Isolation and biocontrol of bacteriophages from wastewater in the city of Lomé, Togo: potential application as a novel source for antimicrobial therapy

Background: Bacteriophages offer one of the most promising solutions to the challenges of antimicrobial resistance in bacteria. The aim of this study is to investigate bacteriophages as a source of new antimicrobial therapy. Methodology: Waste water samples were randomly collected from 8 different locations in the city of Lomé for bacteriophage isolation. The phages were isolated using multi-resistant clinical isolates (Escherichia coli 1642 and Staphylococcus aureus 0868) as hosts by means of a spot test. The host range of the phages was determined also by a spot test using 8 other clinical bacterial isolates including two reference strains (E. coli ATCC 25922 and S. aureus ATCC 29213). The virulence of the phages and their effects on bacterial growth were assessed by in vitro experiments using E. coli 1642 BBec phage suspension. Results: Isolation of phages by the spot test was positive only with the host E. coli 1642. A reduced host range was observed with the other bacteria. The BBec phage suspension showed a titer of 1.6 x 107 PFU/ml. Virulence studies revealed a latency time of less than 10 minutes, a degree of absorption of 87% and a burst size of 63 PFU/cell. The effect of BBec phage suspension on E. coli 1642 showed an almost total reduction in the population of E. coli 1642 after 4 hours. Conclusion: This study provided scientific data showing the antibacterial effect of a phage suspension (BBec) on a multi-resistant clinical isolate of E. coli 1642. This phage could therefore be explored as a candidate for the development of new antibacterial therapies.

Efecto antibacteriano del extracto hidroalcohólico de Solanum sessiliflorum Dunal (cocona) sobre Streptococcus mutans

Introducción: La búsqueda de nuevos extractos de origen vegetal con propiedades antibacterianas para mantener la salud bucal, es fundamental para el óptimo desempeño del personal militar. Objetivos: Evaluar el efecto antibacteriano del extracto hidroalcohólico de Solanum sessiliflorum Dunal (cocona) sobre Streptococcus mutans. Métodos: Estudio experimental in vitro y comparativo. Se realizó un ensayo fitoquímico preliminar del extracto hidroalcohólico de Solanum sessiliflorum Dunal. Se emplearon 48 placas de agar Müller-Hinton (Merck®), distribuidas en 6 grupos (n= 8): grupo I (agua destilada), grupo II (etanol al 70 %), grupo III (clorhexidina al 0,12 %), grupo IV (Solanum sessiliflorum Dunal al 25 %), grupo V (Solanum sessiliflorum Dunal al 50 %) y grupo VI (Solanum sessiliflorum Dunal al 75 %). Se utilizó la técnica de difusión con discos descrita por Bauer y Kirby; la cepa empleada fue Streptococcus mutans ATCC 25175 y las mediciones de los halos de inhibición se realizaron a las 24 horas, para determinar la actividad antibacteriana. Resultados: En el ensayo fitoquímico se detectaron compuestos fenólicos, antocianinas, quinonas y glicósidos cardiotónicos. Se comprobó el efecto antibacteriano del grupo VI (Solanum sessiliflorum Dunal al 75 %) con 19,831 ± 0,0553 mm (99,37 %), comparable con el de clorhexidina al 0,12 % (grupo III) 19,956 ± 0,0431 mm (100 %) sobre Streptococcus mutans ATCC 25175. Conclusiones: El extracto hidroalcohólico de Solanum sessiliflorum Dunal al 75 % presenta efecto antibacteriano in vitro sobre cepas de Streptococcus mutans ATCC 25175 con valores similares a clorhexidina al 0,12 % .

Introduction: The search for new extracts of plant origin with antibacterial properties to maintain oral health is essential for the optimal performance of military personnel. Objectives: To evaluate the antibacterial effect of the hydroalcoholic extract of Solanum sessiliflorum Dunal (cocona) on Streptococcus mutans. Methods: In vitro and comparative experimental study. A preliminary phytochemical assay of the hydroalcoholic extract of Solanum sessiliflorum Dunal was performed. Forty-eight Müller-Hinton agar plates (Merck®) were used, distributed in 6 groups (n= 8). Group I (distilled water), group II (70% ethanol), group III (0.12% chlorhexidine), group IV (25% Solanum sessiliflorum Dunal), group V (50% Solanum sessiliflorum Dunal) and group VI (75% Solanum sessiliflorum Dunal); the disc diffusion technique described by Bauer and Kirby was used; the strain used was Streptococcus mutans ATCC 25175 and the inhibition halos were measured at 24 hours to determine the antibacterial activity. Results: Phenolic compounds, anthocyanins, quinones and cardiotonic glycosides were detected in the phytochemical assay. The antibacterial effect of group VI (Solanum sessiliflorum Dunal 75%) was proven with 19,831 ± 0,0553 mm (99,37%), comparable to that of 0,12% chlorhexidine (group III) 19,956 ± 0,0431 mm (100%) on Streptococcus mutans ATCC 25175. Conclusions: The 75% hydroalcoholic extract of Solanum sessiliflorum Dunal shows in vitro antibacterial effect on Streptococcus mutans ATCC 25175 strains with values similar to 0,12% chlorhexidine.

