Inhibition Zone Diameter Research Articles

Evaluation of Antioxidant and Antimicrobial Activity of Ethanolic Extract of Medicinal Plants Baccaurea Ramiflora and Microcos Paniculata.

The present study was undertaken to investigate the antioxidant and antimicrobial effect of ethanolic leaf extract of Baccaurea ramiflora and Microcos paniculata. DPPH radical scavenging activity, Nitric oxide scavenging activity, Super oxide anion radical scavenging activity, Reducing power assay were used to assess antioxidant efficacy. Zone of Inhibition determination by Agar well diffusion assay was used to assess antimicrobial activity. The Baccaurea ramiflora and Microcos paniculata leaves extracted with different solvents such as petroleum ether, chloroform, ethanol and water among that in leaves ethanolic extract produce 10.78, 10.38 percentage yield respectively. Both the extracts subjected for phytochemical investigation revealed the presence of alkaloids, glycosides, tannins, saponins, proteins and flavonoids. Ethanolic extract of Baccaurea ramiflora showed maximum inhibition zone diameter was obtained in Salmonella typhi (Gram-negative bacteria) with diameter 29 mm and 25 mm respectively at 200mg/ml and 100mg/ml. Similarly, Ethanolic extract of Microcos paniculata showed minimum inhibition zone diameter compare to Baccaurea ramiflora was obtained in Salmonella typhi (Gram-negative bacteria) with diameter 23 mm and 19 mm respectively at 200mg/ml and 100mg/ml. Ethanolic extract of Baccaurea ramiflora showed maximum inhibition zone diameter was obtained in Aspergillus fumigates with diameter 25 mm and 22 mm respectively at 200mg/ml and 100mg/ml. Similarly, Ethanolic extract of Microcos paniculata showed minimum inhibition zone diameter compare to Baccaurea ramiflora was obtained in Aspergillus fumigates with diameter 21 mm and 19 mm respectively at 200mg/ml and 100mg/ml. The current findings point to Baccaurea ramiflora and Microcos paniculata antioxidant and antimicrobial properties. However future studies should be designed to isolate the active constituents responsible for the specified effect.

Evaluation of Mechanical Performance and Antibacterial Efficacy of Alumina‐Silver Nanoparticle‐Reinforced Bioepoxy for Dentistry

The lack of mechanical and antibacterial characteristics of most dental resins impedes their broader applications in dentistry. Therefore, this study aimed to enhance biocompatibility and mechanical and antibacterial features of bioepoxy (BE) to be used in dentistry. The properties of BE were assessed prior to and after reinforcing with several loading of nanoalumina (Al2O3)/nanosilver (AgNPs) particles. The mechanical characteristics were evaluated using three‐point bending and Izod impact tests. The morphologies and surface roughness of pristine BE and nanoalumina/nanosilver‐reinforced BE composites were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. The influence of these additives on the BE antibacterial properties were evaluated using the agar diffusion approach. The flexural strengths of the modified BE composites with nanoalumina/nanosilver particles were higher than those for additive‐free BE, and their values were considerably dependent on filler loading. The impact strength and flexural strength of composite materials were greater at hybrid reinforcement loading of 2 wt%. At such ratio, an increase of approximately 33.8% was obtained in the flexural strength compared with that of blank BE. On the other hand, the incorporation of higher proportions of nanoparticles led to a decrease in overall properties of composites, yet they were higher than that of additive‐free BE. The flexural strength for the composite containing 0.5 wt% AgNPs and 3.5 wt% Al2O3 was higher than the value stated for the nanoparticles‐free BE by 18.7%. Furthermore, the composite comprising 0.5 wt% of each of the nanoparticles had a great ability to alleviate the spreading of Staphylococcus aureus and Escherichia coli when compared with the resin and composites with other formula. For instance, the diameter of inhibition zone (DIZ) against Staphylococcus aureus of the aforementioned composite increased about 16% than that of additive‐free BE. All these features make this composite system a promising candidate in biomedical applications especially in dental related applications.

