Biological activities and chemical characterization of the Lebanese endemic plant Origanum ehrenbergii Boiss

Phytochemical Profile, GC-MS Profiling and In Vitro Evaluation of Some Biological Applications of the Extracts of Origanum syriacum L. and Cousinia libanotica D.C

Indigenous to Lebanon, Origanum syriacum L. and Cousinia libanotica D.C. are notable plants in the Middle East, with O. syriacum known for its aromatic qualities and C. libanotica being less explored. Both plants have a significant role in traditional medicine for treating various ailments. This study aimed to evaluate the phytochemical composition and biological properties of the extracts from these plants. The extracts were obtained through cold maceration with solvents of increasing polarity. The ethyl acetate extract of O. syriacum exhibited the highest total polyphenol content. High-performance liquid chromatography (HPLC) identified fifteen compounds in both C. libanotica and O. syriacum extracts, whereas gas chromatography-mass spectrometry (GC-MS) analysis unveiled 179 volatile compounds. Notably, the O. syriacum-MeOH extract showed moderate antioxidant activity. Both plants' methanolic extracts demonstrated significant anti-Alzheimer's potential. The O. syriacum-dichloromethane and C. libanotica-cyclohexane extracts displayed the highest cytotoxicities against the HCT-116 cell line. For anti-proliferative activity against the Caco-2 cell line, the O. syriacum-methanol and C. libanotica-cyclohexane extracts were the most effective. This study provides valuable insights into the phytochemistry and potential therapeutic applications of extracts from these two oriental plant species.

Phenolic content, antioxidant and antimicrobial activities evaluation and relationship of commercial spices in the lebanese market

Lebanese cuisine is renowned for its distinctive flavours and vibrant aromas. In Lebanese cuisine, spices are not just used for their flavour; they are also valued for their medicinal properties. This study consists of evaluating and comparing the total phenolic content and the antioxidant capacity of 21 samples of spices used in the Lebanese daily diet, such as cinnamon, allspice, coriander, cloves, etc. and the mixtures prepared in well-defined proportions. Several solvents were tested for the extraction of the phenolic compounds from spices, and the water and ethanol (v/v) mixture were retained for this study. Results showed that clove presented the highest polyphenol content (173.7 ± 2.98 mg Gallic Acid Equivalent (GAE)/g Dry Matter (DM)) and the highest antioxidant capacity by ABTS test (4875.68 ± 480.40 µmol trolox / g DM). and DPPH test (85.84 ± 0.5%). The examination of the results showed a positive significant correlation between the polyphenol contents and the antioxidant activity of the spices. The antimicrobial activity tested by the broth microdilution method was determined against Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Salmonella Enteritidis. The results showed high antimicrobial activity manifested by low value of minimum inhibitory concentration (MIC) (MIC < 2.4 µg/mL) for cinnamon, turmeric, white pepper, red pepper, allspice, clove and nutmeg. In conclusion, spices used in Lebanese cuisine, such as clove, cinnamon, allspice and spices, were rich in phenolic compounds and presented important potential health benefits.

Natural Antimicrobials: A Reservoir to Contrast Listeria monocytogenes

Natural environments possess a reservoir of compounds exerting antimicrobial activity that are forms of defence for some organisms against others. Recently, they have become more and more attractive in the food sector due to the increasing demand for natural compounds that have the capacity to protect food from pathogenic microorganisms. Among foodborne pathogens, Listeria monocytogenes can contaminate food during production, distribution, or storage, and its presence is especially detected in fresh, raw food and ready-to-eat products. The interest in this microorganism is related to listeriosis, a severe disease with a high mortality rate that can occur after its ingestion. Starting from this premise, the present review aims to investigate plant extract and fermented plant matrices, as well as the compounds or mixtures of compounds produced during microbial fermentation processes that have anti-listeria activity.

Comparative Study of Phytochemistry, Antioxidant and Biological Activities of Berberis libanotica Fruit and Leaf Extracts

Berberis libanotica Ehrenb. ex C.K. Schneider of the Berberidaceae family is an endemic Lebanese plant and is widely used in folk medicine. This study highlights the phytochemical composition and biological activities (in vitro) of fruit and leaf extracts. The two organs were extracted by cold maceration with four solvents of increasing polarity: cyclohexane, dichloromethane, ethyl acetate and methanol. The extracts were screened for their chemical composition by HPLC-DAD to identify and quantify the phenolic compounds. Volatile compounds were detected by GC-MS. The antioxidant capacity through DPPH inhibition was tested. The anti-acetylcholinesterase, antibacterial and anti-proliferative activities were evaluated. Thirteen compounds, including 12 phenolics, were detected in the fruits, whereas 8 phenolic compounds were identified in the leaves. A total of 137 volatile compounds were identified in both organs. At 50 μg/mL, the methanolic leaf extract presented the highest antioxidant capacity, with an inhibition percentage of 54.9%. The dichloromethane fruit extract reduced the acetylcholinesterase activity by 65.3%. The cyclohexane leaf extract reduced the proliferation of the HCT-116 cells by 54.8%, while the dichloromethane fruit extract exhibited the best inhibition against the Caco-2 cells (54%). Interestingly, the minimum inhibitory concentration (MIC) value of the cyclohexane fruit extract against Salmonella enterica serovar Kentucky was 2.4 μg/mL, and the MIC value of the cyclohexane leaf extract against E. coli was 9.7 μg/mL.

