Pharmaceutical, clinical, and immunohistochemical studies of metformin hydrochloride topical hydrogel for wound healing application

Metformin-loaded bioinspired mesoporous silica nanoparticles for targeted melanoma therapy: Nanotopographical design with in vitro and in vivo evaluation

Bioinspired nanotopographical carriers have emerged as innovative cancer therapy strategies, mimicking natural processes to enhance targeted delivery and reduce systemic toxicity. This study presents the development of virus-like mesoporous silica nanoparticles (MSN) as a delivery platform for repurposed metformin (MTF) in a topical multi-stimuli responsive system for melanoma treatment. Metformin-loaded virus-like MSN (MTF-MSN) were fabricated and incorporated into a thermo-responsive gelling system. The particles were evaluated for morphology, zeta potential (ZP), particle size (PS), entrapment efficiency (EE%), Fourier-transform infrared (FT-IR) spectroscopy, MTT cytotoxicity assay, in vitro release, and in a melanoma in vivo model. The particles exhibited a spherical morphology, a zeta potential of +31.9 ± 1.45 mV, and a particle size of 197 ± 3.47 nm, ideal for skin penetration. MTF-MSN demonstrated significant antiproliferative activity against melanoma A375 cells, with lower IC50 values (192 μg/mL) compared to free MTF (>300 μg/mL). Sustained, pH-sensitive MTF release was observed over 48 h at pH 7.4 and 6 h at pH 5.5. In vivo studies showed enhanced anti-cancer efficacy of MTF-MSN, evidenced by elevated caspase-3 and Neurofibromin Type-1 (NF-1) levels, along with suppressed angiogenesis markers VEGF and NRAS. The MTF-MSN-treated group exhibited superior outcomes compared to free MTF and controls (p < 0.05). This innovative bioinspired MTF-MSN hydrogel system optimizes MTF delivery for melanoma therapy, pioneering advancements in drug repurposing and nano-oncology.

Less frequent skin ulcers among patients with Werner syndrome treated with pioglitazone: findings from the Japanese Werner Syndrome Registry

BACKGROUND AND AIM

Werner syndrome (WS) is an autosomal recessive, adult-onset, progeroid syndrome caused by WRN mutations. As refractory skin ulcers significantly affect the quality of life of patients with WS, this study identified ulcer risk factors and assessed prevention methods.

METHODS

We analyzed the data of 51 patients with WS enrolled in the Japanese Werner Syndrome Registry between 2016 and 2022. A cross-sectional analysis was performed to determine the association with skin ulcers at baseline. Statistical analyses were conducted, including Welch's and Pearson's chi-square tests. Age was adjusted using a logistic regression model.

RESULTS

The mean patient age was 48.8±7.6 years, and 66.7% of patients presented with skin ulcers. Univariate analysis showed that patients with skin ulcers were older than those without ulcers. Systolic blood pressure (SBP) was higher in patients with skin ulcers. Patients without skin ulcers received metformin and pioglitazone treatment significantly more often than those with ulcers. Logistic regression analysis adjusted for age showed that higher SBP remained a significant risk factor for skin ulcers. Patients administered pioglitazone had lower ulcer morbidity.

CONCLUSIONS

Age and SBP are risk factors for skin ulcers in patients with WS. Moreover, pioglitazone treatment may prevent skin ulcers.

A Systematic Review on Clinical Evidence for Topical Metformin: Old Medication With New Application

Background and Aims

Metformin is a widely used oral agent for controlling diabetes mellitus, but it also has other therapeutic benefits for various conditions. In addition, conventional oral metformin, and topical metformin have been used in, in-vitro studies in the treatment of acne, psoriasis, wound healing, and and so forth. While topical metformin has shown promising results in animal studies, there is limited data on its effectiveness in humans. Our study aims to summarize the clinical findings of human studies on the efficacy of topical metformin.

Methods

This review followed the PRISMA standards and systematically searched multiple databases using specific keywords. The relevant articles were selected according to the inclusions and exclusions criteria.

Results

Our search strategy yielded 1831 articles, after screening, 27 articles met our inclusion criteria which were: human studies, articles published before the start of the search, and topical forms of metformin. We also identified three additional relevant articles through reference checking. Therefore, our systematic review included a total of 30 articles.

