Antibacterial Mechanism of Curcumin: A Review

Trimethoprim-Based multicomponent solid Systems: Mechanochemical Screening, characterization and antibacterial activity assessment

In this work, multicomponent trimethoprim-based pharmaceutical solid systems were developed by mechanochemistry, using coformers from the GRAS list and other active pharmaceutical ingredients. The choice of coformers took into account their potential to increase the aqueous solubility/dissolution rate of TMP or its antibacterial activity. All the binary systems were characterized by thermal analysis, powder X-ray diffraction and infrared spectroscopy, and 3 equimolar systems with FTIR pointing to salts, and 4 eutectic mixtures were identified. The intrinsic dissolution rate of TMP in combination with nicotinic acid (a salt) and with paracetamol (eutectic mixture) were 25% and 5% higher than for pure TMP, respectively. For both Gram-positive and -negative strains, the antibacterial activity of TMP with some of the coformers was improved, since the dosage used was lower than the TMP control. A significant increase in antibacterial activity against E. coli was found for the eutectic mixture with curcumin, with the best results being obtained for the eutectic and equimolar mixtures with ciprofloxacin. Combining trimethoprim with coformers offers an interesting alternative to using trimethoprim alone: multicomponent forms with enhanced TMP dissolution rates were identified, as well as combinations showing enhanced antibacterial activity relatively to the pure drug.

A multifunctional nanoplatform for precision-guided therapeutic intervention in bacterial infection

Skin wound infection has become a global clinical problem in recent years. Curcumin (Cur) and polylysine (PLL) are natural products with strong antibacterial properties. However, the poor water solubility and low stability of Cur and the cationic toxicity of PLL limit their application. In this study, we synthesized a macromolecular hyaluronic acid (HA)-curcumin drug (HC) via esterification. HC was attracted by electrostatic interactions with positively charged PLL to form a spherical nanocomplex (HCP) with hyaluronidase (HAase) and pH dual response under ultrasonication. HCP was found to target the bacterial infection microenvironment and release Cur and PLL for synergistic antibacterial action. In addition, HCP was proven to exhibit good biocompatibility and broad spectrum antibacterial activity to bacterial strains S. aureus and E. coli and antibacterial biofilm activities in vitro. In vivo experiments showed that HCP could inhibit pathogens and promote wound healing. These results prove that HCP can be used as a new strategy for the treatment and management of infected wounds.

The Bright Side of Curcumin: A Narrative Review of Its Therapeutic Potential in Cancer Management

Curcumin, a polyphenolic compound derived from Curcuma longa, exhibits significant therapeutic potential in cancer management. This review explores curcumin's mechanisms of action, the challenges related to its bioavailability, and its enhancement through modern technology and approaches. Curcumin demonstrates strong antioxidant and anti-inflammatory properties, contributing to its ability to neutralize free radicals and inhibit inflammatory mediators. Its anticancer effects are mediated by inducing apoptosis, inhibiting cell proliferation, and interfering with tumor growth pathways in various colon, pancreatic, and breast cancers. However, its clinical application is limited by its poor bioavailability due to its rapid metabolism and low absorption. Novel delivery systems, such as curcumin-loaded hydrogels and nanoparticles, have shown promise in improving curcumin bioavailability and therapeutic efficacy. Additionally, photodynamic therapy has emerged as a complementary approach, where light exposure enhances curcumin's anticancer effects by modulating molecular pathways crucial for tumor cell growth and survival. Studies highlight that combining low concentrations of curcumin with visible light irradiation significantly boosts its antitumor efficacy compared to curcumin alone. The interaction of curcumin with cytochromes or drug transporters may play a crucial role in altering the pharmacokinetics of conventional medications, which necessitates careful consideration in clinical settings. Future research should focus on optimizing delivery mechanisms and understanding curcumin's pharmacokinetics to fully harness its therapeutic potential in cancer treatment.

Chitosan-Integrated Curcumin-Graphene Oxide/Copper Oxide Hybrid Nanocomposites for Antibacterial and Cytotoxicity Applications

This study deals with the facile synthesis of a single-pot chemical technique for chitosan-curcumin (CUR)-based hybrid nanocomposites with nanostructured graphene oxide (GO) and copper oxide (CuO) as the antibacterial and cytotoxic drugs. The physicochemical properties of synthesized hybrid nanocomposites such as CS-GO, CS-CuO, CS-CUR-GO, and CS-CUR-GO/CuO were confirmed with various advanced tools. Moreover, the in vitro drug release profile of the CS-CUR-GO/CuO nanocomposite exhibited sustained and controlled release during different time intervals. Also, the antibacterial activity of the CS-CUR-GO/CuO hybrid nanocomposite presented the maximum bactericidal effect against Staphylococcus aureus and Escherichia coli pathogens. The hybrid nanocomposites revealed improved cytotoxicity behaviour against cultured mouse fibroblast cells (L929) via cell adhesion, DNA damage, and proliferation. Thus, the chitosan-based hybrid nanocomposites offer rich surface area, biocompatibility, high oxidative stress, and bacterial cell disruption functionalities as a potential candidate for antibacterial and cytotoxicity applications.

Curcumin inhibits growth of Porphyromonas gingivalis by arrest of bacterial dipeptidyl peptidase activity

Background

Curcumin is a multi-functional polyphenol with anti-bacterial and anti-inflammatory effects and may have potential for treatment of periodontal diseases. The present study was conducted to examine the molecular basis of the anti-bacterial effect of curcumin against Porphyromonas gingivalis using metabolome analysis.

Materials and Methods

P. gingivalis were incubated with 10 µg/mL curcumin, and then metabolites were analyzed with CE-TOF/MS. Expression levels of sigma factors were also evaluated using RT-PCR assays. The activities of dipeptidyl peptidases (DPPs) were assessed by examining the degradation reactions of MCA-labeled peptides.

Results

The relative amounts of various glycogenic amino acids were significantly decreased when P. gingivalis was incubated with curcumin. Furthermore, the metabolites on the amino acid degradation pathway, including high-energy compounds such as ATP, various intermediate metabolites of RNA/DNA synthesis, nucleoside sugars and amino sugars were also decreased. Additionally, the expression levels of sigma-54 and sigma-70 were significantly decreased, and the same results as noted following nutrient starvation. Curcumin also significantly suppressed the activities of some DPPs, while the human DPP-4 inhibitors markedly inhibited the growth of P. gingivalis and activities of the DPPs.

Conclusions

Curcumin suppresses the growth of P. gingivalis by inhibiting DPPs and also interferes with nucleic acid synthesis and central metabolic pathways, beginning with amino acid metabolism.

Curcumin Nanocapsules based on carbon dots for photodynamic sterilization towards Listeria monocytogenes and Staphylococcus aureus

Curcumin (Cur) as a natural food additive and photosensitizer has been widely applied on photodynamic sterilization and preservation for food, but the poor aqueous solubility and light stability restrict its extensive application. In this study, we report a Cur nanocapsules (Cur-CDs) made by carbon dots (CDs). Attributing to the hydrogen bonds formed between Cur and CDs, Cur-CDs exhibits excellent Cur aqueous solubility each to 9286.98 ng/mL (enhanced by 246.27 times) and light stability (enhanced by 1.51 times). The photogenerated electron transmission from Cur to CDs in addition resulted in >1.23 and 1.60 times generation of •O2- and •OH, compared to that of bare Cur. Accordingly, 5.73 × 103 CFU L. monocytogenes, and 5.43 × 103 CFU S. aureus were killed by 0.06 mg/mL Cur-CDs within 20 mins of blue light, showing the promising potential in the development and application of safe and environmentally friendly non-thermal sterilization technology based on Cur-CDs.

N-Hydroxyalkanamide Based Organo/hydrogels as Novel Scaffolds for pH-Dependent Metronidazole and Theophylline Release

The traditional delivery of metronidazole and theophylline presents challenges like bitter taste, variable absorption, and side effects. However, gel-based systems offer advantages including enhanced targeted drug delivery, minimized side effects, and improved patient compliance, effectively addressing these challenges. Consequently, a cost-effective synthesis of N-hydroxyalkanamide gelators with varying alkyl chain lengths was achieved in a single-step reaction procedure. These gelators formed self-assembled aggregates in DMSO/water solvent system, resulting in organo/hydrogels at a minimum gelation concentration of 1.5 % w/v. Subsequently, metronidazole and theophylline were encapsulated within the gel core and released through gel-to-sol transition triggered by pH variation at 37 °C, while maintaining the structural-activity relationship. UV-vis spectroscopy was employed to observe the drug release behavior. Furthermore, in vitro cytotoxicity assays revealed cytotoxic effects against A549 lung adenocarcinoma cells, indicating anti-proliferative activity against human lung cancer cells. Specifically, the gel containing theophylline (16HAD+Th) exhibited cytotoxicity on cancerous A549 cells with IC50 values of 19.23±0.6 μg/mL, followed by the gel containing metronidazole (16HAD+Mz) with IC50 values of 23.75±0.7 μg/mL. Moreover, the system demonstrated comparable antibacterial activity against both gram-negative (E. coli) and gram-positive bacteria (S. aureus).

