Histological assessment, anti-quorum sensing, and anti-biofilm activities of Dioon spinulosum extract: in vitro and in vivo approach

Beyond antibiotics: Emerging antivirulence strategies to combat Pseudomonas aeruginosa in cystic fibrosis

Pseudomonas aeruginosa is an opportunistic pathogen that poses a significant threat to individuals suffering from cystic fibrosis (CF). The pathogen is highly prevalent in CF individuals and is responsible for chronic infection, resulting in severe tissue damage and poor patient outcome. Prolonged antibiotic administration has led to the emergence of multidrug resistance in P. aeruginosa. In this direction, antivirulence strategies achieving targeted inhibition of bacterial virulence pathways, including quorum sensing, efflux pumps, lectins, and iron chelators, have been explored against CF isolates of P. aeruginosa. Hence, this review article presents a bird's eye view on the pulmonary infections involving P. aeruginosa in CF patients by laying emphasis on factors contributing to bacterial colonization, persistence, and disease progression along with the current line of therapeutics against P. aeruginosa in CF. We further collate scientific literature and discusses various antivirulence strategies that have been tested against P. aeruginosa isolates from CF patients.

Quorum quenching mediated biofilm impediment in Chromobacterium violaceum and Staphylococcus aureus by leaf extracts of Delonix elata

Biofilms are complex communities of microorganisms that cause systemic infections, resistance development and delay in healing wounds. Biofilms can form in various parts of the human body, such as the teeth, lungs, urinary tract, and wounds. Biofilm complicates the effects of antibiotics in treating infections. In search of a cure, a plant-based phyto component was selected for this investigation as an anti-quorum-mediated biofilm restricting agent in Gram-negative Chromobacterium violaceum and Gram-positive Staphylococcus aureus. The bioactive components in Delonix elata (DE) ethyl acetate extract were identified using Gas chromatography and mass spectrometry. The extract was examined for toxicity using 3T3 cell lines and brine shrimp and ascertained to be non-toxic. Violacein was inhibited up to 68.81 % in C. violaceum at 0.6 mg/ml concentration. Hemolysin synthesis impediments in C. violaceum and S. aureus were 80 % and 51.35 %, respectively, at 0.6 mg/ml of DE extract. At 0.6 mg/ml, EPS was abated by up to 49 % in C. violaceum and 35.26 % in S. aureus. DE extract prevented biofilm formation in C. violaceum and S. aureus up to 76.45 % and 58.15 %, respectively, while associated eDNA was suppressed up to 67.50 % and 53.47 % at the respective sub-MIC concentrations. Expression of genes such as cviI, cviR, vioA, vioB, and vioE were dramatically reduced in C. violaceum, while genes such as agrA, sarA, fnbA, and fnbB were significantly reduced in S. aureus. Docking demonstrates that two or more DE molecules bind efficiently to the QS receptors of C. violaceum and S. aureus. Thus, DE extract can be investigated for therapeutic purposes against pathogenic microorganisms by rendering them less virulent through quorum quenching mediated action.

Dioon rzedowskii: An antioxidant, antibacterial and anticancer plant extract with multi-faceted effects on cell growth and molecular signaling

This study investigated the antioxidant, anticancer, antibacterial properties of Dioon rzedowskii extract, which had not been previously explored. We aimed to determine the extract's effect on liver and breast cancer cell lines and on solid Ehrlich carcinoma (SEC) mouse model to investigate the underlying molecular mechanisms. Three female albino mice groups were established: a tumor control group, a group treated with 100 mg/kg of the extract (D100), and a group treated with 200 mg/kg of the extract (D200) for 16 days after tumor development. Results showed that the D. rzedowskii extract inhibited cell growth in both MCF-7 and HepG2 cells in a concentration-dependent manner. This was achieved by suppressing the cell proliferation and inducing apoptosis. The extract also improved liver, heart, and kidney functions compared to the tumor control. Furthermore, oral administration of the extract reduced tumor volume and alleviated oxidative stress in tumor tissue. The anticancer effects were associated with overexpression of p53 and Bax and downregulation of cyclin D1 expression, which was attributed to decreased phosphorylated MAPK kinases. Additionally, D. rzedowskii exhibited antibacterial activity against K. pneumoniae isolated from cancer patients. The extract inhibited bacterial growth and reduced the membrane integrity. The study suggests that D. rzedowskii has promising potential as an adjunctive therapy for cancer treatment. Further investigations are needed to explore its combined anticancer efficacy. These results emphasize the value of natural products in developing compounds with potential anticancer activity and support a paradigm shift in cancer management to improve patients' quality of life.

