Browsing by Author "Brangule, Agnese"

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    Antibacterial Activity of Tanacetum vulgare L. Extracts against Clinical Isolates of Bovine Mastitis
    (2023-03) Šukele, Renāte; Bārzdiņa, Ance; Koka, Rudīte; Skadins, Ingus; Lauberte, Līga; Brangule, Agnese; Kovalcuka, Liga; Bandere, Dace; Department of Pharmaceutical Chemistry; Red Cross Medical College of Rīga Stradiņš University; Department of Biology and Microbiology; Laboratory of Finished Dosage Forms
    A bovine mastitis is an infectious disease, which is usually treated with antibiotics. Alternatively, herbal medicine has been proposed due to bacterial resistance. The aim of this study was to determine the antibacterial activity of the acetonic and ethanolic extracts of dried flowers and leaves of Tanacetum vulgare L. against bovine mastitis-inducing clinical isolates such as Escherichia coli, Streptococcus agalactiae, Streptococcus uberis, Serratia liquefaciens, Staphylococcus aureus, and reference cultures of S. aureus and E. coli. The extracts of T. vulgare showed partial antibacterial activity against tested strains of S. aureus. The MIC and MBC values of a 70% ethanol extract of flowers (MIC = 3.4 mg/mL, MBC = 3.4–6.8 mg/mL) were lower than for the 70% ethanol extract of leaves (MIC = 15.7–31.4 mg/mL, MBC = 62.9–125.9 mg/mL). The flower extracts showed low activity against E. coli (MIC = 53.9 mg/mL, MBC = 53.9–107.8 mg/mL) and S. agalactiae (MIC, MBC = 53.9 mg/mL). T. vulgare leaf extracts had minimal antibacterial effects against Streptococcus strains (MIC = 31.4–62.9 mg/mL, MBC = 53.9–125.9 mg/mL) and Serratia liquefaciens (MIC, MBC = 125.9 mg/mL). However, flower extracts had a higher phenolic content that did not correlate with antibacterial effects. T. vulgare flower and leaf extracts could be combined to obtain broader antibacterial effects.
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    Antimicrobial and Antibiofilm Properties of Latvian Honey against Causative Agents of Wound Infections
    (2023-04-26) Skadiņš, Ingus; Labsvārds, Krišs Dāvids; Grava, Andra; Amirian, Jhaleh; Tomsone, Laura Elīna; Ruško, Jānis; Viksna, Arturs; Bandere, Dace; Brangule, Agnese; Department of Biology and Microbiology; Department of Pharmaceutical Chemistry
    Honey is widely used in traditional medicine and modern wound healing biomaterial research as a broad-spectrum antimicrobial, anti-inflammatory and antioxidant agent. The study’s objectives were to evaluate the antibacterial activity and polyphenolic profiles of 40 monofloral honey samples collected from beekeepers in the territory of Latvia. The antimicrobial and antifungal activity of Latvian honey samples were compared with commercial Manuka honey and the honey analogue sugar solutions–carbohydrate mixture and tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, clinical isolates Extended-Spectrum Beta-Lactamases produced Escherichia coli, Methicillin-resistant Staphylococcus aureus and Candida albicans. Antimicrobial activity was evaluated with the well-diffusion method (80% honey solution w/v) and microdilution method. The honey samples with the highest antimicrobial potential were tested to prevent biofilm development and activity against a preformed biofilm. The principal component analysis of the antimicrobial properties of honey samples vs. polyphenolic profile was performed. Eleven honey samples exhibited antibacterial activity to all investigated bacteria. The antibacterial effect of the samples was most significant on the Gram-positive bacteria compared to the studied Gram-negative bacteria. Latvian honey presents promising potential for use in wound healing biomaterials, opening the possibility of achieving long-term antibacterial effects.
