Comparison of chemical composition and antioxidant activities of two Winter savory subspecies (Satureja montana subsp. variegata and Satureja montana subsp. montana) cultivated in Northern Italy

Harnessing Essential Oils for Acetylcholinesterase Inhibition: A Literature Review

Aromatherapy, a branch of herbal and alternative medicine, has emerged as a promising non-pharmacological approach to treating Alzheimer's disease (AD) due to its potential to enhance cognitive function. This comprehensive review evaluates the inhibitory effects of various plant essential oils (EOs) on acetylcholinesterase (AChE) activity, a key enzyme implicated in the pathophysiology of AD. Our analysis highlights EOs from the Lamiaceae family, particularly rosemary (Salvia rosmarinus) and lavender (Lavandula officinalis), which demonstrated the most potent AChE inhibitory effects. Key chemical constituents such as α- and β-pinene, limonene, linalool, 1,8-cineole, caryophyllene, estragole, eugenol, and asarone were identified as the primary active components responsible for these effects. Additionally, we discuss the biochemical mechanisms underlying the neuroprotective properties of these EOs and their potential role in developing effective therapies for AD. Our findings underscore the therapeutic promise of specific EOs and their constituents in managing cognitive decline associated with neurodegenerative disorders.

Chemical Composition and Antifungal Effect of the Essential Oils of Thymus vulgaris L., Origanum vulgare L., and Satureja montana L. Against Clinical Isolates of Candida spp

Infections caused by Candida species are on the rise, and the escalating concern revolves around the growing resistance to known antifungals, particularly in immunocompromised individuals. The essential oils (EOs) of thyme, oregano, and savory were studied for antifungal, antibiofilm, and potential synergistic activity against isolates of Candida. The oils underwent chemical characterization, revealing comparable compositions of the monoterpene phenols, predominantly thymol and carvacrol, albeit in varying proportions. Anti-Candida activity assessments of these EOs and the type of interactions among these agents on planktonic cells of candidal isolates were done by microdilution and the checkerboard method, respectively. Our findings underscore the significant inhibitory effects of the tested agents against both planktonic and biofilm forms of Candida cells. The minimum inhibitory concentration (MIC) values of the tested oils against planktonic Candida cells ranged from 0.312 to 2.500 mg/mL, classifying them as highly to moderately active against the causative agents of candidosis. The effect on the formation of Candida biofilms was statistically significant for the majority of the tested candidal isolates, with a reduction percentage greater than 50%. Notably, the high significance of our study lies in the presented synergistic effects observed in the majority of the examined combinations, without any presence of antagonistic interactions.

GC-MS Analysis of Polysaccharides from an Intergeneric Hybrid of Pleurotus florida and Cordyceps militaris: A Comparative Study

Edible and medicinal mushrooms are valuable sources of polysaccharides, known for their dual roles as immunostimulants and immunosuppressants. This study aimed to enhance polysaccharide content by fusing two mushroom species, P. florida and C. militaris, while exploring their antioxidant and antibacterial potential. These mushrooms have diverse health benefits, including lowering high cholesterol, providing anti-inflammatory effects, supporting diabetes management, aiding in cancer treatment, and enhancing the efficacy of COVID-19 vaccines. Successful hyphal fusion was achieved, and optimal culture conditions were determined using response surface methodology. The hybrids exhibited superior growth compared to the parental strains. Hyphal fusion improved several attributes, resulting in diverse hybrids with increased biomass and metabolite production. FTIR analysis confirmed the presence of exopolysaccharides, with concentrations measured at 28.4 g/L (P1), 31.50 g/L (CD), and 36.74 g/L (F3). GC-MS analysis identified various bioactive metabolites, including a higher concentration of dimethyl palmitamine in the hybrid, a novel compound, butanenitrile, 2-(methoxymethoxy), which was not found in the parental strains. These compounds are likely responsible for the enhanced antimicrobial and antioxidant activities.