Investigation of bioactive components responsible for the antibacterial and anti-biofilm activities of Caroxylon volkensii by LC-QTOF-MS/MS analysis and molecular docking

Caroxylon volkensii is a wild desert plant of the family Amaranthaceae. This study represents the first report of the metabolomic profiling of C. volkensii by liquid chromatography quadrupole-time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS). The dereplication study of its secondary metabolites led to the characterization of 66 known compounds. These compounds include catecholamines, tyramine derivatives, phenolic acids, triterpenoids, flavonoids, and others. A new tyramine derivative, alongside other known compounds, was reported for the first time in the Amaranthaceae family. The new derivative and the first-reported compounds were putatively identified through MS/MS fragmentation data. Given the notorious taxonomical challenges within the genus Salsola, to which C. volkensii previously belonged, our study could offer a valuable insight into its chemical fingerprint and phylogenetic relationship to different Salsola species. The antibacterial potential of C. volkensii methanolic extract (CVM) against Pseudomonas aeruginosa was screened. The minimum inhibitory concentration (MIC) of CVM ranged from 32 to 256 μg mL-1. The anti-quorum sensing potential of CVM resulted in a decrease in the percentage of strong and moderate biofilm-forming isolates from 47.83% to 17.39%. It revealed a concentration-dependent inhibitory activity on violacein formation by Chromobacterium violaceum. Moreover, CVM exhibited an in vivo protective potential against the killing capacity of P. aeruginosa isolates. A molecular docking study revealed that the quorum-sensing inhibitory effect of CVM can be attributed to the binding of tyramine conjugates, ethyl-p-digallate, and isorhamnetin to the transcriptional global activator LasR.

Evaluation of Tamarix nilotica Fractions in Combating Candida albicans Infections

OBJECTIVES

Evaluation of the antifungal properties of Tamarix nilotica fractions against Candida albicans clinical isolates.

METHODS

The in vitro antifungal potential was evaluated by agar well diffusion and broth microdilution methods. The antibiofilm potential was assessed by crystal violet, scanning electron microscopy (SEM), and qRT-PCR. The in vivo antifungal activity was evaluated by determining the burden in the lung tissues of infected mice, histopathological, immunohistochemical studies, and ELISA.

RESULTS

Both the dichloromethane (DCM) and ethyl acetate (EtOAc) fractions had minimum inhibitory concentration (MIC) values of 64-256 and 128-1024 μg/mL, respectively. SEM examination showed that the DCM fraction decreased the biofilm formation capacity of the treated isolates. A significant decline in biofilm gene expression was observed in 33.33% of the DCM-treated isolates. A considerable decline in the CFU/g lung count in infected mice was observed, and histopathological examinations revealed that the DCM fraction maintained the lung tissue architecture. Immunohistochemical investigations indicated that the DCM fraction significantly (p < 0.05) decreased the expression of pro-inflammatory and inflammatory cytokines (TNF-α, NF-kB, COX-2, IL-6, and IL-1β) in the immunostained lung sections. The phytochemical profiling of DCM and EtOAc fractions was performed using Liquid chromatography-mass spectrometry (LC-ESI-MS/MS).

CONCLUSION

T. nilotica DCM fraction could be a significant source of natural products with antifungal activity against C. albicans infections.

New Antimicrobial Strategies to Treat Multi-Drug Resistant Infections Caused by Gram-Negatives in Cystic Fibrosis

People with cystic fibrosis (CF) suffer from recurrent bacterial infections which induce inflammation, lung tissue damage and failure of the respiratory system. Prolonged exposure to combinatorial antibiotic therapies triggers the appearance of multi-drug resistant (MDR) bacteria. The development of alternative antimicrobial strategies may provide a way to mitigate antimicrobial resistance. Here we discuss different alternative approaches to the use of classic antibiotics: anti-virulence and anti-biofilm compounds which exert a low selective pressure; phage therapies that represent an alternative strategy with a high therapeutic potential; new methods helping antibiotics activity such as adjuvants; and antimicrobial peptides and nanoparticle formulations. Their mechanisms and in vitro and in vivo efficacy are described, in order to figure out a complete landscape of new alternative approaches to fight MDR Gram-negative CF pathogens.

