Satureja montana L. and Origanum majorana L. Decoctions: Antimicrobial Activity, Mode of Action and Phenolic Characterization

Effect of Satureja montana Essential Oil on Model Lipid Membranes

Satureja montana essential oil is a natural substance able to inhibit the growth of several pathogens. This antimicrobial effect is often attributed to its ability to penetrate cellular structures and disrupt them. Although these properties are recognized as playing a key role in the mechanism of action of this substance, many unresolved issues still exist, and fundamental studies focused on such aspects are scarce. In this framework, we investigated the interaction of SEO with lipid monolayers, which represent simplified models of cell membranes, using the Langmuir monolayer technique, complemented by fluorescence anisotropy and differential scanning calorimetry on lipid bilayers. By focusing on packing conditions that approximate those of biological membranes and using lipids with different polar heads and structures, such as the ones occurring in bacterial membranes, we aim to clarify the effect of this essential oil on the lipid membrane. Our results show that Satureja montana essential oil consistently manages to insert into the membrane and interfere with the lipid-lipid interactions, thereby altering the lipid packing and significantly increasing the membrane fluidity, depending on the oil concentration and the nature of the lipid.

Identification of compounds from Origanum compactum and Origanum elongatum using HPLC/UV-ESI-MS and comparative analysis of their antioxidant, antimicrobial, anticoagulant, and antidiabetic properties

The aim was to assess the phytochemical composition, phenolic component levels, and biological properties of the flowering tops of Origanum compactum and Origanum elongatum. The study employed phytochemical assays, spectrophotometric techniques for quantitative analysis of polyphenols, flavonoids, and tannins, and compound identification using HPLC/UV-ESI-MS. The antimicrobial, antioxidant, anticoagulant, and antidiabetic properties were examined both in vitro and in vivo. The results showed that the O. compactum extract had significantly high levels of total polyphenols, measuring 47.368 mg gallic acid equivalents per gram, and flavonoids, measuring 14.839 mg quercetin equivalents per gram. The phytochemical examination of O. compactum revealed that lithospermic acid accounted for 36.82 % of the chemicals detected, followed by salvianolic acid C at 12.57 % and ros-marinic acid at 6.01 %. The main constituents of O. elongatum are salvianolic acid C (14.46 %), luteolin-3-O-glucuronide (13.51 %), salvianolic acid B (12.24 %), rosmarinic acid (7.83 %), and rutin (6.18 %). The results demonstrated different levels of effectiveness against the investigated microorganisms, with the extract from O. compactum exhibiting better activity, particularly against Gram-negative bacteria, certain yeasts, and the fungus Aspergillus niger. The aqueous extracts of both Origanum species demonstrate significant antioxidant activity. O. compactum has a higher total antioxidant capacity (IC50 of 35.083 μg/mL) compared to O. elongatum (IC50 of 77.080 μg/mL). However, O. elongatum has a higher reducing power (35.697 μg/mL) compared to O. compactum (42.563 μg/mL). In vivo evaluations revealed that the aqueous extracts of O. compactum and O. elongatum possess significant antihyperglycemic and anticoagulant properties. The extracts demonstrated a marked reduction in blood glucose levels during the oral glucose tolerance test (OGTT) in Wistar rats and effectively prolonged both prothrombin time (PT) and activated partial thromboplastin time (aPTT), highlighting their ability to inhibit coagulation pathways. Moreover, their comparable efficacy to standard antihyperglycemic medications and absence of severe toxicity, even at high doses, underscore their therapeutic potential for safe and effective treatment applications. Between the two species, O. compactum exhibited superior efficacy in key biological activities such as antioxidant, antimicrobial, and anticoagulant properties, making it a strong candidate for therapeutic applications. This study underscores the value of Origanum species as a rich source of bioactive compounds, offering significant potential in pharmaceuticals, nutraceuticals, and agri-food industries. The findings pave the way for further exploration of their diverse applications.

