Antimicrobial Properties Research Articles

Extract from Psidium guineense Sw leaves: An alternative against resistant strains of Staphylococcus aureus

Psidium guineense SW., commonly known as sour guava, is used in traditional medicine to address diverse health issues, such as inflammation, infections, and gastrointestinal disorders. Although previous research has highlighted the antimicrobial properties of the root extract and the antioxidant potential of its fruits, information regarding the activities associated with the leaf extract is lacking. The aim of the study was to use the traditional knowledge of the biological properties of P. guineense and investigate its antimicrobial activity, mechanism of action, synergistic effects, and antivirulence activity against Staphylococcus aureus. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined for S. aureus, including antibiotic-resistant isolates. The synergy between the extract and antibiotics was evaluated. A growth curve was constructed for S. aureus treated with the extract. The anti-hemolytic activity was assessed by inhibiting hemolysis in human blood, and the inhibition of staphyloxanthin (STX) was examined. The extract effectively inhibited all strains with MIC and MBC values ranging from 256 to 512 µg/mL and 512 to 1024 µg/mL, respectively. Antimicrobial synergy experiments demonstrated the enhanced effectiveness of antibiotics, especially ciprofloxacin, when combined with the P. guineense extract, especially with ciprofloxacin, resulting in complete synergy against all S. aureus strains. In growth curve tests, the extract inhibited growth at MIC of 256 µg/mL within 8 h and significantly delayed it at MIC/2 (128 µg/mL) within 12 h. In antivirulence tests, the extract effectively reduced hemolysis and STX production by S. aureus at MIC and MIC/2, indicating its potential as an antimicrobial agent with antivirulence properties. The extract effectively inhibited S. aureus, including drug-resistant strains with low MIC and MBC values, exhibiting strong antimicrobial and synergistic properties with antibiotics. also In addition, the extract accelerated recovery by limiting bacterial growth and exhibiting antivirulence capabilities, reducing the severe symptoms of S. aureus infections.

The effect of the modified starch with side chain on the morphology of copper particles and the antibacterial properties of starch/copper composite material

In this paper, corn starch was modified by acetylation, esterification and amination, and the effects of different modifications on the structure and physicochemical properties of starch were investigated. And starch/copper composite materials were prepared by adding copper salts to the different modified starch, and the influence of modified starch and their additive amount on the morphology of copper and the antimicrobial properties were discussed. The results showed that: the contact angle of the modified starch was about 50° and exhibited hydrophilic-hydrophobic transition; the esterified starch had the smallest heat weight loss; the different modifications caused damage to the structure of the starch, which changed from the original smooth surface to a rough and wrinkled surface; hexahedral morphology copper particles were obtained by replacing them with the modified starch; the antimicrobial effect of the prepared starch/copper composite materials were related to the modification mode of starch, in which aminated starch show the best antimicrobial effect. This study provides a theoretical basis for the selection of starch type in the preparation of starch/copper composite materials in the future, which can also be used as antimicrobial components in other applications.

Fabrication and characterization of double-layer active intelligent film based on chitosan, polyvinyl alcohol, grape skin anthocyanin and selenium nanoparticle

This study involved the fabrication of double-layer intelligent films using chitosan (CS), polyvinyl alcohol (PVA), grape skin anthocyanin (GSA), gellan gum (GG) and selenium nanoparticles (SeNPs). The CS/PVA/GSA layer functioned as the internal indicator layer, and the GG/SeNPs layer acted as the external layer for antioxidant and antimicrobial purposes. SEM, FTIR, XRD, and TGA results confirmed the successful fabrication of double-layer films as well as the presence of hydrogen bonding interaction between the two layers. The tensile strength of double-layer films (8.06 MPa–9.61 MPa) fallen between that of single-layer CS/PVA/GSA film (12.51 MPa) and GG/SeNPs film (1.50 MPa–7.67 MPa). The double-layer films demonstrated good UV-blocking abilities, as well as outstanding antioxidant (ABTS scavenging rate can be up to ~80 %) and antimicrobial properties. Compared with single-layer CS/PVA/GSA film, the double-layer film incorporated with 6.6 wt% SeNPs (CPG/GS2 film) possessed a more rapid and stronger response towards NH3/acetic acid as well as enhanced storage stability. Furthermore, the CPG/GS2 film can increase the shelf life of strawberries at 25 °C by 4 days, and its visible color change showed strong correlation with the weight loss rate (R2 = 0.99) and hardness (R2 = 0.98) of strawberries.

