Combined effect of substance P and curcumin on cutaneous wound healing in diabetic rats

Evaluation of Antimicrobial Activity of Selected Plant Extracts against Staphylococcus Strains Isolated from Wound Infections

Wound infections are a significant medical problem, with Staphylococcus species being one of the most common etiological factors. Treatment is complex due to bacterial antibiotic resistance and the ability to form a biofilm. The aim of this study was to determine the drug susceptibility of the clinical isolates of Staphylococcus species obtained from wound infections, assess their ability to form a biofilm in vitro, evaluate the level of extracellular slime synthesis, and test the antistaphylococcal properties of selected plant extracts against plate-cultured bacteria and activity against mature biofilms. A total of 20 Staphylococcus strains were evaluated. The antibiotic susceptibility and sensitivity of the strains to the tested extracts were determined using the disc diffusion method. The production of extracellular bacterial slime was assessed using Congo Red agar plates. The biofilm formation and the effect of plant extracts on the biofilm layer were examined using the MTT method on polystyrene microtiter plates. Diverse drug susceptibility profiles, slime production ability, and in vitro biofilm formation were observed among the tested strains. It was found that aqueous extracts from the Serpylli herba, Arctii lappae folium, Taraxaci folium, and Galii aparini herba showed antibacterial activity against some of the tested strains. In contrast, their antibiofilm activity was not confirmed. Among all tested preparations, the most promising antimicrobial extracts in both planktonic cultures and biofilm were Thymus serpyllum herb and Taraxacum officinale leaf extracts. These results allowed us to conclude their potential application in medicine to support the treatment of challenging wound conditions.

Immunomodulatory poly(L-lactic acid) nanofibrous membranes promote diabetic wound healing by inhibiting inflammation, oxidation and bacterial infection

Background

Given the significant impact on human health, it is imperative to develop novel treatment approaches for diabetic wounds, which are prevalent and serious complications of diabetes. The diabetic wound microenvironment has a high level of reactive oxygen species (ROS) and an imbalance between proinflammatory and anti-inflammatory cells/factors, which hamper the healing of chronic wounds. This study aimed to develop poly(L-lactic acid) (PLLA) nanofibrous membranes incorporating curcumin and silver nanoparticles (AgNPs), defined as PLLA/C/Ag, for diabetic wound healing.

Methods

PLLA/C/Ag were fabricated via an air-jet spinning approach. The membranes underwent preparation and characterization through various techniques including Fourier-transform infrared spectroscopy, measurement of water contact angle, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, assessment of in vitro release of curcumin and Ag+, testing of mechanical strength, flexibility, water absorption and biodegradability. In addition, the antioxidant, antibacterial and anti-inflammatory properties of the membranes were evaluated in vitro, and the ability of the membranes to heal wounds was tested in vivo using diabetic mice.

Results

Loose hydrophilic nanofibrous membranes with uniform fibre sizes were prepared through air-jet spinning. The membranes enabled the efficient and sustained release of curcumin. More importantly, antibacterial AgNPs were successfully reduced in situ from AgNO3. The incorporation of AgNPs endowed the membrane with superior antibacterial activity, and the bioactivities of curcumin and the AgNPs gave the membrane efficient ROS scavenging and immunomodulatory effects, which protected cells from oxidative damage and reduced inflammation. Further results from animal studies indicated that the PLLA/C/Ag membranes had the most efficient wound healing properties, which were achieved by stimulating angiogenesis and collagen deposition and inhibiting inflammation.

Conclusions

In this research, we successfully fabricated PLLA/C/Ag membranes that possess properties of antioxidants, antibacterial agents and anti-inflammatory agents, which can aid in the process of wound healing. Modulating wound inflammation, these new PLLA/C/Ag membranes serve as a novel dressing to enhance the healing of diabetic wounds.

Progress in the Use of Hydrogels for Antioxidant Delivery in Skin Wounds

The skin is the largest organ of the body, and it acts as a protective barrier against external factors. Chronic wounds affect millions of people worldwide and are associated with significant morbidity and reduced quality of life. One of the main factors involved in delayed wound healing is oxidative injury, which is triggered by the overproduction of reactive oxygen species. Oxidative stress has been implicated in the pathogenesis of chronic wounds, where it is known to impair wound healing by causing damage to cellular components, delaying the inflammatory phase of healing, and inhibiting the formation of new blood vessels. Thereby, the treatment of chronic wounds requires a multidisciplinary approach that addresses the underlying causes of the wound, provides optimal wound care, and promotes wound healing. Among the promising approaches to taking care of chronic wounds, antioxidants are gaining interest since they offer multiple benefits related to skin health. Therefore, in this review, we will highlight the latest advances in the use of natural polymers with antioxidants to generate tissue regeneration microenvironments for skin wound healing.