Chemical profile, in vitro pharmacological activity and Satureja cuneifolia Ten. evaluation of essential oil based on distillation time

The medicinal plant Satureja cuneifolia Ten. was widely utilized as spice, tea and traditional medicine. The objective of the current study was to examine the chemical composition and in vitro biological activities (LOX, MMP-1, and MMP-12 enzyme inhibition activity and cytotoxicity on A549 cell line) of Satureja cuneifolia extracts and essential oils. The essential oils of the flowering aerial parts were hydro-distilled at four different distillation times (5, 30, 60, and 180 min) using the Clevenger apparatus. The total essential oil and four fragments were compared in terms of the major component, yield, and distillation time. Volatile compounds of the infusion were extracted by using HS-SPME. Ethanolic extract had the strongest inhibition activity on the LOX enzyme (84.50%), while the essential oils exhibited more cytotoxic activity on the A549 cell line than the extracts. The oils and the infusion were analyzed using GC-MS and the primary chemicals identified by LC-MS/MS.

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.

Chlorogenic Acid Inhibits Rahnella aquatilis KM25 Growth and Proteolytic Activity in Fish-Based Products

This work verified the antiproliferative and antiproteolytic activities of chlorogenic acid against Rahnella aquatilis KM25, a spoilage organism of raw salmon stored at 4 °C. Chlorogenic acid limited the growth of R. aqatilis KM25 in vitro at a concentration of 2.0 mg/mL. The dead (46%), viable (25%), and injured (20%) cell subpopulations were identified by flow cytometry following treatment of R. aquatilis KM25 with the examined agent. The exposure of R. aquatilis KM25 to chlorogenic acid altered its morphology. Changes in cell dimensions, mostly in length parameters from 0.778 µm to 1.09 µm, were found. The length of untreated cells ranged from 0.958 µm to 1.53 µm. The RT-qPCR experiments revealed changes in the expression of genes responsible for the proliferation and proteolytic activity of cells. Chlorogenic acid caused a significant reduction in the mRNA levels of the ftsZ, ftsA, ftsN, tolB, and M4 genes (-2.5, -1.5, -2.0, -1.5, and -1.5, respectively). In situ experiments confirmed the potential of chlorogenic acid to limit bacterial growth. A similar effect was noted in samples treated with benzoic acid, where the growth inhibition of R. aquatilis KM25 was 85-95%. Reduction of microbial R. aquatilis KM25 proliferation significantly limited total volatile base nitrogen (TVB-N) and trimethylamine (TMA-N) formation during storage, extending the shelf life of model products. The TVB-N and TMA-N parameters did not exceed the upper levels of the maximum permissible limit of acceptability. In this work, the TVB-N and TMA-N parameters were 10-25 mg/100 g and 2.5-20.5 mg/100 g, respectively; for samples with benzoic acid-supplemented marinades, the parameters TVB-N and TMA-N were 7.5-25.0 mg/100 g and 2.0-20.0 mg/100 g, respectively. Based on the results of this work, it can be concluded that chlorogenic acid can increase the safety, shelf life, and quality of fishery products.

Effect of Thymbra capitata (L.) Cav. on Inflammation, Senescence and Cell Migration

Aromatic plants are reported to display pharmacological properties, including anti-aging. This work aims to disclose the anti-aging effect of the essential oil (EO) of Thymbra capitata (L.) Cav., an aromatic and medicinal plant widely used as a spice, as well as of the hydrodistillation residual water (HRW), a discarded by-product of EO hydrodistillation. The phytochemical characterization of EO and HRW was assessed by GC-MS and HPLC-PDA-ESI-MSⁿ, respectively. The DPPH, ABTS, and FRAP assays were used to disclose the antioxidant properties. The anti-inflammatory potential was evaluated using lipopolysaccharide-stimulated macrophages by assessing NO production, iNOS, and pro-IL-1β protein levels. Cell migration was evaluated using the scratch wound assay, and the etoposide-induced senescence was used to assess the modulation of senescence. The EO is mainly characterized by carvacrol, while the HRW is predominantly characterized by rosmarinic acid. The HRW exerts a stronger antioxidant effect in the DPPH and FRAP assays, whereas the EO was the most active sample in the ABTS assay. Both extracts reduce NO, iNOS, and pro-IL-1β. The EO has no effect on cell migration and presents anti-senescence effects. In opposition, HRW reduces cell migration and induces cellular senescence. Overall, our study highlights interesting pharmacological properties for both extracts, EO being of interest as an anti-aging ingredient and HRW relevant in cancer therapy.