Essential Oils of Two Subspecies of Satureja montana L. against Gastrointestinal Parasite Anisakis simplex and Acetylcholinesterase Inhibition

The increasing presence of Anisakis spp. in fish is having significant implications for public health due to a rise in cases of anisakiasis. Given this situation, there is a critical need to develop new strategies to fight this parasite. Satureja montana L., commonly known as savory, is a plant recognized in folk medicine for its therapeutic activity, such as being antispasmodic and digestive, among other properties. The aim of this study was to assess the nematicide activity against A. simplex larvae of the essential oil from two varieties of S. montana (subsp. montana (SMM) and variegata (SMV)). The essential oils were obtained via hydro-distillation of the flowering aerial parts. In vitro assays demonstrated the complete inactivation of anisakis larvae after 24 h when exposed to both essential oils, along with a significant reduction in their penetration capacity. Moreover, both essential oils showed an inhibitory effect on acetylcholinesterase (AChE). No differences between the subspecies were observed in any of the assays. Hence, the nematicidal activity of essential oils could be attributed to their capacity to inhibit AChE. These findings suggest the potential of S. montana essential oil for therapeutic and food industry applications.

Satureja montana and Mentha pulegium essential oils' antimicrobial properties against Pseudomonas syringae pv. actinidiae and elicitor potential through the modulation of kiwifruit hormonal defenses

Pseudomonas syringae pv. actinidiae (Psa) is responsible for the kiwifruit bacterial canker, the most severe disease of Actinidia spp. The use in agriculture of antibiotics and cooper-based compounds is increasingly being restricted, demanding for new sustainable alternatives to current agrochemicals. We aimed to characterize the anti-Psa potential of essential oils (EOs) of Mentha pulegium and Satureja montana and investigate if they elicit the plant-host hormonal defenses. The EOs were characterized through gas-chromatography with flame ionization detector (GC-FID) and mass spectrometry (MS). Pulegone (78.6%) and carvacrol (43.5%) were the major constituents of M. pulegium and S. montana EO, respectively. Only S. montana EO showed relevant anti-Psa activity in vitro. To evaluate if the EOs also elicited host defenses, in vitro shoots were treated with 2 mg shoot-1 of EO-solution and subsequently inoculated with Psa three days later. Shoots were analyzed 10 min, three days (and 10 min after Psa-inoculation), four and ten days after EO application. The up/down regulation of RNA-transcripts for hormone biosynthesis, Psa biofilm production and virulence genes were quantified by real-time quantitative PCR (RT-qPCR). Phytohormones were quantified by High-Performance Liquid Chromatography (HPLC). S. montana EO showed the most promising results as a defense elicitor, increasing 6-benzylaminopurine (BAP) by 131.07% and reducing indole-3-acetic acid (IAA) levels by 49.19%. Decreases of salicylic acid (SA), and gibberellic acid 3 (GA3) levels by 32.55% and 33.09% respectively and an increase of abscisic acid (ABA) by 85.03%, in M. pulegium EO-treated shoots, revealed some protective post-infection effect. This is the most comprehensive research on the Psa's impact on phytohormones. It also unveils the protective influence of prior EO exposure, clarifying the plant hormonal response to subsequent infections. The results reinforce the hypothesis that carvacrol-rich S. montana EO can be a suitable disease control agent against Psa infection. Its dual action against pathogens and elicitation of host plant defenses make it a promising candidate for incorporation into environmentally friendly disease management approaches. Nonetheless, to fully leverage these promising results, further research is imperative to elucidate the EO mode of action and evaluate the long-term efficacy of this approach.

Use of Essential Oil Emulsions to Control Escherichia coli O157:H7 in the Postharvest Washing of Lettuce

Essential oils (EOs) have strong antibacterial properties and can be potential sanitizers to reduce pathogen load and prevent cross-contamination during postharvest washing. The objective of this study was to investigate the efficacy of emulsions containing oregano (OR; Origanum vulgare) and winter savory (WS; Satureja montana) EOs at different concentrations (0.94 and 1.88 µL/mL) and storage times (0 h, 24 h, and 7 days), in reducing Escherichia coli O157:H7 on the surface of three types of lettuce (romaine, crisphead, and butterhead). The EO emulsions were compared with one no-rinse treatment and three rinse treatments using water, 200 ppm chlorine, and 80 ppm peroxyacetic acid (PAA), respectively, in a simulated washing system. The results showed that while the EO emulsions significantly reduced E. coli O157:H7 on crisphead lettuce over time, not all treatments were effective for romaine and butterhead lettuce. The mixture of OR and WS at concentrations of 0.94 and 1.88 µL/mL was found to be the most effective in reducing E. coli O157:H7 on inoculated lettuce, resulting in reductions of 3.52 and 3.41 log CFU/g, respectively. Furthermore, the PAA and the mixture of OR and WS at 1.88 µL/mL effectively limited bacterial cross-contamination close to the detection limit for all lettuce types during all storage times. These results suggest that OR and WS EOs could serve as potential alternatives to chemical sanitizers for postharvest lettuce washing.

