Comparative study of the phenolic profile, antioxidant and antimicrobial activities of leaf extracts of five Juniperus L. (Cupressaceae) taxa growing in Turkey

Exploring chitosan-plant extract bilayer coatings: Advancements in active food packaging via polypropylene modification

UV-ozone activated polypropylene (PP) food films were subjected to a novel bilayer coating process involving primary or quaternary chitosan (CH/QCH) as the first layer and natural extracts from juniper needles (Juniperus oxycedrus; JUN) or blackberry leaves (Rubus fruticosus; BBL) as the second layer. This innovative approach aims to redefine active packaging (AP) development. Through a detailed analysis by surface characterization and bioactivity assessments (i.e., antioxidant and antimicrobial functionalities), we evaluated different coating combinations. Furthermore, we investigated the stability and barrier characteristics inherent in these coatings. The confirmed deposition, coupled with a comprehensive characterization of their composition and morphology, underscored the efficacy of the coatings. Our investigation included wettability assessment via contact angle (CA) measurements, X-ray photoelectron spectroscopy (XPS), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), which revealed substantial enhancements in surface concentrations of elements and functional groups of CH, QCH, JUN, and BBL. Scanning electron microscopy (SEM) unveiled the coatings' heterogeneity, while time-of-flight secondary ion mass spectrometry (ToF-SIMS) and CA profiling showed moderately compact bilayers on PP, providing active species on the hydrophilic surface, respectively. The coatings significantly reduced the oxygen permeability. Additionally, single-layer depositions of CH and QCH remained below the overall migration limit (OML). Remarkably, the coatings exhibited robust antioxidative properties due to plant extracts and exceptional antimicrobial activity against S. aureus, attributed to QCH. These findings underscore the pivotal role of film surface properties in governing bioactive characteristics and offer a promising pathway for enhancing food packaging functionality.

Mineral composition, the profile of phenolic compounds, organic acids, sugar and in vitro antioxidant capacity, and antimicrobial activity of organic extracts of Juniperus drupacea fruits

Juniperus drupacea fruit is widely used in traditional and complementary medicine in Turkey for the treatment of different diseases in various forms such as molasses and tar. This study was carried out to evaluate the phenolic compounds, organic acid, sugar, and macro- and micromineral distributions of methanol and water extracts of J. drupace fruit, as well as their antioxidant and antimicrobial potential. For this purpose, total phenolic content by spectrophotometer, phenolics, organic acids, and sugars distributions by HPLC in extracts of J. drupacea fruits, and macro- and micromineral element content by ICP-AES in fruit were determined. 2,2-diphenyl-l-picrylhydrazyl assay (DPPH assay) was used to evaluate in vitro antioxidant activity in extracts. The antimicrobial potential of J. drupacea fruit methanol extract against some gram-positive and gram-negative pathogenic bacteria was evaluated using disk diffusion and minimum inhibitory concentration (MIC) methods. The potassium macroelement and the iron microelement were found at high content in J. drupacea fruit. The total phenolic content in the methanol extracts was higher than the water extracts. Among the individual phenolic compounds, catechin, a flavonoid that was the highest in both extractions, was determined as 300.49 μg/g in methanol extract and 314.88 μg/g in water extract. DPPH scavenging activity was higher in methanol extracts. While the methanol extract of J. drupacea had no-inhibitory effect on the gram-negative bacteria tested, it exhibited a strong inhibition on the gram-positive bacteria Listeria innocua, Listeria monocytogenes, Staphylococcus carnosus, and Enterococcus faecalis.