Uma promissora estrutura à base de poli (e-caprolactona)/grafeno como antibacteriana na regeneração do tecido ósseo

Abstract Scaffolds are 3D biomaterials that provide an environment for cell regeneration. In the context of bone remodeling, poly(e-caprolactone) (PCL) combined with graphene has been developed as the scaffold. It is imperative for scaffolds to possess antibacterial properties in order to properly reduce the risk of potential infections.Therefore, this study aims to analyze the antibacterial characteristics of PCL/graphene scaffolds against Staphylococcus aureus (S. aureus) and Porphyromonas gingivalis (P. gingivalis) in vitro. In this study, five different groups were used, including PCL (K-), Amoxicillin (K+), PCL/Graphene 0.5 wt%, PCL/graphene 1 wt% and PCL/Graphene 1.5 wt%. All experiments were performed in triplicates and were repeated three times, and the diffusion method by Kirby-Bauer test was used. The disc was incubated with S. aureus and P. gingivalis for 24 hours and then the diameter of the inhibition zone was measured. The results showed that the PCL/graphene scaffolds exhibited dose-dependent antibacterial activity against S. aureus and P. gingivalis. The inhibition zone diameter (IZD) against S. aureus of PCL/graphene 1 wt% was 9.53 ± 0.74 mm, and increased to 11.93 ± 0.92 mm at a concentration of 1.5 wt% of graphene. The PCL/graphene scaffold with 1.5 wt% exhibited a greater inhibitory effect, with an IZD of 12.56 ± 0.06 mm against P. gingivalis, while the inhibitory activity of the 1 wt% variant was relatively lower at 10.46 ± 0.24 mm. The negative control, PCL, and PCL/graphene 0.5 wt% exhibited no antibacterial activity sequentially (p = 1). Scaffolds of poly(e-caprolactone)/graphene exhibited an antibacterial activity at 1, and 1.5 wt% on S. aureus and P. gingivalis. The antibacterial properties of this scaffold make it a promising candidate for regenerating bone tissue.

Isolation and Characterization of Active Alkaloid Compounds from Cinnamomum Verum Cortexes and Proof of their Medicinal Efficacy against Pathogenic Fungus Alternaria Alternate Causing Upper Respiratory Tract Inflammatory Disease

Six alkaloid compounds were isolated (the discovery of a natural drug, which is a combination of the six alkaloid compounds). Alkaloids viz., 1,3,5-Triazine-2-carboxylic acid, 4-amino-6-methyl; 1,2,4-Triazino[5,6-E][1,2,4]-triazine-3,6-dione, hexahydro; 2-(4,5-Dihydro-3-methyl-5-oxo-1-phenyl-4-pyrazole)-5-nitrobenzoic acid; 4-metyl-3,4-dihydro-[1,2,3] trizolo [4,5-d] pyrimidine-5,7-dione; Propanoic acid-3-(perhydro-2,5-dioxo-imidazol [4,5-d] imidazole-1-yl) and 1,2,3-Triazolo[4,5-f] benzotriazole- 4,8(4H,8H)-dione, were isolated from Cinnamomum verum cortexes by using ethanolic acetic acid, sulphuric acid, and ammonia solvents, and they were characterized by using preliminary qualitative tests, gas chromatography-mass spectrumGC-MASS. The medicinal efficacy was studied for these six alkaloidic compounds theoretically by using the Autodock program and the results showed the presence of high efficacy of the compounds. Then the medicinal efficacy was measured biologically for the six compounds mixture in vitro depending on the synergistic interaction principle by using various concentrations (5, 10, 15, 20, and 25 mg/ml) by using of agar diffusion technique. The results showed that the six alkaloidic compounds’ mixture is biologically active against Alternaria alternate fungus, where the inhibition zone diameters were recorded equal to 27, 33, 41, 45, and 49 mm respectively towards the pathogenic fungus. Also, cytotoxicity tests for the different concentrations of six active alkaloid compounds mixture proved there is no toxic effect belonging to them towards red blood cells, and no hemolysis effect appeared in blood cells. Therefore, six alkaloid compounds isolated from Cinnamomum verum cortexes can be used as active drugs for the treatment of various diseases especially those caused by pathogenic fungi represented by Alternaria alternate, without any side effects.

