Beta vulgaris Assisted Fabrication of Novel Ag-Cu Bimetallic Nanoparticles for Growth Inhibition and Virulence in Candida albicans

Beta vulgaris extract contains water-soluble red pigment betanin and is used as a food colorant. In this study, the biogenic Ag-Cu bimetallic nanoparticles were synthesized and characterized by different spectroscopic and microscopic techniques, including UV–Visible, FTIR, TEM. SEM-EDX, XRD, and TGA. Further, Ag-Cu bimetallic nanoparticles capped with Beta vulgaris biomolecules were evaluated for their antifungal activity against Candida albicans via targeting its major virulence factors, including adherence, yeast to hyphae transition, extracellular enzyme secretion, biofilm formation, and the expression of genes related to these pathogenic traits by using standard methods. C. albicans is an opportunistic human fungal pathogen that causes significant morbidity and mortality, mainly in immunocompromised patients. The current antifungal therapy is limited with various shortcomings such as host toxicity and developing multidrug resistance. Therefore, the development of novel antifungal agents is urgently required. Furthermore, NPs were screened for cell viability and cytotoxicity effect. Antifungal susceptibility testing showed potent antifungal activity of the Ag-Cu bimetallic NPs with a significant inhibitory effect on adherence, yeast to hyphae transition, extracellular enzymes secretion, and formation of biofilms in C. albicans at sub-inhibitory and inhibitory concentrations. The RT-qPCR results at an MIC value of the NPs exhibited a varying degree of downregulation in expression levels of virulence genes. Results also revealed the dose-dependent effect of NPs on cellular viability (up to 100%) using MUSE cell analyzer. Moreover, the low cytotoxicity effect of bimetallic NPs has been observed using haemolytic assay. The overall results indicated that the newly synthesized Ag-Cu bimetallic NPs capped with Beta vulgaris are proven to possess a potent anticandidal activity, by affecting the vital pathogenic factors of C. albicans.

Screening of Biosurfactant Producing Bacteria Isolated from Hydrocarbon Contaminated Site and Their Potential in Biosorption of Pb(II) and Oil Biodegradation

In the present study, three potentially Pb(II)-resistant and biosurfactant-producing bacterial strains were isolated from a total of 23 strains using various screening methods, investigated for their biosorption of Pb(II) and used for the biodegradation of used motor oil. The results show that strain E1 (Bacillus haynesii) has significantly high efficiency in biodegradation of used motor oil, up to 82 % in the first three days. Maximum Pb(II) biosorption capacities of 238.09 mg/g and 99.01 mg/g were determined for strains E1 and F5 (Pseudomonas aeruginosa), respectively. The biosorption process was found to be in good agreement with the Langmuir isotherm for both E1 (R2 = 0.9614) and F5 (R2 = 0.9646), suggesting monolayer biosorption. The four common screening methods, namely the haemolytic assay, the determination of surface tension, the emulsifying activity and the foam test, were also correlated with the Pearson correlation method.

Comparative Toxicity, Biodistribution and Excretion of Ultra-Small Gold Nanoclusters with Different Emission Wavelengths

The exponentially increased use of gold nanoclusters in diagnosis and treatment has raised serious concern about their potential threat to living organisms. However, the mechanisms of toxicity of gold nanoclusters in vitro and in vivo remain poorly understood. In this work, comparative toxicity studies, including biodistribution and excretion, were carried out with mildly and chemically synthesized ultra-small L-histidine-protected and bovine serum albumin (BSA)-protected gold nanoclusters in an all-aqueous process. These nanoclusters did not induce a remarkable impact on cell viability, even at relatively high concentrations (100 μg/mL). The haemolytic assay demonstrated that the gold nanoclusters could not destroy blood cell at 600 μg/mL. After intravenous injection with mice, the biocompatibility, biodistribution, and excretion were determined. Quantitative analysis results showed that accumulation varied in the liver, spleen, kidney, and lung, though primarily in the liver and spleen. They were excreted in urine and faeces, but mainly excreted through urine. In our study, no obvious abnormalities were found in body weight, behavioral changes, blood and serum biochemical indicators, and histopathology. These findings suggested that both gold nanoclusters showed similar effects in vivo and were safe and biocompatible, laying the foundation for safe biomedical application in the future.

