Resazurin Dye Research Articles

Effect of seasonal variations on phytoconstituents and antimicrobial properties of Holoptelea integrifolia, an important medicinal plant from Kangra District in Himachal Pradesh, India: A case study

Medicinal plants have been used for the treatment of many ailments since time immemorial. The pharmacological significance of these plants is attributed to the presence of secondary metabolites which are greatly affected by the changes in the climatic conditions. This study investigates the effect of seasonal variations on the phytochemical constituents and biological activities of Holoptelea integrifolia leaves and bark in Kangra district, Himachal Pradesh, India. The antimicrobial activity and minimum inhibitory concentration of various plant extracts were determined using agar well diffusion and resazurin dye methods. The qualitative and quantitative analysis of phytochemical, besides antioxidant activity, were compared in all samples during different seasons. The experimental results revealed that the chloroform extracts of leaves and bark of plants during winter season were most effective against S. flexneri with highest zone of inhibition (ZOI) of 19.5±0.12mm and 22.6 ±0.32mm at 4 mg/40 μμl, respectively. However, MIC of leaf and bark extracts in case of S. flexneri were 0.3125 mg/100 μl and 0.0781 mg/100 μl, respectively. Phytochemical analysis of H. integrifolia confirmed significant seasonal variation, with phenols, flavonoids and terpenoids highest in the winter season, while alkaloids dominated in autumn season. The chloroform extract of H. integrifolia leaves and bark exhibited highest antioxidant activity in DPPH assay (78.81±0.12% & 81.41±0.24%) followed by H2O2 and phosphomolybdenum at 300μg/ml conc. respectively. The results of the present work revealed that the bark of H. integrifolia during winter season exhibited better antimicrobial activity than the leaves, providing a valuable basis for the future efforts in developing novel herbal drugs.

Evaluation of Antibacterial Activity and Synergistic Interaction between Punica granatum peels and Synthetic Antibiotics on Multidrug-Resistant Bacteria

IntroductionAntibiotic resistance threatens global health, necessitating the development of new antimicrobial medications. Novel drugs can reverse drug resistance and revitalize the antibiotic arsenal. Therefore, this study aimed to evaluate the synergistic antibacterial effect of Punica granatum (P. granatum) extract and antibiotics against multidrug-resistant bacteria (MDR). MethodsPreliminary susceptibility profiling of the antibiotics, the antibacterial activity of the extract, and synergistic interactions between the extract and the three antibiotics were conducted using well diffusion and micro-broth dilution assays with resazurin dye. The inhibition zones (IZs), minimum inhibitory concentrations (MICs), and Fractional Inhibition Concentration Index (FICI) were determined. The data were analyzed using statistical software program (SPSS 26). ResultsThe bacterial isolates exhibited resistance to all antibiotics, except E. coli and P. aeruginosa were sensitive to Ciprofloxacin. P. granatum extract demonstrated an inhibitory effect on all tested bacteria. The FICI values for MDR strains ranged from (0.12 to 0.53), and the best synergistic effect was observed when Augmentin and Ciprofloxacin were combined against these strains. The FICI indices for the combination of P. granatum and Azithromycin ranged from (0.12 to 0.53). ConclusionThis study identified P. granatum extract as a potential adjunctive therapy to antibiotics for the treatment of multidrug-resistant bacteria.

ANTIOXIDANT AND CYTOTOXIC EFFECTS OF ESSENTIAL OILS EXTRACTED FROM Viola odorata L. CULTIVATED IN IRAQ

This study was aimed to determine the composition of essential oil contained in Viola odorata flowers and leaves. As well as assessing the cytotoxic effects of this oil on cancer cells and its antioxidant properties. A GC-Mass analysis was conducted to reveal essential oil components in flowers and leaves. For testing the antioxidant capacity of flowers and leaves oil, DPPH (1,1 Dyphenyl-2-picrylhydrazyl), resazurin dye, and hydroxyl were used. An in vitro study was conducted using lung cancer (A549) and breast normal (MCF-10) cell lines with concentrations of 25, 50, 100, 200, and 300 µl/ml of V. odorata L. essential oil. According to the results, essential oils derived from flowers and leaves contain different components in terms of quality and quantity. At a concentration of 300 µl/ml, the results showed that flowers' essential oil was highly antioxidant (98.16 %, 92.47%, 94.00 %) when combined with DPPH, resazurin dye, and hydroxyl, respectively. There was variation in cytotoxic effects on cancer cells based on oil concentrations and sources (flowers and leaves). In conclusion, the A549 cell line was significantly affected by flower oil than by leaves oil. The highest effect of flower oil was observed at a concentration of 300 µl/ml.