Engineered Robust Hydrophobic/Hydrophilic Nanofibrous Scaffolds with Drug-Eluting, Antioxidant, and Antimicrobial Capacity

Multifunctional nanofibrous architectures have attracted extensive attention for biomedical applications due to their adjustable and versatile properties. Electrospun fabrics stand out as key building blocks for these structures, yet improving their mechanobiological and physicochemical performance is a challenge. Here, we introduce biodegradable engineered hydrophobic/hydrophilic scaffolds consisting of electrospun polylactide nanofibers coated with drug-eluting synthetic (poly(vinyl alcohol)) and natural (starch) polymers. The microstructure of these composite scaffolds was tailored for an increased hydrophilicity, optimized permeability, water retention capacity of up to 5.1 g/g, and enhanced mechanical properties under both dry and wet conditions. Regarding the latter, normalized tensile strengths of up to 32.4 MPa were achieved thanks to the improved fiber interactions and fiber-coating stress transfer. Curcumin was employed as a model drug, and its sustained release in a pure aqueous medium was investigated for 35 days. An in-depth study of the release kinetics revealed the outstanding water solubility and bioavailability of curcumin, owing to its complexation with the hydrophilic polymers and further delineated the role of the hydrophobic nanofibrous network in regulating its release rate. The modified curcumin endowed the composites with antioxidant activities up to 5.7 times higher than that of free curcumin as well as promising anti-inflammatory and bacteriostatic activities. The cytocompatibility and cell proliferation capability on human dermal fibroblasts also evidenced the safe use of the constructs. Finally, the fabrics present pH-responsive color-changing behavior easily distinguishable within the pH range of 5-9. Thus, these designs offer a facile and cost-effective roadmap for the fabrication of smart multifunctional biomaterials, especially for chronic wound healing.

Dietary Curcumin Intake and Its Effects on the Transcriptome and Metabolome of Drosophila melanogaster

Curcumin, a polyphenol derived from Curcuma longa, used as a dietary spice, has garnered attention for its therapeutic potential, including antioxidant, anti-inflammatory, and antimicrobial properties. Despite its known benefits, the precise mechanisms underlying curcumin's effects on consumers remain unclear. To address this gap, we employed the genetic model Drosophila melanogaster and leveraged two omics tools-transcriptomics and metabolomics. Our investigation revealed alterations in 1043 genes and 73 metabolites upon supplementing curcumin into the diet. Notably, we observed genetic modulation in pathways related to antioxidants, carbohydrates, and lipids, as well as genes associated with gustatory perception and reproductive processes. Metabolites implicated in carbohydrate metabolism, amino acid biosynthesis, and biomarkers linked to the prevention of neurodegenerative diseases such as schizophrenia, Alzheimer's, and aging were also identified. The study highlighted a strong correlation between the curcumin diet, antioxidant mechanisms, and amino acid metabolism. Conversely, a lower correlation was observed between carbohydrate metabolism and cholesterol biosynthesis. This research highlights the impact of curcumin on the diet, influencing perception, fertility, and molecular wellness. Furthermore, it directs future studies toward a more focused exploration of the specific effects of curcumin consumption.

Turmeric and curcumin as adjuncts in controlling Helicobacter pylori-associated diseases: a narrative review

Non-antibiotic adjuncts may improve Helicobacter pylori infection control. Our aim was to emphasize curcumin benefits in controlling H. pylori infection. We discussed publications in English mostly published since 2020 using keyword search. Curcumin is the main bioactive substance in turmeric. Curcumin inhibited H. pylori growth, urease activity, three cag genes, and biofilms through dose- and strain-dependent activities. Curcumin also displayed numerous anticancer activities such as apoptosis induction, anti-inflammatory and anti-angiogenic effects, caspase-3 upregulation, Bax protein enhancement, p53 gene activation, and chemosensitization. Supplementing triple regimens, the agent increased H. pylori eradication success in three Iranian studies. Bioavailability was improved by liposomal preparations, lipid conjugates, electrospray-encapsulation, and nano-complexation with proteins. The agent was safe at doses of 0.5->4 g daily, the most common (in 16% of the users) adverse effect being gastrointestinal upset. Notably, curcumin favorably influences the intestinal microbiota and inhibits Clostridioides difficile. Previous reports showed the inhibitory effect of curcumin on H pylori growth. Curcumin may become an additive in the therapy of H. pylori infection, an adjunct for gastric cancer control, and an agent beneficial to the intestinal microbiota. Further examination is necessary to determine its optimal dosage, synergy with antibiotics, supplementation to various eradication regimens, and prophylactic potential.

Preparation, structural characterization, and functional attributes of zein-lysozyme-κ-carrageenan ternary nanocomposites for curcumin encapsulation

The low water solubility and inadequate bioavailability of curcumin significantly hinder its broad biological applications in the realms of food and medicine. There is limited information currently available regarding the particle characteristics and functional capabilities of zein-lysozyme-based nanomaterials. Thereby, the primary goal of the current work is to effectively develop innovative zein-lysozyme-κ-carrageenan complex nanocomposites (ZLKC) as a reliable carrier for curcumin encapsulation. As a result, ZLKC nanoparticles showed a smooth spherical nanostructure with improved encapsulation efficiency. Fourier-transform infrared, fluorescence spectroscopy, dissociation assay, and circular dichroism analysis revealed that hydrophobic and electrostatic interactions and hydrogen bonding were pivotal in the construction and durability of these composites. X-ray diffraction examination affirmed the lack of crystallinity in curcumin encapsulated within nanoparticles. The incorporation of κ-carrageenan significantly improved the physicochemical stability of ZLKC nanoparticles in diverse environmental settings. Additionally, ZLKC nanocomposites demonstrated enhanced antioxidant and antimicrobial properties, as well as sustained release characteristics. Therefore, these findings demonstrate the potential application of ZLKC nanocomposites as delivery materials for encapsulating bioactive substances.

Curcumin as a natural potential drug candidate against important zoonotic viruses and prions: A narrative review

Zoonotic diseases are major public health concerns and undeniable threats to human health. Among Zoonotic diseases, zoonotic viruses and prions are much more difficult to eradicate, as they result in higher infections and mortality rates. Several investigations have shown curcumin, the active ingredient of turmeric, to have wide spectrum properties such as anti-microbial, anti-vascular, anti-inflammatory, anti-tumor, anti-neoplastic, anti-oxidant, and immune system modulator properties. In the present study, we performed a comprehensive review of existing in silico, in vitro, and in vivo evidence on the antiviral (54 important zoonotic viruses) and anti-prion properties of curcumin and curcuminoids in PubMed, Google Scholar, Science Direct, Scopus, and Web of Science databases. Database searches yielded 13,380 results, out of which 216 studies were eligible according to inclusion criteria. Of 216 studies, 135 (62.5%), 24 (11.1%), and 19 (8.8%) were conducted on the effect of curcumin and curcuminoids against SARS-CoV-2, Influenza A virus, and dengue virus, respectively. This review suggests curcumin and curcuminoids as promising therapeutic agents against a wide range of viral zoonoses by targeting different proteins and signaling pathways.

Yolk-shelled silver nanowire@amorphous metal-organic framework for controlled drug delivery and light-promoting infected wound healing

Bacteria-infected wounds healing has been greatly hindered by antibiotic resistance and persistent inflammation. It is crucial to develop multifunctional nanocomposites that possess effective antibacterial properties and can simultaneously accelerate the wound healing process to overcome the above challenges. Herein, we prepared a yolk-shell structured Ag nanowires (NWs)@amorphous hollow ZIF-67 by etching ZIF-67 onto the Ag NWs for infected wound healing for the first time. The etched hollow structure of amorphous ZIF-67 in the nanocomposite makes it a promising platform for loading healing-promoting drugs. We extensively studied the antibacterial and healing-promoting properties of the curcumin (CCM)-loaded nanocomposite (Ag NWs@C-HZ67). Ag NWs, being noble metal materials with plasmonic effects, can absorb a broad range of natural light and convert it to thermal energy. This photothermal conversion further improves the release of antibacterial components and wound healing drugs when exposed to light. During the healing process of an infected wound, Ag and Co ions were released from Ag NWs@C-HZ67 upon direct contact with the wound exudate and under the influence of light irradiation. Simultaneously, the loaded CCM leaked out to repair the infected wound. The minimum inhibitory concentrations of the Ag NWs@C-HZ67 groups against Escherichia coli and Staphylococcus aureus bacteria decreased to 3 and 3 μg ml-1 when exposed to white light. Furthermore, an in vivo assessment of infected wound healing demonstrated that combining Ag NWs@C-HZ67 with light significantly accelerated the wound healing process, achieving 70% healing by the 6th day and almost complete healing by the 8th day. This advanced nanocomposite, consisting of components that possess antibacterial and growth-promoting properties, offers a safe, effective and clinically-translatable solution for accelerating the healing process of infected wounds.