Characterization of metallic nanoparticles synthesized via green synthesis from Viola odorata and their application in azo-dye biodegradation: A circular economy approach

The study aimed to synthesize nanoparticles from Viola odorata extract to biodegrade azo-dyes, enabling a circular economy approach to waste management in industries that utilize these dyes. The study utilized UV–visible spectroscopy and scanning electron microscopy (SEM) to confirm the synthesis and analyze the characteristics of the nanoparticles. The stability of the nanoparticles was assessed through the examination of four factors: the impact of NaCl, storage conditions, temperature, and pH. Plant-based nanoparticles were mixed with dye solutions, incubated, and analyzed for dye degradation using UV–Vis spectroscopy. Antibacterial and antifungal activity were assayed by disc diffusion method. UV–Vis spectrum confirms the synthesis of Ag-NPs at 450 nm, Au-NPs 533 nm, Co-NPs 246, Fe-NPs 255 nm. Ag-NPs had an average size of 18.2, Co-NPs 22.86 nm, Au-NPs 14. 9 nm and Fe-NPs 43 nm and all nanoparticles are spherical in shape. The nanoparticles exhibited excellent stability under varying temperature, pH, salt concentrations, and during six-months storage, these stable nanoparticles degraded methyl orange absorbance from 2.7 to 1.5. Methyl red was also degraded and its absorbance decreased from 2.8 to 1.25. The study found that all the synthesized nanoparticles displayed good antibacterial activity against both Gram-negative and Gram-positive bacteria. However, the gold nanoparticles (Au-NPs) demonstrated the highest potency, particularly against Pseudomonas aeruginosa, with an inhibition zone diameter nearly matching that of the commercial antibiotic Streptomycin. Similarly, the antifungal assay revealed that the Au-NPs exhibited the strongest activity against the tested fungal strains compared to the other nanoparticle types.

Unveiling the Antibacterial Properties of Statins: An In Vitro Study on Helicobacter pylori

Background. Helicobacter pylori (H. pylori), a widespread bacterial pathogen, is associated with various gastrointestinal diseases, including gastric cancer. Statins, widely prescribed cholesterol‐lowering agents, have demonstrated pleiotropic effects, including potential antimicrobial properties. This in vitro study investigated the direct antibacterial effects of three clinically approved statins, simvastatin, atorvastatin, and rosuvastatin, against H. pylori isolates. Methods. H. pylori strains were isolated from gastric biopsies of dyspeptic patients and identified by microbiological techniques. The minimum inhibitory concentrations (MICs) of statins were determined using the agar dilution method, and their antimicrobial activity was evaluated by the disc diffusion method using different concentrations of simvastatin, atorvastatin, rosuvastatin, tetracycline, and amoxicillin. Scanning electron microscopy (SEM) was employed to examine the morphology of H. pylori cells. Results. The minimum inhibitory concentration (MIC) values (μg/mL) of atorvastatin, rosuvastatin, simvastatin, tetracycline, and amoxicillin against H. pylori were 240 ± 20, 450 ± 20, 460 ± 15, 155 ± 30, and 140 ± 20, respectively. In the disc diffusion assay, atorvastatin and rosuvastatin produced significantly larger inhibition zones compared to simvastatin at all concentrations tested (p < 0.05). The inhibition zone diameters (mm) increased with higher statin concentrations, ranging from 9 ± 1.4 to 13 ± 1.4 for atorvastatin, 8 ± 0.9 to 11 ± 0.6 for rosuvastatin, and 5 ± 1.3 to 6 ± 1.4 for simvastatin at the highest tested concentration (1200 μg/ml). SEM analysis revealed the characteristic spiral morphology of H. pylori cells. Conclusion. Statins demonstrated varying degrees of antibacterial activity against H. pylori isolates, with atorvastatin exhibiting the highest potency. While the observed effects were lower than those of conventional antibiotics, these findings suggest the potential of statins as adjunctive agents or alternative therapeutic options, warranting further investigation through in vivo studies and clinical trials.

A novel biodegradable nanocrystalline Zn alloy with exceptional biocompatible and antibacterial properties

The development of biodegradable Zn alloys with comprehensive performance for biomedical applications is still challenging. Hence, the nanocrystalline Zn–Cu–Sr–Li alloys were prepared by alloying design and multi-pass high-speed hot rolling. The Zn–3Cu-0.2Sr-0.4Li alloy achieved nanoscale microstructures, resulting in high strength and an ideal corrosion rate that is more suitable for tissue repair cycles. Scanning Kelvin probe force microscopy analysis revealed the potential from high to low was ranked as: ε phase > SrZn13 phase > Zn grains > β phase. The nanoscale Zn grains and β particles formed numerous microcells, enhancing the microgalvanic corrosion effect. The Sr ions could be released more efficiently during the degradation in Li-containing alloys, which endowed the alloys with outstanding biocompatibility. Besides, the synergistic release of Zn ions and Cu ions during alloy degradation endowed the alloy with excellent antimicrobial ability against Staphylococcus aureus (inhibition zone diameter ≈ 7.5 mm). The antimicrobial ability of Zn–3Cu–0.2Sr–0.4Li alloy was superior among the reported biodegradable Zn alloys. These results demonstrated nanocrystalline Zn–Cu–Sr–Li alloys have comprehensive performance and broad application prospects in biodegradable bone implants, providing the experimental and theoretical basis for future research in the biomedical field.

