Rapid, cost-effective and organic solvent-free production of biologically active essential oil from Mediterranean wild Origanum syriacum

Exploring the phytoconstituents, antimicrobial potency, and cytotoxic effects of essential oil from Origanum punonense from Palestine

BACKGROUND

Origanum punonense Danin is one of the old traditional medicinal plants Bedouins utilize in the Dead Sea region to treat a variety of illnesses, those caused by infections. The current study aimed to identify the phytochemical components of O. punonense essential oil (EO) and determine its antiproliferative and antimicrobial effects.

METHODS

Gas chromatography and mass spectrometry were employed to detect the phytochemical constituents of O. punonense EO. Broth microdilution assay was utilized to determine the antimicrobial effects against various microbial species, including those causing diabetic foot infections.

RESULTS

This study revealed that O. punonense EO contains 44 phytochemical compounds, of which 41 compounds were detectable and amounted to 99.78% of the total oil. The main chemical components of the oil were carvacrol (57.4%), p-cymene (6.66%), carvone (5.35%), pinene (4.9%), and terpinene (2.96%). The antiproliferative activity of different concentrations of O. punonense EO was noted in all of the investigated cell lines, with the best activity at the concentration of 500 µg/mL. The greatest antibacterial activity was against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Proteus vulgaris, with MIC values of 1.56 µL/mL. In addition, and the O. punonense EO showed strong antifungal activity against Candida albicans with a MIC value of 0.8 µL/mL. In addition, the O. punonense EO showed potent antibacterial activity against all MRSA samples obtained from the diabetic foot with a MIC value of 3.13 µL/mL. The O. punonense EO demonstrated potent activity against Carbapenem-resistant Enterobacterales, Citrobacter freundii, and K. pneumoniae, with MICs value of 6.25 µL/mL.

CONCLUSION

The potent antiproliferative and broad antimicrobial activity of O. punonense EO makes it an effective strategy for treating infections, especially in immunocompromised patients with chronic comorbidities such as cancer and diabetes mellitus.

Current State of Knowledge Regarding WHO High Priority Pathogens-Resistance Mechanisms and Proposed Solutions through Candidates Such as Essential Oils: A Systematic Review

Combating antimicrobial resistance (AMR) is among the 10 global health issues identified by the World Health Organization (WHO) in 2021. While AMR is a naturally occurring process, the inappropriate use of antibiotics in different settings and legislative gaps has led to its rapid progression. As a result, AMR has grown into a serious global menace that impacts not only humans but also animals and, ultimately, the entire environment. Thus, effective prophylactic measures, as well as more potent and non-toxic antimicrobial agents, are pressingly needed. The antimicrobial activity of essential oils (EOs) is supported by consistent research in the field. Although EOs have been used for centuries, they are newcomers when it comes to managing infections in clinical settings; it is mainly because methodological settings are largely non-overlapping and there are insufficient data regarding EOs' in vivo activity and toxicity. This review considers the concept of AMR and its main determinants, the modality by which the issue has been globally addressed and the potential of EOs as alternative or auxiliary therapy. The focus is shifted towards the pathogenesis, mechanism of resistance and activity of several EOs against the six high priority pathogens listed by WHO in 2017, for which new therapeutic solutions are pressingly required.

Origanum syriacum Phytochemistry and Pharmacological Properties: A Comprehensive Review

Herbal medicine has been gaining special interest as an alternative choice of treatment for several diseases, being generally accessible, cost-effective and safe, with fewer side-effects compared to chemically synthesized medicines. Over 25% of drugs worldwide are derived from plants, and surveys have shown that, when available, herbal medicine is the preferred choice of treatment. Origanum syriacum (Lamiaceae) is a widely used medicinal plant in the Middle East, both as a home and a folk remedy, and in the food and beverage industry. Origanum syriacum contains numerous phytochemical compounds, including flavonoids, phenols, essential oils, and many others. Because of its bioactive compounds, O. syriacum possesses antioxidant, antimicrobial, and antiparasitic capacities. In addition, it can be beneficial in the treatment of various diseases such as cancer, neurodegenerative disorders, and peptic ulcers. In this review, the chemical compositions of different types of extracts and essential oils from this herb will first be specified. Then, the pharmacological uses of these extracts and essential oils in various contexts and diseases will be discussed, putting emphasis on their efficacy and safety. Finally, the cellular and molecular mechanisms of O. syriacum phytochemicals in disease treatment will be described as a basis for further investigation into the plant's pharmacological role.

