In silico design and mechanistic study of niosome-encapsulated curcumin against multidrug-resistant Staphylococcus aureus biofilms

Medicinal plants: bioactive compounds, biological activities, combating multidrug-resistant microorganisms, and human health benefits - a comprehensive review

In recent years, medicinal plants have gained significant attention in modern medicine due to their accessibility, affordability, widespread acceptance, and safety, making herbal remedies highly valued globally. Consequently, ensuring medicinal plants' quality, efficacy, and safety has become a critical concern for developed and developing nations. The emergence of multidrug-resistant microorganisms poses a serious global health threat, particularly in low-income regions, despite significant advancements in antimicrobial drugs and medical research over the past century. The rapid spread of these multidrug-resistant infections is primarily attributed to improper prescriptions, overuse, and unregulated access to antibiotics. Addressing these challenges, the standardization of plant-derived pharmaceuticals could pave the way for a transformative era in healthcare. Preserving and leveraging the historical knowledge of medicinal plants is essential before such valuable information is lost. Recently, there has been growing interest among natural and pharmaceutical scientists in exploring medicinal plants as potential sources of antimicrobial agents. This current review aims to identify the most common pathogens threatening human health, analyze the factors contributing to the rise of drug-resistant microorganisms, and evaluate the widespread use of medicinal plants across various countries as alternative antibiotics, highlighting their unique mechanisms of antimicrobial resistance.

In Silico Analysis of Curcumin's Targeted Cancer Therapy: Folate Receptor Pathways and Molecular Interaction Insights

This study explores the therapeutic potential of curcumin (CUR) in cancer therapy, specifically examining its targeted transport through folate receptors and its interaction with certain proteins in breast cancer cell lines. We employed molecular docking technique to assess the binding affinities of CUR with proteins 1H1Q, 1UOM, 4JDD, 5U2D and MCF10A normal breast epithelial cell line protein 5UGB. Out of these, the CUR-1H1Q complex exhibited the greatest binding affinity. To assess the stability of this complex in a biological setting, we conducted molecular dynamics simulations of the 1H1Q-CUR complex for a duration of 100 ns. The simulations demonstrated an extremely stable Cα-backbone, exhibiting a consistently low root mean square deviation. The radius of gyration measurements suggested a condensed structure with specific areas of flexibility. The simulation revealed a consistent hydrogen bond between CUR and 1H1Q, indicating a robust and long-lasting interaction between the two molecules. The results indicate that the cytotoxicity of curcumin on MCF7 cancer cell lines is mainly affected by its interactions with several proteins found in these cancer cells. Among the four proteins tested, 1H1Q has the greatest influence. The high affinity of these proteins for curcumin, which results in the creation of stable complexes, seems to trigger cell death. Curcumin's biocompatibility and toxicological effects were investigated in both normal and cancerous cell lines. The study revealed enhanced biocompatibility and potential toxicity in cancerous cell lines, while demonstrating reduced toxicity in normal cell lines.

Pharmacological effects, formulations, and clinical research progress of curcumin

Curcumin, a polyphenolic compound derived from the traditional Chinese medicine turmeric, which has a variety of pharmacological effects, including anti-cancer, anti-inflammatory, antioxidant, and antiviral properties. However, its clinical application is hindered by low solubility and bioavailability. To overcome these limitations, researchers have developed various formulations such as nanoformulations, solid dispersions, and microspheres. These advancements have led to improved therapeutic effects and have facilitated the progression of clinical research, primarily focusing on Phase I and Phase II trials for conditions like diabetes, obesity, and metabolic syndrome. In recent years, there has been a noticeable increase in Phase III and IV clinical trials, particularly concerning oral and dental diseases and arthritis. This article reviews recent literature from both domestic and international sources, providing a comprehensive overview of curcumin's research progress, including its pharmacological mechanisms, formulation developments, and clinical studies.