Antibiotic properties of Satureja montana L. hydrolate in bacteria and fungus of clinical interest and its impact in non-target environmental microorganisms

The aim of this study was to analyse the microbicidal and microbiostatic activity of S. montana hydrolate L., the water-soluble fraction of the hydro-distillation process used to obtain the essential oil, on 14 Gram-positive and Gram-negative bacteria and a fungus of clinical interest. To consider whether this hydrolate is a more environmentally friendly alternative to traditional antibiotics, its effect on non-target microorganisms in the aquatic and terrestrial environment was analysed using natural soil and river microorganism communities, characterized through 16S rRNA gene sequencing. Results showed that S. montana hydrolate was especially effective (25% v/v concentration) against Pasteurella aerogenes, Streptococcus agalactiae and Acinetobacter baumannii (priority 1, WHO). It was also a microbicide for a further 7 bacterial strains and the fungus Candida albicans (50% v/v concentration). The river and soil communities exposed to the hydrolate showed a decrease in their growth, as well as a decrease in their ability to metabolize polymers and carbohydrates (soil microorganisms) and polymers, carboxylic and ketone acids (river microorganisms). Hydrolates could be an alternative to conventional antibiotics, but their impact on the environment must be taken into account.

Variability in Biological Activities of Satureja montana Subsp. montana and Subsp. variegata Based on Different Extraction Methods

Winter savory (Satureja montana L.) is a well-known spice and medicinal plant with a wide range of activities and applications. Two subspecies of S. montana, subsp. montana and subsp. variegata, were used for the preparation of seven different extracts: steam distillation (essential oil (EO) and hydrolate (HY)), subcritical water (SWE), ultrasound-assisted (UAE-MeOH and UAE-H2O), and microwave-assisted (MAE-MeOH and MAE-H2O) extraction. The obtained EOs, HYs, and extracts were used for an in vitro evaluation of the antioxidant activity (DPPH, ABTS, reducing power, and superoxide anion methods) and in vitro antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella Typhimurium, Saccharomyces cerevisiae, and Candida albicans. The antimicrobial screening was conducted using disk-diffusion assessment, minimal inhibitory concentration, time-kill kinetics modeling, and pharmacodynamic study of the biocide effect. The total phenolic content (TPC) was highest in EO, followed by SWE, MAE, and UAE, and the lowest was in HY. The highest antimicrobial activity shows EO and SWE for both varieties, while different UAE and MAE extracts have not exhibited antimicrobial activity. The natural antimicrobials in the S. montana extract samples obtained by green extraction methods, indicated the possibility of ecologically and economically better solutions for future in vivo application of the selected plant subspecies.

HIV-1-RT inhibition activity of Satureja spicigera (C.KOCH) BOISS. Aqueous extract and docking studies of phenolic compounds identified by RP-HPLC-DAD