Conclusion

Most commonly, topical metformin has been studied in dentistry and dermatology. In dentistry, it has been found effective in treating periodontitis when used with scaling and root planning. Combining metformin with platelet-rich fibrin can provide better benefits for furcation-involved teeth, and coating dental implants with metformin improves osseointegration. In dermatology, studies on melasma have had inconsistent results. Topical metformin has also shown promising results in promoting hair regrowth, wound healing, and acne vulgaris, suggesting it could be a potential treatment option for these conditions.

Efficacy and safety of a novel weekly topical metformin-loaded peel-off mask in the treatment of melasma: a split-face, placebo-controlled study

BACKGROUND

Melasma is a common condition that affects a patient's quality of life. Metformin is a cheap, well-tolerated and relatively safe medication that is widely prescribed for the treatment of diabetes. Topical metformin has shown promising results in treating melasma as well as several other dermatological conditions such as acne and recalcitrant central centrifugal cicatricial alopecia.

OBJECTIVES

To study the efficacy and safety of a once-weekly topical metformin-30%-loaded peel-off mask for treating melasma.

METHODS

Twenty female patients with melasma were recruited for the application of a metformin mask and placebo mask to either side of the face once weekly for 12 weeks. The hemi-Melasma Area Severity Index (hemi-MASI) was calculated at baseline, at each visit and 12 weeks after the end of treatment.

RESULTS

At baseline, the hemi-MASI score matched between both metformin and placebo sides [7.1 (SD 2.6) and 7.1 (SD 2.6), respectively, P = 0.99]. At the end of the active treatment period, the metformin side showed a significantly better improvement in hemi-MASI score in comparison with placebo [68% (SD 0.2%) improvement on the metformin side in contrast to 20% (SD 0.2%) on the placebo side]. Although scores decreased 3 months after stopping the active treatment [52% (SD 0.2%) improvement on the metformin side compared with the placebo side 15% (SD 0.2%)], they were still significantly better than baseline. No adverse effects were reported.

CONCLUSIONS

Topical metformin-loaded peel-off masks can be a promising, safe and effective treatment for melasma. Although applied only once weekly, metformin peel-off masks show comparable efficacy to previously reported daily usage formulations.

Sodium alginate/carboxymethylcellulose gel formulations containing Capparis sepieria plant extract for wound healing

Aim: Using appropriate wound dressings is crucial when treating burn wounds to promote accelerated healing.Materials & methods: Sodium alginate (SA)-based gels containing Carboxymethyl cellulose (CMC) and Pluronic F127 were prepared. The formulations. SA/CMC/Carbopol and SA/CMC/PluronicF127 were loaded with aqueous root extract of Capparis sepiaria. The formulations were characterized using appropriate techniques.Results: The gels' viscosity was in the range of 676.33 ± 121.76 to 20.00 ± 9.78 cP and in vitro whole blood kinetics showed their capability to induce a faster clotting rate. They also supported high cell viability of 80% with cellular migration and proliferation. Their antibacterial activity was significant against most bacteria strains used in the study.Conclusion: The gels' distinct features reveal their potential application as wound dressings for burn wounds.

Macrophage plasticity: signaling pathways, tissue repair, and regeneration

Macrophages are versatile immune cells with remarkable plasticity, enabling them to adapt to diverse tissue microenvironments and perform various functions. Traditionally categorized into classically activated (M1) and alternatively activated (M2) phenotypes, recent advances have revealed a spectrum of macrophage activation states that extend beyond this dichotomy. The complex interplay of signaling pathways, transcriptional regulators, and epigenetic modifications orchestrates macrophage polarization, allowing them to respond to various stimuli dynamically. Here, we provide a comprehensive overview of the signaling cascades governing macrophage plasticity, focusing on the roles of Toll-like receptors, signal transducer and activator of transcription proteins, nuclear receptors, and microRNAs. We also discuss the emerging concepts of macrophage metabolic reprogramming and trained immunity, contributing to their functional adaptability. Macrophage plasticity plays a pivotal role in tissue repair and regeneration, with macrophages coordinating inflammation, angiogenesis, and matrix remodeling to restore tissue homeostasis. By harnessing the potential of macrophage plasticity, novel therapeutic strategies targeting macrophage polarization could be developed for various diseases, including chronic wounds, fibrotic disorders, and inflammatory conditions. Ultimately, a deeper understanding of the molecular mechanisms underpinning macrophage plasticity will pave the way for innovative regenerative medicine and tissue engineering approaches.