Phytochemical Screening and Antidiabetic, Antihyperlipidemic, and Antioxidant Effects of Leptopus Cordifolius Decne. In Diabetic Mice

Plants are well known in traditional herbal medicines for their hypoglycemic and hypolipidemic activities and are often used due to their accessibility, affordability, and corollary effects. Leptopus cordifolius has been reported to control diabetes in folkloric medicine, but no known scientific research has been conducted to assess the plausibility of this assertion. Therefore, the current study is aimed to investigate the antidiabetic and hypolipidemic effects of Leptopus cordifolius leaves in alloxan-induced diabetic mice. The antidiabetic and antihyperlipidemic evaluation was conducted in Swiss albino mice at doses of 150–250°mg/kg for 15°days. The blood glucose, total cholesterol, triglyceride, LDL, HDL, creatinine, ALP, SGPT, and SGOT levels were estimated according to standard procedures. Phytochemicals of leaves were analyzed using GC-MS analysis. Enzymatic antioxidant activity of the plant was investigated spectrophotometrically by carrying out superoxide dismutase, peroxidase, and catalase assays. The membrane stabilization potential of L. cordifolius leaf extracts was carried out using an in vitro haemolytic assay. The results revealed a dose response effect with the methanolic extract of L. cordifolius which had significant antihyperglycemic effects at 150–250°mg/kg in alloxan treated mice, although less than the positive control (glibenclamide). Hyperlipidemic activity was significant at 250 mg/kg. The biochemical parameters, such as total cholesterol, triglyceride, LDL, HDL, creatinine, ALP, SGPT, and SGOT, were significantly improved (p < 0.01) by the methanolic extract of 250 mg/kg compared to the diabetic group. Treatment for 15 days showed significant elevation (p < 0.01) of antioxidant enzymes. GC-MS analysis provided tentative identifications of 52 compounds in the methanolic extract of L. cordifolius, of which 12 compounds have reported antidiabetic activity. In conclusion, methanolic extract of L. cordifolius of 150 and 250°mg/kg body weight showed significant antidiabetic and antihyperlipidemic activities in alloxan-induced diabetic mice and, with further work, has the potential to be used to manage blood glucose and cholesterol levels.

Characterization of therapeutic targets from Aspergillus fumigates in response to Adjunctive Combination therapy (Ketoconazole with EDTA).

Background: The Kingdom (Fungi) comprises numerous species that are associated with numerous fungal diseases. Moreover, the fungal resistance, stagnation in the development of antifungal agents and unacceptably high mortality rate associated with some resistant fungus indicates that alternative therapeutic options should consider. Objective: The objective of this study was to find out new therapeutic targets of A.fumigatus in response to adjunctive combination i.e. Ketoconazole (KTZ) plus EDTA. Methods: A.fumigatus was cultured in absence and presence of sublethal dose (MIC 50) of EDTA, KTZ and Combination of KTZ plus EDTA. The cytosolic proteins were extracted by mechanical grinding of fungal cells.The protein profile was studied by using proteomic approach and identification of protein was done by MALDI-TOF/MS. The morphologicaleffect of combination on A. fumigatus was studied by Scanning Electron Microscopy (SEM) and toxic effect on erythrocytes by haemolytic assay. Result: The combination of KTZ with EDTA was non-toxic upto 500 µg/ml by MTT assay. It inhibits the expression offollowing proteins-Glutamatedehydrogenase, Phenyl alanyl t-RNA synhetase POD G, CaO19-5601, AN6454.2 (Conserved domain; MFS (Major Facilitator Superfamily), serine/threonine protein kinase and dipeptidyl peptidase (identified by peptide mass finger printing).Some of these proteins are involved in hyphal development. Morphological defects on development of fungus (like disrupted hyphal tips,phialide) were observed. Conclusion: These targets can be used for novel drug development as some of them are involved in fungal virulence and adjunctive combination therapy can be an optimistic approach.

