Antibacterial effects of curcumin: An in vitro minimum inhibitory concentration study

Soft nanoparticles as antimicrobial agents and carriers of microbiocides for enhanced inhibition activity

Antibiotic resistance continues to pose significant health challenges. Considering severe limitations in the discovery and supply of new antibiotics, there is an unmet need to design alternative and more effective strategies for addressing this global issue. Use of polymeric nanoparticles with cationic shell surfaces offers a highly promising approach to coupling their inherent bactericidal action with sustained delivery of small lipophilic microbicides. We have utilized this platform for assembling multi-tasking soft core-shell nanoparticles from star polymers with the desired asymmetric arm composition. These stable nanoparticles with low critical micelle concentration imparted intrinsic antimicrobial potency due to high positive charge density in the corona, as well as the loading of active biocidal agents (such as curcumin and terbinafine) for potential dual and coadjuvant inhibition. This strategic combination allows for both immediate (direct contact) and extended (drug delivery) antibacterial activities for better therapeutic efficacy. Micellar nanoparticles with and without therapeutic cargo were highly efficient against both Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis), representative Gram-negative and Gram-positive bacteria, respectively. Interestingly, we observed bacteria- and concentration-dependent effects, in which higher concentrations of charged nanoparticles were more effective against E. coli, whereas B. subtilis was inhibited only at lower concentrations. This work highlights a valuable platform to achieve combination therapy through nanoparticles with charged coronas and delivery of potent therapeutics to overcome antimicrobial resistance.

The potential therapeutic role of curcumin in osteoporosis treatment: based on multiple signaling pathways

Osteoporosis is a common chronic metabolic bone disease caused by disturbances in normal bone metabolism and an imbalance between osteoblasts and osteoclasts. Osteoporosis is characterized by a decrease in bone mass and bone density, leading to increased bone fragility. Osteoporosis is usually treated with medications and surgical methods, but these methods often produce certain side effects. Therefore, the use of traditional herbal ingredients for the treatment of osteoporosis has become a focus of attention and a hot topic in recent years. Curcumin, widely distributed among herbs such as turmeric, tulip, and curcuma longa, contains phenolic, terpenoid, and flavonoid components. Modern pharmacological studies have confirmed that curcumin has a variety of functions including antioxidant and anti-inflammatory properties. In addition, curcumin positively regulates the differentiation and promotes the proliferation of osteoblasts, which play a crucial role in bone formation. Multiple studies have shown that curcumin is effective in the treatment of osteoporosis as it interacts with a variety of signaling pathway targets, thereby interfering with the formation of osteoblasts and osteoclasts and regulating the development of osteoporosis. This review summarized the key signaling pathways and their mechanisms of action of curcumin in the prevention and treatment of osteoporosis and analyzed their characteristics and their relationship with osteoporosis and curcumin. This not only proves the medicinal value of curcumin as a traditional herbal ingredient but also further elucidates the molecular mechanism of curcumin's anti-osteoporosis effect, providing new perspectives for the prevention and treatment of osteoporosis through multiple pathways.

Capsaicin: Emerging Pharmacological and Therapeutic Insights

Capsaicin, the most prominent pungent compound of chilli peppers, has been used in traditional medicine systems for centuries; it already has a number of established clinical and industrial applications. Capsaicin is known to act through the TRPV1 receptor, which exists in various tissues; capsaicin is hepatically metabolised, having a half-life correlated with the method of application. Research on various applications of capsaicin in different formulations is still ongoing. Thus, local capsaicin applications have a pronounced anti-inflammatory effect, while systemic applications have a multitude of different effects because their increased lipophilic character ensures their augmented bioavailability. Furthermore, various teams have documented capsaicin's anti-cancer effects, proven both in vivo and in vitro designs. A notable constraint in the therapeutic effects of capsaicin is its increased toxicity, especially in sensitive tissues. Regarding the traditional applications of capsaicin, apart from all the effects recorded as medicinal effects, the application of capsaicin in acupuncture points has been demonstrated to be effective and the combination of acupuncture and capsaicin warrants further research. Finally, capsaicin has demonstrated antimicrobial effects, which can supplement its anti-inflammatory and anti-carcinogenic actions.

Determination of the impacts of supplemental dietary curcumin on post-partum uterine involution using pulsed-wave doppler ultrasonography in Zaraibi goat

This study aimed to evaluate the impacts of supplemental dietary curcumin on post-partum uterine involution using pulsed-wave Doppler ultrasonography in postpartum goats. Ten pluriparous Zaraibi goats were used and divided into two groups. Group 1 (n = 5; control) received only a base diet. Group 2 (n = 5; treated) received a base diet supplemented with curcumin (200 mg/kg diet) daily for 28 days, starting from day 1 postpartum (PP) till day 28 PP. Uterine morphometrical changes (uterine horn diameter; UHD and caruncle diameter; CD), uterine hemodynamics (resistance and pulsatility indices (RI and PI), systolic/ diastolic ratio (S/D), peak systolic velocity (PSV), end-diastolic velocity (EDV), blood flow volume (BFV), and blood flow rate (BFR)), and progesterone level were evaluated. Results revealed that the diameter of the uterine horn decreased rapidly from day 1 to day 10 PP (> 50%) but more steadily from day 14 to day 28 PP in both groups. After day 21 PP, there was nearly no reduction in UHD and CD in both groups. The treated group had lower values of the RI and PI (P < 0.05) than the control group. Regarding the BFR and BFV in the treated group, there was a significant increase (P < 0.05) on day 17 PP, then started to decrease till day 28 PP. While in the control group, there was a significant decrease (P < 0.05) in BFR and BFV from day 1 PP till day 28 PP. In conclusion, the incorporation of curcumin in the diet of PP Zaraibi goats improved reproductive performance via improvements in uterine morphometric changes as well as blood perfusion.

Assessment of Antimicrobial and Cytotoxic Activities of Liposomes Loaded with Curcumin and Lippia origanoides Essential Oil

(1) Introduction: Curcumin and Lippia origanoides essential oils have a broad spectrum of biological activities; however, their physicochemical instability, low solubility, and high volatility limit their therapeutic use. Encapsulation in liposomes has been reported as a feasible approach to increase the physicochemical stability of active substances, protect them from interactions with the environment, modulate their release, reduce their volatility, improve their bioactivity, and reduce their toxicity. To date, there are no reports on the co-encapsulation of curcumin and Lippia origanoides essential oils in liposomes. Therefore, the objective of this work is to prepare and physiochemical characterize liposomes loaded with the mixture of these compounds and to evaluate different in vitro biological activities. (2) Methods: Liposomes were produced using the thin-layer method and physiochemical characteristics were calculated. The antimicrobial and cytotoxic activities of both encapsulated and non-encapsulated compounds were evaluated. (3) Results: Empty and loaded nanometric-sized liposomes were obtained that are monodisperse and have a negative zeta potential. They inhibited the growth of Staphylococcus aureus and did not exhibit cytotoxic activity against mammalian cells. (4) Conclusions: Encapsulation in liposomes was demonstrated to be a promising strategy for natural compounds possessing antimicrobial activity.

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.