BENZAMINE DERIVATIVES: SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY STUDY

: Our study is included the synthesis of a number of benzamide drivatives through two chemical processes. The first is the benzoylation of some aromatic amines containing a pyrimidine or a pyrazoline ring in their structures (A-G) using benzoyl chloride or p-chloronbenzoyl chloride in the presence of 1,4- dioxan as solvent productive (N1-N6, N13-N16) derivatives. The second is the tosylation of (N2-N6, N15) by p-toluene sulfonyl chloride in the presence of pyridine as catalyst and base at room temperature to produce (B1-B6 ) derivatives . The products have been characterized by IR, 1H-NMR ,13 C-NMR and mass spectroscpies and the physical properties of the products are recorded . The spectral data confirmed the validity of the benzamide derivatives. Also the work is included the study of antimicrobial activity of the synthesized compounds represented by determining the inhibition diameter zone (IZ), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) given by these compounds against the test organisms Staphylococcus aureas (Gr+ positive) and Escherichia coli (Grnegative). Furthermore, the results of MIC and MBC were compared with those of some common antibiotics such as tetracycline, ampicillin and streptomycin. This comparison showed that it is possible to use the synthesized derivatives as antimicrobials

Exploring non-antimicrobial agents as antibiotic alternatives: an in vitrostudy

Background:Microorganisms cause periapical and pulpal disorders, making root canal treatment (RCT) essential. Due to complex canal anatomy, bacteria may persist despite cleaning. Intracanal medicaments, such as calcium hydroxide and chlorhexidine, help eliminate residual bacteria, reduce inflammation, and enhance treatment outcomes by improving disinfection and compatibility.Aim:To assess the antimicrobial effectiveness of Triple Antibiotic Paste (TAP), Modified TAP, Sertraline (SSRI), Atorvastatin and the combination of Atorvastatin and Sertraline against Enterococcus faecalis.Materials and methods:A total of 30 samples were made, with 6samples from each group: TAP, Sertraline, Atorvastatin, Modified TAP, and Sertraline + Atorvastatin. The antimicrobial efficacy of the medicaments was evaluated using an agar well diffusion test by measuring inhibition zones around the medicaments. Statistical analysis included one-way ANOVA, with significance set at p < 0.05.Results:A significant difference (p=0.001) in the diameter of growth inhibition zones was observed. The maximum inhibitory zone was found in Group 5: Sertraline+Atorvastatin.Conclusion:The combination of sertraline and atorvastatin demonstrated superior antimicrobial efficacy compared to modified TAP, TAP, sertraline, and atorvastatin used alone.

Antimicrobial soap development from leaf extract of Rhinacanthus nasutus

Bacterial skin infections are most prevalent in humans. These skin infections can be easily prevented by the topical application of herbal soaps produced from the medicinal plants. Medicinal plants contain natural bioactive compounds with a variety of biological potential that can be used to incorporate into a basic soap formulation. This study aims to prepare the antibacterial soap using leaf extract of local medicinal plant, Rhinachantus nasutus. The leaf extract was prepared by maceration extraction using methanol as solvent. The antibacterial and antifungal activities of the leaf extract and herbal soap were evaluated using the disc diffusion assay against Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Yersinia enterocolitica, Methicillin-resistant Staphylococcus aureus (MRSA), Aspergillus niger and Candida albicans. The thump impression test was employed to test the effectiveness of the soap as antibacterial and antifungal soap. The results obtained from the current study revealed that the leaf extract of R. nasutus efficiently inhibited the growth of all test microorganisms at a concentration of 25 mg/mL with a diameter of inhibition zone ranging from 1.0 ± 0.1 mm to 2.5 ±0.1 mm, whereas a prepared soap with a similar concentration also inhibited all test microorganisms with an inhibition zone ranging from 0.7±0.1 mm to 1.3±0.1 mm. A thumb impression test result indicated a reduction in microbial development when using herbal soap. Leaf extracts of R.nasutus can be used to produce herbal soaps with remarkable antibacterial activity.

