Potential Role of Curcumin Against Biofilm-Producing Organisms on the Skin: A Review

Effectiveness of Ya-Samarn-Phlae in diabetic wound healing: Evidence from in vitro studies and a multicenter randomized controlled clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Ya-Samarn-Phlae (YaSP) has traditionally been widely used in southern Thailand for treating chronic and infected wounds, including diabetic foot ulcers. However, there are only a limited number of clinical studies supporting the use of this polyherbal formulation. Therefore, the present work aims to provide clinical evidence to support the application of YaSP, prepared according to a standardized traditional procedure (T-YaSP). Additionally, its potential chemical markers and wound healing-related biological activities were examined.

MATERIALS AND METHODS

The in vitro wound healing-related biological activities of YaSP ethanol extract and T-YaSP, including antibacterial activity against Staphylococcus epidermidis, inhibition and eradication of staphylococcal biofilm, anti-inflammatory effects, and enhancement of human dermal fibroblast migration in scratch wounds, were examined using well-established protocols. The chemical profiles of the ethanol extract of YaSP and T-YaSP were compared, and with promising chemical markers, arecoline, alpha-mangostin, and curcumin were selected and quantified using the HPLC method. A prospective, multicenter, randomized, controlled, parallel-group study was conducted over 12 weeks to evaluate the efficacy of the YaSP solution as an adjunct therapy, combined with standard wound care, for diabetic ulcers compared to standard treatment.

RESULTS

The YaSP extract reduces NO production and can scavenge NO radicals in LPS-induced RAW 264.7 macrophage cells. Additionally, in a scratch assay, this extract and one of its herbal components, Curcuma longa, enhance the migration of human dermal fibroblasts. T-YaSP, containing 2.412 ± 0.002 mg/g of arecoline, 2.399 ± 0.005 mg/g of curcumin, and 0.017 ± 0.000 mg/g of α-mangostin, has shown the ability to inhibit the development and eradicate the mature biofilm of S. epidermidis. The use of T-YaSP as an adjunct therapy led to a significantly higher proportion of patients achieving healing within six weeks compared to the standard treatment group (36%/9 patients vs. 4%/1 patient; p = 0.013). After 12 weeks, 19 out of 25 patients in the T-YaSP group experienced complete healing, whereas only four patients in the standard treatment group achieved complete wound healing (76% in the T-YaSP group vs. 16% in the control group; p < 0.001).

CONCLUSION

The results presented here represent the first randomized controlled trial to demonstrate the effectiveness of the traditional polyherbal solution, T-YaSP, which exhibits a wide range of wound healing-related activities. Utilizing T-YaSP as an adjunctive treatment resulted in a significant improvement in the number of type 2 diabetic patients achieving complete healing. However, to explore and utilize YaSP further, conducting a double-blind, randomized controlled trial with a larger population is necessary.

Antibacterial Activity of Thesium chinense Turcz Extract Against Bacteria Associated with Upper Respiratory Tract Infections

Purpose

The drug resistance of Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae has become more and more serious, and it is urgent to seek new antibacterial drugs. In this study, Thesium chinense Turcz. extracts were tested for its potential antibacterial activities.

Methods

T. chinense powder was extracted with 5 solvents of different polarity (ethyl alcohol, petroleum ether, ethyl acetate, n-butyl alcohol and double distilled water), and their antibacterial activities were tested. The Broth dilution method was used to evaluate the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of highly active plant extracts with a concentration of 1g/mL. The inhibitory activity of this extract on biofilm formation was investigated. Afterwards, we investigated its effect on the transcriptome of S. aureus.

Results

The ethanol extract coded as BRY, only inhibited S. aureus, whereas the ethyl acetate extract coded as BY2 showed inhibitory effect on all the tested bacteria. The MIC of BRY on S. aureus was 128 mg/mL, and the MBC was 512 mg/mL. The MIC of BY2 against S. aureus, S. pneumoniae, S. pyogenes and H. influenzae were 8 mg/mL, 4 mg/mL, 4 mg/mL, and 4 mg/mL, respectively. The MBC of BY2 for these four bacteria ranged from 4 to 256 mg/mL. Mechanism studies have shown that BRY and BY2 have an impact on anti-formation of biofilms at MIC concentrations. Transcriptome sequencing results showed that 531 genes were up-regulated and 340 genes showed down-regulated expression in S. aureus after BY2 treatment.