Preparation, characterization, and in vivo activity of Gossypium hirsutum niosomes against cutaneous leishmaniasis caused by Leishmania major in a murine model: Parasite burden, gene expression, and histopathological profiling

The use of conventional drugs is not a satisfactory treatment for the disease. Therefore, there is a crucial need for alternative therapeutic approaches. This study aimed to investigate the potential anti-leishmanial activity of Gossypium hirsutum niosomes against cutaneous leishmaniasis in a murine model and evaluate their effectiveness by assessing parasite burden, immunomodulatory gene expression, and histopathological profile. We prepared G. hirsutum niosomes and characterized their morphology, size, Fourier transform infrared spectroscopy (FT-IR), and encapsulation efficiency. The in vivo anti-leishmanial activity of the niosomes was evaluated by assessing parasite burden, histopathological profile, and gene expression level. The spleen parasite load in BALB/c mice treated with different groups of G. hirsutum niosomes and G. hirsutum extracts (30%), demonstrated a significant decrease compared to Glucantime®. The least number of leishmanial parasites was observed in H and E-stained histological sections (grade+1), followed by G. hirsutum niosomes or G. hirsutum crude extract (grade+3), Glucantime® (grade+4) and the highest number in the untreated control group (grade+6). There was a substantial difference (P < 0.001) among various treatment groups. Moreover, G. hirsutum niosomes up-regulated the levels of the gene (particularly IFN-γ, P < 0.001) compared to the extract form and Glucantime®. In contrast, IL-4, IL-10, and TNF-β were significantly decreased (P < 0.001) in comparison to untreated control. These results suggest that G. hirsutum niosomes have the potential to be considered a promising alternative therapy for leishmaniasis. Further research is warranted to explore their mechanism of action and optimize their formulation for clinical use.

Natural compounds in the fight against Staphylococcus aureus biofilms: a review of antibiofilm strategies

Staphylococcus aureus is an important pathogen due to its ability to form strong biofilms and antibiotic resistance. Biofilms play an important role in bacterial survival against the host immune system and antibiotics. Natural compounds (NCs) have diverse bioactive properties with a low probability of resistance, making them promising candidates for biofilm control. NC such as curcumin, cinnamaldehyde, carvacrol, eugenol, thymol, citral, linalool, 1,8-cineole, pinene, cymene, terpineol, quercetin, and limonene have been widely utilized for the inhibition and destruction of S. aureus biofilms. NCs influence biofilm formation through several procedures. Some of the antibiofilm mechanisms of NCs are direct bactericidal effect, disrupting the quorum sensing system, preventing bacteria from aggregation and attachment to surfaces, reducing the microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), interfering with sortase A enzyme, and altering the expression of biofilm-associated genes such as icaADBC, agr, and sarA. Furthermore, these compounds affect extracellular polymeric substances (EPS) and their components, such as polysaccharide intercellular adhesin (PIA) and eDNA. However, some disadvantages, such as low water solubility and bioavailability, limit their clinical usage. Therefore, scientists have considered using nanotechnology and drug platforms to improve NC's efficacy. Some NC, such as thymol and curcumin, can also enhance photodynamic therapy against S. aurous biofilm community. This article evaluates the anti-biofilm potential of NC, their mechanisms of action against S. aureus biofilms, and various aspects of their application.

Recent Progress in Terrestrial Biota Derived Antibacterial Agents for Medical Applications

Conventional antibiotic and multidrug treatments are becoming less and less effective and the discovery of new effective and safe antibacterial agents is becoming a global priority. Returning to a natural antibacterial product is a relatively new current trend. Terrestrial biota is a rich source of biologically active substances whose antibacterial potential has not been fully utilized. The aim of this review is to present the current state-of-the-art terrestrial biota-derived antibacterial agents inspired by natural treatments. It summarizes the most important sources and newly identified or modified antibacterial agents and treatments from the last five years. It focuses on the significance of plant- animal- and bacteria-derived biologically active agents as powerful alternatives to antibiotics, as well as the advantages of utilizing natural antibacterial molecules alone or in combination with antibiotics. The main conclusion is that terrestrial biota-derived antibacterial products and substances open a variety of new ways for modern improved therapeutic strategies. New terrestrial sources of known antibacterial agents and new antibacterial agents from terrestrial biota were discovered during the last 5 years, which are under investigation together with some long-ago known but now experiencing their renaissance for the development of new medical treatments. The use of natural antibacterial peptides as well as combinational therapy by commercial antibiotics and natural products is outlined as the most promising method for treating bacterial infections. In vivo testing and clinical trials are necessary to reach clinical application.