Technological Interventions Enhancing Curcumin Bioavailability in Wound-Healing Therapeutics

Wound healing has been a challenge in the medical field. Tremendous research has been carried out to expedite wound healing by fabricating various formulations, some of which are now commercially available. However, owing to their natural source, people have been attracted to advanced formulations with herbal components. Among various herbs, curcumin has been the center of attraction from ancient times for its healing properties due to its multiple therapeutic effects, including antioxidant, antimicrobial, anti-inflammatory, anticarcinogenic, neuroprotective, and radioprotective properties. However, curcumin has a low water solubility and rapidly degrades into inactive metabolites, which limits its therapeutic efficacy. Henceforth, a carrier system is needed to carry curcumin, guard it against degradation, and keep its bioavailability and effectiveness. Different formulations with curcumin have been synthesized, and exist in the form of various synthetic and natural materials, including nanoparticles, hydrogels, scaffolds, films, fibers, and nanoemulgels, improving its bioavailability dramatically. This review discusses the advances in different types of curcumin-based formulations used in wound healing in recent times, concentrating on its mechanisms of action and discussing the updates on its application at several stages of the wound healing process. Impact statement Curcumin is a herbal compound extracted from turmeric root and has been used since time immemorial for its health benefits including wound healing. In clinical formulations, curcumin shows low bioavailability, which mainly stems from the way it is delivered in the body. Henceforth, a carrier system is needed to carry curcumin, guard it against degradation, while maintaining its bioavailability and therapeutic efficacy. This review offers an overview of the advanced technological interventions through tissue engineering approaches to efficiently utilize curcumin in different types of wound healing applications.

Insights into the mechanisms of diabetic wounds: pathophysiology, molecular targets, and treatment strategies through conventional and alternative therapies

Diabetes mellitus is a prevalent cause of mortality worldwide and can lead to several secondary issues, including DWs, which are caused by hyperglycemia, diabetic neuropathy, anemia, and ischemia. Roughly 15% of diabetic patient's experience complications related to DWs, with 25% at risk of lower limb amputations. A conventional management protocol is currently used for treating diabetic foot syndrome, which involves therapy using various substances, such as bFGF, pDGF, VEGF, EGF, IGF-I, TGF-β, skin substitutes, cytokine stimulators, cytokine inhibitors, MMPs inhibitors, gene and stem cell therapies, ECM, and angiogenesis stimulators. The protocol also includes wound cleaning, laser therapy, antibiotics, skin substitutes, HOTC therapy, and removing dead tissue. It has been observed that treatment with numerous plants and their active constituents, including Globularia Arabica, Rhus coriaria L., Neolamarckia cadamba, Olea europaea, Salvia kronenburgii, Moringa oleifera, Syzygium aromaticum, Combretum molle, and Myrtus communis, has been found to promote wound healing, reduce inflammation, stimulate angiogenesis, and cytokines production, increase growth factors production, promote keratinocyte production, and encourage fibroblast proliferation. These therapies may also reduce the need for amputations. However, there is still limited information on how to prevent and manage DWs, and further research is needed to fully understand the role of alternative treatments in managing complications of DWs. The conventional management protocol for treating diabetic foot syndrome can be expensive and may cause adverse side effects. Alternative therapies, such as medicinal plants and green synthesis of nano-formulations, may provide efficient and affordable treatments for DWs.

Targeting endothelial cells with golden spice curcumin: A promising therapy for cardiometabolic multimorbidity

Cardiometabolic multimorbidity (CMM) is an increasingly significant global public health concern. It encompasses the coexistence of multiple cardiometabolic diseases, including hypertension, stroke, heart disease, atherosclerosis, and T2DM. A crucial component to the development of CMM is the disruption of endothelial homeostasis. Therefore, therapies targeting endothelial cells through multi-targeted and multi-pathway approaches hold promise for preventing and treatment of CMM. Curcumin, a widely used dietary supplement derived from the golden spice Carcuma longa, has demonstrated remarkable potential in treatment of CMM through its interaction with endothelial cells. Numerous studies have identified various molecular targets of curcumin (such as NF-κB/PI3K/AKT, MAPK/NF-κB/IL-1β, HO-1, NOs, VEGF, ICAM-1 and ROS). These findings highlight the efficacy of curcumin as a therapeutic agent against CMM through the regulation of endothelial function. It is worth noting that there is a close relationship between the progression of CMM and endothelial damage, characterized by oxidative stress, inflammation, abnormal NO bioavailability and cell adhesion. This paper provides a comprehensive review of curcumin, including its availability, pharmacokinetics, pharmaceutics, and therapeutic application in treatment of CMM, as well as the challenges and future prospects for its clinical translation. In summary, curcumin shows promise as a potential treatment option for CMM, particularly due to its ability to target endothelial cells. It represents a novel and natural lead compound that may offer significant therapeutic benefits in the management of CMM.

Thermosensitive and antioxidant wound dressings capable of adaptively regulating TGFβ pathways promote diabetic wound healing

Various therapies have been utilized for treating diabetic wounds, yet current regiments do not simultaneously address the key intrinsic causes of slow wound healing, i.e., abnormal skin cell functions (particularly migration), delayed angiogenesis, and chronic inflammation. To address this clinical gap, we develop a wound dressing that contains a peptide-based TGFβ receptor II inhibitor (PTβR2I), and a thermosensitive and reactive oxygen species (ROS)-scavenging hydrogel. The wound dressing can quickly solidify on the diabetic wounds following administration. The released PTβR2I inhibits the TGFβ1/p38 pathway, leading to improved cell migration and angiogenesis, and decreased inflammation. Meanwhile, the PTβR2I does not interfere with the TGFβ1/Smad2/3 pathway that is required to regulate myofibroblasts, a critical cell type for wound healing. The hydrogel's ability to scavenge ROS in diabetic wounds further decreases inflammation. Single-dose application of the wound dressing significantly accelerates wound healing with complete wound closure after 14 days. Overall, using wound dressings capable of adaptively modulating TGFβ pathways provides a new strategy for diabetic wound treatment.