Phytochemical investigation, antibacterial, and ameliorative potential effects of Tamarix nilotica on LPS-induced acute lung injury model in mice

Acute lung injury (ALI) is a serious illness with a high mortality rate of 40-60%. It is characterised by systemic inflammatory processes and oxidative stress. Gram-negative bacterial infections are the major cause of ALI, and lipopolysaccharide (LPS) is the major stimulus for the release of inflammatory mediators. Hence, there is an urgent need to develop new therapies which ameliorate ALI and prevent its serious consequences. The Middle Eastern native plant Tamarix nilotica (Ehrenb) Bunge belongs to the family Tamaricaceae, which exhibits strong anti-inflammatory and antioxidant effects. Thus, the current work aimed to ensure the plausible beneficial effects of T. nilotica different fractions on LPS-induced acute lung injury after elucidating their phytochemical constituents using LC/MS analysis. Mice were randomly allocated into six groups: Control saline, LPS group, and four groups treated with total extract, DCM, EtOAc and n-butanol fractions, respectively, intraperitoneal at 100 mg/kg doses 30 min before LPS injection. The lung expression of iNOS, TGF-β1, NOX-1, NOX-4 and GPX-1 levels were evaluated. Also, oxidative stress was assessed via measurements of MDA, SOD and Catalase activity, and histopathological and immunohistochemical investigation of TNF-α in lung tissues were performed. T. nilotica n-butanol fraction caused a significant downregulation in iNOS, TGF-β1, TNF-α, NOX-1, NOX-4, and MDA levels (p ˂ 0.05), and significantly elevated GPX-1 expression levels, SOD, and catalase activity (p ˂ 0.05), and alleviated all histopathological abnormalities confirming its advantageous role in ALI. The antibacterial activities of T. nilotica and its different fractions were investigated by agar well diffusion method and broth microdilution method. Interestingly, the n-butanol fraction exhibited the best antibacterial activity against Klebsiella pneumoniae clinical isolates. It also significantly reduced exopolysaccharide quantity, cell surface hydrophobicity, and biofilm formation.

Bacterial biofilm inhibitors: An overview

Bacteria that cause infectious diseases adopt biofilms as one of their most prevalent lifestyles. Biofilms enable bacteria to tolerate environmental stress and evade antibacterial agents. This bacterial defense mechanism has rendered the use of antibiotics ineffective for the treatment of infectious diseases. However, many highly drug-resistant microbes have rapidly emerged owing to such treatments. Different signaling mechanisms regulate bacterial biofilm formation, including cyclic dinucleotide (c-di-GMP), small non-coding RNAs, and quorum sensing (QS). A cell density-dependent phenomenon, QS is associated with c-di-GMP (a global messenger), which regulates gene expression related to adhesion, extracellular matrix production, the transition from the planktonic to biofilm stage, stability, pathogenicity, virulence, and acquisition of nutrients. The article aims to provide information on inhibiting biofilm formation and disintegrating mature/preformed biofilms. This treatment enables antimicrobials to target the free-living/exposed bacterial cells at lower concentrations than those needed to treat bacteria within the biofilm. Therefore, a complementary action of antibiofilm and antimicrobial agents can be a robust strategic approach to dealing with infectious diseases. Taken together, these molecules have broad implications for human health.

The potential beneficial role of Ginkgetin in doxorubicin-induced hepatotoxicity: Elucidating the underlying claim

Doxorubicin (DOX) is a widely used chemotherapeutic agent for various tumors treatment; apart from its chemotherapeutic activity, the traditional usage of DOX has been limited by its adverse effects on multiple organs, mainly hepatotoxicity. The molecular mechanisms underlying DOX hepatotoxicity are mainly due to the production of reactive oxygen species (ROS) inducing oxidative stress, diminishing antioxidant enzymes, apoptosis, inflammation, and mitochondrial dysfunction. Thus, there is an urgent need to develop a therapy that minimizes DOX hepatotoxicity and widens its use in various types of cancers without fear of its serious hepatotoxicity. Ginkgetin (GINK), a natural biflavonoid, exhibits diverse actions, including promising free radical scavenging, antioxidant, and anti-inflammatory activities. So, this study's objectives were to determine whether GINK could mitigate DOX's hepatotoxic effects and look into a putative hepatoprotective molecular pathway. Mice were divided into five groups: Normal control, control GINK 100, Untreated DOX group, and DOX groups treated with GINK (50 and 100 mg/kg) intraperitoneally daily for four days before DOX administration and an additional three days afterward. GINK 100 pretreatment showed marked protection from DOX hepatotoxicity and also attenuation of histopathological structural alterations. These outcomes were corroborated biochemically by a considerable decrease in alanine aminotransferases, aspartate aminotransferase, and alkaline phosphatase levels. GINK significantly augmented silent information regulator 1 and nuclear translocation of NF-E2-related factor 2 and repressed the expression and protein levels of forkhead box protein O1, inducible nitric oxide synthase, and P53 relative to DOX group. GINK alleviated oxidative stress and induced significant anti-inflammatory effects via suppression of interleukin-6, nuclear factor Kabba B, and iNOS respectively. This study is the first to investigate GINK's potentially beneficial effects in acute DOX hepatotoxicity, possibly exhibiting antioxidant, anti-inflammatory, and anti-apoptotic effects by modulation of Sirt1/FOXO-1/NF-κB Signal.