Conclusion

BY2 has a broader antibacterial spectrum than BRY. Meanwhile, the inhibitory effect of BY2 on S. aureus is better than BRY. The mechanism of BY2 against S. aureus may relate to its inhibition of ribosome synthesis, restriction of key enzymes of citric acid cycle, decrease of pathogenicity and influence on biofilm formation. The results confirmed that BY2 was the main antibacterial part of T. chinense, which can be used as a source of antibacterial agents.

Effect of curcumin nanoparticles and alcoholic extract of Falcaria vulgaris on the growth rate, biofilm, and gene expression in Pseudomonas aeruginosa isolated from burn wound infection

PURPOSE

This study aimed to investigate the effect of Curcumin nanoparticles and alcoholic extract of Falcaria vulgaris on the growth rate, biofilm, and gene expression in Pseudomonas aeruginosa isolated from burn wound infection.

METHODS

The alcoholic extract of Falcaria vulgaris was purchased from Pasargad Company. Curcumin nanoparticles were synthesized. Antibacterial activity of Curcumin nanoparticles and alcoholic extract of Falcaria vulgaris was investigated by microdilution method alone and in combination. Biofilm inhibitory was investigated by microtitrplate method. Effect of Curcumin nanoparticles and alcoholic extract of Falcaria vulgaris were evaluated on algD gene expression via Real-Time PCR. Cytotoxicity was evaluated by MTT assay on HDF cell line. Then, the data were analyzed using SPSS software.

RESULTS

Synthesized Curcumin nanoparticles were approved by Fourier Transform Infrared (FTIR), and Scanning Electron Microscope. The alcoholic extract of Falcaria Vulgaris showed significant antibacterial activity against multidrug resistance (MDR) P. aeruginosa isolates at a concentration of 156.25 µg/mL. Moreover, MIC of the curcumin nanoparticle for isolates was 625 µg/mL. Based on fraction inhibition concentration, synergy, and the additive effect were shown against %7.7, and %93.3 of MDRs, respectively. The sub-MIC concentration of the binary compound reduced biofilms and algD gene expression in P. aeruginosa isolates. The Biological function of HDF cell lines was desirable after the effect of the binary compound.

CONCLUSIONS

Regarding our results, this combination can be suggested as a promising agent in terms of biofilm inhibitory and antimicrobial properties.

Acetyl Zingerone: A Photostable Multifunctional Skincare Ingredient That Combats Features of Intrinsic and Extrinsic Skin Aging

The cumulative damage skin sustains from exposure to environmental stressors throughout life exerts significant effects on skin aging and cancer development. One of the main ways by which environmental stressors mediate their effects within skin is through induction of reactive oxygen species (ROS). In this review, we chronicle the multiple properties by which acetyl zingerone (AZ) as a skincare ingredient can benefit skin (1) by helping manage overproduction of ROS through multiple routes as an antioxidant, physical quencher and selective chelator, (2) by fortifying protection after UV exposure ends to prevent the type of epidermal DNA damage that correlates with development of skin cancer, (3) by modulating matrisome activity and nurturing the integrity of the extracellular matrix (ECM) within the dermis and (4) through its proficient ability to neutralize singlet oxygen, by stabilizing the ascorbic acid precursor tetrahexyldecyl ascorbate (THDC) in the dermal microenvironment. This activity improves THDC bioavailability and may blunt pro-inflammatory effects of THDC, such as activation of type I interferon signaling. Moreover, AZ is photostable and can sustain its properties during UV exposure, in contrast to α-tocopherol. All these properties of AZ translate into measurable clinical benefits to improve the visual appearance of photoaged facial skin and to strengthen the skin's own defenses against sun damage.