AIDS is a global disease caused by HIV, affecting millions of people and causing death. The current limitations of antiretroviral therapy used in the therapy of HIV/AIDS have led to the need to search for new and effective drugs from natural products, especially plants. Herewith, using the present study, the detection of HIV-1-RT inhibition of aqueous extract of Satureja spicigera (C.KOCH) BOISS. was performed for the first time. Besides, total phenolic content (TPC), analysis of phenolic constituents by RP-HPLC-DAD and antioxidant capacity by DPPH and Ferric reducing antioxidant power (FRAP) methods were determined for the first time. In addition, molecular docking studies were carried out between HIV-1-RT and phenolic substances, the presence of which was determined in the aqueous extract, for the determination of the phenolics that may be responsible for HIV-1-RT activity. HIV-1-RT inhibition was defined as IC₅₀ : 22.83 μg/ml. Benzoic acid, vanillin, rutin, and chlorogenic acid were present as main phenolics in quantities of 621.96, 505.87, 349.33, and 323.23 µg phenolic/g extract, respectively. Further, TPC, DPPH, and FRAP were calculated as in the order of 151.69 mg GAE/g extract, 23.77 µg/ml, and 445.7 µmol TE/g extract. Chlorogenic acid (-8.48 kcal/mol) was found to be the most effective ligand in docking studies, with a value close to positive standard nevirapine (-9.35 kcal/mol). Hereby, although the aqueous extract of S. spicigera can be used as a natural antioxidant, the crude extract or its phenolics have the potential to be used in the treatment of AIDS due to its high HIV-1-RT activity. PRACTICAL APPLICATIONS: In this study, anti-HIV-1-RT and antioxidant activity and total phenolic content of Satureja spicigera aqueous extract were determined. In addition, HPLC analysis of some phytochemicals and the activities of these phytochemicals against HIV-1-RT enzyme was determined by molecular docking studies. The results showed that the aqueous extract of S. spicigera and some of the phytochemicals it contains have the potential to be used as a natural product against HIV infection or in the treatment of AIDS.

Evaluation of the in vitro antibacterial activity of some essential oils and their blends against Staphylococcus spp. isolated from episodes of sheep mastitis

Staphylococcus aureus and coagulase-negative staphylococci are among the major causes of mastitis in sheep. The main goal of this research was to determine the in vitro antibacterial activity of several essential oils (EOs, n 30), then five of them were chosen and tested alone and in blends against staphylococci isolates. Five bacteria were isolated from episodes of ovine mastitis (two S. aureus and three S. xylosus). Biochemical and molecular methods were employed to identify the isolates and disk diffusion method was performed to determine their antimicrobial-resistance profile. The relative percentage of the main constituents in the tested essential oils and their blends was detected by GC-EIMS analysis. Antibacterial and bactericidal effectiveness of essential oils and blends were evaluated through minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). All of them showed sensitivity to the used antimicrobials. The EOs with the highest antibacterial activity were those belonging to the Lamiaceae family characterized by high concentrations of thymol, carvacrol and its precursor p-cymene, together with cinnamon EO, rich in cinnamaldehyde. In terms of both MIC and MBC values, the blend composed by Thymus capitatus EO 40%, Cinnamomum zeylanicum EO 20%, Thymus serpyllum EO 20% and Satureja montana EO 20% was found to be the most effective against all the isolates. Some essential oils appear to represent, at least in vitro, a valid tool against ovine mastitis pathogens. Some blends showed a remarkable effectiveness than the single oils, highlighting a synergistic effect in relation to the phytocomplex.

Nutritional value and biological properties of Chilean wild and commercial edible mushrooms

The nutritional value and biological properties of 24 samples of Chilean edible mushrooms were evaluated. The nutritional value was determined by measuring moisture, protein, fat, ash and carbohydrate contents. The biological activity was determined by using antibacterial, antifungal and antioxidant tests. The mushrooms showed high total carbohydrate (83.65-62.97 g/100 g dw) and crude protein (23.88-8.56 g/100 g dw) contents, but low fat contents (6.09-1.05 g/100 g dw). Ch₂Cl₂-extracts were more active against bacteria and fungi than MeOH-extracts. Ch₂Cl₂-extracts of B. loyo, C. lebre, L. edodes, M. conica and R. flava inhibited the growth of Gram-positive bacteria. The Ch₂Cl₂-extracts of A. cylindracea, B. loyo, and G. gargal showed strong effects against fungi. R. flava showed the highest phenolic content and antioxidant activity. The Chilean species B. loyo, C. lebre and G. gargal exhibited interesting nutritional value and biological properties, showing potential to be used as a dietary nutritional supplement.