Qualitative and Quantitative Analysis of the Major Bioactive Components of Juniperus chinensis L. Using LC-QTOF-MS and LC-MSMS and Investigation of Antibacterial Activity against Pathogenic Bacteria

Plants in the genus Juniperus have been reported to produce a variety of chemical components, such as coumarins, flavonoids, lignans, sterols, and terpenoids. Here, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) were applied to qualitatively and quantitatively analyze the major bioactive components in an ethanolic crude extract from the leaves of Juniperus chinensis L., which grows naturally in Korea. In addition, the antibacterial activity of the crude extract against pathogenic bacteria was investigated. Using LC-QTOF-MS analysis, we identified ten compounds, of which six were confirmed to be flavonoid and lignan-based components as the major bioactive components, i.e., isoquercetin, quercetin-3-O-α-l-rhamnoside, hinokiflavone, amentoflavone, podocarpusflavone A, and matairesinoside. Among them, a quantitative analysis performed using LC-MS/MS revealed that the levels of quercetin-3-O-α-l-rhamnoside and amentoflavone in the crude extract were 203.78 and 69.84 mg/g, respectively. Furthermore, the crude extract exhibited potential antibacterial activity against 10 pathogenic bacteria, with the highest antibacterial activity detected against Bordetella pertussis. Thus, further studies of the leaf extract of J. chinensis L. must be carried out to correlate the compounds present in the extract with the antibacterial activity and elucidate the mechanisms of action of this extract against bacteria.

Effects of Rubus fruticosus and Juniperus oxycedrus derivatives on culturability and viability of Listeria monocytogenes

The consumers' demand for safe foods without chemical additives increased the research for green solutions, based on natural antimicrobials. Plants can be an important source of bioactive compounds able to prevent the development of foodborne pathogens and spoilage microflora. This paper aimed to characterize phenolic extracts (PEs) and essential oils (EOs) obtained from Mediterranean Rubus fruticosus leaves and Juniperus oxycedrus needles and to evaluate their antimicrobial effects against Listeria monocytogenes Scott A. The growth dynamics with sub-lethal concentrations of plant derivatives were modeled and flow cytometry was used to better evidence the effect on cell viability and culturability. The results showed that these plant derivatives affected the growth of L. monocytogenes, increasing lag phase (about 40 h in the presence of PEs vs. 8 h in the control) and decreasing the final cell load of at least 1 log cycle with respect to the control. R. fruticosus EO was the most effective, determining an initial decrease of cell counts of about 6 log cycles, followed by a restart of growth after 10 h, with rate similar to the control (0.08 with R. fruticosus EO vs. 0.09 ((log CFU/ml)/h in the control) but significantly lower final cell load (7.33 vs. 8.92 log CFU/ml). According to flow cytometry, only R. fruticosus EO induced a relevant increase of dead cells, while the other plant derivatives determined different extent of sub-lethal cell injury. The discrepancy observed in some cases between viability and culturability could indicate the presence of cells not able to grow in culture media, whose fate needs to be further investigated to assess their potential recovery, thus bringing to an overestimation of the antimicrobial effect of these substances. This research contributed to increase the knowledge of these underused raw materials such as blackberry leaves and juniper needles that can be exploited in food and other industries.

Comparison of three antioxidants in chemical and biological assays on porcine oocytes during ageing in vitro

Our previous studies have already revealed that β-cryptoxanthin (BCX), hesperetin (HES), and icariin (ICA) antioxidants are effective for in vitro maturation (IVM) of porcine oocytes. In this study, we investigated which of BCX, HES, or ICA was more effective for IVM of porcine oocytes. The antioxidant properties were assessed with aged porcine oocytes and embryos by comparing 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl (DPPH), reducing power, and H2O2 scavenging activity assays. The chemical assay results demonstrated that BCX had a greater DPPH scavenging activity and reducing power than HES and ICA, compared with controls. However, the H2O2 scavenging activity of the antioxidants was similar when tested at the optimal concentrations of 1 μM BCX (BCX-1), 100 μM HES (HES-100), and 5 μM ICA (ICA-5). The biological assay results showed that BCX-1 treatment was more effective in inducing a significant reduction in reactive oxygen species (ROS), improving glutathione levels, and increasing the expression of antioxidant genes. In addition, BCX-1 inhibited apoptosis by increasing the expression of anti-apoptotic genes and decreasing pro-apoptotic genes in porcine parthenogenetic blastocysts. BCX-1 also significantly increased the blastocyst formation rate compared with the ageing control group, HES-100 and ICA-5. This study demonstrates that damage from ROS produced during oocyte ageing can be prevented by supplementing antioxidants into the IVM medium, and BCX may be a potential candidate to improve assisted reproductive technologies.