Medical properties, market potential, and microbial production of golden polyketide curcumin for food, biomedical, and cosmetic applications

Curcumin, a potent plant polyketide in turmeric, has gained recognition for its outstanding health benefits, including anti-inflammatory, antioxidant, and anticancer effects. Classical turmeric farming, which is widely used to produce curcumin, is linked to deforestation, soil degradation, excessive water use, and reduced biodiversity. In recent years, the microbial synthesis of curcumin has been achieved and optimized through novel strategies, offering increased safety, improved sustainability, and the potential to revolutionize production. Here, we discuss recent breakthroughs in microbial engineering and fermentation techniques, as well as their capacity to increase the yield, purity, and cost-effectiveness of curcumin production. The utilization of microbial systems not only addresses supply chain limitations but also helps meet the growing demand for curcumin in various industries, including pharmaceuticals, foods, and cosmetics.

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.

Diacetylcurcumin: a novel strategy against Enterococcus faecalis biofilm in root canal disinfection

Aim: We evaluated Diacetylcurcumin (DAC), a derivative of curcumin, for its antibacterial and antibiofilm properties against Enterococcus faecalis. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined, along with antibiofilm potential and toxicity in Galleria mellonella. Additionally, in silico computational analysis was performed to understand its mechanisms of action. Results & conclusion: DAC demonstrated significant antibacterial effects, with MIC and MBC values of 15.6 and 31.25 μg/ml, respectively, and reduced biofilm formation. A synergistic effect, reducing biofilm by 77%, was observed when combined with calcium hydroxide. G. mellonella toxicity tests confirmed DAC's safety at tested concentrations, suggesting its potential for use in root canal disinfection products.

Synergistic antimicrobial photodynamic therapy using gated mesoporous silica nanoparticles containing curcumin and polymyxin B

Photodynamic Therapy is a therapy based on combining a non-toxic compound, known as photosensitizer (PS), and irradiation with light of the appropriate wavelength to excite the PS molecule. The photon absorption by the PS leads to reactive oxygen species generation and a subsequent oxidative burst that causes cell damage and death. In this work, we report an antimicrobial nanodevice that uses the activity of curcumin (Cur) as a PS for antimicrobial Photodynamic Therapy (aPDT), based on mesoporous silica nanoparticles in which the action of the classical antibiotic PMB is synergistically combined with the aPDT properties of curcumin to combat bacteria. The synergistic effect of the designed gated device in combination with irradiation with blue LED light (470 nm) is evaluated against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus epidermidis. The results show that the nanodevice exhibits a noteworthy antibacterial activity against these microorganisms, a much more significant effect than free Cur and PMB at equivalent concentrations. Thus, 0.1 µg/mL of MSNs-Cur-PMB eliminates a bacterial concentration of about 105 CFU/mL of E. coli, while 1 µg/mL of MSNs-Cur-PMB is required for P. aeruginosa and S. epidermidis. In addition, antibiofilm activity against the selected bacteria was also tested. We found that 0.1 mg/mL of MSNs-Cur-PMB inhibited 99 % biofilm formation for E. coli, and 1 mg/mL of MSNs-Cur-PMB achieved 90 % and 100 % inhibition of biofilm formation for S. epidermidis and P. aeruginosa, respectively.

Antibacterial effect of curcumin on Salmonella Typhimurium: In vitro and food model studies

Salmonellosis is a major foodborne disease transmitted from contaminated poultry products worldwide. Although a wide variety of chemical agents are used in the prevention of foodborne Salmonella spp. infections, consumers prefer natural additives, that do not harm human health and do not impair the characteristics of food. Curcumin is a yellow-coloured, hydrophobic polyphenol obtained from the rhizome of the Curcuma longa L. plant known as turmeric. The purpose of this study was to evaluate curcumin's antibacterial activity against S. Typhimurium in chicken meat and in vitro. In the first step, chicken samples were experimentally contaminated with S. Typhimurium at a level of 2.8 × 10-7 CFU/ml. Then, they were kept in a 1, 2, and 3% curcumin solution for 15 minutes. At the end of the treatment, chicken samples were stored at +4 °C. The number of S. Typhimurium in chicken samples was determined according to EN ISO 6579-1. In the result of the study, the number of S. Typhimurium decreased by 2.37, 2.71, and 2.84 log levels at the end of the 6th day as a result of the 1, 2 and 3% curcumin treatment, respectively. The MIC value of curcumin was determined to be 362 μg/ml for S. Typhimurium.

Investigating bacteriophages as a novel multiple-hurdle measure against Campylobacter: field trials in commercial broiler plants

Campylobacter mitigation along the food production chain is considered effective for minimizing the public health burden of human campylobacteriosis. This study is the first combining different measures in a multiple-hurdle approach, using drinking water additives and feed additives in single and combined application schemes in commercial broiler plants. Broiler chickens in the study groups were naturally contaminated with Campylobacter. Application of an organic acid blend via drinking water, consisting of sodium propionate, potassium sorbate, and sodium diacetate, resulted in significant reductions of up to 4.9 log10 CFU/mL in fecal samples and in cecal samples at slaughter. The application of a phage mixture, consisting of Fletchervirus phage NCTC 12673 and Firehammervirus phage vB_CcM-LmqsCPL1/1, resulted in reductions of up to 1.1 log10 CFU/mL in fecal samples 1 day after dosing. The sole administration of curcumin via feed resulted in small and inconsistent reductions. In the group receiving a combination of all tested measures, reductions of up to 1.1 log10 CFU/mL were observed. Based on the results of our field trials, it was shown that both the sole application and the combined application of mitigation measures in primary production can reduce the Campylobacter load in broiler chickens, while no synergism could be observed.

Design, Synthesis, Antimicrobial Properties, and Molecular Docking of Novel Furan-Derived Chalcones and Their 3,5-Diaryl-∆2-pyrazoline Derivatives

The present work focuses on the synthesis and preliminary structure activity relationships (SARs) of furan-derived chalcones and their corresponding ∆2-pyrazoline derivatives as antimicrobial agents. Eight novel chalcone derivatives and eight ∆2-pyrazoline compounds were synthesized in moderate to good isolated yields. The target compounds were evaluated as antimicrobial agents against two Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis), two Gram-negative (Escherichia coli and Klebsiella pneumoniae), and fungi (Candida albicans) species. Based on the SARs, chalcones 2a and 2h showed inhibition activity on all tested microbial species, while ∆2-pyrazoline 3d was found to be selective for some microbial species. The most potent compounds (2a, 2h, and 3d) were docked into glucosamine-6-phosphate synthase (GlcN-6-P), the molecular target enzyme for antimicrobial agents, utilizing the Autodock 4.2 program, in order to study their virtual affinity and binding mode with the target enzyme. The selected potent compounds were found to bind to the active site of the enzyme probably in a similar way to that of the substrate as suggested by the docking study. In summary, the newly developed furan-derived chalcones and their ∆2-pyrazoline derivatives could serve as potent leads toward the development of novel antimicrobial agents.

Biological Potential and Bioaccessibility of Encapsulated Curcumin into Cetyltrimethylammonium Bromide Modified Cellulose Nanocrystals

Curcumin is a natural phenolic compound with important biological functions. Despite its demonstrated efficacy in vitro, curcumin biological activities in vivo are dependent on its bioaccessibility and bioavailability, which have been highlighted as a crucial challenge. Cetyltrimethylammonium bromide-modified cellulose nanocrystals (CNC-CTAB) have been shown to be effective in curcumin encapsulation, as they have the potential to enhance biological outcomes. This study evaluated the biological effects of curcumin encapsulated within CNC-CTAB structures, namely its antioxidant, anti-inflammatory and antimicrobial properties, as well as the release profile under digestion conditions and intestinal permeability. Encapsulated curcumin demonstrated antioxidant and anti-inflammatory properties, effectively reducing reactive oxygen species and cytokine production by intestinal cells. The delivery system exhibited antimicrobial properties against Campylobacter jejuni bacteria, further suggesting its potential in mitigating intestinal inflammation. The system showed the ability to protect curcumin from degradation and facilitate its interaction with the intestinal epithelium, highlighting the potential of CNC-CTAB as carrier to enhance curcumin intestinal biological functions.