Ecological and Plant Community Implication on Essential Oils Composition in Useful Wild Officinal Species: A Pilot Case Study in Apulia (Italy)

The study focused on the effects of ecology (plant communities and topographical data) on composition of essential oils (EOs) of some officinal wild plant species (Lamiales): Clinopodium suaveolens, Salvia fruticosa subsp. thomasii, Satureja montana subsp. montana, and Thymbra capitata, in different environments of Apulia (Italy). C. suaveolens and S. fruticosa subsp. thomasii are rare species of conservation interest, while S. montana subsp. montana and T. capitata, have a wide distribution and are used in traditional medicine or as spices. Results showed that the ecological context (phytosociological and ecological features) may influence the composition of EOs of the studied species. High differences in the compound composition have been found in S. montana subsp. montana, whereas minor effects were observed in C. suaveolens, S. fruticosa subsp. thomasii, and T. capitata accessions. The understanding of such aspects is necessary for providing optimal conditions to produce EOs rich in compounds known for their biological activities. The results are of great interest also for EOs producers and at the same time to improve our knowledge and valorize wild officinal plants.

Essential Oil Composition and Micromorphological Traits of Satureja montana L., S. subspicata Bartel ex Vis., and S. kitaibelii Wierzb. Ex Heuff. Plant Organs

The essential oil (EO) composition of Satureja plants is highly variable. Recent studies suggest that there is an even difference in the EO composition from different plant organs within the same plant. This study aims to examine the chemical profile of EOs and the micromorphological characteristics of different organs of three Satureja species. The relationship between the number of glandular trichomes and EOs profile and relative yield is also investigated. Individuals from five populations were visualized using a scanning electron microscope, while EOs of leaves, calyces, corollas, and whole aerial parts were isolated using simultaneous distillation and extraction and analyzed using gas chromatography/mass spectrometry. Three types of glandular trichomes were detected. Peltate trichomes were present on all plant organs of studied species, while two types of capitate trichomes show different organ and species preferences. The EOs profiles differed across the plant parts, but showed a species specific composition. Univariate and multivariate statistics were used to show a correlation between the peltate trichomes and EO yield, and chemophenetic significance of EO profiles.

A natural post-emergence herbicide based on essential oil encapsulation by cross-linked biopolymers: characterization and herbicidal activity

This work describes efforts to encapsulate savory (Satureja hortensis L.) essential oil (EO) with different natural polymers (i.e., Arabic gum/gelatin (AGG), apple pectin (AP), gelatin (G)) and, as a separate set of experiments, with bio cross-linkers (i.e., citric acid and transglutaminase enzyme). The phytotoxic activity of encapsulated savory EO on tomato (Lycopersicon esculentum Mill.) and amaranth weed (Amaranthus retroflexus L.) was investigated. The micro-capsules were evaluated in terms of size, polydispersity, stability, encapsulation efficiency, morphology, and release properties. The Korsmeyer-Peppas model operated when EO was being released from the micro-capsules. Carvacrol (52.5%) and γ-terpinene (30.2%) comprised the main constituents of the savory EO. Based on the results, encapsulating the EO with cross-linked biopolymers increased the stability and herbicidal activity of EO, as compared to simple EO emulsions. Maximum toxicity injuries (MTI) were caused by encapsulations of apple pectin, cross-linked with APe enzyme (15 ml/L) on both plant species. MTI were observed 2 days after using the micro-encapsulated herbicides (MCHs). However, the injury caused by MCHs on tomato was not significant. The lowest values of fresh weight (2.80 g), chlorophyll a (0.194 mg/g Fw), and total chlorophyll content (0.219 mg/g Fw) of amaranth occurred in response to APe (15 ml/L). Moreover, using AP(e) (10 ml/L) caused the lowest values of starch (0.444 mg/g Fw) and flavonoid contents (4.18 mg Cat/g Fw) in amaranth which measured as 59% and 90% reductions, respectively, in comparison with the control. The highest values of MDA (0.0109 nmol/g Fw) and H₂O₂ (0.0432 μmol/g Fw) were observed in amaranth plants treated with AP(e) (10 ml/L). In summary, cross-linked apple pectin can perform well in slow release delivery systems of agrochemicals. It can be recommended for use in the production of commercial, EO-based natural herbicides.