Comparative study of Lepidium sativum orally administered seeds, hydrogel and atorvastatin on obesity of rats fed on a high fat diet

BACKGROUND

Obesity has become a prevalent issue worldwide, leading to various complications such as hyperlipidemia, diabetes, and cardiovascular problems. Statins, as FDA approved anti-hyperlipidemic drugs, still pose some concerns upon their administration. Recently, researchers have looked for natural products as an alternative to manage hyperlipidemia and obesity.

AIM

This work aimed to study the hypolipidemic effect of Lepidium sativum garden cress (GC) from different preparations; orally administered seeds, and hydrogel, in comparison to atorvastatin.

METHODS

GC hydrogel was prepared from the GC aqueous extract and pharmaceutically evaluated for its pH, spreadability, seeds content, homogeneity, rheology, and in vitro release. The rat's body weight, blood glucose levels, total lipid profile, and liver biomarkers were evaluated on obese rats for one month. In addition, the histopathology study was also performed.

RESULTS

GC hydrogel had acceptable pharmaceutical properties and showed a sustained release performance over 24 h. Oral and topical GC significantly reduced the lipid profiles, blood sugar and ALT, AST levels more than the negative control group and comparable to atorvastatin. It was found that oral GC showed a significant effect on the percentage decrease in the rat's body weight than the applied hydrogel. Histopathology study revealed a better outcome in the histological structure of pancreas and liver compared with rats feed on high fat diet post-treatment for one month.

CONCLUSION

GC orally administered, or topically applied hydrogel could be a promising, safe alternative formulation to atorvastatin in managing hyperlipidemia and normalizing body weight of obese rats.

Exploiting of Green Synthesized Metal Oxide Nanoparticles in the Potentiometric Determination of Metformin Hydrochloride in Pharmaceutical Products

The advanced and highly functional properties of Al2O3 and NiO nanoparticles promote the widespread use of metal oxides as remarkable electroactive materials for sensing and electrochemical applications. The proposed study describes a comparison of the sensitivity and selectivity of two modified wire membrane sensors enriched with Al2O3 and NiO nanoparticles with conventional wire membranes for the quantification of the antidiabetic drug metformin hydrochloride (MTF). The results show linear relationships of the enriched Al2O3 and NiO nanosensors over the concentration ranges 1.0 × 10-10-1.0 × 10-2 mol L-1 and 1.0 × 10-6-1.0 × 10-2 M for both the modified sensors and the conventional coated wire membrane sensors. The regression equations were EmV = (52.1 ± 0.5) log (MTF) + 729 for enriched nanometallic oxides, EmV = (57.04 ± 0.4) log (MTF) + 890.66, and EmV = (58.27 ± 0.7) log (MTF) + 843.27 with correlation coefficients of 0.9991, 0.9997, and 0.9998 for the aforementioned sensors, respectively. The proposed method was fully validated with respect to the recommendations of the International Union of Pure and Applied Chemistry (IUPAC). The newly functionalized sensors have been successfully used for the determination of MTF in its commercial products.

Chitosan based hybrid superabsorbent for controlled drug delivery application

In the present study, a hybrid chitosan-alginate superabsorbent is prepared using maleic acid as a cross-linker and acrylamide as a grafting agent using the free radical mechanism. The composite hydrogel shows good swelling capacity along with hemocompatibility and biocompatibility and hence it is utilized as a drug delivery device. The characterization techniques including x-ray diffraction, Fourier transform infrared, x-ray photoelectron spectroscopy, and thermal analysis indicate the successful synthesis of stable hydrogel with rich functionalities. Metformin hydrochloride is used as a model drug which is used to treat diabetes. The drug encapsulation is done using the swelling diffusion method after the synthesis of hydrogel. The release of metformin from the drug-loaded hydrogel at physiological pH highlights the role of non-covalent interactions between the drug and hydrogel. In vitro release studies of Metformin from the drug-loaded hydrogel show higher release profiles at intestinal pH (7.4) compared to stomach pH (1.2). The observed cumulative release is 82.71% at pH 7.4 and 45.67% at pH 1.2 after 10 h. Brunauer-Emmett-Teller analysis reveals the effect of surface area, pore size, and pore volume of hydrogel on the drug release. The drug release from the hybrid chitosan-alginate hydrogel is found to be more sustained in comparison to the pure chitosan hydrogel. For the present drug delivery system, the swelling-controlled release is found to be more dominating than the pH-controlled release. The synthesized hydrogel can be successfully employed as a potential drug delivery system for controlled drug delivery.

