Background/Aim: Sweet almond (Prunus amygdalus dulcis) oil is one of the most famous cold-pressed seed oils. However, other species of Prunus can provide oils with healthy properties. We analyzed the fatty acid (FA) composition, as well as the antioxidant, the in vitro anti-inflammatory properties, and the antibiofilm activity of five commercial vegetable cold-pressed seed oils of apricot, peach, plum, cherry, and black cherry.Methods: Gas Chromatography-Mass Spectrometry was performed for the analysis of FAs The antioxidant property of the oils was carried using different tests [2, 2-diphenyl-1-picrylhydrazyl (DPPH assay)], Ferric Reducing Antioxidant Power (FRAP), and the 2, 20 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+). The denaturation assay performed on bovine serum albumin (BSA) was used to evaluate the in vitro anti-inflammatory activity. The anti-biofilm activity was assessed using five pathogenic strains, namely, Acinetobacter baumannii, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Staphylococcus aureus, through the crystal violet test and the 3-(4,5-dimethylthiazol-2-yl)−2,5-diphenyltetrazolium bromide (MTT), used to evaluate the metabolism of the microbial cells present within the biofilm.Results: Oleic acid and linoleic acids were the most abundant FAs. Black cherry seed oil exhibited the best antioxidant activity, but in general, the amount of oil needed to inhibit the activity of 1 ml of DPPH assay at 50% did not exceed 10 μg. The extract concentration for the 50% inhibition of the denaturation of the protein (IC50) did not exceed 4.4 μg. Linoleic and stearic acids affected the antioxidant activity of the oils; oleic acid, linolenic, and palmitoleic acids exhibited beneficial effects in preserving the BSA denaturation, as shown by the correlation data. The oils were able to inhibit the biofilm formation of the pathogens (up to 71.40% of inhibition) as well as act against their mature biofilm, although with different strengths, with values up to 61.54%. Concurrently, they also acted on the pathogen metabolism.Conclusion: The oils represent a valuable source of some healthy FAs. They showed potential antioxidant and anti-inflammatory in vitro activity, in addition, their potential effect on the biofilm can offer important ideas for research and reflection on their use as functional foods and/or ingredients.

Oregano (Origanum vulgare L.) is mainly cultivated, both as fresh and dried herb, for several purposes, such as ailments, drugs, and spices. To evaluate the influence of some drying methods on the chemical composition of the essential oil of oregano, its aerial parts were dehydrated by convective drying techniques (shade, static oven), microwave-assisted heating (three different treatments) and osmotic treatment. The oils were analyzed by GC-FID and GC–MS. The highest essential oil yield was achieved from microwave and shade drying methods. In total, 39 components were found, with carvacrol (ranging from 56.2 to 81.4%) being the main constituent; other compounds present in lower amounts were p-cymene (1.6–17.7%), γ-terpinene (0.8–14.2%), α-pinene (0.1–2.1%), thymol methyl ether (0.4–1.8%) and thimoquinone (0.5–3.5%). The essential oil yields varied among the different treatments as well as the relative compositions. The percentages of p-cymene, γ-terpinene and α-pinene decreased significantly in the dried sample compared with the fresh sample; on the other hand, carvacrol, isoborneol and linalool increased significantly in the dried materials. The choice of the drying method for obtaining the essential oil therefore appears crucial not only in relation to the higher yield but also and above all in reference to the percentage presence of components that can direct the essential oil toward an appropriate use.

Many natural-derived compounds, including the essential oils from plants, are investigated to find new potential protective agents in several neurodegenerative disorders such as Alzheimer’s disease (AD). In the present study, we tested the neuroprotective effect of limonene, one of the main components of the genus Citrus, against the neurotoxicity elicited by Aβ_1-42 oligomers, currently considered a triggering factor in AD. To this aim, we assessed the acetylcholinesterase activity by Ellman’s colorimetric method, the mitochondrial dehydrogenase activity by MTT assay, the nuclear morphology by Hoechst 33258, the generation of reactive oxygen species (ROS) by DCFH-DA fluorescent dye, and the electrophysiological activity of K_V3.4 potassium channel subunits by patch-clamp electrophysiology. Interestingly, the monoterpene limonene showed a specific activity against acetylcholinesterase with an IC₅₀ almost comparable to that of galantamine, used as positive control. Moreover, at the concentration of 10 µg/mL, limonene counteracted the increase of ROS production triggered by Aβ_1-42 oligomers, thus preventing the upregulation of K_V3.4 activity. This, in turn, prevented cell death in primary cortical neurons, showing an interesting neuroprotective profile against Aβ_1-42-induced toxicity. Collectively, the present results showed that the antioxidant properties of the main component of the genus Citrus, limonene, may be useful to prevent neuronal suffering induced by Aβ_1-42 oligomers preventing the hyperactivity of K_V3.4.