Porous Silicon Carrier Endowed with Photothermal and Therapeutic Effects for Synergistic Wound Disinfection

Drug carriers endowed with photothermal effects will allow the drug delivery system to release drugs in a thermal-stimuli manner. In addition, the photothermal therapy (PTT) will also interplay with therapeutic drugs loaded in the carrier to exhibit synergistic bioactivity for various disease treatment. However, endowing the drug carrier with photothermal and synergistic therapeutic effects still has challenge. Herein, we demonstrate that surface modification of porous silicon (PSi) with polydopamine (PDA) could endow the classical drug carrier with a significant photothermal effect for advanced antibacterial therapy and wound disinfection. Specifically, the PSi surface interacts with a Cu²⁺/PDA complex via a simple and fast surface reduction-induced deposition method, forming the unique CuPDA coated PSi microcarrier (CuPPSi) without blocking the mesoporous structure. The CuPPSi carrier generates a higher near-infrared (NIR) photothermal efficiency and improved drug loading capacity owing to the abundant functional groups of PDA. Stimuli-responsive release of antibacterial Cu²⁺ and loaded curcumin (Cur) from CuPPSi can be realized under multiple stimuli including pH, reactive oxygen species and NIR laser irradition. Benefited from the carrier's intrinsic multimodal therapy, the CuPPSi-Cur platform exhibits amplified, broad-spectrum, and synergistic antibacterial effect, killing more than 98% for both Staphylococcus aureus and Escherichia coli at a mild PTT temperature (∼45 °C). Notably, the combined therapy promotes migration of fibroblasts with no significant cytotoxicity as revealed through cell experiments in vitro. In bacteria-infected mice model, efficient bacterial ablation and wound healing are further demonstrated with negligible side effects in vivo. Overall, the rational design of a drug carrier with photothermal and therapeutic effects provides a novel intervention for amplifing wound disinfection clinically.

Using Caenorhabditis elegans to Model Therapeutic Interventions of Neurodegenerative Diseases Targeting Microbe-Host Interactions

Emerging evidence from both clinical studies and animal models indicates the importance of the interaction between the gut microbiome and the brain in the pathogenesis of neurodegenerative diseases (NDs). Although how microbes modulate neurodegeneration is still mostly unclear, recent studies have started to probe into the mechanisms for the communication between microbes and hosts in NDs. In this review, we highlight the advantages of using Caenorhabditis elegans (C. elegans) to disentangle the microbe-host interaction that regulates neurodegeneration. We summarize the microbial pro- and anti-neurodegenerative factors identified using the C. elegans ND models and the effects of many are confirmed in mouse models. Specifically, we focused on the role of bacterial amyloid proteins, such as curli, in promoting proteotoxicity and neurodegeneration by cross-seeding the aggregation of endogenous ND-related proteins, such as α-synuclein. Targeting bacterial amyloid production may serve as a novel therapeutic strategy for treating NDs, and several compounds, such as epigallocatechin-3-gallate (EGCG), were shown to suppress neurodegeneration at least partly by inhibiting curli production. Because bacterial amyloid fibrils contribute to biofilm formation, inhibition of amyloid production often leads to the disruption of biofilms. Interestingly, from a list of 59 compounds that showed neuroprotective effects in C. elegans and mouse ND models, we found that about half of them are known to inhibit bacterial growth or biofilm formation, suggesting a strong correlation between the neuroprotective and antibiofilm activities. Whether these potential therapeutics indeed protect neurons from proteotoxicity by inhibiting the cross-seeding between bacterial and human amyloid proteins awaits further investigations. Finally, we propose to screen the long list of antibiofilm agents, both FDA-approved drugs and novel compounds, for their neuroprotective effects and develop new pharmaceuticals that target the gut microbiome for the treatment of NDs. To this end, the C. elegans ND models can serve as a platform for fast, high-throughput, and low-cost drug screens that target the microbe-host interaction in NDs.

Gelatin/Chitosan Films Incorporated with Curcumin Based on Photodynamic Inactivation Technology for Antibacterial Food Packaging