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    Cantilever-enhanced photoacoustic spectroscopy applied in the research of natural and synthetic calcium phosphate
    (2017-04-21) Brangule, Agnese; Gross, K. A.; Stepanova, V.; Department of Human Physiology and Biochemistry
    This study demonstrates the significant potential of cantilever-enhanced Fourier transform infrared photoacoustic spectroscopy (FTIR PAS) principles. The improved sensitivity and reproducibility of this method presents a potent tool in the study of biomaterials. The article discusses aspects of the application of cantilever-enhanced FTIR PAS in the research of natural and biological calcium phosphate and the statistical evaluation of the FTIR PAS sampling method. The improved constructions of the FTIR PAS accessory reduce limitations of the conventional capacitive microphone and provide a sensitive tool for samples or processes unreachable by more traditional transmittance methods, or ATR sampling technique. The most common and important applications have been discussed in-depth to show the wide range of problems solved by FTIR PAS.
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    Chemical Profiling and Antioxidant Activity of Tanacetum vulgare L. Wild-Growing in Latvia
    (2023-05) Šukele, Renāte; Lauberte, Liga; Kovalcuka, Liga; Logviss, Konstantins; Bārzdiņa, Ance; Brangule, Agnese; Horváth, Zoltán Márk; Bandere, Dace; Department of Pharmaceutical Chemistry; Red Cross Medical College of Rīga Stradiņš University; Laboratory of Finished Dosage Forms
    The Tanacetum vulgare L. (Tansy) has several ethnobotanical uses, mostly related to the essential oil and sesquiterpene lactones, whereas information regarding other compounds is scarce. This research is designed to characterize the phenolic compounds (flavonoids, phenolic acids, and tannins) to analyze the thujone (which is toxic in high concentrations) content and to detect the antioxidant activity (DPPH assay) of extracts. The main highlights of our work provide a chemical profile of phenolic compounds of T. vulgare harvested from different regions of Latvia, as well as simultaneously support the ethnomedicinal uses for wild T. vulgare through the integration of phenolic compounds as one of the value constituents of leaves and flowers. The extraction yield was 18 to 20% for leaves and 8 to 16% for flowers. The total phenol content in the extracts of T. vulgare as well as their antioxidant activity was different between collection regions and the aerial parts ranging from 134 to 218 mg GAE/g and 32 to 182 mg L−1, respectively. A remarkable variation in the thujone (α + β) content (0.4% up to 6%) was detected in the extracts. T. vulgare leaf extracts were rich in tannins (up to 19%). According to the parameters detected, the extracts of T. vulgare could be considered promising for the development of new herbal products.
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    A Compiled Update on Nutrition, Phytochemicals, Processing Effects, Analytical Testing and Health Effects of Chenopodium album : A Non-Conventional Edible Plant (NCEP)
    (2023-07) Singh, Sukhwinder; Singh, Amandeep; Hallan, Supandeep Singh; Brangule, Agnese; Kumar, Bhupinder; Bhatia, Rohit; Department of Pharmaceutical Chemistry
    Bathua (Chenopodium album) is a rich source of extensive-ranging nutrients, including bio-active carbohydrates, flavonoids and phenolics, minerals, and vitamins that translate to countless health benefits such as anticancer, antidiabetic, anti-inflammatory, antimicrobial, and antioxidant activity. Ascaridole, an important phytoconstituent present in aerial parts of the plant, contributes to its anthelmintic property. Even with vast historical use and significant health benefits, its renown has not spread, and utilization has significantly decreased in recent decades. Gradually, the plant has become known under the name of Non-conventional edible plant (NCEP). This compilation is prepared to bring out the plant under the spotlight for further research by foregrounding previous studies on the plant. Scientific research databases, including PubMed, Google Scholar, Scopus, SpringerLink, ScienceDirect, and Wiley Online, were used to fetch data on C. album. This review offers over up-to-date knowledge on nutritious values, phytochemical composition, volatile compounds, as well as health benefits of C. album. The ethnobotanical and ethnomedicinal uses of the plant in India and other parts of the world are deliberately discussed. Scrutinizing the reported literature on C. album reveals its powerful nutrient composition advantageous in the development of food products. The impact of various cooking and processing methods on the nutritional profile and bioavailability are discussed. The future perspectives with regards to the potential for food and nutraceutical products are critically addressed. This review proves the necessity of breakthrough research to investigate the pharmacology and safety of phytochemicals and nutraceutical development studies on the C. album.