Targeting matrix metalloproteases in diabetic wound healing

Chronic inflammation participates in the progression of multiple chronic diseases, including obesity, diabetes mellitus (DM), and DM related complications. Diabetic ulcer, characterized by chronic wounds that are recalcitrant to healing, is a serious complication of DM tremendously affecting the quality of life of patients and imposing a costly medical burden on society. Matrix metalloproteases (MMPs) are a family of zinc endopeptidases with the capacity of degrading all the components of the extracellular matrix, which play a pivotal part in healing process under various conditions including DM. During diabetic wound healing, the dynamic changes of MMPs in the serum, skin tissues, and wound fluid of patients are in connection with the degree of wound recovery, suggesting that MMPs can function as essential biomarkers for the diagnosis of diabetic ulcer. MMPs participate in various biological processes relevant to diabetic ulcer, such as ECM secretion, granulation tissue configuration, angiogenesis, collagen growth, re-epithelization, inflammatory response, as well as oxidative stress, thus, seeking and developing agents targeting MMPs has emerged as a potential way to treat diabetic ulcer. Natural products especially flavonoids, polysaccharides, alkaloids, polypeptides, and estrogens extracted from herbs, vegetables, as well as animals that have been extensively illustrated to treat diabetic ulcer through targeting MMPs-mediated signaling pathways, are discussed in this review and may contribute to the development of functional foods or drug candidates for diabetic ulcer therapy. This review highlights the regulation of MMPs in diabetic wound healing, and the potential therapeutic ability of natural products for diabetic wound healing by targeting MMPs.

Local administration of curcumin-loaded nanoparticles enhances periodontal repair in vivo

The aim was to assess the influence of local application of curcumin-loaded nanoparticles on an experimental model of periodontal repair. Periodontitis was induced by ligatures on both lower first molars of rats. After 15 days, ligatures were removed ("treatment") and animals were randomly allocated to three experimental groups (n = 8/group): (i) 0.05 mg/ml curcumin-loaded nanoparticles, (ii) empty nanoparticles (vehicle control), and (iii) sterile saline (negative control). Experimental treatments were administered locally on days 0, 3, 5, 7, 9, and 11 after ligature removal. Animals were euthanized at 7 and 14 days. Bone repair was assessed by microcomputer tomography (µCT). Histological sections were stained with hematoxylin/eosin (H/E), Picrosirius Red, and Masson's trichrome. Expression of Runx-2 was studied by immunohistochemistry. Gene expression of Itgam, Arg1, and Inos was assessed by RT-qPCR. At 7 days, there was increased gene expression of Itgam and Arg1 and of the relative expression of Arg1/Inos in curcumin-treated animals, but no difference in any other outcomes. At 14 days, curcumin-loaded nanoparticles significantly increased bone repair and collagen content, as well as the number of osteocytes, percentage of extracellular matrix, and expression of Runx2. The results demonstrate that local administration of curcumin-loaded nanoparticles enhanced tissue repair in an experimental model of periodontal repair. Nanoparticle-encapsulated curcumin enhances early post-treatment repair of periodontal tissues.

The neuropeptide substance P/neurokinin-1 receptor system and diabetes: From mechanism to therapy

Diabetes is a significant public health issue known as the world's fastest-growing disease condition. It is characterized by persistent hyperglycemia and subsequent chronic complications leading to organ dysfunction and, ultimately, the failure of target organs. Substance P (SP) is an undecapeptide that belongs to the family of tachykinin (TK) peptides. The SP-mediated activation of the neurokinin 1 receptor (NK1R) regulates many pathophysiological processes in the body. There is also a relation between the SP/NK1R system and diabetic processes. Importantly, deregulated expression of SP has been reported in diabetes and diabetes-associated chronic complications. SP can induce both diabetogenic and antidiabetogenic effects and thus affect the pathology of diabetes destructively or protectively. Here, we review the current knowledge of the functional relevance of the SP/NK1R system in diabetes pathogenesis and its exploitation for diabetes therapy. A comprehensive understanding of the role of the SP/NK1R system in diabetes is expected to shed further light on developing new therapeutic possibilities for diabetes and its associated chronic conditions.