Photodynamic inactivation (PDI) is a new type of non-thermal sterilization technology that combines visible light with photosensitizers to generate a bioactive effect against foodborne pathogenic bacteria. In the present investigation, gelatin (GEL)/chitosan (CS)-based functional films with PDI potency were prepared by incorporating curcumin (Cur) as a photosensitizer. The properties of GEL/CS/Cur (0.025, 0.05, 0.1, 0.2 mmol/L) films were investigated by evaluating the surface morphology, chemical structure, light transmittance, and mechanical properties, as well as the photochemical and thermal stability. The results showed a strong interaction and good compatibility between the molecules present in the GEL/CS/Cur films. The addition of Cur improved different film characteristics, including thickness, mechanical properties, and solubility. More importantly, when Cur was present at a concentration of 0.1 mM, the curcumin-mediated PDI inactivated >4.5 Log CFU/mL (>99.99%) of Listeria monocytogenes, Escherichia coli, and Shewanella putrefaciens after 70 min (15.96 J/cm2) of irradiation with blue LED (455 ± 5) nm. Moreover, Listeria monocytogenes and Shewanella putrefaciens were completely inactivated after 70 min of light exposure when the Cur concentration was 0.2 mM. In contrast, the highest inactivation effect was observed in Vibrio parahaemolyticus. This study showed that the inclusion of Cur in the biopolymer-based film transport system in combination with photodynamic activation represents a promising option for the preparation of food packaging films.

Promising Natural Products in New Drug Design, Development, and Therapy for Skin Disorders: An Overview of Scientific Evidence and Understanding Their Mechanism of Action

The skin is the largest organ in the human body, composed of the epidermis and the dermis. It provides protection and acts as a barrier against external menaces like allergens, chemicals, systemic toxicity, and infectious organisms. Skin disorders like cancer, dermatitis, psoriasis, wounds, skin aging, acne, and skin infection occur frequently and can impact human life. According to a growing body of evidence, several studies have reported that natural products have the potential for treating skin disorders. Building on this information, this review provides brief information about the action of the most important in vitro and in vivo research on the use of ten selected natural products in inflammatory, neoplastic, and infectious skin disorders and their mechanisms that have been reported to date. The related studies and articles were searched from several databases, including PubMed, Google, Google Scholar, and ScienceDirect. Ten natural products that have been reported widely on skin disorders were reviewed in this study, with most showing anti-inflammatory, antioxidant, anti-microbial, and anti-cancer effects as the main therapeutic actions. Overall, most of the natural products reported in this review can reduce and suppress inflammatory markers, like tumor necrosis factor-alpha (TNF-α), scavenge reactive oxygen species (ROS), induce cancer cell death through apoptosis, and prevent bacteria, fungal, and virus infections indicating their potentials. This review also highlighted the challenges and opportunities of natural products in transdermal/topical delivery systems and their safety considerations for skin disorders. Our findings indicated that natural products might be a low-cost, well-tolerated, and safe treatment for skin diseases. However, a larger number of clinical trials are required to validate these findings. Natural products in combination with modern drugs, as well as the development of novel delivery mechanisms, represent a very promising area for future drug discovery of these natural leads against skin disorders.

Exploring Phenolic Compounds as Quorum Sensing Inhibitors in Foodborne Bacteria

The emergence of multidrug-resistant bacteria stimulates the search for new substitutes to traditional antimicrobial agents, especially molecules with antivirulence properties, such as those that interfere with quorum sensing (QS). This study aimed to evaluate the potential of phenolic compounds for QS inhibition in a QS biosensor strain (Chromobacterium violaceum) and three foodborne bacterial species (Aeromonas hydrophila, Salmonella enterica serovar Montevideo, and Serratia marcescens). Initially, an in silico molecular docking study was performed to select the compounds with the greatest potential for QS inhibition, using structural variants of the CviR QS regulator of C. violaceum as target. Curcumin, capsaicin, resveratrol, gallic acid, and phloridizin presented good affinity to at least four CviR structural variants. These phenolic compounds were tested for antimicrobial activity, inhibition of biofilm formation, and anti-QS activity. The antimicrobial activity when combined with kanamycin was also assessed. Curcumin, capsaicin, and resveratrol inhibited up to 50% of violacein production by C. violaceum. Biofilm formation was inhibited by resveratrol up to 80% in A. hydrophila, by capsaicin and curcumin up to 40% in S. Montevideo and by resveratrol and capsaicin up to 60% in S. marcescens. Curcumin completely inhibited swarming motility in S. marcescens. Additionally, curcumin and resveratrol increased the sensitivity of the tested bacteria to kanamycin. These results indicate that curcumin and resveratrol at concentrations as low as 6μM are potential quorum sensing inhibitors besides having antimicrobial properties at higher concentrations, encouraging applications in the food and pharmaceutical industries.