Zimbro (Juniperus communis L.) as a Promising Source of Bioactive Compounds and Biomedical Activities: A Review on Recent Trends

Plant-derived products and their extracted compounds have been used in folk medicine since early times. Zimbro or common juniper (Juniperus communis) is traditionally used to treat renal suppression, acute and chronic cystitis, bladder catarrh, albuminuria, leucorrhea, and amenorrhea. These uses are mainly attributed to its bioactive composition, which is very rich in phenolics, terpenoids, organic acids, alkaloids, and volatile compounds. In the last few years, several studies have analyzed the huge potential of this evergreen shrub, describing a wide range of activities with relevance in different biomedical discipline areas, namely antimicrobial potential against human pathogens and foodborne microorganisms, notorious antioxidant and anti-inflammatory activities, antidiabetic, antihypercholesterolemic and antihyperlipidemic effects, and neuroprotective action, as well as antiproliferative ability against cancer cells and the ability to activate inductive hepato-, renal- and gastroprotective mechanisms. Owing to these promising activities, extracts and bioactive compounds of juniper could be useful for the development of new pharmacological applications in the treatment of several acute and chronic human diseases.

Chemical and Antimicrobial Analyses of Juniperus chinensis and Juniperus seravschanica Essential Oils and Comparison with Their Methanolic Crude Extracts

Juniperus chinensis and Juniperus seravschanica are commonly used in the traditional folk medicine to treat microbial infection. In this study, the essential oils obtained from the leaves of J. chinensis growing in Malaysia and J. seravschanica growing in Oman were analysed by head space-solid phase microextraction-gas chromatography mass spectrometry (HS-SPME-GC-MS) and screened for antimicrobial activities against Escherichia coli (NCTC 10418), Pseudomonas aeruginosa (NCTC 10662), Bacillus subtilis ATCC6059, Micrococcus luteus (ATCC 9341), Staphylococcus aureus (NCTC 6571), and methicillin-resistant S. aureus (MRSA; ATCC 33591). To compare the antimicrobial activities of extracts using different extraction methods, methanol extraction was performed to obtain crude extracts from the leaves of J. chinensis and J. seravschanica for antimicrobial analysis. The HS-SPME-GS-MS analysis of the essential oils from the leaves of J. chinensis and J. seravschanica identified 37 and 36 components, respectively. Essential oils from these two species had distinctive chemical component profiles, with α-pinene (27.2%) as the major component of J. chinensis essential oil, while dl-limonene (45.2%) constitutes the major component of J. seravschanica essential oil. Essential oils of these two species shared only six similar terpenoids compounds: α-pinene, β-pinene, γ-elemene, sabinene, elemol, and 3-cyclohexen-1-ol. Overall, the essential oils showed antimicrobial activities against all the six bacterial strains tested, with the highest antagonistic activity against M. luteus and B. cereus; while, methanolic crude extracts showed the highest activities against S. aureus and MRSA strains. The methanolic crude extracts demonstrated significantly higher antibacterial activity against the Gram-positive bacteria (p < 0.005); while, the essential oils of Juniperus did not show significant differences between Gram-positive and Gram-negative bacteria. Future studies are needed to investigate the active compounds present in the essential oils and methanolic crude extracts that confer the selectivity in the antimicrobial activity.