Mycosynthesis of biocompatible gold nanoparticles using Penicillium sp for bromothymol blue degradation

Introduction and Aim: The Biosynthesis of Gold nanoparticles (Au NPs) is an eco-friendly, cost effective and nontoxic alternative to chemical and physical methods. In the present study synthesis of Au NPs was performed by using a fungi Penicillium sp. isolated from agriculture soil. Materials and Methods: Fungi was isolated from the agricultural field and inoculated into Sabouraud Dextrose broth and incubated at 28º C in a shaker at 180 rpm for 96 to 120 hours. After incubation, the fungal culture was filtered and centrifuged, obtained fungal cell free extracts treated with 1mM gold salt (HAuCl4). The synthesis of Au NPs was confirmed by UV–visible spectroscopy and particles size was measured using Dynamic Light Scattering (DLS). Haemolytic assay of Au NPs was carried out using Chicken RBCs and results measured at 540 nm in UV-visible spectrophotometer. To study catalytic activity, Bromothymol blue (BB) was subjected to reduction by using sodium borohydride (NaBH4, 5.28X10-2 M) in the presence of Au NPs. Then the color change was monitored by visual observation. Results: The synthesis of Au NPs was preliminary observed by a color change from yellow to purple and confirmed by a peak at 560 nm using a UV–visible spectroscopy. The DLS analysis showed that the Au NPs were poly-dispersed and size ranges from 130 to 150 nm. The biosynthesised Au NPs was studied for their biocompatibility and dye degradation properties. Conclusion: The obtained results revealed that biosynthesized Au NPs shows a minimum level of toxicity to chicken erythrocytes and good catalytic activity towards the degradation of hazardous dye bromothymol blue. These nanoparticles could be potentially useful in various applications in medical and environmental fields.

Modification and Targeted Design of N-Terminal Truncates Derived from Brevinin with Improved Therapeutic Efficacy

Antimicrobial peptides (AMPs) are a class of molecules that play an essential role in innate immune regulation. The Brevinin-1 family are AMPs that show strong pharmacological and antimicrobial potential. A novel peptide, B1A, was designed based on the primary structure of brevinin-1PLb and brevinin-1PLc. Subsequently, a synthesised replicate was subjected to a series of bioassays and was found to display antimicrobial activity. However, it also displayed high levels of haemolysis in a horse red blood cell haemolytic assay, suggesting potential toxicity. Therefore, we rationally designed a number of B1A analogues with aim of retaining antimicrobial activity, lowering toxicity, and to explore the structure–activity relationship of its N-terminus. B1A and its analogues still retained the “Rana Box” and the FLP-motif, which is a feature of this subfamily. However, the introduction of Lys and Trp residues into the peptide sequences revealed that antimicrobial activity of these analogues remained unchanged once the hydrophobicity and the charge reached the threshold. Hence, the idea that the hydrophobicity saturation in different situations is related to antimicrobial activity can be understood via the structure–activity relationship. Meanwhile, it could also be the starting point for the generation of peptides with specific antimicrobial activity.

Biogenic Synthesis of Silver Chloride Nanoparticles from Padina gymnospora and their Evaluation of Antimicrobial, Larvicidal, Hemolytic and Anticancer Activities.

In the current study, silver chloride nanoparticles (AgClNPs) have been synthesized using the aqueous extract of Padina gymnospora and further characterized by Uv-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, Scanning electron microscopy, energy dispersive spectroscopy, Transmission electron microscopy and Atomic force microscopy. The synthesized silver chloride nanoparticles were found to be mono-dispersed and spherical with an average size between 11.5 to 32.86 nm. The particles also showed a cytotoxic effect in a dose-dependent manner against MCF 7 cells (IC50 = 31.37 µg/mL). Besides, it showed the larvicidal activity against Aedes aegypti at a lower dose (3.92 µg/ml) than that of the aqueous extract (13.01 µg/ml). It also exhibited significant antimicrobial activity against selected bacterial and fungal pathogens. The synthesized silver chloride nanoparticles showed the best minimum inhibitory concentration (MIC) of 8 mg/L in Canadian Albicans, followed by vancomycin resistance Enterococcus feacasli (VREF) 32 mg/L. Furthermore, the toxicity assessment by haemolytic assay revealed that AgClNPs could be safe and also used for further investigation. Therefore, the synthesized silver chloride nanoparticles may be used as a therapeutic agent for breast cancer, antimicrobial agent and also to control the dengue vector as attributed to the presence of bioactive components.

