Study on the antibiotic activity of microcapsule curcumin against foodborne pathogens

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.

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.

Study on synergistic effects of curcumin and bixin against foodborne pathogens

Various studies have shown that natural colorants, in addition to their coloring attributes, have valuable biological effects such as antioxidant, anti-inflammation, and anticarcinogenic properties. Moreover, their use as a food colorant can restrict the potential disadvantages of synthetic additives and turn foods into functional products. In this study, in vitro antimicrobial activities of two natural colorants of bixin and curcumin against some important foodborne pathogens: Staphylococcus aureus (S. aureus), Listeria innocua (L. innocua), and Escherichia coli (E. coli) were investigated by disk diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration values were determined by agar dilution and broth microdilution methods. The synergistic activity of the colorants against selected microorganisms was assayed by the checkerboard microdilution method. The results showed that the inhibitory effects of bixin against S. aureus were more pronounced than E. coli and L. innocua. The lowest concentration of curcumin (0.6 mg/mL) in the disk diffusion method was not inhibited by any tested bacteria. However, it was effective at the higher concentrations against three microorganisms, but its diameter of inhibition zones was lower than gentamicin in all concentrations. Synergetic effects were observed by curcumin and bixin combination against S. aureus (FICI ≤ 0.5), but they act as an antagonist against E. coli and L. innocua. The results of the synergy test were confirmed by the isobologram curves.

Preparation, stability, and antibacterial activity of carboxymethylated Anemarrhena asphodeloides polysaccharide-chitosan nanoparticles loaded curcumin

In present study, polysaccharide polyelectrolyte nanoparticles (CMAAP-CS NPs) were constructed by mixing carboxymethylated Anemarrhena asphodeloides polysaccharide (CMAAP) and chitosan (CS). CMAAP-CS NPs were applied as carrier to improve the bioavailability and stability of curcumin (Cur). The average particle size of CMAAP-CS NPs was 216.60 ± 4.21 nm and the entrapment efficiency of Cur reached 82.50 ± 2.09 %. The simulated digestion experiments in vitro confirmed that the bioavailability of Cur loaded in CMAAP-CS NPs was 59.84 ± 0.03 % after saliva, gastric and intestinal digestion, which was obvious higher than 21.57 ± 0.07 % of free Cur under the same conditions. The results of stability testing revealed that CMAAP-CS NPs could markedly reduce the degradation of Cur against storage, heating, UV light treatment, and neutral pH. This study provided promising polyelectrolyte complex loaded hydrophobic nutrients in medicine industry.

Photodynamic-responsive gelatin-based coating with high utilization curcumin loaded bilayer nanoencapsulation: A promising environmental food packaging

The development and application of curcumin-mediated antimicrobial photodynamic techniques (PDT) in food preservation are highly anticipated to resist microbial contamination and prevent food spoilage. In this study, high-utilization curcumin-loaded bilayer nanoencapsulation was prepared to incorporated into a gelatin-based edible coating for beef preservation. Bilayer nanoencapsulation composed of shellac and poly-γ-glutamic acid (CS-NPs) improved the encapsulation efficiency of shellac to curcumin by >1.5 times. The incorporation of CS-NPs improved the compact of coating structure with hydrogen bonds. In food simulants, coatings possessed control release properties and the release mechanism was Fick diffusion (without the addition of γ-PGA) and non-Fick diffusion (with the addition of γ-PGA). These prepared coatings exhibited excellent barrier, antibacterial (antibacterial ratio > 95 %), and antioxidant properties (scavenging ratio > 90 %). Curcumin mediated antimicrobial photodynamic techniques (PDT) of the coatings were verified with the activity of blue light-induced reactive oxygen species (ROS). The shelf-life of beef was extended by the coating with blue light. In summary, the design of bilayer CS-NPs significantly improved the utilization of curcumin which provided a high-efficiency strategy for PDT-responsive food packaging with environmental practical.

Biosorption of lead ion by lactic acid bacteria and the application in wastewater

Through the study of biosorption of Pb2+ by lactic acid bacteria, two strains called CN-011 and CN-005 with high tolerance and great adsorption to lead were screened. The minimum bactericidal concentration of lead ions for both CN-011 and CN-005 was 1.45 mmol/L. The optimal culture conditions for the removal of 30 mg/L lead ions were achieved by culturing lactic acid bacteria at an initial pH of 7.0, 37 °C and 120 rpm for 48 h. The adsorption rate of CN-011 and CN-005 for Pb2+ were 85.95% and 86.78%, respectively. In simulated wastewater samples, the average adsorption rate of Pb2+ was 73.38% for CN-011 and 74.15% for CN-005. The mechanism of biosorption was characterized by Fourier Transform infrared spectroscopy, Scanning Electron Microscope-Energy Dispersive Spectrometer, X-ray Photoelectron Spectroscopy, which revealed that Pb2+ mainly reacted with hydroxyl ions in peptidoglycan or polysaccharide, and carboxylate radical in teichoic acid or protein on the surface of lactic acid bacteria cell wall. The deposits produced on the bacterial surface were identified as lead oxide and lead nitrate.

Ultrasound assisted wall-breaking extraction and primary structures, bioactivities, rheological properties of novel Exidia yadongensis polysaccharide

New natural multifunctional polysaccharide and its innovatory extraction technology may be urgently needed for food industries. Our aims were to establish new extraction method and investigate the primary structures, bioactivities and rheological properties of novel E. yadongensis polysaccharide (EYP). Ultrasound assisted mechanical wall-breaking extraction (MAUE) was successfully established for the EYP extraction from a new E. yadongensis. Based on the MAUE with RSM, the polysaccharide yield of 17.92 ± 0.56 % with the optimal parameters of five extraction factors were obtained, and current MAUE was characterized by its high yield, low extraction temperature and short ultrasound time. After the isolation and purification, the EYP as a protein-bound polysaccharide was obtained. FT-IR and NMR analysis showed that the main backbone of the EYP comprised of (1 → 4)-β-D-glucopyranosyl and (1 → 6)-ɑ-D-mannopyranosyl groups; EYP exhibited significant antioxidant, antibacterial, antitumor, antidiabetic activities, and good viscoelastic properties in low pH solutions (P < 0.05). The EYP may be used as a natural functional and cohesive agent in food industries.