Chitosan‐based pH‐sensitive antibacterial bionanocomposites with laponite immobilized silver nanoparticles for delivery of sunitinib maleate to breast cancers

In this work, new pH‐sensitive and antibacterial drug carrier systems based on silver nanoparticles (AgNPs) embedded in the interlayer of laponite (Lap) in the presence of chitosan (CTS) for the controllable release of sunitinib maleate (STM) were developed. Silver ions and sunitinib maleate were first loaded into Lap, and the CTS‐based hybrid bionanocomposite carrier (Lap@CTS@AgNPs@STM) was obtained in the presence of citric acid as a cross‐linker agent. The successful preparation of nanocarrier and Ag NPs formation was thoroughly confirmed using techniques such as FTIR, XRD, TGA, SEM, and TEM. TEM images illustrated the excellent distribution of Ag NPs in the structure of Lap@CTS@AgNPs. The as‐prepared samples showed a pH‐sensitive anticancer drug release behavior. The STM release mechanism was studied using Korsmeyer–Peppas and Higuchi kinetic models. Furthermore, the in vitro cytotoxicity and antibacterial tests were carried out against both bacteria S. aureus and E. coli and MCF‐7 cell lines, respectively, to prove the effectiveness of synthesized samples as multifunctional carrier systems for biomedical applications.

Preparation and optimization of niosome encapsulated meropenem for significant antibacterial and anti-biofilm activity against methicillin-resistant Staphylococcus aureus isolates

Background

One of the targeted drug delivery systems is the use of nanocarriers, and one of these drug delivery systems is niosome. Niosome have a nano-vesicular structure and are composed of non-ionic surfactants. Objective: In this study, various niosome-encapsulated meropenem formulations were prepared. Subsequently, their antibacterial and anti-biofilm activities were evaluated against methicillin-resistant Staphylococcus aureus (MRSA) strains.

Methods

The physicochemical properties of niosomal formulations were characterized using a field scanning electron microscope, X-Ray diffraction, Zeta potential, and dynamic light scattering. Antibacterial and anti-biofilm activities were evaluated using broth microdilution and minimum biofilm inhibitory concentration, respectively. In addition, biofilm gene expression analysis was performed using quantitative Real-Time PCR. To evaluate biocompatibility, the cytotoxicity of niosome-encapsulated meropenem in a normal human diploid fibroblast (HDF) cell line was investigated using an MTT assay.

Results

An F1 formulation of niosome-encapsulated meropenem with a size of 51.3 ± 5.84 nm and an encapsulation efficiency of 84.86 ± 3.14 % was achieved. The synthesized niosomes prevented biofilm capacity with a biofilm growth inhibition index of 69 % and significantly downregulated icaD, FnbA, Ebps, and Bap gene expression in MRSA strains (p < 0.05). In addition, the F1 formulation increased antibacterial activity by 4-6 times compared with free meropenem. Interestingly, the F1 formulation of niosome-encapsulated meropenem indicated cell viability >90 % at all tested concentrations against normal HDF cells. The results of the present study indicate that niosome-encapsulated meropenem increased antibacterial and anti-biofilm activities without profound cytotoxicity in normal human cells, which could prove useful as a good drug delivery system.