In vitro antimicrobial activity of non-traditional therapies for infectious endometritis in mares.

Endometritis is the leading cause of subfertility in horses, and it is a clinical problem where historically antibiotics have not always been used with prudent justification. Because of this, alternative therapies to treat endometritis are necessary for the rational use of antibiotics. To assess the in vitro antimicrobial activity of non-traditional therapies commonly used in clinical practice against microorganisms causing infectious endometritis in mares. In vitro experiments. A microdilution technique was performed to determine the minimum inhibitory concentrations (MIC) of 50%, 90% and 100% of microorganisms and the percentage of inhibition (PI) of each therapy against each microorganism (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Candida sp.). The MIC 50% and 90% were determined using non-linear regression, while MIC 100% was assessed using the resazurin dye technique. The serial PI was evaluated for each therapy using a spectrophotometer. All the therapies demonstrated a PI higher than positive controls for all microorganisms (p < 0.05); however, the only therapies that presented MIC 100 values were hydrogen peroxide and platelet-rich and -poor plasma. In vivo, safety and treatment efficacy were not tested. Hydrogen peroxide and platelet-rich and -poor plasma might be alternatives to traditional therapies for endometritis to support a reduction in antibiotic use.

Evaluation of Biocides Susceptibility and Expression of Qace-Δ1 And Suge1 Genes of Pseudomonas Aeruginosa in Exposure to Biocides and Meropenem

Pseudomonas aeruginosa is a species of medical significance that plays a role in nosocomial infections, particularly those resulting from burns and wounds. Bacterial antibiotic resistance may have developed as a result of the abuse of biocides in hospitals. This study aimed to determine the minimum inhibitory concentrations (MICs) of carbapenem-resistant P. aeruginosa isolates in relation to ethylenediaminetetraacetic acid (EDTA), chlorohexidine (CHX), and resazurin dye using a microtiter plate assay. Additionally, it evaluated the expression of the efflux pump genes (qacE-Δ1 and sugE1) at sub-inhibitory concentrations of the biocides using RT-qPCR (delta delta Ct method) to improve their efflux pump system. The MICs of 24 P. aeruginosa isolates (14 isolates were resist to carbapenems and 10 isolates sensitive to carbapenems) against Chloroxylenol (Dettol) revealed that the range of MICs were (0. 125-2%). The results of MICs of Chlorohexidine (CHX) revealed that the range of inhibitory activity was (0.8-102.4 µg/ml), also the findings of MICs of EDTA demonstrated that the range of inhibitory activity was (125-2000 µg/ml). The genes involved in efflux pump (qacE -Δ1 and sugE1) were found to be significantly up-regulated in the local isolates, according to our findings.. The four isolates' sugE1 gene expression folds ranged from 1.81 to 5.39; this result was more than the fold of the control (the fold change is 1), with the meropenem isolate having the highest fold value (5.39) and sub-MIC value (8 µg/ml). Furthermore, the four isolates' qacE-Δ1 gene expression folds ranged from 2.11 to 5.01, which was higher than the fold of the control, where the highest fold value was recorded for the EDTA (5.01) with the sub-MIC value (125-500 µg/ml). Also, a high value of upregulation of the gene qacE –Δ1, during the treatment with dettol with sub-MIC (0.25-0.5%), and the fold change was 4.19. In conclusion, the present findings indicated to the significant relationship between the treatments with meropenem and the high values of gene expression of the gene sugE1 in comparison with the control and other agents, Furthermore, compared to the antibiotic and control, there was a strong correlation found between the high fold changes of the gene qacE -Δ1 with the presence of dettol and EDTA.