SYNTHESIS AND CHARACTERIZATION OF Mg, Cu-HAp USING CALCIUM FROM LOKAN SHELL (Geloina expansa) AND ITS ANTIBACTERIAL ACTIVITY

Hydroxyapatite (HAp) is the primary inorganic constituent found in bones and teeth. It possesses biocompatibility and bioactivity within the human body, while its mechanical qualities are somewhat inferior. Magnesium is a viable alternative to calcium in the composition of bone minerals. Copper is both an antibacterial agent and a vital metal within our bodies. This study aims to produce Mg, and Cu-HAp by employing the sol-gel process in situ utilising Lokan shell (Geloina. Expansa) as the source material. Additionally, the antibacterial properties of Mg and Cu-HAp will be evaluated. The lokan shell is utilized as a calcium source, containing 94.626% calcium oxide (CaO), for synthesizing hydroxyapatite (HAp) with a calcium-to-phosphorus ratio of 1.67. The X-ray diffraction (XRD) analysis revealed a distinct pattern at a specific angle of 2θ, following the ICDD (No.96-101-1243) standard. The FT-IR spectra suggest that the bending vibration of the PO4 3- functional group occurs at a wave number of 610 cm-1, whereas the asymmetrical stretching occurs at wave numbers between 1010-1036 cm-1. These observations suggest the presence of HAp content. The antibacterial test results demonstrated that Mg, Cu-HAp3, and Mg, Cu-HAp4 exhibited good antibacterial activity, as evidenced by inhibition zone diameters of 0.9 mm for Escherichia coli and 0.8 mm for Staphylococcus aureus. These findings indicate that Mg and Cu-HAp effectively possess antibacterial properties.

Antibacterial activity and mechanism of chelerythrine against Streptococcus agalactiae.

Streptococcus agalactiae (S.agalactiae), also known as group B Streptococcus (GBS), is a highly infectious pathogen. Prolonged antibiotic usage leads to significant issues of antibiotic residue and resistance. Chelerythrine (CHE) is a naturally occurring benzophenidine alkaloid and chelerythrine chloride (CHEC) is its hydrochloride form with diverse biological and pharmacological activities. However, the antibacterial mechanism of CHEC against GBS remains unclear. Thus, this study aims to investigate the in vitro antibacterial activity of CHEC on GBS and elucidate its underlying mechanism. The antibacterial effect of CHEC on GBS was assessed using inhibitory zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays, as well as by constructing a time-kill curve. The antibacterial mechanism of CHEC was investigated through techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM), measurement of alkaline phosphatase (AKP) activity, determination of Na+ K+, Ca2+ Mg2+-adenosine triphosphate (ATP) activity, observation of membrane permeability, and analysis of intracellular reactive oxygen species (ROS) and mRNA expression levels of key virulence genes. The results demonstrated that the inhibition zone diameters of CHEC against GBS were 14.32 mm, 12.67 mm, and 10.76 mm at concentrations of 2 mg/mL, 1 mg/mL, and 0.5 mg/mL, respectively. The MIC and MBC values were determined as 256 μg/mL and 512 μg/mL correspondingly. In the time-kill curve, 8 × MIC, 4 × MIC and 2 × MIC CHEC could completely kill GBS within 24 h. SEM and TEM analyses revealed significant morphological alterations in GBS cells treated with CHEC including shrinkage, collapse, and leakage of cellular fluids. Furthermore, the antibacterial mechanism underlying CHEC's efficacy against GBS was attributed to its disruption of cell wall integrity as well as membrane permeability resulting in extracellular release of intracellular ATP, AKP, Na+ K+, Ca2+ Mg2+. Additionally CHEC could increase the ROS production leading to oxidative damage and downregulating mRNA expression levels of key virulence genes in GBS cells. In conclusion, CHEC holds potential as an antimicrobial agent against GBS and further investigations are necessary to elucidate additional molecular mechanisms.

Antibacterial, Antibiofilm, and Tooth Color Preservation Capacity of Magnesium Oxide Nanoparticles Varnish (in vitro Study).