Gluten-Free Bread Enriched with Artichoke Leaf Extract In Vitro Exerted Antioxidant and Anti-Inflammatory Properties

Due to its high nutritional value and broad beneficial effects, the artichoke plant (Cynara cardunculus L.) is an excellent healthy food candidate. Additionally, the artichoke by-products are usually discarded even though they still contain a huge concentration of dietary fibers, phenolic acids, and other micronutrients. The present work aimed to characterize a laboratory-made gluten-free bread (B) using rice flour supplemented with a powdered extract from artichoke leaves (AEs). The AE, accounting for the 5% of titratable chlorogenic acid, was added to the experimental gluten-free bread. Accounting for different combinations, four different bread batches were prepared. To evaluate the differences, a gluten-free type-II sourdough (tII-SD) was added in two doughs (SB and SB-AE), while the related controls (YB and YB-AE) did not contain the tII-SD. Profiling the digested bread samples, SB showed the lowest glycemic index, while SB-AE showed the highest antioxidant properties. The digested samples were also fermented in fecal batches containing viable cells from fecal microbiota samples obtained from healthy donors. Based on plate counts, no clear tendencies emerged concerning the analyzed microbial patterns; by contrast, when profiling volatile organic compounds, significant differences were observed in SB-AE, exhibiting the highest scores of hydrocinnamic and cyclohexanecarboxylic acids. The fecal fermented supernatants were recovered and assayed for healthy properties on human keratinocyte cell lines against oxidative stress and for effectiveness in modulating the expression of proinflammatory cytokines in Caco-2 cells. While the first assay emphasized the contribution of AE to protect against stressor agents, the latter enlightened how the combination of SB with AE decreased the cellular TNF-α and IL1-β expression. In conclusion, this preliminary study suggests that the combination of AE with sourdough biotechnology could be a promising tool to increase the nutritional and healthy features of gluten-free bread.

Bioactivity and phenolics profile of aqueous and ethyl acetate extracts of Satureja kitaibelii Wierzb. ex Heuff. obtained by ultrasound-assisted extraction

The aim of the study was to investigate the biological activity and chemical composition of Satureja kitaibelii Wierzb. ex Heuff. LC-PDA/MS analyses for the aqueous extracts (A1-stem, leaves and flowers, A2-leaves and flowers) and ethyl-acetate extracts (E1-stem, leaves and flowers, E2-leaves and flowers) obtained by ultrasound-assisted extraction enabled the identification of thirty-four compounds. Quantitative analysis revealed that the aqueous extract obtained from leaves and flowers was the richest in total phenolic acids (65.36 mg/g) and flavonoids (21.17 mg/g). The total polyphenol content was the highest in the aqueous extract obtained from leaves and flowers (274 ± 2.4 mg Gallic Acid equivalents/g). The best antioxidant activity was observed for the same extract using the DPPH (SC50 20 ± 10 µg/mL), ABTS (2.834 ± 0.02 mg Ascorbic Acid/g), FRAP (1.922 ± 0.03 mmol Fe²⁺/mg), and total reducing power tests (16.4 ± 1.0 mg Ascorbic Acid/g). Both ethyl acetate extracts were the most active against strains of Bacillus cereus and Micrococcus flavus (MIC 1.70-1.99 mg/mL and 1.99-3.41 mg/mL, respectively). They were more efficient against Aspergillus ochraceus (MFC 0.86 mg/mL) and towards HeLa cell lines. All the obtained results implied the good potential of the investigated extracts to be used as effective preservatives and functional ingredients in food products and dietary supplements.