Maternal transfer of resorcinol-bis(diphenyl)-phosphate perturbs gut microbiota development and gut metabolism of offspring in rats

Resorcinol-bis(diphenyl)-phosphate (RDP), an emerging organophosphate flame retardant, is increasingly used as a primary alternative for decabromodiphenyl ether and is frequently detected in global environmental matrices. However, the long-term effects of its exposure to humans remain largely unknown. To investigate its intergenerational transfer capacity and health risks, female Sprague Dawley rats were orally exposed to RDP from the beginning of pregnancy to the end of the lactation period. The RDP content, gut microbiota homeostasis, and metabolic levels were determined. RDP accumulation occurred in the livers of maternal rats and offspring and increased with exposure time. 16S rRNA gene sequencing showed that exposure to RDP during pregnancy and/or lactation significantly disrupted gut microbiota homeostasis, as evidenced by decreased abundance and diversity. In particular, the abundance of Turicibacter, Adlercreutzia, and YRC22 decreased, correlating significantly with glycollipic metabolism. This finding was consistent with the reduced levels of short-chain fatty acids, the crucial gut microbial metabolites. Meanwhile, RDP exposure resulted in changes in gut microbiome-related metabolism. Nine critical overlapping KEGG metabolic pathways were identified, and the levels of related differential metabolites decreased. Our results suggest that the significant adverse impacts of RDP on gut microbiota homeostasis and metabolic function may increase the long-term risks related to inflammation, obesity, and metabolic diseases.

Recent advances in therapeutic targets identification and development of treatment strategies towards Pseudomonas aeruginosa infections

The opportunistic human pathogen Pseudomonas aeruginosa is the causal agent of a wide variety of infections. This non-fermentative Gram-negative bacillus can colonize zones where the skin barrier is weakened, such as wounds or burns. It also causes infections of the urinary tract, respiratory system or bloodstream. P. aeruginosa infections are common in hospitalized patients for which multidrug-resistant, respectively extensively drug-resistant isolates can be a strong contributor to a high rate of in-hospital mortality. Moreover, chronic respiratory system infections of cystic fibrosis patients are especially concerning, since very tedious to treat. P. aeruginosa exploits diverse cell-associated and secreted virulence factors, which play essential roles in its pathogenesis. Those factors encompass carbohydrate-binding proteins, quorum sensing that monitor the production of extracellular products, genes conferring extensive drug resistance, and a secretion system to deliver effectors to kill competitors or subvert host essential functions. In this article, we highlight recent advances in the understanding of P. aeruginosa pathogenicity and virulence as well as efforts for the identification of new drug targets and the development of new therapeutic strategies against P. aeruginosa infections. These recent advances provide innovative and promising strategies to circumvent infection caused by this important human pathogen.

Antibacterial and Antibiofilm Effects of Allelopathic Compounds Identified in Medicago sativa L. Seedling Exudate against Escherichia coli

In this study, the allelopathic properties of Medicago sativa L. (alfalfa) seedling exudates on the germination of seeds of various species were investigated. The compounds responsible for the allelopathic effects of alfalfa were identified and characterized by employing liquid chromatography ion mobility high-resolution mass spectrometry. Crude exudates inhibited the germination of seeds of all various plant species tested. Overall, nine compounds in alfalfa were identified and quantified. The most predominant compounds were a hyperoside representing a flavonoid glucoside, the non-proteinogenic amino acid canavanine, and two dipeptides, identified as H-Glu-Tyr-OH and H-Phe-Glu-OH. The latter corresponds to the first finding that dipeptides are exuded from alfalfa seedlings. In addition, the antibacterial and antibiofilm activities of alfalfa exudate and its identified compounds were elucidated. Both hyperoside and canavanine revealed the best antibacterial activity with minimum inhibitory concentration (MIC) values that ranged from 8 to 32 and 32 to 256 µg/mL, respectively. Regarding the antibiofilm action, hyperoside and canavanine caused a decline in the percentage of E. coli isolates that possessed a strong and moderate biofilm-forming potential from 68.42% to 21.05% and 31.58%, respectively. Studies on their inhibiting effects exhibit that these major substances are predominantly responsible for the allelopathic and antimicrobial effects of the crude exudates.

Exploring the potential efficacy of phage therapy for biocontrol of foodborne pathogenic extensively drug-resistant Escherichia coli in gastrointestinal tract of rat model

AIM

The emergence of extensively drug-resistant (XDR) Escherichia coli leaves little or no therapeutic options for the control of these foodborne pathogens. The goal is to isolate, characterize, and assess the potential efficacy of a bacteriophage in the treatment of an induced gastrointestinal tract infection.