Exploring new avenues of health protection: plant-derived nanovesicles reshape microbial communities

Symbiotic microbial communities are crucial for human health, and dysbiosis is associated with various diseases. Plant-derived nanovesicles (PDNVs) have a lipid bilayer structure and contain lipids, metabolites, proteins, and RNA. They offer unique advantages in regulating microbial community homeostasis and treating diseases related to dysbiosis compared to traditional drugs. On the one hand, lipids on PDNVs serve as the primary substances that mediate specific recognition and uptake by bacteria. On the other hand, due to the multifactorial nature of PDNVs, they have the potential to enhance growth and survival of beneficial bacterial while simultaneously reducing the pathogenicity of harmful bacteria. In addition, PDNVs have the capacity to modulate bacterial metabolism, thus facilitating the establishment of a harmonious microbial equilibrium and promoting stability within the microbiota. These remarkable attributes make PDNVs a promising therapeutic approach for various conditions, including periodontitis, inflammatory bowel disease, and skin infection diseases. However, challenges such as consistency, isolation methods, and storage need to be addressed before clinical application. This review aims to explore the value of PDNVs in regulating microbial community homeostasis and provide recommendations for their use as novel therapeutic agents for health protection.

Advancements in Dermatological Applications of Curcumin: Clinical Efficacy and Mechanistic Insights in the Management of Skin Disorders

Curcumin, derived from Curcuma longa (turmeric), exhibits significant potential in dermatology, addressing conditions like atopic dermatitis, psoriasis, chronic wounds, skin cancer, and infections through its anti-inflammatory, antioxidant, anticancer, and antimicrobial properties. This review synthesizes evidence on curcumin's mechanisms, including modulation of immune responses and promotion of wound healing, showcasing its efficacy in reducing inflammation, cytokine levels, and enhancing skin barrier functions. Studies highlight curcumin's ability to selectively target tumor cells, suggesting a multifaceted approach to cancer therapy with minimal side effects. Despite promising therapeutic benefits, challenges remain in bioavailability, potency, and targeted delivery, underscoring the need for further research to optimize dosages, delivery methods, and assess long-term safety. The integration of curcumin into dermatological practice requires a balanced consideration of evidence-based efficacy and safety. Curcumin's comprehensive utility in dermatology, coupled with the necessity for advanced scientific exploration, emphasizes the importance of combining traditional knowledge with contemporary research to improve patient care in dermatology. This approach could significantly enhance outcomes for individuals with skin-related conditions, marking curcumin as a versatile and promising agent in the field.

Novel Functional Dressing Materials for Intraoral Wound Care

Intraoral wounds represent a particularly challenging category of mucosal and hard tissue injuries, characterized by the unique structures, complex environment, and distinctive healing processes within the oral cavity. They have a common occurrence yet frequently inflict significant inconvenience and pain on patients, causing a serious decline in the quality of life. A variety of novel functional dressings specifically designed for the moist and dynamic oral environment have been developed and realized accelerated and improved wound healing. Thoroughly analyzing and summarizing these materials is of paramount importance in enhancing the understanding and proficiently managing intraoral wounds. In this review, the particular processes and unique characteristics of intraoral wound healing are firstly described. Up-to-date knowledge of various forms, properties, and applications of existing products are then intensively discussed, which are categorized into animal products, plant extracts, natural polymers, and synthetic products. To conclude, this review presents a comprehensive framework of currently available functional intraoral wound dressings, with an aim to provoke inspiration of future studies to design more convenient and versatile materials.

Curcuma Longa: Nutraceutical Use and Association With Nanotechnology

Curcumin is a natural product found in the rhizome of Curcuma longa (L.) and other Curcuma spp. As a lipophilic molecule, it has greater affinity for polar, non-polar, alkaline, or extremely acidic organic solvents. Several studies indicate that curcumin has several benefits for human health, for example, against degenerative diseases, cancer, and infectious diseases. To obtain a quality product with nutraceutical properties, it is necessary to know its physicochemical characteristics and preserve it from cultivation until ingestion by the human. However, its low solubility leads to low absorption; in this context, nanotechnological systems can contribute to increase curcumin bioavailability. This review aims to highlight important issues in all stages that curcumin goes through: from aspects related to its extraction to its association with nanotechnology. Although curcumin extraction process is already well established, it is possible to observe more and more research focused on increasing yield and being more environmentally friendly. Further, curcumin's low absorption is notable due to its physicochemical characteristics, mainly due to its low aqueous solubility. However, its association with nanotechnology shows to be promising and an increasingly growing trend because the use of this "Indian solid gold" is the hope of many patients.

A novel acid-responsive polymer coating with antibacterial and antifouling properties for the prevention of biofilm-associated infections

Chronic infections caused by the pathogenic biofilms on implantable medical devices pose an increasing challenge. To combat long-term biofilm-associated infections, we developed a novel dual-functional polymer coating with antibacterial and antifouling properties. The coating consists of N-vinylpyrrolidone (NVP) and 3-(acrylamido)phenylboronic acid (APBA) copolymer brushes, which bind to curcumin (Cur) as antibacterial molecules through acid-responsive boronate ester bonds. In this surface design, the hydrophilic poly (N-vinylpyrrolidone) (PVP) component improved antifouling performance and effectively prevented bacterial adhesion and aggregation during the initial phases. The poly (3-(acrylamido) phenylboronic acid) (PAPBA, abbreviated PB) component provided binding sites for Cur by forming acid-responsive boronate ester bonds. When fewer bacteria overcame the anti-adhesion barrier and colonized, the surface responded to the decreased microenvironmental pH by breaking the boronate ester bonds and releasing curcumin. This responsive mechanism enabled Cur to interfere with biofilm formation and provide a multilayer anti-biofilm protection system. The coating showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus, preventing biofilm formation for up to 7 days. The coating also inhibited protein adsorption and platelet adhesion significantly. This coating also exhibited high biocompatibility with animal erythrocytes and pre-osteoblasts. This research offers a promising approach for developing novel smart anti-biofilm coating materials.

Effective antibacterial agents in modern wound dressings: a review

Wound infections are a significant concern in healthcare, leading to long healing times. Traditional approaches for managing wound infections rely heavily on systemic antibiotics, which are associated with the emergence of antibiotic-resistant bacteria. Therefore, the development of alternative antibacterial materials for wound care has gained considerable attention. In today's world, new generations of wound dressing are commonly used to heal wounds. These new dressings keep the wound and the area around it moist to improve wound healing. However, this moist environment can also foster an environment that is favorable for the growth of bacteria. Excessive antibiotic use poses a significant threat to human health and causes bacterial resistance, so new-generation wound dressings must be designed and developed to reduce the risk of infection. Wound dressings using antimicrobial compounds minimize wound bacterial colonization, making them the best way to avoid open wound infection. We aim to provide readers with a comprehensive understanding of the latest advancements in antibacterial materials for wound management.

Polydopamine-curcumin coating of titanium for remarkable antibacterial activity via synergistic photodynamic and photothermal properties

Combined photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a novel and effective antibacterial strategy. In order to endow titanium (Ti) with antibacterial properties, the Ti-PDA-Cur composite was prepared using the excellent adhesion properties of polydopamine (PDA) to load curcumin (Cur) on the surface of Ti. The Ti-PDA-Cur coating can produce singlet oxygen (1O2) and heat under 405 + 808 nm light irradiation, which can effectively kill Staphylococcus aureus and Escherichia coli. Moreover, the cytotoxicity and hemolysis rate of Ti-PDA-Cur were low, indicating its good biocompatibility. Therefore, this study provided a new strategy for the development of new Ti implants.

Unveiling the Potential of Natural Compounds: A Comprehensive Review on Adipose Thermogenesis Modulation

The process of adipocyte browning has recently emerged as a novel therapeutic target for combating obesity and obesity-related diseases. Non-shivering thermogenesis is the process of biological heat production in mammals and is primarily mediated via brown adipose tissue (BAT). The recruitment and activation of BAT can be induced through chemical drugs and nutrients, with subsequent beneficial health effects through the utilization of carbohydrates and fats to generate heat to maintain body temperature. However, since potent drugs may show adverse side effects, nutritional or natural substances could be safe and effective as potential adipocyte browning agents. This review aims to provide an extensive overview of the natural food compounds that have been shown to activate brown adipocytes in humans, animals, and in cultured cells. In addition, some key genetic and molecular targets and the mechanisms of action of these natural compounds reported to have therapeutic potential to combat obesity are discussed.

Photostabilities and anti-tumor effects of curcumin and curcumin-loaded polydopamine nanoparticles

Currently, the photostability of photosensitizer curcumin is the main bottleneck limiting their application, reducing the bioavailability of curcumin. Studying the effect of different light sources on the photostabilities of curcumin and loading it onto polydopamine nanocarriers with better biocompatibility will help improve its light utilization efficiency. In this study, we investigated the photostabilities of curcumin and a polydopamine-based nanoparticle (polydopamine-curcumin composite nanoparticles, PDA-Cur NPs) loaded with curcumin through in vitro and in vivo experiments to achieve better antitumor effects. The results demonstrated that curcumin has good photostability in dark, but with significant photodegradation rates in both red and blue light. Blue light has a faster effect on the photodegradation of curcumin, with a degradation rate of 42.1% after 10 minutes, which is about 1.7 times that of the red light. Our study successfully synthesized PDA-Cur NPs, demonstrating its ability to stably load and release curcumin, with a loading percentage of 65.7% after 2 hours and 41.9% release in 8 hours (pH 6.0). Compared with single curcumin treatments, the photodegradation rates of PDA-Cur NPs in red and blue light treatments were reduced by 46% and 50%, respectively. Meanwhile, PDA-Cur NPs exhibited remarkable antitumor efficacy due to PDT and promote apoptosis in cancer cells, which both better than that of single curcumin treatments. Moreover, in MCF-7 tumor-bearing mice, the PDA-Cur NPs led to significant tumor growth inhibition effects, without causing evident systemic damage in vivo. The findings highlight the potential of PDA-Cur NPs as anticancer photosensitizer with greatly increased utilization of curcumin in PDT.

