Evaluation of chemical composition, antioxidant potential and functional properties of carob (Ceratonia siliqua L.) seeds.

The interest in carob pod as an ingredient of functional foods is constantly increasing due to its beneficial health effect and functional properties. The aim of this study was to evaluate the chemical composition and antioxidant potential of carob seeds, as well as the functional properties of its isolated galactomannan fraction. The lipid, protein, carbohydrate and phenolic composition were analysed. The obtained results demonstrated that the main detected fatty acids were oleic (45.0%), linoleic (32.4%), and palmitic (16.6%) acid. The primary tocopherol in the tested tocopherol fraction was γ-tocopherol (53.1%). It was established that ß-sitosterol (74.2%) and stigmasterol (12.8%) predominated in the sterol fraction. Carob seed was characterized by high protein (25.7%) content, while mannose and galactose were the dominating monosaccharides. Moreover, the isolated galactomannan from carob seed demonstrated good swelling properties-30.1 ml per g sample and oil-holding capacity (27.9 g/g sample). The total polyphenolic and flavonoids content of carob seeds was 1.76 mg Gallic acid equivalent/g dry weight and 0.30 mg quercetin equivalents/g dry weight, respectively. The carob seeds showed the highest antioxidant potential by cupper reduction assay-15.71 mM Trolox® equivalent/g dry weight. The mineral composition was also defined as the macroelements Ca and Mg were the predominant minerals in the seed. The obtained results showed that carob seeds were a valuable source not only of phenolic compounds and antioxidants, but also of proteins, lipids, galactomannan with functional properties that could improve the nutritional value of foods in which are incorporated.

Chemical Composition and Antimicrobial Activity of Laurus nobilis L. Essential Oils from Bulgaria.

Laurel, Laurus nobilis L. is an evergreen plant belonging to the Lauraceae family, native to Southern Europe and the Mediterranean area. This is the first report on the composition and bioactivity of laurel essential oil (EO) from Bulgaria. The oil yield was 0.78%, 0.80%, and 3.25% in the fruits, twigs, and leaves, respectively. The main constituents in the fruit EO were 1,8-cineole (33.3%), α-terpinyl acetate (10.3%), α-pinene (11.0%), ß-elemene (7.5%), sabinene (6.3%), ß-phellandrene (5.2%), bornyl acetate (4.4%), and camphene (4.3%); those in the twig EO were 1,8-cineole (48.5%), α-terpinyl acetate (13.1%), methyl eugenol (6.6%), ß-linalool (3.8%), ß-pinene (3.4%), sabinene (3.3%) and terpinene-4-ol (3.3%); and the ones in the leaf EO were 1,8-cineole (41.0%), α-terpinyl acetate (14.4%), sabinene (8.8%), methyl eugenole (6.0%), ß-linalool (4.9%), and α-terpineol (3.1%). The antibacterial and antifungal properties of laurel EOs were examined according to the agar well diffusion method. The leaf EO showed antibacterial and antifungal activities against almost all strains of the microorganisms tested, whereas the twig EO was only able to inhibit Staphylococcus aureus. Pseudomonas aeruginosa ATCC 9027 and Escherichia coli ATCC 8739 were the bacterial strains that showed the highest resistance to the laurel EO. The results can benefit the EO industry and biopesticide development.

Revealing the effects of amino acid, organic acid, and phytohormones on the germination of tomato seeds under salinity stress.

Salinity accumulation poses a threat to the production and productivity of economically important crops such as tomatoes (Solanum lycopersicum L.). Currently, salt tolerance breeding programs have been limited by insufficient genetic and physiological knowledge of tolerance-related traits and a lack of an efficient selection domain. For that purpose, we aimed to determine the ability of tomato cultivars to tolerate salt based on seed traits by multiple biochemical pathways. First, we tested three tomato cultivars according to their response to different sodium chloride (NaCl) concentrations (0, 6.3, 9.8, 13.0, and 15.8 dS m-1) and then we analysed their amino acids, organic acids, and phytohormones. Considering the results of germination traits, it is possible to conclude that cultivar H-2274 was more tolerant to salt stress than others. As a result, multivariate discriminant analysis including principal component analysis and two-way hierarchical clustering analyses were constructed and demonstrated that tomato cultivars were separated from each other by the amino acid, organic acid, and phytohormone contents. Considering germination traits of tomato seeds, cv. 'H-2274' was more tolerant to salinity than others depending on high proline (29 pmol µl-1) and citric acid (568 ng µl-1) assays. Biochemical variability offers a valuable tool for investigating salt tolerance mechanisms in tomatoes, and it will be appreciated to find high-tolerant tomato cultivar(s) to saline conditions. Also, the findings of this study have significant potential for practical applications in agriculture, particularly in developing salt-tolerant tomato cultivars to enhance productivity in saline environments and address socio-economic challenges.