MAIN METHODS

Sewage water was used to isolate phage phPE42. Transmission electron microscope was used for the visualization of phage morphology. Lysis profile, growth kinetics, and stability studies were determined. The ability of phage to eradicate biofilms was assessed by crystal violet staining, resazurin assay, compound bright field microscope, and confocal laser scanning microscope (CLSM). Moreover, the efficacy of phage phPE42 as a potential therapy was evaluated in a rat model.

KEY FINDINGS

A newly lytic Myoviridae phage phPE42 was isolated and exhibited broad coverage activity (48.6 %) against E. coli clinical isolates. It demonstrated favorable growth kinetics and relative stability under a variety of challenging conditions. The resazurin colorimetric assay and CLSM provided evidence of phage potential's ability to significantly (P < 0.05) decrease the viability of biofilm-embedded cells. The bacterial burden in animal faeces was effectively eradicated (P < 0.05) by oral administration of phage phPE42. Phage-treated rats exhibited a significant decrease in tissue damage with no signs of inflammation, necrosis, or erosion. Furthermore, phage therapy significantly (P < 0.05) reduced the expression level of the apoptotic marker caspase-3 and the inflammatory cytokine TNF-α.

SIGNIFICANCE

Treatment with phage phPE42 is considered a promising alternative therapy for the control of severe foodborne infections spurred by pathogenic XDR E. coli.

Antibacterial and anti-biofilm activity of diarylureas against Enterococcus faecium by suppressing the gene expression of peptidoglycan hydrolases and adherence

Enterococcus faecium (E. faecium) is a clinical multidrug-resistant pathogen causing life-threatening infection, which makes it important to discover antibacterial agents with novel scaffolds and unique mechanism. In this study, the diarylurea scaffold was found to have potent antibacterial effect on E. faecium. Diarylurea ZJ-2 with benign drug-like property exhibited potent antibacterial and anti-biofilm activity through inhibiting the genes expression of NlpC/p60 hydrolase-secreted antigen A (sagA) and autolysins (atlA), down-regulating the expression of biofilm adherence related genes aggregation substance (agg), enterococcal surface protein (esp) against E. faecium. Moreover, ZJ-2 can be docked into SagA to inhibit daughter cell separation. In a mouse model of abdominal infection, ZJ-2 decreased the bacterial load and the level of IL-6 and TNF-α in a time-dependent manner. Overall, these findings indicated that diarylurea ZJ-2 has the potential to be developed as a therapeutic agent to treat drug-resistant enterococci and biofilm-related infections.

Is sitagliptin effective for SARS-CoV-2 infection: false or true prophecy?

Coronavirus disease 2019 (Covid-19) is caused by severe acute respiratory syndrome type 2 (SARS-CoV-2). Covid-19 is characterized by hyperinflammation, oxidative stress, and multi-organ injury (MOI) such as acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Covid-19 is mainly presented with respiratory manifestations; however, extra-pulmonary manifestations may also occur. Extra-pulmonary manifestations of Covid-19 are numerous including: neurological, cardiovascular, renal, endocrine, and hematological complications. Notably, a cluster of differentiation 26 (CD26) or dipeptidyl peptidase-4 (DPP-4) emerged as a new receptor for entry of SARS-CoV-2. Therefore, DPP-4 inhibitors like sitagliptin could be effective in treating Covid-19. Hence, we aimed in the present critical review to assess the potential role of sitagliptin in Covid-19. DPP-4 inhibitors are effective against the increased severity of SARS-CoV-2 infections. Moreover, DPP-4 inhibitors inhibit the interaction between DPP-4 and scaffolding proteins which are essential for endosome formation and replication of SARS-CoV-2. Therefore, sitagliptin through attenuation of the inflammatory signaling pathway and augmentation of stromal-derived factor-1 (SDF-1) may decrease the pathogenesis of SARS-CoV-2 infection and could be a possible therapeutic modality in treating Covid-19 patients. In conclusion, the DPP-4 receptor is regarded as a potential receptor for the binding and entry of SARS-CoV-2. Inhibition of these receptors by the DPP-4 inhibitor, sitagliptin, can reduce the pathogenesis of the infection caused by SARS-CoV-2 and their associated activation of the inflammatory signaling pathways.

