Pistacia lentiscus, Rosmarinus officinalis, Erica multiflora, Calicotome villosa, and Phillyrea latifolia were considered important medicinal herbs and were used to treat various ailments. The present study was designed to evaluate the antioxidant and antimicrobial activities of ethanolic extracts (EEs). P. lentiscus and R. officinalis were the richest species in phenolic compounds. Similarly, both species showed the highest values of flavonoids. While the EEs of P. lentiscus, E. multiflora, and C. villosa had higher amounts of tannins. These phenolic compounds were evaluated by two different tests, namely diphenyl picrylhydrazyl (DPPH) and ferric iron-reducing power (FRAP). The IC50 values were found to be significant (p < 0.05) for P. lentiscus and E. multiflora. Similarly, both plants showed the highest ferric-reducing antioxidant power (FRAP). This study has been conducted to evaluate the antibacterial potential of EEs against selected bacteria—Gram-positive bacteria (Staphylococcus aureus ATCC 29213, Listeria monocytogenes ATCC 7644) and Gram-negative bacteria (Escherichia coli ATCC 8739, Salmonella typhimurium NCTC 6017)—and determine their modes of action. The ethanolic extracts inhibited bacterial growth by producing concentration-dependent zones of inhibition. Treatment with these extracts at their minimum inhibitory concentrations (MICs) showed a significant reduction (p < 0.05) in the viability of bacteria. The extracts did not induce total lysis. Bacteria organisms treated with EEs at MICs showed a significant (p < 0.05) loss of tolerance to NaCl (5%). Our results highlighted the use of plant extracts as natural antibacterials that can be safely used in health care and led to the understanding of the antibacterial mechanism of plant extracts.
15 October 2022 in International Journal of Environmental Health Research
This study was designed to evaluate the antioxidant and antimicrobial activity of ethanolic extracts (EEs) of Cistus monspeliensis and Globularia alypum. C. monspeliensis showed the highest values of phenolic compounds. Further, it was shown that EE of C. monspeliensis displayed the highest DPPH (IC50 = 8.3 ± 1.08 mg/mL). The chemical profiles demonstrated a total of 12 and 13 phenolic compounds for C. monspeliensis and G. alypum, respectively. EEs of both plants possessed broad-spectrum antimicrobial activity when tested against Escherichia coli and Staphylococcus aureus. Treatment of studied strains with these extracts at their MICs reduced considerably the bacterial viability. The extracts did not induce total bacterial lysis, as determined by the measurement of optical density at 620 nm. Strains treated with EEs at Minimum Inhibitory Concentrations showed significant loss of tolerance to NaCl. Our results contribute to understanding the antibacterial mechanism of ethanolic extracts of the studied medicinal plants.
In this work, a rapid, precise, and cost-valuable method has been established to quantify phenolic compounds in olive oil using new-based hydrophilic interaction solid-phase extraction (SPE). Boehlert’s experimental design applied the determination of the optimal operating conditions. An investigation into the effects of the methanol composition (50–100%), the volume of eluent (1–12 mL), and pH (1–3) on the extraction of phenols acids and total phenols from Tunisian olive oils was performed. The results showed that the extraction conditions had a significant effect on the extraction efficiency. The experiment showed that the greatest conditions for the SPE of phenolic acids were the methanol composition at 90.3%, pH at 2.9, and volume at 7.5 mL, respectively. The optimal conditions were applied to different types of olive oils, and it could be concluded that larger concentrations of polyphenols were found in extra virgin olive oil (89.15–218), whereas the lowest levels of these compounds (66.8 and 5.1) were found in cold-pressed crude olive oil and olive pomace oil, respectively.