Strength Characteristics and Rheological Behavior of a High Level of Fly Ash in the Production of Concrete.

This study investigates the valorization of coal fly ash (FA-C) generated by the Jerada thermal power plant, aiming to address the pressing need for sustainable construction practices and reduced greenhouse gas emissions in the concrete industry. It is widely used as a pozzolanic material. The key objective is to harness the potential of FA-C as a supplementary material in concrete production, which not only reduces costs but also contributes to environmental sustainability. To achieve this objective, various concrete mixtures were formulated, with FA-C serving as a partial substitute for cement at percentages ranging from 15 to 50%. According to ASTM standards, compressive strength tests were conducted on standard-sized cylinders at 7 and 28 days. The results revealed that the blend containing 15% FA-C exhibited the highest compressive strength, indicating its effectiveness as a concrete additive. Furthermore, this study delves into the rheological properties of concrete mixes, an essential aspect of successful concrete processing. It was observed that a higher replacement level of FA-C significantly improved the rheology, leading to reduced water demand and a linear decrease in plastic viscosity over time. The rheological parameters stabilized after a certain period, demonstrating the controllability of concrete flow behavior with FA-C. The investigation also employed three analytical methods-Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM)-to comprehensively analyze both raw materials and processed samples. FTIR analysis highlighted the minimal impact of FA particles on hydration product formation, emphasizing the role of FA-C in enhancing the concrete's strength. XRD analysis confirmed the presence of an amorphous phase crucial for FA's reactivity. SEM observations revealed that concrete with 15% FA-C exhibited a more uniform microstructure with aluminosilicate gel, while 50% FA-C mixes showed increased porosity and nonhomogeneity due to unreacted FA particles.

Chemical profile of Juniperus excelsa M. Bieb. essential oil within and between populations and its weed seed suppression effect.

The aims of this study were to (1) establish the intrapopulation and seasonal variation of Juniperus excelsа essential oil (EO); (2) compare the J. excelsa concrete and resinoid composition with its EO composition; and (3) investigate the potential herbicidal activity of J. excelsa EO against seeds of Papaver rhoeas L., Consolida orientalis (J.Gay) Schrödinger, Anthemis arvensis L., Avena fatua L., and Agrostemma githago L. Four independent studies were performed to meet these objectives. Twenty-eight individual trees were analyzed from two populations to establish intrapopulation and interpopulation variability of EOs yield and composition. In the seasonal dynamic study of leaf EO, samples from the same three trees and in the same population were collected in January, March, May, July, October, and December and their EO yield and composition determined. The EOs (intrapopulation and seasonal) were extracted by hydrodistillation, while the EO for the herbicidal test was obtained by steam distillation in a semi-commercial (SCom) apparatus. Overall, the EO yield varied significantly from 0.93% to 2.57%. α-Pinene (8.85-35.94%), limonene (11.81-50.08%), and cedrol (3.41-34.29%) were the predominant EO compounds in all samples (intrapopulation variability); however, trans-2,4-decadienol and ß-caryophyllene were predominant in some individual trees. Four chemical groups were identified in the samples collected from two natural populations (intrapopulation). This is the first report on the compositions of J. excelsa concrete and resinoid. Cedrol (15.39%), 7-hydroxy-4-methyl-coumarin (17.63%), 1-octacosanol (36.85%), tritriacontane (16.08%), and tiacontanoic acid were the main compounds in the concrete and resinoid. Juniperus excelsa EO suppressed seed germination and seedling growth of P. rhoeas, C. orientalis, A. arvensis, A. fatua, and A. githago, demonstrating its potential to be used for the development of new biopesticides. The highest EO yield with high content of limonene and cedrol was obtained from samples harvested during the winter months (December, January, and March).