Silver Nanoparticles Prepared Using Encephalartos laurentianus De Wild Leaf Extract Have Inhibitory Activity against Candida albicans Clinical Isolates

Candida albicans is a major human opportunistic pathogen causing infections, which range from cutaneous to invasive systemic infections. Herein, the antifungal and anti-biofilm potential of silver nanoparticles (AgNPs) green synthesized in the presence of Encephalartos laurentianus leaf extract (ELLE) were investigated. The bioactive chemicals of ELLE, including phenolics, flavonoids, and glycosides were identified and quantified for the first time. AgNPs showed minimum inhibitory concentration (MIC) values against C. albicans clinical isolates ranging from 8 to 256 µg/mL. In addition, AgNPs significantly decreased biofilm formation. The impact of AgNPs on the expression of the genes encoding biofilm formation was assessed using qRT-PCR. AgNPs had a beneficial role in the macroscopic wound healing, and they resulted in complete epithelization without any granulation tissue or inflammation. Treatment with AgNPs resulted in negative immunostaining of tumor necrosis factor-α. The levels of the inflammation markers, interleukin-6 and interleukin-1β, significantly decreased (p < 0.05) in the AgNPs-treated group. There was also a pronounced increase in the gene expression of fibronectin and platelet-derived growth factor in the wound tissues. Thus, AgNPs synthesized using ELLE may be a promising antifungal and wound healing agent.

Zinc Oxide Nanoparticles as Potential Delivery Carrier: Green Synthesis by Aspergillus niger Endophytic Fungus, Characterization, and In Vitro/In Vivo Antibacterial Activity

We aimed to synthesize zinc oxide nanoparticles (ZnO NPs) using the endophytic fungal extract of Aspergillus niger. The prepared ZnO NPs were characterized, and their in vitro and in vivo antibacterial activity was investigated. Isolated endophytic fungus identification was carried out using 18S rRNA. A. niger endophytic fungal extract was employed for the green synthesis of ZnO NPs. The in vitro antibacterial activity of the prepared ZnO NPs was elucidated against Staphylococcus aureus using the broth microdilution method and quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, the in vivo antibacterial activity was elucidated using a systemic infection model in mice. The biosynthesized ZnO NPs showed a maximum optical density at 380 nm with characteristic peaks on the Fourier-transform infrared spectrum. The X-ray diffraction pattern was highly matched with a standard platform of zinc oxide crystals. Energy-dispersive X-ray analysis confirmed that the main composition of nanoparticles was zinc and oxygen atoms. Scanning and transmission electron microscopies showed spherical geometry with a smooth surface. Zeta potential measurements (26.6 ± 0.56 mV) verified the adequate stability of ZnO NPs. Minimum inhibitory concentrations of ZnO NPs against S. aureus isolates ranged from 8 to 128 µg/mL. Additionally, ZnO NPs revealed antibiofilm activity, resulting in the downregulation of the tested biofilm genes in 29.17% of S. aureus isolates. Regarding the in vivo experiment, ZnO NPs reduced congestion and fibrosis in liver and spleen tissues. They also improved liver function, increased the survival rate, and significantly decreased inflammatory markers (p < 0.05). ZnO NPs synthesized by A. niger endophytic fungus revealed a promising in vivo and in vitro antibacterial action against S. aureus isolates.

Bilosomes as Nanoplatform for Oral Delivery and Modulated In Vivo Antimicrobial Activity of Lycopene

Owing to the disseminating resistance among pathogenic bacteria, especially Klebsiella pneumoniae, there is a high need for alternate compounds with antibacterial activity. Herein, lycopene was isolated from Lycopersicon esculentum L. Molecular docking approach was employed to explore lycopene binding affinity to selected vital proteins of K. pneumoniae with the binding mechanisms being investigated. This proposed a promising antibacterial activity of lycopene. However, the pharmacological use of lycopene is hampered by its poor solubility and limited oral bioavailability. Accordingly, bilosomes were fabricated for oral lycopene delivery. The computed entrapment efficiency, mean vesicular size, and zeta potential values for the optimized formulation were 93.2 ± 0.6%, 485.8 ± 35.3 nm, and −38.3 ± 4, respectively. In vitro drug release studies revealed controlled lycopene release from constructed bilosomes, with the drug liberation being based on the Higuchi kinetics model. Transmission electron microscopic evaluation of bilosomes revealed spherical nanovesicles free from aggregates. Moreover, the in vitro and in vivo antibacterial activity of lycopene and its constructed formulations against multidrug-resistant K. pneumoniae isolates were explored. The optimized bilosomes exhibited the lowest minimum inhibitory concentrations ranging from 8 to 32 µg/mL. In addition, scanning electron microscopy revealed remarkable deformation and lysis of the bilosomes-treated bacterial cells. Regarding in vivo investigation, a lung infection model in mice was employed. The tested bilosomes reduced the inflammation and congestion in the treated mice’s lung tissues, resulting in normal-sized bronchioles and alveoli with very few congested vessels. In addition, it resulted in a significant reduction in pulmonary fibrosis. In conclusion, this study investigated the potential activity of the naturally isolated lycopene in controlling infections triggered by multidrug-resistant K. pneumoniae isolates. Furthermore, it introduced bilosomes as a promising biocompatible nanocarrier for modulation of oral lycopene delivery and in vivo antimicrobial activity.