Antivirulence Effects of Trans-Resveratrol and Curcumin on Methicillin-Resistant Staphylococcus aureus (MRSA) from Saudi Arabia

Methicillin-resistant Staphylococcus aureus (MRSA) is a common resistant bacterium, whose resistance has expanded to commonly used antibiotics. It is crucial to create novel treatments to tackle bacterial resistance. Trans-resveratrol and curcumin are naturally occurring phenolic compounds, whose effects on MRSA virulence are the subject of this investigation. Sub-MICs of trans-resveratrol and curcumin were tested on the virulence factors of 50 MRSA clinical isolates (CIs), including biofilm, hemolysin, hemagglutination, protease, and lecithinase. The distribution of the virulence factors of the CIs was as follows: hemolysin: 98%, hemagglutination: 70%, protease: 62%, biofilm: 56%, and lecithinase: 52%. The sub-MIC that could reduce the effect of the tested virulence factors by 50% or more (IC50) was observed in the strains that showed susceptibility to the individual administration of trans-resveratrol at 50 µg/mL and curcumin at 20 µg/mL. Hemagglutination and hemolysin activity were inhibited by at least 50% in the majority of CIs (57-94%). Meanwhile, the IC50 for protease and biofilm was observed in 6.5-17.8% of the CIs. A few of the CIs were susceptible to lecithinase inhibition, but all showed a full inhibition. This research supports the possibility of the use of these compounds to reduce the bacterial virulence that can reduce antibiotic utilization, and eventually, they can become a potential alternative treatment in combating bacterial resistance.

Advancing Gastrointestinal Health: Curcumin's Efficacy and Nanopreparations

Curcumin (CCM) is a polyphenol compound extracted from the turmeric rhizome. It has various biological activities, including antibacterial, anti-inflammatory, anti-cancer, and antioxidant. Due to its diverse activities, it is often used by researchers to study the therapeutic effects on various diseases. However, its poor solubility leads to poor bioavailability, and it is necessary to increase the water solubility with the help of carriers to improve the therapeutic effect. Gastrointestinal disease is a major global health problem that continues to affect human health. In this review, we have summarized the possible mechanism and therapeutic effect of CCM in various gastrointestinal diseases, and the improvement in the curative effect of CCM with nanopreparation. Finally, we concluded that there have been many clinical trials of CCM in combination with other drugs for the treatment of gastrointestinal disease, but so far, few have used CCM nanomaterials for treatment. Although in vitro and preclinical experiments have shown that nanopreparations can improve the efficacy of CCM, there are still insufficient studies on the safety of carriers.

A Study of the Synergistic Effects of Essential Oils from Origanum compactum and Origanum elongatum with Commercial Antibiotics against Highly Prioritized Multidrug-Resistant Bacteria for the World Health Organization

The irrational use of antibiotics has favored the emergence of resistant bacteria, posing a serious threat to global health. To counteract antibiotic resistance, this research seeks to identify novel antimicrobials derived from essential oils that operate through several mechanisms. It aims to evaluate the quality and composition of essential oils from Origanum compactum and Origanum elongatum; test their antimicrobial activity against various strains; explore their synergies with commercial antibiotics; predict the efficacy, toxicity, and stability of compounds; and understand their molecular interactions through docking and dynamic simulations. The essential oils were extracted via hydrodistillation from the flowering tops of oregano in the Middle Atlas Mountains in Morocco. Gas chromatography combined with mass spectrometry (GC-MS) was used to examine their composition. Nine common antibiotics were chosen and tested alone or in combination with essential oils to discover synergistic effects against clinically important and resistant bacterial strains. A comprehensive in silico study was conducted, involving molecular docking and molecular dynamics simulations (MD). O. elongatum oil includes borneol (8.58%), p-cymene (42.56%), thymol (28.43%), and carvacrol (30.89%), whereas O. compactum oil is mostly composed of γ-terpinene (22.89%), p-cymene (15.84%), thymol (10.21%), and (E)-caryophyllene (3.63%). With O. compactum proving to be the most potent, these essential oils showed antibacterial action against both Gram-positive and Gram-negative bacteria. Certain antibiotics, including ciprofloxacin, ceftriaxone, amoxicillin, and ampicillin, have been shown to elicit synergistic effects. To fight resistant bacteria, the essential oils of O. compactum and O. elongatum, particularly those high in thymol and (E)-caryophyllene, seem promising when combined with antibiotics. These synergistic effects could result from their ability to target the same bacterial proteins or facilitate access to target sites, as suggested by molecular docking simulations. Molecular dynamics simulations validated the stability of the examined protein-ligand complexes, emphasizing the propensity of substances like thymol and (E)-caryophyllene for particular target proteins, opening the door to potentially effective new therapeutic approaches against pathogens resistant to multiple drugs.

Visible light-activated curcumin-doped zinc oxide nanoparticles integrated into orthodontic adhesive on Micro-tensile bond strength, degree of conversion, and antibacterial effectiveness against Staphylococcus Aureus. An investigation using scanning electron microscopy and energy-dispersive X-ray spectroscopy

AIM

To acquire a thorough comprehension of the photoactivated Cur-doped ZnONPs at different concentrations 0%, 2.5%, and 5% on the physical qualities, antibacterial efficacy, degree of conversion, and μshear bond strength between orthodontic brackets and the enamel surface.

MATERIAL AND METHODS

An extensive investigation was carried out utilizing a range of analytical methods, scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FTIR) spectroscopy, micro tensile bond strength (μTBS) testing, and evaluation of antibacterial effectiveness. Cur-doped ZnONPs at concentrations of 2.5% and 5% were blended with Transbond XT, a light-curable orthodontic adhesive. A control group without the addition of Cur-doped ZnONPs was also prepared. The tooth samples were categorized into three groups based on the weight percentage of NPs: Group 1 (control) with 0% Cur-doped ZnONPs, Group 2 with 2.5 wt% Cur-doped ZnONPs, and Group 3 with 5 wt% Cur-doped ZnONPs. The SEM technique was employed to analyze the morphological characteristics of Cur-doped ZnONPs and ZnONPs. The composition and elemental distribution of the modified Cur-doped ZnONPs were assessed using energy-dispersive X-ray spectroscopy. The effectiveness of NPs at various concentrations against S.Mutans was gauged through the pour plate method. DC of Cur-doped ZnONPs at a region of 1608 cm-1 to 1636 cm-1 for the cured area, whereas the uncured area spanned the same range of 1608 cm-1 to 1636 cm-1 was assessed. The Adhesive Remnant Index (ARI) approach was utilized to investigate the bond failure of orthodontic brackets, while a Universal Testing Machine (UTM) was utilized to test μTBS. The Kruskal-Wallis test was employed to investigate variations in S.mutans survival rates. To determine the μTBS values, analysis of variance (ANOVA) and the post hoc Tukey multiple comparisons test were used.

RESULTS

The maximum μTBS was given and documented in group 3: 5 wt% Cur-doped ZnONPs (21.21 ± 1.53 MPa). The lowest μTBS was given in group 2: 2.5 wt% Cur-doped ZnONPs (19.58 ± 1.27 MPa). The highest efficacy against S.mutans was documented in group 3 in which 5 wt% Cur-doped ZnONPs (0.39 ± 0.15). The lowest efficacy was seen in group 1 in which no Cur-doped ZnONPs were used (6.47 ± 1.23). The ARI analysis indicated that the predominant failure was between scores 0 and 1 among all experimental groups. Control group 1 which was not modified showed the highest DC (73.11 ± 4.19).

CONCLUSION

Orthodontic adhesive, containing 5% Cur-doped ZnONPs photoactivated with visible light exhibited a favorable impact on μTBS and indicated enhanced antibacterial efficacy against S.mutans. Nevertheless, it was observed that the addition of Cur-doped ZnONPs at different concentrations (2.5%,5%) resulted in a decrease in the monomer-to-polymer ratio compromising DC.

Hyaluronic acid-decorated curcumin-based coordination nanomedicine for enhancing the infected diabetic wound healing

Persistent over-oxidation, inflammation and bacterial infection are the primary reasons for impaired wound repairing in diabetic patients. Therefore, crucial strategies to promote diabetic wound repairing involve suppressing the inflammatory response, inhibiting bacterial growth and decreasing reactive oxygen species (ROS) within the wound. In this work, we develop a multifunctional nanomedicine (HA@Cur/Cu) designed to facilitate the repairing process of diabetic wound. The findings demonstrated that the synthesized infinite coordination polymers (ICPs) was effective in enhancing the bioavailability of curcumin and improving the controlled drug release at the site of inflammation. Furthermore, in vitro and in vivo evaluation validate the capacity of HA@Cur/Cu to inhibit bacterial growth and remove excess ROS and inflammatory mediators, thereby significantly promoting the healing of diabetic wound in mice. These compelling findings strongly demonstrate the enormous promise of this multifunctional nanomedicine for the treatment of diabetic wound.