Comparison between Quality Traits of Solar-Dried and Freeze-Dried Origanum syriacum L. (Za'atar)

There is growing interest in Origanum syriacum due to attractive culinary applications and functional properties. Solar drying is the most common conventional method for drying Origanum syriacum L. (Za’atar) in Mediterranean region. This study aimed to evaluate the quality traits of solar dried za’atar in comparison to freeze dried za’atar. Proximate composition (moisture, protein, fat, fiber, carbohydrates, and ash), color index (L*a*b*), macro and microstructure, sensory, and microbiological characteristics were evaluated. Solar dried za’atar exhibited significantly lower fat content (1.10 vs. 1.64%, p < 0.05) than freeze dried za’atar. Solar drying led to severe changes in color values compared to freeze drying. Solar drying exhibited loss in the structural integrity and leave hairs more than freeze drying. Moreover, freeze-dried za’atar exhibited significantly lower total aerobic count (4.92 vs. 5.23, p < 0.05) and yeasts and mold count (4.59 vs. 5.36, p < 0.05) than solar-dried za’atar. Panelists were able significantly to differentiate between solar- and freeze dried za’atar. Freeze-dried za’atar had significantly lower hedonic score of color, odor, taste, and overall acceptance than solar dried za’atar. In conclusion, using freeze drying achieved good improvements in some quality traits for za’atar while solar dried za’atar showed better sensory perception.

Ultrasonic-Assisted Thymol and Carvacrol Extraction from Za’atar Leaves Using Cold-Pressed Sesame Oil

Thymol and carvacrol found in Origanum syriacum “Za’atar” plant leaves have triggered interest among researchers for their natural antimicrobial and antifungal properties. However, their applications in modern pharmaceutical and cosmetic industries as natural preservatives remain challenging. In this research, extraction of thymol and carvacrol from Za’atar leaves has been investigated using the ultrasonic-assisted method and the use of sesame oil as the primary extraction solvent compared with other vegetable oils including sunflower and olive oils. In addition, a high-performance liquid chromatography (HPLC) analytical method was developed by using a C8 column and 0.05% trifluoroacetic acid as a buffering agent. The method was validated for specificity, linearity, repeatability, accuracy, and robustness for the analysis of the content of the two terpenes thymol and carvacrol in different Za’atar extracts. Using the validated analytical method, thymol and carvacrol content results revealed the best vegetable oil for extraction. Results showed that sesame oil had the highest content of thymol and carvacrol, followed by sunflower oil, and the least amount obtained by using olive oil. A consistent extraction result opens an opportunity for application in the pharmaceutical and cosmetic industries. For this reason, the essential extraction key parameters that influence the final content of thymol and carvacrol were evaluated. The highest impact originated from the quality and volume of sesame oil. Cold-pressed sesame oil resulted in a 23% higher content of thymol and decreased amount of carvacrol. It was found that wetting the Za’atar leaves powder with sesame oil was enough for extraction; any additional sesame oil volume dilutes the extracted sample. The second impact was the Za’atar cultivation conditions; less than 10% difference of thymol and carvacrol content was observed within Za’atar of Hebron origin. Finally, the origin of sesame seeds used for sesame oil production had the least impact.