Resina Draconis extract exerts anti-HCC effects through METTL3-m6A-Survivin axis

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Herbal medicines have become an important treasure reservoir for anti-HCC drugs because of their high efficiency and low toxicity. Herein, we investigated whether a 75% ethanol extract from Resina Draconis (ERD) exhibited comprehensive anti-HCC effects both in vivo and in vitro. We revealed that ERD effectively inhibited proliferation and triggered apoptosis of HCC cells in a dose- and time-dependent maner, posing no apparent apoptotic toxicity to normal liver cells. Moreover, ERD significantly inhibited the migration, invasion and metastasis of HCC cells. Importantly, ERD treatment effectively inhibited the growth of xenograft HCC in nude mice with low toxicity and low side effects. Molecular mechanism analysis showed that ERD strongly reduced the expression of anti-apoptotic protein Survivin, ultimately leading to the cleavage activation of apoptosis executive proteins such as Caspase 3 and Poly (ADP-ribose) polymerase (PARP). Survivin gene silencing apparently sensitized the apoptotic effect induced by ERD. Further experiments revealed that ERD inhibited N6-methyladenosine (m⁶ A) modification in Survivin mRNA by downregulating Methyltransferase-like 3 (METTL3) expression and reducing the binding rate of METTL3 and Survivin mRNA. Together, our findings suggest that ERD can be severed as a novel anti-HCC natural product by targeting METTL3-m⁶ A-Survivin axis.

The Regenerative Potential of Substance P

Wound healing is a highly coordinated process which leads to the repair and regeneration of damaged tissue. Still, numerous diseases such as diabetes, venous insufficiencies or autoimmune diseases could disturb proper wound healing and lead to chronic and non-healing wounds, which are still a great challenge for medicine. For many years, research has been carried out on finding new therapeutics which improve the healing of chronic wounds. One of the most extensively studied active substances that has been widely tested in the treatment of different types of wounds was Substance P (SP). SP is one of the main neuropeptides released by nervous fibers in responses to injury. This review provides a thorough overview of the application of SP in different types of wound models and assesses its efficacy in wound healing.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Compendium of Conventional and Targeted Drug Delivery Formulation Used for the Treatment and Management of the Wound Healing

Wound healing is a complex and dynamic phenomenon that involves the restoration of normal physiology and functioning of injured tissue. The process of wound healing is primarily regulated by various cytokines, inflammatory mediators, and growth factors at the molecular level. Any intervention in the normal wound healing process leads to further tissue damage, which in turn leads to delayed wound healing. Several natural, synthetic drugs and their combinations were used to restored and accelerate the wound healing process. However, the conventional delivery carriers were not much effective, and thus, nowadays, nanocarriers are gaining much popularity since they are playing a pivotal role in drug delivery. Since nanocarriers have their own applicability and benefits (enhance the bioavailability, site-specific targeting) so, they can accelerate wound healing more efficiently. This review briefly discussed about the various events that take place during the wound healing process with emphasis on various natural, synthetic, and combination drug therapy used for accelerating wound healing and the role of nanotechnology-based approaches in chronic wound healing.

Neuropeptides, Inflammation, Biofilms, and diabetic Foot Ulcers

A diabetic foot ulcer (DFU) is a serious complication in patients with diabetes mellitus (DM). A DFU is the most common cause of non-traumatic limb amputation, and patients with DFUs have increased mortality rates within 5 years after amputation. DFUs also increase the risk of cardiovascular and cerebrovascular diseases; therefore, with the increasing incidence and prevalence of diabetic foot wounds, DFUs are gradually becoming a major public health problem. The pathophysiology of DFUs is complicated and remains unclear. In recent years, many studies have demonstrated that the pathophysiology of DFUs is especially associated with neuropeptides, inflammation, and biofilms. Neuropeptides, especially substance P (SP) and calcitonin gene-related peptide (CGRP), play an important role in wound healing. SP and CGRP accelerate the healing of cutaneous wounds by promoting neovascularization, inhibiting the release of certain proinflammatory chemokines, regulating macrophage polarization, and so on. However, the expression of SP and CGRP was downregulated in DM and DFUs. DFUs are characterized by a sustained inflammatory phase. Immune cells such as neutrophils and macrophages are involved in the sustained inflammatory phase in DFUs by extracellular traps (NETs) and dysregulated macrophage polarization, which delays wound healing. Furthermore, DFUs are at increased risk of biofilm formation. Biofilms disturb wound healing by inducing a chronic inflammatory response, inhibiting macrophage phagocytosis and keratinocyte proliferation migration, and transferring antimicrobial resistance genes. To understand the relationships among neuropeptides, inflammation, biofilms, and DFUs, this review highlights the recent scientific advances that provide possible pathophysiological insights into the delayed healing of DFUs.

Combination treatment of dendrosomal nanocurcumin and low-level laser therapy develops proliferation and migration of mouse embryonic fibroblasts and alter TGF-β, VEGF, TNF-α and IL-6 expressions involved in wound healing process

INTRODUCTION

Pressure ulcer (PU) is known as the third most costly disorder usually caused by prolonged pressure and stagnation in various parts of the body. Although several therapeutic approaches are employing, obstacles in appropriate healing for skin lesions still exist which necessitates new practical alternative or adjunctive treatments. Low level laser therapy (LLLT) as one of the mentioned new strategies have gained attention. Besides, curcumin is an herbal medicine extracted from turmeric with anti-inflammatory and antioxidative properties with promising beneficial therapeutic effects in wound healing. Employing dendrosomal nanoparticles, we overcome the hydrophobicity of curcumin in the present study. We hypothesized that combination treatment of DNC+LLLT (450 nm) simultaneously may promote the wound healing process.