Bilayer hydrogel dressing with lysozyme-enhanced photothermal therapy for biofilm eradication and accelerated chronic wound repair

Biofilms are closely associated with the tough healing and dysfunctional inflammation of chronic wounds. Photothermal therapy (PTT) emerged as a suitable alternative which could destroy the structure of biofilms with local physical heat. However, the efficacy of PTT is limited because the excessive hyperthermia could damage surrounding tissues. Besides, the difficult reserve and delivery of photothermal agents makes PTT hard to eradicate biofilms as expectation. Herein, we present a GelMA-EGF/Gelatin-MPDA-LZM bilayer hydrogel dressing to perform lysozyme-enhanced PTT for biofilms eradication and a further acceleration to the repair of chronic wounds. Gelatin was used as inner layer hydrogel to reserve lysozyme (LZM) loaded mesoporous polydopamine (MPDA) (MPDA-LZM) nanoparticles, which could rapidly liquefy while temperature rising so as to achieve a bulk release of nanoparticles. MPDA-LZM nanoparticles serve as photothermal agents with antibacterial capability, could deeply penetrate and destroy biofilms. In addition, the outer layer hydrogel consisted of gelatin methacryloyl (GelMA) and epidermal growth factor (EGF) promoted wound healing and tissue regeneration. It displayed remarkable efficacy on alleviating infection and accelerating wound healing in vivo. Overall, the innovative therapeutic strategy we came up with has significant effect on biofilms eradication and shows promising application in promoting the repair of clinical chronic wounds.

Research progress on antimicrobial peptides in terms of the prevention and treatment of dental caries / 口腔疾病防治

@#Antimicrobial peptides have antibacterial effects on various pathogenic microorganisms, including natural antimicrobial peptides and synthetic antimicrobial peptides. According to the structure of natural antimicrobial peptides, synthetic antimicrobial peptides can be obtained by recombining different functional domains, adjusting the original amino acid sequence, or completely redesigning the peptides from scratch. Antimicrobial peptides can inhibit the growth of various cariogenic microorganisms and the formation of microbial biofilms. They also reduce acid production and acid resistance of microorganisms. Natural antimicrobial peptide genes can be used as genetic susceptibility markers for predicting the development of caries, thus, showing potential applications in the prevention and treatment of dental caries. The instability of natural antimicrobial peptides and the inability to achieve targeted sustained release limit their application in the prevention and treatment of oral caries. Synthetic antimicrobial peptides can enhance their stability and the antibacterial effect. Synthetic antimicrobial peptides can also be polymerized with common oral adhesives to reduce the incidence of microleakage after filling treatment for caries and to prevent the occurrence of secondary caries. The pH-sensitive antimicrobial peptides are slowly released to promote remineralization in the process of caries. However, the safety and biocompatibility of synthetic antimicrobial peptides are worse than those of natural antimicrobial peptides. Moreover, the combined effect of antibacterial peptides and anticaries drugs, such as fluoride, is still uncertain. Therefore, in this paper, we will review the design methods, application and underlying mechanisms of antimicrobial peptides to introduce novel methods and ideas for the prevention and treatment of dental caries.

Synergistic effect of β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli in vitro / 生物工程学报

The widespread of tigecycline resistance gene tet(X4) has a serious impact on the clinical efficacy of tigecycline. The development of effective antibiotic adjuvants to combat the looming tigecycline resistance is needed. The synergistic activity between the natural compound β-thujaplicin and tigecycline in vitro was determined by the checkerboard broth microdilution assay and time-dependent killing curve. The mechanism underlining the synergistic effect between β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli was investigated by determining cell membrane permeability, bacterial intracellular reactive oxygen species (ROS) content, iron content, and tigecycline content. β-thujaplicin exhibited potentiation effect on tigecycline against tet(X4)-positive E. coli in vitro, and presented no significant hemolysis and cytotoxicity within the range of antibacterial concentrations. Mechanistic studies demonstrated that β-thujaplicin significantly increased the permeability of bacterial cell membranes, chelated bacterial intracellular iron, disrupted the iron homeostasis and significantly increased intracellular ROS level. The synergistic effect of β-thujaplicin and tigecycline was identified to be related to interfere with bacterial iron metabolism and facilitate bacterial cell membrane permeability. Our studies provided theoretical and practical data for the application of combined β-thujaplicin with tigecycline in the treatment of tet(X4)-positive E. coli infection.

