Dihydrophenazine: a multifunctional new weapon that kills multidrug-resistant Acinetobacter baumannii and restores carbapenem and oxidative stress susceptibilities.

AIMS: The current work aims to fully characterize a new antimicrobial agent against Acinetobacter baumannii, which continues to represent a growing threat to healthcare settings worldwide. With minimal treatment options due to the extensive spread of resistance to almost all the available antimicrobials, the hunt for new antimicrobial agents is a high priority. METHODS AND RESULTS: An Egyptian soil-derived bacterium strain NHM-077B proved to be a promising source for a new antimicrobial agent. Bio-guided fractionation of the culture supernatants of NHM-077B followed by chemical structure elucidation identified the active antimicrobial agent as 1-hydroxy phenazine. Chemical synthesis yielded more derivatives, including dihydrophenazine (DHP), which proved to be the most potent against A. baumannii, yet it exhibited a marginally safe cytotoxicity profile against human skin fibroblasts. Proteomics analysis of the cells treated with DHP revealed multiple proteins with altered expression that could be correlated to the observed phenotypes and potential mechanism of the antimicrobial action of DHP. DHP is a multipronged agent that affects membrane integrity, increases susceptibility to oxidative stress, interferes with amino acids/protein synthesis, and modulates virulence-related proteins. Interestingly, DHP in subinhibitory concentrations re-sensitizes the highly virulent carbapenem-resistant A. baumannii strain AB5075 to carbapenems providing great hope in regaining some of the benefits of this important class of antibiotics. CONCLUSIONS: This work underscores the potential of DHP as a promising new agent with multifunctional roles as both a classical and nonconventional antimicrobial agent that is urgently needed.

Biosynthesis and Characterization of Aeonium arboreum-Derived Silver Nanoparticles: Antimicrobial Activity, Biofilm Inhibition, Antihemolytic Activity, and In Silico Studies.

Environmentally friendly biosynthesis of silver nanoparticles (AgNPs) from Aeonium arboreum (L.) Webb & Berthel is reported for the first time. The synthesized AgNPs were characterized using UV-Vis, FTIR, TEM, Zeta potential, and XRD analysis, revealing high stability (-29.1 mV), spherical shape, and an average size of 100 nm. The antimicrobial activity levels of both A. arboreum extract and biosynthesized AgNPs were evaluated against five uropathogens (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans). Both the extract and the AgNPs exhibited significant efficacy, particularly against E. coli, with inhibition zones of 27 mm and 30 mm, respectively. LC-MS analysis tentatively identified 11 secondary metabolites in the extract, including quercetin-3-O-glucoside, quercetin-3-O-rhamnoside, myricetin 3-glucoside, and daphneresinol. In silico docking studies revealed promising binding affinities of these metabolites in relation to key enzymes involved in bacterial folate synthesis (dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS)) and DNA replication (DNA gyrase). These findings demonstrate the potential of A. arboreum-based AgNPs and their associated metabolites as a novel therapeutic approach for combating urinary tract infections. Their antimicrobial, antihemolytic, and antibiofilm properties warrant further investigation.

LC-QToF chemical profiling of Euphorbia grantii Oliv. and its potential to inhibit LPS-induced lung inflammation in rats via the NF-κB, CY450P2E1, and P38 MAPK14 pathways.

Acute lung injury (ALI) is a life-threatening syndrome that causes high morbidity and mortality worldwide. The aerial parts of Euphorbia grantii Oliv. were extracted with methanol to give a total methanolic extract (TME), which was further fractionated into dichloromethane (DCMF) and the remaining mother liquor (MLF) fractions. Biological guided anti-inflammatory assays in vitro revealed that the DCMF showed the highest activity (IC50 6.9 ± 0.2 µg/mL and 0.29 ± 0.01 µg/mL) compared to. celecoxib (IC50 of 88.0 ± 1 µg/mL and 0.30 ± 0.01 µg/mL) on COX-1 and COX-2, respectively. Additionally, anti-LOX activity was IC50 = 24.0 ± 2.5 µg/mL vs. zileuton with IC50 of 40.0 ± 0.5 µg/mL. LC-DAD-QToF analysis of TME and the active DCMF resulted in the tentative identification and characterization of 56 phytochemical compounds, where the diterpenes were the dominated metabolites. An LPS-induced inflammatory model of ALI (10 mg/kg i.p) was used to assess the anti-inflammatory potential of DCMF in vivo at dose of 200 mg/kg and 300 mg/kg compared to dexamethasone (5 mg/kg i.p). Our treatments significantly reduced the pro-inflammatory cytokines (TNF-α, IL-1, IL-6, and MPO), increased the activity of antioxidant enzymes (SOD, CAT, and GSH), decreased the activity of oxidative stress enzyme (MDA), and reduced the expression of inflammatory genes (p38.MAPK14 and CY450P2E1). The western blotting of NF-κB p65 in lung tissues was inhibited after orally administration of the DCMF. Histopathological study of the lung tissues, scoring, and immunohistochemistry of transforming growth factor-beta 1 (TGF-ß1) were also assessed. In both dose regimens, DCMF of E. grantii prevented further lung damage and reduced the side effects of LPS on acute lung tissue injury.