MATERIAL AND METHODS

MTT assay, PI staining followed by flowcytometry, scratch assay and intracellular ROS measurement were used to investigate the effects caused by DNC and LLLT (450 nm) alone and in combination, on proliferation, cell cycle, migration and oxidative stress mouse embryonic fibroblast cells, respectively. The levels of growth factors and pro-inflammatory cytokines were evaluated by qRT-PCR and ELISA.

RESULTS

Our results indicated that combination exposure with DNC and LLLT leads to increased proliferation and migration of MEFs as well as being more efficient in significantly upregulating growth factors (TGF-β, VEGF) and decline in inflammatory cytokines (TNF-α, IL-6). Moreover, findings of this research provide persuasive support for the notion that DNC could reduce the LLLT-induced enhancement in intracellular ROS in mouse embryonic fibroblasts.

CONCLUSION

Concurrent exposure to anti-oxidant concentrations of DNC and LLLT enriched S phase entry and therefor increased proliferation as well as migration on MEFs through regulating the expression levels growth factors and shortening the inflammatory phase by modulating of cytokines. It should be noted that DNC were able to reduce the laser-induced oxidative stress, during wound healing, representing an informative accompaniment with LLLT.

Multifunctional bioactive core-shell electrospun membrane capable to terminate inflammatory cycle and promote angiogenesis in diabetic wound

Diabetic wound (DW) healing is a major clinical challenge due to multifactorial complications leading to prolonged inflammation. Electrospun nanofibrous (NF) membranes, due to special structural features, are promising biomaterials capable to promote DW healing through the delivery of active agents in a controlled manner. Herein, we report a multifunctional composite NF membrane loaded with ZnO nanoparticles (NP) and oregano essential oil (OEO), employing a new loading strategy, capable to sustainedly co-deliver bioactive agents. Physicochemical characterization revealed the successful fabrication of loaded nanofibers with strong in vitro anti-bacterial and anti-oxidant activities. Furthermore, in vivo wound healing confirmed the potential of bioactive NF membranes in epithelialization and granulation tissue formation. The angiogenesis was greatly prompted by the bioactive NF membranes through expression of vascular endothelial growth factor (VEGF). Moreover, the proposed NF membrane successfully terminated the inflammatory cycle by downregulating the pro-inflammatory cytokines interleukin −6 (IL-6) and matrix metalloproteinases-9 (MMP-9). In vitro and in vivo studies revealed the proposed NF membrane is a promising dressing material for the healing of DW.

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A modified loading strategy was employed for dual bioactive agents through electrospinning.

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The nanofibers sustainedly released the two bioactive agents.

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The fabricated bioactive membranes turned out to be biocompatible, antioxidant and antibacterial.

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The proposed bioactive membranes have posesses the potential of healing diabetic wounds.

Whether or Not the Effects of Curcuma longa Supplementation Are Associated with Physical Exercises in T1DM and T2DM: A Systematic Review

Diabetes mellitus is one of the most prevalent chronic diseases in the world; one of its main characteristics is chronic hyperglycemia. Pharmacotherapy and other alternatives such as regular exercise are among the therapeutic methods used to control this pathology and participate in glycemic control, as well as the ingestion of plant extracts with antioxidant effects. Among the different plants used for this purpose, curcumin has potential to be used to attenuate the hyperglycemic condition triggered by diabetes mellitus (DM). Some prior studies suggest that this plant has antioxidant and hypoglycemic potential. This review aims to evaluate the antioxidant and hypoglycemic potential of curcumin supplementation in Type 1 DM (T1DM) and Type 2 DM (T2DM). The search considered articles published between 2010 and 2019 in English and Portuguese, and a theoretical survey of relevant information was conducted in the main databases of scientific publications, including the Virtual Health Library and its indexed databases, PubMed, LILACS (Latin American and Caribbean Literature on Health Sciences-Health Information for Latin America and the Caribbean-BIREME/PAHO/WHO), and Scientific Electronic Library Online (SciELO). The associated use of turmeric and physical exercise has demonstrated antioxidant, anti-inflammatory, and hypoglycemic effects, suggesting that these could be used as potential therapeutic methods to improve the quality of life and survival of diabetic patients.