Ultrasonic-Assisted Thymol and Carvacrol Extraction from Za’atar Leaves Using Cold-Pressed Sesame Oil

Thymol and carvacrol found in Origanum syriacum “Za’atar” plant leaves have triggered interest among researchers for their natural antimicrobial and antifungal properties. However, their applications in modern pharmaceutical and cosmetic industries as natural preservatives remain challenging. In this research, extraction of thymol and carvacrol from Za’atar leaves has been investigated using the ultrasonic-assisted method and the use of sesame oil as the primary extraction solvent compared with other vegetable oils including sunflower and olive oils. In addition, a high-performance liquid chromatography (HPLC) analytical method was developed by using a C8 column and 0.05% trifluoroacetic acid as a buffering agent. The method was validated for specificity, linearity, repeatability, accuracy, and robustness for the analysis of the content of the two terpenes thymol and carvacrol in different Za’atar extracts. Using the validated analytical method, thymol and carvacrol content results revealed the best vegetable oil for extraction. Results showed that sesame oil had the highest content of thymol and carvacrol, followed by sunflower oil, and the least amount obtained by using olive oil. A consistent extraction result opens an opportunity for application in the pharmaceutical and cosmetic industries. For this reason, the essential extraction key parameters that influence the final content of thymol and carvacrol were evaluated. The highest impact originated from the quality and volume of sesame oil. Cold-pressed sesame oil resulted in a 23% higher content of thymol and decreased amount of carvacrol. It was found that wetting the Za’atar leaves powder with sesame oil was enough for extraction; any additional sesame oil volume dilutes the extracted sample. The second impact was the Za’atar cultivation conditions; less than 10% difference of thymol and carvacrol content was observed within Za’atar of Hebron origin. Finally, the origin of sesame seeds used for sesame oil production had the least impact.

Prospects for using Origanum Syriacum (L.) as a source of antimicrobial agents

Origanum syriacum (O. syriacum) (L.) belongs to Group B of the genus Origanum from (Lamiaceae), which is rich in essential oils that exhibit antimicrobial efficacy, anti-inflammatory efficacy, antioxidant activity, and antitumor efficacy. These processing activities are because of its richness in carvacrol and Thymol. In this article, we will focus on O. syriacum, discussing the antimicrobial efficacy for its essential oil and extracts, in addition, cast light on mechanism of essential oil antimicrobial action. This study was conducted from March 2019 to February 2021. We have analyzed the results of studies on antimicrobial efficacy of a plant O. syriacum in the PubMed, Google Scholar, Elsevier over the past 15 years using keywords. O. syriacum essential oil and its extracts have an extensive antimicrobial efficacy give it a great importance in pharmaceutical and medical purposes.

A Systematic Review on the Antimicrobial Properties of Mediterranean Wild Edible Plants: We Still Know Too Little about Them, but What We Do Know Makes Persistent Investigation Worthwhile

(1) Introduction: Bacterial resistance to antibiotics is estimated to be the cause of a major number of deaths by 2050 if we do not find strategies to slow down the rise of drug resistance. Reviews on Mediterranean wild edible plants (MWEPs) with antimicrobial properties are scarce in the main databases (PubMed, Scopus, and WoS). Hence, we proceeded to conduct a new review of the studies on MWEPs. (2) Methods: We used ‘wild edible plant’ and ‘antimicrobial’ as keywords. Within this group, exclusion criteria were reviews, studies concerning non-Mediterranean plants or non-edible plants, studies on topics other than plants or containing no description of antimicrobial properties, or off-topic studies. (3) Results: Finally, out of the one hundred and ninety-two studies we had started with, we reviewed thirty-eight (19.8%) studies concerning the antimicrobial properties of seventy-four MWEPs species belonging to twenty-five Families. Fifty-seven (77%) species out of seventy-four proved to be antimicrobial, with a stringent threshold selection. (4) Conclusions: Studies are still very heterogeneous. We still know too little about MWEPs’ properties; however, what we already know strongly recommends carrying on investigation.

Origanum syriacum L. (Za'atar), from Raw to Go: A Review

The interest in za'atar has increased in recent years due to its economic, cultural, and functional importance. The traditional za'atar mix made from dried Origanum syriacum is now a demanded product nationally and internationally. Air-drying at low temperatures can preserve za'atar quality traits better than other techniques such as oven-drying. The Palestinian za'atar market has the potential to develop and increase its value. However, it is facing many challenges. Another valuable product of za'atar is essential oil. Za'atar essential oil quantity and quality are affected by many factors including geographical location, cultivation, harvesting season, soil, extraction method, temperature, and others. These factors interact with za'atar and with each other; therefore, some factors are more effective than others and further research is needed to determine the optimum condition for producing and obtaining za'atar essential oil. Antimicrobial and antioxidant activities are the main functionalities of za'atar essential oil that are behind its medicinal importance. One hundred and twenty-one compounds have been identified in za'atar essential oil. The most common compounds are thymol, γ-terpinene, carvacrol, and α-pinene. The variation in the composition among za'atar essential oil samples results from the different conditions of the studies during za'atar growth as well as essential oil extraction.