Identifying potential Alzheimer's disease therapeutics through GSK-3β inhibition: A molecular docking and dynamics approach

Emerging as a promising drug target for Alzheimer's disease (AD) therapy, glycogen synthase kinase 3β (GSK-3β) has garnered attention. This study sought to rigorously scrutinize a compendium of natural compounds retrieved from the ZINC database through pharmacodynamic experiments, employing a 1 H-indazole-3-carboxamide (INDZ) scaffold, to identify compounds capable of inhibiting the GSK-3β protein. Utilizing a multi-step approach, the study involved pharmacophore analysis, followed by molecular docking to select five promising ligands for further investigation. Subsequently, ESMACS simulations were employed to assess the stability of the ligand-protein interactions. Evaluation of the binding modes and free energy of the ligands revealed that five compounds (2a-6a) exhibited crucial interactions with the active site residues. Furthermore, various methodologies, including hydrogen bond and clustering analyses, were utilized to ascertain their inhibitory potential and elucidate the factors contributing to ligand binding in the protein's active site. The findings from MMPBSA/GBSA analysis indicated that these five selected small molecules closely approached the IC50 value of the reference ligand (OH8), yielding energy values of -34.85, -32.58, -31.71, and -30.39 kcal/mol, respectively. Additionally, an assessment of the interactions using hydrogen bond and dynamic analyses delineated the effective binding of the ligands with the binding pockets in the protein. Through computational analysis, we obtained valuable insights into the molecular mechanisms of GSK-3β, aiding in the development of more potent inhibitors.

Formulation, preparation of niosome loaded zinc oxide nanoparticles and biological activities

In this study, zinc oxide nanoparticles (Zn-NPs) were prepared by the green synthesis method and loaded inside niosomes as a drug release system and their physicochemical and biological properties were determined. Zn-NPs were prepared by the eco-friendly green strategy, the structure, and morphological properties were studied and loaded into niosomes. Subsequently, different formulations of niosomes containing Zn-NPs were prepared and the optimal formulation was used for biological studies. Scanning electron microscope (SEM) and dynamic light scattering (DLS) were used to investigate the morphology and size of nanoparticles. Fourier transform infrared spectroscopy (FTIR) and UV-Vis were used to confirm the synthesis of Zn-NPs. Energy dispersive X-ray spectrometer (EDS) determined the elemental analysis of the Zn-NPs synthesis solution and the crystalline structure of Zn-NPs was analysed by XRD (X-Ray diffraction). Furthermore, Zn-NPs were loaded inside the niosomes, and their structural characteristics, entrapment efficiency (EE%), the release profile of Zn-NPs, and their stability also were assessed. Moreover, its antimicrobial properties against some microbial pathogens, its effect on the expression of biofilm genes, and its anticancer activity on the breast cancer cell lines were also determined. To study the cytocompatibility, exposure of niosomes against normal HEK-293 cells was carried out. In addition, the impact of niosomes on the expression of genes involved in the apoptosis (Bcl2, Casp3, Casp9, Bax) at the mRNA level was measured. Our findings revealed that the Zn-NPs have a round shape and an average size of 27.60 nm. Meanwhile, UV-Vis, FTIR, and XRD results confirmed the synthesis of Zn-NPs. Also, the EE% and the size of the optimized niosomal formulation were 31.26% and 256.6 ± 12 nm, respectively. The release profile showed that within 24 h, 26% of Zn-NPs were released from niosomes, while in the same period, 99% of free Zn-NPs were released, which indicates the slow release of Zn-NPs from niosomes. Antimicrobial effects exhibited that niosomes containing Zn-NPs had more significant antimicrobial and anti-biofilm effects than Zn-NPs alone, the antimicrobial and anti-biofilm effects increased 2 to 4 times. Cytotoxic effects indicated that when Zn-NPs are loaded into niosomes, the anticancer activity increases compared to Zn-NPs alone and has low cytotoxicity on cancer cells. Niosomes containing ZnNPs increased the apoptosis-related gene expression level and reduced the Bcl2 genes. In general, the results show that niosomes can increase the biological effects of free Zn-NPs and therefore can be a suitable carrier for targeted delivery of Zn-NPs.