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    Data Booklet for Medical Chemistry
    (Rīga Stradiņš University, 2020) Haļitovs, Mihails; Rikmanis, Ilmārs; Brangule, Agnese; Department of Human Physiology and Biochemistry
    Data booklet for medical chemistry.
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    Development of Composite Sponge Scaffolds Based on Carrageenan (CRG) and Cerium Oxide Nanoparticles (CeO2 NPs) for Hemostatic Applications
    (2023-09-04) Kimia, Alizadeh; Dezvare, Yasaman; Kamyab, Shirin; Amirian , Jhaleh; Brangule, Agnese; Bandere, Dace; Department of Pharmaceutical Chemistry
    In this study, a novel absorbable hemostatic agent was developed using carrageenan (CRG) as a natural polymer and cerium oxide nanoparticles (CeO2 NPs). CRG-CeO2-0.5 and CRG-CeO2-1 composites were prepared by compositing CeO2 to CRG + CeO2 at a weight ratio of 0.5:100 and 1:100, respectively. The physicochemical and structural properties of these compounds were studied and compared with pristine CRG. Upon incorporation of CeO2 nanoparticles into the CRG matrix, significant reductions in hydrogel degradation were observed. In addition, it was noted that CRG-CeO2 exhibited better antibacterial and hemostatic properties than CRG hydrogel without CeO2 NPs. The biocompatibility of the materials was tested using the NIH 3T3 cell line, and all samples were found to be nontoxic. Particularly, CRG-CeO2-1 demonstrated superior hemostatic effects, biocompatibility, and a lower degradation rate since more CeO2 NPs were present in the CRG matrix. Therefore, CRG-CeO2-1 has the potential to be used as a hemostatic agent and wound dressing.
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    From Polymeric Nanoformulations to Polyphenols - Strategies for Enhancing the Efficacy and Drug Delivery of Gentamicin
    (2024-04) Bārzdiņa, Ance; Plotniece, Aiva; Sobolev, Arkadij; Pajuste, Karlis; Bandere, Dace; Brangule, Agnese; Department of Pharmaceutical Chemistry
    Gentamicin is an essential broad-spectrum aminoglycoside antibiotic that is used in over 40 clinical conditions and has shown activity against a wide range of nosocomial, biofilm-forming, multi-drug resistant bacteria. Nevertheless, the low cellular penetration and serious side effects of gentamicin, as well as the fear of the development of antibacterial resistance, has led to a search for ways to circumvent these obstacles. This review provides an overview of the chemical and pharmacological properties of gentamicin and offers six different strategies (the isolation of specific types of gentamicin, encapsulation in polymeric nanoparticles, hydrophobization of the gentamicin molecule, and combinations of gentamicin with other antibiotics, polyphenols, and natural products) that aim to enhance the drug delivery and antibacterial activity of gentamicin. In addition, factors influencing the synthesis of gentamicin-loaded polymeric (poly (lactic-co-glycolic acid) (PLGA) and chitosan) nanoparticles and the methods used in drug release studies are discussed. Potential research directions and future perspectives for gentamicin-loaded drug delivery systems are given.
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    Importance of FTIR spectra deconvolution for the analysis of amorphous calcium phosphates
    (2015) Brangule, Agnese; Gross, Karlis Agris; Rīga Stradiņš University
    This work will consider Fourier transform infrared spectroscopy-diffuse reflectance infrared reflection (FTIR-DRIFT) for collecting the spectra and deconvolution to identify changes in bonding as a means of more powerful detection. Spectra were recorded from amorphous calcium phosphate synthesized by wet precipitation, and from bone. FTIR-DRIFT was used to study the chemical environments of PO4, CO3 and amide. Deconvolution of spectra separated overlapping bands in the 4PO4, 2CO3, 3CO3 and amide region allowing a more detailed analysis of changes at the atomic level. Amorphous calcium phosphate dried at 80 oC, despite showing an X-ray diffraction amorphous structure, displayed carbonate in positions resembling a carbonated hydroxyapatite. Additional peaks were designated as A1 type, A2 type or B type. Deconvolution allowed the separation of CO3 positions in bone from amide peaks. FTIR-DRIFT spectrometry in combination with deconvolution offers an advanced tool for qualitative and quantitative determination of CO3, PO4 and HPO4 and shows promise to measure the degree of order.