Ag-Based Synergistic Antimicrobial Composites. A Critical Review

The emerging problem of the antibiotic resistance development and the consequences that the health, food and other sectors face stimulate researchers to find safe and effective alternative methods to fight antimicrobial resistance (AMR) and biofilm formation. One of the most promising and efficient groups of materials known for robust antimicrobial performance is noble metal nanoparticles. Notably, silver nanoparticles (AgNPs) have been already widely investigated and applied as antimicrobial agents. However, it has been proposed to create synergistic composites, because pathogens can find their way to develop resistance against metal nanophases; therefore, it could be important to strengthen and secure their antipathogen potency. These complex materials are comprised of individual components with intrinsic antimicrobial action against a wide range of pathogens. One part consists of inorganic AgNPs, and the other, of active organic molecules with pronounced germicidal effects: both phases complement each other, and the effect might just be the sum of the individual effects, or it can be reinforced by the simultaneous application. Many organic molecules have been proposed as potential candidates and successfully united with inorganic counterparts: polysaccharides, with chitosan being the most used component; phenols and organic acids; and peptides and other agents of animal and synthetic origin. In this review, we overview the available literature and critically discuss the findings, including the mechanisms of action, efficacy and application of the silver-based synergistic antimicrobial composites. Hence, we provide a structured summary of the current state of the research direction and give an opinion on perspectives on the development of hybrid Ag-based nanoantimicrobials (NAMs).

Oral nano-curcumin on gingival inflammation in patients with gingivitis and mild periodontitis

Gingivitis can trigger gingival diseases such as periodontitis. Since the complete removal of microbial plaques by mechanical procedures is not conceivable in some conditions and also chemical mouthwashes have a lot of side effects, finding a new treatment strategy would be useful. In the present study, for the first time, the effects of oral nano-curcumin on gingival inflammation in patients with gingivitis and mild periodontitis were assessed. Forty eight patients with gingivitis and mild periodontitis participated in this clinical trial. In one group the patients were treated with Sina curcumin capsules 80 mg and the other group received a placebo. Clinical parameters, including modified gingival index, papillary bleeding index, and plaque index were determined on days 0, 7, 14, and 28. There were no significant differences in age, sex, papillary bleeding index (PBI), and modified gingival index (MGI) between the two groups at baseline. There was a dropout of two patients (both from the placebo group). The MGI and PBI have a significantly decreasing trend in both case and control groups and the decreases were severe in the case group. The differences between PBI and MGI in the two groups were significant at 14 and 28 days. The plaque index did not significantly change in either group over the study period. The trend of changes in plaque index was not different between the two groups of the study. In the current study, no side effect was found in the patients. Oral nano-curcumin has positive effects on the decrease of inflammation and gingival bleeding in patients with gingivitis and mild periodontitis. Nano-curcumin capsules have a systemic target site with more bioavailability than topical forms.

In vivo Antibacterial Activity of Star Anise (Illicium verum Hook.) Extract Using Murine MRSA Skin Infection Model in Relation to Its Metabolite Profile

Introduction

Star anise fruits (Illicium verum Hook.) have been used as an important treatment in traditional Chinese medicine. The previous studies reported the activity of the non-polar fractions as potential sources of antibacterial metabolites, and little was done concerning the polar fractions of star anise.

Methods

The antibacterial activity of the star anise aqueous methanolic (50%) extract against multidrug-resistant Acinetobacter baumannii AB5057 and methicillin-resistant Staphylococcus aureus (MRSA USA300) was investigated in vitro (disc diffusion assay, minimum bactericidal concentration determination, anti-biofilm activity and biofilm detachment activity). The antibacterial activity was further tested in vivo using a murine model of MRSA skin infection. Ultra-performance liquid chromatography coupled to high-resolution mass spectrometry (UPLC/HRMS) approach was applied for the identification of the metabolites responsible for the antibacterial activity. The antioxidant potential was evaluated using five in vitro assays: TAC (total antioxidant capacity), DPPH, ABTS, FRAP (ferric reducing antioxidant power) and iron-reducing power.

