Browsing by Author "Nikolajeva, Vizma"

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    Anti-Inflammatory, Anti-Bacterial, and Anti-Fungal Activity of Oligomeric Proanthocyanidins and Extracts Obtained from Lignocellulosic Agricultural Waste
    (2023-01-15) Andersone, Anna; Janceva, Sarmite; Lauberte, Līga; Ramata-Stunda, Anna; Nikolajeva, Vizma; Zaharova, Natalija; Rieksts, Gints; Telesheva, Galina; Laboratory of Finished Dosage Forms
    It has now been proven that many pathogens that cause infections and inflammation gradually mutate and become resistant to antibiotics. Chemically synthesized drugs treating inflammation most often only affect symptoms, but side effects could lead to the failure of human organs’ functionality. On the other hand, plant-derived natural compounds have a long-term healing effect. It was shown that sea buckthorn (SBT) twigs are a rich source of biologically active compounds, including oligomeric proanthocyanidins (PACs). This study aimed to assess the anti-pathogenic and anti-inflammatory activity of water/ethanol extracts and PACs obtained from the lignocellulosic biomass of eight SBT cultivars. The anti-pathogenic activity of extracts and PACs was studied against pathogenic bacteria Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Bacillus cereus and fungus Candida albicans in 96-well plates by the two-fold serial broth microdilution method. The anti-bacterial activity of purified PACs was 4 and 10 times higher than for water and water/ethanol extracts, respectively, but the extracts had higher anti-fungal activity. Purified PACs showed the ability to reduce IL-8 and IL-6 secretion from poly-I:C-stimulated peripheral blood mononuclear cells. For the extracts and PACs of SBT cultivar ‘Maria Bruvele’ in the concentration range 0.0313–4.0 mg/mL, no toxic effect was observed.
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    Lignocellulosic Waste Compounds for Pancreatic Lipase Inhibition : Preliminary Extraction by Freon, Obtaining of Proanthocyanidins and Testing on Lipase Activity
    (2023-08) Andersone, Anna; Janceva, Sarmite; Lauberte, Līga; Krasiļņikova, Jeļena; Zaharova, Natalija; Nikolajeva, Vizma; Rieksts, Gints; Telysheva, Galina; Department of Human Physiology and Biochemistry
    The twigs of sea buckthorn, blackcurrant, gooseberries, quince, and grapes were evaluated as a promising source of biologically active compounds—proanthocyanidins (PACs). Sea buckthorn twigs had the highest content of PACs (9.2% on dry biomass). Preliminary pretreatment of biomass with freon R134a did not allow an increase in PACs content in the composition of hydrophilic extract but confirmed the value of freon extract as an antibacterial agent against P. aeruginosa and B. cereus. The content of PACs was used as an indicator for assessment of the influence of hydrophilic extracts on pancreatic lipase activity. Under normal physiological conditions, in the presence of bile, the extract, which contained 42.4% of PACs was more effective compared to the extract which contained 17.5% of PACs. At all concentrations (0.2–40 mg of sample/g of pancreatic lipase), it inhibited lipase activity by 33%. Purified PACs were the most effective in inhibiting lipase activity (by 36%). However, in pathological physiological conditions (without bile), the opposite effect on lipase activity was observed. Thus, PACs and extracts can be used as inhibitors of pancreatic lipase only under normal physiological conditions.
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    Sea Buckthorn (Hippophae rhamnoides) Waste Biomass after Harvesting as a Source of Valuable Biologically Active Compounds with Nutraceutical and Antibacterial Potential
    (2022-03-01) Janceva, Sarmite; Andersone, Anna; Lauberte, Liga; Bikovens, Oskars; Nikolajeva, Vizma; Jashina, Lilija; Zaharova, Natalija; Telysheva, Galina; Senkovs, Maris; Rieksts, Gints; Ramata-Stunda, Anna; Krasiļņikova, Jeļena; Department of Human Physiology and Biochemistry
    For sustainable sea buckthorn (Hippophae rhamnoides) berry production, the task at hand is to find an application for the large amount of biomass waste arising at harvesting. Sea buckthorn (SBT) vegetation is currently poorly studied. The purpose of this research was to assess the composition and potential of SBT twigs as a source of valuable biologically active substances. Water and 50% EtOH extracts of twigs of three Latvian SBT cultivars with a high berry yield and quality, popular for cultivation in many countries (H. rhamnoides ‘Maria Bruvele', ‘Tatiana', ‘Botanicheskaya Lubitelskaya'), were investigated for the first time. The phytochemical composition (UHPLC-ESI-MS/MS analysis) and biological activity of the obtained hydrophilic extracts were determined. The highest yield of polyphenolic compounds and serotonin was observed for ‘Maria Bruvele'. Hydrophilic extracts were investigated for radical scavenging activity (DPPH' test), antibacterial/antifungal activity against five pathogenic bacteria/yeast, cytotoxicity, and the enzymatic activity of alpha-amylase (via in vitro testing), which is extremely important for the treatment of people with underweight, wasting, and malabsorption. The results showed a high potential of sea buckthorn biomass as a source of valuable biologically active compounds for the creation of preparations for the food industry, nutraceuticals, and cosmetics.