Characterization of Silybum marianum and Silybum eburneum seed oils: Phytochemical profiles and antioxidant properties supporting important nutritional interests.

Milk thistle seed oil is still not a well-known edible oil. Silybum marianum (milk thistle), is present in several countries and is the only known representative of the genus Silybum. However, Silybum eburneum, which is an endemic plant in Spain, Kenya, Morocco, Algeria, and Tunisia, is considered a marginalized species. The present work is the first report that gives information on the lipid and phenolic profiles of Tunisian S. eburneum seed oil compared to those of Tunisian S. marianum seed oil. In addition, the antioxidant properties of these oils were determined with DPPH, FRAP, and KRL assays, and their ability to prevent oxidative stress was determined on human monocytic THP-1 cells. These oils are characterized by high amounts of unsaturated fatty acids; linoleic acid and oleic acid are the most abundant. Campesterol, sitosterol, stigmasterol, and ß-amyrin were the major phytosterols identified. α-tocopherol was the predominant tocopherol found. These oils also contain significant amounts of phenolic compounds. The diversity and richness of Silybum marianum and Silybum eburneum seed oils in unsaturated fatty acids, phenolic compounds, and tocopherols are associated with high antioxidant activities revealed by the DPPH, FRAP, and KRL assays. In addition, on THP-1 cells, these oils powerfully reduced the oxidative stress induced by 7-ketocholesterol and 7ß-hydroxycholesterol, two strongly pro-oxidant oxysterols often present at increased levels in patients with age-related diseases. Silybum marianum and Silybum eburneum seed oils are therefore important sources of bioactive molecules with nutritional interest that prevent age-related diseases, the frequency of which is increasing in all countries due to the length of life expectancy.

Tunisian Silybum Species: Important Sources of Polyphenols, Organic Acids, Minerals, and Proteins across Various Plant Organs.

Silybum marianum and Silybum eburneum are wild edible Mediterranean plants used in the human diet. This study presents the initial findings on the phytochemical characterization of Tunisian S. marianum and S. eburneum organs. It examined their mineral, sugar, organic acid, polyphenolic, and seed storage protein contents, as well as their antioxidant potential. In S. marianum, stems had high sodium and potassium contents, while the immature and mature seeds were rich in calcium and magnesium. However, S. eburneum had high potassium levels in stems and high sodium and calcium levels in the flowers. S. marianum showed substantial fructose variation among its organs. Conversely, S. eburneum exhibited significant heterogeneity in glucose, sucrose, and maltose levels across its organs, with maltose exclusively detected in the immature seeds. A notable organ-dependent distribution of organic acids was observed among the two species. Higher levels of phenolic contents were detected in both mature and immature seeds in both species compared to the other plant parts. The seeds possessed higher antioxidant activities than other plant organs. In both S. marianum and S. eburneum seeds, albumins and globulins were the predominant protein fractions. This study brings evidence supporting the important potential of Silybum organs as sources of nutrients with antioxidant properties for producing functional food.

Chemical Composition of Essential Oils from Eight Tunisian Eucalyptus Species and Their Antifungal and Herbicidal Activities.

Eucalyptus species are known to produce metabolites such as essential oils (EOs) that play an important role in the control of weeds, pests and phytopathogenic fungi. The aims of this study were as follows: (i) to determine the chemical composition of the EOs derived from eight Eucalyptus species growing in Tunisia, and (ii) to study their possible antifungal and herbicidal activities. EOs were obtained by hydrodistillation from the dried leaves of eight Eucalyptus species, namely, E. angulosa, E. cladocalyx, E. diversicolor, E. microcoryx, E. ovata, E. resinifera, E. saligna and E. sargentii, and the determination of their composition was achieved by GC and GC-MS. The EOs' antifungal activities were tested against four Fusarium strains, and the EOs' herbicidal properties were evaluated on the germination and seedling growth of three annual weeds (Trifolium campestre, Lolium rigidum and Sinapis arvensis) and three cultivated crop species (Lepidium sativum, Raphanus sativus and Triticum durum). The EO yields ranged between 0.12 and 1.32%. The most abundant components found were eucalyptol, α-pinene, p-cymene, trans-pinocarveol, α-terpineol and globulol. All EOs showed significant antifungal activity against the four phytopathogenic Fusarium strains. E. cladocalyx EO exhibited the highest level of antifungal activity, and the greatest inhibition of seed germination was obtained even at lowest concentrations used. These findings suggested that E. resinifera, E. ovata and E. cladocalyx EOs could have applications in agriculture as possible biopesticides, as Fusarium antagonists and as bioherbicides.