Determination of valsartan drug by ion pair complex formation method in tablet form

A rapid, simple, sensitive, spectroscopic, ion pair complex method was developed for valsartan (VAL ) in pharmaceutical forms. Resazurin dye was used to form an ion pairing complex with the drug valsartan. analytical characteristics of the proposed method are Beer’s law range =10-60 (μg/mL), correlation coefficient (R2) = 0.9976 , limit of detection (LOD) = 0.1076(µg/mL), limit of quantification (LOQ) = 0.3261 (µg/mL), recovery percentage (%Rec) = (101.9626% - 95.6074%), relative standard deviation (%RSD)= 0.6188% - 0.7148%, Molar absorption (ε)= 4659.85(L/mol.cm), Sandell's index(S) = 0.093458(μg/cm2),at wavelength 495 nm . The results showed high accuracy and precision of the proposed quantification method for the valsartan drug , and it was of high accuracy and consistent.

Protective Effects of Chitosan-Loaded Pomegranate Peel Extract Nanoparticles on Infertility in Diabetic Male Rats.

Diabetes Mellitus (DM) is known to have an impact on the health of the male reproductive system. It is linked to low sperm quality, increased oxidative stress, and an increased generation of reactive oxygen species in the seminal fluid. Pomegranate extract has phenolic compounds and significant protective properties against oxidative stress, male sex hormone disruptions, and sperm abnormalities. The current study aimed to evaluate the effectiveness of Pomegranate Peel Extract Nanoparticles (PPENPs) on male fertility in diabetic rats. DM was induced in rats by intraperitoneal injection of streptozotocin (60 mg/kg). Twenty-four rats were divided into four groups, 6 rats in each group: control, DM, DM+empty NPs (60 mg/kg, orally), and DM+PPENPs (60 mg/kg, orally). Administration of PPENPs increased the levels of insulin, FSH, LH, testosterone, catalase, glutathione reduced, and semen fructose. PPENPs also improved sperm quality, as seen by improvements in sperm morphology, motility, count, and the ability of metabolically active spermatozoa to convert blue resazurin dye to pink resorufin. However, PPENPs decreased levels of glucose, malonaldehyde, nitric oxide, and sperm abnormalities. Also, histological investigation of the PPENPs showed improvement in testis tissue architecture and increased the diameter size of seminiferous tubules and germinative layer thickness. Our investigation proved that the treatment of PPENPs has a protective effect on the reproductive system of male diabetic rats, improving fertility parameters, healthy sperm profiles, and the antioxidant system.

Equine uterine sanitizer: in vitro inhibition of endometritis-causing microorganisms and its stability to dilute antibiotics

Endometritis is the leading cause of mare subfertility. Most mares respond to standard therapy, but alternative therapies have been developed for mares failing to respond. This study aimed to investigate a commercially available, yet unassessed, product labeled as a uterine sanitizer to determine the in vitro antimicrobial activity against microorganisms associated with endometritis and its in vitro stability to dilute antibiotics. In experiment 1, the microdilution broth technique and antimicrobial effects were assessed against Escherichia sp, Staphylococcus sp., Klebsiella sp., Pseudomonas sp., and Candida sp. Percentage inhibition was calculated by comparing the optical density. The minimum inhibitory concentration (MIC) 100% was determined using the resazurin dye technique. MIC 50% and 90% were determined using a dose-response non-linear regression. In experiment 2, the uterine sanitizer was used to dilute commonly used antibiotics achieving a final volume of 90 mL at 5°C, 21°C, and 37°C. The pH was measured at 0, 1, 3, 6, and 24 h after dilution. The uterine sanitizer had inhibitory properties against all microorganisms; Escherichia sp. being the most susceptible, and Pseudomonas sp. the most resistant. The uterine sanitizer had an acidic pH=4; however, when combined with the antibiotics, the pH of the antibiotic remained unchanged with the different temperatures and did not precipitate. In conclusion, the uterine sanitizer showed antimicrobial effects against endometritis-causing microorganisms. The dilution of antibiotics in the uterine sanitizer was stable and this association could potentiate the antimicrobial effects. Uterine sanitizer's safety and clinical efficacy in vivo remain to be tested.