The properties of ZnO nanofilms on titanium surface by atomic layer deposition / 口腔医学

Objective@#To compare and investigate the physicochemical characteristics and antibacterial effect of ZnO nanofilms prepared by atomic layer deposition(ALD) at different deposition cycles.@*Methods@#According to different ALD cycles, four groups were set up (control group, 300, 600 and 1 200 cycles group). Using DEZn and water as precursors, ZnO nanofilms were prepared by ALD on the surface of pure titanium specimens. Surface morphology of the films was observed by scanning electron microscope (SEM); the element composition and crystal type of the films were observed by energy dispersive spectrometer (EDS) and X-Ray Diffraction (XRD); the hydrophilicity and thickness of the films were detected by water contact angle detector and ellipsometer. The cytotoxicity of the films was evaluated by CCK-8 assay. The antibacterial effect against S. aureus in vitro of the films was evaluated by optical density method.@*Results@#The surface morphology of the films was uniform and compact as shown through SEM. The grain size increased with the increase of the number of ALD cycles. EDS results showed that the films were mainly composed of Zn and O elements. XRD results confirmed that the composition of the films was ZnO. Results of water contact angle showed that the films were hydrophobic. The thickness of the films was nanoscale and there was a linear relationship between the thickness and ALD cycles. All experimental groups showed no cytotoxicity. The 1 200 cycles group showed the highest antibacterial rate of 65.9% and 52.3% at 24 and 48 hours respectively, which was the best among all experimental groups. @*Conclusion@#The ZnO nanofilms prepared by ALD at different cycles on pure titanium surface are uniform and compact. Thickness of the films increases with the increase of ALD cycles. The films have good biocompatibility and anti-S. aureus effect in vitro. The 1 200 cycles group has the best antibacterial effect.

Functional biomaterials for comprehensive periodontitis therapy

Periodontitis is an inflammatory disease caused by bacterial infection directly, and the dysregulation of host immune-inflammatory response finally destroys periodontal tissues. Current treatment strategies for periodontitis mainly involve mechanical scaling/root planing (SRP), surgical procedures, and systemic or localized delivery of antimicrobial agents. However, SRP or surgical treatment alone has unsatisfactory long-term effects and is easy to relapse. In addition, the existing drugs for local periodontal therapy do not stay in the periodontal pocket long enough and have difficulties in maintaining a steady, effective concentration to obtain a therapeutic effect, and continuous administration always causes drug resistance. Many recent studies have shown that adding bio-functional materials and drug delivery systems upregulates the therapeutic effectiveness of periodontitis. This review focuses on the role of biomaterials in periodontitis treatment and presents an overview of antibacterial therapy, host modulatory therapy, periodontal regeneration, and multifunctional regulation of periodontitis therapy. Biomaterials provide advanced approaches for periodontal therapy, and it is foreseeable that further understanding and applications of biomaterials will promote the development of periodontal therapy.

Spectral analysis and Antibacterial activity of the bioactive principles of Sargassum tenerrimum J. Agardh collected from the Red sea, Jazan, Kingdom of Saudi Arabia / Análise espectral e atividade antibacteriana dos princípios bioativos de Sargassum tenerrimum J. Agardh coletados no mar Vermelho, Jazan, Reino da Arábia Saudita

Seaweeds are a major marine resource that can be explored to develop novel pharmaceutical molecules. The present study showed the presence of unique bioactive components in the petroleum ether extract (PEE) and methanolic extract (ME) of Sargassum tenerrimum. The gas chromatography-mass spectrometry analysis suggested that the PEE of S. tenerrimum contained antibacterial biomolecules: hexadecanoic acid, methyl ester, 17-pentatriacontene, dasycarpidan-1-methanol, and acetate (ester). However, the ME of S. tenerrimum exhibited better antibacterial effect than the PEE due to the presence of the bioactive compounds 1,2-benzenedicarboxylic acid, diisooctyl ester, tetratetracontane, 1-docosene, 1,2-benzenediol, and benzoic acid. Thus, promising antibacterial molecules can be isolated from S. tenerrimum for better therapeutic use.

As algas marinhas são um importante recurso marinho que pode ser explorado para desenvolver novas moléculas farmacêuticas. O presente estudo mostrou a presença de componentes bioativos únicos no extrato etéreo de petróleo (PEE) e no extrato metanólico (ME) de Sargassum tenerrimum. A análise por cromatografia gasosa espectrometria de massa sugeriu que o PEE de S. tenerrimum continha biomoléculas antibacterianas: ácido hexadecanoico, éster metílico, 17-pentatriaconteno, dasycarpidan-1-metanol e acetato (éster). Entretanto, o ME de S. tenerrimum exibiu melhor efeito antibacteriano do que o PEE devido à presença dos compostos bioativos ácido 1,2-benzenodicarboxílico, éster diisooctil, tetratetracontano, 1-docosene, 1,2-benzoenodiol e ácido benzoico. Assim, moléculas antibacterianas promissoras podem ser isoladas de S. tenerrimum para melhor uso terapêutico.