HPLC-MS Profiling, Antioxidant, Antimicrobial, Antidiabetic, and Cytotoxicity Activities of Arthrocnemum indicum (Willd.) Moq. Extracts.

The purpose of this study was to evaluate for the first time the phytochemical constituents and biological properties of three (ethanol, acetone, and hexane) Arthrocnemum indicum (Willd.) Moq. (A. indicum) extracts. Quantitative analysis revealed the significantly (p < 0.05) dominance of ethanolic extract on total polyphenol (TPC; 303.67 ± 4.16 mg GAE/g DR) and flavonoid (TFC; 55.33 ± 2.52 mg CE/g DR) contents than the other extracts, also displaying high and equipotent condensed tannin (TCTC) contents as the acetone extract. The qualitative HPLC-MS analysis elucidates 19 and 18 compounds in ethanolic and acetonic extracts, respectively, belonging to the phenolics and flavonoids chemical classes. The extracts were also screened for their in vitro antioxidant activities using 1,1-diphenyl-2-picrylhydrazyl, superoxide anion, and ferric ion (Fe3+) reducing antioxidant power (FRAP), demonstrating the potent antioxidant activity of ethanolic extract, due to its stronger scavenging DPPH• (IC50 = 7.17 ± 1.26 µg/mL) which is not significantly (p > 0.05) different from the positive control, BHT (IC50 = 10.70 ± 0.61 µg/mL), however moderate activity through FRAP and superoxide anion radicals have been observed. Four Gram-positive, four Gram-negative bacteria, and four pathogenic fungi were used for the antimicrobial activity. In addition, S. epidermidis, M. luteus, E. faecalis, C. glabrata, C. parapsilosis, C. krusei were found to be the most susceptible strains towards ethanolic extract. Cytotoxicity values against human colon adenocarcinoma cells (HT29) and human epidermoid cancer cells (Hep2), and one continuous cell lineage control (Vero) revealed that the HT29 cancer cell line was the most responsive to A. indicum shoot extract treatment and significantly (p < 0.05) different from the other cancer cells. Moreover, when tested for their antidiabetic inhibitory effect, ethanol extract recorded the highest antidiabetic effect with IC50 = 13.17 ± 1.04 mg/mL, which is 8.4-fold higher than acetone extract. Therefore, the present study provides new findings on the use of A. indicum shoot ethanolic extract to cure many incurable diseases.

Moringa oleifera leaves: could solvent and extraction method affect phenolic composition and bioactivities?

This study was carried out to evaluate the effect of extraction methods (direct maceration (DM) and successive maceration (SM)) and solvents (dichloromethane (DCM), ethyl acetate (EAc), butanol (But), and aqueous extraction (Aqu)) on the phenolic composition and biological activities of Moringa oleifera leaves cultivated for the first time in Tunisia. Total polyphenol content (TPC), total flavonoid content (TFC) and LC-MS analysis were performed for all extracts. Antioxidant potential by DPPH, metal chelating, and FRAP assays, antibacterial activity against Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922) by the minimum inhibitory concentration method (MIC) and cytotoxic properties against lung cancer cells (A549), were determined. Phenolic compounds and biological activities of M. oleifera leaves depend on the method and the solvent used for the extraction of these bioactive substances. The But extract prepared by SM method exhibited the highest amounts of TPC (103.06 ± 0.5 mg GAE/g DE) and showed the strongest potential antioxidant (CI50 = 0.26 mg/mL on DPPH test), antibacterial (MIC = 250 µg/mL) and cytotoxic activities (GI50 = 69.9 µg/mL). LC-MS analysis showed that 28 phenolic compounds of 33 tested standards were found in M. oleifera leaves. The But extract obtained by SM method exhibited the highest amounts of rutin, quercetin and syringic acid.

Phytochemical Constituents and Antioxidant Activity ofOudneya Africana L. Leaves Extracts: Evaluation Effects on Fatty Acids and Proteins Oxidation of Beef Burger during Refrigerated Storage.