Exploratory evaluation supported by experimental and modeling approaches of Inula viscosa root extract as a potent corrosion inhibitor for mild steel in a 1 M HCl solution.

The corrosion of metals poses a threat to the economy, the environment, and human health due to undesirable reactions and contaminated products. Corrosion inhibitors, including natural products, can play a key role in protecting metallic materials, especially under challenging conditions. In this study, the roots of the Inula viscosa plant were examined for their ability to act as corrosion inhibitors in a 1 M hydrochloric acid (HCl) solution. Different extracts of the plant were evaluated for their corrosion inhibition capacity in a 1 M HCl solution. The effectiveness of different plant extracts was assessed, including an aqueous extract, an ethanolic extract, and a combined water-ethanol extract. Compounds present in the roots of Inula viscosa were identified using high-performance liquid chromatography. The electrochemical properties of the extracts were studied using various techniques such as open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization. Additionally, surface analysis after immersion was performed using scanning electron microscopy. Electrochemical data revealed that Inula viscosa root (IVR) extracts acted as mixed-type corrosion inhibitors with pronounced cathodic characteristics. The inhibitory efficiency was closely related to the concentration of Inula viscosa (I. viscosa), showing a significant increase with higher concentrations. This resulted in a decrease in corrosion current and an increase in polarization resistance. Notably, inhibitory efficiency reached high levels, up to 97.7% in mixed extract which represents a mixture between water and ethanol. In our study, it was observed that the mixed extract (water + ethanol) allowed for a greater corrosion inhibition compared to the other solvents studied, 97.7%. Surface analyses confirmed the formation of an organic film layer on the steel surface, attributed to the bonding of functional groups and heteroatoms in I. viscosa components. Therefore, this study paves the way for the potential integration of I. viscosa as a promising corrosion inhibition material, offering durable protection against steel corrosion and opening avenues for various related applications.

Comprehensive phytochemical and toxicological analysis of Chenopodium ambrosioides (L.) fractions.

Chenopodium ambrosioides aerial parts have been historically employed in traditional medicine for addressing various ailments such as headaches, abdominal discomfort, joint issues, and respiratory disorders, alongside treatments for lice and warts. This study aimed to conduct a comprehensive phytochemical analysis of C. ambrosioides and assess the acute and subacute toxicity of oral treatments using fractions in preclinical trials. Spectrophotometric analysis via LC-MS/MS was used to characterize the plant's chemical composition. Acute toxicity evaluation followed Organisation for Economic Co-operation and Development code 42 guidelines, conducted on adult male and female Wistar strain mice. Subsequently, Swiss mice were divided into six groups for the subacute toxicity study, receiving oral doses of 200 mg/kg extracts and fractions for 28 days. Daily observations and biochemical analyses were performed, with LC-MS/MS revealing a diverse array of compounds including organic acids, flavonoids, phenolic acids, rutin, hesperidin, nicotiflorine, and fumaric acid. Results indicated no lethality or alterations in body weight in treated groups, though some organ weight changes were noted. Biochemical analyses demonstrated values within the normal range for all groups, suggesting that the treatments did not induce adverse effects. Acute and subacute treatments with fractions did not result in lethality or toxic alterations at therapeutic doses, implying the safety of the product at appropriate levels. This study underscores the potential of C. ambrosioides as a safe therapeutic option warranting further exploration.

Evaluation of the impact of two citrus plants on the variation of Panonychus citri (Acari: Tetranychidae) and beneficial phytoseiid mites.