Biofilm Inhibition on Medical Devices and Implants Using Carbon Dots: An Updated Review

Biofilms are an intricate community of microbes that colonize solid surfaces, communicating via a quorum-sensing mechanism. These microbial aggregates secrete exopolysaccharides facilitating adhesion and conferring resistance to drugs and antimicrobial agents. The escalating global concern over biofilm-related infections on medical devices underscores the severe threat to human health. Carbon dots (CDs) have emerged as a promising substrate to combat microbes and disrupt biofilm matrices. Their numerous advantages such as facile surface functionalization and specific antimicrobial properties, position them as innovative anti-biofilm agents. Due to their minuscule size, CDs can penetrate microbial cells, inhibiting growth via cytoplasmic leakage, reactive oxygen species (ROS) generation, and genetic material fragmentation. Research has demonstrated the efficacy of CDs in inhibiting biofilms formed by key pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Consequently, the development of CD-based coatings and hydrogels holds promise for eradicating biofilm formation, thereby enhancing treatment efficacy, reducing clinical expenses, and minimizing the need for implant revision surgeries. This review provides insights into the mechanisms of biofilm formation on implants, surveys major biofilm-forming pathogens and associated infections, and specifically highlights the anti-biofilm properties of CDs emphasizing their potential as coatings on medical implants.

Development and characterization of a topical gel, containing lavender (Lavandula angustifolia) oil loaded solid lipid nanoparticles

Gels loaded with nanocarriers offer interesting ways to create novel therapeutic approaches by fusing the benefits of gel and nanotechnology. Clinical studies indicate that lavender oil (Lav-O) has a positive impact on accelerating wound healing properly based on its antimicrobial and anti-inflammatory effects. Initially Lav-O loaded Solid Lipid Nanoparticles (Lav-SLN) were prepared incorporating cholesterol and lecithin natural lipids and prepared SLNs were characterized. Next, a 3% SLN containing topical gel (Lav-SLN-G) was formulated using Carbopol 940. Both Lav-SLN and Lav-SLN-G were assessed in terms antibacterial effects against S. aureus. Lav-SLNs revealed a particle size of 19.24 nm, zeta potential of -21.6 mv and EE% of 75.46%. Formulated topical gel presented an acceptable pH and texture properties. Minimum Inhibitory/Bactericidal Concentration (MIC/MBC) against S. aureus for LAv-O, Lav-SLN and Lav-SLN-G were 0.12 and 0.24 mgml- 1, 0.05 and 0.19 mgml- 1 and 0.045, 0.09 mgml- 1, respectively. Therefore, SLN can be considered as an antimicrobial potentiating nano-carrier for delivery of Lav-O as an antimicrobial and anti-inflammatory agent in topical gel.

Antimicrobial and antibiofilm activity of highly soluble polypyrrole against methicillin-resistant Staphylococcus aureus

AIMS

The purpose was to evaluate the antimicrobial activity of highly soluble polypyrrole (Hs-PPy), alone or combined with oxacillin, as well as its antibiofilm potential against methicillin-resistant Staphylococcus aureus strains. Furthermore, the in silico inhibitory mechanism in efflux pumps was also investigated.

METHODS AND RESULTS

Ten clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and two reference strains were used. Antimicrobial activity was determined by broth microdilution, and the combination effect with oxacillin was evaluated by the checkerboard assay. The biofilm formation capacity of MRSA and the interference of Hs-PPy were evaluated. The inhibitory action of Hs-PPy on the efflux pump was evaluated in silico through molecular docking. Hs-PPy showed activity against the isolates, with inhibitory action between 62.5 and 125 µg ml-1 and bactericidal action at 62.5 µg ml-1, as well as synergism in association with oxacillin. The isolates ranged from moderate to strong biofilm producers, and Hs-PPy interfered with the formation of this structure, but not with mature biofilm. There was no in silico interaction with the efflux protein EmrD, the closest homolog to NorA.

CONCLUSIONS

Hs-PPy interferes with biofilm formation by MRSA, has synergistic potential, and is an efflux pump inhibitor.