Anti-Quorum Sensing and Antioxidant Activity of Essential Oils Extracted From Juniperus Species, Growing Spontaneously in Tebessa Region (East of Algeria)

The chemical composition of essential oils (EOs) extracted from the aerial parts of 2 species of Juniperus was determined by Gas Chromatography-Mass Spectrometry (GC-MS). In total, 65 and 58 compounds accounting for 90.3% and 89.8% of the whole chemical composition of Juniperus oxycedrus (JO) and Juniperus phoenicea (JP) were identified, respectively, with α-pinene, α-amorphene, terpinen-4-ol, α-terpinene, and β-elemene, as major components. For the first time, the capacity to inhibit quorum-sensing for Chromobacterium violaceum CV026 and CV12472 by the investigated EOs was evaluated. Both oils exhibited good violacein inhibition on CV12472 with 100.0 ± 0.0% inhibition at minimal inhibition concentration (MIC) values. Besides, the quorum-sensing inhibition of CV026 was high at MIC for JO essential oil from fruits (JOF, 16.3 ± 2.0 mm), JO leaves (JOL, 12.5 ± 3.5 mm), JP fruits (JPF, 19.7 ± 2.5 mm), and JP leaves (JPL, 21.1 ± 5.0 mm). On both CV12472 and CV026, essential oil from J. phoenicea leaves was the most active inhibitor. All investigated EOs inhibited swarming motilities in flagellated Pseudomonas aeruginosa (PA01) in a concentration-dependent manner, and those from JP were more active than EOs from JO. Moreover, these EOs showed good antioxidant potential according to DPPH● and FRAP methods, especially the EO from JO leaves with an IC50 DPPH● inhibition value of 20.2 ± 1.0 mg/mL. Based on the obtained results, the investigated EOs are good candidates to combat microbial resistance be used as alternatives to conventional antibiotics, and equally find applications in food biosafety as preservatives.

Chemical composition, antioxidant, antibacterial and cholinesterase inhibitory activities of three Juniperus species

The chemical composition, antioxidant, antibacterial and cholinesterase inhibitory activities of three Juniperus species were studied. The contents of total phenolic and 10 phenolic compounds were highest in Juniperus rigida Sieb.et Zucc., of which catechin and cumaric acid were the predominant phenolic compounds, but were lowest in Juniperus sibirica Burgsd. GC-MS analysis showed the highest contents of essential oils were in J. rigida (92.61%), followed by Juniperus formosana Hayata (87.30%) and J. sibirica (84.89%). The a-pinene was the most dominant compound in J. rigida (23.99%) and J. formosana (9.71%), however, it has not been detected in J. sibirica. Ethanol extracts showed the higher radical scavenging capacity in ABTS, FRAP and DPPH assays than essential oils. The essential oils and ethanol extracts of J.sibirica showed the strong antibacterial activity against Salmonella typhimurium and Escherichia coli. Three Juniperus species showed certain acetylcholinesterase and butyrylcholinesterase inhibitions and J. formosana showed better cholinesterase inhibitory.

The Contribution of Carotenoids, Phenolic Compounds, and Flavonoids to the Antioxidative Properties of Marine Microalgae Isolated from Mediterranean Morocco

This study aimed to investigate the potential of four sea water microalgae, isolated and cultivated at M′diq Bay in Morocco, as a new source of natural antioxidants. These microalgae belong to different classes, including Phaedactylium tricornitum (Bacillariophyceae), Nannochloropsis gaditana (Eustigmatophyceae), Nannochloris sp (Trebouxiophyceae), and Tetraselmis suecica (Chlorodendrophycea). The antioxidant properties were screened by the use of in vitro assays, namely 2,2-difenil-1-picrylhydrazyl, Ferric reducing antioxidant power, and Ferrous ions chelating activity, and compoundidentification was carried out in methanol and acetone extracts of both dried and fresh microalgae biomass by HPLC–PDA–MS analysis. Among the investigated microalgae, Phaedactylium tricornutum was the richest one regarding its carotenoid (especially all-E-fucoxanthin) and phenolic (especially protocatechuic acid) contents, as well as antioxidant activity (65.5%), followed by Nannochloris sp, Tetraselmis suicica, and Nannochloropsis gaditana, with antioxidant activity of 56.8%, 54.9%, and 51.1%, respectively.