Curcumin inhibits lipopolysaccharide and lipoteichoic acid-induced expression of proinflammatory cytokines and production of PGE2 in the primary bubaline endometrial stromal cells

Infection of the uterus with Gram-positive Trueperella pyogenes and Gram-negative Escherichia coli is a common cause of postpartum endometritis in the cattle and buffalo and the condition is treated with antimicrobial drugs. The presence of drug residues in the milk and development of resistant bacteria necessitate the evaluation of alternate therapies for endometritis. Accordingly, we tested the immunomodulatory effect of curcumin in the bubaline endometrial stromal cells after treatment with the lipoteichoic acid (LTA) of Gram-positive Staphylococcus aureus and lipopolysaccharide (LPS) of Gram-negative E. coli that activate toll-like receptors (TLR-2 and TLR-4, respectively). Confluent primary culture of endometrial stromal cells was treated with LTA (1 µg/mL) and/or LPS (0.1 µg/mL), in the presence or absence of curcumin (30 µM for 24 h). PGE₂ was assayed in the supernatant and the relative expression of proinflammatory cytokines (PICs) (IL1B, IL6, IL8 and TNFA) transcripts were quantified using real-time PCR. LTA was not effective in stimulating PGE₂ production or upregulating the PIC expression except IL8. LTA+LPS increased PGE₂ production and upregulated IL6 and IL8 genes. Curcumin inhibited the basal and LTA+LPS induced production of PGE₂ and upregulation of PIC production. It was apparent that LPS, but not LTA, is a potent stimulator of PGE₂ from the bubaline endometrial stromal cells. Curcumin downregulated the expression of LPS and/or LTA induced PICs and PGE₂ and may be an alternate to antimicrobial drugs for the therapeutic management of endometritis.

Tibetan medicine Ru-yi-Zhen-bao Pills exhibits anti-migraine effect through mediating PAG anti-nociceptive channel

ETHNOPHARMACOLOGICAL RELEVANCE

Migraine is a disabling neurovascular disorder, which increases risk of cardiovascular events and is a social burden worldwide. The present first-line anti-migraine medications can cause overwhelming side-effects, of which one includes the onset of cardiovascular disease. As one of the marketed Tibetan drugs, Ru-yi-Zhen-bao Pills (RYZBP) have been clinically used to treat cardiovascular disorders and as anti-migraine medication. However, there is currently no research exploring the anti-migraine actions of RYZBP.

AIM OF THE STUDY

The current research was designed to assess the anti-migraine roles of RYZBP and explore the underlying mechanisms in a nitroglycerin (NTG)-induced migraine rat model trial.

MATERIALS AND METHODS

120 rats were randomly divided into the following six groups of 20 rats each: normal control group, model control group, positive control group, and RYZBP high/medium/low-dose groups (Ru-yi-Zhen-bao Pills; TH 1.00 g/kg, TM 0.50 g/kg and TL 0.25 g/kg). All rats were administered intragastrically for 7 consecutive days, which were subcutaneously injected with the NTG (10 mg/kg) after the last gavage (except in the normal control group). 3min after NTG treatment, 30 rats (5 rats from each group) were anesthetized and devoted to electroencephalogram(EEG) testing, which was used to evaluate the analgesic effect of RYZBP. One hour after NTG treatment, the rest of the 90 rats (15 rats from each group) were anesthetized and midbrain tissue sample was dissected. The dissection was then washed with physiological saline and collected. The histopathological changes in the periaqueductal gray(PAG) of 5 tissue samples were determined by aematoxylin-eosin (H&E) staining, as well as an estimation of substance P (SP) and neurokinin 1 receptor (NK1R) expression through immunohistochemically staining(IHC). Another 5 midbrain preparations were carried out to evaluate calcitonin gene-related peptide (CGRP), proenkephalin (PENK), SP, and cholecystokinin (CCK) expressions by real-time quantitative polymerase chain reaction (RT-qPCR). The rest of the 5 brainstem tissues were then used to measure CCK, CGRP, and opioid peptide receptor (DORR) levels by western blotting(WB).

RESULTS

In the EEG test, RYZBP (TM 0.50 g / kg) treatment transformed the EEG pain-wave of the NTG-induced migraine model rats in different time period. In the mechanism assay, compared with the model control group, RYZBP pretreatment reduced inflammatory cell infiltration, fibrosis and vacuolation of neuronal cells of PAG tissue seen by HE staining. IHC experiments further showed that RYZBPTM up-regulated SP expression levels and enhanced NK1R levels in the NTG-induced migraine rats (P < 0.05). Therapeutic administration of RYZBP also increased PENK mRNA expression and DORR protein level. Both RT-qPCR and western blotting trials indicated that RYZBP treatment significantly decreased CCK and CGRP expression levels (P < 0.01 or P < 0.05) in the NTG-induced migraine rats.

CONCLUSIONS

RYZBP has the potential to be an effective anti-migraine treatment through suppressing the EEG pain-wave, increasing the levels of SP, PENK, DORR and reducing expression of CCK and CGRP. Mediating the PAG anti-nociceptive channel and inhibiting central sensitization were the two potential mechanisms, which offers further evidence for clinical therapy.

Quercetin accelerated cutaneous wound healing in rats by modulation of different cytokines and growth factors

Quercetin on wounds could be favorable for healing based on its variety of biological effects. Eighty wounded rats were divided into four groups i.e. dimethyl sulfoxide, 0.03% quercetin, 0.1% quercetin, and 0.3% quercetin-treated. Different treatments were topically applied for 20 days. Quercetin (0.3%) caused the fastest wound closure and markedly improved the oxidative stress. Quercetin treatment increased the expressions of IL-10, VEGF, TGF-β₁, CD31, α-SMA, PCNA, and GAP-43, and decreased the expressions of TNF-α. Early infiltration of inflammatory cells and formation of good quality granulation tissue dominated by fibroblast proliferation, angiogenesis, and collagen deposition in quercetin treated groups was also evident. All these effects were more pronounced at 0.3% quercetin concentration. The earliest regeneration of epithelial layer was also observed in 0.3% quercetin-treated wounds. In conclusion, 0.3% quercetin accelerates wound healing efficiently by modulating antioxidant system of wound, cytokines, growth factors, other proteins and cells involved in healing.