Spectral analysis and Antibacterial activity of the bioactive principles of Sargassum tenerrimum J. Agardh collected from the Red sea, Jazan, Kingdom of Saudi Arabia

Abstract Seaweeds are a major marine resource that can be explored to develop novel pharmaceutical molecules. The present study showed the presence of unique bioactive components in the petroleum ether extract (PEE) and methanolic extract (ME) of Sargassum tenerrimum. The gas chromatography-mass spectrometry analysis suggested that the PEE of S. tenerrimum contained antibacterial biomolecules: hexadecanoic acid, methyl ester, 17-pentatriacontene, dasycarpidan-1-methanol, and acetate (ester). However, the ME of S. tenerrimum exhibited better antibacterial effect than the PEE due to the presence of the bioactive compounds 1,2-benzenedicarboxylic acid, diisooctyl ester, tetratetracontane, 1-docosene, 1,2-benzenediol, and benzoic acid. Thus, promising antibacterial molecules can be isolated from S. tenerrimum for better therapeutic use.

Resumo As algas marinhas são um importante recurso marinho que pode ser explorado para desenvolver novas moléculas farmacêuticas. O presente estudo mostrou a presença de componentes bioativos únicos no extrato etéreo de petróleo (PEE) e no extrato metanólico (ME) de Sargassum tenerrimum. A análise por cromatografia gasosa-espectrometria de massa sugeriu que o PEE de S. tenerrimum continha biomoléculas antibacterianas: ácido hexadecanoico, éster metílico, 17-pentatriaconteno, dasycarpidan-1-metanol e acetato (éster). Entretanto, o ME de S. tenerrimum exibiu melhor efeito antibacteriano do que o PEE devido à presença dos compostos bioativos ácido 1,2-benzenodicarboxílico, éster diisooctil, tetratetracontano, 1-docosene, 1,2-benzoenodiol e ácido benzoico. Assim, moléculas antibacterianas promissoras podem ser isoladas de S. tenerrimum para melhor uso terapêutico.

Spectral analysis and Antibacterial activity of the bioactive principles of Sargassum tenerrimum J. Agardh collected from the Red sea, Jazan, Kingdom of Saudi Arabia / Análise espectral e atividade antibacteriana dos princípios bioativos de Sargassum tenerrimum J. Agardh coletados no mar Vermelho, Jazan, Reino da Arábia Saudita

Abstract Seaweeds are a major marine resource that can be explored to develop novel pharmaceutical molecules. The present study showed the presence of unique bioactive components in the petroleum ether extract (PEE) and methanolic extract (ME) of Sargassum tenerrimum. The gas chromatography-mass spectrometry analysis suggested that the PEE of S. tenerrimum contained antibacterial biomolecules: hexadecanoic acid, methyl ester, 17-pentatriacontene, dasycarpidan-1-methanol, and acetate (ester). However, the ME of S. tenerrimum exhibited better antibacterial effect than the PEE due to the presence of the bioactive compounds 1,2-benzenedicarboxylic acid, diisooctyl ester, tetratetracontane, 1-docosene, 1,2-benzenediol, and benzoic acid. Thus, promising antibacterial molecules can be isolated from S. tenerrimum for better therapeutic use.

Resumo As algas marinhas são um importante recurso marinho que pode ser explorado para desenvolver novas moléculas farmacêuticas. O presente estudo mostrou a presença de componentes bioativos únicos no extrato etéreo de petróleo (PEE) e no extrato metanólico (ME) de Sargassum tenerrimum. A análise por cromatografia gasosa-espectrometria de massa sugeriu que o PEE de S. tenerrimum continha biomoléculas antibacterianas: ácido hexadecanoico, éster metílico, 17-pentatriaconteno, dasycarpidan-1-metanol e acetato (éster). Entretanto, o ME de S. tenerrimum exibiu melhor efeito antibacteriano do que o PEE devido à presença dos compostos bioativos ácido 1,2-benzenodicarboxílico, éster diisooctil, tetratetracontano, 1-docosene, 1,2-benzoenodiol e ácido benzoico. Assim, moléculas antibacterianas promissoras podem ser isoladas de S. tenerrimum para melhor uso terapêutico.