An ethnobotanical study on medicinal plants of Shexian Dryland Stone Terraced System in northern China

BACKGROUND

Shexian Dryland Stone Terraced System (SDSTS) in the Taihang Mountains was formally recognized as Globally Important Agricultural Heritage Systems (GIAHS) by Food and Agriculture Organization on May 20, 2022. People there have been relying on the terraced fields for centuries, using various plants, including medicinal plants. However, little information was reported about the flora in SDSTS, nor medicinal plants. Thus, the present study aims to identify and document medicinal plants traditionally used by the local people living around the SDSTS and associated ethnobotanical knowledge.

METHODS

We conducted investigations in Shexian County, Hebei Province, North China, where SDSTS is distributed. Then, Wangjinzhuang, a community located in the core zone of SDSTS, was chosen as the case site. We selected the informants through purposive and snowball sampling. The data were collected through semi-structured interviews, participant observation, and key informant interviews. The medicinal plants traditionally used by the local people were documented and analyzed. We examined and confirmed the botanical identification based on voucher specimens and by cross-checking the descriptions with the series of books, scientific papers on medicinal plants, and the plant databases.

RESULTS

The local people have rich traditional knowledge to collect and use medicinal plants in SDSTS. Records of 123 medicinal plant species belonging to 51 families were obtained from SDSTS. Asteraceae was represented by 16 species, followed by Fabaceae, Lamiaceae and Ranunculaceae. (They all have 8 species.) The majority of the reported plant species were commonly processed into decoctions. And 180 diseases affecting humans were reported to be treated with traditional medicinal plants from SDSTS.

CONCLUSION

It is the first ethnobotanical study on medicinal plants in China-Nationally Important Agricultural Heritage Systems, and in globally important agricultural heritage systems as well. Medicinal plants are crucial for people living in Shexian County. It is necessary to recognize and respect traditional knowledge peculiar to the mountainous region of northern China, especially for those involved in the human-nature interaction and the role of knowledge in agrobiodiversity conservation and rural development that local residents have persisted for centuries.

Combination Strategies of Different Antimicrobials: An Efficient and Alternative Tool for Pathogen Inactivation

Despite the discovery and development of an array of antimicrobial agents, multidrug resistance poses a major threat to public health and progressively increases mortality. Recently, several studies have focused on developing promising solutions to overcome these problems. This has led to the development of effective alternative methods of controlling antibiotic-resistant pathogens. The use of antimicrobial agents in combination can produce synergistic effects if each drug invades a different target or signaling pathway with a different mechanism of action. Therefore, drug combinations can achieve a higher probability and selectivity of therapeutic responses than single drugs. In this systematic review, we discuss the combined effects of different antimicrobial agents, such as plant extracts, essential oils, and nanomaterials. Furthermore, we review their synergistic interactions and antimicrobial activities with the mechanism of action, toxicity, and future directions of different antimicrobial agents in combination. Upon combination at an optimum synergistic ratio, two or more drugs can have a significantly enhanced therapeutic effect at lower concentrations. Hence, using drug combinations could be a new, simple, and effective alternative to solve the problem of antibiotic resistance and reduce susceptibility.

Spicy and Aromatic Plants for Meat and Meat Analogues Applications

Aromatic and spicy plants are an important factor that contributes not only to improving the taste of meat, meat products, and meat analogues, but also to increasing the nutritional value of the products to which they are added. The aim of this paper is to present the latest information on the bioactive antioxidant and antimicrobial properties of the most commonly used herbs and spices (parsley, dill, basil, oregano, sage, coriander, rosemary, marjoram, tarragon, bay, thyme, and mint) used in the meat and meat analogues industry, or proposed to be used for meat analogues.