In Vitro and In Vivo Evaluation of Metformin Hydrochloride Hydrogels Developed with Experimental Design in the Treatment of Burns

Burns alter the normal skin barrier and affect various host defense processes that help prevent infections. An ineffective repair process can lead to serious damage, such as the onset of an infection or skin loss, which can then harm the surrounding tissues and ultimately the entire organism. This study aims to prepare in situ gels containing metformin hydrochloride, a compound known for its wound healing properties. To achieve this, in situ gels were prepared using three different gelling agents (Poloxamer 407®, Carbopol 934®, and sodium carboxymethyl cellulose (Na-CMC)) and three different concentrations of metformin hydrochloride (4 mg/g, 6 mg/g, and 8 mg/g), which were optimized through experimental design. Metformin concentration and gelling agent type were independent variables, and the loaded amount and the percentage of metformin released after 150 min were chosen as dependent variables in the optimization process. After determining the optimum values of the dependent variables according to the ANOVA analysis results, in vivo studies were conducted with optimized hydrogel formulations. Two groups, each consisting of seven Wistar rats with a burn model, were treated with metformin-poloxamer 407® gels at doses of 4 mg/g and 8 mg/g for 29 days. The results were then compared to untreated and placebo gel groups. Rats treated with in situ Poloxamer 407® hydrogels containing metformin hydrochloride showed a significant reduction in the size of the burned area after 29 days of treatment. However, for a comprehensive understanding of the wound healing mechanism, further studies such as immuno-histochemical and cell culture studies are needed.

Targeting the NOD-Like Receptor Pyrin Domain Containing 3 Inflammasome to Improve Healing of Diabetic Wounds

Significance: Chronic skin wounds are a significant health problem around the world, often leading to amputation and even death. Although persistent inflammation is a hallmark of these poorly healing wounds, few available therapies have been designed to target inflammation. In this review, we summarize available evidence of the role of the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome in impaired wound healing and describe strategies to inhibit the inflammasome to improve wound healing. Recent Advances: The NLRP3 inflammasome plays an important physiological role in skin wound healing, during which transient inflammasome activity contributes to both epidermal and dermal healing. In contrast, sustained activity of the NLRP3 inflammasome leads to impaired epidermal and dermal healing associated with diabetes. Of importance, preclinical studies have demonstrated that inhibiting the NLRP3 inflammasome-induced resolution of inflammation, increased granulation tissue formation and collagen deposition, and accelerated reepithelialization and wound closure. Critical Issues: NLRP3 inflammasome inhibitors have appealing potential for translation into therapies for chronic wounds. Although preclinical studies have shown promising results, there is a need for human/clinical studies to evaluate dosing formulations, potential therapeutic effects, dose-response relationships, and possible side effects. Future Directions: Among strategies to inhibit the NLRP3 inflammasome, glyburide, metformin, peroxisome proliferator-activated receptor agonists, and the dipeptidyl peptidase 4 inhibitor saxagliptin appear to be closest to clinical translation, as these drugs are already Food and Drug Administration approved for other indications. Future clinical studies are needed to develop topical formulations of these drugs, and to assess the safety and efficacy of these inhibitors, to improve healing of chronic wounds.

Topical metformin 30% gel in the treatment of acne vulgaris in women, a split face, placebo-controlled study

Acne vulgaris (AV), a widely common disorder, that negatively affects the quality of life. Metformin is a relatively safe, cheap and well tolerated drug that is widely used in the treatment of Diabetes. Systemic metformin has demonstrated promising results in treating acne, while topically it was studied for melasma and recalcitrant central centrifugal cicatricial alopecia. To study the safety and efficacy of topical metformin 30% in the treatment of AV. Twenty-seven female AV patients were asked to blindly apply metformin and placebo gels to either side of the face for 12 weeks. AV lesion count was performed at baseline, at each visit and 4 weeks after end of treatment. At the end of the treatment period, the treated side showed significant improvement of comedones, papules and nodules but not pustules. Although, lesions count increased 1 month after stopping treatment, comedones and papules numbers were still significantly less on the metformin side compared to placebo. No side effects were reported. The limited number of patients studied and the limited follow-up period. The metformin effect was not studied on cellular and molecular levels. Topical metformin nanoemulsion gel can be a promising safe and effective treatment of AV.