Preparation of the Myricetin-Loaded PEGylated Niosomes and Evaluation of their in vitro Anti-Cancer Potentials

Several edible plants contain flavonoids, including myricetin (Myr), which perform a wide range of biological activities. Myr has antitumor properties against various tumor cells. In this study Myr-loaded PEGylated niosomes (Myr-PN) were prepared and their anti-cancer activities were evaluated in vitro. Myr-PNs were prepared as a tool for drug delivery to the tumor site. Myr-PN was characterized in terms of size, zeta potential, and functional groups using dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (SEM). The Myr-PN size was 241 nm with a polydispersity index (PDI) of 0.20, and zeta potential -32.7±6.6 mV. Apoptotic properties of Myr-PN against normal and cancer cell lines were determined by flow cytometry and real-time quantitative PCR. Cancer cells showed higher cytotoxicity when treated with Myr-PN compared with normal cells, indicating that the synthesized nanoparticles pose no adverse effects. Apoptosis was induced in cells treated with 250 μg/mL of Myr-PN, in which 45.2 % of cells were arrested in subG1, suggesting that Myr-PN can induce apoptosis. In vitro, the synthesized Myr-PN demonstrated potent anticancer properties. Furthermore, more research should be conducted in vitro and in vivo to study the more details of Myr-PN anti-cancer effects.

Enhanced antibacterial activity of porous chitosan-based hydrogels crosslinked with gelatin and metal ions

Addressing the increasing drug resistance in pathogenic microbes, a significant threat to public health, calls for the development of innovative antibacterial agents with versatile capabilities. To enhance the antimicrobial activity of non-toxic biomaterials in this regard, this study focuses on novel, cost-effective chitosan (CS)-based hydrogels, crosslinked using gelatin (GEL), formaldehyde, and metallic salts (Ag+, Cu2+, and Zn2+). These hydrogels are formed by mixing CS and GEL with formaldehyde, creating iminium ion crosslinks with metallic salts without hazardous crosslinkers. Characterization techniques like FTIR, XRD, FESEM, EDX, and rheological tests were employed. FTIR analysis showed metal ions binding to amino and hydroxyl groups on CS, enhancing hydrogelation. FESEM revealed that freeze-dried hydrogels possess a crosslinked, porous structure influenced by various metal ions. Antibacterial testing against gram-negative and gram-positive bacteria demonstrated significant bacterial growth inhibition. CS-based hydrogels containing metal ions showed reduced MIC and MBC values against Staphylococcus aureus (0.5, 8, 16 µg/mL) and Escherichia coli (1, 16, 8 µg/mL) for CS-g-GEL-Ag+, CS-g-GEL-Cu2+, and CS-g-GEL-Zn2+. MTT assay results confirmed high biocompatibility (84.27%, 85.24%, 84.96% viability at 10 µg/mL) for CS-based hydrogels towards HFF-1 cells over 48 h. Therefore, due to their non-toxic nature, these CS hydrogels are promising for antibacterial applications.

Regulation and mechanism of organic selenium on quorum sensing, biofilm, and antioxidant effects of Lactobacillus paracasei

Different organic compounds can have varying degrees of impact on the activity of Lactobacillus paracasei. The study focused on the impact and action mechanism of different organic selenium products on the bioactivity of two strains of L. paracasei. The growth, antioxidant activity, extracellular polysaccharide secretion, quorum sensing (QS), and biofilm formation of the strains before and after the addition of organic selenium crude products and three organic selenium standard were evaluated. The results showed that the addition of crude organic selenium promoted the various activities of the strain. l-selenocysteine had the strongest regulatory effect, with maximum GIM1.80 biofilm formation when it reached a critical concentration of 0.4 μg/mL; l-selenomethionine resulted in the highest activity of the signal molecule Auto inducer-2 of GDMCC1.155, when it reached a critical concentration of 0.4 μg/mL. The results of scanning electron microscopy demonstrated that the addition of organic selenium effectively improved the morphological structure of the two bacterial cells. Molecular docking revealed that the mechanism by which organic selenium regulates QS in Lactobacillus was achieved by binding two crucial receptor proteins (histidine protein kinase HKP and periplasmic binding protein LuxP) from specific sites. Furthermore, organic selenium products have a beneficial regulatory effect on the biological activity of L. paracasei. Overall, these findings provide a new alternative (organic selenium) for regulating the viability and beneficial activity of L. paracasei.