Glechoma curviflora Volatile Oil from Palestine: Chemical Composition and Neuroprotective, Antimicrobial, and Cyclooxygenase Inhibitory Activities

The rise of the emergence of microbial resistance of antibiotics, the dangerous side effects of nonsteroidal anti-inflammatory drugs, and noncompetent medications of Alzheimer's, Parkinson's, and other neurodegenerative diseases prompt scientists to search for phytochemicals that could be utilized in the remedy of lethal diseases. Glechoma curviflora (Boiss.) Kuntze (Nepeta curviflora) is a medicinal herb growing in the eastern parts of the Mediterranean Sea Basin and is widely consumed as a tea. The leaves of this plant have been traditionally used for the treatment of various infectious diseases. The current research was designed to identify the chemical composition of Glechoma curviflora (Boiss.) essential oil (EO) and to assess its antibacterial, antifungal, and cyclooxygenase inhibitory activities and the biophysical gating effect on AMPA receptors. Twenty phytochemicals were identified from G. curviflora leaves and flowers EO amounting to almost 100% of the total constituents using GC-MS technique, of which 1,6-dimethylspiro[4.5]decane (27.51%) 1, caryophyllene oxide (20.08%) 2, and β-caryophyllene (18.28%) 3 were the main constituents. The biophysical properties' effect from the plant extract on various AMPA-type receptors expressed in Human Embryonic Kidney (HEK293) cells was assessed by exploiting the whole-cell patch-clamp technique. Microdilution assay was adopted for assessing the antimicrobial property against eight virulent microbial strains whilst the cyclooxygenase inhibition effect was accomplished utilizing COX inhibitory screening colorimetric assay G. curviflora EO displayed potent activity against P. aeruginosa (MIC = 1.25 μg/mL), S. sonnei (MIC = 3.12 μg/mL), and E. coli (MIC = 1.25 μg/mL), compared with ciprofloxacin (positive control) and potent antibacterial activity against S. aureus, MRSA, S. sonnei, E. coli, and P. aeruginosa compared to Ampicillin (2nd positive control). It also showed anti-Candida (MIC = 6.25 μg/mL) and antimold (MIC = 3.125 μg/mL) activities compared with fluconazole (antifungal positive control). Likewise, our results showed an inhibition and biophysical impact of G. curviflora on all AMPARs subunits.

Antihypertensive power of Naringenin is mediated via attenuation of mineralocorticoid receptor (MCR)/ angiotensin converting enzyme (ACE)/ kidney injury molecule (Kim-1) signaling pathway

Hypertension is a condition with chronic elevation of blood pressure and a common preventable risk factor for cardiovascular disease with attendant global morbidity and mortality. The present study investigated the novel antihypertensive and neuroprotective effect of Naringenin on L-N^G-Nitro arginine methyl ester (L-NAME) induced hypertension together with possible molecular mechanism of action. Rats were divided into four groups. Rats in Group A were normotensive. The hypertensive group (Group B) received 40 mg/kg) of L-NAME alone while Groups C and D were concurrently administered Naringenin (50 mg/kg) or Lisinopril (10 mg/Kg) together with L-NAME orally for 3 weeks. Blood pressure parameters, markers of oxidative stress and renal damage were measured. The immunohistochemistry of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme were also determined. Results indicated significant increases in malondialdehyde, advanced oxidation protein products, protein carbonyl contents and decrease in serum nitric oxide bioavailability in hypertensive rats. Furthermore, there were significant increases in serum myeloperoxidase, urinary creatinine, albumin and blood urea nitrogen in hypertensive rats in comparison to hypertensive rats treated with either Naringenin or Lisinopril. Immunohistochemistry reveal significant expressions of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme in hypertensive rats. However, co-treatment with either Naringenin or Lisinopril mitigated both renal and neuronal oxidative stress, normalized blood pressure and lowered the expressions of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme. Collectively, Naringenin offered a novel antihypertensive and neuroprotective effect through down regulation of kidney injury molecule 1, mineralocorticoid receptor and angiotensin converting enzyme.