Effects of Roasting Conditions on Antibacterial Properties of Vietnamese Turmeric (Curcuma longa) Rhizomes

Processing with heat treatment has been reported to alter several therapeutic effects of turmeric. In Vietnamese traditional medicine, turmeric has been long used for bacterial infections, and roasting techniques are sometimes applied with this material. However, there have been no studies investigating the effects of these thermal processes on the plant's antibacterial properties. Our study was therefore performed to examine the changes that roasting produced on this material. Slices of dried turmeric were further subjected to light-roasting (80 °C in 20 min) or dark-roasting (160 °C in 20 min) processes. Broth dilution and agar-well diffusion methods were applied to examine and compare the effects of ethanol extracts obtained from non-roasted, light-roasted and dark-roasted samples, on a set of 6 gram-positive and gram-negative bacteria. In both investigations, dark-roasted turmeric was significantly less antibacterial than non-roasted and light-roasted materials, as evident by the higher values of minimum inhibitory concentrations and the smaller diameters of induced inhibitory zones. In addition, dark-roasting was also found to clearly reduce curcumin contents, total polyphenol values and antioxidant activities of the extracts. These results suggest that non-roasting or light-roasting might be more suitable for the processing of turmeric materials that are aimed to be applied for bacterial infections.

Curcumin I-SMA nanomicelles as promising therapeutic tool to tackle bacterial infections

Renewed interest towards natural substances has been pushed by the widespread diffusion of antibiotic resistance. Curcumin I is the most active and effective constituent of curcuminoids extracted from Curcuma longa and, among other beneficial effects, attracted attention for its antimicrobial potential. Since the poor pharmacokinetic profile hinders its efficient utilization, in the present paper, we report encapsulation of curcumin I in poly(styrene-co-maleic acid) (SMA-CUR) providing a nanomicellar system with improved aqueous solubility and bioavailability. SMA-CUR was characterized by means of size, zeta potential, polydispersity index, atomic force microscopy (AFM), drug release studies, spectroscopic properties and stability. SMA-CUR nanoformulation displayed exciting antimicrobial properties compared to free curcumin I towards Gram-positive and Gram-negative clinical isolates.

A curcumin-nicotinoyl derivative and its transition metal complexes: synthesis, characterization, and in silico and in vitro biological behaviors

Curcumin-nicotinoyl (Cur-Nic) was synthesized by the chemical modification of the curcumin structure, characterized, and used as a ligand for the synthesis of copper(II) and zinc(II) complexes. The biological activities of Cur-Nic and its metal complexes were predicted using the PASS and Swiss Target Prediction online software, respectively, and docking studies with tyrosine-protein kinase SRC were performed using the PyRx software to predict their anticancer activities. The toxicity effects of the complexes on a human breast cancer cell line (MCF-7) compared to a healthy breast cell line (MCF-10A) were investigated by the MTS assay. Although the metal complexes maintained the least toxicity against normal cells, the results indicated that compared to curcumin and Cur-Nic, the cytotoxicity toward cancer cells increased due to the complexation process. Moreover, the antibacterial evaluation of the compounds against a Gram-positive bacterium (MRSA) and a Gram-negative bacterium (E. coli) indicated that the Cu(II) complex and Cur-Nic were the best, respectively. Also, the Zn(II) complex was the most stable compound, and the Cu(II) complex was the best ROS scavenger based on the in vitro evaluation.

Curcumin-loaded chitosan nanoparticles alleviate fenpropathrin-induced hepatotoxicity by regulating lipogenesis and pyroptosis in rats

In this study, the probable alleviative role of curcumin (CMN) (50 mg/kg b.wt) or curcumin-loaded chitosan nanoparticle (CLC-NP) (50 mg/kg b.wt) was assessed against the hepatotoxic effect of a widely used pyrethroid insecticide, fenpropathrin (FEN) (15 mg/kg b.wt) in rats in a 60-day experiment. The results revealed that CMN and CLC-NP significantly suppressed the FEN-induced increment in serum hepatic enzyme activities (ALT, AST, and ALP) and hyperbilirubinemia. Moreover, FEN-associated dyslipidemia, hepatic oxidative stress, and altered hepatic histology were significantly rescued by CMN and CLC-NP. Furthermore, the increased TNF-α and Caspase-3 immunoexpression in hepatic tissues of FEN-exposed rats was significantly reduced in CMN and CLC-NP-treated ones. FEN exposure significantly upregulated the pyroptosis-related genes, including GSDMD, Casp-1, Casp-3, Casp-8, IL-18, TNF-α, IL-1β, and NF-κB and altered the expression of lipogenesis-related genes including SREBP-1c, PPAR-α, MCP1, and FAS in the hepatic tissues. Nevertheless, the earlier disturbances in gene expression were corrected in CMN and CLC-NP-treated groups. Of note, compared to CMN, CLC-NP was more effective at inhibiting oxidative damage and controlling lipogenesis and pyroptosis in the hepatic tissues of FEN-exposed rats. Conclusively, the current study findings proved the superior and useful role of CLC-NP in combating pollutants associated with hepatic dysfunction.

Review: The Chemistry, Toxicity and Antibacterial Activity of Curcumin and Its Analogues

Antimicrobial resistance is a global challenge that is already exacting a heavy price both in terms of human health and financial cost. Novel ways of approaching this crisis include the investigation of natural products. Curcumin is the major constituent in turmeric, and it is commonly used in the preparation of Asian cuisine. In addition, it possesses a wide range of pharmacological properties. This review provides a detailed account of curcumin and its analogues' antibacterial activity against both gram-positive and gram-negative isolates, including its potential mechanism(s) of action and the safety and toxicity in human and animal models. We also highlight the key challenges in terms of solubility/bioavailability associated with the use of curcumin and include research on how these challenges have been overcome.

Antimicrobial Properties of Capsaicin: Available Data and Future Research Perspectives

Capsaicin is a phytochemical derived from plants of the genus Capsicum and subject of intensive phytochemical research due to its numerous physiological and therapeutical effects, including its important antimicrobial properties. Depending on the concentration and the strain of the bacterium, capsaicin can exert either bacteriostatic or even bactericidal effects against a wide range of both Gram-positive and Gram-negative bacteria, while in certain cases it can reduce their pathogenicity by a variety of mechanisms such as mitigating the release of toxins or inhibiting biofilm formation. Likewise, capsaicin has been shown to be effective against fungal pathogens, particularly Candida spp., where it once again interferes with biofilm formation. The parasites Toxoplasma gondi and Trypanosoma cruzi have been found to be susceptible to the action of this compound too while there are also viruses whose invasiveness is significantly dampened by it. Among the most encouraging findings are the prospects for future development, especially using new formulations and drug delivery mechanisms. Finally, the influence of capsaicin in somatostatin and substance P secretion and action, offers an interesting array of possibilities given that these physiologically secreted compounds modulate inflammation and immune response to a significant extent.