Analysis of the antibacterial effects of turmeric on particular bacteria

Antimicrobial properties of plants have been investigated by a number of studies worldwide and many of them have been used as therapeutic alternatives because of their antimicrobial properties. The quest for suitable and affordable alternative in the face of increasing antimicrobial drug resistant has led researchers into exploring the use of plant extract in the treatment of infections. The antibacterial properties of turmeric (Curcuma longa) on selected bacteria were evaluated. Different concentrations of turmeric extract (100, 50, 25, and 12.5 mg/mL) were prepared using 2 solvents namely water and ethanol. The antibacterial activity was tested against Bacillus species, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa at different concentration of the extract using disc diffusion method and ciprofloxacin was the control. The zones of inhibition exhibited by ethanol and aqueous extracts against test organisms ranged from 1 to 10 mm. the ethanolic extracts were more effective than the aqueous extracts exhibiting zones of inhibition ranging from 3 to 10 mm against Bacillus species, 4 to 9 mm against S aureus, and 1 to 7 mm against E coli. There was no inhibitory effect against P aeruginosa. There was significant difference between the ethanol and aqueous extracts (P < .05). This study reveal that Turmeric plant has antibacterial potential against selected organisms and may be of great use of pharmaceutical industries for the development of medicine to cure ailments and control abnormal serum lipid profile.

Current appraises of therapeutic applications of nanocurcumin: A novel drug delivery approach for biomaterials in dentistry

Curcumin is a natural herb and polyphenol that is obtained from the medicinal plant Curcuma longa. It's anti-bacterial, anti-inflammatory, anti-cancer, anti-mutagenic, antioxidant and antifungal properties can be leveraged to treat a myriad of oral and systemic diseases. However, natural curcumin has weak solubility, limited bioavailability and undergoes rapid degradation, which severely limits its therapeutic potential. To overcome these drawbacks, nanocurcumin (nCur) formulations have been developed for improved biomaterial delivery and enhanced treatment outcomes. This novel biomaterial holds tremendous promise for the treatment of various oral diseases, the majority of which are caused by dental biofilm. These include dental caries, periodontal disease, root canal infection and peri-implant diseases, as well as other non-biofilm mediated oral diseases such as oral cancer and oral lichen planus. A number of in-vitro studies have demonstrated the antibacterial efficacy of nCur in various formulations against common oral pathogens such as S. mutans, P. gingivalis and E. faecalis, which are strongly associated with dental caries, periodontitis and root canal infection, respectively. In addition, some clinical studies were suggestive of the notion that nCur can indeed enhance the clinical outcomes of oral diseases such as periodontitis and oral lichen planus, but the level of evidence was very low due to the small number of studies and the methodological limitations of the available studies. The versatility of nCur to treat a diverse range of oral diseases augurs well for its future in dentistry, as reflected by rapid pace in which studies pertaining to this topic are published in the scientific literature. In order to keep abreast of the latest development of nCur in dentistry, this narrative review was undertaken. The aim of this narrative review is to provide a contemporaneous update of the chemistry, properties, mechanism of action, and scientific evidence behind the usage of nCur in dentistry.

Physico-chemical properties of curcumin nanoparticles and its efficacy against Ehrlich ascites carcinoma

Curcumin is a bioactive component with anticancer characteristics; nevertheless, it has poor solubility and fast metabolism, resulting in low bioavailability and so restricting its application. Curcumin loaded in nano emulsions (Cur-NE) was developed to improve water solubility and eliminate all the limitations of curcumin. Size distribution, zeta potential, transmission electron microscopy (TEM) measurements, UV-Visible spectra, IR spectra and thermogravimetric analysis (TGA), were used to characterize the prepared Cur-NE. Cancer therapeutic efficacy was assessed by oxidative stress (superoxide dismutase (SOD), Glutathione-S-Transferase (GST), malondialdehyde (MDA) and nitric oxide (NO), DNA damage, apoptotic proteins (caspase-3 and 9), besides investigating tumor histology and monitoring tumor growth. Additionally, the cytotoxicity and genotoxicity of the liver, kidney, heart, and spleen tissues were examined to gauge the adverse effects of the treatment method's toxicity. The results showed that Cur-NE is more effective than free curcumin at slowing the growth of Ehrlich tumors while significantly increasing the levels of apoptotic proteins. On the other hand, Cur-NE-treated mice showed some damage in other organs when compared to mice treated with free curcumin. Cur-NE has a higher efficacy in treating Ehrlich tumor.

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.

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.

Molecular modeling study of micro and nanocurcumin with in vitro and in vivo antibacterial validation

Repurposing natural compounds as inhibitory targets to combat bacterial virulence is an important potential strategy to overcome resistance to traditional antibiotics, in the present study, the antibacterial activity of micro-curcumin and nano-sized curcumin was investigated against four predominant bacterial pathogens, namely, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis. Curcumin bactericidal susceptibility could be summarized as the order, P. aeruginosa > B. subtilis > S. aureus > E. coli. Molecular docking analysis was conducted to confirm the impact of curcumin on the most vital and positively identified quorum-sensing pathway signaling proteins SecA-SecY, LsrR, PqsR (MvfR), AgrA which act as key players in the bacterial communication systems. The in silico physicochemical properties revealed that curcumin as a nutraceutical can be classified as a drug-like compound. An in vivo infected wound model was employed in four groups of albino rats. Topical application of nano-curcumin lotion showed a marked reduction in wound area (98.8%) as well as nearly 100% reduction in total bacterial viable count compared to the control group, on the fifteenth day post-treatment post-injury. The obtained data suggested that curcumin nanoparticles exhibited superior antibacterial activity and may possess clinical utility as a novel topical antimicrobial and wound healing agent.