Antibacterial and antioxidant activities of Alcea kurdica flower, leaf and root aqueous and organic extracts

Global concerns are rising due to complications associated with the use of chemical agents and antibiotic resistance. Consequently, research focus has shifted towards the quest for effective agents of biological origin. The aim of the present study was to assess the antioxidant and antimicrobial potentials of aqueous and organic extracts derived from various parts of Alcea kurdica. Different parts of A. kurdica were obtained and prepared into leaf, flower and root powders. The powders were extracted with aqueous and organic solvents. The antimicrobial activity of these extracts was assessed against bacterial pathogens using the agar well-diffusion assay. Additionally, the antioxidant effects of the extracts were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) and resazurin dye scavenging assays. The results showed dose-dependent antibacterial activity against Staphylococcus aureus and Escherichia coli for both the organic and aqueous leaf and floral extracts. Furthermore, an antioxidant effect (&gt;80%) was also observed for the organic and water extracts of the flowers, leaves and roots of the plant at the highest concentration (500 µg/ml), as compared to ascorbic acid, which served as the positive control using both the DPPH and resazurin methods. The findings of this study highlighted that A. kurdica can be considered a rich source of potential antioxidant and antibacterial agents, warranting future investigation to identify its active ingredients.

Analysis of the Molecular Structure of Hydroxychavicol, a Promising Oral Antibacterial

Abstract Objectives In order to better understand hydroxychavicol’s effectiveness as an oral antibacterial, its structural components were analyzed with respect to minimum inhibitory concentrations and minimum bactericidal concentrations against various oral bacteria. These structural components include the free hydroxy groups and allyl chain connected to hydroxychavicol’s benzene core. Methods Six structural analogs of hydroxychavicol were tested against a range of oral bacteria using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. MIC results were obtained using serial microdilution techniques in 96-well plates with resazurin dye as a colorimetric indicator. Aliquots within each MIC concentration range were then placed on appropriate agar medium and the minimum bactericidal concentration was determined as the lowest concentration with no observed colony growth. Key Findings A synergistic interaction was observed between the allyl chain and hydroxy groups on the benzene core of hydroxychavicol, which resulted in lower MICs against the tested oral bacteria. It was also found that a hydroxy group para to the allyl chain on the benzene ring resulted in more effective inhibition, with a MIC of &amp;lt;50 μg/mL against R. dentocariosa. Additionally, analytes possessing free hydroxy groups ortho to one another on the benzene ring resulted in MICs of 200-300 μg/mL or lower, whereas analytes with free hydroxy groups meta to one another on the benzene ring exhibited MICs of &amp;gt;1000 μg/mL. Conclusions This study helps elucidate the structural components responsible for hydroxychavicol’s effectiveness as an oral antibacterial. The findings herein help to understand the mechanism of hydroxychavicol’s antibacterial properties and will be helpful in the design and synthesis of more effective oral antibacterial treatments.

Low Oxygen Concentration Reduces Neisseria gonorrhoeae Susceptibility to Resazurin.

Neisseria gonorrhoeae has developed resistance to every antibiotic currently approved for the treatment of gonorrhea, prompting the development of new therapies. The phenoxazine dye resazurin exhibits robust antimicrobial activity against N. gonorrhoeae in vitro but fails to limit vaginal colonization by N. gonorrhoeae in a mouse model. The lack of in vivo efficacy may be due to oxygen limitation as in vitro susceptibility assays with resazurin are conducted under atmospheric oxygen while a microaerophilic environment is present in the vagina. Here, we utilized broth microdilution assays to determine the susceptibility of N. gonorrhoeae to resazurin under low and atmospheric oxygen conditions. The minimal inhibitory concentration of resazurin for multiple N. gonorrhoeae clinical isolates was significantly higher under low oxygen. This effect was specific to resazurin as N. gonorrhoeae was equally susceptible to other antibiotics under low and atmospheric oxygen conditions. The reduced susceptibility of N. gonorrhoeae to resazurin under low oxygen was largely attributed to reduced oxidative stress, as the addition of antioxidants under atmospheric oxygen mimicked the reduced susceptibility to resazurin observed under low oxygen. Together, these data suggest oxygen concentration is an important factor to consider when evaluating the efficacy of new antibiotics against N. gonorrhoeae in vitro.

Biological evaluation of levofloxacin and its thionated derivatives: antioxidant activity, aldehyde dehydrogenase enzyme inhibition, and cytotoxicity on A549 cell line.