Antibacterial and antibiofilm properties of magnesium oxide nanoparticles (MgONPs) mixture assessed against Streptococcus mutans (S. mutans), in addition to examining MgONPs varnish impact on the preservation of the tooth color and inhibition of methylene blue diffusion to the enamel. MgONPs mixture was prepared in deionized water (DW), absolute ethanol (E), and rosin with ethanol (RE), named varnish. The antibacterial and antibiofilm capacities of MgONPs mixtures were tested by agar well diffusion, colony-forming unit (CFU), and biofilm inhibition microtiter methods in triplicate and compared to sodium fluoride varnish (NaF) and chlorhexidine mouthwash (ChX). A spectrophotometer was used to record basic tooth color. The artificial demineralization was initiated for 96 h. Then, experimental materials were applied to the corresponding group, and 10-day pH cycles proceeded. Then, the color was recorded in the same ambient environment. The methylene blue diffusion was evaluated by staining the samples for 24 h. After that, the diffusion test was calculated by a digital camera attached to the stereomicroscope. The agar well diffusion test expressed a significant inhibition zone with all MgONPs mixtures (p = 0.000), and maximum inhibition zone diameter associated with MgONPs-RE. The same finding was observed in the CFU test. Additionally, 2.5%, 5%, and 10% MgONPs-RE varnish showed strong biofilm inhibition capacity (p = 0.039) compared to NaF and ChX groups that inhibit biofilm formation moderately (p = 0.003). The study shows that the 5% MgONPs-RE varnish maintains basic tooth color with minimal methylene blue diffusion compared to NaF varnish (p = 0.00). Evaluating MgONPs as a mixture revealed antibacterial and antibiofilm capacity against S. mutans with a higher effect of MgONPs-RE varnish. Also, examining the topical effect of MgONPs-RE varnish on the preservation of the tooth color after pH cycle challenges and methylene blue diffusion to enamel confirmed the high performance of MgONPs-RE varnish at 5%.

Screening of antibiogram, virulence factors, and biofilm production of Staphylococcus aureus and the bio-control role of some probiotics as alternative antibiotics.

Food safety is a serious challenge in the face of increasing population and diminishing resources. Staphylococcus aureus is a critical foodborne pathogen characterized by its capability to secret a diverse range of heat-resistant enterotoxins. Antibiotic usage in dairy herds resulted in the occurrence of antimicrobial resistance (AMR) patterns among bacterial species, which were consequently transmitted to humans via dairy products. Lactic acid bacteria (LAB) produce bacteriocins, which provide an excellent source of natural antimicrobials with the further advantage of being environmentally friendly and safe. Detection of multidrug resistance (MDR) S. aureus isolates in concerned samples, molecular characteristics, biofilm production, and the inhibitory role of LAB against it. Random samples of raw milk and other dairy products were analyzed for S. aureus isolation. Phenotypic and genotypic assessment of AMR was performed, in addition to detection of classical enterotoxin genes of S. aureus. Finally, evaluation of the antimicrobial action of some Lactobacillus strains against S. aureus. Incidence rates of presumptive S. aureus in raw milk, Kariesh cheese, and yogurt samples were 50%, 40%, and 60%, respectively. The highest resistance of S. aureus was to Kanamycin (100%) and Nalidixic acid (89.3%), respectively. (78.66%) of S. aureus were MDR. 11.1% of S. aureus carried mecA gene. In concern with enterotoxins genes, PCR showed that examined isolates harbored sea with a percentage of (22.2%), while sed was found in (11.1%) of isolates. Regarding biofilm production, (88.88%) of S. aureus were biofilm producers. Finally, agar well diffusion showed that Lactobacillus acidophilus had the strongest antimicrobial action against S. aureus with inhibition zone diameter ranging from 18 to 22 mm. There is a widespread prevalence of MDR S. aureus in raw milk and dairy products. Production of staphylococcal enterotoxins, as well as biofilm production are responsible for public health risks. Therefore, installing proper hygienic routines and harsh food safety policies at food chain levels is substantial.

Antibacterial Activity of Extract Green Seaweed Ulva intestinalis in North Waters of Aceh

The appearance of bacterial resistance and pathogenic infections makes efforts to find new drugs as natural bacterial agents continue. One of them is through the utilization of marine organisms such as seaweed. Some studies show the content of seaweed bioactive compounds has potential in the pharmacological field. This study aims to determine the type of secondary metabolite compounds and antibacterial activity of ethanol extract of Ulva intestinalis. Seaweed extraction using the maceration method for 3 x 24 hours and antibacterial activities were tested by disc diffusion method. The results showed that there were 5 types of secondary metabolite compounds in the extract, namely alkaloids, flavonoids, glycosides, saponins, and steroids. The antibacterial activity test of seaweed extract against Propionibacterium acnes and Aeromonas hydrophila bacteria in the concentration range of 50% to 100% showed a moderate inhibition zone diameter

