Ocimum basilicum is a valuable source of bioactive metabolites with high preventive and therapeutic effectiveness. Here we aimed to investigate the effect of phenological stages (vegetative and flowering stages) on essential oil composition and biological activities of two varieties of O. basilicum (Fino Verde variety and Genovese varieties). To this end, the level of essential oils, flavonoids and phenols, as well as antioxidant and antifungal activities were measured. At the metabolic level, essential oil at vegetative stage of O. bailicum Fino Verde and Genovese variety was constituted by 22 and 26 compounds representing 71.68% and 82.54% of the total oil, respectively. Where germacrene D (10.07%), bicyclogermacrene (6.07%) and β-elemene (4.88%) were the most present components in Fino Verde variety. Moreover, 22.19% are oxygenated monoterpenes represented mainly by the linalool (15.18%) and 1.8 cineole (6.36%) in Genovese variety. The individuals of essential oils were significantly increased to 40 components in Fino Verde variety (98.01% of total essential oil) and decreased to 15 components (95.6% of total essential oil) in Genovese variety at flowering stage. At this stage, the oxygenated monoterpenes (78.4%) were the major fraction represented by linalool (40.1%) and 1.8 cineole (30.96%) in Fino Verde variety, however 64.69% were esters which mainly represented by the methyl cinnamate (64.69%), and 16.83% of oxygenated monoterpenes and Linalool (12.7%) were recorded for Genovese variety. Genovese variety showed the highest levels at both vegetative and flowering stage compared to Fino Verde variety. At flowering stage, the two varieties showed high antioxidant and antifungal activities. Overall, O. basilicum properties offer prospects for their use as a source, particularly at flowering stage to extend new medicines based on natural bioactive molecules.

Marrubium vulgare is a valuable source of natural bioactive molecules with high preventive and therapeutic effectiveness. Therefore, this study aimed to study the chemical polymorphism of natural populations of M. vulgare in Tunisia by quantitative chemical markers and the estimation of divergence between populations. Phytochemical analyses of the eight natural populations of Tunisian Marrubium vulgare prospected in different bioclimatic stages, revealed 42 compounds of essential oils representing 96.08% to 100% of the total oil. Hydrocarbon sesquiterpenes were the main fraction of all the populations studied and β-bisabolene was the major compound (from 30.11% to 71.35% of the total oil). The phytochemical investigation of the M. vulgare plant indicated the presence of essential oil with significant percentages of phenolic compounds. A significant quantitative and qualitative variation in the essential oils is detected for both major and minor compounds. The principal components analysis (PCA) performed in the single and combined traits provides a good distinction among populations, not according to their geographical and/or bioclimatic origins. Moreover, the phytochemical analysis of the leaves showed that the Tunisian populations, i.e., the populations of Kasserine, Kef, and Beja, were very rich in phenolic compounds (from 20.8 to 44.65 mg GAE/g DW). Flavonoids compounds were also the main class of total polyphenols present in all the tested populations (from 8.91 to 37.48 mg RE/g DW). The quantitative genetic diversity estimated by the population’s structure, based on PCA analysis, was an adaptation to the changes in the environmental conditions. Overall, our study indicated that natural populations of M. vulgare had different chemotypes of essential oils and they were rich in phenolic compounds, particularly flavonoids, which opens a new prospect for industrial use and differential exploitation of this species.

Edible sprouts are rich in flavonoids and other polyphenols, as well as proteins, minerals, and vitamins. Increasing sprout consumption necessitates improving their quality, palatability, and bioactivity. The purpose of this study was to test how KNO₃ priming affects the sprouting process species on three Medicago species (Medicago indicus, Medicago interexta, and Medicago polymorpha) and their nutritional values. Targeted species of Medicago were primed with KNO₃, and the levels of different primary and secondary metabolites were determined. KNO₃ induced biomass accumulation in the sprouts of the three species, accompanied by an increased content of total mineral nutrients, pigments, vitamins, and essential amino acids. Besides, our results showed that KNO₃ enhanced the activity of nitrate reductase (NR), glutamate dehydrogenase (GDH), and glutamine synthetase (GS) enzymes, which are involved in the nitrogen metabolism and GOGAT cycle, which, in turn, increase the nitrogen and protein production. KNO₃ treatment improved the bioactive compound activities of Medicago sprouts by increasing total phenolic and flavonoid contents and enhancing the antioxidant and antidiabetic activities. Furthermore, species-specific responses toward KNO₃ priming were noticeable, where Medicago interexta showed the highest antioxidant and antidiabetic activities, followed by Medicago polymorpha. Overall, this study sheds the light on the physiological and biochemical bases of growth, metabolism, and tissue quality improvement impact of KNO₃ on Medicago sprouts.

Pelargonium graveolens, rose-scented geranium, is commonly used in the perfume industry. P. graveolens is enriched with essential oils, phenolics, flavonoids, which account for its tremendous biological activities. Laser light treatment and arbuscular mycorrhizal fungi (AMF) inoculation can further enhance the phytochemical content in a significant manner. In this study, we aimed to explore the synergistic impact of these two factors on P. graveolens. For this, we used four groups of surface-sterilized seeds: (1) control group1 (non-irradiated; non-colonized group); (2) control group2 (mycorrhizal colonized group); (3) helium-neon (He-Ne) laser-irradiated group; (4) mycorrhizal colonization coupled with He-Ne laser-irradiation group. Treated seeds were growing in artificial soil inculcated with Rhizophagus irregularis MUCL 41833, in a climate-controlled chamber. After 6 weeks, P. graveolens plants were checked for their phytochemical content and antibacterial potential. Laser light application improved the mycorrhizal colonization in P. graveolens plants which subsequently increased biomass accumulation, minerals uptake, and biological value of P. graveolens. The increase in the biological value was evident by the increase in the essential oils production. The concomitant application of laser light and mycorrhizal colonization also boosted the antimicrobial activity of P. graveolens. These results suggest that AMF co-treatment with laser light could be used as a promising approach to enhance the metabolic content and yield of P. graveolens for industrial and pharmaceutical use.