Potential of Curcumin in the Management of Skin Diseases

Curcumin is a polyphenolic molecule derived from the rhizoma of Curcuma longa L. This compound has been used for centuries due to its anti-inflammatory, antioxidant, and antimicrobial properties. These make it ideal for preventing and treating skin inflammation, premature skin ageing, psoriasis, and acne. Additionally, it exhibits antiviral, antimutagenic, and antifungal effects. Curcumin provides protection against skin damage caused by prolonged exposure to UVB radiation. It reduces wound healing times and improves collagen deposition. Moreover, it increases fibroblast and vascular density in wounds. This review summarizes the available information on the therapeutic effect of curcumin in treating skin diseases. The results suggest that curcumin may be an inexpensive, well-tolerated, and effective agent for treating skin diseases. However, larger clinical trials are needed to confirm these observations due to limitations in its in vivo use, such as low bioavailability after oral administration and metabolism.

Natural compounds for oxidative stress and neuroprotection in schizophrenia: composition, mechanisms, and therapeutic potential

OBJECTIVE

An imbalance between the generation of reactive oxygen species (ROS) and the body's antioxidant defense mechanisms is believed to be a critical factor in the development of schizophrenia (SCZ) like neurological illnesses. Understanding the roles of ROS in the development of SCZ and the potential activity of natural antioxidants against SCZ could lead to more effective therapeutic options for the prevention and treatment of the illness.

METHODS

SCZ is a mental disorder characterised by progressive impairments in working memory, attention, and executive functioning. In present investigation, we summarized the experimental findings for understanding the role of oxidative stress (OS) in the development of SCZ and the potential neuroprotective effects of natural antioxidants in the treatment of SCZ.

RESULTS

Current study supports the use of the mentioned antioxidant natural compounds as a potential therapeutic candidates for the treatment of OS mediated neurodegeneration in SCZ.

DISCUSSION

Elevated levels of harmful ROS and reduced antioxidant defense mechanisms are indicative of increased oxidative stress (OS), which is associated with SCZ. Previous research has shown that individuals with SCZ, including non-medicated, medicated, first-episode, and chronic patients, exhibit decreased levels of total antioxidants and GSH. Additionally, they have reduced antioxidant enzyme levels such as catalase (CAT), glutathione (GPx), and, superoxide dismutase (SOD) and lower serum levels of brain-derived neurotrophic factor (BDNF) in their brain tissue. The mentioned natural antioxidants may assist in reducing oxidative damage in individuals with SCZ and increasing BDNF expression in the brain, potentially improving cognitive function and learning ability.

Mixed food waste valorization using a thermostable glucoamylase enzyme produced by a newly isolated filamentous fungus: A sustainable biorefinery approach

Food waste is a lucrative source of complex nutrients, which can be transformed into a multitude of bioproducts by the aid of microbial cell factories. The current study emphasizes isolating Glucoamylase enzyme (GA) producing strains that can effectively break down mixed food waste (MW), which serves as a substrate for biomanufacturing. The screening procedure relied heavily on the growth of isolated fungi on starch agar media, to specifically identify the microbes with the highest starch hydrolysis potential. A strain displayed the highest GA activity of 2.9 ± 0.14 U/ml which was selected and identified as Aspergillus fumigatus via molecular methods of identification. Exposure of the A. fumigatus with 200 mM Ethyl methanesulphonate (EMS) led to a 23.79% increase compared to the wild-type GA. The growth conditions like cultivation temperature or the number of spores in the inoculum were investigated. Further, maximum GA activity was exhibited at pH 5, 55 °C, and at 5 mM Ca2+ concentration. The GA showed thermostability, retaining activity even after long periods of exposure to temperatures as high as 95 °C. The improvement of hydrolysis of MW was achieved by Taguchi design where a maximum yield of 0.57 g g-1 glucose was obtained in the hydrolysate. This study puts forth the possibility that mixed food waste, despite containing spices and other microbial growth-inhibitory substances, can be efficiently hydrolyzed to release glucose units, by robust fungal cell factories. The glucose released can then be utilized as a carbon source for the production of value-added products.

Insights into the preventive actions of natural compounds against Klebsiella pneumoniae infections and drug resistance

Klebsiella pneumoniae is a type of Gram-negative bacteria that causes a variety of infections, including pneumonia, bloodstream infections, wound infections, and meningitis. The treatment of K. pneumoniae infection depends on the type of infection and the severity of the symptoms. Antibiotics are generally used to treat K. pneumoniae infections. However, some strains of K. pneumoniae have become resistant to antibiotics. This comprehensive review examines the potential of natural compounds as effective strategies against K. pneumonia infections. The alarming rise in antibiotic resistance underscores the urgent need for alternative therapies. This article represents current research on the effects of diverse natural compounds, highlighting their anti-microbial and antibiofilm properties against K. pneumonia. Notably, compounds such as andrographolide, artemisinin, baicalin, berberine, curcumin, epigallocatechin gallate, eugenol, mangiferin, piperine, quercetin, resveratrol, and thymol have been extensively investigated. These compounds exhibit multifaceted mechanisms, including disruption of bacterial biofilms, interference with virulence factors, and augmentation of antibiotic effectiveness. Mechanistic insights into their actions include membrane perturbation, oxidative stress induction, and altered gene expression. While promising, challenges such as limited bioavailability and varied efficacy across bacterial strains are addressed. This review further discusses the potential of natural compounds as better alternatives in combating K. pneumonia infection and emphasizes the need for continued research to harness their full therapeutic potential. As antibiotic resistance persists, these natural compounds offer a promising avenue in the fight against K. pneumonia and other multidrug-resistant pathogens.

Turmeric extract-mediated biogenic synthesis of Ag@SeO2 magnetic nanoparticles: characterization, optimization, antibacterial and antioxidant activities

This study bio-synthesized Ag@SeO2 bmNPs successfully, using turmeric ethanol extract, and characterized them using various techniques. The FT-IR analysis reveals the involvement of these plant-derived compounds, especially phenolics, in the reduction process by acting as electron donors and stabilizing/capping agents. Zeta potential analysis showed a slight negative surface charge for the stability of Ag@SeO2 NPs, where TEM revealed spherical nanoparticles with an average size of 20 nm. The XRD confirmed crystallinity and a core-shell structure, and EDX identified elements consistent with Ag@SeO2 and a 3 : 1 Ag/Se atomic ratio. Further, SEM supported the spherical shape and uniform size. These findings highlight the successful biosynthesis of Ag@SeO2 bmNPs with promising properties for diverse applications. Moreover, the Box-Behnken design (BBD) and artificial neural network (ANN) model were engaged to optimize Ag@SeO2 bmNP biosynthesis. BBD identified significant influences of pH, bioconversion temperature, time, and turmeric concentration on bmNP yield, with adjusted R2 and predictive R2 being 0.9075 and 0.8829, respectively. However, its limitations were revealed by a significant lack of fit. ANN modeling with a 3-5-7-1 topology showed superior predictive accuracy and identified optimal conditions for maximizing yield (pH 9.83, 51.7 °C, 1.0 h, 3.71 mg mL-1 turmeric). Validation experiments confirmed the model's reliability. Turmeric extract exhibited significantly higher amounts of phenolics, and flavonoids compared to the bmNPs, suggesting its potential for strong antioxidant activity. Both turmeric extract and bmNPs displayed antioxidant activity in ABTS and DPPH assays, with turmeric extract being the most potent due to its curcuminoid content. The potential activity of Ag@SeO2 bmNPs against S. aureus, K. pneumonia, E. coli, and B. cereus was investigated, with inhibition zones ranging from 22 to 32 mm. The MIC values of tested NPs towards pathogenic bacteria ranged from 165.625 and 331.25 μg mL-1.

Evaluation of phytochemical, antibacterial, thrombolytic, anti-inflammatory, and cytotoxicity profile of Achyranthes aspera aerial part extracts

This investigation was designed and performed to compare the phytochemical profiling, activities of antibacterial, thrombolytic, anti-inflammatory, and cytotoxicity of methanol extract (ME-E) and aqueous extract (AQ-E) of aerial parts of Achyranthes aspera through in-vitro approach. Also characterize the functional groups of bioactive compounds in the ME-E through Fourier-transform infrared (FTIR) spectroscopy analysis. Interestingly, qualitative phytochemical screening proved that the ME-E contain more number of vital phytochemicals such as phenolics. saponins, tannins, alkaloids, flavonoids, cardiac glycosides, steroids, and phlobatannins than AQ-E. Similarly, the ME-E showed notable antibacterial activity as dose dependent manner against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa at 1000 μg mL-1 concentration. ME-E also showed 75.2 ± 2% of clot lysis (thrombolytic activity) at 1000 μg mL-1 dosage and it followed by AQ-E 51.24 ± 3%. The ME-E showed moderate and AQ-E demonstrate poor anti-inflammatory activity evidenced by albumin denaturation inhibition and anti-lipoxygenase assays. Furthermore, the ME-E demonstrated a dose dependent cytotoxicity was noted against brine shrimp larvae. In support of this ME-E considerable activities, the Fourier transform infrared (FTIR) analysis confirmed that this extract contain more number peaks attributed to the stretch of various essential functional groups belongs to different bioactive compounds. Hence this ME-E of A. aspera can be considered for further in depth scientific investigations to validate their maximum biomedical potential.