Levofloxacin (LVX) is among the fluoroquinolones antibiotics that has also been studied in vitro and in vivo for its anticancer effects. In this study, we used LVX and novel LVX thionated derivatives; compounds 2 and 3, to evaluate their antioxidant activity, aldehyde dehydrogenase (ALDH) enzymes activity inhibition, and anticancer activity. Combination treatments with doxorubicin (DOX) were investigated as well. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to determine the antioxidant activity. The NADH fluorescence spectrophotometric activity assay was used to determine the ALDH inhibitory effects. Resazurin dye method was applied for cell viability assays. Molecular Operating Environment software was used for the molecular docking experiments. Compared to ascorbic acid, DPPH assay showed that compound 3 had the highest antioxidant activity among the tested compounds with approximately 35% scavenging activity. On ALDH enzymes, compound 3 showed a significant ALDH activity inhibition compared to compound 2 at 200 µM. The IC50 values for the tested compounds were approximately 100 µM on A549 cell line, a non-small cell lung cancer (NSCLC) cell line. However, significant enhancement of cytotoxicity and reduction of IC50 values were observed by combining DOX and synergism was achieved with LVX with a combination index value of 0.4. The molecular docking test showed a minimum binding energy with a good affinity for compound 3 towards ALDH enzymes. Thionated LVX derivatives, may be repurposed for NSCLC therapy in combination with DOX, taking into account the antioxidant activity, ALDH activity inhibition, and the molecular docking results of compound 3.

Abstract 551: Investigation of the antipoliferative effect of the Xylopia Aethiopicaextract in triple-negative breast cancer cells

Abstract Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and has very limited treatment options. Xylopia Aethiopica (XA) is a common spice that is widely used in the regions of central and western Africa. It is known to have various pharmacological properties, one of which is anti-inflammatory activity. The anti-inflammatory effect may portend antiproliferative activity. We hypothesized that the extract of XA will exert antiproliferative activity against TNBC cells. The study aimed to establish the molecular mechanism underlying the antiproliferative activity of XA extract (XAE) against TNBC. The dried fruits of XA were crushed in a mixer and macerated using diethyl ether for 72 h. The macerate was subjected to vacuum and rotary evaporation to remove the organic solvent, and a stock solution was prepared in dimethyl sulfoxide (DMSO). Assessment of the efficacy of XAE was performed using serial dilutions (100 µg/ml, 50 µg/ml, 10 µg/ml, 5 µg/ml, and 1µg/ml) of the XAE stock solution, followed by in vitro testing against two TNBC cell lines (MDA-MB-231, and MDA-MB-468 cells). The cytotoxic effect of the XAE was then measured using the resazurin dye assay. XAE resulted in a concentration-dependent cell death in both cell lines. At the highest concentration (100 µg/ml), XAE induced cytotoxic cell death of 89% and 91% in MDAMB231 and MDAMB468 cells, respectively. This was consistent with IC50 values of 32.95 ± 1.32 µg/ml (MDAMB231) and 20.83 ± 1.05 µg/ml (MDAMB468). At the molecular level, western blot analysis of mitogenic markers associated with MAPK oncogenic signaling pathway demonstrated the inhibition of EGFR and AKT protein levels after a 48-h treatment. Acridine orange-ethidium bromide (AO/EB) staining showed a concentration-dependent induction of apoptosis in both cell lines. Flow cytometric analysis was performed to quantify the apoptotic cells. A significant increase of apoptotic cells was observed in treatment groups as compared to control after 72 h. Apoptotic induction was associated with increased p53 protein levels after 48 h treatment compared to control. The study results underscore the anticancer effects of XAE in TNBC cells mediated through induction of apoptosis. Citation Format: Shailvi Soni, Shail Rakesh Modi, Terrick Andey. Investigation of the antipoliferative effect of the Xylopia Aethiopicaextract in triple-negative breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 551.

In vitro activity of the anthelmintic drug niclosamide against Sporothrix spp. strains with distinct genetic and antifungal susceptibility backgrounds.