Antibacterial and antifungal capacity of three commercially available mouthwashes with different concentrations of chlorhexidine / Efecto antibacteriano y antifúngico de tres enjuagues bucales comerciales con diferentes concentraciones de clorhexidina

Abstract Chlorhexidine was introduced almost seven decades ago and has a myriad of applications in dentistry. Few studies have evaluated the antimicrobial and antifungal capacity of different concentrations of chlorhexidine mouthwashes. Therefore, the aim of this study, was to evaluate in vitro, the antibacterial and antifungal capacity of three commercially available mouthwashes in Costa Rica, with different concentrations of chlorhexidine, 0.12%, 0.06%, and 0.03%. The experimental method selected was the Kirby-Bauer method to evaluate the antibacterial and antifungal effect of each compound by measuring the inhibitory effect on Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Candida albicans strains, exposed to the antiseptic solutions. All samples showed some degree of antibacterial and antifungal effect. Even though we provide in vitro results, our findings are of relevance since all the species used in our experiment are microorganisms that may be present in dental plaque. Our results further support evidence that oral hygiene regimens may include mouthwashes with low doses of chlorhexidine and maintain reasonable antibacterial and antifungal efficacy.

Resumen La clorhexidina se introdujo hace casi siete décadas y tiene una gran variedad de aplicaciones en odontología. Pocos estudios han evaluado la capacidad antimicrobiana y antifúngica de diferentes concentraciones de enjuagues bucales con clorhexidina. Por lo tanto, el objetivo de este estudio fue evaluar in vitro, la capacidad antibacteriana y antifúngica de tres enjuagues bucales disponibles comercialmente en Costa Rica, con diferentes concentraciones de clorhexidina, 0.12%, 0.06% y 0.03%. El método experimental seleccionado fue el método Kirby-Bauer para evaluar el efecto antibacteriano y antifúngico de cada compuesto midiendo el efecto inhibidor sobre Staphylococcus aureus, Enterococcus faecalis, Escherichia coli y Candida albicans, expuestos a la solución antiséptica. Todas las muestras mostraron algún grado de efecto antibacteriano y antifúngico. Aunque proporcionamos resultados in vitro, nuestros hallazgos son de relevancia, ya que todas las especies utilizadas en nuestro experimento son microorganismos que pueden estar presentes en la placa dental. Nuestros resultados respaldan aún más la evidencia de que los regímenes de higiene bucal pueden incluir enjuagues bucales con dosis bajas de clorhexidina y mantener una eficacia antibacteriana y antifúngica razonable.

Study on the substance basis of "property-taste-efficacy" of Liquorice and Rhizoma chinensis based on supramolecular system induced by weak bond / 药学学报

It is a common understanding that turbidity and precipitation of traditional Chinese medicine are easy to occur in the process of decocting. At present, our research group found that the cause of "multi-phase of traditional Chinese medicine decoction" mainly came from the interaction between the effective components of traditional Chinese medicine, especially the interaction of acid and base components. For example, the Liquorice and Rhizoma chinensis was a supramolecular system formed by a large number of active components in the decoction (>30%), and could stably exist in the decoction system. In this study, the supramolecular part was extracted, and the morphology of the supramolecular part was characterized by scanning electron microscopy and dynamic light scattering. It was observed that the supramolecular particles were uniform in size and regular in shape. The main components of supramolecular sites were identified by liquid mass spectrometry (LC-MSn). The results of UV and IR spectra showed that the chemical components of Liquorice and Rhizoma chinensis in the co-decocting process collided with each other, and weak bonds were formed between the functional groups of the molecules, which then induced the aggregation to form supramolecules. Thereafter, Through the diarrhea model of mice, sensory evaluation and antibacterial activity evaluation found that Liquorice and Rhizoma chinensis decocted together enhanced the antibacterial activity of Rhizoma, and compatibility "reconcile" Rhizoma "big bitter cold" property compared with single decoction group and interval administration group. All animal experiments were approved by the Animal Ethics Committee of Beijing University of Chinese Medicine, and the relevant regulations of Beijing University of Chinese Medicine on experimental animals were strictly followed. In this study, supramolecular chemistry method was used to preliminarily discuss the scientific connotation of "increasing efficiency and decreasing toxicity" of Liquorice and Rhizoma chinensis combined decoction from three perspectives of "property, efficacy and taste", and provide new ideas for the basic research of "reconcile" compatibility of Liquorice.

Molecular interactions between the main components of Shuanghuanglian injection and ciprofloxacin injection based on self-assembly / 药学学报

The combination of Shuanghuanglian injection (SHLI) and ciprofloxacin injection (CIPI) is frequently prescribed in clinical practice, but the basis for the combination is weak. In this study, isothermal titration calorimetry and ultraviolet-visible absorption spectrometry were applied to identify the molecular interactions of SHLI and its main components, chlorogenic acid and neochlorogenic acid with CIPI. Scanning electron microscopy, Fourier-transform infrared spectroscopy, and cold-spray ionization mass spectrometry were performed to confirm that this molecular interaction was related to the formation of self-assembled supramolecular systems induced by chlorogenic acid and neochlorogenic acid with CIPI through weak intermolecular bonds. The antibacterial activity toward Pseudomonas aeruginosa (P. aeruginosa) was evaluated via molecular interactions, and the inhibitory ability of SHLI, chlorogenic acid and neochlorogenic acid against P. aeruginosa was significantly reduced after interaction with CIPI. A molecular docking study demonstrated that the reduced antibacterial ability was closely related to the competitive binding of drug molecules to the same binding site of the DNA gyrase B (GyrB) subunit of P. aeruginosa. The present study uncovered the intermolecular interactions of SHLI and its main components chlorogenic acid and neochlorogenic acid with CIPI from the perspective of molecular self-assembly and contribute to the reduction of its antibacterial ability, providing a basis for the clinical combination of SHLI and CIPI.