Novel high-strength, recyclable, microbial-resistant, and freeze-thaw dual topological network hydrogel cooling media

The demand for multifunctional hydrogels, offering high mechanical strength, efficient cooling, and antimicrobial properties, is growing in food preservation. Here, a dual-network (DN) hydrogel PM@Cur, which includes curcumin, is fabricated through chemical crosslinking and hydrogen bonding interactions. The resulting hydrogels can withstand more than five freeze-thaw cycles at −80 °C, and resist brittleness after liquid nitrogen treatment. PM@Cur also exhibits surface hydrophobicity (contact angle >90°) for both water and organic solvents. These properties meet the mechanical, anti-fouling, and recyclable demands for hydrogel coolants. The antimicrobial assays in vitro confirmed that the inclusion of curcumin provided the PM@Cur with photodynamic antimicrobial capacity. Finally, the prepared PM@Cur hydrogel ice cubes have been confirmed to exhibit better anti-melting properties than traditional ice cubes, thus enabling the preservation of strawberries and shrimp. This study presents an innovative solution for producing advanced functional integrated hydrogels, offering a promising and safer option for food coolants.\\.

Lactoperoxidase Inhibition of Celecoxib Derivatives Containing the Pyrazole Linked‐Sulfonamide Moiety: Antioxidant Capacity, Antimicrobial Activity, and Molecular Docking Studies

ABSTRACTCelecoxib derivatives that contain the pyrazole‐linked sulfonamide moiety were synthesized, and the in vitro inhibitory impacts of the aforesaid compounds against the lactoperoxidase (LPO) enzyme were researched. To this end, LPO was purified using the affinity chromatography technique with a yield of 12.63% (319.23‐fold). The results showed that the aromatic pyrazole compound (compound 1) containing 2,3‐dimethoxyphenyl functional groups was the most effective LPO inhibitor with a Ki value of 3.2 ± 0.7 nM and noncompetitive inhibition type. The second section of the study tested the previously synthesized compounds to reveal their antioxidant and antimicrobial properties. The above‐mentioned compound also displayed high activity levels compared to standard antibiotics and antifungals, while all other compounds also showed antibacterial activity. In the three antioxidant methods we used, the compound with 2,5‐dimethoxy phenyl groups obtained from the reaction of the aromatic pyrazole compound with propionic anhydride in the presence of NEt3 displayed the highest activity. Furthermore, molecular docking and molecular mechanics studies were conducted to complement and validate the experimental findings. The results obtained from these computational analyses are highly consistent with the experimental data.

Bioactive ECM-Mimicking Nerve Guidance Conduit for Enhancing Peripheral Nerve Repair

Extensive research efforts are being directed towards identifying alternatives to autografts for the treatment of peripheral nerve injuries (PNIs) with engineered nerve conduits (NGCs) identified as having potential for PNI patients. These NGCs, however, may not fulfill the necessary criteria for a successful transplant, such as sufficient mechanical structural support and functionalization. To address the aforementioned limitations of NGCs, the present investigation explored the development of double cross-linked hydrogels (o-CSMA-E) that integrate the biocompatibility of porcine tendon extracellular matrix (ECM) with the antimicrobial and conductive properties of methacrylated quaternary chitosan. The hydrogels had matrices that could promote the growth of axons and the transmission of neural signals. The hydrogels were subsequently incorporated into a nanofibrous PLLA-ZnO sheath scaffold (ZnO@PLLA) to emulate the natural nerve structure, guiding cell growth and facilitating nerve regeneration. The collaboration of core and sheath materials in ZnO@PLLA/o-CSMA-E nerve guidance conduits resulted in enhanced migration of Schwann cells, formation of myelin sheaths, and improved locomotion performance in rats with sciatic nerve defects when in vivo studies were undertaken. Notably, the in vivo studies demonstrated the similarity between the newly developed engineered NGCs and autologous transplants, with the newly engineered NGCs possessing the potential to promote functional recovery by mimicking the tubular structure and ECM of nerves.