Natural Polyphenols for the Preservation of Meat and Dairy Products

Food spoilage makes foods undesirable and unacceptable for human use. The preservation of food is essential for human survival, and different techniques were initially used to limit the growth of spoiling microbes, e.g., drying, heating, salting, or fermentation. Water activity, temperature, redox potential, preservatives, and competitive microorganisms are the most important approaches used in the preservation of food products. Preservative agents are generally classified into antimicrobial, antioxidant, and anti-browning agents. On the other hand, artificial preservatives (sorbate, sulfite, or nitrite) may cause serious health hazards such as hypersensitivity, asthma, neurological damage, hyperactivity, and cancer. Thus, consumers prefer natural food preservatives to synthetic ones, as they are considered safer. Polyphenols have potential uses as biopreservatives in the food industry, because their antimicrobial and antioxidant activities can increase the storage life of food products. The antioxidant capacity of polyphenols is mainly due to the inhibition of free radical formation. Moreover, the antimicrobial activity of plants and herbs is mainly attributed to the presence of phenolic compounds. Thus, incorporation of botanical extracts rich in polyphenols in perishable foods can be considered since no pure polyphenolic compounds are authorized as food preservatives. However, individual polyphenols can be screened in this regard. In conclusion, this review highlights the use of phenolic compounds or botanical extracts rich in polyphenols as preservative agents with special reference to meat and dairy products.

Phenolic-Rich Plant Extracts With Antimicrobial Activity: An Alternative to Food Preservatives and Biocides?

In recent years, the search for natural plant-based antimicrobial compounds as alternatives to some synthetic food preservatives or biocides has been stimulated by sanitary, environmental, regulatory, and marketing concerns. In this context, besides their established antioxidant activity, the antimicrobial activity of many plant phenolics deserved increased attention. Indeed, industries processing agricultural plants generate considerable quantities of phenolic-rich products and by-products, which could be valuable natural sources of natural antimicrobial molecules. Plant extracts containing volatile (e.g., essential oils) and non-volatile antimicrobial molecules can be distinguished. Plant essential oils are outside the scope of this review. This review will thus provide an overview of current knowledge regarding the promises and the limits of phenolic-rich plant extracts for food preservation and biofilm control on food-contacting surfaces. After a presentation of the major groups of antimicrobial plant phenolics, of their antimicrobial activity spectrum, and of the diversity of their mechanisms of action, their most promising sources will be reviewed. Since antimicrobial activity reduction often observed when comparing in vitro and in situ activities of plant phenolics has often been reported as a limit for their application, the effects of the composition and the microstructure of the matrices in which unwanted microorganisms are present (e.g., food and/or microbial biofilms) on their activity will be discussed. Then, the different strategies of delivery of antimicrobial phenolics to promote their activity in such matrices, such as their encapsulation or their association with edible coatings or food packaging materials are presented. The possibilities offered by encapsulation or association with polymers of packaging materials or coatings to increase the stability and ease of use of plant phenolics before their application, as well as to get systems for their controlled release are presented and discussed. Finally, the necessity to consider phenolic-rich antimicrobial plant extracts in combination with other factors consistently with hurdle technology principles will be discussed. For instance, several authors recently suggested that natural phenolic-rich extracts could not only extend the shelf-life of foods by controlling bacterial contamination, but could also coexist with probiotic lactic acid bacteria in food systems to provide enhanced health benefits to human.