The food and biomedical applications of curcumin-loaded electrospun nanofibers: A comprehensive review

Encapsulating curcumin (CUR) in nanocarriers such as liposomes, polymeric micelles, silica nanoparticles, protein-based nanocarriers, solid lipid nanoparticles, and nanocrystals could be efficient for a variety of industrial and biomedical applications. Nanofibers containing CUR represent a stable polymer-drug carrier with excellent surface-to-volume ratios for loading and cell interactions, tailored porosity for controlled CUR release, and diverse properties that fit the requirements for numerous applications. Despite the mentioned benefits, electrospinning is not capable of producing fibers from multiple polymers and biopolymers, and the product's effectiveness might be affected by various machine- and material-dependent parameters like the voltage and the flow rate of the electrospinning process. This review delves into the current and innovative recent research on nanofibers containing CUR and their various applications.

Clinical and Radiographic Evaluation of Various Herbal Products Used with Zinc Oxide as an Obturating Material in Primary Teeth: An In Vivo Study

AIM

To compare the clinical and radiographically mixture of zinc oxide with Aloe vera, Curcumin and neem as an obturating material for pulpectomy.

MATERIALS AND METHODS

The study comprised of age group 4-8 years children requiring endodontic treatment for at least a single primary molar tooth. Sixty primary molar teeth from 43 children were divided equally and randomly into four study groups. The materials used for obturation were zinc oxide powder (ZnO) and Eugenol (ZOE) (group I), ZnO and Aloe vera Gel (group II), ZnO and Curcumin Powder (group III), ZnO and neem extract (group IV). They were evaluated clinically and radiographically at immediate postoperative and then at 1-, 3-, 6-, and 9-month intervals.

RESULTS

At the end of 9 months, the Chi-square test revealed 100% success rate for recovery of pain in group I and III, 66.66% in group II and 93.3% in group IV. The success rates for absence of abscess and for periradicular radiolucency in group I, III, and group IV were 100% and 66.6% for group II. The success rate for periapical radiolucency in group I and group III was 100%, in group II 66.6% and in group IV 93.35%. The success rate for all the groups shows 100% success in terms of pathological root resorption.

CONCLUSION

Zinc oxide eugenol has proven to be the best obturating material. ZnO with Aloe vera showed a success rate which is significantly lower than the other medicaments. ZnO with Curcumin and ZnO with neem had shown promising clinical and radiographical results.

CLINICAL SIGNIFICANCE

ZnO with Curcumin and ZnO with neem can be used as a root canal filling material in primary teeth with further follow-up studies.

Nanocurcumin and viable Lactobacillus plantarum based sponge dressing for skin wound healing

Curcumin loaded solid lipid nanoparticles (CSLNs) and probiotic (Lactobacillus plantarum UBLP-40; L. plantarum) were currently co-incorporated into a wound dressing. The combination with manifold anti-inflammatory, anti-infective, analgesic, and antioxidant properties of both curcumin and L. plantarum will better manage complex healing process. Recent reports indicate that polyphenolics like curcumin improve probiotic effects. Curcumin was nanoencapsulated (CSLNs) to improve its bioprofile and achieve controlled release on the wound bed. Bacteriotherapy (probiotic) is established to promote wound healing via antimicrobial activity, inhibition of pathogenic toxins, immunomodulation, and anti-inflammatory actions. Combination of CSLNs with probiotic enhanced (560%) its antimicrobial effects against planktonic cells and biofilms of skin pathogen, Staphylococcus aureus 9144. The sterile dressing was devised with selected polymers, and optimized for polymer concentration, and dressing characteristics using a central composite design. It exhibited a swelling ratio of 412 ± 36%, in vitro degradation time of 3 h, optimal water vapor transmission rate of 1516.81 ± 155.25 g/m2/day, high tensile strength, low-blood clotting index, case II transport, and controlled release of curcumin. XRD indicated strong interaction between employed polymers. FESEM revealed a porous sponge like meshwork embedded with L. plantarum and CSLNs. It degraded and released L. plantarum, which germinated in the wound bed. The sponge was stable under refrigerated conditions for up to six months. No translocation of probiotic from wound to the internal organs confirmed safety. The dressing exhibited faster wound closure and lowered bioburden in the wound area in mice. This was coupled with a decrease in TNF-α, MMP-9, and LPO levels; and an increase in VEGF, TGF-β, and antioxidant enzymes such as catalase and GSH, establishing multiple healing pathways. Results were compared with CSLNs and probiotic-alone dressings. The dressing was as effective as the silver nanoparticle-based marketed hydrogel dressing; however, the cost and risk of developing resistance would be much lower currently.

Optimization of FDM 3D printing process parameters to produce haemodialysis curcumin-loaded vascular grafts

3D printing has provided a new prospective in the manufacturing of personalized medical implants, including fistulas for haemodialysis (HD). In the current study, an optimized fused modelling deposition (FDM) 3D printing method has been validated, for the first time, to obtain cylindrical shaped fistulas. Printing parameters were evaluated for the manufacturing of fistulas using blank and 0.25% curcumin-loaded filaments that were produced by hot melt extrusion (HME). Four different fistula types have been designed and characterized using a variety of physicochemical characterization methods. Each design was printed three times to demonstrate printing process accuracy considering outer and inner diameter, wall thickness, width, and length. A thermoplastic polyurethane (TPU) biocompatible elastomer was chosen, showing good mechanical properties with a high elastic modulus and maximum elongation, as well as stability at high temperatures with less than 0.8% of degradation at the range between 25 and 250 °C. Curcumin release profile has been evaluated in a saline buffer, obtaining a low release (12%) and demonstrating drug could continue release for a longer period, and for as long as grafts should remain in patient body. Possibility to produce drug-loaded grafts using one-step method as well as 3D printing process and TPU filaments containing curcumin printability has been demonstrated.

Structure Property Relationship of Micellar Waterborne Poly(Urethane-Urea): Tunable Mechanical Properties and Controlled Release Profiles with Amphiphilic Triblock Copolymers

Waterborne polyurethane (WPU) has attracted significant interest as a promising alternative to solvent-based polyurethane (SPU) due to its positive impact on safety and sustainability. However, significant limitations of WPU, such as its weaker mechanical strength, limit its ability to replace SPU. Triblock amphiphilic diols are promising materials to enhance the performance of WPU due to their well-defined hydrophobic-hydrophilic structures. Yet, our understanding of the relationship between the hydrophobic-hydrophilic arrangements of triblock amphiphilic diols and the physical properties of WPU remains limited. In this study, we show that by controlling the micellar structure of WPU in aqueous solution via the introduction of triblock amphiphilic diols, the postcuring efficiency and the resulting mechanical strength of WPU can be significantly enhanced. Small-angle neutron scattering confirmed the microstructure and spatial distribution of hydrophilic and hydrophobic segments in the engineered WPU micelles. In addition, we show that the control of the WPU micellar structure through triblock amphiphilic diols renders WPU attractive in the applications of controlled release, such as drug delivery. Here, curcumin was used as a model hydrophobic drug, and the drug release behavior from WPU-micellar-based drug delivery systems was characterized. It was found that curcumin-loaded WPU drug delivery systems were highly biocompatible and exhibited antibacterial properties in vitro. Furthermore, the sustained release profile of the drug was found to be dependent on the structure of the triblock amphiphilic diols, suggesting the possibility of controlling the drug release profile via the selection of triblock amphiphilic diols. This work shows that by shedding light on the structure-property relationship of triblock amphiphilic diol-containing WPU micelles, we may enhance the applicability of WPU systems and move closer to realizing their promising potential in real-life applications.