Incorporation of ROS-Responsive Substance P-Loaded Zeolite Imidazolate Framework-8 Nanoparticles into a Ca2+-Cross-Linked Alginate/Pectin Hydrogel for Wound Dressing Applications

PURPOSE

Wound healing, especially of extensive full-thickness wounds, is one of the most difficult problems in clinical studies. In this study, we prepared a novel substance P (SP)-delivery system using zeolite imidazolate framework-8 (ZIF-8) nanoparticles.

METHODS

We synthesized ZIF-8 nanoparticles using a modified biomimetic mineralization method. We then coated SP-loaded ZIF-8 nanoparticles (SP@ZIF-8) with polyethylene glycol-thioketal (PEG-TK) to fabricate SP@ZIF-8-PEG-TK nanoparticles, and encapsulated them in injectable hydrogel composed of sodium alginate and pectin and cross-linked using calcium chloride. The final hydrogel wound dressing containing SP@ZIF-8-PEG-TK nanoparticles was called SP@ZIF-8-PEG-TK@CA.

RESULTS

The fabricated ZIF-8 nanoparticles had high SP-loading efficiency. SP-release assay showed that the SP@ZIF-8-PEG-TK nanoparticles maintained drug activity and showed responsive release under stimulation by reactive oxygen species. The SP@ZIF-8-PEG-TK nanoparticles promoted proliferation of human dermal fibroblasts, up-regulated expression levels of inflammation-related genes in macrophages, and exhibited favorable cytocompatibility in vitro. Full-thickness excision wound models in vivo confirmed that SP@ZIF-8-PEG-TK@CA dressings had excellent wound-healing efficacy by promoting an early inflammatory response and subsequent M2 macrophage polarization in the wound-healing process.

CONCLUSION

In conclusion, these findings indicated that SP@ZIF-8-PEG-TK@CA dressings might be useful for wound dressing applications in the clinic.

The analgesic hybrid of dermorphin/substance P and analog of enkephalin improve wound healing in streptozotocin-induced diabetic rats

The purpose of this study was to investigate the effect of the peptide analgesic hybrid compounds: AWL3106 analog of dermorphin and substance P (7-11), and biphalin enkephalin analog on wound healing in streptozotocin-induced diabetic rats. The diabetes was induced in 6-7 week-old male Wistar rats by intraperitoneal injection of streptozotocin. After 70 days, the wounds were created on the back of the rats and then, once a day for 21 days, the dressing containing lanolin ointment, 10% of keratin scaffolds, and 1 mM of AWL3106 or biphalin was applied. The wounds histology were analyzed by hematoxylin and eosin staining. The orientation and organization of collagen was analyzed by Masson's trichome staining. The number of macrophages, blood vessels, and fibroblasts were visualized by CD68, CD34, and vimentin immunoreactivity, respectively. Our results demonstrated that the wound area of AWL3106- and biphalin-treated groups was greatly reduced (up to 47% on the 7 day) in comparison with untreated diabetic groups. The immunohistochemical staining of macrophages demonstrated that AWL3106 and biphalin accelerated inflammatory progression and subsequently decreased persistent inflammation. The histological analysis showed that the structure of tissue in the groups under the study was very similar to the one of wound tissue in N-DM group. The H&E and Masson's trichome staining demonstrated that the orientation and organization of collagen as well as the number and shape of blood vessels were better in 3106- and BIF-treated group than in DM group. In conclusion, the obtained data suggested that our hybrid peptides enhanced wound healing, particularly by accelerating the inflammatory phase and promoted the wound closure.

A ZnO-curcumin nanocomposite embedded hybrid collagen scaffold for effective scarless skin regeneration in acute burn injury

Scar formation in severe burn injury is a major health concern. Herein, we developed a hybrid collagen scaffold with an incorporated ZnO-curcumin nanocomposite, which facilitates scarless wound healing. Biocompatibility and hemocompatibility studies unveiled that the hybrid scaffold is apt for in vivo wound healing studies. Histological and immunohistochemical analyses demonstrate that the hybrid scaffold accelerated scarless burn wound healing in albino rats owing to the ZnO-curcumin nanocomposite induced up-regulation of angiogenesis and TGF-β3 expression. The semi-quantitatively measured scar elevation index of the hybrid scaffold-treated animals is on a par with that of the unwounded or normal skin. The studies suggest that the prepared hybrid biomaterial could be a potential candidate for scarless healing in severe burn injuries.