Influence of Extraction Techniques and Solvents on the Antioxidant and Biological Potential of Different Parts of Scorzonera undulata

The genus Scorzonera has various medicinal values. Species belonging to this genus were traditionally used as drugs or in food. The current study aimed to determine the phytochemical composition, antioxidant activity, and biological properties of the tuber, leaf, and flower of Scorzonera undulata extracts, collected from the southwest of Tunisia. Phenolic compounds from the three parts were extracted using two solvents (water and ethanol) and two extraction techniques (maceration and ultrasound). The total phenolic content was measured by the Folin-Ciocalteu assay. Furthermore, the chemical composition of Scorzonera undulata extract was also investigated by the LC-ESI-MS method using phenolic acid and flavonoid standards. The variation of the extraction methods induced a variation in the real potentialities of the three parts in terms of bioactive molecules. However, the aerial part of S. undulata (leaves and flowers) showed, in general, the highest phenolic contents. Twenty-five volatile compounds have been detected by GC-MS in S. undulata extracts; among them, fourteen were identified before derivatization. The DPPH test showed that the aerial part of the plant has a higher antioxidant activity compared to the tuber (25.06% at 50 µg/mL for the leaf ethanolic extract obtained by ultrasound extraction). For most biological activities (anti-Xanthine, anti-inflammatory, and antidiabetic (alpha-amylase and alpha-glucosidase)), the aerial parts (flowers and leaves) of the plant showed the highest inhibition than tubers.

Chemical Characterization and Antioxidant, Antibacterial, Antiacetylcholinesterase and Antiproliferation Properties of Salvia fruticosa Miller Extracts

The Salvia fruticosa (Mill.) is the most medicinal plant used in Lebanon. The aim of this study is to investigate the phytochemical composition and the biological activities (in vitro) of its extracts. The plant was extracted by cold maceration with four solvents presenting an increasing polarity: cyclohexane (CHX), dichloromethane (DCM), ethyl acetate (EtOAc) and methanol (MeOH). The extracts were screened for their chemical composition by a HPLC-DAD detector for phenolic compounds identification and quantification and by GC-MS for volatile compounds detection. The antioxidant capacity (DPPH inhibition) was tested. Biological activities, mainly anti-Alzheimer activity (acetylcholinesterase inhibition), the antiproliferation of two human colon cancer cell lines (HCT-116 and Caco-2 cells) and antibacterial activity, were evaluated. Ten aromatic compounds were quantified by HPLC-DAD analysis. A total of 123 compounds were detected by GC-MS analysis. The MeOH extract showed a very interesting antioxidant activity with an inhibition percentage (IP) of 76.1% and an IC₅₀ of 19.4 μg/mL. The EtOAc extract exhibited the strongest inhibition against the acetylcholinesterase activity (IP = 60.6%) at 50 μg/mL. It also strongly inhibited the proliferation of the HCT-116 cells (IP = 87.5%), whereas the DCM extract gave the best result with the Caco-2 cells (IP = 72.3%). The best antibacterial activity was obtained with the MeOH extract against Staphylococcus aureus (MIC = 1.2 μg/mL) and with the EtOAc extract against Escherichia coli (MIC = 2.4 μg/mL). This study highlights the chemical composition and therapeutic potential of S. fruticosa. It is important to mention that the following chemical compounds were identified for the first time in plant extracts: 2,6,11,15-tetramethyl-hexadeca-2,6,8,10,14-pentaene; 4,5,6,7-tetrahydroxy-1,8,8,9-tetramethyl-8,9-dihydrophenaleno [1,2-b]furan-3-one; podocarpa-1,8,11,13-tetraen-3-one,14-isopropyl-1,13-dimethoxy; podocarpa-8,11,13-trien-3-one,12-hydroxy-13-isopropyl-,acetate; 3',8,8'-trimethoxy-3-piperidin-1-yl-2,2'-binaphthyl-1,1',4,4'-tetrone; and 2,3-dehydroferruginol, thus underlining the originality of this study.

Study on the Chemical Composition and the Biological Activities of Vitis vinifera Stem Extracts

Vitis vinifera (V. vinifera) is a herbaceous plant, cultivated worldwide and known for its biological benefits. The aim of this study is the investigation of the chemical composition as well as the determination of the biological potential of different grape stem extracts obtained by maceration and accelerated solvent extraction (ASE). The HPLC analysis of the tested extracts led to the identification of 28 compounds of which 17 were identified for the first time in grape plants, in addition to seven revealed in the stem part for the first time. Twenty-nine volatile molecules have been detected by GC-MS in the grape stem part; among them seven were identified for the first time in the grape plant. For the biological analysis, the ethyl acetate extract (EtOAc) obtained by maceration showed a significant potential regarding antioxidant activity (IC₅₀ = 42.5 µg/mL), anti-Alzheimer (IC₅₀ = 14.1 µg/mL), antidiabetic (IC₅₀ = 13.4 µg/mL), cytotoxic with HCT-116 (IC₅₀ = 12.5 µg/mL), and anti-inflammatory (IC₅₀ = 26.6 µg/mL) activities, as well as showing the highest polyphenol content (207.9 mg GAE/g DW).