The Effect of Metformin on Chemotherapy-Induced Toxicities in Non-diabetic Breast Cancer Patients: A Randomised Controlled Study

BACKGROUND AND OBJECTIVE

Breast cancer patients treated with adriamycin-cyclophosphamide plus paclitaxel (AC-T) are often challenged with serious adverse effects for which no effective therapies are available. Here, we investigated whether metformin, an antidiabetic drug with additional pleiotropic effects could favourably offset AC-T induced toxicities.

PATIENTS AND METHODS

Seventy non-diabetic breast cancer patients were randomised to receive either AC-T (adriamycin 60 mg/m² + cyclophosphamide 600 mg/m² × 4 cycles Q21 days, followed by weekly paclitaxel 80 mg/m² × 12 cycles) alone or AC-T plus metformin (1700 mg/day). Patients were assessed regularly after each cycle to record the incidence and severity of adverse events based on the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), version 5.0. Moreover, baseline echocardiography and ultrasonography were done and repeated after the end of neoadjuvant therapy.

RESULTS

Addition of metformin to AC-T resulted in significantly less incidence and severity of peripheral neuropathy, oral mucositis, and fatigue (p < 0.05) compared to control arm. Moreover, the left ventricular ejection fraction (LVEF%) in the control arm dropped from a mean of 66.69 ± 4.57 to 62.2 ± 5.22% (p = 0.0004) versus a preserved cardiac function in the metformin arm (64.87 ± 4.84 to 65.94 ± 3.44%, p = 0.2667). Furthermore, fatty liver incidence was significantly lower in metformin compared with control arm (8.33% vs 51.85%, p = 0.001). By contrast, haematological disturbances caused by AC-T were preserved after concurrent metformin administration (p > 0.05).

CONCLUSION

Metformin offers a therapeutic opportunity for controlling toxicities caused by neoadjuvant chemotherapy in non-diabetic breast cancer patients.

TRIAL REGISTRATION

This randomised controlled trial was registered on November 20, 2019 in ClinicalTrials.gov under registration number: NCT04170465.

Carboxymethyl cellulose/poloxamer gels enriched with essential oil and Ag nanoparticles: promising wound dressings

Aim: Essential oils are promising antibacterial and wound-healing agents that should be explored for the design of wound dressings. Materials & methods: Topical gels prepared from a combination of carboxymethyl cellulose and poloxamer were incorporated with tea tree and lavender oil together with Ag nanoparticles. In vitro release, cytotoxicity, antibacterial, and wound healing studies were performed. Results: The gels displayed good spreadability with viscosity in the range of 210-1200 cP. The gels displayed promising antibacterial activity against selected Gram-positive and Gram-negative bacteria used in the study. The % cell viability of the gels was more than 90.83%. Conclusion: The topical gels displayed excellent wound closure in vitro revealing that they are potential wound dressings for bacteria-infected wounds.

The contribution of immunohistochemistry to the development of hydrogels for skin repair and regeneration

Hydrogels based on various polymeric materials have been successfully developed in recent years for a variety of skin applications. Several studies have shown that hydrogels with regenerative, antibacterial, and antiinflammatory properties can provide faster and better healing outcomes, particularly in chronic diseases where the normal physiological healing process is significantly hampered. Various experimental tests are typically performed to assess these materials' ability to promote angiogenesis, re-epithelialization, and the production and maturation of new extracellular matrix. Immunohistochemistry is important in this context because it allows for the visualization of in situ target tissue factors involved in the various stages of wound healing using antibodies labelled with specific markers detectable with different microscopy techniques. This review provides an overview of the various immunohistochemical techniques that have been used in recent years to investigate the efficacy of various types of hydrogels in assisting skin healing processes. The large number of scientific articles published demonstrates immunohistochemistry's significant contribution to the development of engineered biomaterials suitable for treating skin injuries.