Results

In vitro, star anise aqueous methanolic extract showed significant inhibition and detachment activity against biofilm formation by the multidrug-resistant and highly virulent Acinetobacter baumannii AB5057 and MRSA USA300. The topical application of the extract in vivo significantly reduced the bacterial load in MRSA-infected skin lesions. The extract showed strong antioxidant activity using five different complementary methods. More than seventy metabolites from different classes were identified: phenolic acids, phenylpropanoids, sesquiterpenes, tannins, lignans and flavonoids.

Conclusion

This study proposes the potential use of star anise polar fraction in anti-virulence strategies against persistent infections and for the treatment of staphylococcal skin infections as a topical antimicrobial agent. To our knowledge, our research is the first to provide the complete polar metabolome list of star anise in an approach to understand the relationship between the chemistry of these metabolites and the proposed antibacterial activity.

Investigating the Effect of Nano-Curcumin on the Expression of Biofilm Regulatory Genes of Pseudomonas aeruginosa

BACKGROUND

Pseudomonas aeruginosa is an opportunistic pathogen that causes serious nosocomial infections, especially in immunodeficient patients and cystic fibrosis, cancer, and burned individuals. The biofilm that plays an important role in the virulence of P. aeruginosa is under the regulation of quorum sensing and two-component regulatory systems of bacteria. Curcumin, an active phenolic extract of turmeric has shown an inhibitory effect on the biofilm formation of some pathogenic bacteria. Thus, the present study aims to evaluate the effect of Nano-Curcumin on the expression of major regulatory genes involved in biofilm formation of P. aeruginosa.

MATERIALS AND METHODS

The biofilm formation of P. aeruginosa ATCC 10145 was assessed in the presence of 15, 20, and 25 µg/mL concentrations of Nano-Curcumin using the microplate titer method. The effect of Nano-Curcumin on the expression level of regulatory genes were determined by relative reverse transcriptase-realtime PCR.

RESULTS

In the absence of Nano-Curcumin, P. aeruginosa strain ATCC 10145 strongly produced biofilm (3+) and in the presence of 15 and 20 µg/mL, biofilm formation was reduced to moderate (2+) and weak biofilm producer (1+), respectively. Nano-Curcumin at a concentration of 25µg/mL inhibited biofilm formation in P. aeruginosa. The expression of regulatory genes was not affected by biofilm inhibitory concentrations of Nano-Curcumin.

CONCLUSION

The antibiofilm mechanism of Curcumin is not related to the downregulation of regulatory systems of P. aeruginosa and probably it prevents the formation of a complete biofilm structure.

Formulation of More Efficacious Curcumin Delivery Systems Using Colloid Science: Enhanced Solubility, Stability, and Bioavailability

Curcumin is a bioactive constituent isolated from turmeric that has historically been used as a seasoning, pigment, and herbal medicine in food. Recently, it has become one of the most commonly studied nutraceuticals in the pharmaceutical, supplement, and food areas because of its myriad of potential health benefits. For instance, it is claimed to exhibit antioxidant, anti-inflammatory, antimicrobial, antiparasite, and anticancer activities when ingested as a drug, supplement, or food. Toxicity studies suggest that it is safe to consume, even at relatively high levels. Its broad-spectrum biological activities and low toxicity have meant that it has been widely explored as a nutraceutical ingredient for application in functional foods. However, there are several hurdles that formulators must overcome when incorporating curcumin into commercial products, such as its low water solubility (especially under acidic and neutral conditions), chemical instability (especially under neutral and alkaline conditions), rapid metabolism by enzymes in the human body, and limited bioavailability. As a result, only a small fraction of ingested curcumin is actually absorbed into the bloodstream. These hurdles can be at least partially overcome by using encapsulation technologies, which involve trapping the curcumin within small particles. Some of the most commonly used edible microparticles or nanoparticles utilized for this purpose are micelles, liposomes, emulsions, solid lipid particles, and biopolymer particles. Each of these encapsulation technologies has its own benefits and limitations for particular product applications and it is important to select the most appropriate one.