Five Oudneya Africana (OA) leaves extracts were screened for their total phenolic (TPC), total flavonoid (TFC), condensed tannins (CTC) content, as well as their antioxidant capacity. The highest amount of TPC (661.66 ± 0.08 mg GAE/g), TFC (344.68 ± 0.44 mg QE/g) and TCT (90.18 ± 0.49 mg CE/g) was recorded to ethanol, acetone, and dichloromethane extracts, respectively. For 2,2-diphenyl-1-picrylhydrazyl (DPPH) (22.00 ± 0.03 µg/mL) and Reducing Power Assay (FRAP) (269.00 ± 0.01µg/mL) assays, ethanol extract showed the potent activity, while with ABTS test, acetone extract was the most active (761.15 ± 0.09 µg/mL). HPLC-MS analysis of acetonic and ethanolic extracts reveals the predominance of quinic acid, chlorogenic acid, 4-O-caffeoylquinic acid, and rutin compounds. The addition effect evaluation of OA extracts in beef burger preservation demonstrates the powerful effect (p < 0.05) of acetonic and ethanolic ones (0.03%) to inhibit lipids oxidation during storage for 10 days, given by the lowest increase in Thiobarbituric Acid-reactive Substances (TBARS) values as compared to the (-) control with a significant difference between free thiols values. In addition, these two extracts appear to be effective (p < 0.05) for pH stability, color, and sensory parameters as compared to (+) and (-) controls and aqueous extract. Hamburger odour was considered as a dependent variable in multiple linear regression analysis, where the models results showed that physicochemical parameters determine more burger odour than sensorial ones.

Chemical composition and in vitro evaluation of antioxidant, antimicrobial, cytotoxicity and anti-acetylcholinesterase properties of Tunisian Origanum majorana L. essential oil.

This study investigated the chemical composition and evaluated the antioxidant, antimicrobial, cytotoxic and anti-acetylcholinesterase properties of Tunisian Origanum majorana essential oil. The findings showed that the oil exhibited high activity, particularly in terms of reducing power and ß-Carotene bleaching, inducing higher IC50 values than BHT. The oil showed an important antimicrobial activity against 25 bacterial and fungal strains. In fact, the IZ, MIC and MBC values recorded for the bacterial strains were in the range of 8 ± 0-18.33 ± 0.57 mm, 0.097-3.125 and 0.39-6.25 mg/mL, respectively. The IZ, MIC and MFC values of the fungal strains varied between 11±0-28 ± 0 mm, 0.058-0.468 mg/mL and 0.234-1.875 mg/mL, respectively. A low cytotoxic effect was observed against cancer (Hep-2 and HT29) and continuous cell lineage (Vero), with CC50 values ranging from 13.73 to 85.63 mg/mL. The oil was also evaluated for anti-acetylcholinesterase effects, which showed that it exhibited significant activity with IC50 values reaching 150.33 ± 2.02 µg/mL.

Composition and intraspecific chemical variability of the essential oil from Artemisia herba-alba growing wild in a Tunisian arid zone.

The intraspecific chemical variability of essential oils (50 samples) isolated from the aerial parts of Artemisia herba-alba Asso growing wild in the arid zone of Southeastern Tunisia was investigated. Analysis by GC (RI) and GC/MS allowed the identification of 54 essential oil components. The main compounds were ß-thujone and α-thujone, followed by 1,8-cineole, camphor, chrysanthenone, trans-sabinyl acetate, trans-pinocarveol, and borneol. Chemometric analysis (k-means clustering and PCA) led to the partitioning into three groups. The composition of two thirds of the samples was dominated by α-thujone or ß-thujone. Therefore, it could be expected that wild plants of A. herba-alba randomly harvested in the area of Kirchaou and transplanted by local farmers for the cultivation in arid zones of Southern Tunisia produce an essential oil belonging to the α-thujone/ß-thujone chemotype and containing also 1,8-cineole, camphor, and trans-sabinyl acetate at appreciable amounts.

Chemical composition and biological activities of Tunisian Cuminum cyminum L. essential oil: a high effectiveness against Vibrio spp. strains.

Essential oil extracted by hydrodistillation from Tunisian variety of Cuminumcyminum was characterized by means of GC and GC-MS. Twenty-one components were identified and C. cyminum contained cuminlaldehyde (39.48%), gamma-terpinene (15.21%), O-cymene (11.82%), beta-pinene (11.13%), 2-caren-10-al (7.93%), trans-carveol (4.49%) and myrtenal (3.5%) as a major components. Moreover, C. cyminum oil exhibited higher antibacterial and antifungal activities with a high effectiveness against Vibrio spp. strains with a diameter of inhibition zones growth ranging from 11 to 23 mm and MIC and MBC values ranging from (0.078-0.31 mg/ml) to (0.31-1.25mg/ml), respectively. On the other hand, the cumin oil was investigated for its antioxidant activities using four different tests then compared with BHT. Results showed that cumin oil exhibit a higher activity in each antioxidant system with a special attention for beta-carotene bleaching test (IC(50): 20 microg/ml) and reducing power (EC(50): 11 microg/ml). In the light of these findings, we suggested that C. cyminum essential oil may be considered as an interesting source of antibacterial, antifungal and antioxidants components used as potent agents in food preservation and for therapeutic or nutraceutical industries.