Understanding the functioning of shrub species during dry periods is necessary to forecast ecosystem responses to future climates, particularly in Mediterranean environments. We evaluated the seasonal changes in leaf gas exchange, hydraulic traits, carbon and nitrogen isotopes, and non-structural carbohydrates of seeders and resprouting shrub species typical of Aleppo pine forests across an aridity gradient in Tunisia: Djebel Zaghouan (subhumid climate), Djebel Mansour (semiarid transitional climate), and Djebel El Sarj (semi-arid climate). We monitored seven woody species: Pistacia lentiscus, Erica multiflora, Phillyrea latifolia (resprouters), Cistus monspeliensis, Rosmarinus officinalis (seeders), Globularia alypum, and Calicotome villosa (resprouters-seeders). The seasonal variation in leaf water content was usually higher in seeders than in resprouters and was associated with higher resistance to embolism. In contrast, the seasonal variation in non-structural carbohydrates was higher in resprouters, especially at the driest site. Both δ13C and δ15N displayed seasonal enrichment-depletion patterns, with seeders showing an overall higher δ13C in summer than in spring, consistent with a water-saving strategy of increasing water use efficiency. Discriminant analysis suggested that resprouters can sustain a positive carbon balance during drought periods. The differential impact of summer droughts on water status and the ecophysiology of these plant strategies may lead to different ecosystem dynamics depending on whether climate change tips the balance towards a preponderance of stressors (drought) or disturbances (fire) in dry Mediterranean areas.
Oxidative stress, resulting from an imbalance between free radical production and antioxidant defenses, can negatively impact animal health, welfare, and productivity. In livestock, diseases are often correlated with reduced antioxidant status. To mitigate oxidative stress, natural antioxidants have gained attention as alternatives to synthetic compounds. The growing need for safe and natural animal products has led to the increased use of plant food additives (PFAs) as antioxidants in animal feed. These natural sources include plant extracts, essential oils, and bioactive compounds-rich by-products. Such antioxidants can enhance product quality, oxidative stability, and shelf life in ruminants, swine, and rabbits. Additionally, maintaining a good antioxidant status positively affects meat quality parameters, including vitamin E content and reduced lipid peroxidation. This review explores the properties of natural antioxidants, extraction methods, and their significance in promoting animal welfare, performance, and product quality.
Background As part of global climate change, variation in precipitation in arid ecosystems is leading to plant adaptation in water-use strategies; significant interspecific differences in ecophysiological response will change the plant behavior. The mainaim of this study was to investigate the ecophysiological responses of Phillyrea latifolia species to seasonal drought stress. Measurements were conducted between March and December 2018. The parameters studied were the Leaf Water Potential (ψ leaf ), Net photosynthesis (Pn), stomatal conductance (gs) and leaf transpiration (Tr), maximum efficiency of PSII photochemistry (Fv/ Fm), and Hydraulic conductivity. Main results The results showed that all measured parameters varied significantly with the season(P <.0001). The results of ψ leaf showed the highest average in summer (−2.99±0.08 MPa). Likewise, the highest values of the maximal photochemical efficiency of PSII (Fv/Fm) were observed in summer (0.83±0.06). However, the highest values of Pn (3.62±0.41 µmol m -2 s -1 )and Tr (0.3±0.028 µmol m -2 s -1 ) were noted in autumn. The Initial Hydraulic Conductivity ( K in ) value was in spring (1.34 -04 ±110 -5 mmol s -1 m -2 MPa -1 ) and autumn (1.1810 -04 ±2.3010 -6 mmol s -1 m -2 MPa -1 ) and the Maximal Hydraulic Conductivity ( K max ) was the highest during the spring season (3.4510 -04 ±2.7010 -11 mmol s -1 m -2 MPa -1 ). The results of the Stomatal Conductance (gs)were showed that the lowest values were recorded in summer (0.19±0.04 MPa). The percentage of loss conductivity (PLC) reached 66%. During the spring season, the soil had a decreasing moisture profile as it moved to the depths and varied from 15.23±5.48% at 20cm to 6.26±2.46% at 80 cm. Conclusions The best physiological performances of Phillyrea latifolia reported in spring and autumn may be attributed to favorable environmental conditions. The answers depend not only on the specie but also on the climates in which they grow.