Structural, morphological, optical and antibacterial performances of rare earth (Sm)-doped ZnO nanorods

The significant rise of ultra-violet (UV) radiation and pathogenic infectious bacteria poses a serious threat to global health. Numerous researchers’ interests are attracted by novel materials with strong UV-blocking ability, antibacterial activity and low toxicity to other species. In this case, a simple wet chemical method with different annealing temperatures (400, 500, and 600 °C) was employed to create highly effective rare earth (Sm)-doped ZnO nanorods. The (101) plane of wurtzite ZnO shifts towards a lower angle with increasing annealing temperature, according to the X-ray diffraction (XRD) study findings, which additionally establishes the consequence of lattice expansion. Occurrence of doublet peaks of Sm 3d (Sm 3d5/2 and Sm 3d3/2) in the X-ray photoelectron spectroscopy (XPS) spectrum clearly validates the substitution of Sm3+ ions in the 500 °C-annealed samples. The 500 °C-annealed nanorods exhibit combined performances of the wide band gap, improved UV absorbance, and vivid green luminescent emission (563 nm). Additionally, the nanorods have favorable UV-blocking execution of 96% for UVA at 360 nm, 92% for UVB at 320 nm, and 57% for UVC at 225 nm, which is greater than the majority of ZnO-related materials that have been reported up to this date. Sm doping is also appropriate for improving bacterial inhibition against the two studied strains (Escherichia coli and Staphylococcus aureus), in addition to the intriguing features discussed above. Furthermore, with maximum inhibition zone diameters of 20 ± 0.72 and 18 ± 0.57 mm, respectively, these nanorods exhibit high inhibitory action against E. coli and S. aureus bacterial strains. The rare earth-doped material developed during the current experiment, which was annealed at 500 °C, could potentially serve as an effective replacement for UV-blocking and antibacterial material, especially for biomedical applications.

Antibacterial activity of chlorophyll polymeric form against test cultures S. aureus and E. coli

The increase in the number of microorganism strains with resistance to anti-bacterial and disinfecting agents is getting more and more prevalent and has become an issue when treating the human and animals diseases and carrying out measures for disinfection treatment. This problem can be solved by using photodynamic and light-independent therapy. In both areas, metalloporphyrins have been successfully used for many years. One of the most famous representatives of porphyrins is chlorophyll (Chl). This work aims to develop of Chl polymeric form by incorporation in poly(lactic acid) (PLA) and study its inhibitory effect against Staphylococcus aureus and Escherichia coli, which are known as contaminants of the mucous and skin epithelium of humans and animals. The preparation method of Chl polymeric form is presented. The degree of Chl incorporation into PLA was more than 98%. The assessment of antimicrobial activity was carried out by measuring the inhibition zone diameters after bacterial incubation for 24–96 h. It was shown that Chl and Chl-PLA at a dosage of 75 µg inhibited S. aureus significantly. The exclusively bacteriostatic effect on E. coli was observed. These results can be used in the development of dosage forms and disinfectants.

Ziziphora tenuior L. Essential Oil as a Bio‐Based Antimicrobial and Plant‐Based Preservative for Increasing the Shelf Life of Mayonnaise

The food industry is seeking alternatives to chemical additives and preservatives due to the increasing consumers’ demand for healthier food products. Ziziphora tenuior L. (Z. tenuior) is an aromatic medicinal plant that exhibits various biological properties such as antibacterial, antifungal, antioxidant and anti‐inflammatory properties. The aim of this study was to assess the impact of Z. tenuior essential oil (ZTEO) incorporation (700 μg/g) into mayonnaise on its stability, as well as to investigate the potential for replacing synthetic preservatives. The results demonstrated that the ZTEO extraction yield by the Soxhlet method was 3%. The GC‐MS analysis of ZTEO showed the presence of 36 different components, with pulegone (27.5%), borneol (16.5%), 1, 8‐cineole (9.8%), camphor (8.37%), β‐pinene (5.31%), and α‐pinene (4.64%) as the major compounds. Results of antimicrobial activity showed that the highest and the lowest minimum inhibitory concentration (MIC) values were obtained for Escherichia coli (700 μg/mL) and Saccharomyces cerevisiae (10 μg/mL). Also, the inhibition zone diameter increased by increasing the level of ZTEO, and Staphylococcus aureus (33 mm) and S. cerevisiae (36 mm) had the highest inhibition zone at level of 75%. Incorporation of ZTEO into mayonnaise prevented the growth of all microorganisms (bacteria, fungi, and yeast) during three months of storage. This indicates the potential of ZTEO as a natural preservative to replace synthetic preservatives. The results indicated the potential for incorporating ZTEO into mayonnaises and demonstrated the possibility of replacing commonly used preservatives with a natural alternative, offering consumers healthier food.