The Michael donor-acceptor reactivity of curcumins in the synthesis of diverse multi-functional scaffolds

Curcumin is a key constituent of turmeric with a variety of biological activities. From a chemical point of view, curcumin contains different functional groups that can undergo multiple transformations such as Michael addition, cycloaddition, click reaction, polymerisation, etc. Among these, Michael-type reactions under benign conditions constitute a captivating domain of curcumin's reactivity. To the best of our knowledge, no review focusing on the Michael donor-acceptor reactivity of curcumins has been published to date. Herein, we have compiled the chemistry of curcumins with respect to their chemical synthesis, biosynthesis, and involvement in chemical transformations, especially in Michael additions with advances in mechanistic aspects and understanding.

Inhibition of pathogenic microbes in oral infectious diseases by natural products: Sources, mechanisms, and challenges

The maintenance of oral health is of utmost importance for an individual's holistic well-being and standard of living. Within the oral cavity, symbiotic microorganisms actively safeguard themselves against potential foreign diseases by upholding a multifaceted equilibrium. Nevertheless, the occurrence of an imbalance can give rise to a range of oral infectious ailments, such as dental caries, periodontitis, and oral candidiasis. Presently, clinical interventions encompass the physical elimination of pathogens and the administration of antibiotics to regulate bacterial and fungal infections. Given the limitations of various antimicrobial drugs frequently employed in dental practice, the rising incidence of oral inflammation, and the escalating bacterial resistance to antibiotics, it is imperative to explore alternative remedies that are dependable, efficacious, and affordable for the prevention and management of oral infectious ailments. There is an increasing interest in the creation of novel antimicrobial agents derived from natural sources, which possess attributes such as safety, cost-effectiveness, and minimal adverse effects. This review provides a comprehensive overview of the impact of natural products on the development and progression of oral infectious diseases. Specifically, these products exert their influences by mitigating dental biofilm formation, impeding the proliferation of oral pathogens, and hindering bacterial adhesion to tooth surfaces. The review also encompasses an examination of the various classes of natural products, their antimicrobial mechanisms, and their potential therapeutic applications and limitations in the context of oral infections. The insights garnered from this review can support the promising application of natural products as viable therapeutic options for managing oral infectious diseases.

Synergistic effects of nano curcumin mediated photodynamic inactivation and nano-silver@colistin against Pseudomonas aeruginosa biofilms

BACKGROUND

Patients with burn injuries colonized by multidrug-resistant Pseudomonas aeruginosa face increased mortality risk. The efficacy of colistin, a last-resort treatment, is declining as resistance levels rise. P. aeruginosa's robust biofilm exacerbates antibiotic resistance. Photodynamic Inactivation (PDI) shows promise in fighting biofilm.

MATERIALS AND METHODS

Nano curcumin (nCur) particles were synthesized, and their chemical characteristics were determined using zeta potential (ZP), dynamic light scattering analysis (DLS), energy-dispersive X-ray (EDX) analysis, and fourier transform infrared (FTIR). We conducted an MTT assay to assess the cytotoxicity of nCur-mediated PDI in combination with nanosilver colistin. The fractional biofilm inhibitory concentration (FBIC) of two P. aeruginosa clinical isolates and P. aeruginosa ATCC 27853 during nCur-mediated PDI@AgNPs@CL was determined using a 3-dimensional (3-D) checkerboard assay. To study the effect of nCur-mediated PDI@AgNPs@CL on lasI, lasR, rhlI, rhlR, pelA, and pslA gene expression, Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was conducted at each isolate's FBIC. The impact of treatments was also investigated using scanning electron microscopy (SEM).

RESULTS

The ZP and mean DLS values of the nCur were 10.3 mV and 402.6 ± 24.6 nm, respectively. The distinct functional groups of nCur corresponded with the peaks of FTIR absorption. Moreover, the EDX analysis showed the ratios of different metals in nCur. Cell viability percentages of nCur-mediated PDI@AgNPs@CL at FBIC concentrations of clinical isolates Nos. 30, 354, and P. aeruginosa ATCC 27853 were 91.36 %, 83.20 %, and 92.48 %, respectively. nCur-mediated PDI@AgNPs@CL treatment showed synergistic effects in clinical isolates and P. aeruginosa ATCC 27853 in a 3-D checkerboard assay. All six of the investigated genes showed down-regulation after nCur-mediated PDI@AgNPs@CL treatment. The most suppressed gene during nCur-mediated PDI@AgNPs@CL treatment was the rhlR gene (-11.9-fold) of P. aeruginosa ATCC 27853. The SEM micrographs further proved the connecting cement reduction and biofilm mass mitigation following nCur-mediated PDI@AgNPs@CL treatments.

CONCLUSIONS

The combined effect of nCur-mediated PDI and AgNPs@CL synergistically reduce the formation of biofilm in P. aeruginosa. This may be attributable to the suppression of the genes responsible for regulating the production of biofilms.

Apricot polysaccharides as new carriers to make curcumin nanoparticles and improve its stability and antibacterial activity

Apricot polysaccharides (APs) as new types of natural carriers for encapsulating and delivering active pharmaceutical ingredients can achieve high-value utilization of apricot pulp and improve the solubility, the stability, and the antibacterial activity of insoluble compounds simultaneously. In this research, the purified APs reacted with bovine serum albumin (BSA) by the Maillard reaction, and with d-α-tocopheryl succinate (TOS) and pheophorbide A (PheoA) by grafting to fabricate two materials for the preparation of curcumin (Cur)-encapsulated AP-BSA nanoparticles (CABNs) and Cur-embedded TOS-AP-PheoA micelles (CTAPMs), respectively. The biological activities of two Cur nano-delivery systems were evaluated. APs consisted of arabinose (22.36%), galactose (7.88%), glucose (34.46%), and galacturonic acid (31.32%) after the optimized extraction. Transmission electron microscopy characterization of CABNs and CTAPMs displayed a discrete and non-aggregated morphology with a spherical shape. Compared to the unencapsulated Cur, the release rates of CABNs and CTAPMs decreased from 87% to 70% at 3 h and from 92% to 25% at 48 h, respectively. The antioxidant capacities of CABNs and CTAPMs were significantly improved. The CTAPMs exhibited a better antibacterial effect against Escherichia coli than CABNs due to the synergistic photosensitive effect between Cur and PheoA.

Effect of Resveratrol and Curcumin on Gene Expression of Methicillin-Resistant Staphylococcus aureus (MRSA) Toxins

Staphylococcus aureus is an opportunistic pathogen that can lead to a number of potentially terrible community- and hospital-acquired illnesses. Among the diverse set of virulence factors that S. aureus possesses, secreted toxins play a particularly preeminent role in defining its virulence. In this work, we aimed to facilitate the development of novel strategies utilizing natural compounds to lower S. aureus's toxin production and consequently enhance therapeutic approaches. Two natural polyphenols, resveratrol (RSV) and curcumin (CUR), were tested for their effect on reducing toxin gene production of MRSA isolates. Fifty clinical MRSA isolates were gathered from Riyadh and Jeddah. Molecular screening of toxin genes (sea, seb, sec, sed, seh, lukF, and lukS) harbored by MRSA was performed. Sub-inhibitory concentrations of RSV (50 μg/ml) and CUR (20 μg/ml) were determined to study their effect on the gene expression MRSA's toxin genes. Our findings revealed the presence of the tested genes in MRSA isolates, with lukF being the most prevalent gene and seh the least detected gene. We found that RSV reduced the relative expression of toxin genes, sea, seb, lukF, and lukS, respectively, while CUR decreased the relative expression of sea and seb genes in the examined isolates. Regarding lukF and lukS, CUR downregulated the expression of both genes in some isolates and upregulated the expression in other isolates. From these results, we concluded that RSV and CUR could be used as alternative therapeutic approaches to treat MRSA infections through reducing toxin production.