The abundance of Panonychus citri McGregor 1916 (Acari: Tetranychidae) and its associated enemies (Euseius stipulatus Athias-Henriot, 1960; Typhlodromus sp.; Phytoseiulus persimilis Athias-Henriot, 1957) was studied on two 12-year-old citrus cultivars, specifically Clementine "Nules" (Citrus Clementina) and Valencia (Citrus sinensis), in the Gharb region of Morocco. Throughout the entire monitoring period in the Valencia late cultivar, the density of the spider mite P. citri on leaves was notably higher at 38.0% (n = 1,212 mobile forms). Predator P. persimilis exhibited a leaf occupancy of 25.0% (n = 812), followed by Typhlodromus sp. at 20.0% (n = 643). Conversely, the abundance of E. stipulatus was lower at 17.0% (n = 538). In the Nules variety, P. citri abundance recorded a higher percentage at 48.0% (n = 1,922). E. stipulatus emerged as the most abundant predator at 23.0% (n = 898), followed by P. persimilis with 16.0% (n = 639). Meanwhile, the population of Typlodromus sp. remained notably low at 13.0% (n = 498). Regarding the fluctuation of the different mites studied on the two cultivars across monitoring dates, the period from May 4 to June 1 was characterized by low temperatures and a diminished presence of mite populations (P. citri, E. stipulatus, Typhlodromus sp., and P. persimilis). However, from June 7 to June 19, characterized by high temperatures, a notable increase in the presence of mite populations was observed. As regards the effect of the variety on the different mites studied, the varietal impact was significant.

Impact of Climate Change on the Chemical Compositions and Antioxidant Activity of Mentha pulegium L.

A central position in Moroccan ethnobotany is held by the Mentha genus, serving as a vital reference for aromatic and medicinal plants within the Lamiaceae family. The profound importance of Mentha species in the daily lives of Moroccans is recognized, and the primary objective of this study is to assess the impact of rising temperatures and decreasing precipitation on the primary and secondary metabolites of Mentha pulegium under the following climatic conditions: sample 1, cultivated under standard temperature and precipitation conditions during the first year; sample 2, subjected to an 8 °C temperature increase and a 25% reduction in water supply; and sample 3, exposed to a 12 °C temperature rise and a 50% decrease in water availability. Phytochemical screening results reveal a progressive decline in primary metabolites from sample 1 to sample 3 due to the increase in temperature and decrease in precipitation. Conversely, a distinct trend is observed in secondary metabolites and the yield of essential oil, increasing from sample 1 to sample 2 as the temperature rises and precipitation decreases. Remarkably, in sample 3, the yield of essential oil decreases as climatic conditions further deteriorate. Additionally, GC analysis demonstrates that modifications in the chemical compositions of essential oils occur because of the disruption of climatic parameters, particularly in the major compounds. Similarly, changes in climatic parameters significantly influence antioxidant activity, with sample 2 exhibiting the highest activity, as reflected by an IC50 value (half-maximal inhibitory concentration) of 14,874.04 µg/mL, followed by the third sample at 8488.43 µg/mL, whereas the first sample exhibits the lowest activity at 4505.02 µg/mL. In summary, the complex relationship between climatic factors and the chemical composition of Mentha pulegium is highlighted by our experiment, emphasizing its implications for medicinal properties within an ecological context.

Chemical Composition of Essential Oils from Nepeta transcaucasica Grossh. and Nepeta cataria L. Cultivated in Bulgaria and Their Antimicrobial and Antioxidant Activity.

The genus Nepeta, belonging to the family Lamiaceae, includes about 300 species, most of which are used in folk medicine due to their pronounced biological properties. The aim of the present study was to evaluate the agrobiological characteristics of Nepeta transcaucasica (N. transcaucasica) Grossh. and Nepeta cataria (N. cataria) L., cultivated in Bulgaria, and obtain their essential oils and determine their antimicrobial and antioxidant activities. The agrobiological characteristics of the two species growing in Kazanlak were analyzed; therefore, high variability in the population of N. transcaucasica and comparative homogeneity in N. cataria was shown. The species N. transcaucasica contained 0.28% essential oil with main components ß-citronellol (52.05%), eucalyptol (7.34%), ß-citronellal (6.06%), germacrene D (5.45%), (Z)-ß-ocimene (5.14%), and ß-caryophyllene (3.06%). The species N. cataria consisted of 0.19% essential oil with main components ß-citronellol (26.31%), geraniol (15.92%), neral (11.45%), nerol (9.56%), carvacrol (6.04%), and ß-citronellal (5.35%). The antibacterial activity against Gram-positive bacteria Listeria monocytogenes and Staphylococcus aureus and Gram-negative bacteria Escherichia coli (E. coli) and Salmonella enterica subsp. enterica serovar Abony was determined. The essential oils showed antimicrobial activity only against E. coli. The diameters of the inhibition zones were found to be 26 mm for the species N. transcaucasica and 10 mm for the species N. cataria. The antioxidant activity of the two essential oils was also determined by four different methods, DPPH, ABTS, FRAP, and CUPRAC, with the highest values for the ABTS radical, for the species N. transcaucasica (48.72 µM TE/mL), and the species N. cataria (310 µM TE/mL).