α-Glucosidase, butyrylcholinesterase and acetylcholinesterase inhibitory activities of phenolic compounds from Carthamus tinctorius L. flowers: In silico and in vitro studies.

Chemical investigation of Carthamus tinctorius L. flowers resulted in isolation of seven metabolites that were identified as; p-Hydroxybenzoic acid (1), trans hydroxy cinnamic acid (2), kaempferol-6-C-glucoside (3), astragalin (4), cartormin (5), kaempferol-3-O-rutinoside (6), and kaempferol-3-O-sophoroside (7). Virtual screening of the isolated compounds against human intestinal α-glucosidase, acetylcholinesterase, and butyrylcholinesterase was carried out. Additionally, the antioxidant activity of the bioactive compounds was assessed. Compounds 1 and 5 exhibited moderate binding affinities to acetylcholinesterase (binding energy -5.33 and -4.18 kcal/mol, respectively), compared to donepezil (-83.33kcal/mol). Compounds 1-7 demonstrated weak affinity to butyrylcholinesterase. Compounds 2 and 4 displayed moderate binding affinity to human intestinal α-glucosidase,compared to Acarbose (reference compound), meanwhile compound 2 exhibited lower affinity. Molecular dynamic studies revealed that compound 4 formed a stable complex with the binding site throughout a 100 ns simulation period. The in-vitro results were consistent with the virtual experimental results, as compounds 1 and 5 showed mild inhibitory effects on acetylcholinesterase (IC50s 150.6 and 168.7 µM, respectively). Compound 4 exhibited moderate α-glucosidase inhibition with an IC50 of 93.71 µM. The bioactive compounds also demonstrated notable antioxidant activity in ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)], ORAC (oxygen radical-absorbance capacity), and metal chelation assays, suggesting their potential in improving dementia in Alzheimer's disease (AD) and mitigating hyperglycemia.

Feature-Based Molecular Networking for the Exploration of the Metabolome Diversity of Common Egyptian Centaurea Species in Relation to Their Cytotoxic Activity.

Centaurea is a genus compromising over 250 herbaceous flowering species and is used traditionally to treat several ailments. Among the Egyptian Centaurea species, C. lipii was reported to be cytotoxic against multidrug-resistant cancer cells. In this context, we aimed to explore the metabolome of C. lipii and compare it to other members of the genus in pursuance of identifying its bioactive principles. An LC-MS/MS analysis approach synchronized with feature-based molecular networks was adopted to offer a holistic overview of the metabolome diversity of the Egyptian Centaurea species. The studied plants included C. alexandrina, C. calcitrapa, C. eryngioides, C. glomerata, C. lipii, C. pallescens, C. pumilio, and C. scoparia. Their constitutive metabolome showed diverse chemical classes such as cinnamic acids, sesquiterpene lactones, flavonoids, and lignans. Linking the recorded metabolome to the previously reported cytotoxicity identified sesquiterpene lactones as the major contributors to this activity. To confirm our findings, bioassay-guided fractionation of C. lipii was adopted and led to the isolation of the sesquiterpene lactone cynaropicrin with an IC50 of 1.817 µM against the CCRF-CEM leukemia cell line. The adopted methodology highlighted the uniqueness of the constitutive metabolome of C. lipii and determined the sesquiterpene lactones to be the responsible cytotoxic metabolites.

SIRT1/Nrf2/NF-κB Signaling Mediates Anti-Inflammatory and Anti-Apoptotic Activities of Oleanolic Acid in a Mouse Model of Acute Hepatorenal Damage.