Natural photosensitizer-loaded in micellar copolymer to prevent bovine mastitis: A new post-dipping protocol on milking

Good management practices such as post-dipping applications (post-milking immersion bath) contribute to the dairy cattle health during lactation and minimize the appearance of mastitis (an infection in the mammary gland). The post-dipping procedure is performed conventionally using iodine-based solutions. The search for therapeutic modalities that are not invasive and do not cause resistance to the microorganisms that cause bovine mastitis instigates the interest of the scientific community. In this regard, antimicrobial Photodynamic Therapy (aPDT) is highlighted. The aPDT is based on combining a photosensitizer (PS) compound, light of adequate wavelength, and molecular oxygen (3O2), which triggers a series of photophysical processes and photochemical reactions that generate reactive oxygen species (ROS) responsible for the inactivation of microorganisms. The present investigation explored the photodynamic efficiency of two natural PS: Chlorophyll-rich spinach extract (CHL) and Curcumin (CUR), both incorporated into the Pluronic® F127 micellar copolymer. They were applied in post-dipping procedures in two different experiments. The photoactivity of formulations mediated through aPDT was conducted against Staphylococcus aureus, and obtained a minimum inhibitory concentration (MIC) of 6.8 mg mL-1 for CHL-F127 and 0.25 mg mL-1 for CUR-F127. Only CUR-F127 inhibited Escherichia coli growth with MIC 0.50 mg mL-1. Concerning the count of microorganisms during the days of the application, a significant difference was observed between the treatments and control (Iodine) when the teat surface of cows was evaluated. For CHL-F127 there was a difference for Coliform and Staphylococcus (p < 0.05). For CUR-F127 there was a difference for aerobic mesophilic and Staphylococcus (p < 0.05). Such application decreased bacterial load and maintained the milk quality, being evaluated via total microorganism count, physical-chemical composition, and somatic cell count (SCC).

Therapeutic potential and limitations of curcumin as antimetastatic agent

Treatment of metastatic cancer is one of the biggest challenges in anticancer therapy. Curcumin is interesting nature polyphenolic compound with unique biological and medicinal effects, including repression of metastases. High impact studies imply that curcumin can modulate the immune system, independently target various metastatic signalling pathways, and repress migration and invasiveness of cancer cells. This review discusses the potential of curcumin as an antimetastatic agent and describes potential mechanisms of its antimetastatic activity. In addition, possible strategies (curcumin formulation, optimization of the method of administration and modification of its structure motif) to overcome its limitation such as low solubility and bioactivity are also presented. These strategies are discussed in the context of clinical trials and relevant biological studies.

Curcumin and Its Derivatives as Potential Antimalarial and Anti-Inflammatory Agents: A Review on Structure-Activity Relationship and Mechanism of Action

Curcumin, one of the major ingredients of turmeric (Curcuma longa), has been widely reported for its diverse bioactivities, including against malaria and inflammatory-related diseases. However, curcumin's low bioavailability limits its potential as an antimalarial and anti-inflammatory agent. Therefore, research on the design and synthesis of novel curcumin derivatives is being actively pursued to improve the pharmacokinetic profile and efficacy of curcumin. This review discusses the antimalarial and anti-inflammatory activities and the structure-activity relationship (SAR), as well as the mechanisms of action of curcumin and its derivatives in malarial treatment. This review provides information on the identification of the methoxy phenyl group responsible for the antimalarial activity and the potential sites and functional groups of curcumin for structural modification to improve its antimalarial and anti-inflammatory actions, as well as potential molecular targets of curcumin derivatives in the context of malaria and inflammation.

Therapeutic potential of curcumin in ARDS and COVID-19

Curcumin is a safe, non-toxic, readily available and naturally occurring compound, an active constituent of Curcuma longa (turmeric). Curcumin could potentially treat diseases, but faces poor physicochemical and pharmacological characteristics. To overcome these limitations, we developed a stable, water-soluble formulation of curcumin called cyclodextrin-complexed curcumin (CDC). We have previously shown that direct delivery of CDC to the lung following lipopolysaccharides exposure reduces acute lung injury (ALI) and effectively reduces lung injury, inflammation and mortality in mice following Klebsiella pneumoniae. Recently, we found that administration of CDC led to a significant reduction in angiotensin-converting enzyme 2 and signal transducer and activator of transcription 3 expression in gene and protein levels following pneumonia, indicating its potential in treating coronavirus disease 2019 (COVID-19). In this review, we consider the clinical features of ALI and acute respiratory distress syndrome (ARDS) and the role of curcumin in modulating the pathogenesis of bacterial/viral-induced ARDS and COVID-19.

Functionalization of curcumin nanomedicines: a recent promising adaptation to maximize pharmacokinetic profile, specific cell internalization and anticancer efficacy against breast cancer

Owing to its diverse heterogeneity, aggressive nature, enormous metastatic potential, and high remission rate, the breast cancer (BC) is among the most prevalent types of cancer associated with high mortality. Curcumin (Cur) is a potent phytoconstituent that has gained remarkable recognition due to exceptional biomedical viability against a wide range of ailments including the BC. Despite exhibiting a strong anticancer potential, the clinical translation of Cur is restricted due to intrinsic physicochemical properties such as low aqueous solubility, chemical instability, low bioavailability, and short plasma half-life. To overcome these shortcomings, nanotechnology-aided developments have been extensively deployed. The implication of nanotechnology has pointedly improved the physicochemical properties, pharmacokinetic profile, cell internalization, and anticancer efficacy of Cur; however, majority of Cur-nanomedicines are still facing grandeur challenges. The advent of various functionalization strategies such as PEGylation, surface decoration with different moieties, stimuli-responsiveness (i.e., pH, light, temperature, heat, etc.), tethering of specific targeting ligand(s) based on the biochemical targets (e.g., folic acid receptors, transferrin receptors, CD44, etc.), and multifunctionalization (multiple functionalities) has revolutionized the fate of Cur-nanomedicines. This study ponders the biomedical significance of various Cur-nanomedicines and adaptable functionalizations for amplifying the physicochemical properties, cytotoxicity via induction of apoptosis, cell internalization, bioavailability, passive and active targeting to the tumor microenvironment (TME), and anticancer efficacy of the Cur while reversing the multidrug resistance (MDR) and reoccurrence in BC. Nevertheless, the therapeutic outcomes of Cur-nanomedicines against the BC have been remarkably improved after adaptation of various functionalizations; however, this evolving strategy still demands extensive research for scalable clinical translation.