Essential oil constituents of Juniperus oxycedrus L. and Cupressus sempervirens L. (Cupressaceae) growing in Aures region of Algeria

The purpose of this study was to determine the chemical composition of essential oils from the aerial parts of two species belonging to the Cupressaceae family growing in the Aures region of Algeria Juniperus oxycedrus and Cupressus Sempervirens. The analysis by GC-MS and GC-FID techniques showed the presence of 38 compounds in J. oxycedrus oil where the major constituents were manoyl oxide (23.5%), pentadecan-2-enone 6Z (12.6%), abietatriene (8.0%), abieta-8,11,13-triene-7-one (6.5%), cubebol (4.6%), epi-torilenol (3.8%) and α-cadinol (2.6%), while, a total of 65 compounds were showed in C. sempervirens oil where the major constituents were α-pinene (68.0%), epi-cedrol (6.1%), α-terpenyl acetate (3.5%) and germacrene D (2.5%). It is the first time that the compounds pentadecan-2-enone 6Z, abieta-8,11,13-trien-7-one, cubebol and epi-torilenol have been identified in our J. oxycedrus and epi-cedrol in C. sempervirens essential oils with high contents, as we noticed the absence of α-pinene in our J. oxycedrus essential oil.

Polyphenolic profile, antibacterial activity and brine shrimp toxicity of leaf extracts from six Tunisian spontaneous species

The aim of this study was to investigate the polyphenolic profile and biological properties of leaves acetonic extracts from six Tunisian spontaneous plants of Marrubium vulgare L., Rhus tripartita (Ucria) D.C., Hernaria fontanesii J. Gay subsp. fontanesii, Ziziphus lotus L., Plantago ovata Forsk., Thymelaea hirsuta (L.) Endl. Bioassay-guided and HPLC-PDA-ESI-MS procedures demonstrated that R. tripartita contained the highest amount of phenolic compounds (1475.1 µg/g), followed by Z. lotus (1087.8 µg/g) and P. ovata (1027.6 µg/g). Interestingly, in R. tripartita myricetin-3-O-galactoside turned out to be the most abundant one. The plant extracts showed antimicrobial efficacy against Listeria monocytogenes, Staphylococcus aureus and S. epidermidis including methicillin resistant strains; no activity was detected against Gram-negative bacteria. R. tripartita revealed the best MIC and MBC values and caused significant decrease of S. aureus biofilm. Both R. tripartita and Z. lotus did not display any toxicity against Artemia salina Leach (LC₅₀ > 1000 μg/mL).

Phytochemical Characterization and Biological Activities of a Hydroalcoholic Extract Obtained from the Aerial Parts of Matthiola incana (L.) R.Br. subsp. incana (Brassicaceae) Growing Wild in Sicily (Italy)

This study aimed to characterize the phenolic and the volatile constituents and to establish the antioxidant potential and the toxicity of a hydroalcoholic extract obtained from the leaves and flower buds of Matthiola incana (L.) R.Br. subsp. incana growing wild in Sicily (Italy). By HPLC-PDA/ESI-MS analysis, 12 phenolics (two phenolic acid derivatives and ten flavonoids) were identified, and eight of them were reported for the first time; luteolin-glucoside was the main component (57.07 mg/g±0.87 % RSD). By SPME-GC/MS, 47 volatile constituents were fully characterized, and dimethyl trisulfide turned out to be the most abundant one (33.24 %). The extract showed moderate activity both in the DPPH and in the reducing power assays (IC₅₀ =2.32±0.24 mg/mL; ASE/mL=12.29±0.42); it did not inhibit the lipid peroxidation, whereas it was found to possess good chelating properties reaching approximately 90 % activity at the highest tested dose. Moreover, the extract protected growth and survival from H₂ O₂ -induced oxidative stress in Escherichia coli. Finally, the extract was non-toxic against Artemia salina (LC₅₀ >1000 μg/mL). These findings increase the knowledge of M. incana subsp. incana and they could be helpful to a chemosystematic distinguishing of this subspecies also demonstrating that the aerial parts represent a safe source of antioxidants.