Comprehensive Metabolite Profile Uncovers the Bioactive Components, Antioxidant and Antibacterial Activities in Wild Tree Peony Leaves

Tree peonies (Paeonia Section Moutan)-including nine wild species, which belong to subsections Vaginatae and Delavayanae-are economically important plants with ornamental, nutritional, and medicinal applications. In this study, for the first time, we determined the bioactive components and antioxidant activities and antibacterial activities of the newly grown leaves of nine wild tree peony species (WTPS). A total of 276 bioactive components were identified through non-targeted metabolomics; more than 80% of the 276 metabolites identified are terpenoids and flavonoids. A total of 42 differential metabolites were quantitatively determined. The main differential metabolites were Paeoniflorin, Luteoloside, Hyperin, Apigenin-7-glucoside, Rhoifolin, and Cantharidin. Such a high terpenoid and flavonoid content of the leaf extracts renders them as species with strong antibacterial capacities, and most of the bacteria tested showed greater sensitivity derived from the members of subsection Vaginatae than those of subsection Delavayanae. All WTPS have significant antioxidant activity; this activity is attributed to high levels of the total phenolic content (TPC) and total flavonoid content (TFC), of which, among the nine WTPS, P. lutea has the strongest antioxidant capacity. Our results provided a theoretical basis for the in-deep application of tree peony leaves for food, medical, and pharmaceutical industries.

Antibacterial effect of kitchen herbs against pathogenic multidrug-resistant E. coli isolates from calf diarrhoea

Calf diarrhoea remains the biggest challenge both in the small and large farms. Infectious diarrhoea is associated with many pathogens, Escherichia coli being one, but majority are systematically treated with antibiotics. Since antimicrobial resistance (AMR) is a growing menace, the need to find alternative prophylactic solutions using popular kitchen herbs such as Trachyspermum ammi (carom seeds), Curcuma longa (turmeric) and cinnamon (Cinnamomum sp.) extracts is been investigated against virulent form of E. coli isolated from calf diarrhoea. The virulence factors identified in these isolates were ST (32.5%), LT (20%), eaeA (15%), stx1 (2.5%) and stx2 (5%) with the occurrence of the most common serogroups as O18 (15%) followed by O111 (12.5%). Highest resistance was seen with beta lactam + beta lactamase inhibitor (amoxicillin/clavulanic acid) followed by beta lactams (ampicillin, cefuroxime and cefepime). The zone of inhibition due to cinnamon (methanol) and carom seed (ethanol) extracts (500 to 250 μg/mL concentration) on E. coli bacteria was >19 mm, respectively. Turmeric, cinnamon and carom had the potency of inhibiting the pathogenic E. coli which maybe suggestive of its use in calf diets as prophylaxis against diarrhoea.

Effects of Curcumin on Growth Performance, Ruminal Fermentation, Rumen Microbial Protein Synthesis, and Serum Antioxidant Capacity in Housed Growing Lambs

This experiment was conducted to investigate growth performance, ruminal fermentation, rumen microbial protein synthesis, and serum antioxidant capacity with different doses of curcumin (CUR) included in the diet of housed growing lambs. Forty-eight four-month-old Dorper × Thin-tailed Han F₁ crossbred male lambs (body weight = 20.89 ± 1.15 kg, age = 120 ± 10 days; mean ± SD) were randomly divided into four groups for a single-factor, completely randomized experiment. Treatments comprised the following: the basal diet supplemented with 0 (Control), 300 mg/kg (300 CUR), 600 mg/kg (600 CUR), or 900 mg/kg (900 CUR) CUR, respectively. The results showed that dietary CUR increased average daily gain (ADG), and the 300 CUR group evidenced the highest value. There were no significant effects on dry matter intake (DMI) and DMI/ADG. Lambs in the 300 CUR group showed higher totals of volatile fatty acids (VFA) and acetate than other groups, while decreased valerate was observed with supplementary CUR. The ruminal pH and ammonia N (NH₃-N) concentration decreased with increasing CUR, with the greatest effect in the 300 CUR group. The quadratic effects were found in pectinase, carboxymethyl cellulose, and protease, with the greatest value in the 300 CUR group. The microbial populations of total bacteria and Ruminococcus albus also responded quadratically, and the methanogens, protozoan, and Fibrobacter succinogenes populations decreased linearly with increasing CUR. Lambs receiving additional CUR showed increased Prevotella ruminicola population. Microbial protein (MCP) synthesis was promoted by supplementary CUR. As supplementation with CUR increased, the serum activity of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) was enhanced, with the greatest value in the 300 CUR group. In conclusion, dietary CUR improved ruminal fermentation, promoted rumen microbial protein (MCP) synthesis, and enhanced serum antioxidant activity, as well as promoting growth performance in housed growing lambs.