An Analysis of the Toxicity, Antioxidant, and Anti-Cancer Activity of Cinnamon Silver Nanoparticles in Comparison with Extracts and Fractions of Cinnamomum Cassia at Normal and Cancer Cell Levels

In this work, the extract of cinnamon bark was used for the green synthesis of cinnamon-Ag nanoparticles (CNPs) and other cinnamon samples, including ethanolic (EE) and aqueous (CE) extracts, chloroform (CF), ethyl acetate (EF), and methanol (MF) fractions. The polyphenol (PC) and flavonoid (FC) contents in all the cinnamon samples were determined. The synthesized CNPs were tested for the antioxidant activity (as DPPH radical scavenging percentage) in Bj-1 normal cells and HepG-2 cancer cells. Several antioxidant enzymes, including biomarkers, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and reduced glutathione (GSH), were verified for their effects on the viability and cytotoxicity of normal and cancer cells. The anti-cancer activity depended on apoptosis marker protein levels (Caspase3, P53, Bax, and Pcl2) in normal and cancerous cells. The obtained data showed higher PC and FC contents in CE samples, while CF showed the lowest levels. The IC₅₀ values of all investigated samples were higher, while their antioxidant activities were lower than those of vitamin C (5.4 g/mL). The CNPs showed lower IC₅₀ value (55.6 µg/mL), whereas the antioxidant activity inside or outside the Bj-1 or HepG-2 was found to be higher compared with other samples. All samples execrated a dose-dependent cytotoxicity by decreasing the cells' viability percent of Bj-1 and HepG-2. Similarly, the anti-proliferative potency of CNPs on Bj-1 or HepG-2 at different concentrations was more effective than that of other samples. Higher concentrations of the CNPs (16 g/mL) showed greater cell death in Bj-1 (25.68%) and HepG-2 (29.49%), indicating powerful anti-cancer properties of the nanomaterials. After 48 h of CNPs treatment, both Bj-1 and HepG-2 showed significant increases in biomarker enzyme activities and reduced glutathione compared with other treated samples or untreated controls (p < 0.05). The anti-cancer biomarker activities of Caspas-3, P53, Bax, and Bcl-2 levels were significantly changed in Bj-1 or HepG-2 cells. The cinnamon samples were significantly increased in Caspase-3, Bax, and P53, while there were decreased Bcl-2 levels compared with control.

MRSA compendium of epidemiology, transmission, pathophysiology, treatment, and prevention within one health framework

Staphylococcus aureus is recognized as commensal as well as opportunistic pathogen of humans and animals. Methicillin resistant strain of S. aureus (MRSA) has emerged as a major pathogen in hospitals, community and veterinary settings that compromises the public health and livestock production. MRSA basically emerged from MSSA after acquiring SCCmec element through gene transfer containing mecA gene responsible for encoding PBP-2α. This protein renders the MRSA resistant to most of the β-lactam antibiotics. Due to the continuous increasing prevalence and transmission of MRSA in hospitals, community and veterinary settings posing a major threat to public health. Furthermore, high pathogenicity of MRSA due to a number of virulence factors produced by S. aureus along with antibiotic resistance help to breach the immunity of host and responsible for causing severe infections in humans and animals. The clinical manifestations of MRSA consist of skin and soft tissues infection to bacteremia, septicemia, toxic shock, and scalded skin syndrome. Moreover, due to the increasing resistance of MRSA to number of antibiotics, there is need to approach alternatives ways to overcome economic as well as human losses. This review is going to discuss various aspects of MRSA starting from emergence, transmission, epidemiology, pathophysiology, disease patterns in hosts, novel treatment, and control strategies.

Preparation of zein/chitosan/eugenol/curcumin active films for blueberry preservation

This study aimed to develop zein/chitosan-based films formulated with curcumin and eugenol to improve the quality of postharvest blueberries. First, the film-forming solutions were characterized (rheological property and water distribution), and the mechanical, structural properties and bioactivity of active films fabricated by casting were evaluated. Further, the active film was coated with blueberry stored at 4 °C, and physicochemical properties (weight loss, hardness, microbial counts, and appearance changes) were measured. The film-forming solutions exhibited non-Newtonian behavior. The incorporation of curcumin and eugenol improved the tensile strength and elongation at the break of films, reaching 17.86 MPa and 92.80 %, respectively. The antioxidant capacity was enhanced, and DPPH and ABTS radical scavenging rates were up to 90.60 ± 0.06 % and 86.34 ± 0.39 %, respectively. Meanwhile, the prepared active films possessed good anti-UV and sensitive pH-response color-shifting ability. Compared to the uncoated blueberry, blueberry coated with zein/chitosan/curcumin/eugenol showed lower weight loss and higher hardness, indicating that the prepared active films played a vital role in delaying the deterioration of blueberry and extending its shelf life. Overall, the zein-chitosan incorporated with curcumin and eugenol films could be a promising candidate to prolong the shelf life of food products due to their excellent bioactive capacity.

Formulation, Characterization and Evaluation of Innovative O/W Emulsions Containing Curcumin Derivatives with Enhanced Antioxidant Properties

In the present study, a series of semisolid Oil in Water (O/W) emulsions containing different Curcumin (Cur) derivatives (Cur powder, Cur extract and Cur complexed with β-cyclodextrin) in varying concentrations, were prepared. Initially, Dynamic Light Scattering (DLS), microscopy, pH and viscosity measurements were performed to evaluate their stability over time. Moreover, the effect of the active cosmetic substances on the Sun Protection Factor (SPF), antimicrobial and antioxidant properties of the prepared emulsions was investigated. It was observed that emulsions containing Cur extract and Cur β-cyclodextrin complex presented great viscosity and pH stability for up to 90 days of storage contrary to the emulsions containing Cur powder which showed unstable behavior due to the formation of agglomerates. All samples presented SPF values between 2.6 and 3.2. The emulsions with Cur in all forms exhibited high antioxidant activity, whereas the emulsion containing Cur β-cyclodextrin complex presented the highest value. Despite their improved stability and antioxidant activity, the emulsions containing Cur extract and Cur-β-cyclodextrin exhibited a low percentage of antimicrobial activity against E. coli and Staphylococcus bacteria. Instead, the emulsions containing Cur powder presented a reduction rate over 90 % against E. coli and Staphylococcus colonies.

Terpenes as bacterial efflux pump inhibitors: A systematic review

Managing antibiotic resistance is a significant challenge in modern pharmacotherapy. While molecular analyses have identified efflux pump expression as an essential mechanism underlying multidrug resistance, the targeted drug development has occurred slower. Thus, considering the verification that terpenes can enhance the activity of antibiotics against resistant bacteria, the present study gathered evidence pointing to these natural compounds as bacterial efflux pump inhibitors. A systematic search for manuscripts published between January 2007 and January 2022 was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and the following search terms: “Terpene”; AND “Efflux pump”; and “Bacteria.” From a total of 101 articles found in the initial search, 41 were included in this review. Seventy-five different terpenes, 63 bacterial strains, and 22 different efflux pumps were reported, with carvacrol, Staphylococcus aureus SA-1199B, and NorA appearing most frequently mentioned terpene, bacterial strain, and efflux pump (EP), respectively. The Chi-Squared analysis indicated that terpenes are significantly effective EP inhibitors in Gram-positive and Gram-negative strains, with the inhibitory frequency significantly higher in Gram-positive strains. The results of the present review suggest that terpenes are significant efflux pump inhibitors and, as such, can be used in drug development targeting the combat of antibacterial resistance.