Isolation and Molecular Characterization of Biosurfactant-Producing Yeasts from Saps of Elaeis guineensis and Raphia africana

Aim: This study investigated the screening and molecular characterization of biosurfactant-producing yeasts from saps of Elaeis guineensis (oil palm) and Raphia Africana (Raphia palm). Methodology: Physicochemical characteristics (pH, temperature, alcohol contents, and reducing sugars) of the saps of Elaeis guineensis and Raphia africana were determined. The capacity of the yeast isolates from both samples to produce biosurfactant was evaluated using emulsification index (E24), emulsification assay, haemolytic assay, oil displacement test, and tilted glass slide. The yeast isolates were identified based on their phenotypic, microscopic, biochemical, and molecular characteristics. Results: Chemical analysis of the palm wine saps revealed respective pH, temperature, alcohol, and reducing sugars contents of 5.68, 17.1°C, 0.943% and 1.090 mg/mL for Elaeis guineensis and 5.26, 16.9°C, 0.884% and 2.099 mg/mL for Raphia africana. Six isolates (SA-2, SA-5, SB-3, SB-5, SB-6 and SB-8) out of sixteen isolates (16) distributed within both samples were found to produce biosurfactant. Phylogenetic analysis based on the internally transcribed spacer (ITS) genes classified the six isolates as Candida haemulonis SA2, Pichia kudriavzevii SA5, Pichia kudriavzevii SB3, Pichia kudriavzevii SB5, Pichia kudriavzevii SB6, and Pichia kudriavzevii SB8. The sequences obtained from the study have been deposited in GenBank under the accession numbers MN007219.1-MN007224.1. The result obtained from the study revealed high biosurfactant activity with a maximum E24 of 64.5% compared to E24 of 72% by sodium dodecyl sulphate (SDS). Conclusion: The study demonstrated that saps from Elaeis guineensis and Raphia africana were suitable sources of biosurfactant-producing yeasts with high capacity for hydrocarbon emulsification. The main six biosurfactant-producing yeasts were found to belong to the genera Candida and Pichia.

Effect of Cultural Conditions on Biosurfactant Production by Candida sp. Isolated from the Sap of Elaeis guineensis

Aims: This study is aimed at determining the effect of cultural condition on biosurfactant production by Candida sp. isolates from saps of Elaeis guineensis. Methodology: Chemical analysis of the sap was carried out. Yeast isolates from the sap were screened for biosurfactant production based on emulsification index (E24), emulsification assay, haemolytic assay, oil displacement test, CTAB and tilted glass slide ability. The best biosurfactant-producing yeast isolate was identified based on its phenotypic, microscopic, and biochemical characteristics. The emulsification capacity of the produced biosurfactant on selected oils was studied. Optimum cultural and nutritional requirements (temperature, pH, inoculum concentration, nitrogen sources and carbon sources) for biosurfactant production by the isolate were determined. Results: The characteristics of the sap from Elaeis guineensis were reducing sugar (0.51 ± 0.03 mg/ml), alcohol (14.04 ± 0.15%), specific gravity (0.827±0.024), and pH (5.68±0.03). The crude biosurfactant produced displaced a thin film of crude oil on petri dish by 55 mm, and revealed high emulsification index (E24) of 52.5% using Olive oil as substrate compared to E24 of 60.6% by sodium dodecyl sulphate (SDS). Based on colonial, microscopic, and biochemical characteristics, the isolate SA2 was identified as Candida sp. The crude biosurfactant showed varying capacity in emulsifying the different oils that were examined. Optimization data revealed maximum biosurfactant production after 7 days of incubation, inoculum concentration of 10%, at temperature of 20ºC, pH of 2 with cassava peel as substrate. Conclusion: The study has demonstrated the capacity of Candida sp. from the sap of Elaeis guineensis to produce biosurfactant utilizing cassava peel as substrate. The use of cassava peel, which represents a low-cost substrate, is important in reducing the cost of biosurfactant production. Moreover, using yeasts from Elaeis guineensis make the production process ecologically friendly.