Comparative phytochemical profile and biological activity of three Terminalia species as alternative antimicrobial therapies

Ethnopharmacological relevanceMedicinal plants can help combat antibiotic resistance by providing novel, active molecules. Three plant species of the Terminalia genus are widely used in traditional medicine in the Mouhoun region for the treatment of cutaneous and respiratory diseases. Therefore, it is important to determine the ethnopharmacological potential of bark extracts from the trunks of these three Terminalia species. Aim of the studyThis study compared the phytochemical and biological activities of extracts from three Terminalia species to determine their ethnopharmacology. Materials and methodsThe medicinal properties of the extracts were assessed based on their ability to inhibit the growth of the following microorganisms: Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, Candida krusei, Candida glabrata, and Candida tropicalis. The significant interest in these medicinal plants among the local communities were elucidated by their antioxidant properties and phytochemical composition, along with the detection key bioactive compounds. Major phytochemical groups and phenolic compounds were determined using high-performance liquid chromatography with a diode array detector. These phytochemical findings were validated by evaluating the antioxidant capacity of the extracts using DPPH, FRAP, and ABTS assays. ResultsHydroethanolic, ethanolic, and hexane extracts from the bark of three Terminalia species inhibited the growth of both bacteria and fungi, as evidenced by their minimum inhibitory concentrations (MICs).The findings showed that Terminalia species were most effective against various tested bacteria and fungi, with MICs ranging from 0.1 to 6.25 mg/mL. Terminalia avicennioides, Terminalia macroptera, and Terminalia laxiflora extracts demonstrated 50 % inhibition of DPPH at concentrations ranging from 0.04 to 0.6 mg/mL. Phytochemical analysis revealed the presence of several families of chemical compounds, such as total phenolics and flavonoids. Phenolic compounds identified by HPLC in ethanolic extracts of T. avicennioides, such as isorhamnetin, quercetin, and ferulic acid, are recognised for their antimicrobial and antioxidant properties. ConclusionThese findings establish an ethnobotany for these three Terminalia species, with their chromatographic characteristics facilitating the identification of key molecules of interest. The ethanolic extract of T. avicennioides can be used in phytomedicinal formulations against bacterial (P. aeruginosa and S. aureus) and fungal (C. albicans and C. glabrata) infections, both of which are recurrently recorded in certain skin and respiratory tract diseases.

Research Update on the Therapeutic Potential of Garden Cress (Lepidium sativum Linn.) with Threatened Status.

Garden cress (Lepidium sativum) has been used in India for medicinal purposes since the Vedic era. Garden cress, a native of Egypt and southwest Asia, is a small perennial edible herb that has been used to treat many diseases for centuries. The seeds, leaves as well as roots have medicinal properties. The seeds are rich in protein, fat, calcium, and iron and have high nutritional value. They are considered to be galactagogue, anticarcinogenic, antidiabetic, antiasthmatic and antidiarrheal. Leaves, seeds, and aerial parts extracts are found to have alkaloids, flavonoids, glycosides, polypeptides, vitamins, minerals, proteins, fats, and carbohydrates. Lepidium sativum is known for its pungent odor due to the several volatile oils and has been used to treat various conditions, including respiratory disorders, muscle pain, inflammation, and bone fractures in the past. Lepidium sativum is a fast-growing annual herb; in India, it is commonly known as Chandrasoor. Whole fruits or seeds are used, fresh or dried, as a seasoning with a peppery flavor. Boiled seeds are consumed in drinks by Arabs, either ground in honey or as an infusion in hot milk. The seed oil can be used for illumination and soap making. Additionally, limited awareness and conservation efforts have further contributed to its threatened status. Recognizing the importance of preserving this valuable plant species is crucial for maintaining biodiversity and ensuring its availability for future generations. Furthermore, this review explores the potential benefits of Lepidium sativum in different domains. Its nutritional value and health benefits make it a promising candidate for addressing malnutrition and improving overall well-being. The presence of bioactive compounds suggests its potential use in functional foods, pharmaceuticals, and natural medicines for various ailments. Moreover, Lepidium sativum exhibits antimicrobial and insecticidal properties, offering potential applications in agriculture and pest control. The current review discussed the nutritional, potential benefits and pharmacological effects of Lepidium sativum.