Composition, Anticholinesterase and Antipedicular Activities of Satureja capitata L. Volatile Oil

The emergence of resistance for antipedicular agents and the need of potent acetylcholinesterase (AChE) therapeutics for the treatment of a neurodegenerative disorder such as Alzheimer disease has led researchers to the exploration of new therapeutic alternatives such as natural volatile oils. Therefore, the current investigation aimed to identify the components of Satureja capitata L. volatile oil (VO), and examine the VO anticholinesterase, and antipedicular activities. The plant phytoconstituents were identified using Gas chromatography mass spectrometry (GC-MS) method, while the anticholinesterase activity was determined against butyryl- and acetyl-cholinesterase using Ellman’s method. In addition, antipedicular activity was established using the diffusion method. The obtained GC-MS results identified 16 compounds in S. capitata VO with the major constituents being carvacrol, γ-terpinene, and p-cymene. Anticholinesterase analysis showed a marked inhibition potential against acetyl- and butyryl-cholinesterase enzymes with half maximal inhibitory concentration (IC50) values of 28.24±0.97 μg/ml and 92.31±1.22 μg/ml, respectively in comparison with the reference compound galantamine, which has IC50 values against the same enzymes of 5.21±0.07 μg/ml and 10.33±0.37 μg/ml, respectively. In addition, the VO, at a concentration of 20%, was effective against head lice, similar to benzyl benzoate, which resulted in 100% mortality. In addition, the VO completely inhibited the emergence of lice nits after 6 and 14 days. On the basis of the obtained results, S. capitata VO is a promising natural alternative to synthetic antipedicular and anticholinesterase drugs, which can be employed in drug development, and may lead to new candidates against head lice and neurodegenerative diseases.

Fingerprinting, Antimicrobial, Antioxidant, Anticancer, Cyclooxygenase and Metabolic Enzymes Inhibitory Characteristic Evaluations of Stachys viticina Boiss. Essential Oil

The present study aimed to identify the chemical constituents and to assess the in-vitro, antimicrobial, anticancer, antioxidant, metabolic enzymes and cyclooxygenase (COX) inhibitory properties of essential oil (EO) of Stachys viticina Boiss. leaves. The S. viticina EO was isolated and identified using microwave-ultrasonic and GC-MS techniques, respectively. Fifty-two compounds were identified, of which endo-borneol was the major component, followed by eucalyptol and epizonarene. The EO was evaluated against a panel of in-vitro bioassays. The EO displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Epidermophyton floccosum, with MIC values of 0.039, 0.078 and 0.78 mg/mL, respectively. The EO exhibited cytotoxicity against HeLa (cervical adenocarcinoma) and Colo-205 (colon) cancer cell lines with percentages of inhibition of 95% and 90%, for EO concentrations of 1.25 and 0.5 mg/mL, respectively. Furthermore, it showed metabolic enzyme (α-amylase, α-glucosidase, and lipase) inhibitory (IC₅₀ = 45.22 ± 1.1, 63.09 ± 0.26, 501.18 ± 0.38 µg/mL, respectively) and antioxidant activity, with an IC₅₀ value of 19.95 ± 2.08 µg/mL. Moreover, the S. viticina EO showed high cyclooxygenase inhibitory activity against COX-1 and COX-2 with IC₅₀ values of 0.25 and 0.5 µg/mL, respectively, similar to those of the positive control (the NSAID etodolac). Outcomes amassed from this investigation illustrate that S. viticina EO represents a rich source of pharmacologically active molecules which can be further validated and explored clinically for its therapeutic potential and for the development and design of new natural therapeutic preparations.