Cytotoxicity and antibacterial activity of bleached turmeric hydro-alcoholic extract versus sodium hypochlorite as an endodontic irrigant: in vitro study / Citotoxicidade e atividade antibacteriana do extrato hidroalcoólico de cúrcuma branqueado versus hipoclorito de sódio como irrigante endodôntico: estudo in vitro

Objetivo: Avaliar a citotoxicidade e o efeito antibacteriano do extrato hidroalcoólico de cúrcuma branqueado comparado ao hipoclorito de sódio como irrigante endodôntico. Material e Métodos: A citotoxicidade foi avaliada em fibroblastos de pele humana usando o ensaio MTT. Os irrigantes foram testados em intervalos de tempo de 1, 5 e 15 minutos. Após o tempo de contato, a solução de MTT foi adicionada e as placas de poços foram incubadas. Após o período de incubação, a densidade óptica foi lida e correlacionada com a porcentagem de viabilidade celular. A eficiência antibacteriana foi avaliada usando o teste de contato direto. Cada irrigante endodôntico foi adicionado à suspensão fresca de Enterococcus faecalis e ao meio de infusão cérebro-coração e então incubados por 48 horas. Após o período de incubação, as leituras de densidade óptica foram obtidas e lidas por leitor de ELISA a 620 nm. Resultados: Os resultados do teste de citotoxicidade revelaram que o extrato de cúrcuma branqueado apresentou porcentagem de viabilidade celular significativamente maior do que o hipoclorito de sódio (NaOCl) em todos os intervalos de tempo (p<0,001). No entanto, no grupo de intervenção, a porcentagem de viabilidade celular diminuiu significativamente ao longo do tempo. Os resultados do teste antibacteriano mostraram inibição bacteriana por ambos os grupos com diferença não significativa entre os dois grupos testados (p<0,05). Conclusão:O extrato hidroalcoólico de cúrcuma branqueado pode representar uma alternativa fitoterápica irrigante endodôntico para evitar os efeitos tóxicos indesejáveis do NaOCl devido à sua menor citotoxicidade e efeito antibacteriano proeminente contra Enterococcus faecalis (AU)

Objective: To evaluate the cytotoxicity and antibacterial effect of bleached turmeric hydro-alcoholic extract compared to sodium hypochlorite as an endodontic irrigant. Material and Methods: Cytotoxicity was evaluated on human skin fibroblasts using MTT assay. The irrigants were tested at 1, 5- and 15-minutes time intervals. After contact time, MTT solution was added and well plates were incubated. After the incubation period, optical density was read and correlated with cell viability percent. Antibacterial efficiency was evaluated using direct contact test. Each endodontic irrigant was added to fresh Enterococcus faecalis suspension and brain heart infusion media then incubated for 48 hours. After incubation period, optical density readings were obtained and read by ELISA reader at 620 nm. Results:Results of cytotoxicity test revealed that bleached turmeric extract had significant higher cell viability percent than Sodium hypochlorite (NaOCl) at all time intervals (p<0.001). However, in the intervention group, cell viability percent significantly decreased over time. Results of antibacterial test showed bacterial inhibition by both groups with non-significant difference between the two tested groups (p<0.05). Conclusion: Bleached turmeric hydro-alcoholic extract can represent an herbal alternative endodontic irrigant to avoid the undesirable toxic effects of NaOCl due to its less cytotoxicity and prominent antibacterial effect against Enterococcus faecalis. (AU)

Preparation and in vitro evaluation of Vancomycin loaded Montmorillonite-Sodium Alginate topical gel for wound infection

Abstract Despite decades of research, wound healing remains a significant public health problem. This study aimed to develop and evaluate a topical sodium alginate gel containing vancomycin (Van) loaded MMT NPs for wound healing applications. Van was loaded in MMT at different conditions (pHs of 6, 7 and temperatures of 40, 50 °C) (Van/MMT NPs). The optimum formulation (with the smallest particle size and a high value of zeta potential; 270.8 ± 77.35 nm and -35.96 ± 2.73, respectively) showed a high drug-loading capacity (entrapment efficacy of 96%) and a sustained release pattern of Van (95%) over 480 min. The optimum Van/MMT NPs were embedded into the sodium alginate (SA) gel (Van/MMT NPs/SA gel). The Van/ MMT NPs/SA gel showed a sustained and slow release pattern of Van (95%) over 50 h. FTIR tests revealed the electrostatic interaction between MMT and Van. The broth macrodilution tube method was used to determine the minimum inhibitory concentration (MIC) of Van, Van/ MMT NPs, and Van/MMT NPs/SA gel against Staphylococcus aureus. The results showed the promising antibacterial activity of Van/MMT NPs/SA gel, thus, this gel can be a promising formulation for the management of infected wounds