Background and objectives: Oleanolic acid (OA) is a penta-cyclic triterpene with diverse bioactivities such as anticarcinogenic, antiviral, antimicrobial, hepatoprotective, anti-atherosclerotic, hypolipidemic, and gastroprotective. However, its effects on hepatorenal damage remain unclear. The protective activity of OA, separated from Viscum schimperi (Loranthaceae), against TAA (thioacetamide)-produced acute hepatic and renal damage was explored. Materials and Methods: Mice were treated with OA for 7 days before TAA (200 mg/kg, i.p.). Serum indices of hepatorenal injury, pathological lesions, molecular biological indexes, and inflammatory/apoptotic genes were estimated. Results: The tissues of both organs were greatly affected by the TAA injection. That was evident through increased serum markers of hepato-renal injury as well as remarkable histopathological lesions. TAA-induced injury was associated with oxidative and inflammatory responses in both organs as there was an elevation of oxidative stress parameters (4-HNE (4-hydroxy-nonenal), MDA (malondialdehyde), NOx (nitric oxide)), decline of antioxidants (reduced glutathione (GSH), superoxide dismutase (SOD), and total antioxidant capacity (TAC)), and an increase in the gene expression/level of inflammatory mediators (interleukins (1ß&6)). The inflammatory response was linked to a significant activation of NF-κB (nuclear-factor kappa-B)/TNF-α (tumor-necrosis factor-alpha) signaling. The inflammatory response in both organs was accompanied by apoptotic changes, including a rise in the gene expression and level of apoptotic parameters (caspase-3 and Bax) along with a decline in Bcl-2 (anti-apoptotic parameter) gene expression and level. These pathogenic events were found to be closely related to the suppression of the antioxidant signaling pathway, Nrf2 (nuclear-factor erythroid 2-related factor-2)/SIRT1 (sirtuin-1)/HO-1 (heme-oxygenase 1). On the other hand, OA significantly ameliorated TAA-induced injury in both organs. On the other hand, OA counterpoised the inflammatory response as it ameliorated NF-κB/TNF-α signaling and cytokine release. OA enhanced Nrf2/SIRT1/HO-1 signaling and counteracted apoptotic damage. Conclusions: OA showed anti-inflammation and antiapoptotic capacities that effectively suppressed TAA-induced acute hepatorenal damage.

Natural Reno-Protective Agents against Cyclosporine A-Induced Nephrotoxicity: An Overview.

CA (cyclosporine A) is a powerful immunosuppressing agent that is commonly utilized for treating various autoimmune illnesses and in transplantation surgery. However, its usage has been significantly restricted because of its unwanted effects, including nephrotoxicity. The pathophysiology of CA-induced kidney injury involves inflammation, apoptosis, tubular injury, oxidative stress, and vascular injury. Despite the fact that exact mechanism accountable for CA's effects is inadequately understood, ROS (reactive oxygen species) involvement has been widely proposed. At present, there are no efficient methods or drugs for treating CA-caused kidney damage. It is noteworthy that diverse natural products have been investigated both in vivo and in-vitro for their possible preventive potential in CA-produced nephrotoxicity. Various extracts and natural metabolites have been found to possess a remarkable potential for restoring CA-produced renal damage and oxidative stress alterations via their anti-apoptosis, anti-inflammatory, and antioxidative potentials. The present article reviews the reported studies that assess the protective capacity of natural products, as well as dietary regimens, in relation to CA-induced nephrotoxicity. Thus, the present study presents novel ideas for designing and developing more efficient prophylactic or remedial strategies versus CA passive influences.

Phytochemical profile, enzyme inhibition activity and molecular docking analysis of Feijoa sellowiana O. Berg.

