Exploring the synergistic potential of wild nettle and olive oil: bioactive compounds, antioxidant capacity, and antibacterial properties.

This study delved into the incorporation of wild nettle (Urtica dioica L.) leaves powder with virgin olive oil, exploring its potential to enhance nutritional value and health benefits. The antioxidant, antibacterial, and mineral-enrichment attributes of the resultant nettle-infused olive oil were investigated. Phenolic composition analysis revealed that an optimal maceration time of 30-40 minutes leads to maximal phenolic and flavonoid contents (57.66 mg GAE/100 g and 67.18 mg QE/100 g, respectively). The infused oil demonstrated superior radical scavenging activity (DPPH and ABTS assays) compared to virgin olive oil. Notably, nettle infusion significantly elevates zinc (10.12 mg/kg) and iron (13.85 mg/kg) contents. Antibacterial assays exhibited enhanced inhibition diameters and lower MIC and MBC values for nettle-infused oil against various bacterial strains. The study's findings underscore the potential of nettle infusion to enhance the nutritional and functional attributes of olive oil, holding promise for novel culinary and health applications.

Enhancing antioxidant and antibacterial properties of olive oil through garlic enrichment: a comprehensive study.

The amalgamation of garlic's antibacterial potency with olive oil's nutritional benefits provides a natural, effective way to boost health and counters microbial threats. This study explored the antioxidant and antibacterial traits of garlic-enriched virgin olive oil (VOO) samples, focusing on various garlic forms (fresh, oven-dried, freeze-dried). Comparative analysis revealed fresh garlic's highest total phenolic content, flavonoid content, and strongest DPPH scavenging activity. GC/MS analysis unveiled distinct volatile profiles. Fresh garlic oil contained elevated allyl-methy-sulfide, diallyl-trisulfide, methyl-propyl-disulfide levels. Antibacterial evaluation displayed substantial inhibition zones, especially fresh garlic oil against E. coli, and oven-dried/freeze-dried garlic oils against P. aeruginosa. Lower Minimal Inhibitory Concentration (MIC) values for fresh garlic oil and freeze-dried garlic oil against both Gram-negative and Gram-positive bacteria signify potent antibacterial activity of garlic-enriched VOO. These findings underscore garlic-enriched VOO's potential as natural antibacterial agents, fortified with antioxidant traits, while emphasizing drying methods' role in shaping volatile compounds.

Unraveling physiological, biochemical and molecular mechanisms involved in olive (Olea europaea L. cv. Chétoui) tolerance to drought and salt stresses.

Olive (Olea europaea L.) is an economically important crop for the Mediterranean basin, where prolonged drought and soil salinization may occur. This plant has developed a series of mechanisms to tolerate and grow under these adverse conditions. By using an integrated approach, we described in Chétoui olive cultivar the changes in plant growth, oxidative damage and osmolyte accumulation in leaves, in combination with corresponding changes in physiological parameters and proteome. Our results showed, under both stress conditions, a greater growth reduction of the aboveground plant organs than of the underground counterparts. This was associated with a reduction of all photosynthetic parameters, the integrity of photosystem II and leaf nitrogen content, and corresponding representation of photosynthetic apparatus proteins, Calvin-Benson cycle and nitrogen metabolism. The most significant changes were observed under the salinity stress condition. Oxidative stress was also observed, in particular, lipid peroxidation, which could be tentatively balanced by a concomitant photoprotective/antioxidative increase of carotenoid levels. At the same time, various compensative mechanisms to cope with nitrogen source demands and to control plant cell osmolarity were also shown by olive plants under these stresses. Taken together, these findings suggest that the Chétoui variety is moderately sensitive to both drought and salt stress, although it has greater ability to tolerate water depletion.

Quadrupole time-of-flight mass spectrometry analysis of glycerophospholipid molecular species in the two halophyte seed oils: Eryngium maritimum and Cakile maritima.

Future applications of lipids in clinical cohort studies demand detailed glycerophospholipid molecule information and the application of high-throughput lipidomics platforms. In the present work, a novel sensitive technique with high mass resolution and accuracy was applied to accomplish phospholipid analysis. Nanospray ionization quadrupole time-of-flight mass spectrometry was used to separate and quantify the glycerophospholipid classes as well as molecular species in two halophyte seed oils from Cakile maritima and Eryngium maritimum. Precursor or neutral loss scans of their polar head groups allowed the detection of molecular species within particular glycerophospholipid classes. Phosphatidylcholine was found to be the most abundant glycerophospholipid in both seed oils whereas phosphatidylethanolamine and phosphatidic acid were less abundant. Phosphatidylinositol, phosphatidylserine and phosphatidylglycerol were minor glycerophospholipids. Several molecular species within each class were detected and the main molecular species (C36:4, C36:3, C36:2, 34:2 and C34:1) were quantitatively different between the two halophytes and the different glycerophospholipids.

Comparative Ni tolerance and accumulation potentials between Mesembryanthemum crystallinum (halophyte) and Brassica juncea: Metal accumulation, nutrient status and photosynthetic activity.