Physico-Chemical Study of Curcumin and Its Application in O/W/O Multiple Emulsion

Curcuma is a world-renowned herb known for its immense health benefits. In this study, physicochemical analyses were performed on the curcumin standard sample and curcumin multiple emulsions. The emulsions were analysed for thermal and structural stability for 21 days. Confocal laser microscopy (CLSM) was performed in order to observe the emulsion encapsulation. Modulated differential scanning calorimetry (MDSC) and HPLC methods revealed a variety of curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin, and cyclocurcumin) in the investigated curcumin standard. In addition, the MDSC method was found to be suitable and comparable to HPLC for determining the curcuminoid substances. The analysis of the curcumin release revealed a value of 0.18 w.% after 14 days as the equilibrium value. Furthermore, an increase in the sizes of the emulsions was observed at the end of the 21-day study. The emulsion stability index (ESI) was used to measure the stability of multiple emulsions. The ESI reached 55.8% between 7 and 21 days later. Nano droplets of the oil phase loaded with dispersed curcumin particles captured inside the water-based carboxymethylcellulose micelles were clearly observed by CLSM.

Construction of nano slow-release systems for antibacterial active substances and its applications: A comprehensive review

At present, nano-carrier materials with antibacterial activity are of great significance. Due to the widespread resistance of many pathogenic microorganisms, it has seriously threatened human health. The natural antimicrobial substances extracted from fruits and vegetables can significantly improve their stability combined with nano-carrier materials. The resistance of pathogenic microorganisms will be substantially reduced, greatly enhancing the effect of active antimicrobial substances. Nanotechnology has excellent research prospects in the food industry, antibacterial preservation, food additives, food packaging, and other fields. This paper introduces nano-carrier materials and preparation techniques for loading and encapsulating active antibacterial substances in detail by constructing a nano-release system for active antibacterial substances. The antibacterial effect can be achieved by protecting them from adverse external conditions and destroying the membrane of pathogenic microorganisms. The mechanism of the slow release of the bacteriostatic active substance is also described. The mechanism of carrier loading and release is mainly through non-covalent forces between the bacteriostatic active substance and the carrier material, such as hydrogen bonding, π-π stacking, van der Waals forces, electrostatic interactions, etc., as well as the loading and adsorption of the bacteriostatic active substance by the chemical assembly. Finally, its wide application in food and medicine is introduced. It is hoped to provide a theoretical basis and technical support for the efficient utilization and product development of bacteriostatic active substances.

Probiotic Properties Including the Antioxidant and Hypoglycemic Ability of Lactic Acid Bacteria from Fermented Grains of Chinese Baijiu

In this study, lactic acid bacteria (LAB) strains were isolated from fermented grains of traditional Chinese Baijiu, and their probiotic properties were characterized. Eleven out of 29 LAB strains showed good tolerance to the gastrointestinal tract and bile salts. The surface characteristics (auto-aggregation, co-aggregation, hydrophobicity), safety (hemolytic and antibiotic sensitivity), antibacterial activity against three foodborne pathogens, and antioxidant and hypoglycemic properties of the 11 LAB strains were investigated. Principal component analysis (PCA) was used to comprehensively evaluate LAB strains and their probiotic properties. It was found that Weissella cibaria (OP288150), Pediococcus acidilactici (OP288151), Pediococcus pentosaceus (OP288154), Pediococcus pentosaceus (OP288156) and Levilactobacillus brevis (OP288158) showed high probiotic properties, with potential for commercial development. The results also demonstrated that fermented grains of Chinese Baijiu can be used as a source of high-quality probiotics.

Demonstration of the efficacy of curcumin on carbapenem-resistant Pseudomonas aeruginosa with Galleria mellonella larvae model

Due to increasing antimicrobial resistance, studies where new treatment options are investigated along with the synergistic effects of natural products with antibiotics have arisen. Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen and infection with multi-drug resistant (MDR) P. aeruginosa poses a critical problem during treatment. Curcumin (CUR) is listed in the literature as one of the promising natural ingredients with its strong antimicrobial activity. In our study, our aim was to investigate the in vitro synergistic effect of CUR with imipenem (IMP) and Colistin (CST) in MDR P. aeruginosa isolates and in vivo activity on Galleria mellonella (G. mellonella) larvae. Three clinical isolates of MDR P. aeruginosa, which were determined to be phenotypically resistant to carbapenems, were used, and KPC and OXA48 resistance genes were determined by PCR method. The synergistic effect of CUR with antibiotics were investigated by the checkerboard method. Larval survival and bacterial load were compared with the in vivo study. In this study, IMP MIC values were significantly reduced (two to eight-fold decrease) in the presence of CUR, and partial synergy was observed. For CST, this value decreased two-fold. Bacterial load was evaluated to investigate the effect of antimicrobials during infection. While the CFUs increased over time in non-treated larvae as compared to the initial inoculum, bacterial load was significantly decreased for the groups treated with CUR, IMP and CST compared to the untreated group (p < 0.05). It was concluded CUR-antibiotic combinations can provide an alternative approach in the treatment of infections with MDR bacteria.

Reconnoitering the Therapeutic Role of Curcumin in Disease Prevention and Treatment: Lessons Learnt and Future Directions

Turmeric is a plant with a very long history of medicinal use across different cultures. Curcumin is the active part of turmeric, which has exhibited various beneficial physiological and pharmacological effects. This review aims to critically appraise the corpus of literature associated with the above pharmacological properties of curcumin, with a specific focus on antioxidant, anti-inflammatory, anticancer and antimicrobial properties. We have also reviewed the different extraction strategies currently in practice, highlighting the strengths and drawbacks of each technique. Further, our review also summarizes the clinical trials that have been conducted with curcumin, which will allow the reader to get a quick insight into the disease/patient population of interest with the outcome that was investigated. Lastly, we have also highlighted the research areas that need to be further scrutinized to better grasp curcumin’s beneficial physiological and medicinal properties, which can then be translated to facilitate the design of better bioactive therapeutic leads.

