Twelve Tunisian Thymus algeriensis populations growing wild in different bioclimatic zones, extending from the subhumid to the upper-arid bioclimates, were compared regarding their phenolic composition and their ability to serve as antioxidant, anti-acetylcholinesterase, and antibacterial agents. A significant variation of phenol profile was observed between the analyzed populations, as assessed by ultra-high-performance liquid chromatography coupled with a diode array detector and an electrospray mass spectrometer (UHPLC-DAD-ESI/MSⁿ) technique. Rosmarinic acid was the main phenolic compound in most populations (383.8–1157.8 µg/mL extract), but still, those from the upper-arid bioclimatic zone were distinguished by the presence of carvacrol (1374.7 and 2221.6 µg/mL extract), which was absent in the remaining ones. T. algeriensis methanolic extracts were found to possess a substantial antioxidant and anti-acetylcholinesterase activities, with significant variation observed between populations, which were correlated to their phenolic contents. The antibacterial activity of the extracts tested against seven bacteria was revealed only by populations collected from upper-arid bioclimate and mainly associated with the presence of carvacrol. Extracts revealed a bacteriostatic effect against all bacteria (MIC = 1.4 mg/mL). Yet, the bactericidal activity (MBC = 1.4mg/mL) was restricted to the gram-negative bacteria Escherchia coli.

The main objective of this research was to study the biological characteristics in terms of antioxidant and antimicrobial activities of Ajuga iva and determine the best analytical and extraction methods applicable to this specie and studied compounds. A short screening of its nutritional value in terms of chemical composition is also included. A. iva leaves were analyzed for crude protein (CP), cell wall [neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL)], minerals, fatty acids, essential oils, and phenolic compounds. Mature aerial parts of A. iva were randomly collected during the Spring season from Mograne-Zaghouan, Tunisia. Leaves of A. iva contained 13.4 ± 0.4% CP, 26.3 ± 0.35% NDF, 20.2 ± 0.42% ADF, and 5.13 ± 0.21% ADL. Mineral content (13.0 ± 0.45%) was mainly composed of potassium (4.5% g DM) and magnesium (4.25% DM). Leaves of A. iva had linolenic (26.29 ± 0.760%) and linoleic (37.66 ± 2.35%) acids as the main components of the acid profile. Thymol was found to be the most dominant (23.43%) essential oil, followed by 4-vinylguaiacol (14.27%) and linalool (13.66%). HPLC-PDA-ESI-MS/MS analysis pointed out the presence of phytoecdysteroids. Phenolic acids and flavonoids, such as glycosylated derivatives of naringenin, eriodyctiol, and apigenin, were detected in the methanol extract of A. iva leaves. Our results underline the importance of choosing proper extraction methods and solvents to extract and characterize the described compounds profile of A. iva leaves. Results also show A. iva leaves as a potential source of functional ingredients with beneficial health-promoting properties. Overall, leaves of A. iva have low biological activities (antioxidant and antimicrobial activities) with a chemical composition suitable as a feed for ruminants in rangeland pasture. It also has low-grade antibacterial or medicinal characteristics when fed to ruminants.

This study investigates the chemical composition, nutritional profile, and biological activities of aqueous extracts from different organs (leaves, flowers, and stems) of Urtica urens collected in Tunisia. Significant organ-dependent variability was observed in both phytochemical composition and biological activities. Our results revealed that leaves extracts were characterized by the highest Calcium level (23354.44 ppm) and the lowest Na/k ratio. Flowers revealed high amounts of Potassium (16809.11ppm). Nevertheless, high amounts of Sodium (3.62 ppm) were detected in stems extracts. Leaves aqueous extracts showed the highest proportion of total phenols (47.83 mg GAE/g DW), flavonoids (10.30 mg RE/g DW) and flavanols (1.08 mg CE/g DW). However, the highest condensed tannins content was revealed for stems aqueous extracts (7.60 mg CE/g DW). Leaves extracts revealed the strongest biological activities, including higher antioxidant capacity (DPPH and ferric reducing power assays) and the most pronounced antibacterial effects against both Gram-positive and Gram-negative strains. In addition, insecticidal activity against Aphis gossypii varied depending on plant organ, concentration, and exposure time, with leaves generally showing the highest efficacy. UPLC-QTOF/MS analysis of leaf extracts revealed a diverse phenolic profile, including phenolic acids, flavonoids, flavonoid glycosides, and hydrolysable tannin derivatives compounds, which may contribute to the observed biological activities. Overall, these findings highlight the strong influence of plant organ on the chemical and biological properties of U. urens and suggest that leaves represent the most promising fraction for further investigation and potential applications in pharmaceutical, nutraceutical, and agroecological fields.