

The effect of submicron emulsion systems on transdermal delivery of kaempferol

In this study, submicron emulsions have been employed as a carrier for the topical application of kaempferol. The effect of components of submicron emulsions on the physicochemical properties and permeation capability of drug were evaluated. In case of drug-loaded submicron emulsions, the cumulative amount over 12 h (Q(12 h)), lag time and deposition in skin amount ranged from 13.0±3.4 to 236.1±21.2 µg/cm(2), 1.7 to 5.3 h, and 1.10 to 7.76 µg/cm(2), respectively, which indicated that the permeation parameters of kaempferol were markedly influenced by the component ratio. Kaempferol dispensed in isopropyl myristate was used as the control. The Q(12 h), lag time and deposition amount in skin were 4.2±1.8 µg/cm(2), 6.0 h and 2.25±0.60 µg/cm(2), respectively. The data showed that used appropriate submicron emulsions as vehicle could significantly increase the Q(12 h) and deposition amount in skin and shorten the lag time, demonstrating that submicron emulsions have a potent enhancement effect for kaempferol transdermal delivery.

Anti-inflammatory effects of spermidine in lipopolysaccharide-stimulated BV2 microglial cells

Background

Spermidine, a naturally occurring polyamine, displays a wide variety of internal biological activities including cell growth and proliferation. However, the molecular mechanisms responsible for its anti-inflammatory activity have not yet been elucidated.

Methods

The anti-inflammatory properties of spermidine were studied using lipopolysaccharide (LPS)-stimulated murine BV2 microglia model. As inflammatory parameters, the production of nitric oxide (NO), prostaglandin E₂ (PGE₂), interleukin (IL)-6 and tumor necrosis factor (TNF)-α were evaluated. We also examined the spermidine's effect on the activity of nuclear factor-kappaB (NF-κB), and the phosphoinositide 3-kinase (PI3K)/Akt and mitogen-activated protein kinases (MAPKs) pathways.

Results

Pretreatment with spermidine prior to LPS treatment significantly inhibited excessive production of NO and PGE₂ in a dose-dependent manner, and was associated with down-regulation of expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Spermidine treatment also attenuated the production of pro-inflammatory cytokines, including IL-6 and TNF-α, by suppressing their mRNA expressions. The mechanism underlying spermidine-mediated attenuation of inflammation in BV2 cells appeared to involve the suppression of translocation of NF-κB p65 subunit into the nucleus, and the phosphorylation of Akt and MAPKs.

Conclusions

The results indicate that spermidine appears to inhibit inflammation stimulated by LPS by blocking the NF-κB, PI3K/Akt and MAPKs signaling pathways in microglia.

Whey protein enhances normal inflammatory responses during cutaneous wound healing in diabetic rats

Background

Prolonged wound healing is a complication of diabetes that contributes to mortality. Impaired wound healing occurs as a consequence of excessive reactive oxygen species (ROS) production. Whey protein (WP) is able to reduce the oxygen radicals and increase the levels of the antioxidant glutathione. Thus, the aim of this study was to determine whether dietary supplementation with WP could enhance normal inflammatory responses during wound healing in diabetic rats. Animals were assigned into a wounded control group (WN), a wounded diabetic group (WD) and a wounded diabetic group orally supplemented with whey protein (WDWP) at a dose of 100 mg/kg body weight.

Results

Whey protein was found to significantly decrease the levels of malondialdehyde (MDA), nitric oxide (NO) and ROS. A significant restoration of the glutathione level was observed in WDWP rats. During the early wound healing stage, IL-1β, TNF-α, IL-6, IL-4 and neutrophil infiltration were significantly decreased in WD mice. WP supplementation was found to restore the levels of these inflammatory markers to the levels observed in control animals. In addition, the time required for wound healing was significantly prolonged in diabetic rats. WP was found to significantly decrease the time required for wound healing in WDWP rats.

Conclusion

In conclusion, dietary supplementation with WP enhances the normal inflammatory responses during wound healing in diabetic mice by restoring the levels of oxidative stress and inflammatory cytokines.

Anti-inflammatory effects of Polygala tenuifolia root through inhibition of NF-κB activation in lipopolysaccharide-induced BV2 microglial cells

ETHNOPHARMACOLOGICAL RELEVANCE

The root of Polygala tenuifolia Willd is a well-known traditional Oriental medicine and has been prescribed for treatment of dysfunction in memorial systems and various brain inflammatory diseases. The present study was designed to validate the anti-inflammatory effects of the water extract of Polygala tenuifolia root (WEPT).

MATERIALS AND METHODS

The anti-inflammatory properties of WEPT were studied using lipopolysaccharide (LPS)-stimulated murine BV2 microglia model. As inflammatory parameters, the production of nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase (COX)-2, prostaglandin E(2) (PGE(2)), tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were evaluated. We also examined the extract's effect on the activity of nuclear factor-kappaB (NF-κB), and toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (Myd-88) expression.

RESULTS

WEPT suppressed LPS-induced production of NO, PGE(2), and expression of iNOS and COX-2 in a dose-dependent manner, without causing cytotoxicity. It also significantly reduced generation of proinflammatory cytokines, including IL-1β and TNF-α. In addition, WEPT suppressed NF-κB translocation by blockade of IkappaB-α (IκB-α) degradation and inhibited TLR4 and Myd-88 expression in LPS-stimulated BV2 cells.

CONCLUSIONS

These results indicate that the inhibitory effects of WEPT on LPS-stimulated inflammatory mediator production in BV2 microglia are associated with suppression of the NF-κB and toll-like receptor signaling pathways. Therefore, Polygala tenuifolia extracts may be useful in treatment of neurodegenerative diseases by inhibition of inflammatory mediator production in activated microglia.