The drugs available to treat sporotrichosis, an important yet neglected fungal infection, are limited. Some Sporothrix spp. strains present reduced susceptibility to these antifungals. Furthermore, some patients may not be indicated to use these drugs, while others may not respond to the therapy. The anthelmintic drug niclosamide is fungicidal against the Sporothrix brasiliensis type strain. This study aimed to evaluate whether niclosamide also has antifungal activity against Sporothrix globosa, Sporothrix schenckii and other S. brasiliensis strains with distinct genotypes and antifungal susceptibility status. Minimal inhibitory and fungicidal concentrations (MIC and MFC, respectively) were determined using the microdilution method according to the CLSI protocol. The checkerboard method was employed to evaluate niclosamide synergism with drugs used in sporotrichosis treatment. Metabolic activity of the strains under niclosamide treatment was evaluated using the resazurin dye. Niclosamide was active against all S. brasiliensis strains (n = 17), but it was ineffective (MIC > 20µM) for some strains (n = 4) of other pathogenic Sporothrix species. Niclosamide MIC values for Sporothrix spp. were similar for mycelial and yeast-like forms of the strains (P = 0.6604). Niclosamide was fungicidal (MFC/MIC ratio ≤ 2) for most strains studied (89%). Niclosamide activity against S. brasiliensis is independent of the fungal genotype or non-wild-type phenotypes for amphotericin B, itraconazole, or terbinafine. These antifungal drugs presented indifferent interactions with niclosamide. Niclosamide has demonstrated potential for repurposing as a treatment for sporotrichosis, particularly in S. brasiliensis cases, instigating in vivo studies to validate the in vitro findings.

In vitro antimicrobial and antioxidant potential of Dodonaea viscosa Plant extracts against selected pathogenic isolates

Medicinal plants can be used in the development of new drugs in addition to serving as an indigenous source of new compounds with beneficial effects. The medicinal plants and their parts constitute an important wealth. They play a significant role in healthcare services. The main objective of the study was to investigate the antimicrobial activity, antioxidant activity and phytochemical analysis of Dodonaea viscosa Jacq. Extraction was carried out by cold percolation method. The antimicrobial activity and minimum inhibitory concentration of plant extracts was determined by agar well diffusion and resazurin dye method against various pathogenic isolates. Antioxidant activity of most effective extract was measured by DPPH and hydrogen peroxide method. Among all the extracts, acetone extract of D. viscosa showed highest activity against B. cereus (24.12±0.94 mm at 40 μl) followed by S. aureus (18.78±0.59 mm) and S. flexneri (17.50±0.50 mm). The lowest concentration required to inhibit the growth of B. cereus was 0.1562 mg/100μl. Phytochemical analysis of most effective acetone extract of D. viscosa revealed the presence of alkaloids, flavonoids, phenols, terpenoids, glycosides and saponins. D. viscosa acetone extract showed highest DPPH scavenging activity i.e. 80.81±0.24% at a concentration of 300 μg/ml of plant extract. The results indicated that the crude extracts of D. viscosa have a effective antimicrobial potential that provide a source for development of new drug which may be used for the medicinal purposes. Further studies are required to purify the responsible biochemical constituents of important plant materials and also to characterize so as to explore their potential fully.

A biosensor for D-2-hydroxyglutarate in frozen sections and intraoperative assessment of IDH mutation status

The oncometabolite D-2-hydroxyglutarate (D-2-HG) has emerged as a valuable biomarker in tumors with isocitrate dehydrogenase (IDH) mutations. Efficient detection methods are required and rapid intraoperative determination of D-2-HG remains a huge challenge. Herein, D-2-HG dehydrogenase from Achromobacter xylosoxidans (AX-D2HGDH) was found to have high substrate specificity. AX-D2HGDH dehydrogenizes D-2-HG and reduces flavin adenine dinucleotide (FAD) bound to the enzyme. Interestingly, the dye resazurin can be taken as another substrate to restore FAD. AX-D2HGDH thus catalyzes a bisubstrate and biproduct reaction: the dehydrogenation of D-2-HG to 2-ketoglutarate and simultaneous reduction of non-fluorescent resazurin to highly fluorescent resorufin. According to steady-state analysis, a ping-pong bi-bi mechanism has been concluded. The Km values for resazurin and D-2-HG were determined as 0.56 μM and 10.93 μM, respectively, suggesting high affinity to both substrates. On the basis, taking AX-D2HGDH and resazurin as recognition and fluorescence transducing element, a D-2-HG biosensor (HGAXR) has been constructed. HGAXR exhibits high sensitivity, accuracy and specificity for D-2-HG in different biological samples. With the aid of HGAXR and the matched low-cost palm-size detecting device, D-2-HG levels in frozen sections of resected brain tumor tissues can be measured in a direct, simple and accurate manner with a fast detection (1–3 min). As the technique of frozen section is familiar to surgeons and pathologists, HGAXR and the portable device can be easily integrated into the current workflow, having potential to provide rapid intraoperative pathology for IDH mutation status and guide decision-making during surgery.