Recent development in the preservation effect of lactic acid bacteria and essential oils on chicken and seafood products.

Chicken and seafood are highly perishable owing to the higher moisture and unsaturated fatty acids content which make them more prone to oxidation and microbial growth. In order to preserve the nutritional quality and extend the shelf-life of such products, consumers now prefer chemical-free alternatives, such as lactic acid bacteria (LAB) and essential oils (EOs), which exert a bio-preservative effect as antimicrobial and antioxidant compounds. This review will provide in-depth information about the properties and main mechanisms of oxidation and microbial spoilage in chicken and seafood. Furthermore, the basic chemistry and mode of action of LAB and EOs will be discussed to shed light on their successful application in chicken and seafood products. Metabolites of LAB and EOs, either alone or in combination, inhibit or retard lipid oxidation and microbial growth by virtue of their principal constituents and bioactive compounds including phenolic compounds and organic acids (lactic acid, propionic acid, and acetic acid) and others. Therefore, the application of LAB and EOs is widely recognized to extend the shelf-life of chicken and seafood products naturally without altering their functional and physicochemical properties. However, the incorporation of any of these agents requires the optimization steps necessary to avoid undesirable sensory changes. In addition, toxicity risks associated with EOs also demand the regularization of an optimum dose for their inclusion in the products.

Development and Application of Edible Coatings with Malva sylvestris L. Extract to Extend Shelf-Life of Small Loaf.

Edible coatings that have a recognized ecological effect are an alternative to retard the processes of moisture evaporation and mold growth in bakery products. The aim of the present research was to study the influence of Malva sylvestris L. (mallow) flowers' extract on the antimicrobial activity of edible coatings of three types of polysaccharides, pectin/P/, xanthan/X/ and carboxymethylcellulose/C/, as well as to analyze their effect on the freshness and microbiological status of coated small loaves during storage. It was found that the presence of a mallow extract had a positive effect on the fungicidal and yeasticidal activities of the X and C coatings. The loaves were evaluated for their physical (moisture, color), textural (firmness and crumb firming kinetics) and microbiological characteristics. The coatings (P, X and C) with mallow extract had the strongest moisture-retaining effect on the loaves' crumb. The coatings with X and with P (with/without mallow extract) significantly slowed down the crumb firming process, and the value of the rate constant for the crumb firming (k) is the lowest for the X coating-0.1815 day-1. The smallest changes in the crust color were reported when mallow-based coatings were used. They have also been proven to have the lowest microbial load when they are stored for up to three days. This study shows that polysaccharide edible coatings with an active mallow component have significant potential to extend the shelf life of bakery products.

Chemical Composition of Pinus nigra Arn. Unripe Seeds from Bulgaria.

The present paper aims to investigate the chemical composition of unripe black pine seeds obtained from Bulgaria. The lipid fraction was evaluated in unripe seeds, and the cellulose, total carbohydrates, glucose, fructose, and sucrose were evaluated in seedcakes. The major fatty acid identified in the Pinus nigra seed oil was unsaturated linoleic acid (44.2%), followed by the saturated palmitic acid (31.2%). The amount of unsaturated pinolenic (10.5%) and oleic acids (8.8%) was also rather high. The amino acid composition of the protein fraction of seedcakes was also determined. The amino acid composition was represented mainly by asparagine (3.92 mg/g), serine (3.79 mg/g), alanine (3.65 mg/g), arginine (3.32 mg/g), phenylalanine (2.98 mg/g), lysine (2.85 mg/g), proline (2.69 g/mg), tryptophan (2.44 mg/g), valine (2.33 mg/g), isoleucine (2.28 mg/g), and tyrosine (2.05 mg/g). The mineral content (N, P, K, Mg, Na, and Cu) of the seedcakes was evaluated, as the amount of K (8048.00 mg/kg) and Mg (172.99 mg/kg) were the highest in the samples. These findings emphasized the potential use of the unripe black pine seeds in different areas due to their chemical importance and values.