Saline soils often constitute sites of accumulation of industrial and urban wastes contaminated by heavy metals. Halophytes, i.e. native salt-tolerant species, could be more suitable for heavy metal phytoextraction from saline areas than glycophytes, most frequently used so far. In the framework of this approach, we assess here the Ni phytoextraction potential in the halophyte Mesembryanthemum crystallinum compared with the model species Brassica juncea. Plants were hydroponically maintained for 21 days at 0, 25, 50, and 100µM NiCl2. Nickel addition significantly restricted the growth activity of both species, and to a higher extent in M. crystallinum, which did not, however, show Ni-related toxicity symptoms on leaves. Interestingly, photosynthesis activity, chlorophyll content and photosystem II integrity assessed by chlorophyll fluorescence were less impacted in Ni-treated M. crystallinum as compared to B. juncea. The plant mineral nutrition was differently affected by NiCl2 exposure depending on the element, the species investigated and even the organ. In both species, roots were the preferential sites of Ni(2+) accumulation, but the fraction translocated to shoots was higher in B. juncea than in M. crystallinum. The relatively good tolerance of M. crystallinum to Ni suggests that this halophyte species could be used in the phytoextraction of moderately polluted saline soils.

Effect of olive ripeness on chemical properties and phenolic composition of Chétoui virgin olive oil.

BACKGROUND: The aim of the present work was to investigate the influence of fruit ripening on oil quality in an attempt to establish an optimum harvesting time for Chétoui olives, the second main olive variety cultivated in Tunisia. RESULTS: Our results showed that many analytical parameters, i.e., peroxide value, UV absorbance at 232 and 270 nm, chlorophyll pigments, carotenoids and oleic acid contents decreased during ripening, whilst oil content and linolenic acid increased. Free acidity remained practically stable with a very slight rise at the highest maturity index. The trend of oxidative stability, total phenols and o-diphenols, showed an increase at the early stages followed by a reduction at more advanced stages of maturity. The major phenolic compounds, such as hydroxytyrosol, ligstroside aglycon, elenolic acid, acetoxy-pinoresinol and oleuropein aglycon, seemed to have the same behaviour. In the case of tyrosol, a strong decrease was observed directly related with the ripening progress. CONCLUSION: On the basis of the evolution of the analytical parameters studied, the best stage of Chétoui olive fruits for oil processing seems to be at ripeness index higher than 2.0 and lower than 3.0.

Changes in content and fatty acid profiles of total lipids of two halophytes: Sesuvium portulacastrum and Mesembryanthemum crystallinum under cadmium stress.

Changes in lipid content and fatty acid composition were determined in leaves of two halophytes: Sesuvium portulacastrum and Mesembryanthemum crystallinum exposed to cadmium (Cd). Experiments were carried out using young small-sized plants grown hydroponically (S. portulacastrum) or aseptically germinated seeds (M. crystallinum). Cd treatment was applied at different concentrations (0, 50, 100 and 200microM) for 30 days. At high cadmium doses (200microM), contents of total lipids (TL) and lipid fractions including galactolipids (GL), phospholipids (PL) and neutral lipids (NL) decreased more in M. crystallinum leaves than in S. portulacastrum leaves. Moreover, there were no significant changes in the total fatty acid composition of S. portulacastrum leaves during metal treatment. In contrast, M. crystallinum leaves showed a decrease in the percentage of the tri-unsaturated fatty acid (C18:3), and a corresponding increase in the percentage of di-unsaturated fatty acid (C18:2). These different responses suggested that S. portulacastrum seems to be more feasible for phytoremediation.

[Cadmium effects on lipid metabolism of rape (Brassica napus L.)]. / Effets du cadmium sur le métabolisme des lipides de plantules de colza (Brassica napus L.).

Treatment of rape seedlings with increasing CdCl2 concentrations in the culture medium resulted in a cadmium accumulation within plant tissues, which increased with external metal dose; such accumulation was more important in roots than in leaves. Biomass production was severely inhibited, even at low cadmium concentration. In leaves, quantities of chloroplastic lipids, monogalactosyldiacylglycerol (MGDG), digalactosyldiacylglycerol (DGDG), sulfolipids (SL) and phosphatidylglycerol (PG) decreased sharply under metallic treatment. However, contents of extrachloroplastic lipids, mainly phosphatidylcholine (PC) and phosphatidylethanolamine (PE) increased significantly. In contrast to leaves, contents of root phospholipids decreased. Likewise, levels of tri-unsaturated fatty acids: linolenic (C18:3) and hexadecatrienoïc (C16:3) dropped in leaves of treated seedlings as compared to those of controls, suggesting that heavy metals induced an alteration in the fatty acid desaturation process or a stimulation of their peroxidation. Also, trans palmitoleic acid (C16:1-trans) level in PG decreased considerably. In roots, there was a slight decrease in C18:3 level, with a concomitant increase in the C18:2 percentage. Radioactive labelling of leaf lipids with (1-14C) acetate allowed to show that fatty acid biosynthesis was noticeably altered at the highest cadmium dose used (50 microM). Biosynthesis of tri-unsaturated fatty acids was also inhibited which may explain the decline in non-labelled lipid contents. Results showed that metallic ion seems to affect selectively chloroplastic membranes due to an inhibition of polyunsaturated fatty acid biosynthesis. Moreover, a lipid peroxidation occurred in our case because of the spectacular increase of malondialdehyde (MDA) content observed in cadmium treated leaves.

Changes in content and fatty acid profiles of total lipids and sulfolipids in the halophyte Crithmum maritimum under salt stress.

In the halophyte Crithmum maritimum, the sulfolipid content increased considerably in the presence of NaCl. There were no significant changes in the total fatty acid composition of sulfolipids during salt treatment, except for linoleic and linolenic acids. In comparison to the control plants, sulfolipids in NaCl-treated plants showed a decrease in the percentage of unsaturated fatty acid (C18:3), and a corresponding increase in the percentage of unsaturated fatty acids (C18:2). As a whole, the data reported in this work suggest that sulfolipds may be one important aspect of strategies involved in salt tolerance of this halophyte.