Experimental visualization of mass transfer from a slug bubble during co-current flow in a conventional channel

Process intensification during gas–liquid flows is of paramount importance to optimize the size of the chemical reactors. This paper results from an investigation of the mass transfer visualization in a millimetric tube by using the colorimetric technique. A slug bubble train has been established in a 3.8 mm diameter tube for different gas superficial velocities and a constant liquid superficial velocity resulting in the low capillary number range between 0.0004<Ca<0.0006. Color-inducing dye Resazurin solution interacts with the Oxygen bubble to induce the pink color in the solution which has been captured by a high-speed camera. The liquid slug entrapped between the bubbles has three distinct regions namely, the central stem which has a stagnation point ahead of the bubble, the wall lubrication layer, and an entrapped Taylor vortex between the central stem and wall lubrication layer. Flow visualization results have been correlated with the penetration theory-based mass transfer models.

Radiosensitization of Glioblastoma Using Targeted Inhibition of N-Myristoylation

Treating Glioblastoma remains a major challenge. Radiotherapy has a long-standing role in extending survival, but almost all tumors are expected to recur and be fatal. Historic dose-escalation studies do not yield additional benefit beyond the current 60 Gy dose. Further therapeutic improvement can be gained with radiosensitizers. An undiscovered potential radiosensitization approach may exist in inhibiting the N-myristoylation pathways upregulated in malignant cells. Inhibiting this pathway has been shown to have pleotropic effects including decreasing PARP-1 activity and other cancer-driving pathways that may synergize with radiotherapy. This is a first report in using a targeted N-myristoyltransferase (NMT) inhibitor as a radiosensitizer in glioblastoma. Immortalized glioma cell lines (U87 and U251) and patient-derived de novo (ED501) and post-chemoradiation recurrent (ED512) cell lines were used to a NMT1/2 inhibitor with radiotherapy. Cell surface expression levels for NMT1 and NMT2 were established using immunofluorescence microscopy. In vitro cell viability studies via mitochondrial reduction of resazurin dye and clonogenic assays were done with single fraction 2 & 4 Gy irradiation with 5 days of drug exposure (5-150 nM 3 days prior to irradiation and 2 days post) to account for drug pharmacodynamics. PARP-1 expression by western blot was tested with exposure to drug and/or radiation. Whole exome sequencing and methylation profiling were done to find predictive markers of radiosensitization. Preliminary results show significant radiosensitization effect with a dose enhancement factor ranging from 1.33 to 2.71x higher than radiation alone. The amount of radiosensitization varied per cell line, with U251 and ED512 being more sensitive. The cell line sensitivity was not reliably predicted by the NMT cell surface receptor expression. PARP-1 activity increased with radiotherapy but was inhibited with drug exposure. Exome sequencing showed the radiosensitizing effect correlated with mutations in DNA damage repair and myristoylation pathways. N-myristoylation inhibition appears to be a novel method of radiosensitization for glioblastoma. N-myristoylation affects multiple oncogenic pathways including PARP-1 downregulation, which impedes DNA damage repair and may be what leads to radiosensitization. Future studies are aimed at further predictive markers and in vivo efficacy.

Fabrication of a citrus flavonoid hesperetin-capped gold nanoparticles-reduced graphene oxide nanocomposites (Hes-Au/rGONCs) as a potential therapeutic agent for triple negative breast cancer and bacterial infections