Efficacy of Graphene-Based Nanocomposite Gels as a Promising Wound Healing Biomaterial

The development of biocompatible nanocomposite hydrogels with effective wound healing/microbicidal properties is needed to bring out their distinguished characteristics in clinical applications. The positive interaction between graphene oxide/reduced graphene oxide (GO/rGO) and hydrogels and aloe vera gel represents a strong strategy for the advancement of therapeutic approaches for wound healing. In this study, the synthesis, characterization, and angiogenic properties of graphene-based nanocomposite gels have been corroborated and substantiated through several in vitro and in vivo assays. In this respect, graphene oxide was synthesized by incorporating a modified Hummer's method and ascertained by Raman spectroscopy. The obtained GO and rGO were uniformly dispersed into the aloe vera gel and hydrogel, respectively, as wound healing materials. These formulations were characterized via in vitro bio-chemical techniques and were found suitable for the appropriate cell viability, attachment, and proliferation. In addition, in vivo experiments were conducted using male Wistar rats. This revealed that the GO/rGO-based gels stimulated wound contraction and re-epithelialization compared to that of the non-treatment group. From the study, it is suggested that GO/rGO-based aloe vera gel can be recommended as a promising candidate for wound healing applications.

Dose-dependent immunomodulatory effects of metformin on human neonatal monocyte-derived macrophages

While the association of inflammation with bronchopulmonary dysplasia (BPD) has long been appreciated, M1 proinflammatory macrophage population is emerging as the key element in driving the BPD inflammatory environment. Previous study suggests that low-dose metformin elicits an anti-inflammatory response, possibly through modulating macrophages, to improve disease outcome in a rat BPD model. To investigate this concept further, we examined the dose-dependent immunomodulatory function of metformin directly on human macrophages derived from cord blood (CB) monocytes. We demonstrate that low-dose metformin promotes expansion of M2 anti-inflammatory macrophages, contrasted with high-dose treatment, which exacerbates inflammation by favoring M1 polarization and restricting M2 phenotype. These findings highlight that metformin hold immunomodulatory ability by regulating macrophage polarization in a dose-dependent manner, and only when applied at low dose, exhibiting potential for beneficial anti-inflammatory adjuvant in BPD setting.

Bioactive anti-inflammatory antibacterial metformin-contained hydrogel dressing accelerating wound healing

Highly efficient wound healing and skin regeneration remain a challenge. Long-term inflammation and bacterial infection can inhibit the healing process and lead to the scar formation. Here, we report a hydrogel (FEM) formed by self-assembly of ε-poly-l-lysine-F127-ε-poly-l-lysine (EPL-F127-EPL) and metformin for wound repair. Especially, the role of metformin-based antibacterial hydrogel in wound healing and repair was investigated for the first time. FEM has inherent multifunctional properties, including controlled metformin release, anti-inflammatory and antibacterial activity, temperature responsiveness, injectable and self-healing capabilities. The in vivo results showed that FEM dressings accelerated the wound healing by stimulating the angiogenesis process of the wound tissue and anti-inflammation. This study shows that the multifunctional metformin-contained hydrogel scaffolds could enhance the wound repair through the anti-inflammation and accelerated angiogenesis, which could also expand the biomedical applications of metformin-based biomaterials.

Topical application of metformin accelerates cutaneous wound healing in streptozotocin-induced diabetic rats

BACKGROUND

Diabetic chronic wound, which is one of the diabetic complications caused by hyperglycemia, characterized by prolonged inflammation has become one of the most serious challenges in the clinic. Hyperglycemia during diabetes not only causes prolonged inflammation and delayed wound healing but also modulates the activation of nuclear factor-kappa B (NF-κB) and the expression of matrix metalloproteinases (MMPs). Although metformin is the oldest oral antihyperglycemic drug commonly used for treating type 2 diabetes, few studies have explored the molecular mechanism of its topical effect on wound healing. Therefore, we aimed to investigate the molecular effects of topical metformin application on delayed wound healing, which's common in diabetes.

METHODS AND RESULTS

In this context, we created a full-thickness excisional wound model in Wistar albino rats and, investigated NF-κB p65 DNA-binding activity and expression levels of RELA (p65), MMP2 and MMP9 in wound samples taken on days 0, 3, 7, and 14 from diabetic/non-diabetic rats treated with metformin and saline. As a result of our study, we showed that topically applied metformin accelerates wound healing by suppressing NF-κB p65 activity and diminishing the expression of MMP2 and MMP9.