Microencapsulation of curcumin by spray drying: Characterization and fortification of milk

Curcumin, the major bioactive component of turmeric (Curcuma longa), was microencapsulated by spray drying in the matrix of HI-CAP 100 (resistant starch)/ maltodextrin and whey protein isolate to improve its oral bioavailability and solubility. Taguchi orthogonal array design (L₁₈) was used to optimize the spray drying conditions. The optimal conditions for microencapsulation were inlet drying air temperature of 185 °C, feed rate of 6 mL/min and HI-CAP 100 as wall material. The moisture content, encapsulation efficiency and bulk density at these conditions were 4.65%, 82.42% and 358.40 kg/m³, respectively. The spray-dried microcapsules were spherical-shaped with folds and vacuoles. The yellowness index and a^* value of curcumin decreased after microencapsulation. FTIR spectroscopy indicated that the curcumin after microencapsulation presumably retained its chemical structure. DSC thermograms confirmed that the microcapsules were heat stable up to 200 °C. The microcapsules had better heat stability and sustained in-vitro release as compared to that of pure curcumin. The DPPH free radical scavenging activity of curcumin was 61.43%, which was largely unaffected after microencapsulation. Fortification of milk with HI-CAP 100-based microcapsules at the selected dose had no adverse effect on organoleptic properties as compared to normal milk.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05142-0.

Natural Food Colorants and Preservatives: A Review, a Demand, and a Challenge

The looming urgency of feeding the growing world population along with the increasing consumers' awareness and expectations have driven the evolution of food production systems and the processes and products applied in the food industry. Although substantial progress has been made on food additives, the controversy in which some of them are still shrouded has encouraged research on safer and healthier next generations. These additives can come from natural sources and confer numerous benefits for health, beyond serving the purpose of coloring or preserving, among others. As limiting factors, these additives are often related to stability, sustainability, and cost-effectiveness issues, which justify the need for innovative solutions. In this context, and with the advances witnessed in computers and computational methodologies for in silico experimental aid, the development of new safer and more efficient natural additives with dual functionality (colorant and preservative), for instance by the copigmentation phenomena, may be achieved more efficiently, circumventing the current difficulties.

The Natural Product Curcumin as an Antibacterial Agent: Current Achievements and Problems

The rapid spread of antibiotic resistance and lack of effective drugs for treating infections caused by multi-drug resistant bacteria in animal and human medicine have forced us to find new antibacterial strategies. Natural products have served as powerful therapeutics against bacterial infection and are still an important source for the discovery of novel antibacterial drugs. Curcumin, an important constituent of turmeric, is considered safe for oral consumption to treat bacterial infections. Many studies showed that curcumin exhibited antibacterial activities against Gram-negative and Gram-positive bacteria. The antibacterial action of curcumin involves the disruption of the bacterial membrane, inhibition of the production of bacterial virulence factors and biofilm formation, and the induction of oxidative stress. These characteristics also contribute to explain how curcumin acts a broad-spectrum antibacterial adjuvant, which was evidenced by the markedly additive or synergistical effects with various types of conventional antibiotics or non-antibiotic compounds. In this review, we summarize the antibacterial properties, underlying molecular mechanism of curcumin, and discuss its combination use, nano-formulations, safety, and current challenges towards development as an antibacterial agent. We hope that this review provides valuable insight, stimulates broader discussions, and spurs further developments around this promising natural product.

Preparation of Curcumin Hydrogel Beads for the Development of Functional Kulfi: A Tailoring Delivery System

Curcumin has been demonstrated to have biological activities and its fortification in food products is an important strategy to deliver bioactive ingredients at target sites. However, studies have documented a curcumin low bioavailability and low intake. Hence, combining functional ingredients with food should be needed to prevent widespread nutrient intake shortfalls and associated deficiencies. Thus, curcumin was encapsulated in calcium-alginate and their characteristics as well as in vitro release behavior of curcumin hydrogel beads (CHBs) was studied. Moreover, CHBs were fortified in development of functional Kulfi and their quality characteristics were studied. The encapsulation efficiency was up to 95.04%, indicating that most of the curcumin was entrapped. FTIR shifts in the bands were due to the replacement of sodium ions to the calcium ions. In vitro release (%) for CHBs was found to be 67.15% after 2 h, which increased slightly up to 67.88% after 4 h. The average swelling index of CHBs was found to be 10.21 to 37.92 from 2 to 12 h in PBS (pH 7.40). Control and Kulfi fortified with CHBs showed no significant difference (p > 0.05) in colour (L = 73.03 and 75.88) and the melting rate (0.88 mL/min and 0.63 mL/min), respectively. Standard plate count was reduced in the Kulfi fortified with CHBs (13.77 × 10⁴ CFU/mL) with high sensory score for overall acceptability (8.56) compared to the control (154.70 × 10⁴ CFU/mL). These findings suggested the feasibility of developing CHBs to mask the bitterness, enhance the solubility, and increase the bioavailability in gastrointestinal conditions. Additionally, Kulfi could be a suitable dairy delivery system for curcumin bioactive compounds.

Curcumin, the active substance of turmeric: its effects on health and ways to improve its bioavailability

Turmeric (Curcuma longa L.) is a spice utilized widely in India, China, and Southeast Asia as an aromatic stimulant, a food preservative, and coloring material. The commonly used names of turmeric are castor saffron, turmeric, and saffron root. Turmeric is a yellow-orange polyphenolic natural substance derived from C. longa rhizomes. It has been used to treat common inflammatory diseases, tumors, biliary diseases, anorexia, cough, topical wounds, diabetic injuries, liver disorders, rheumatism, and sinusitis. Extensive studies on the biological properties and pharmacological consequences of turmeric extracts have been conducted in recent years. Curcumin, the primary yellow biocomponent of turmeric, has anti-inflammatory, antioxidant, anticarcinogenic, antidiabetic, antibacterial, antiprotozoal, antiviral, antifibrotic, immunomodulatory, and antifungal properties. Defense assessment tests showed that curcumin is tolerated well at high doses, without adverse effects. Thus, curcumin is a highly active biological material with the potential to treat different diseases in modern medicine. This review article focuses on curcumin's biological characteristics. The most popular methods for curcumin encapsulation are also discussed. Several effective techniques and approaches have been proposed for curcuminoid capsulation, including nanocomplexing, gelation, complex coacervation, electrospraying, and solvent-free pH-driven encapsulation. This review also highlights curcumin's chemical properties, allowing the readers to expand their perspectives on its use in the development of functional products with health-promoting properties. © 2021 Society of Chemical Industry.