Favorable Impact of Azithromycin on Patients in the Intensive Care Unit with Coronavirus Disease 2019: Insights from the First Wave Using a Japanese Database

BackgroundAzithromycin has favorable effects on critical respiratory diseases owing to its antimicrobial and anti-inflammatory properties. During the early stages of the coronavirus disease 2019 (COVID-19) pandemic, azithromycin was frequently administered before specific treatments were developed. However, the efficacy of this treatment has not been verified. We retrospectively investigated the effects of its intravenous (IV) administration in patients with severe/critical COVID-19 using the National Administrative Database of Japan during the first wave (February–April 2020). MethodsPatients were categorized based on whether they received IV azithromycin within three days of hospitalization. An overlap weighting method with estimated propensity scores was used to reduce bias. ResultsAmong the 830 patients with severe/critical COVID-19, 148 (17.8%) received azithromycin, and 682 (82.2%) did not. After adjustment, the use of azithromycin was associated with a shorter duration of intensive care unit (ICU) management (-3.48 days, 95% confidence interval [CI]: -4.59 to -2.38). However, other endpoints, including mortality rate, duration of mechanical ventilation, and duration of hospital stay, did not suggest any associations. Furthermore, of the 115 ICU patients, 27 (23.5%) were treated with IV azithromycin and 88 (76.5%) were not. After adjustment, azithromycin was associated with favorable outcomes, including reduced in-hospital mortality (odds ratio [OR], 0.45, 95% CI: 0.22 to 0.92), 30-day mortality (OR, 0.46, 95% CI: 0.22 to 0.94), and a shorter duration of ICU management (-2.94 days, 95% CI: -5.15 to -0.73). ConclusionWe verified that IV azithromycin was associated with favorable impact in patients with COVID-19 requiring ICU management.

Exploring the Medicinal Potential of Hyptis suaveolens (Lamiaceae): A Comprehensive Review of Phytochemicals, Pharmacological Properties, and Drug Development Prospects

Hyptis suaveolens is a widely well-known species of the Lamiaceae family. This plant is regarded as noxious exotic invasive weeds. It has medicinal and insecticidal properties and is used in traditional medicine to treat various illnesses. This review examines the potential utility of the understudied plant species H. suaveolens for future drug development and design, the existence of medicinally significant secondary metabolites, and their potential pharmacological and pharmacognostic importance . Search engines such as Science Direct, Google Scholar, Springer Link, PubMed, and Scopus were used to find data and information to write this paper. Alkaloids, essential oils, terpenoids, sterols, tannins, saponins, and flavonoids are only a few of the phytochemicals abundant in H. suaveolens that have therapeutic value . These bioactive compounds possess diaphoretic, analgesic, gastroprotective, antiviral, antimicrobial, anticancer, antispasmodic, antirheumatic, antibacterial, antiseptic, anti-inflammatory, and antiulcer properties. Among the polyphenolic substances found in high concentration in H. suaveolens are methyl rosamarinate, p-coumaric acid, p-hydroxybenzoic acid, vanillic acid, prodelphinidins, syringic acid, profisetinidins, protocatechuic acid, gentisic acid, caffeic acid, rosamarinic acid, and proanthocyanidins. In H. suaveolens, some terpenoid bioactive compounds such as ursolic acid, methyl suaveolate, suaveolic acid, beta-sitosterol, and suaveolol are available in different parts of the plant. Some essential compounds, such as Linoleic acid, Palmitic acid, and Oleic acid, are found in the seed oils of H. suaveolens. Pentacyclic triterpenoid and ursolic acid from H. suaveolens have been reported to have effective antiviral response s. The plant extract is used to prepare silver and copper nanoparticles for different biological activities. Due to these characteristics, the plant may be able to treat resistant and recently discovered bacterial and viral infections instead of conventional medications.