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    Lipid-Based Nano-Sized Cargos as a Promising Strategy in Bone Complications : A Review
    (2022-04-01) Hallan, Supandeep Singh; Amirian, Jhaleh; Brangule, Agnese; Bandere, Dace; Department of Pharmaceutical Chemistry
    Bone metastasis has been considered the fatal phase of cancers, which remains incurable and to be a challenge due to the non-availability of the ideal treatment strategy. Unlike bone cancer, bone metastasis involves the spreading of the tumor cells to the bones from different origins. Bone metastasis generally originates from breast and prostate cancers. The possibility of bone metastasis is highly attributable to its physiological milieu susceptible to tumor growth. The treatment of bone-related diseases has multiple complications, including bone breakage, reduced quality of life, spinal cord or nerve compression, and pain. However, anticancer active agents have failed to maintain desired therapeutic concentrations at the target site; hence, uptake of the drug takes place at a non-target site responsible for the toxicity at the cellular level. Interestingly, lipid-based drug delivery systems have become the center of interest for researchers, thanks to their biocompatible and biomimetic nature. These systems possess a great potential to improve precise bone targeting without affecting healthy tissues. The lipid nano-sized systems are not only limited to delivering active agents but also genes/peptide sequences/siRNA, bisphosphonates, etc. Additionally, lipid coating of inorganic nanomaterials such as calcium phosphate is an effective approach against uncontrollable rapid precipitation resulting in reduced colloidal stability and dispersity. This review summarizes the numerous aspects, including development, design, possible applications, challenges, and future perspective of lipid nano-transporters, namely liposomes, exosomes, solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and lipid nanoparticulate gels to treat bone metastasis and induce bone regeneration. Additionally, the economic suitability of these systems has been discussed and different alternatives have been discussed. All in all, through this review we will try to understand how far nanomedicine is from clinical and industrial applications in bone metastasis.
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    A novel one-pot synthesis and characterization of silk fibroin/α-calcium sulfate hemihydrate for bone regeneration
    (2021-06-18) Pandey, Aditi; Yang, Tzu Sen; Cheng, Shu Lien; Huang, Ching Shuan; Brangule, Agnese; Kareiva, Aivaras; Yang, Jen Chang; Department of Pharmaceutical Chemistry
    This study aims to fabricate silk fibroin/calcium sulfate (SF/CS) composites by one-pot synthesis for bone regeneration applications. The SF was harvested from degummed silkworm cocoons, dissolved in a solvent system comprising of calcium chloride:ethanol:water (1:2:8), and then mixed with a stoichiometric amount of sodium sulfate to prepare various SF/CS composites. The crystal pattern, glass transition temperature, and chemical composition of SF/CS samples were analyzed by XRD, DSC, and FTIR, respectively. These characterizations revealed the successful synthesis of pure calcium sulfate dihydrate (CSD) and calcium sulfate hemihydrate (CSH) when it was combined with SF. The thermal analysis through DSC indicated molecular-level interaction between the SF and CS. The FTIR deconvolution spectra demonstrated an increment in the β-sheet content by increasing CS content in the composites. The investigation into the morphology of the composites using SEM revealed the formation of plate-like dihydrate in the pure CS sample, while rod-like structures of α-CSH surrounded by SF in the composites were observed. The compressive strength of the hydrated 10 and 20% SF-incorporated CSH composites portrayed more than a twofold enhancement (statistically significant) in comparison to that of the pure CS samples. Reduced compressive strength was observed upon further increasing the SF content, possibly due to SF agglomeration that restricted its uniform distribution. Therefore, the one-pot synthesized SF/CS composites demonstrated suitable chemical, thermal, and morphological properties. However, additional biological analysis of its potential use as bone substitutes is required.