Anti-Biofilm and Antibacterial Activities of Cycas media R. Br Secondary Metabolites: In Silico, In Vitro, and In Vivo Approaches

Enterococcus species possess many virulence factors that have an essential role in exacerbating the infections caused by them. The current study aimed to evaluate the effect of the secondary metabolites ginkgetin (GINK) and sotetsuflavone (SOTE), isolated from Cycas media R. Br dichloromethane fraction, on Enterococcus faecalis (E. faecalis) isolates for the first time. The antibacterial and antivirulence activities of the isolated compounds were investigated using docking studies and in vitro by determination of the minimum inhibitory concentrations (MICs). Additionally, flow cytometry and scanning electron microscope (SEM) were utilized to assess the effect of SOTE on the tested bacteria. Moreover, crystal violet assay and qRT-PCR were used to test the effect of SOTE on the biofilm-forming ability of E. faecalis isolates. In addition, a systemic infection model was utilized in vivo to investigate the antibacterial activity of SOTE. We found that both GINK and SOTE showed a good affinity for the five proteins enrolled in the virulence of E. faecalis, with SOTE being the highest, suggesting the possible mechanisms for the antivirulence activity of both ligands. In addition, SOTE exhibited a higher antibacterial activity than GINK, as the values of the MICs of SOTE were lower than those of GINK. Thus, we performed the in vitro and in vivo assays on SOTE. However, they did not exhibit any significant variations (p > 0.05) in the membrane depolarization of E. faecalis isolates. Moreover, as evaluated by SEM, SOTE caused distortion and deformation in the treated cells. Regarding its impact on the biofilm formation, it inhibited the biofilm-forming ability of the tested isolates, as determined by crystal violet assay and qRT-PCR. The in vivo experiment revealed that SOTE resulted in a reduction of the inflammation of the liver and spleen with an increase in the survival rate. SOTE also improved the liver-function tests and decreased tumor necrosis factor-alpha using immunostaining and the inflammation markers, interleukins (IL-1β and IL-6), using ELISA. Thus, we can conclude that SOTE could be a promising compound that should be investigated in future preclinical and clinical studies.

Encephalartos villosus Lem. Displays a Strong In Vivo and In Vitro Antifungal Potential against Candida glabrata Clinical Isolates

Recently, Candida glabrata has been recognized as one of the most common fungal species that is highly associated with invasive candidiasis. Its spread could be attributed to its increasing resistance to antifungal drugs. Thus, there is a high need for safer and more efficient therapeutic alternatives such as plant extracts. Here, we investigated the antifungal potential of Encephalartos villosus leaves methanol extract (EVME) against C. glabrata clinical isolates. Tentative phytochemical identification of 51 metabolites was conducted in EVME using LC–MS/MS. EVME demonstrated antifungal activity with minimum inhibitory concentrations that ranged from 32 to 256 µg/mL. The mechanism of the antifungal action was studied by investigating the impact of EVME on nucleotide leakage. Additionally, a sorbitol bioassay was performed, and we found that EVME affected the fungal cell wall. In addition, the effect of EVME was elucidated on the efflux activity of C. glabrata isolates using acridine orange assay and quantitative real-time PCR. EVME resulted in downregulation of the expression of the efflux pump genes CDR1, CDR2, and ERG11 in the tested isolates with percentages of 33.33%, 41.67%, and 33.33%, respectively. Moreover, we investigated the in vivo antifungal activity of EVME using a murine model with systemic infection. The fungal burden was determined in the kidney tissues. Histological and immunohistochemical studies were carried out to investigate the effect of EVME. We noticed that EVME reduced the congestion of the glomeruli and tubules of the kidney tissues of the rats infected with C. glabrata. Furthermore, it decreased both the proinflammatory cytokine tumor necrosis factor-alpha and the abnormal collagen fibers. Our results reveal, for the first time, the potential in vitro (by inhibition of the efflux activity) and in vivo (by decreasing the congestion and inflammation of the kidney tissues) antifungal activity of EVME against C. glabrata isolates.

The Mechanistic Perspective of Bilobetin Protective Effects against Cisplatin-Induced Testicular Toxicity: Role of Nrf-2/Keap-1 Signaling, Inflammation and Apoptosis