Facile fabrication and characterization of carboxymethyl cellulose loaded with TiO2NPs hydrogel as a promising disinfectant for eliminating the dissemination of waterborne pathogens through wastewater decontamination

The purpose of this work was to develop and characterize an intriguing hydrogel called TiO₂NPs@CMC hydrogel, which is composed of carboxymethyl cellulose (CMC) and loaded with titanium oxide nanoparticles (TiO₂NPs) for effective waterborne pathogen disinfection in wastewater. The TiO₂NPs were synthesized through hydrolysis and peptization, incorporated into a CMC matrix, and subsequently cross-linked with calcium chloride (CaCl₂). Characterization through TEM, FTIR, and SEM validated the development of a porous structure, efficient incorporation of TiO₂NP, and successful crosslinking. In this study, TiO2NPs were prepared and affirmed the significant particle distribution with a small size using TEM. The TiO₂NPs@CMC hydrogel exhibited significant antimicrobial and antibiofilm properties against various pathogens, such as Salmonella typhi, E. coli O157, Shigella dysenteriae, Enterococcus faecalis, Bacillus cereus, and Candida albicans, with highest inhibition zone diameters of up to 29 mm for S. typhi. The inhibitory effect demonstrated that the hydrogel significantly decreased bacterial populations at 100 μg/mL concentrations. The hydrogel demonstrated a 2.7-log reduction in microbial counts in sewage water within 120 min, achieving complete inactivation of pathogens at a concentration of 2xMIC within 180 min. The biofilm inhibition rate reached 87.6 % against B. cereus. Toxicity assessments demonstrated significant biocompatibility, with no negative effects noted in environmental applications. The findings indicate that TiO₂NPs@CMC hydrogel is a viable option for sustainable wastewater treatment, providing an efficient, safe, and environmentally friendly method for the removal of waterborne pathogens and the prevention of biofilm formation.

Functional composite films incorporating triphala-derived carbon dots for extending chicken preservation

Triphala-based carbon dots (T-CDs) were successfully prepared using a simple one-step hydrothermal method. T-CDs were characterized by absorbance, fluorescence, Fourier-transform infrared, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. T-CDs showed bright blue fluorescence at 434 nm upon excitation at 360 nm. Functional composite films were prepared using poly(vinyl alcohol) and gelatin mixture by incorporating T-CDs and applied as a packaging film to extend the shelf life of chicken. The antibacterial activity of T-CDs against Listeria monocytogenes and Staphylococcus aureus was evaluated using well diffusion and colony count methods. T-CDs were evenly dispersed throughout the PVA/Gel solution to form a dense and uninterrupted film. They also formed strong bonds with polymer chains, which improved the tensile strength of the film from 32.44 to 42.70 MPa. Furthermore, the presence of T-CDs significantly enhanced the UV-blocking ability of the PVA/Gel films, achieving 99.7 % for UV-B and 97.2 % for UV-A. In addition, the PVA/Gel/T-CDs composite films showed excellent antioxidant, antimicrobial and UV-barrier properties, extending the shelf life of chicken. Therefore, the PVA/Gel/T-CDs composite films showed great potential as an active food packaging material to extend the shelf life and preserve the visual quality of packaged meat.

6-Paradol exhibits antimicrobial, anti-quorum sensing and anti-virulence capacities on gram-negative bacteria: In vitro and in vivo studies

Grains of paradise, which are native to Africa, contain 6-paradol, an antibacterial compound found in plants of the Zingiberaceae family. In this study, the antimicrobial and anti-virulence properties of 6-paradol were evaluated against significant Gram-negative bacteria. The assessment encompassed the impact of 6-paradol on the bacterial cell membrane, efflux mechanisms, bacterial motility, biofilm formation, and extracellular enzyme production. The findings demonstrated promising anti-quorum sensing activity of 6-paradol. Moreover, the outcomes unveiled that the antimicrobial activity of 6-paradol is primarily stems from its substantial influence on the bacterial cell membrane and efflux mechanisms. Furthermore, 6-paradol exhibited potential anti-virulence activities by effectively reducing the generation of biofilm and virulent enzymes, impeding bacterial motility, and inhibiting in vivo bacterial pathogenesis. These anti-virulence effects were attributed to the compound's interference with quorum sensing systems and the downregulation of genes associated with these systems. Additionally, when combined with antibiotics, 6-paradol demonstrated synergistic effects. In conclusion, 6-paradol possesses noteworthy anti-virulence activities and can be employed as an auxiliary alongside antibiotics for treating aggressive Gram-negative infections. This highlights its potential as a valuable addition to therapeutic strategies.