On-Demand Sequential Release of Dual Drug from pH-Responsive Electrospun Janus Nanofiber Membranes toward Wound Healing and Infection Control

Drugs against bacteria and abnormal cells, such as antibiotics and anticancer drugs, may save human lives. However, drug resistance is becoming more common in the clinical world. Nowadays, a synergistic action of multiple bioactive compounds and their combination with smart nanoplatforms has been considered an alternative therapeutic strategy to fight drug resistance in multidrug-resistant cancers and microorganisms. The present study reports a one-step fabrication of innovative pH-responsive Janus nanofibers loaded with two active compounds, each in separate polymer compartments for synergistic combination therapy. By dissolving one of the compartments from the nanofibers, we could clearly demonstrate a highly yielded anisotropic Janus structure with two faces by scanning electron microscopy (SEM) analysis. To better understand the distinctive attributes of Janus nanofibers, several analytical methods, such as X-ray diffraction (XRD), FTIR spectroscopy, and contact angle goniometry, were utilized to examine and compare them to those of monolithic nanofibers. Furthermore, a drug release test was conducted in pH 7.4 and 6.0 media since the properties of Janus nanofibers correlate significantly with different environmental pH levels. This resulted in the on-demand sequential codelivery of octenidine (OCT) and curcumin (CUR) to the corresponding pH stimulus. Accordingly, the antibacterial properties of Janus fibers against Escherichia coli and Staphylococcus aureus, tested in a suspension test, were pH-dependent, i.e., greater in pH 6 due to the synergistic action of two active compounds, and Eudragit E100 (EE), and highly satisfactory. The biocompatibility of the Janus fibers was confirmed in selected tests.

Strength properties and ability to dissipate mechanical energy of biopolypropylene basalt/cellulose composites with the addition of antibacterial turmeric

The aim of this study was to evaluate the possibility of producing novel reinforced biocomposites based on polypropylene produced from biomass with the addition of antibacterial turmeric as a natural antibacterial agent for the manufacturing of orthoses and other small external medical equipment. Six hybrid composites containing 5-15% basalt fibers, 5-15% microcellulose fibers, 2% turmeric powder and 2% anhydride maleic compatibilizer were produced on a biobased polypropylene matrix by injection molding. The basic strength properties were determined in a static tensile, bending and impact test. The low-cycle dynamic test was carried out to determine changes in dissipation energy and the development of relaxation processes. In order to assess the microstructure of the composites, SEM micrographs were taken after the tensile test. The obtained results confirm that it was possible to produce functional biocomposites based on biopolypropylene with the addition of basalt and lignocellulosic fibers modified with natural antibacterial turmeric. Based on the results of strength properties tests, it can be seen that the addition of basalt fibers increases strength and stiffness, while microcellulose particles reduce the ability to dissipate mechanical energy, and in both cases water has a plasticizing effect on the produced composites. The addition of fibers increases the flexural modulus by 39-196% and is higher the higher the fiber content. The most promising seem to be hybrid composites with a balanced proportion of 10:10 and 15:15 basalt and EFC fibers, which are characterized by 20% higher strength and almost two and a half times higher stiffness than neat polypropylene.

Synthesis of aminolyzed gelatin-mediated chitosan as pH-responsive drug-carrying porous scaffolds

Bio-based drug delivery devices have gained enormous interest in the biomedical field due to their biocompatible attributes. Extensive research is being conducted on chitosan-based devices for drug delivery applications. Chitosan being hydrophobic under neutral conditions makes it difficult to interact with a polar drug of curcumin. We tended to make it polar through sol-gel synthesis and modification via PEGylation, alkaline hydrolysis, and aminolysis. Such alterations could make the chitosan-based scaffolds porous, hydrophilic, amino-functionalized, and pH-responsive. The ninhydrin assay confirmed that a successful aminolysis occurred, and the chemical interaction among the precursors was explained under infrared spectroscopy. The scanning morphology of the optimum aminolyzed membrane appeared to be porous with an average pore size of 320 ± 20 nm. The aminolyzed chitosan membrane was found thermally stable up to 310 °C, hydrophilic with a water contact angle of 23.4°, moderate flowablity, and porous (97 ± 5 %, w/w) against ethanol. The curcumin-loaded chitosan membrane expressed the UV-protection behavior of 99 %. The curcumin-loading and release phenomena were found pH-responsive. The curcumin release results were evaluated through specific kinetic models. This study could be the first report on the amphiphilic, porous, and swellable drug-loaded gelatin/chitosan membrane with pH-responsive loading and release of curcumin for potential drug delivery applications.

Ethyl cellulose/gelatin/β-cyclodextrin/curcumin nanofibrous membrane with antibacterial and formaldehyde adsorbable capabilities for lightweight and high-performance air filtration

Functionalization of bio-based nanofibers is the development tendency of high-performance air filter. However, the conventional structural optimization strategy based on high solution conductivity greatly hinders the development of fully bio-based air filter, and not conducive to sustainable development. This work fabricated fully bio-based nanofibrous membrane with formaldehyde-adsorbable and antibacterial capabilities by electrospinning low-conductivity solution for high-performance air filtration and applied to lightweight mask. The "water-like" ethyl cellulose (EC) was selected as the base polymer to "nourish" functional materials of gelatin (GE), β-cyclodextrin (βCD), and curcumin (Cur), thus forming a solution system with high binding energy differences and electrospinning into ultrafine bimodal nanofibers. The filtration efficiency for 0.3 μm NaCl particles, pressure drop, and quality factor were 99.25 %, 53 Pa, and 0.092 Pa-1, respectively; the bacteriostatic rates against Escherichia coli and Staphylococcus aureus were 99.9 % and 99.4 %, respectively; the formaldehyde adsorption capacity was 442 μg/g. This is the first report on antibacterial and formaldehyde-adsorbable high-performance air filter entirely made from bio-based materials. This simple strategy will greatly broaden the selection of materials for preparing high-performance multifunctional air filter, and promote the development of bio-based air filter.

Emulsion template fabricated gelatin-based scaffold functionalized by dialdehyde starch complex with antibacterial antioxidant properties for accelerated wound healing

Gelatin and starch are considered as promising sustainable materials for their abundant production and good biodegradability. Efforts have been made to explore their medical application. Herein, scaffolds based on gelatin and starch with a preferred microstructure and antibacterial antioxidant property were fabricated by the emulsion template method. The dialdehyde starch was firstly combined with silver nanoparticles and curcumin to carry out the efficient hybrid antibacterial agent. Then, the gelatin microsphere of appropriate size was prepared by emulsification and gathered by the above agent to obtain gelatin-based scaffolds. The prepared scaffolds showed porous microstructures with high porosity of over 74 % and the preferred pore sizes of ∼65 μm, which is conducive to skin regeneration. Moreover, the scaffolds possessed a good swelling ability of over 640 %, good degradability of over 18 days, excellent blood compatibility, and cell compatibility. The promising antibacterial and antioxidant properties came from the hybrid antibacterial agent were affirmed. As expected, the gelatin-based scaffolds fabricated by the emulsion template method with a preferred microstructure can facilitate more adhered fibroblasts. In summary, gelatin-based scaffolds functionalized by starch-based complex expanded the application of abundant sustainable materials in the biomedical field, especially as antibacterial antioxidant wound dressings.

Herbal active ingredient-loaded poly(ω-pentadecalactone-co-δ-valerolactone)/gelatin nanofibrous membranes

Recently, there has been an accelerating interest in novel biocompatible wound dressings made of nano-sized materials, especially nanofibers. Electrospun nanofibers provide high surface area and mimic the extracellular matrix which enhances biocompatibility. Besides, nanofibrous structures have high active ingredient loading capacity as a result of their high surface-to-volume ratio and porosity. In the present study, curcumin-loaded poly(ω-pentadecalactone-co-δ-valerolactone)/gelatin (PDL-VL/Gel) nanofibrous membranes were fabricated to be used for healing skin wounds. Poly(ω-pentadecalactone-co-δ-valerolactone) copolymer has been enzymatically synthesized in previous studies, thus it improves the originality of the membrane. It was aimed to obtain a synergetic effect and increase the novelty of the work by blending synthetic and natural polymers. Moreover, it was preferred to provide antibacterial activity by the incorporation of a herbal ingredient (curcumin) as a natural alternative to commercial antibiotics. Varied amounts of curcumin (5-25 %, w:v) were electrospun together with PDL-VL/Gel (equal volume ratio) polymer blend (fiber diameters ranged between 554 and 1074 nm) and several characterizations (morphological and molecular structure, wettability characteristics, and thermal behavior) were applied to examine the curcumin incorporation. Afterwards, in vitro curcumin release studies were carried out and mathematical modeling was applied to release data to clarify the transport mechanism. Curcumin release profiles comprised of an initial burst release in the first hour followed by a sustained release through 24 h. Based on the antibacterial activity test results, 15 % curcumin loading ratio was found to be sufficient for the treatment of skin wounds infected by Gram-negative (E. coli) and Gram-positive (S. aureus and B. subtilis) bacteria. Additionally, nanofibrous membranes did not lead to cytotoxicity, and curcumin content further enhanced the viability of fibroblasts. Thus, the presented antibacterial nanofibrous membrane is suggested to be applied for the treatment of wound infections and accelerating the healing process.