Based on weak bond chemistry, the interaction mechanism between glycyrrhiza protein and berberine in water decocting process of Rhizoma Coptidis and Liquorice was investigated / 药学学报

The purpose of this study was to explore the interaction mechanism between glycyrrhiza protein and berberine in the decocting process of Rhizoma Coptidis and Liquorice and its effect on the pharmacodynamic effect. In this experiment, licorice crude protein was obtained from licorice decoction pieces, and it was found that licorice crude protein and berberine could form spherical supramolecular particles after decocting together. Morphological characterization was carried out by using Malvin particle size analyzer and emission scanning electron microscopy, and the supramolecular particles were observed to be nanoscale, which was significantly different from the morphology of licorice protein and berberine. The results of ultraviolet, infrared and fluorescence spectroscopy showed that the mechanism of molecular interaction was induced by weak bonds such as electrostatic attraction and hydrophobic interaction. Furthermore, the antimicrobial activity of berberine was significantly affected by the supramolecular particles of licorice protein-berberine, which were significantly different from the mechanical mixture. This study reveals the pharmacological value of macromolecular substances such as proteins in the decoction of licorice and Coptis chinensis from a new perspective, which is helpful to promote the secondary development of clinical effective prescriptions, especially the research on the pharmacological substance basis of classic famous prescriptions.

Antibacterial activity and mechanism of moxifloxacin nanoparticles against drug-resistant Pseudomonas aeruginosa / 药学学报

We prepared moxifloxacin (MXF) loaded nanoparticles by nano-precipitation/self-assembly method, then compared the antibacterial activity of MXF and MXF loaded nanoparticles, and investigated the antibacterial mechanism of MXF loaded nanoparticles against Pseudomonas aeruginosa in vitro. The physicochemical properties such as particle size and zeta potential were investigated by laser particle size analyzer. The in vitro release characteristics were investigated by high performance liquid chromatography (HPLC). The effect of nanoparticles on HBE cells viability was investigated by CCK-8 assay. In addition, the in vitro antibacterial activity was investigated by minimum inhibitory concentration (MIC) assay, biofilm formation assays and transmission electron microscope (TEM) observation, then the antibacterial mechanism was initially explored. The particle size measurement showed that the nanoparticles had a size of 332.5 ± 2.7 nm, a polymer dispersion index (PDI) of 0.125 ± 0.053, a zeta potential of -24.3 ± 1.7 mV, and a uniform particle size distribution, drug loading content was (6.02 ± 1.27) %, encapsulation efficiency was (16.69 ± 1.17) %. The TEM results show that the nanoparticles have a spheroidal structure, and the particle size and distribution are consistent with the particle size measurement results. The nanoparticles can be effectively and rapidly released in phosphate buffer saline (PBS), releasing about 70% in 24 h, and releasing 87% in 72 h, and almost completely releasing the MXF at 120 h. At the same time, compared with moxifloxacin free drug, its MIC value is 8 μg·mL-1, which is 1/2 of MXF solution, and can significantly inhibit the formation of bacterial biofilms. It has well antibacterial activity in vitro and can be targeted to the surface of bacteria to exert its efficacy and improve the antibacterial effect. The moxifloxacin nanoparticles prepared in this study has a uniform particle size distribution, well drug release performance and antibacterial effect, and provides new ideas and strategies for the treatment of bacterial lung infection and the development of new antibacterial nanoformulations.

Antioxidant Potential of Four Species of Natural Product and Therapeutic Strategies for Cancer through Suppression of Viability in the Human Multiple Myeloma Cell Line U266 / 生物医学与环境科学（英文）

OBJECTIVE@#This research aimed to evaluate the protective effects of bioactive compounds such as phenolic acids, flavonoids, and tannins present in four species extracted with methanol.@*METHODS@#The total phenolic content of the methanolic extracts was measured spectrophotometrically. The effect of the extracts on cell viability in U266 cells was measured. The effects of extracts on free radical scavenging were assessed by the DPPH test and FRAP assay. Antibacterial effects of the natural products in this report were investigated by using the disc diffusion method.@*RESULTS@#Our results clearly demonstrated that the methanolic extracts were characterized by a high amount of phenolic compounds. It has been speculated that ME-TA and ME-TAl exhibit a significant (P < 0.05) and dose-dependent antiradical potential. The exposure of cells to high doses of extracts almost completely suppressed cell growth in vitro. ME-TA and ME-TAl showed significant cytotoxic effects at a concentration of 100 μg/mL in the U266 cell line. ME-TAl and ME-CF inhibited the growth of B. subtilis and S. aureus, respectively, to the same extent as 10 μg/μL of chloramphenicol at a concentration of 1 mg/mL.@*CONCLUSION@#Overall, these results suggest that plants used in traditional medicine have a novel application as free radical scavengers, bacterial inhibitors and tumor suppressors.