The Impact of Tea Consumption on Cardiovascular Health

Tea is a popular beverage that comprises various antioxidants. Tea is the second most consumed beverage in the world after water. The three ideal types of tea include black, white, and green teas. Catechin, Epicatechin gallate, and Epicatechin are the striped flavonoids coeval in the tea. These flavonoids are freed as a rich source for blood circulation in the heart. Tea possesses antiinflammatory, anti-neoplastic, anti-arthritic, anti-thrombotic, antimicrobial, anti-platelet aggregation, anti-cholesterol, anti-hyperglycemic, and immuno-protective properties. Modern empowering research studies contemplate that minimal consumption of tea can also be of advantage to the cardiovascular system (CVS) as it modulates oxidative stress. Consumption of tea is beneficial for cardiovascular diseases such as atherosclerosis, coronary artery disease, aortic aneurysms, peripheral artery disease, stroke, ischemic heart disease, and cardiomyopathy. Consumption of excess tea may also be detrimental to health, and we highlight different types of tea. The main aim of the present narrative review is to highlight the natural compounds present in tea and discuss their mechanism of action on the cardiovascular system. Based on evidence gathered from published literature, it is thereby concluded that tea is a popular drink with potential cardiovascular health benefits.

Mucoadhesive polyelectrolyte complexes of fucoidan and chitin nanowhiskers to prolong the antiprotozoal activity of metronidazole

The improvement of the specific pharmacological activity of agents with antimicrobial and antiprotozoal properties (e.g. metronidazole, MET) is of interest for clinical applications in the treatment of bacterial infections. In this work, we prepared the polyelectrolyte complexes (PEC) based on chitin nanowhiskers (CNW) and fucoidan (FUC) with hydrodynamic diameters of 244 and 816 nm, a ζ-potential of about −22 mV and good mucoadhesive properties. The incorporation of MET into PEC particles promoted the sustained release of MET for 10 h and maintained the antiprotozoal activity against clinical isolates of Trichomonas vaginalis for up to 10 h. At concentrations of 1–3 mg/mL (HeLa cell line), the CWN-FUC-MET particles showed no cytotoxicity. The sustained drug release rate, combined with pronounced mucoadhesive properties, improved pharmacological activity, and non-cytotoxicity makes the developed biopolymer delivery systems promising candidates for further clinical trials.

Cu2O/H2Ti3O7/Cellulose biohybrid film with efficient photocatalytic and antibacterial activities in solar-driven environmental decontamination

Increasing efforts have been devoted to cellulose-based multifunctional biomaterials for environmental applications. In this study, solvothermal method combined with impregnation reduction process of Cu2+ has been developed to create versatile Cu2O/H2Ti3O7/CP (cellulose paper) biocomposite films that demonstrates efficacy in treating wastewater from organic compounds, disinfecting it from microbes and also purifying the air from volatile organic compounds (VOCs). H2Ti3O7 nanosheets decorated with Cu2O nanoparticles exhibit an excellent visible-light responsibility. Furthermore, the Cu2O/H2Ti3O7/CP biocomposite film demonstrated enhanced efficacy in removing aniline in the liquid phase and 1-propanol in the gaseous phase compared to the H2Ti3O7/CP. This enhanced photocatalytic activity is primarily due to the synergistic effect between Cu2O and H2Ti3O7, which suppresses the recombination of charge carriers and improves their mobility. Reuse tests confirm the stability of the prepared hybrid photocatalyst. Moreover, the biocomposite exhibits good antimicrobial properties, which contributed to the effective inactivation of Escherichia coli. This proves its versatility as a photocatalyst for a broad range of biological and environmental applications.

The effects of varying ingredients combination and boiling time on total phenolic content, antioxidant activity, and antimicrobial properties of lemongrass-ginger tea