Perspective of Secondary Metabolites in Respect of Multidrug Resistance (MDR): A Review

Aberrant and haphazard use of antibiotics has created the development of antimicrobial resistance which is a bizarre challenge for human civilization. This emerging crisis of antibiotic resistance for microbial pathogens is alarming all the nations posing a global threat to human health. It is difficult to treat bacterial infections as they develop resistance to all antimicrobial resistance. Currently used antibacterial agents inhibit a variety of essential metabolic pathways in bacteria, including macro-molecular synthesis (MMS) pathways (e.g. protein, DNA, RNA, cell wall) most often by targeting a specific enzyme or subcellular component e.g. DNA gyrase, RNA polymerase, ribosomes, transpeptidase. Despite the availability of diverse synthetic molecules, there are still many complications in managing progressive and severe antimicrobial resistance. Currently not even a single antimicrobial agent is available for which the microbes do not show resistance. Thus, the lack of efficient drug molecules for combating microbial resistance requires continuous research efforts to overcome the problem of multidrug-resistant bacteria. The phytochemicals from various plants have the potential to combat the microbial resistance produced by bacteria, fungi, protozoa and viruses without producing any side effects. This review is a concerted effort to identify some of the major active phytoconstituents from various medicinal plants which might have the potential to be used as an alternative and effective strategy to fight against microbial resistance and can promote research for the treatment of MDR.

Toward a Platform for the Treatment of Burns: An Assessment of Nanoemulsions vs. Nanostructured Lipid Carriers Loaded with Curcumin

Curcumin is a highly promising substance for treating burns, owing to its anti-inflammatory, antioxidant, antimicrobial, and wound-healing properties. However, its therapeutic use is restricted due to its hydrophobic nature and low bioavailability. This study was conducted to address these limitations; it developed and tested two types of lipid nanocarriers, namely nanoemulsions (NE-CUR) and nanostructured lipid carriers (NLC-CUR) loaded with curcumin, and aimed to identify the most suitable nanocarrier for skin burn treatment. The study evaluated various parameters, including physicochemical characteristics, stability, encapsulation efficiency, release, skin permeation, retention, cell viability, and antimicrobial activity. The results showed that both nanocarriers showed adequate size (~200 nm), polydispersity index (~0.25), and zeta potential (~>-20 mV). They also showed good encapsulation efficiency (>90%) and remained stable for 120 days at different temperatures. In the release test, NE-CUR and NCL-CUR released 57.14% and 51.64% of curcumin, respectively, in 72 h. NE-CUR demonstrated better cutaneous permeation/retention in intact or scalded skin epidermis and dermis than NLC-CUR. The cell viability test showed no toxicity after treatment with NE-CUR and NLC-CUR up to 125 μg/mL. Regarding microbial activity assays, free curcumin has activity against P. aeruginosa, reducing bacterial growth by 75% in 3 h. NE-CUR inhibited bacterial growth by 65% after 24 h, and the association with gentamicin had favorable results, while NLC-CUR showed a lower inhibition. The results demonstrated that NE-CUR is probably the most promising nanocarrier for treating burns.

Curcumin nanocrystals-in-nanofibres as a promising platform for the management of periodontal disease

It is estimated that nearly a half of the world's population over 30 years old suffer from some kind of periodontal disease (PD). Although preventable, PD can pose a significant health burden to patients, causing from pain and discomfort to disfigurement and death. The management of PD often requires surgical procedures accompanied of systemic antibiotic and anti-inflammatory treatments. Curcumin (CUR), a potent anti-inflammatory and antimicrobial active, has shown great promise in the management of PD; however, its effects are often limited by its low bioavailability. In this work, we report the development of electrospun nanofibres (NFs) loaded with CUR nanocrystals (NCs) for the management of PD. NCs of 100 nm were obtained by media milling and loaded into dissolving polyvinyl alcohol NFs using electrospinning. The resultant NCs-in-NFs dissolved in water spontaneously, releasing NCs with a particle size of ∼120 nm. The physiochemical characterisation of the systems indicated the absence of chemical interactions between drug and polymer, and nanofibres with an amorphous nature. In vitro release profiles demonstrated that the NCs had a significantly higher dissolution rate (∼100 % at day 40) than the control group (approximately 6 % at day 40), which consisted of NFs containing a physical mixture of the drug and stabiliser. Finally, mucosal deposition studies demonstrated a 10-fold higher capacity of the novel NCs-in-NFs system to deposit CUR ex vivo using excised neonatal porcine mucosal tissue, when compared to the control group.

ROS-responsive hydrogels with spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs for the repair of MRSA-infected wounds

For the treatment of MRSA-infected wounds, the spatiotemporally sequential delivery of antibacterial and anti-inflammatory drugs is a promising strategy. In this study, ROS-responsive HA-PBA/PVA (HPA) hydrogel was prepared by phenylborate ester bond cross-linking between hyaluronic acid-grafted 3-amino phenylboronic acid (HA-PBA) and polyvinyl alcohol (PVA) to achieve spatiotemporally controlled release of two kinds of drug to treat MRSA-infected wound. The hydrophilic antibiotic moxifloxacin (M) was directly loaded in the hydrogel. And hydrophobic curcumin (Cur) with anti-inflammatory function was first mixed with Pluronic F127 (PF) to form Cur-encapsulated PF micelles (Cur-PF), and then loaded into the HPA hydrogel. Due to the different hydrophilic and hydrophobic nature of moxifloxacin and Cur and their different existing forms in the HPA hydrogel, the final HPA/M&Cur-PF hydrogel can achieve different spatiotemporally sequential delivery of the two drugs. In addition, the swelling, degradation, self-healing, antibacterial, anti-inflammatory, antioxidant property, and biocompatibility of hydrogels were tested. Finally, in the MRSA-infected mouse skin wound, the hydrogel-treated group showed faster wound closure, less inflammation and more collagen deposition. Immunofluorescence experiments further confirmed that the hydrogel promoted better repair by reducing inflammation (TNF-α) and promoting vascular (VEGF) regeneration. In conclusion, this HPA/M&Cur-PF hydrogel that can spatiotemporally sequential deliver antibacterial and anti-inflammatory drugs showed great potential for the repair of MRSA-infected skin wounds.

pH-Responsive Injectable Multifunctional Pluronic F127/Gelatin-Based Hydrogels with Hydrogen Production for Treating Diabetic Wounds

Diabetic chronic wounds remain a major clinical challenge with long-term inflammatory responses and extreme oxidative damage. Hence, a pH-responsive injectable multifunctional hydrogel [Gel/CUR-FCHO/Mg (GCM) micromotors] via a Schiff base reaction between gelatin and benzaldehyde-grafted Pluronic F127 drug-loaded micelles (FCHO) was fabricated for the first time. Dynamic Schiff base linkage endowed the GCM hydrogel with the ability to be self-healing, injectable, and pH-responsive for on-demand drug delivery at the wound site. Curcumin (CUR), a hydrophobic drug with antioxidative, anti-inflammatory, and antibacterial activities, was encapsulated into the hydrogel matrix by micellization (CUR-FCHO micelles). Simultaneously, magnesium-based micromotors (Mg micromotors) were physically entrapped into the system for providing active hydrogen (H2) to scavenge reactive oxygen species and alleviate inflammatory responses. As a result, the GCM micromotor hydrogel displayed an inherent antibacterial property, extraordinary antioxidative performance, and remarkable biocompatibility. In the diabetic mouse with a full-thickness cutaneous defect wound, the GCM hydrogel could remodel the inflammatory microenvironment and stimulate vascularization and collagen deposition, thereby facilitating wound closure and enhancing tissue regeneration, which offered a promising therapeutic option for diabetic chronic wound management.

Antimicrobial photodynamic therapy with dendrosomal curcumin and blue laser against Porphyromonas gingivalis

BACKGROUND

Periodontitis is a chronic inflammatory disease that leads to the loss of tooth-supporting structures. Porphyromonas gingivalis is one of the main pathogens responsible for periodontitis. Because of the limitations of antibiotic use, various alternative approaches have been developed. Antimicrobial photodynamic therapy uses photosensitizers and light to eliminate pathogens. Curcumin is a promising photosensitizer, but has low bioavailability and water solubility. However, dendrosomes can efficiently encapsulate curcumin, overcoming these obstacles. This study aimed to evaluate the efficacy of photodynamic therapy with blue laser and dendrosomal curcumin against Porphyromonas gingivalis.

METHODS

In this in vitro experiment, the minimum inhibitory concentration (MIC) of dendrosomal curcumin was determined using a serial dilution approach. Porphyromonas gingivalis suspensions were subjected to blue laser irradiation (447 nm, output power 100 mW) for 30 to 180 s. Finally, several subMIC dendrosomal curcumin concentrations and blue laser irradiation periods were applied to the bacterial suspensions. The negative control group received no therapy, whereas the positive control group was treated with 0.2% chlorhexidine. Consequently, the colony count of each group was calculated.

RESULTS

Treatment of Porphyromonas gingivalis with dendrosomal Curcumin at concentrations of 8-250 μg/mL significantly reduced bacterial growth compared to untreated group. 90 second exposure to a blue laser (31.8 J/cm2) completely inhibited the growth of Porphyromonas gingivalis. Blue laser irradiation for 60 s (21.2 J/cm2) markedly reduced bacterial growth but did not completely prevent its survival. Photodynamic therapy using dendrosomal curcumin at concentrations of 2-4 μg/mL and irradiation for 30-90 s resulted in complete eradication of Porphyromonas gingivalis compared to controls (P < 0.05).

CONCLUSION

The reduction in survival of Porphyromonas gingivalis following photodynamic therapy with dendrosomal curcumin and blue laser indicates that this technique could be a useful approach to eradicate Porphyromonas gingivalis infections.