Phytochemical Evaluation of Tinctures and Essential Oil Obtained from Satureja montana Herb

Winter Savory (Satureja montana L.) has been used in traditional medicine and as a spice or natural food preservative in the Mediterranean region for centuries. In this paper, some technological and analytical aspects of the S. montana tinctures development and an evaluation of the essential oil composition are provided. The total phenolic and flavonoid contents and phenolic compounds profile analyzed spectrophotometrically and by high-performance thin-layer chromatography (HPTLC), respectively, were evaluated in the developed tinctures. The results showed that the tinctures prepared from the S. montana herb by maceration or remaceration are rich in polyphenols, and there is an influence of the technological factors (particle size and extraction mode) on the total phenolic and flavonoid contents. Caffeic, rosmarinic, and chlorogenic acids, (–)-catechin and rutin were identified in the tinctures using the HPTLC method. p-Thymol (81.79%) revealed by gas chromatography-mass spectrometry (GC-MS) was the predominant compound of the essential oil of this plant. Thus, the high contents of polyphenols and flavonoids in the developed tinctures and p-thymol among the volatile components of the S. montana essential oil could indicate the promising antioxidant and antimicrobial properties of these herbal preparations. The obtained results are a ground for the organization of the manufacture of the S. montana tincture and essential oil with the purpose of performing preclinical studies.

Chemical Composition, Antibacterial and Radical Scavenging Activity of Essential Oils from Satureja macrantha C.A.Mey. at Different Growth Stages

Essential oils (EOs) from medicinal and aromatic plants are interesting products to be used as natural food preservatives. The EOs from the genus Satureja are reported to inhibit foodborne pathogens being worthy of use as food preservatives. Satureja macrantha is found in Western and Northwest Iran and commonly used as a food flavoring agent and for the treatment of urinary diseases. The objective of the present study was to identify the chemical composition of S. macrantha EOs at different growth stages (vegetative, flowering and fruiting stages) and to evaluate their biological activities. Chemical compositions were analyzed using GC-FID and GC-MS. The antibacterial activity was evaluated using the broth microdilution method against the foodborne pathogenic bacteria Staphylococcus aureus (ATCC23922), Enterococcus faecalis (ATCC29212) (Gram-positive), Enterobacter aerogenes (ATCC13046) and Escherichia coli. The antioxidant activity was estimated using the DPPH, ABTS and reducing power assays. The yields of S. macrantha EOs were in the range of 1.4–1.8%, thus scalable for the manufacture of food preservatives on an industrial level. The main compounds of EOs were carvacrol (42.7–48.2%), thymol (0.2–16.5%), p-cymene (10.1–14.7%) and γ-terpinene (7.9–9.1%) in all phenological stages examined. The strongest antibacterial activity (MICs = 5–20 µg/mL) of the EOs was recorded in samples obtained during the flowering stage where carvacrol (42.7%) and thymol (16.5) were present both at high percentages. On the other hand, the antioxidant activity was found to be slightly higher in the other stages. As the EO obtained at flowering showed the best inhibitory properties against foodborne pathogenic bacteria, it is suggested that plants at this stage can be selected as main sources of food preservative agents.

Efficacy of Two Monoterpenoids, Carvacrol and Thymol, and Their Combinations against Eggs and Larvae of the West Nile Vector Culex pipiens

Background: Insect vector control is facing the challenges of resistance development and environmental hazards caused by synthetic pesticides. This has led to a considerable market opportunity for botanical insecticides. In this scenario, our study investigated the potential of selected bioactive monoterpenoids, carvacrol and thymol, as safe and effective tools to control the West Nile vector Culex pipiens. Furthermore, the combined effect of thymol-carvacrol mixtures and their possible interactions were assessed. Methods: For determining larvicidal and ovicidal 50% lethal concentration (LC₅₀), each monoterpenoid was tested at different concentrations (5–500 mg/L). Then, the fixed ratio method was used for evaluating their combinational efficacy. Results: Carvacrol was more toxic against larvae of Cx. pipiens, with a LC₅₀ value of 14 mg/L, whereas thymol exhibited a LC₅₀ value of 49 mg/L. Comparable trends of efficacy were observed when toxicity on Cx. pipiens eggs was investigated, with LC₅₀ values of 7 and 13 mg/L for carvacrol and thymol, respectively. In combinational toxicity assays, the mixture thymol-carvacrol at 1:4 ratio achieved a synergistic effect against larvae of Cx. pipiens, whereas an additive effect was observed on eggs. Other ratios showed antagonistic effects. Conclusions: Overall, our findings pointed out that the 1:4 ratio of thymol-carvacrol blend can enhance the insecticidal efficacy on Cx. pipiens young instars and can be considered further as active ingredient for developing botanical insecticides to be used in mosquito control operations.