Effects of Curcumin on Aging: Molecular Mechanisms and Experimental Evidence

Aging is characterized by a progressive inability to maintain homeostasis, self-repair, renewal, performance, and fitness of different tissues throughout the lifespan. Senescence is occurring following enormous intracellular or extracellular stress stimuli. Cellular senescence serves as an antiproliferative process that causes permanent cell cycle arrest and restricts the lifespan. Senescent cells are characterized by terminal cell cycle arrest, enlarged lysosome, and DNA double-strand breaks as well as lipofuscin granularity, senescence-associated heterochromatin foci, and activation of DNA damage response. Curcumin, a hydrophobic polyphenol, is a bioactive chemical constituent of the rhizomes of Curcuma longa Linn (turmeric), which has been extensively used for the alleviation of various human disorders. In addition to its pleiotropic effects, curcumin has been suggested to have antiaging features. In this review, we summarized the therapeutic potential of curcumin in the prevention and delaying of the aging process.

Effects of organic acids on the chemotaxis profiles and biocontrol traits of antagonistic bacterial endophytes against root-rot disease in Panax notoginseng

Understanding the role of chemotaxis in ecological interactions between plants and microbes in the rhizosphere is necessary to optimize biocontrol strategies targeting plant soil-borne diseases. Therefore, we examined and profiled the antagonistic endophytic bacteria (AEB) population with chemotaxis potential in the medicinal plant Panax notoginseng using a cheA gene-based approach coupled with 16S rRNA sequencing. Phylogenetic analysis of the chemotactic AEB (CAEB) community in P. notoginseng enabled the identification of 56 CAEB strains affiliated with 30 species of Actinobacteria, Firmicutes, and Proteobacteria; Firmicutes, especially Bacillus, were predominant. We then systematically quantified the chemotactic response profiles of CAEB toward five organic acid (OA) attractants: citric acid, fumaric acid (FA), malic acid, oxalic acid, and succinic acid. Further hierarchical cluster analysis revealed that the chemotaxis of CAEB to the same attractant exhibited different patterns among not only genera but also species and even strains of the same species. Following chemotaxis and hierarchical analysis, we selected the strongest chemoattractant, fumaric acid (FA), as the target for evaluating the effects of OAs on the representative CAEB strain Bacillus amyloliquefaciens subsp. plantarum YP1. Application of FA significantly stimulated the chemotaxis ability and growth of YP1, and increased the transcript levels of cheA and biocontrol-related genes in YP1. This is the first study to characterise the diversity of chemotaxis profiles toward OAs in natural bacterial assemblages of P. notoginseng and to highlight how FA promotes the biocontrol-related traits of P. notoginseng-associated CAEB.

Microencapsulation of Photochromic Solution with Polyurea by Interfacial Polymerization

Photochromic materials are interesting materials because of their color-changing property under UV light and visible light irradiation. However, they are vulnerable to many factors, such as pH oxygen, ion, solvent, etc. because of the unsaturated bonds existing on the photochromic molecular. Microencapsulation of the photochromic materials can separate them from the surroundings. Here, photochromic microcapsules using 3,3-Diphenyl-3H-naphtho[2,1-b] pyran (NP)/solution as core and polyurea as shell via interfacial polymerization were prepared, and bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate (HALS 770) was used as photostabilizer. Fourier transform infrared spectroscopy (FTIR), a laser particle size analyzer, a scanning electron microscope (SEM), a thermogravimetric analyzer and an ultraviolet-visible spectrophotometer were used for characterization. The results showed that the microcapsules had a uniform particle size of about 0.56 μm when the percentage of the oil phase (core) in the emulsion was less than 15%, the addition amount of the emulsifier was 0.4%, and the stirring rate was 1800 r/min. The microcapsules showed better performance in thermal stability when the core/shell ratio was 1:1. The photostabilizer had little impact on the color-changing property of the microcapsule, but it could protect the microcapsules from UV light radiation aging.

Solid-State Fluorescent Selenium Quantum Dots by a Solvothermal-Assisted Sol-Gel Route for Curcumin Sensing

Toward the need for solid-state fluorescent quantum dots, resistant to self-quenching, we describe a solvothermal-assisted sol-gel method to synthesize Se quantum dots. Morphological and crystalline characterizations reveal that Se quantum dots (average size 3-8 nm) have a trigonal crystal structure. The presence of planar defects (dislocations, stacking faults, twins, and grain boundaries) suggests formation of Se nanocrystallites through aggregation-based crystal growth mechanisms. Under ultraviolet excitation, the quantum dots exhibit an excitation wavelength-dependent solid-state blue emission with an average lifetime of 1.96 ns. Depending on fluorescence quenching by curcumin, selenium quantum dots act as ideal candidates for inner filter effect-based curcumin sensing.