Comparative Assessment of Medicinal Plant Utilization among Balti and Shina Communities in the Periphery of Deosai National Park, Pakistan

Simple Summary

Traditional ecological knowledge is a key contributor to environmental sustainability; therefore, it is essential to identify and preserve this biocultural heritage. We documented traditional uses of plant species among the two marginalized communities, namely Baltis and Shinas, living in Deosai National Park, western Himalayas, Pakistan, using random and purposive sampling techniques targeting middle- and old-aged informants. In total, 47 medicinal plant species were recorded, which were cited by both Baltis and Shinas (42 and 38 plant species, respectively) to treat various diseases. Considerable homo- and heterogeneities were noted in vernacular names, plant part(s) used, drug formulation, and administration. Ribes alpestre, Aconitum violaceum, Delphinium brunonianum, Thymus linearis, and Swertia petiolata were the highly utilized species. In addition, medicinal uses of Allardia tomentosa, A. tridactylites, Jurinea dolomiaea, and Gallium boreale were reported for the first time from this region. Both Balti and Shina communities retain substantial biocultural and ethnological diversity, which has been reflected in the present survey.

Abstract

Traditional ecological knowledge, linguistic, and sociocultural perspectives are key contributors to environmental sustainability. Therefore, it is essential to identify and preserve this biocultural heritage, especially that of indigenous communities and minorities. We conducted an ethnobotanical survey to document the plant species used by the Balti and Shina communities living in the buffer zone of Deosai National Park (DNP), western Himalayas, Pakistan. A combination of random and purposive sampling techniques was adapted, targeting middle- and old-aged informants. A total of 46 semi-structured interviews were conducted and the gathered data were evaluated using relative frequency of citation (RFC) and through comparison with the ethnomedicinal literature. In total, 47 medicinal plant species belonging to 42 genera and 23 families were recorded. Baltis and Shinas cited 42 and 38 plant species, respectively, that were used to treat various diseases. About 60% of species were common among both communities, but 27.7% and 12.8% were exclusive to Baltis and Shinas, respectively. Considerable heterogeneity was noted in vernacular names, plant part(s) used, preparation, and administration. Ribes alpestre, Aconitum violaceum, Delphinium brunonianum, Thymus linearis, and Swertia petiolata were highly utilized species having RFCs > 50. In addition, 46% of medicinal uses, specifically that of Allardia tomentosa, A. tridactylites, Jurinea dolomiaea, and Gallium boreale, were reported for the first time from the region. Cross-cultural analysis revealed sociocultural gaps between both groups. Relatively, Baltis retained more ethnomedicinal knowledge and their traditional medicinal system is more closely associated with traditional Tibetan medicine. Generally, Balti and Shina communities retain substantial biocultural and ethnological diversity, which has been reflected in the present study. Our findings underline the importance and need for sustainable utilization of natural resources, specifically the plant species of this region. However, an in-depth ethnobotanical investigation may underpin the holistic comparative medical ethnobotany of the entire region.

Antioxidant, Antihypertensive and Antimicrobial Properties of Phenolic Compounds Obtained from Native Plants by Different Extraction Methods

This study aims to evaluate the efficacy of two methods (agitation and ultra-sound) for extracting phenolic compounds from 15 native plants. Plant species collected in the Dehesa of Extremadura were used. The antioxidant, antihypertensive and antimicrobial activity of the phenolic extracts was investigated. Significantly different results were obtained when comparing the two extraction methods, with the highest concentrations of phenolic compounds found for ultrasound extraction. In addition, the extracts obtained for Cistus albidus, Cistus salviifolius, Rubus ulmifolius and Quercus ilex showed the highest concentrations of phenolic compounds. The antioxidant activity was higher in the extracts of Cistus and Q. ilex obtained by ultrasound, as was the antihypertensive activity. Antimicrobial activity was also higher in the extracts obtained by ultrasound from C. salviifolius and Q. ilex plants against bacteria and from Cistus ladanifer against yeasts. Therefore, it can be concluded that, with the ultrasound extraction of phenolic compounds from C. ladanifer, C. albidus and Q. ilex plants, it is possible to obtain extracts with important functional properties, so they could be studied for their use in food with the aim of obtaining healthy and safe products, favouring the sustainability of the environment of the Dehesa Extremeña.