Cocktail of isobavachalcone and curcumin enhance eradication of Staphylococcus aureus biofilm from orthopedic implants by gentamicin and alleviate inflammatory osteolysis

Orthopedic device-related infection (ODRI) caused by Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA) biofilm may lead to persist infection and severe inflammatory osteolysis. Previous studies have demonstrated that both isobavachalcone and curcumin possess antimicrobial activity, recent studies also reveal their antiosteoporosis, anti-inflammation, and immunoregulatory effect. Thus, this study aims to investigate whether the combination of isobavachalcone and curcumin can enhance the anti-S. aureus biofilm activity of gentamicin and alleviate inflammatory osteolysis in vivo. EUCAST and a standardized MBEC assay were used to verify the synergy between isobavachalcone and curcumin with gentamicin against planktonic S. aureus and its biofilm in vitro, then the antimicrobial and immunoregulatory effect of cocktail therapy was demonstrated in a femoral ODRI mouse model in vivo by μCT analysis, histopathology, quantification of bacteria in bone and myeloid-derived suppressor cell (MDSC) in bone marrow. We tested on standard MSSA ATCC25923 and MRSA USA300, 5 clinical isolated MSSA, and 2 clinical isolated MRSA strains and found that gentamicin with curcumin (62.5–250 μg/ml) and gentamicin with isobavachalcone (1.56 μg/ml) are synergistic against planktonic MSSA, while gentamicin (128 μg/ml) with curcumin (31.25–62.5, 250–500 μg/ml) and gentamicin (64–128 μg/ml) with isobavachalcone (1.56–12.5 μg/ml) exhibit synergistic effect against MSSA biofilm. Results of further study revealed that cocktail of 128 μg/ml gentamicin together with 125 μg/ml curcumin +6.25 μg/ml isobavachalcone showed promising biofilm eradication effect with synergy against USA300 biofilm in vitro. Daily intraperitoneal administration of 20 mg/kg/day isobavachalcone, 20 mg/kg/day curcumin, and 20 mg/kg/day gentamicin, can reduce inflammatory osteolysis and maintain microarchitecture of trabecular bone during orthopedic device-related MRSA infection in mice. Cocktail therapy also enhanced reduction of MDSC M1 polarization in peri-implant tissue, suppression of MDSC amplification in bone marrow, and Eradication of USA300 biofilm in vivo. Together, these results suggest that the combination of isobavachalcone and curcumin as adjuvants administrated together with gentamicin significantly enhances its antimicrobial effect against S. aureus biofilm, and can also modify topical inflammation in ODRI and protect bone microstructure in vivo, which may serve as a potential treatment strategy, especially for S. aureus induced ODRI.

Curcumin Stimulates the Overexpression of Virulence Factors in Salmonella enterica Serovar Typhimurium: In Vitro and Animal Model Studies

Salmonella spp. is one of the most common food poisoning pathogens and the main cause of diarrheal diseases in humans in developing countries. The increased Salmonella resistance to antimicrobials has led to the search for new alternatives, including natural compounds such as curcumin, which has already demonstrated a bactericidal effect; however, in Gram-negatives, there is much controversy about this effect, as it is highly variable. In this study, we aimed to verify the antibacterial activity of curcumin against the Salmonella enterica serovar Typhimurium growth rate, virulence, and pathogenicity. The strain was exposed to 110, 220 or 330 µg/mL curcumin, and by complementary methods (spectrophotometric, pour plate and MTT assays), we determined its antibacterial activity. To elucidate whether curcumin regulates the expression of virulence genes, Salmonella invA, fliC and siiE genes were investigated by quantitative real-time reverse transcription (qRT-PCR). Furthermore, to explore the effect of curcumin on the pathogenesis process in vivo, a Caenorhabditis elegans infection model was employed. No antibacterial activity was observed, even at higher concentrations of curcumin. All concentrations of curcumin caused overgrowth (35−69%) and increased the pathogenicity of the bacterial strain through the overexpression of virulence factors. The latter coincided with a significant reduction in both the lifespan and survival time of C. elegans when fed with curcumin-treated bacteria. Our data provide relevant information that may support the selective antibacterial effects of curcumin to reconsider the indiscriminate use of this phytochemical, especially in outbreaks of pathogenic Gram-negative bacteria.

Fabrication of Curcumin-Loaded Silk Fibroin and Polyvinyl Alcohol Composite Hydrogel Films for Skin Wound Healing

Skin regeneration of full-thickness wounds remains a challenge, requiring a well-regulated interplay of cell-cell and cell-matrix signaling. Herein, the composite hydrogel films composed of silk fibroin (SF) and polyvinyl alcohol (PVA) as scaffolds loaded with curcumin nanoparticles (Cur NPs) were developed for skin wound healing. The structure and physicochemical properties of hydrogel films were first evaluated by scanning electron microscopy (SEM), water contact angle, and chemical and mechanical measurements. In addition, the as-fabricated composite hydrogel films have a unique 3D structure and excellent biocompatibility that facilitates the adhesion and growth of cells. Antimicrobial tests in vitro showed that they could inhibit the growth of bacteria due to the incorporation of Cur NPs into composite hydrogel films. The efficacy of the curcumin-loaded SF/PVA composite hydrogel films for skin wound healing was investigated on the skin defect model in vivo. Immunological analysis showed that the as-fabricated Cur NP-loaded SF/PVA composite hydrogel films inhibited inflammation at the wound sites, while promoting angiogenesis during the wound healing process.

Vitamin D and curcumin-loaded PCL nanofibrous for engineering osteogenesis and immunomodulatory scaffold

The accelerating bone healing process is still a major challenge in clinical orthopedics, especially in critical-sized bone defects. Recently, Nanofiber membranes are showing increasing attention in the biomedical field due to their good biocompatibility, mechanical stability, and the ability to work as a drug carrier to achieve localized and sustained drug delivery. Herein, a multifunction nanofiber membrane loaded with vitamin D (Vit D) and curcumin (Cur) was successfully fabricated using electrospinning technology. In addition, we innovatively modified Vit D with PEG to improve the hydrophilicity of PCL nanofibers. The vitro results of CCK-8, alkaline phosphatase (ALP) and mineralization demonstrated that the PCL/Vit D-Cur membrane had great potential for enhancing the proliferation/differentiation of osteoblasts. Moreover, the synergistic effect of Vit D-Cur loaded PCL nanofiber membrane showed a superior ability to improve the anti-inflammatory activity through M2 polarization. Furthermore, in vivo results confirmed that the defect treated with PCL/Vit D-Cur nanofiber membrane was filled with the newly formed bone after 1 month. These results indicate that the Vit D/Cur loaded membrane can be applied for potential bone regeneration therapy.

Comparative Toxicity of Vegan Red, E124, and E120 Food Dyes on Three Rapidly Proliferating Model Systems

The abuse of artificial food dyes and the evidence that they harm human health recently prompted a significant effort to introduce vegan substitutes prepared from fruits and vegetables. Not much information, however, has been collected on their possible effects on aquatic and terrestrial ecosystems once released as waste in surface waters. For this purpose, we analyzed the effects of a vegan red (VEG) preparation (concentration 1.2 g/L) on three rapidly proliferating models for terrestrial and aquatic ecosystem contamination. In particular, in vitro cells cultures (exposure for 24 h), Artemia salina nauplii and Cucumis sativus seedlings (exposure 5 days). A comparison was made with the effects exerted by the two dyes that vegan red is intended to replace: an animal dye, cochineal E120 and an artificial dye E124. The analyses of conventional endpoints, indicative of cell proliferation, differentiation, and growth rate, demonstrate that the three dyes affect development and that the vegan substitute is as unsafe as the E124 and E120. Vegan red in fact impairs cell growth in in vitro cells, delays naupliar hatching and early growth in Artemia, and reduces shoot/root biomass in Cucumis. Marked hyperplasia and hypertrophy of mesophyll are also observed in Cucumis leaves. Substitution in food and beverages, therefore, should be carefully reconsidered to avoid unnecessary environmental contamination.