In Vitro Studies on the Antimicrobial and Antioxidant Activities of Total Polyphenol Content of Cynara humilis from Moulay Yacoub Area (Morocco).

In Morocco, Cynara humilis L. is used in traditional medicine. The objective of this research was to research the antioxidant and antimicrobial properties of hydroethanolic extracts from the C. humilis plant's leaves and roots. The content of polyphenols and flavonoids was evaluated using Folin-Ciocalteu's and aluminum chloride assays. Two techniques were used to evaluate antioxidant properties: antioxidant capacity in total (TAC) and 2,2-diphenyl-1-picrylhdrazyl (DPPH). In antimicrobial assays, five pathogenic microbial strains were studied including two Escherichia coli, one coagulase-negative Staphylococcus and Klebsiella pneumoniae, and one Candida albicans, by two techniques: agar disk diffusion and microdilution. Leaves had a greater content of flavonoids 27.07 mg QE/g of extract and the polyphenols 38.84 mg GAE/g of extract than root 24.39 mg QE/g of extract and 29.39 mg GAE/g of extract, respectively. The TAC test value of the 0.77 mg AAE/g extract in the leaf extract was found to be significantly greater than that of the 0.60 mg EAA/g extract in the root extract. The DPPH antioxidant assay IC50 values of the root and leaf extract were 0.23 and 0.93 µg/mL, respectively. C. humilis extracts showed an antimicrobial effect against all tested strains, the inhibitory zone (DIZ) have values in the range between 12 and 15 mm. Moreover, the root extract showed the lowest minimum inhibitory concentration (MIC) against coagulase-negative Staphylococcus with an IC50 value of 6.25 mg/mL. The higher content of flavonoids and polyphenols in the hydroethanolic extracts of C. humilis leaves and roots demonstrates that they have a significant antimicrobial and antioxidant effect, as found in this study.

QSAR, ADMET In Silico Pharmacokinetics, Molecular Docking and Molecular Dynamics Studies of Novel Bicyclo (Aryl Methyl) Benzamides as Potent GlyT1 Inhibitors for the Treatment of Schizophrenia.

Forty-four bicyclo ((aryl) methyl) benzamides, acting as glycine transporter type 1 (GlyT1) inhibitors, are developed using molecular modeling techniques. QSAR models generated by multiple linear and non-linear regressions affirm that the biological inhibitory activity against the schizophrenia disease is strongly and significantly correlated with physicochemical, geometrical and topological descriptors, in particular: Hydrogen bond donor, polarizability, surface tension, stretch and torsion energies and topological diameter. According to in silico ADMET properties, the most active ligands (L6, L9, L30, L31 and L37) are the molecules having the highest probability of penetrating the central nervous system (CNS), but the molecule 32 has the highest probability of being absorbed by the gastrointestinal tract. Molecular docking results indicate that Tyr124, Phe43, Phe325, Asp46, Phe319 and Val120 amino acids are the active sites of the dopamine transporter (DAT) membrane protein, in which the most active ligands can inhibit the glycine transporter type 1 (GlyT1). The results of molecular dynamics (MD) simulation revealed that all five inhibitors remained stable in the active sites of the DAT protein during 100 ns, demonstrating their promising role as candidate drugs for the treatment of schizophrenia.

Application of Date (Phoenix dactylifera L.) Fruit in the Composition of a Novel Snack Bar.

The aim of the present study was to evaluate the possibilities for using date fruit from the Kingdom of Saudi Arabia in the formulation of a novel snack bar while replacing the used honey with date paste. The technological, textural, microbiological and sensory qualities of the obtained food products were evaluated during storage for 12 days after their production. Date palm fruit in the form of date paste was used as an ingredient in the composition of the new snack bars that also included nuts and dried fruits. Five formulations were prepared: a control bar, snack bar with 40% date paste, snack bar with 50% date paste, snack bar with 60% date paste, and snack bar with 70% dates paste. The resulting date paste's textural characteristics supported the bonding potential of the food system and gave a sweet taste to the final product. The formulations containing 50% date paste presented the highest overall acceptability and were the formulation with the best sensory characteristics. Thus, the addition of date paste in snack bars would be a good option to develop a functional product that contributes to rational nutrition principles. The obtained values in the current study confirmed the technological and functional potential of date fruit as a product that can find adequate application in the composition of foods with functional properties.