Suppressive effects of Streptococcus thermophilus KLDS 3.1003 on some foodborne pathogens revealed through in vitro, in vivo and genomic insights

Foodborne diseases (FBDs) remain a persistent global challenge and recent research efforts suggest that lactic acid bacteria (LAB) strains can contribute towards their prevention and treatment. This study investigates the genetic properties of Streptococcus thermophilus KLDS 3.1003 as a potential probiotic and health-promoting LAB strain as well as its in vitro and in vivo activities against two foodborne pathogens. In vitro, its antimicrobial activities and tolerance levels in simulated bile salts and acids were determined. The cytotoxic effects of the LAB strain in RAW264.7 cells were also evaluated. For in vivo evaluation, 24 BALB/c mice were orally administered control and trial diets for 14 days. Genomic analyses of this strain's bacteriocin configuration, stress response system and multidrug resistance genes were annotated to validate in vitro and in vivo results. In vitro antimicrobial results show that the cells and CFS of S. thermophilus KLDS 3.1003 could inhibit both pathogens with the former being more effective (P < 0.05). In addition, its cell-free supernatant (CFS) could inhibit the growth of both pathogens, with catalase treatment having the highest effect against it. More so, after 3 h of incubation, survivability levels of S. thermophilus KLDS 3.1003 were significantly high (P < 0.05). LPS-induced RAW264.7 cell activities were also significantly reduced by 108-109 CFU mL-1 of S. thermophilus KLDS. In vivo, significant weight losses were inhibited in the TSTEC group compared to the TSTSA group (P < 0.05). Moreover, pathogen-disrupted blood biochemical parameters like HDL, LDL, TP, TG, AST, ALT and some minerals were restored in the respective prevention groups (TSTEC and TSTSA). Genomic analyses showed that S. thermophilus KLDS 3.1003 has bacteriocin-coding peptides, which accounts for its antimicrobial abilities in vitro and in vivo. S. thermophilus KLDS 3.1003 is also endowed with intact genes for acid tolerance, salt-resistance, cold and heat shock responses and antioxidant activities, which are required to promote activities against the selected foodborne pathogens. This study showed that S. thermophilus KLDS 3.1003 has the genomic capacity to inhibit foodborne pathogens' growth in vitro and in vivo, thus qualifying it as a potential probiotic, antimicrobial and bio-therapeutic candidate.

Synergistic Antioxidant and Antibacterial Activity of Curcumin-C3 Encapsulated Chitosan Nanoparticles

BACKGROUND

Recent studies have focused on the nanoformulations of curcumin to enhance its solubility and bioavailability. The medicinal properties of curcumin-C3 complex, which is a combination of three curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) is less explored.

OBJECTIVE

The aim of this study was to prepare curcumin-C3 encapsulated in chitosan nanoparticles, characterize and evaluate their antioxidant and antibacterial potential.

METHODS

Ionic gelation method was used to prepare curcumin-C3 nanoparticles and was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and nanoparticle tracking analysis. In vitro assays were performed to assess drug release, antioxidant and antibacterial activities.

RESULTS

Curcumin-C3-chitosan nanoparticle showed an increased entrapment efficiency of >90%, drug release and improved antioxidant potential. Moreover, curcumin-C3-chitosan nanoparticle showed stronger inhibition of Escherichia coli and Staphylococcus aureus.

CONCLUSION

Chitosan is a suitable carrier for curcumin-C3 nanoparticle and can be used as a drug delivery system in the treatment of inflammatory and bacterial diseases.

Characterization and antimicrobial activity of microencapsulated citral with dextrin by spray drying

Aim of this work was to evaluate the antimicrobial activity and physical characteristics of citral microencapsulated with dextrin (Dx) by spray drying. The encapsulation was optimized using response surface methodology (RSM), maximizing yield and efficiency, considering as independent variables the citral:Dx ratio (1:5 and 1:20) and the inlet air temperature (120 and 200 °C). Yield and efficiency under optimal conditions were 71.9% and 99.9%, respectively. Antimicrobial activity against Escherichia coli, Salmonella enterica, Staphylococcus aureus and Bacillus cereus of the citral microparticles obtained under optimal conditions and of free citral was evaluated using the disk diffusion methodology. Both compounds showed a broad spectrum inhibitory effect, being Escherichia coli and Bacillus cereus the most sensitive microorganisms. The inhibition ratio varied between 55 and 75%, and the antibacterial activity was maintained after microencapsulation. The minimum inhibitory concentrations of free citral were above 0.8 mg/mL. The optimal citral microparticles showed acceptable physicochemical characteristics and broad-spectrum antimicrobial activity. Polymer and emulsifier used in microencapsulation protected the functional activity of citral, thus suggesting that these microparticles could be used in the design of antimicrobial food systems to extend the shelf life of perishable foods.

AP-64, Encoded by C5orf46, Exhibits Antimicrobial Activity against Gram-Negative Bacteria

Antimicrobial peptides (AMPs), which are evolutionarily conserved components of the innate immune response, contribute to the first line of defense against microbes in the skin and at mucosal surfaces. Here, we report the identification of a human peptide, encoded by the chromosome 5 open reading frame 46 (C5orf46) gene, as a type of AMP, which we termed antimicrobial peptide with 64 amino acid residues (AP-64). AP-64 is an anionic amphiphilic peptide lacking cysteines (MW = 7.2, PI = 4.54). AP-64 exhibited significant antibacterial activity against Gram-negative bacteria, including Escherichia coli DH5α, Escherichia coli O157:H7, Vibrio cholerae, and Pseudomonas aeruginosa. Moreover, AP-64 was efficient in combating Escherichia coli O157:H7 infections in a mouse model and exhibited cytotoxic effects against human T-cell lymphoma Jurkat and B-cell lymphoma Raji cells. We also observed that Gm94, encoded by mouse C5orf46 homologous gene, closely resembles AP-64 in its antibacterial properties. Compared with other human AMPs, AP-64 has distinct characteristics, including a longer sequence length, absence of cysteine residues, a highly anionic character, and cell toxicity. Together, this study identified that AP-64 is an AMP worthy of further investigation.

