Panayiota Piri

The Mediterranean basin is a global biodiversity hotspot characterized by a high frequency of halophytic flora, which have evolved specialized metabolic adaptations to thrive under hypersaline, drought, and high-UV conditions. These physiological mechanisms facilitate the biosynthesis of diverse secondary metabolites, which have garnered significant attention for their antimicrobial and antifungal properties. This review critically evaluates the antimicrobial potential of nine prominent Mediterranean halophytes, namely Cakile maritima, Crithmum maritimum, Eryngium maritimum, Juncus acutus, Juncus maritimus, Limbarda crithmoides, Otanthus maritimus, Pancratium maritimum, and Salicornia europaea, synthesizing data on their phytochemical profiles and efficacy against foodborne, clinical, and agricultural pathogens. The findings indicate that several extracts and essential oils exhibit potent inhibitory effects, with minimum inhibitory concentration (MIC) values often comparable to or even lower than those of established antibiotics, notably against Staphylococcus spp., Salmonella spp., and various Candida species. These halophyte extracts are also used successfully to control microbial contamination in the production of plant- and animal-based foods. Despite the significant potential for agricultural and food sectors, full commercialization requires addressing challenges related to field-level efficacy, formulation stability, and comprehensive toxicological safety. Overall, this study underlines the role of Mediterranean halophytes as resilient bio-factories capable of providing sustainable, natural solutions to pressing antimicrobial resistance and food security challenges.

The present study investigated the use of natural deep eutectic solvents (NaDESs) combined with ultrasound-assisted extraction (UAE) for the efficient recovery of anthocyanins and antioxidant phenolics from Damask rose (DR). A wide range of environmentally friendly solvents was screened, and choline chloride–propylene glycol (ChCl-PG) was identified as the most effective extraction medium. The extraction conditions were optimized using response surface methodology (RSM) and artificial neural network (ANN) models to maximize anthocyanin and phenolic contents, as well as antioxidant activity. Under the optimal parameters, the DR extracts exhibited relatively high levels of bioactive compounds, including total anthocyanin content of 5.2–5.3 mg cyanidin-3-glucoside equivalents g⁻¹ sample, total phenolic content of 63.4–64.2 mg gallic acid equivalents g⁻¹ sample, along with substantial antioxidant potential (DPPH: 68.2–68.8% inhibition, FRAP: 581.6–591.9 μmol Trolox equivalents g⁻¹ sample). Chromatographic analysis of the optimum extract revealed cyanidin as the predominant anthocyanidin in DR, and its stability was further evaluated, revealing improved preservation under dark conditions at lower temperatures over a 15-day storage period. Moreover, the IC₅₀ values confirmed antimicrobial effects against the tested foodborne pathogens. Furthermore, the inhibitory effect of the DR extract remained stable against S. aureus and S. cerevisiae throughout the storage period. Overall, the findings demonstrate that NaDES-UAE is a promising and sustainable approach for obtaining anthocyanin-rich DR extracts with antioxidant and antimicrobial potential.

This study optimized cold‐ and hot‐water extraction methods for Cistus salviifolius aerial parts using response surface methodology, based on three‐level and three‐factor Box–Behnken design, to maximize phenolic content and antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa . The optimization process systematically evaluated the effects of extraction time, temperature, and water‐to‐plant material ratio on total phenolic, flavonoid, and tannin content, as well as bacterial growth inhibition. The extraction method critically influenced the resulting phytochemical profiles. Hot‐water extract demonstrated superior efficiency for overall polyphenol recovery, characterized by a higher flavonol content likely derived from the thermal hydrolysis of ellagitannins. Conversely, cold‐water extract yielded a distinct chemical profile rich in ellagitannin isomers, including punicalagin and cistusin. These compositional variations led to divergent antibacterial efficacies; hot‐water extract was more potent against P. aeruginosa , whereas cold‐water extract exhibited superior bactericidal activity against S. aureus . Significantly, cold‐water extract displayed a remarkable, previously undocumented capacity to disaggregate mature biofilms. The study concludes that while hot water extraction offers a more comprehensive recovery of bioactive compounds, cold‐water extraction can be specifically tailored to yield extracts with potent, targeted activity against S. aureus and its biofilms, highlighting the importance of selecting the appropriate extraction method for desired therapeutic outcomes.