CONCLUSIONS

Diabetic wounds treated with metformin healed even faster than those in the control group that mimicked standard wound healing.

Possible treatment for UVB-induced skin injury: Anti-inflammatory and cytoprotective role of metformin in UVB-irradiated keratinocytes

BACKGROUND

Excessive inflammation and cell death induced by ultraviolet (UV) cause skin photodamage. Metformin possesses anti-inflammatory and cytoprotective effects. However, whether metformin inhibits inflammation and cell death in UVB-induced acute skin damage is unclear.

OBJECTIVE

To evaluate the anti-inflammatory and cytoprotective effects of metformin in vitro and in vivo. Furthermore, its potential mechanism has been explored.

METHODS

Transcriptome sequencing and multiplex cytokines analysis were used to evaluate the validity of in vitro UVB-induced acute damage keratinocyte model and anti-inflammatory effects of metformin. We also determined the expression and nuclear translocation of CCAAT/enhancer-binding protein beta (C/EBPβ), an important transcriptional factor of Interleukin-1beta (IL-1β). Cell viability and cell death of keratinocytes were evaluated upon UVB irradiation in the presence or absence of metformin. 0.6% metformin cream was applied on UVB-irradiated mice to explore its pharmacological effects in vivo.

RESULTS

Transcriptional landscape of 50 mJ/cm² UVB-irradiated HaCaT cells is typical of UVB-induced acute damage keratinocyte model in vitro. Metformin alleviated transcription and secretion of IL-1β, Tumor Necrosis Factor-alpha, and Fibroblast Growth Factor 2, expression and nuclear translocation of C/EBPβ in this model. Metformin also protected keratinocytes from cell death caused by UVB-induced cellular secretions, which contributed to its cytoprotective effects. Topical administration of 0.6% metformin cream alleviated UVB-induced skin damage in mice.

CONCLUSION

We proved the protective roles of metformin in UVB-challenged keratinocytes and UVB-irradiated mice, which indicated the potential value of metformin in topical therapy against skin photodamage.

The Treatment of Impaired Wound Healing in Diabetes: Looking among Old Drugs

Chronic wounds often occur in patients with diabetes mellitus due to the impairment of wound healing. This has negative consequences for both the patient and the medical system and considering the growing prevalence of diabetes, it will be a significant medical, social, and economic burden in the near future. Hence, the need for therapeutic alternatives to the current available treatments that, although various, do not guarantee a rapid and definite reparative process, appears necessary. We here analyzed current treatments for wound healing, but mainly focused the attention on few classes of drugs that are already in the market with different indications, but that have shown in preclinical and few clinical trials the potentiality to be used in the treatment of impaired wound healing. In particular, repurposing of the antiglycemic agents dipeptidylpeptidase 4 (DPP4) inhibitors and metformin, but also, statins and phenyotin have been analyzed. All show encouraging results in the treatment of chronic wounds, but additional, well designed studies are needed to allow these drugs access to the clinics in the therapy of impaired wound healing.

Anthocyanins rich pomegranate cream as a topical formulation with anti-aging activity

Background: Anthocyanins are antioxidant compounds constitute the primary dyes of the pomegranate arils. Anthocyanins could protect the aged skin induced by oxidant exposure as a major role in aging processing and skin degeneration.Purpose: The study aimed to evaluate the anti-aging activity of anthocyanins rich pomegranate (Punica granatum) after formulated into a topical cream. Also, its effect on human dermal fibroblast function and epidermal keratinocyte were evaluated.Method: Anthocyanins were extracted from fresh pomegranate arils using acidified methanol and were purified by Sephadex LH-20 gel-column chromatography. Further, the fusion method was used to prepare cold cream containing pomegranate anthocyanins. The formulated cream was evaluated for their compatibility study, irritation, homogeneity, drug content, drug release, and stability tests. Furthermore, permeation study through abdominal rabbits, as well as Human application was performed.Results: Compatibility study showed the absence of any interaction between anthocyanins and the used polymers. The formulated cream was nonirritant, homogenous and potentially reduced skin aging when applied to Human volunteers' skin. Furthermore, the skin permeation displayed a good permeation of 43.16% after 210 min.Conclusion: Pomegranate anthocyanins could be used as a safe, stable, homogeneous, nonirritant and effective topical anti-aging drug formulation for aged human people.