Chemical Compounds, Antitumor and Antimicrobial Activities of Dry Ethanol Extracts from Koelreuteria paniculata Laxm.

Koelreuteria paniculata Laxm. is used in traditional medicine and has various established biological activities, however, the species is considered to be a potentially invasive alien tree species for Bulgarian flora. However, there is still much to be studied about the phytochemical and biological characteristics of the species. The present study aimed to determine the chemical composition of the ethanol extracts of aerial plant parts, by GC-MS analysis, and to thereby evaluate their in vitro antitumor and antibacterial properties. All three extracts were tested against the HT-29 and PC3 tumor cell lines using the MTT assay. Fifty-six components were identified from leaf, flower, and stem bark extracts, and over 10% were the following constituents: pyrogallol, α-terpinyl acetate, neryl acetate, and α-terpinyl isobutanoate. The oxygenated monoterpenes predominated in the extracts, followed by the oxygenated aliphatics and phenylpropanoids. Significant antiproliferative activity on the HT-29 cell line (IC50-21.44 µg/mL and 23.63 µg/mL, respectively) was found for the flower and leaf extracts. Antibacterial activity was established for the following bacteria strains: Bacillus subtilis ATCC 6633, Bacillus cereus NCTC 10320, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 6027, and Proteus vulgaris ATCC 6380. The stem bark and flower extracts showed better antimicrobial potential. K. paniculata could be considered as a potential source of biologically active substances with antitumor and antibacterial properties.

Lactic Acid Bacteria as Antimicrobial Agents: Food Safety and Microbial Food Spoilage Prevention.

In the wake of continual foodborne disease outbreaks in recent years, it is critical to focus on strategies that protect public health and reduce the incidence of foodborne pathogens and spoilage microorganisms. Currently, there are limitations associated with conventional microbial control methods, such as the use of chemical preservatives and heat treatments. For example, such conventional treatments adversely impact the sensorial properties of food, resulting in undesirable organoleptic characteristics. Moreover, the growing consumer advocacy for safe and healthy food products, and the resultant paradigm shift toward clean labels, have caused an increased interest in natural and effective antimicrobial alternatives. For instance, natural antimicrobial elements synthesized by lactic acid bacteria (LAB) are generally inhibitory to pathogens and significantly impede the action of food spoilage organisms. Bacteriocins and other LAB metabolites have been commercially exploited for their antimicrobial properties and used in many applications in the dairy industry to prevent the growth of undesirable microorganisms. In this review, we summarized the natural antimicrobial compounds produced by LAB, with a specific focus on the mechanisms of action and applications for microbial food spoilage prevention and disease control. In addition, we provide support in the review for our recommendation for the application of LAB as a potential alternative antimicrobial strategy for addressing the challenges posed by antibiotic resistance among pathogens.

Comparative Study on the Phytochemical Composition and Antioxidant Activity of Grecian Juniper (Juniperus excelsa M. Bieb) Unripe and Ripe Galbuli.

Grecian juniper (Juniperus excelsa M. Bieb.) is an evergreen tree and a rare plant found in very few locations in southern Bulgaria. The aim of this study was to evaluate the phytochemical content and antioxidant potential of J. excelsa unripe and ripe galbuli from three different locations in Bulgaria. The essential oil content ranged between 1.9% and 5.1%, while the lipid fraction yield was between 4.5% and 9.1%. The content of total chlorophyll was 185.4-273.4 µg/g dw. The total carotenoid content ranged between 41.7 and 50.4 µg/g dw of ripe galbuli, and protein content was between 13.6% and 16.4%. Histidine (5.5 and 8.0 mg/g content range) and lysine (4.0 and 6.1 mg/g) were the major essential amino acids. The antioxidant potential of the 95% and 70% ethanol extracts was analyzed using four different methods. A positive correlation between the antioxidant potential and phenolic content of the galbuli was found. The results obtained in this study demonstrated the differences in phytochemical composition and antioxidant capacity of J. excelsa galbuli as a function of maturity stage and collection locality.