Several researchers have demonstrated the health and pharmacological properties of carvacrol and p-cymene, monoterpenes of aromatic plants. This study investigated these compounds’ possible anti-cholinesterase, anti-α-amylase, and neuroprotective effects. We evaluated the anti-acetylcholinesterase and anti-α-amylase activities at different concentrations of the compounds. The maximum non-toxic dose of carvacrol and p-cymene against SH-SY5Y neuroblastoma cells was determined using an MTT assay. The neuroprotective effects of the compounds were evaluated on H₂O₂-induced stress in SH-SY5Y cells, studying the expression of caspase-3 using Western blotting assays. Carvacrol showed inhibitory activities against acetylcholinesterase (IC50 = 3.8 µg/mL) and butyrylcholinesterase (IC₅₀ = 32.7 µg/mL). Instead, the anti-α-amylase activity of carvacrol resulted in an IC₅₀ value of 171.2 μg/mL After a pre-treatment with the maximum non-toxic dose of carvacrol and p-cymene, the expression of caspase-3 was reduced compared to cells treated with H₂O₂ alone. Carvacrol and p-cymene showed in vitro anti-enzymatic properties, and may act as neuroprotective agents against oxidative stress. Further studies are necessary to elucidate their possible use as coadjutants in preventing and treating AD in diabetic patients.

Background: The potential of essential oils (EOs) and of their principal constituents for eradication of biofilm and at the same time the research of new potential acetylcholinesterase inhibitors is gaining increasing interest in last years. The aims of this study were to determine the chemical composition and to evaluate the antibacterial, cytotoxic, and anti-acetylcholinesterase properties of Myrtus communis leaves essential oil and its main constituents. Methods: Essential oil was obtained by hydrodistillation of M. communis L. leaves and was analyzed by GC and GC–MS. The antimicrobial activity was carried out against both gram-negative and gram-positive bacteria. The microdilution method was used to estimate the minimum inhibitory concentrations (MICs). Then, the capacity of essential oil and its main constituent to inhibit biofilm growth, with the method of O’Toole and Kolterand, and the metabolic activity of biofilm cells through the MTT colorimetric method were evaluated at different times. Moreover, was studied the potential cytotoxic activity against SH-SY5Y cell line with MTT assay and the anti-acetylcholinesterase activity using Ellman’s assay. Results: Myrtenyl-acetate, 1,8 cineole, α-pinene, and linalool were the main components in the EO. The myrtle EO, at the minimum tested dose (0.4 mg/ml), inhibited S. aureus biofilm by 42.1% and was capable of inhibiting the biofilm cell metabolism in all tested strains, except Staphylococcus aureus. Moreover, the EO showed good cytotoxic and anti-acetylcholinesterase activities IC₅₀ of 209.1 and 32.8 μg/ml, respectively. Conclusions: The results suggest that myrtle EO and its main constituents could be used as possible products that could act against the resistant pathogenic species E. coli, P. aeruginosa, L. monocytogenes and S. aureus, on the other hand, as possible coadjutants in the treatment of neurological diseases.

Rosmarinus officinalis L. is an aromatic evergreen plant from the Lamiaceae family. The purpose of this study was to compare the chemical profile and bioactivities of hydroalcoholic extracts derived from wild and cultivated R. officinalis. The chemical composition of the extracts was evaluated via LC–MS analysis, which revealed the presence of a wide range of phenolic compounds, including flavonoids, phenolic and terpenes. Both extracts showed a similar interesting antioxidant activity, probably related to their content of phenol and flavonoids. The analysis of anti-acetylcholinesterase (AChE), anti-butyrylcholinesterase (BChE), and anti-α-amylase activities showed analogous inhibition, except for AChE, in which the wild type was more active than the cultivated one. Finally, in vitro studies were performed using the J774A.1 murine macrophage cell line, to characterize the anti-inflammatory and the antioxidant effects of the extracts. As expected, pretreatment with the extracts significantly reduced the production proinflammatory cytokines and ROS through modulation of the nitric oxide pathway and the mitochondrial activity. Importantly, it is observed that the anti-inflammatory effect of the extracts was explicated through the inhibition of NF-kB and its downstream mediator COX-2. Collectively, these results demonstrated that these extracts could represent a starting point for developing novel therapeutic strategies for the treatment of inflammation-based diseases. Moreover, since no significant changes were observed in terms of composition and activity, both wild and cultivated R. officinalis extracts can be recommended for food and pharmaceutical purposes.