Reinforcement of Polycaprolactone/Chitosan with Nanoclay and Controlled Release of Curcumin for Wound Dressing

A novel clay-reinforced polycaprolactone/chitosan/curcumin (PCl/CS/Clay/Cur) composite film was fabricated in this study. The prepared Cur-loading composite films were characterized with attenuated total reflection Fourier transformed infrared spectroscopy, scanning electron microscopy, atomic force microscopy, water contact angle, differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction, and the results showed good dispersion of clay in the composite films. The addition of nanoclay was found to significantly increase the tensile strength. Also, the clay-enhanced drug-loading films exhibited better controlled-release profiles of Cur than those membranes without clay. Skin disinfection test demonstrated that the curcumin-loaded film could protect wound from bacterial infection. Cytotoxicity analysis proved the good biocompatibility of the composite films. The clay-enhanced Cur-loading films might be promising candidates for wound care.

Therapeutic effects of curcumin on sepsis and mechanisms of action: A systematic review of preclinical studies

Sepsis is a complex disease that begins with an infectious disorder and causes excessive immune responses. Curcumin is considered as an active component of turmeric that can improve the condition in sepsis due to its anti-inflammatory and antioxidant properties. PubMed, Embase, Google Scholar, Web of Science, and Scopus databases were searched. Searching was not limited to a specific publication period. Only English-language original articles, which had examined the effect of curcumin on sepsis, were included. At first, 1,098 articles were totally found, and 209 articles were selected after excluding duplicated data; 46 articles were remained due to the curcumin effects on sepsis. These included 23 in vitro studies and 23 animal studies. Our results showed that curcumin and various analogs of curcumin can have an inhibitory effect on sepsis-induced complications. Curcumin has the ability to inhibit the inflammatory, oxidative coagulation factors, and regulation of immune responses in sepsis. Despite the promising evidence of the therapeutic effects of curcumin on the sepsis complication, further studies seem necessary to investigate its effect and possible mechanisms of action in human studies.

Antimicrobial Potential of Single Metabolites of Curcuma longa Assessed in the Total Extract by Thin-Layer Chromatography-Based Bioautography and Image Analysis

Curcuma longa from Zingiberaceae belongs to the major spices consumed around the world, known from its cholagogue, anti-inflammatory, and antimicrobial properties. Lack of data on the activity of single components of turmeric extract encouraged the authors to apply TLC (thin-layer chromatography) based bioautography studies to reveal its antimicrobial constituents and construct a universal platform for the bioactivity assessment of crude extracts, with help of a freeware ImageJ software. This optimized chromatographic bioassay performed on diethyl ether and methanol extracts of Curcuma longa was successfully applied on the total extract and revealed the antimicrobial potential of single components against a variety of Gram-positive strains, with no need for their isolation from the mixture. The obtained results were further confronted with a classic microdilution antimicrobial assay on the isolates, purified from the crude extracts by centrifugal partition chromatography in the following solvent system: heptane-chloroform-methanol-water (5:6:3:2) (v/v/v/v).

Curcumin promotes burn wound healing in mice by upregulating caveolin-1 in epidermal stem cells

We aimed to explore the effect of curcumin on epidermal stem cells (ESCs) in regulating wound healing and the underlying molecular mechanism. We treated mouse ESCs isolated from skin tissues with curcumin, and then assessed the proliferation ability of cells induced by epidermal growth factor using cell counting kit-8 assay. The pluripotency of ESCs was evaluated as well through examination of Nanog expression in ESCs. Further, mice with skin burns were treated with ESCs with or without curcumin pretreatments. Histological evaluations were then preformed to determine wound scores, cell proliferation, reepithelialization, and capillary density in wounds. Curcumin treatment promoted the proliferative ability of ESCs and conditioned medium from curcumin-treated ESCs enhanced human umbilical vein endothelial cell (HUVEC) tube formation. We also found curcumin treatment elevated caveolin-1 expression in ESCs, which was required for the beneficial effect of curcumin on ESC proliferation and HUVEC tube formation. Next, using a mouse model of burn wound healing, curcumin-treated ESCs exhibited enhanced wound closure, which also required caveolin-1 expression. Our current study demonstrates the beneficial effect of curcumin on burn wound healing in mice, which is mediated by upregulating caveolin-1 in ESCs, and supports the potential therapeutic role of curcumin in ESC-based treatment against skin wound healing.