Immunomodulatory effect of curcumin on lipopolysaccharide- and/or flagellin-induced production of prostaglandin E2 and relative expression of proinflammatory cytokines in the primary bubaline endometrial stromal cells

Developing alternate therapies for bovine endometritis is important in the context of drug residues in the milk and emergence of antimicrobial resistant bacteria. In this regard, we studied the immunomodulatory effect of curcumin 30 µM, on lipopolysaccharide- (LPS) and/or flagellin (100 ng/ml each)-induced prostaglandin E₂ (PGE₂ ) and proinflammatory cytokines (PIC) using primary bubaline endometrial stromal cells. After 24 hr treatment, the supernatant was assayed for PGE₂ while cells were used for relative quantification of cytokines like IL-1β, IL-6, IL-8 and TNF α transcripts using a control group as calibrator. LPS was found to possess potent stimulatory effect on PGE₂ production, whereas the flagellin was not as potent as LPS in stimulating the PGE₂ production either per se or in combination with LPS. LPS markedly up-regulated the transcripts of IL-8 and IL-6 as compared to IL-1β and TNF α in the bubaline endometrial stromal cells. Except for IL-8, flagellin did not up-regulate other PICs. There was no additive effect between LPS and flagellin on the up-regulation of inflammatory cytokines. Curcumin inhibited the LPS-induced up-regulation of PIC with strong down-regulation of IL-8. The inhibitory effects of curcumin on the inflammatory mediators suggest a potential in the treatment of bovine endometritis.

Systemic administration of curcumin or piperine enhances the periodontal repair: a preliminary study in rats

OBJECTIVES

Studies have documented the anti-inflammatory effects of spices, which may be related to treatment of chronic diseases. The purpose of this study was to evaluate the influence of curcumin and piperine and their association on experimental periodontal repair in rats.

MATERIALS AND METHODS

Periodontitis was induced via the installation of a ligature around the first molar. After 15 days, the ligatures were removed, and the rats were separated into groups (12 animals per group): (i) curcumin, (ii) piperine, (iii) curcumin+piperine, (iv) corn oil vehicle, and (v) control group (animals had ligature-induced periodontitis but were not treated). The compounds were administered daily, for 15 days by oral gavage. Animals were euthanized at 5 and 15 days, and hemimaxillae and gingival tissues were harvested. Bone repair was assessed by μCT (microcomputer tomography). Histological sections were stained with hematoxylin/eosin (H/E) for the assessment of cellular infiltrate or picrosirius red for quantification of collagen content, and subjected to immunohistochemistry for detecting NF-ĸB. Gingival tissues were used to evaluate levels of TGF-β and IL-10 (ELISA).

RESULTS

Curcumin and piperine increased the TGF-β level, significantly improved the collagen repair, and decreased the cellularity and activation of NF-ĸB in the periodontal tissues, but only curcumin caused a significant increase in early bone repair.

CONCLUSION

Curcumin and piperine promoted a substantive effect on tissue repair; however, there was not synergistic effect of compounds administered in combination.

CLINICAL RELEVANCE

Curcumin and piperine stimulates the tissue repair and may be potential candidates for the treatment of periodontal disease.

Effects of curcumin on hypoxia-inducible factor as a new therapeutic target

Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that consists of two subunits, the HIF-1α and HIF-1β (ARNT). Under hypoxic conditions, HIF-1 is an adaptive system that regulates the transcription of multiple genes associated with growth, angiogenesis, proliferation, glucose transport, metabolism, pH regulation and cell death. However, aberrant HIF-1 activation contributes to the pathophysiology of several human diseases such as cancer, ischemic cardiovascular disorders, and pulmonary and kidney diseases. A growing body of evidence indicates that curcumin, a natural bioactive compound of turmeric root, significantly targets both HIF-1 subunits, but is more potent against HIF-1α. In this review, we have summarized the knowledge about the pharmacological effects of curcumin on HIF-1 and the related molecular mechanisms that may be effective candidates for the development of multi-targeted therapy for several human diseases.

A Chitosan-Based Liposome Formulation Enhances the In Vitro Wound Healing Efficacy of Substance P Neuropeptide

Currently, there is considerable interest in developing innovative biodegradable nanoformulations for controlled administration of therapeutic proteins and peptides. Substance P (SP) is a neuropeptide of 11 amino acids that belongs to the tachykinins family and it plays an important role in wound healing. However, SP is easily degradable in vivo and has a very short half-life, so the use of chitosan-based nanocarriers could enhance its pharmaceutical properties. In light of the above, the aim of this work was to produce and characterize chitosan-coated liposomes loaded with SP (SP-CH-LP) as novel biomaterials with potential application in mucosal wound healing. The loaded system’s biophysical properties were characterized by dynamic light scattering with non-invasive back scattering (DLS-NIBS), mixed mode measurements and phase analysis light scattering (M3-PALS) and high performance liquid chromatography with ultraviolet/visible light detection (HPLC-UV/VIS). Then, the efficacy of the obtained nanoformulations was examined via proof-of-principle experiments using in vitro cell assays. These assays showed an increment on cell motility and proliferation after treatment with free and encapsulated neuropeptides. Additionally, the effect of SP on wound healing was enhanced by the entrapment on CH-LP. Overall, the amenability of chitosan-based nanomaterials to encapsulate peptides and proteins constitutes a promising approach towards potential novel therapies to treat difficult wounds.