Can curcumin supplementation reduce plasma levels of gut-derived uremic toxins in hemodialysis patients? A pilot randomized, double-blind, controlled study

BACKGROUND

Gut dysbiosis is common in patients with chronic kidney disease (CKD) and is closely related to inflammatory processes. Some nutritional strategies, such as bioactive compounds present in curcumin, have been proposed as an option to modulate the gut microbiota and decrease the production of uremic toxins such as indoxyl sulfate (IS), p-cresyl sulfate (pCS) and indole-3 acetic acid (IAA).

OBJECTIVE

To evaluate the effects of curcumin supplementation on uremic toxins plasma levels produced by gut microbiota in patients with CKD on hemodialysis (HD).

METHODS

Randomized, double-blind trial in 28 patients [53.6 ± 13.4 years, fourteen men, BMI 26.7 ± 3.7 kg/m², dialysis vintage 37.5 (12-193) months]. Fourteen patients were randomly allocated to the curcumin group and received 100 mL of orange juice with 12 g carrot and 2.5 g of turmeric and 14 patients to the control group who received the same juice but without turmeric three times per week after HD sessions for three months. IS, pCS, IAA plasma levels were measured by reverse-phase high-performance liquid chromatography RESULTS: After three months of supplementation, the curcumin group showed a significant decrease in pCS plasma levels [from 32.4 (22.1-45.9) to 25.2 (17.9-37.9) mg/L, p = 0.009], which did not occur in the control group. No statistical difference was observed in IS and IAA levels in both groups.

CONCLUSION

The oral supplementation of curcumin for three months seems to reduce p-CS plasma levels in HD patients, suggesting a gut microbiota modulation.

Enhanced anti-cancer activity by localized delivery of curcumin form PVA/CNCs hydrogel membranes: Preparation and in vitro bioevaluation

This study targets to develop curcumin-loaded polyvinyl alcohol/cellulose nanocrystals (PVA/CNCs) membrane as localized delivery system for breast/liver cancer. A novel strategy was developed for enhancing encapsulation capacity and maximizing therapeutic efficiency of curcumin-loaded PVA/CNCs membranes. Membranes were prepared by solution-casting method using citric acid as crosslinker. SEM revealed that PVA/CNCs ratio (80:20) was chosen as the optimum for loading curcumin. FT-IR indicated that, curcumin was incorporated into PVA/CNCs in amorphous-phase via intermolecular hydrogen bond between curcumin and membrane components. Curcumin showed biphasic-release through burst-release of 41% of curcumin during the first hour, followed by sustained-release of 70% and 94% during 24 h and 48 h, respectively. In vitro cytotoxicity of PVA/CNCs/Curcumin membrane exhibited a selective inhibition proliferation of breast and liver cancer cells in a concentration-dependent without any toxic effect on normal cells. At high concentration (8 mg/ml) of PVA/CNCs/Curcumin, reduced viability to 35% and 7% of MCF-7 and Huh-7 cells, respectively; meanwhile high HFB-4 normal cell viability ≥80% was investigated. Antimicrobial activity of PVA/CNCs/Curcumin was investigated by multi-drug-resistant strains, and MIC values. PVA/CNCs/Curcumin membranes with concentration (40 mg/ml) showed broad-spectrum antimicrobial activities, thus inhibited ~96-99% of microbial growth. PVA/CNCs/Curcumin membranes could be as promised anti-infective biomaterials for breast and liver cancer wound healing.

Study on the optimal antagonistic effect of a bacterial complex against Monilinia fructicola in peach

Peach brown rot caused by Monilinia fructicola is one of the most economically destructive diseases of peach (Prunus persica L.) in some orchards of China. Biocontrol is a significant strategy that exhibits strong levels of control and ecologically sound concepts in disease management. The purpose of this study was to investigate the combined suppressive effects of three endophytic bacterial strains (xj-14, xj-15, and xj-16) and two soil rhizosphere bacterial strains (xj-A and xj-C) that were shown to have strong inhibitory activity toward M. fructicola in our previous study. The optimal strains and the optimized combination of strains were determined. The combination of strains xj-15 and xj-C inhibited M. fructicola more intensively for a longer period of time. Following the application of 1 × 109 CFU/mL bacterial complex to the fruits, leaves, and shoots of peach trees infected with M. fructicola, the rate of inhibition reached 73.80%, 83.33%, and 90.43%, respectively. A pot experiment using lettuce (Lactuca sativa) showed that inoculation with the bacterial complex significantly increased the growth of seedlings. In this study, some compound bacteria were more effective than those in previous study in suppressing disease and promoting growth, which have the potential to be further applied in the field.

Curcumin Nanocrystals: Production, Physicochemical Assessment, and In Vitro Evaluation of the Antimicrobial Effects against Bacterial Loading of the Implant Fixture

Background: This study aimed to prepare and study physicochemical properties as well as the antibacterial action of curcumin nanocrystals inside the implant fixture against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis). Methods: Curcumin nanocrystals were prepared via precipitation combined with the spray drying method. The produced curcumin nanocrystals were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Moreover, the in vitro antimicrobial effect of curcumin nanocrystals inside the implant fixture was assessed against E. coli, S. aureus, and E. faecalis. All implant-abutment assemblies were immersed in bacterial suspensions and were incubated at 24, 48, and 72 h. The contents of each implant were cultured to count the colony of bacteria at 37 °C for 24 h. Results: The prepared curcumin nanocrystals with a mean particle size of 95 nm and spherical morphology exhibited a removal rate of 99.99% for all bacteria. In addition, the colony-forming unit (CFU) of bacteria in exposure to nanocrystals significantly was reduced (p < 0.010) by increasing the time. Conclusions: Curcumin nanocrystals can be used inside the implant fixture as an antimicrobial agent in order to more stabilization of the implant.