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    A novel sol-gel Bi2-xHfxO3+x/2 radiopacifier for mineral trioxide aggregates (MTA) as dental filling materials
    (2021-08-02) Yang, Tzu Sen; Chen, May Show; Huang, Cheng Jyun; Chen, Chin Yi; Brangule, Agnese; Zarkov, Aleksej; Kareiva, Aivaras; Lin, Chung Kwei; Yang, Jen Chang; Department of Pharmaceutical Chemistry
    Mineral trioxide aggregate (MTA) is well known as an effective root canal filling material for endodontics therapy. Within MTA, bismuth oxide (Bi2O3) serving as the radiopacifier still has biocompatibility concerns due to its mild cytotoxicity. In the present study, we tried to modify the Bi2O3 radiopacifier by doping hafnium ions via the sol-gel process and investigated the effects of different doping ratios (Bi2-xHfxO3+x/2, x = 0–0.3) and calcination temperatures (400–800 °C). We mixed various precursor mixtures of bismuth nitrate (Bi(NO3)3·5H2O) and hafnium sulfate (Hf(SO4)2) and controlled the calcination temperatures. The as-prepared Hf-doped Bi2O3 radiopaci-fier powders were investigated by thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Portland cement/radiopacifier/calcium sulfate (75/20/5) were mixed and set by deionized water (powder to water ratio = 3:1). Changes in radiopacity, diametral tensile strength (DTS), and in vitro cell viability of the hydrated MTA-like cement were carried out. The experimental results showed that the group containing radiopacifier from sol-gelled Bi/Hf (90/10) exhibited significantly higher radiopacity (6.36 ± 0.34 mmAl), DTS (2.54 ± 0.29 MPa), and cell viability (84.0±8.1%) (p < 0.05) when compared to that of Bi/Hf (100/0) powders. It is suggested that the formation of β-Bi7.78Hf0.22O12.11 phase with hafnium addition and calcining at 700 °C can prepare novel bismuth/haf-nium composite powder that can be used as an alternative radiopacifier for root canal filling mate-rials.
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    The Potential Use of Herbal Fingerprints by Means of HPLC and TLC for Characterization and Identification of Herbal Extracts and the Distinction of Latvian Native Medicinal Plants
    (2022-04-01) Bārzdiņa, Ance; Paulausks, Artūrs; Bandere, Dace; Brangule, Agnese; Department of Pharmaceutical Chemistry
    The growing market of herbal medicines, the increase in international trade in Latvia, and the lack of adequate analytical methods have raised the question of the potential use of herbal fingerprinting methods. In this study, high-performance liquid chromatography (HPLC) and thin layer chromatography (TLC) methods were developed for obtaining chromatographic fingerprints of four taxonomically and evolutionary different medicinal plants ( Hibiscus sabdariffa L., Calendula officinalis L., Matricaria recutita L., Achillea millefolium L.). Retention time shifting, principal component analysis (PCA), hierarchical cluster analysis (HCA), and orthogonal projections to latent structures (OPLS) analysis were used to improve and analyze the obtained fingerprints. HPLC data detection at 270 nm was determined superior to 360 nm for the distinction of medicinal plants and used data alignment method significantly increased similarity between samples. Analyzed medicinal plant extracts formed separate, compact clusters in PCA, and the results of HCA correlated with the evolutionary relationships of the analyzed medicinal plants. Herbal fingerprinting using chromatographic analysis coupled with multivariate analysis has a great potential for the identification of medicinal plants as well as for the distinction of Latvian native medicinal plants.