Feijoa sellowiana leaves and fruits have been investigated as a source of diverse bioactive metabolites. Extract and eight metabolites isolated from F. sellowiana leaves were evaluated for their enzymatic inhibitory activity against α-glucosidase, amylase, tyrosinase, acetylcholinestrerase and butyrylcholinesterase both in vitro and in silico. Feijoa leaves' extract showed strong antioxidant activity and variable levels of inhibitions against target enzymes with a strong anti-tyrosinase activity (115.85 mg Kojic acid equivalent/g). Additionally, α-tocopherol emerged as a potent inhibitor of AChE and BChE (5.40 & 10.38 mmol galantamine equivalent/g, respectively). Which was further investigated through molecular docking and found to develop key enzymatic interactions in AChE and BChE active sites. Also, primetin showed good anti BChE (11.70 mmol galantamine equivalent/g) and anti-tyrosinase inhibition (90.06 mmol Kojic acid equivalent/g) which was also investigated by molecular docking studies. Highlights Isolation of eight bioactive constituents from Feijoa sellowiana leaves. In vitro assays using different enzymatic drug targets were investigated. In silico study was performed to define compound interactions with target proteins. Feijoa leaf is an excellent source of anti-AChE and antityrosinase bioactives.

Natural Peroxisome Proliferator-Activated Receptor γ (PPARγ) Activators for Diabetes.

CONTEXT: Metabolic syndrome (MetS) represents a worldwide problem. Drugs used in MetS target different symptoms, like excessive body weight, insulin resistance, hyperglycemia, dyslipidemia, or hypertension. Peroxisome proliferator-activated receptors (PPAR) regulate the gene expression involved in lipid metabolism, inflammation, and adipogenesis. Activation of PPARγ has become a target of interest to counter hyperglycemia linked with MetS and type 2 diabetes (T2DM). OBJECTIVE: The current review intended to summarize reported research on medicinal plants, or their bioactive constituents, with PPARγ-activating potential. DESIGN: The research team searched the literature up to 2016 using electronic databases- ScienceDirect, PubMed, Google-Scholar, SpringerLink, Scopus, and Wiley-for publications on medicinal plants with promising PPARγ modulators using keywords diabetes mellitus, natural products, peroxisome proliferator-activated receptors, metabolic syndrome, adipogenesis. SETTING: This study was conducted in the Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia, Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt, and Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah, Al Munawwarah, Saudi Arabia. RESULTS: Several natural products were considered to be good ligands for PPARγ. The PPARγ agonistic activity of over 100 plants covered in this review was supported by experimental evidence. Some of the plants and their constituents had been studied for their possible mechanisms of action. CONCLUSIONS: Findings discussed in this review highlighted PPARγ's role as an organizer of lipid metabolism and glucose homeostasis, thus supporting its function as a target for antidiabetic agents. The discovery that some natural compounds and plants could activate PPARγ opens up the prospect for future development of strategies to take advantage of its therapeutic potential in diabetes. Therefore, the current review could provide significant information for biotechnological or pharmaceutical applications in targeted drug delivery and design.

Bioassay Guided Isolation and Docking Studies of a Potential ß-Lactamase Inhibitor from Clutia myricoides.

Infectious diseases are the second major cause of death worldwide, and the ability to resist multiple classes of antibiotics is the key factor in enabling pathogenic organisms to survive and spread in the nosocomial environment. Unfortunately, the available ß-lactamase inhibitors are not efficient against ß-lactamase B, C, and D which necessitates discovering either broad spectrum ß-lactamase inhibitors or new ß-lactam antibiotics resistant to bacterial enzymes. In this regard, products of natural origin have prompted the disclosure of new compounds and medicinal leads. Chloroform fraction of Clutia myricoides (Soa'bor) showed a pronounced activity against extended-spectrum ß-lactamase (ESBL) strains. Bio-guided fractionation resulted in isolation of two new compounds; 2-methoxy chrysophanol (2) and Saudin-I (5) in addition to three known compounds that were identified as chrysophanol (1), stigmasterol (3) and ß-sitosterol (4). Antibacterial and anti ESBL activities of the isolated compounds were performed. No antibacterial activities were detected for any of the tested compounds. Meanwhile, compound 2 showed promising anti ESBL activity. Compound 2 has shown an obvious activity against K. pneumoniae ATCC 700603 with a marked enlargement of inhibition zones (>5mm) in combination with third generation cephalosporin antibiotics. To further understand the mechanism of action of compound 2, molecular docking was carried out against CTX-M-27 ESBL. The results showed binding site interactions strikingly different from its analogue, compound 1, allowing compound 2 to be active against ESBL. These results proposed the concomitant use of these active compounds with antibiotics that would increase their efficiency. Nevertheless, the interaction between this active compound and antibiotics should be taken into consideration. Therefore, in order to evaluate the safety of this active compound, further in vitro and in vivo toxicity assays must be carried out.