In-Vitro Antibacterial Activity of Curcumin-Loaded Nanofibers Based on Hyaluronic Acid against Multidrug-Resistant ESKAPE Pathogens

Bacterial infections have accompanied humanity throughout its history and became vitally important in the pandemic area. The most pathogenic bacteria are multidrug-resistant strains, which have become widespread due to their natural biological response to the use of antibiotics, including uncontrolled use. The current challenge is finding highly effective antibacterial agents of natural origin, which, however, have low solubility and consequently poor bioavailability. Curcumin, derived from Curcuma longa, is an example of a natural biologically active agent with a wide spectrum of biological effects, particularly against Gram-positive bacteria. However, curcumin exhibits extremely low antibacterial activity against Gram-negative bacteria. Curcumin’s hydrophobicity limits its use in medicine. As such, various polymeric systems have been used, especially biopolymer-based electrospun nanofibers. In the present study, the technological features of the fabrication of curcumin-loaded hyaluronic acid-based nanofibers are discussed in detail, their morphological characteristics, wettability, physico-chemical properties, and curcumin release profiles are demonstrated, and their antibacterial activity against multi-drug resistant ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) are evaluated. It is noteworthy that the fibers containing a stable HA–curcumin complex showed high antibacterial activity against both Gram-positive and Gram-negative bacteria, which is an undeniable advantage. It is expected that the results of this work will contribute to the development of antibacterial drugs for topical and internal use with high efficacy and considerably lower side effects.

Efficacy of Selected Powdered Floor Treatments Against Salmonella, E. coli, and L. monocytogenes on Polyurethane-Concrete Flooring Material Carriers

Food processing environment flooring can become contaminated with pathogens in many ways including foot and equipment traffic, incoming materials, and floor drain backups.  Natural antimicrobial turmeric and commercially available powdered floor treatments may reduce the levels of pathogens on flooring thereby reducing the risk of cross contamination from the floor to food contact surfaces. These chemicals were evaluated to determine their effectiveness against cocktails of Salmonella , Escherichia coli , and Listeria monocytogenes dried onto the surfaces of carriers made from polyurethane-concrete commercial flooring material.  Aqueous test solutions were prepared from the minimum treatment required per m 2 from the manufacturer's instructions diluted in sterile water.  Potential synergy between turmeric and a percarbonate based commercial floor treatment was explored with a mixture of turmeric and sodium percarbonate, each at approximately 37g/m 2 application rate.  Each inoculated carrier was exposed to the treatment solutions or a sterile water control for 10 minutes at room temperature, neutralized with Hi-Cap neutralizing broth, the bacteria suspended, enumerated, and log 10 reductions calculated for each treatment and inoculum combination.  Mean log 10 CFU/carrier reductions with standard deviations ranged between 4.29±0.34 for the sodium percarbonate (SPC) based treatment and 0.004±0.23 for turmeric for Salmonella , 4.81±0.16 for SPC based treatment and -0.16±0.62 for turmeric for E. coli , and 4.88±0.6 for SPC based treatment and -0.16±0.15 for turmeric for L. monocytogenes .

Comparing deep eutectic solvents and cyclodextrin complexes as curcumin vehicles for blue-light antimicrobial photodynamic therapy approaches

Curcumin (Cur), a polyphenolic compound derived from Curcuma longa L., has garnered the attention of the scientific community due to its remarkable biological properties such as its potential as a photosensitizing agent for photodynamic therapy (PDT). However, due to its low solubility in aqueous media and instability at physiological and alkaline pH, Cur has struggled to find relevant clinical application. To tackle these shortcomings, two distinct Cur-based formulations based on either complexation with methyl-β-cyclodextrin (MβCD), MβCDC-Cur, or dissolution in a choline chloride (ChCl): glycerol (Gly) deep eutectic solvent (DES), DES-Cur, were produced, physio-chemically characterized and compared regarding their potential as phototherapeutic agents for blue-light antimicrobial photodynamic therapy (aPDT) approaches. Both MβCD-Cur and DES-Cur were able to greatly enhance Cur solubility profile when compared to Cur powder. However, MβCD-Cur appears to hinder some of Cur's basal biological properties and possessed greater basal cytotoxicity towards L929 murine fibroblast cell line. Furthermore, MβCD-Cur was less photo-responsive when exposed to light which may hamper its application in blue-light aPDT approaches. In contrast, DES-Cur showed good biological properties and high photoresponsivity, displaying relevant phototoxicity against bacterial pathogens (≥ 99.9% bacterial reduction) while being better tolerated by L929 murine cells. Overall, this study found DES to be the more effective vehicle for Cur in terms of phototherapeutic potential which will serve as basis to develop novel platforms and approaches for blue-light aPDT targeting localized superficial infections.

Characterization of virulence factors and antibacterial activity of curcumin in hypervirulent Klebsiella pneumoniae

Aim: Klebsiella pneumoniae is a threat to human health due to its carbapenem-resistance and hypervirulent phenotype. Curcumin is a well-known antimicrobial agent. Hence, it is important to investigate the antivirulence activity of curcumin against hypervirulent K. pneumoniae isolates. Materials & methods: Carbapenemase presence and prevalence of hypervirulent isolates were determined. Inhibition of biofilm formation and expression of virulence genes were analyzed by colorimetry and real-time PCR tests. Results: Sixteen hypervirulent K. pneumoniae isolates were identified. The optimum activity of curcumin was detected at 1/2 minimum inhibitory concentration. Curcumin possessed appropriate antibiofilm, anti-efflux and anticapsule activities. Conclusion: According to the crucial role of biofilm, capsule and efflux systems in the pathogenesis of hypervirulent K. pneumoniae, curcumin may be used to improve anti-Klebsiella treatment.

Gallium-Curcumin Nanoparticle Conjugates as an Antibacterial Agent against Pseudomonas aeruginosa: Synthesis and Characterization

Combating antibiotic resistance has found great interest in the current clinical scenario. Pseudomonas aeruginosa, an opportunistic multidrug-resistant pathogen, is well known for its deadly role in hospital-acquired infections. Infections by P. aeruginosa are among the toughest to treat because of its intrinsic and acquired resistance to antibiotics. In this study, we project gallium-curcumin nanoparticle (GaCurNP) conjugates as a prospective candidate to fight against P. aeruginosa. The synthesized GaCurNPs were spherical with an average size ranging from 25-35 nm. Analysis by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy deduced the nature of interaction between gallium and curcumin. Conjugate formation with gallium was found to improve the stability of curcumin at the physiological pH. When tested after 24 h of contact, at the physiological pH and 37 °C, the degradation of curcumin bound in the GaCurNPs was 26%, while that of native curcumin was 95%. The minimum inhibitory concentration (MIC) of GaCurNPs was found to be 82.75 μg/mL for P. aeruginosa (ATCC 27853). GaCurNPs also showed excellent biofilm inhibition at 4MIC concentration. Raman spectroscopic analysis showed that GaCurNPs are capable of disrupting the cells of P. aeruginosa within 3 h of contact. Live/dead imaging also confirmed the compromised membrane integrity in cells treated with GaCurNPs. Scanning electron microscopy analysis showed membrane lysis and cell structure damage. The AlamarBlue assay showed that when L929 cell lines were treated with GaCurNPs with concentrations as high as 350 μg/mL, the cell viability elicited by the nanoparticles was 70.89%, indicating its noncytotoxic nature. In short, GaCurNPs appear to be a promising antibacterial agent capable of fighting a clinically significant pathogen, P. aeruginosa.