Hesperetin (Hes) is a Citrus Flavonoid, which is confirmed to have extensive therapeutic effects, comprising antimicrobial, antioxidant, anticancer, cardiovascular protection, and so forth. To overcome the poor solubility, here we attempt to synthesize the Hes-mediated gold nanoparticles bio-functionalized in reduced Graphene oxide (Hes-Au/rGONCs) to increase the therapeutic efficacy of Hes. The characterization of synthesized Hes-Au/rGONCs were analysed using UV–vis spectrophotometry, FT-IR, Raman spectroscopy, X-ray diffraction analysis (XRD), XPS, HPLC, SEM, EDX and HR-TEM. The absence of vibrations at 1516 and 1381 cm−1 shows the involvement of hydroxyl groups of phenols and enols in anchoring Au on the surface of rGO. In XRD, the planes at (111), (200), (220) and (311) revealed the face centered cubic (fcc) crystalline structure of gold nanoparticles that were functionalized on rGO nanosheets. Hes-Au/rGONCs synthesised produced a highly negative zeta potential of -36.44 mV due to their stability. The Hes-rGO/Au-NPs were analysed for their surface morphology by SEM. The HR-TEM micrographs exhibited uniform distribution and homogenous spherical shaped AuNPs with an average size of 21.37±5.7 nm on rGO sheets. The bio reduction percentage was calculated as 98.86% by using HPLC. The inhibitory concentration (IC50) of free-Hes and nanocomposites were 157.57 and 38.41 µM, respectively. The Hes-Au/rGONCs possess effective bactericidal activity against gram positive bacterial species than against gram negative bacterial strains. The resazurin dye assay confirms the MIC values of Hes-Au/rGONCs. Hereby, the outcome of these studies suggested that the fabricated Hes-Au/rGONCs have potential biomedical applications.

Planophila laetevirens-Mediated Synthesis of Silver Nanoparticles: Optimization, Characterization, and Anticancer and Antibacterial Potentials.

Algal-mediated synthesis of nanoparticles (NPs) opens the horizon for green and sustainable synthesis of NPs that can be used in many fields, such as medicine and industry. We extracellularly synthesized silver NPs (Ag-NPs) using the novel microalgae Planophila laetevirens under optimized conditions. The isolate was collected from freshwater/soil, purified, morphologically identified, and genetically identified using light, inverted light, scanning electron microscopy, and 18S rRNA sequencing. The phytochemicals in the algal extract were detected by GC-MS. Aqueous biomass extracts and cell-free media were used to reduce silver nitrate to Ag-NPs. To get small, uniformly shaped, and stable Ag-NPs, various abiotic parameters, including precursor concentration, the ratio between the reductant and precursor, temperature, time of temperature exposure, pH, illumination, and incubation time, were controlled during the synthesis of Ag-NPs. B-P@Ag-NPs and S-P@Ag-NPs (Ag-NPs synthesized using biomass and cell-free medium, respectively) were characterized using UV-vis spectroscopy, transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis (EDX) and mapping, Fourier transform infrared (FTIR) spectroscopy, and a zeta sizer. S-P@Ag-NPs had a smaller size (10.8 ± 0.3 nm) than B-P@Ag-NPs (19.0 ± 0.6 nm), while their shapes were uniform quasispherical (S-P@Ag-NPs) and spherical to oval (B-P@Ag-NPs). EDX and mapping analyses demonstrated that Ag was the dominant element in the B-P@Ag-NP and S-P@Ag-NP samples, while FTIR revealed the presence of O-H, C-H, N-H, and C-O groups, indicating that polysaccharides and proteins acted as reductants, while polysaccharides/fatty acids acted as stabilizers during the synthesis of NPs. The hydrodynamic diameters of B-P@Ag-NPs and S-P@Ag-NPs were 37.7 and 28.3 nm, respectively, with negative charges on their surfaces, suggesting their colloidal stability. Anticancer activities against colon cancer (Sw620 and HT-29 cells), breast cancer (MDA-MB231 and MCF-7 cells), and normal human fibroblasts (HFs) were screened using the MTT assay. B-P@Ag-NPs and S-P@Ag-NPs had a greater antiproliferative effect against colon cancer than against breast cancer, with biocompatibility against HFs. The biocidal effects of the B-P@Ag-NPs and S-P@Ag-NPs were evaluated against Escherichia coli, Bacillus cereus, and Bacillus subtilis using agar well diffusion and resazurin dye assays. B-P@Ag-NPs and S-P@Ag-NPs caused higher growth inhibition of Gram-negative bacteria than of Gram-positive bacteria. B-P@Ag-NPs and S-P@Ag-NPs synthesized by P. laetevirens are promising antitumor and biocidal agents.