Unveiling the Launaea nudicaulis (L.) Hook medicinal bioactivities: phytochemical analysis, antibacterial, antibiofilm, and anticancer activities.

Commonly used antimicrobial agents are no longer effective due to their overuse or misuse. In addition, many medicinal plant extracts can combat infectious diseases due to their main active constituents or secondary metabolites. The current study aimed to assess the bioactivities of Launaea nudicaulis (LN) leaf extract (LE) against different multi-drug resistant (MDR) Pseudomonas aeruginosa (P. aeruginosa) isolates. The ethyl acetate extract of a Launaea nudicaulis (LN) leaf was analyzed using GC-MS, which identified 27 key bioactive compounds. The major constituents found were as follows: 7-acetyl-6-ethyl-1,1,4,4-tetramethyltetralin, isopropyl myristate, thiocarbamic acid, N,N-dimethyl, S-1,3-diphenyl-2-butenyl ester, hahnfett, cyclopentane acetic acid, 3-oxo-2-pentyl-, methyl ester, hexadecanoic acid, and dotriacontane. Our study demonstrated that the LN leaf was a rich source of other important phytochemicals, including phenolic acids, tannins, saponins, and steroids. The relative biosafety of the L. nudicaulis LE was determined from the elevated inhibitory concentration 50 (IC50) of 262 μg/mL, as calculated from the cytotoxicity assay against the Wi-38 normal cell line. Conversely, 12.7 and 24.5 μg/mL were the recorded low IC50 values for the tested extract against the MCF-7 and Hep-G2 cancerous cell lines, respectively, reflecting its potent activity against the tested cancerous cell lines. Microbiologically, the susceptible P. aeruginosa isolates to the tested extract showed a growth inhibition zone diameter, in the well diffusion assay, ranging from 11.34 ± 0.47 to 26.67 ± 0.47 mm, and a percent inhibition (PI) value of 50-106.2%, reflecting its acceptable activity. In addition, the broth microdilution assay recorded minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in the ranges of 15.625-1,000 μg/mL and 125-1,000 μg/mL, respectively. In conclusion, the L. nudicaulis LE revealed showed promising activity and high selectivity against P. aeruginosa. Moreover, the extract exhibited natural anticancer activities with safe low concentrations, indicating its potential as a superior candidate for future studies of its active constituents.

Endophytic fungi from medicinal plant Garcinia cowa Roxb. ex Choisy and their antibacterial activity

Endophytic fungi grow inside plant tissues and produce biologically active substances without harming the host plant. Endophytic fungi isolated from the roots, barks, and leaves of Garcinia cowa Roxb. ex Choisy, an ethnomedicinal plant commonly used in West Sumatera, Indonesia, are the focus of this research, which aims to evaluate their antibacterial activity. Traditional medicine has made extensive use of this plant’s various parts. In total, 14 endophytic fungal isolates were obtained from plant fragments of G. cowa that had undergone surface sterilization. After four to six weeks of cultivation in rice medium, the fungus isolate was extracted with ethyl acetate (EtOAc). Each EtOAc extract of fungus was tested for antimicrobial activity using Kirby–Bauer diffusion against Staphylococcus aureus, Escherichia coli, Methicillin Resistant S. aureus, and Candida albicans. The measurement results of the inhibition zone indicate that the GCA3 isolate of endophytic fungi exhibited significant inhibitory diameters and demonstrated potential as an antibacterial agent. The GCA3 strain showed an inhibition diameter zone of 15.05 } 0.51 mm against S. aureus, 14.68 } 0.5 mm against E. coli, and 13.48 } 0.15 mm against MRSA. None of the fungi extracts can inhibit the growth of C. albicans. The fungus GCA3 has been determined to be identical to Penicillium citrinum through macroscopic, microscopic, and molecular identification methods. The findings indicate that endophytic fungi from the Garcinia plant can generate antibacterial compounds. Hence, additional investigation is required to separate these bioactive compounds.