Study on Antimicrobial Activity of Ampelopsin Combined with 8 Kinds of Antibiotic against Pseudomonas aeruginosa in vitro / 中国药房

OBJECTIVE： To study the antimicrobial activity of ampelopsin combined with 8 kinds of antibiotic against Pseudomonas aeruginosa （PA） in vitro. METHODS： Chessboard trace dilution method was used to determine minimum inhibitory concentration （MIC） of ampelopsin combined with ceftriaxone， cefoperazone/sulbactam， piperacillin/tazobactam， cefoperazone， ciprofloxacin， amikacin， piperacillin and cefepime to PA strain ATCC27853 and 7 isolated strains PA135， PA216， PA276， PA281， PA291， PA314 and PA319. Fractional inhibitory concentration index （FICI） was used to evaluate its effects of drug combination. Clinically isolated strain PA319 were taken as target strain and then divided into normal control group， ampelopsin alone group， antibiotics alone group and ampelopsin+antibiotic combination group. Using MIC of ampelopsin and antibiotics during drug combination as active concentration， the number of colonies cultured for 0， 4， 8， 12 and 24 h was counted， and the time-sterilization curve was drawn. RESULTS： For above 8 kinds of strains， MIC of ampelopsin alone was 128-256 mg/L； FICI of ampelopsin combined with ceftriaxone， cefoperazone/sulbactam， piperacillin/tazobactam， cefoperazone， ciprofloxacin， amikacin， piperacillin and cefepime to 8， 8， 7， 6， 4， 4， 6 and 6 strains were equal to or lower than 1， respectively. In time-antibacterial curve， compared with antibiotics alone， the number of colonies decreased by 2.65， 2.30， 0.42， 0.47， 0.53， 1.19， 1.74， 1.04 lgCFU/mL respectively after ampelopsin combined with ceftriaxone， cefperazone/sulbactam， piperacillin/tazobactam， cefoperazone， ciprofloxacin， amikacin， piperacillin and cefepime. CONCLUSIONS： Ampelopsin combined with ceftriaxone and cefoperazone/sulbactam show better antibacterial effect on PA.

Antibacterial spectrum of silibinin and isomers and its antibacterial effect with antibiotics / 中草药

Objective To investigate the in vitro antibacterial spectrum of silibinin and its isomers and the combined antibacterial effect of silibinin and commonly-used clinical antibiotics. Methods Micro-broth dilution method was used to determine the minimum inhibitory concentration (MIC) of silibinin and its isomers against six standard strains and six clinical isolates (74 strains) of common bacteria infections. Plate count method was used to measure the growth inhibition curves of different concentrations of silibinin against six standard strains. Checkerboard micro-broth dilution method was used to carry out the combined susceptibility test of silibinin and clinical antibiotics. The fractional inhibitory concentration (FIC) was calculated to determine the combined antibacterial effect of silibinin and antibiotics. Results The MICs of silibinin against standard strains of Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, and Enterococcus faecium were between 50 μg/mL and 400 μg/mL, and those of silibinin for standard strains of Escherichia coli and Pseudomonas aeruginosa were both greater than 400 μg/mL. The MICs of silibinin for clinical strains, Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, and Enterococcus faecium were all within the range of 100 μg/mL to 400 μg/mL, and MICs of silibinin against clinical strains of Escherichia coli and Pseudomonas aeruginosa were greater than 400 μg/mL. The MICs of other isomers of silibinin against six standard strains were greater than or equal to 400 μg/mL. Silibinin had a significant inhibitory effect on the growth curve of standard strains of Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, and Enterococcus faecium, which increased with increasing drug concentration, and it had no effect on that of Escherichia coli and Pseudomonas aeruginosa. The FIC of silibinin combined with penicillin/erythromycin for gram-positive test bacteria was in the range of 0.5 2 or 1 < FIC ≤ 2. Conclusion Silibinin has a notable antibacterial activity to gram-positive bacteria with the best inhibitory effect on Staphylococcus epidermidis. The antibacterial activities of silibinin is higher than those of other isomers. The combined antibacterial effect of silibinin and penicillin/erythromycin is mainly additive and irrelevant, while that of silibinin and ciprofloxacin or gentamicin is mainly antagonistic or irrelevant.