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    The Processing and Electrical Properties of Isotactic Polypropylene/Copper Nanowire Composites
    (2022-08-18) Lu, Po-Wen; Jaihao, Chonlachat; Pan, Li-Chern; Tsai, Po-Wei; Huang, Ching-Shuan; Brangule, Agnese; Zarkov, Aleksej; Kareiva, Aivaras; Wang, Hsin-Ta; Yang, Jen-Chang; Department of Pharmaceutical Chemistry
    Polypropylene (PP), a promising engineering thermoplastic, possesses the advantages of light weight, chemical resistance, and flexible processability, yet preserving insulative properties. For the rising demand for cost-effective electronic devices and system hardware protections, these applications require the proper conductive properties of PP, which can be easily modified. This study investigates the thermal and electrical properties of isotactic polypropylene/copper nanowires (i-PP/CuNWs). The CuNWs were harvested by chemical reduction of CuCl 2 using a reducing agent of glucose, capping agent of hexadecylamine (HDA), and surfactant of PEG-7 glyceryl cocoate. Their morphology, light absorbance, and solution homogeneity were investigated by SEM, UV-visible spectrophotometry, and optical microscopy. The averaged diameters and the length of the CuNWs were 66.4 ± 16.1 nm and 32.4 ± 11.8 µm, respectively. The estimated aspect ratio (L/D, length-to-diameter) was 488 ± 215 which can be recognized as 1-D nanomaterials. Conductive i-PP/CuNWs composites were prepared by solution blending using p-xylene, then melt blending. The thermal analysis and morphology of CuNWs were characterized by DSC, polarized optical microscopy (POM), and SEM, respectively. The melting temperature decreased, but the crystallization temperature increasing of i-PP/CuNWs composites were observed when increasing the content of CuNWs by the melt blending process. The WAXD data reveal the coexistence of Cu 2O and Cu in melt-blended i-PP/CuNWs composites. The fit of the electrical volume resistivity (ρ) with the modified power law equation: ρ = ρ o (V - Vc) -t based on the percolation theory was used to find the percolation concentration. A low percolation threshold value of 0.237 vol% and high critical exponent t of 2.96 for i-PP/CuNWs composites were obtained. The volume resistivity for i-PP/CuNWs composite was 1.57 × 10 7 Ω-cm at 1 vol% of CuNWs as a potential candidate for future conductive materials.
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    Versatile Potential of Photo-Cross-Linkable Silk Fibroin : Roadmap from Chemical Processing Toward Regenerative Medicine and Biofabrication Applications
    (2023-07-10) Amirian, Jhaleh; Wychowaniec, Jacek K; Amel Zendehdel, Ehsan; Sharma, Gaurav; Brangule, Agnese; Bandere, Dace; Department of Pharmaceutical Chemistry
    Over the past two decades, hydrogels have come to the forefront of tissue engineering and regenerative medicine due to their biocompatibility, tunable degradation and low immunogenicity. Due to their porosity and polymeric network built up, it is possible to incorporate inside drugs, bioactive molecules, or other biochemically active monomers. Among biopolymers used for the fabrication of functional hydrogels, silk fibroin (SF) has received considerable research attention owing to its known biocompatibility and tunable range of mechanical properties. However, its relatively simple structure limits the potential usability. One of the emerging strategies is a chemical functionalization of SF, allowing for the introduction of methacrylate groups. This allows the versatile processing capability, including photo-cross-linking, which makes SF a useful polymer as a bioink for 3D printing. The methacrylation reaction has been done using numerous monomers such as methacrylic anhydride (MA), 2-isocyanatoethyl methacrylate (IEM), or glycidyl methacrylate (GMA). In this Review, we summarize the chemical functionalization strategies of SF materials and their resulting physicochemical properties. More specifically, a brief explanation of the different functionalization methods, the cross-linking principles, possibilities, and limitations of methacrylate compound functionalization are provided. In addition, we describe types of functional SF hydrogels and link their design principles to the performance in applications in the broad fields of biofabrication, tissue engineering, and regenerative medicine. We anticipate that the provided guidelines will contribute to the future development of SF hydrogels and their composites by providing the rational design of new mechanisms linked to the successful realization of targeted biomedical application.