This study was aimed at exploring the effect of varying lemongrass-ginger combinations, and boiling time on total phenolic contents (TPC), antioxidant activity, and antimicrobial efficacy of lemongrass-ginger tea. Lemongrass-ginger tea was produced by varying the percentage of lemongrass (25 %, 50 %, and 75 %) and boiling times (5, 10, and 15 min). The antioxidant activity of the lemongrass-ginger tea samples was investigated using the DPPH and ABTS assays whereas the TPC was determined using the Folin-Ciocalteau method. The antimicrobial activities were investigated by measuring the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) of the tea against selected microorganisms, and its combinatory effects with antimicrobial drugs. The lemongrass-ginger combination and the boiling time significantly affected antioxidant potential, TPC, and antimicrobial activities. TPC measured ranged between 966.7 ± 90.20 to 1761.3 ± 81.70 μgGAE/g whereas DPPH antioxidant activities varied from 43.97 ± 14.99 % to 75.20 ± 8.55 %. The highest values of TPC and DPPH were 1761.3 ± 81.70 μgGAE/g and 75.20 ± 8.55 % and were recorded by 75 % lemongrass-ginger combination boiled for 15 min. Furthermore, differences in lemongrass-ginger combination and boiling times resulted in varying antimicrobial activities against the test microorganisms. The lowest MBC was recorded for 50 % lemongrass boiled for 10 min against C. albicans, 75 % lemongrass boiled for 15 min against K. pneumoniae and S. typhi, and 25 % lemongrass against E. coli. Additionally, varying ingredient proportions and boiling times affected the combinatory effect of the tea with antimicrobial drugs. However, the exact effect depends on the proportion of ingredients used and the boiling times.

Efficacy of a gelling-fibre dressing and a gelling-fibre dressing with silver nanoparticles at controlling exudate and infection: a 4-week multicentre clinical evaluation.

Suprasorb Liquacel Pro (standard test dressing) and Suprasorb Liquacel Ag (test dressing with silver nanoparticles) are absorptive gelling-fibre dressings designed to manage wound exudate levels and promote moist wound healing, with the latter having additional antimicrobial properties. To assess the impact of the test dressing on healing, exudate levels and signs of infection. Patients with moderately-to-highly exuding hard-to-heal wounds of any type were dressed with the standard test dressing or the test dressing with silver nanoparticles if they showed covert or overt signs of local infection. Comparative data were collected at baseline and 4-week conclusion. Adverse events and patient and professional opinions were also reported and collated. There were 19 patients with lower-limb wounds of various types present for a mean of 26 months. At baseline, most wounds were deteriorating or static (68%), while at conclusion most were improving or healed (84%), with additional indicators of improved healing. The number of patients with moderate-to-high exudate levels decreased from 84% to 53%. The 15 patients using the test dressing with silver nanoparticles saw reductions in covert signs of infection from 93% to 80%, overt signs of infection from 33% to 13% and antibiotic use from 13% to 7%. On average, the test dressings were effective in managing and reducing the barriers to healing, including high exudate, infection and biofilm, and in restarting stalled healing.

Green synthesis of silver nanoparticles from supercritical CO2 mediated Lagerstroemia speciosa extract: Characterization, antimicrobial and antibiofilm activity

In the current study, optimal supercritical fluid extract (SFE) of Lagerstroemia speciosa (LS) leaves at pressure 29.59 megapascal (MPa), temperature 89.50 ºC and extraction time 53.85 min. was used to extract phenolic compounds for the synthesis of silver nanoparticles (AgNPs). The synthesis was studied for 0-20 hrs. Initially the synthesis of nanoparticles (SFELS-AgNPs) was confirmed using UV -spectroscopy. It demonstrated a maximum surface plasmon resonance at 430 nm. The crystallite dimension of nanoparticles was determined using X-ray diffraction (XRD) (13.47 nm), Transmission electron microscopy (TEM), zeta potential analysis and energy-dispersive X-ray analysis (EDAX) were used to analyze the morphology, surface charge and presence of differential elements in SFELS-AgNPs respectively. Developed nanoparticles revealed antimicrobial activity against two gram-positive viz. Staphylococcus aureus and Bacillus cereus, and three gram-negative bacteria viz. Klebsiella pneumonia, Pseudomonas aeruginosa and Escherichia coli. The nanoparticle showed a minimum inhibitory concentration (MIC) of 64 μg/ml whereas the minimum bactericidal concentration (MBC) 128 μg/ml against K. pneumonia. They significantly inhibited K. pneumonia biofilm formation which was confirmed using scanning electron microscopy (SEM). The results were encouraging compared to the standards drug Chloramphenicol and other controls. The generated nanoparticles have highly effective antimicrobial properties against pathogenic bacteria.

In vitro sustained release modeling and antimicrobial properties of the Persian gum-based bio-nanocomposite loaded with electrosprayed gliadin containing cinnamon essential oil

In vitro sustained release modeling and antimicrobial properties of the Persian gum-based bio-nanocomposite loaded with electrosprayed gliadin containing cinnamon essential oil