Antibacterial and antioxidant activities for natural and synthetic dual-active compounds

Antimicrobial resistance is widely recognized as a grave threat to global health in the 21st century, since the past decades have seen a dramatic increase in human-pathogenic bacteria that are resistant to one or multiple antibiotics. New antimicrobial agents are urgently required, particularly in the treatment of chronic infections such as cystic fibrosis, often associated with persistent colonization by drug-resistant pathogens and epithelial damage by pulmonary oxidative stress. In such events, it would be favourable to find agents that could have antioxidant and antibacterial activities combined in one molecule. The discovery of compounds that can show a dual-target activity considerably increased in the last years, reflecting the growing confidence that this new approach could lead to better therapeutic solutions for complex multigenic diseases. The aim of this review is to report those natural and synthetic compounds displaying significant antioxidant and antibacterial activities. In recent years there has been a growing attention on plant-derived antimicrobials as an alternative to antibiotics, for their efficacy and low tendency in developing bacterial resistance. Moreover, it was found that some natural products could enhance the activity of common antibiotics displaying a synergistic effect. We then report some selected synthetic compounds with an in-built capacity to act on two targets or with the combination in a single structure of two pharmacophores with antioxidant and antibacterial activities. Recent literature instances were screened and the most promising examples of dual-active antibacterial-antioxidant molecules were highlighted.

Oral administration of powdered dried rhizomes of Curcuma longa L. (turmeric, Zingiberaceae) is effective in the treatment of doxorubicin-induced kidney injury in rats

Curcumin is a polyphenol present in the rhizomes of the species Curcuma longa L. ("turmeric," Zingiberaceae), which has been used for centuries as an anti-inflammatory. We aimed to evaluate the anti-inflammatory effects of C. longa in renal injury induced by doxorubicin (DOX, 3.5 mg.kg^-1 IV). We studied four groups of Wistar rats: two groups with DOX-induced kidney injury, one fed with standard food and another with standard food mixed with C. longa (5 mg.g^-1 ). Two other control groups without kidney injury were fed with the same foods. We measured albuminuria, body weight, and food intake every 2 weeks. After 8 weeks, treatment with C. longa did not change albuminuria, but it significantly attenuated the excretion of urinary inflammatory markers monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-β (TGF-β) and significantly attenuated immunostaining for desmin, vimentin, and ED-1⁺ cells in renal tissues of rats with DOX-induced kidney injury. In addition, treatment with C. longa resulted in significantly lower glomerular and tubule interstitial injury scores, compared with that in the DOX-STD group. In conclusion, administration of powdered rhizomes of C. longa for 8 weeks to rats with DOX-induced kidney injury did not reduce albuminuria but led to a significant decrease in urinary inflammatory markers MCP-1 and TGF-β and decreased histopathological alterations and immunostaining for desmin, vimentin, and ED-1⁺ cells kidneys tissues.

Curcumin sensitized the antitumour effects of irradiation in promoting apoptosis of oesophageal squamous-cell carcinoma through NF-κB signalling pathway

Objectives

To investigate the potential synergistic effect of curcumin with irradiation (IR) in oesophageal squamous-cell carcinoma (ESCC) and elucidate the underlying molecular mechanisms.

Methods

The ESCC cell lines were established from clinical samples. Cell apoptosis post-treatment was stained by Annexin V/PI staining and analysed by flow cytometry. Cells survived IR was evaluated with clonogenic assay. Xenograft tumour model was established by subcutaneous inoculation, and tumour progression was monitored. The NF-κB pathway was characterized by immunoblotting.

Key findings

Curcumin enhanced the pro-apoptotic effect of IR in ESCC cells. Pretreatment with curcumin significantly sensitized ESCC cells to IR in a dose-dependent manner. Coadministration with curcumin remarkably extended the median survival time of ESCC xenograft mice while exposed to IR therapy. The xenograft tumour progression was significantly suppressed as well. Mechanistically, curcumin treatment was demonstrated to efficiently inhibited NF-κB signalling.

Conclusions

We have well-recapitulated the pathological properties and therapeutic response of ESCC with established cell lines derived from clinical samples. We further demonstrated the significantly synergistic effect of curcumin on IR-elicited cell apoptosis in ESCC both in vitro and in vivo. Our data suggested the potential therapeutic values of curcumin for future clinical investigations.