Cisplatin (CP) is a productive anti-tumor used to treat numerous tumors. However, multiple toxicities discourage prolonged use, especially toxicity on the reproductive system. This experiment was mapped out to determine the potential therapeutic impact of Bilobetin on CP-induced testicular damage. Herein, Bilobetin was isolated from Cycas thouarsii leaves R. Br ethyl acetate fractions for the first time. A single dose of CP (7 mg/kg, IP) was used to evoke testicular toxicity on the third day. Rats were classified into five groups; Normal control, Bilobetin 12 mg/kg, Untreated CP, and CP treated with Bilobetin (6 and 12 mg/kg, respectively) orally daily for ten days. Bilobetin treatment ameliorated testicular injury. In addition, it boosted serum testosterone levels considerably and restored relative testicular weight. Nevertheless, apoptosis biomarkers such as P53, Cytochrome-C, and caspase-3 decreased significantly. Additionally, it enhanced the testes’ antioxidant status via the activation of Nrf-2, inhibition of Keap-1, and significant elevation of SOD activity in addition to a reduction in lipid peroxidation. Histopathologically, Bilobetin preserved testicular architecture and improved testicular immunostaining of Ki67 substantially, showing evidence of testicular regeneration. Bilobetin’s beneficial effects on CP-induced testicular damage are associated with enhanced antioxidant effects, lowered apoptotic signals, and the restoration of testes’ regenerative capability. In addition, Bilobetin may be used in combination with CP in treatment protocols to mitigate CP-induced testicular injury.

Green Coffee Bean Extract Normalize Obesity-Induced Alterations of Metabolic Parameters in Rats by Upregulating Adiponectin and GLUT4 Levels and Reducing RBP-4 and HOMA-IR

Obesity is a serious public health issue worldwide. Finding safe and efficacious products to reverse obesity has proven to be a difficult challenge. This study showed the effects of Coffea arabica or green coffee bean extract (GCBE) on obesity disorders and the improvement of obesity-induced insulin resistance, dyslipidemia, and inflammation. The active constituents of GCBE were identified via high-performance liquid chromatography. Twenty-four male albino Wistar rats were divided into two groups. The first group (Group I) was fed a control diet, whereas the second group was fed a high-fat diet (HFD) for eight weeks till obesity induction. The second group was equally subdivided into Group II, which received HFD, and Group III, which received HFD + GCBE for another eight weeks. The body and organ weights of the animals were measured, and blood and adipose tissue samples were collected for analysis. The results indicated that the administration of GCBE significantly decreased the body and organ weights. Furthermore, it had an ameliorative effect on serum biochemical parameters. It dramatically reduced total cholesterol, triacylglycerol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, glucose, and insulin levels. In addition, an improvement in homeostasis model assessment-insulin resistance and an enhancement of high-density lipoprotein cholesterol levels were observed compared with the HFD group. In addition, the group treated with GCBE exhibited a marked increase in serum levels of adiponectin (an anti-inflammatory adipokine). In addition, a considerable reduction in adipocyte hypertrophy was found following GCBE treatment. Remarkably, the administration of GCBE resulted in a remarkable decrease in the expression of RBP4 (a pro-inflammatory cytokine), whereas an increase in GLLUT4 expression was observed in the adipose tissue. This improved insulin resistance in GCBE-administered HFD rats compared with other HFD rats. Our study showed that GCBE exhibits anti-obesity activity and may be used as a natural supplement to prevent and treat obesity and its associated disorders.

Promising Antifungal Activity of Encephalartos laurentianus de Wild against Candida albicans Clinical Isolates: In Vitro and In Vivo Effects on Renal Cortex of Adult Albino Rats

Candida albicans can cause various infections, especially in immunocompromised patients. Its ability to develop resistance to the current antifungal drugs as well as its multiple virulence factors have rendered the problem even more complicated. Thus, in the present investigation, we elucidated an in vitro and in vivo antifungal activity of Encephalartos laurentianus methanol extract (ELME) against C. albicans clinical isolates for the first time. A phytochemical identification of 64 compounds was conducted in ELME using LC-MS/MS. Interestingly, ELME exhibited antifungal activity with MIC values that ranged from 32–256 µg/mL. Furthermore, we investigated the antibiofilm activity of ELME against the biofilms formed by C. albicans isolates. ELME displayed antibiofilm activity using a crystal violet assay as it decreased the percentages of cells, moderately and strongly forming biofilms from 62.5% to 25%. Moreover, the antibiofilm impact of ELME was elucidated using SEM and fluorescent microscope. A significant reduction in the biofilm formation by C. albicans isolates was observed. In addition, we observed that ELME resulted in the downregulation of the biofilm-related tested genes (ALS1, BCR1, PLB2, and SAP5) in 37.5% of the isolates using qRT-PCR. Besides, the in vivo antifungal activity of ELME on the kidney tissues of rats infected with C. albicans was investigated using histological and immunohistochemical studies. ELME was found to protect against C. albicans induced renal damage, decrease desmin and inducible nitric oxide synthase, increase alkaline phosphatase, and increase infected rats’ survival rate. Additionally, the cytotoxicity of ELME was elucidated on Human Skin Fibroblast normal cells using MTT assay. ELME had an IC50 of 31.26 µg/mL. Thus, we can conclude that ELME might be a promising future source for antifungal compounds.