Inhibitory effects of Zataria multiflora essential oil and its main components on nitric oxide and hydrogen peroxide production in glucose-stimulated human monocyte

Thymol as a Potential Neuroprotective Agent: Mechanisms, Efficacy, and Future Prospects

Neurodegenerative diseases pose a growing global health challenge, with limited effective therapeutic options. Mitochondrial dysfunction, oxidative stress, neuroinflammation, apoptosis, and autophagy are common underlying mechanisms in these diseases. Thymol is a phenolic monoterpene compound that has gained attention for its diverse biological properties, including antioxidant, anti-inflammatory, and immunomodulatory activities. Thymol supplementation could provide potential neuroprotection and improve cognitive deficits, depressant-like effects, learning, and memory impairments in rodents. Mechanistic investigations reveal that the neuroprotective effects of thymol involve the improvement of oxidative stress, mitochondrial dysfunction, and inflammatory response. Several signaling pathways, including mitochondrial apoptotic, NF-κB, AKT, Nrf2, and CREB/BDNF pathways are also involved. In this review, the neuroprotective effects of thymol, the potential molecular mechanisms, safety, applications, and current challenges toward development as a neuroprotective agent were summarized and discussed. We hope that this review provides valuable insights for the further development of this promising natural product as a promising neuroprotective agent.

Effects of Lamiaceae family plants and their bioactive ingredients on coronavirus-induced lung inflammation

Coronaviruses (CoVs) are a family of viruses that cause infection in respiratory and intestinal systems. Different types of CoVs, those responsible for the SARS-CoV and the new global pandemic of coronavirus disease 2019 in people, have been found. Some plants were used as food additives: spices and dietary and/or medicinal purposes in folk medicine. We aimed to provide evidence about possible effects of two Lamiaceae family plants on control or treatment of CoVs-induced inflammation. The keywords including coronaviruses, Thymus vulgaris, Zataria multiflora, thymol, carvacrol, antivirus, and anti-inflammatory and antioxidant effects were searched in various databases such as PubMed, Web of Sciences (ISI), and Google Scholar until September 2022. The medicinal herbs and their main ingredients, thymol and carvacrol, showed antiviral properties and reduced inflammatory mediators, including IL-1β; IL-6, and TNF-α, at both gene and protein levels but increased the levels of IFN-γ in the serum as anti-inflammatory cytokine. These medicinal herbs and their constituents also reduce oxidative stress and enhance antioxidant capacity. The results of molecular docking analyses also indicated that polyphenol components such as thymol, carvone, and carvacrol could inhibit the entry of the viruses into the host cells in molecular docking analyses. The antiviral, anti-inflammatory, and antioxidant effects of these plants may be due to actions of their phenolic compounds that modulate immune response and may be useful in the control and treatment of CoV-induced lung disorder.

Anti-oxidative and anti-hyperglycemic properties of Agastache foeniculum essential oil and oily fraction in hyperglycemia-stimulated and lipopolysaccharide-stimulated macrophage cells: In vitro and in silico studies

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperglycemia (HG) and lipopolysaccharide (LPS) often promote superoxide accumulation, which may increase oxidative stress. Reducing superoxide production in hyperglycemia and the inflammatory condition is an emerging way to reduce protein and lipid oxidation and diabetes complication.

AIM OF STUDY

To examine the effect of Agastache foeniculum essential oil (AFEO) and oil fraction (AFoil) on HG- and LPS-stimulated oxidative stress, the pathogenicity of AFEO and AFoil on oxidative stress was assessed.

METHODS

The stimulatory effects of AFEO and AFoil on the activity and expression of NADH oxide (NOX), catalase (CAT), superoxide dismutase (SOD), and the expression of nuclear respiratory factor 2 (NRF2) and nuclear factor-kappa B (NF-kB) in the stimulated macrophage cell line, J774.A1, was studied. The interaction patterns of AFEO and AFoil components with NOX, SOD, CAT, NRF2, and NF-kB proteins were also deduced using molecular docking.

RESULTS

Estragole was the main ingredient in AFEO (97%). Linolenic acid (32.10%), estragole (16.22%), palmitic acid (12.62%), linoleic acid (12.04%), and oleic acid (8.73%) were the major chemical components of the AFoil. NOX activation was stimulated in macrophage cells by HG and LPS. At 20 μg/mL, AFEO and AFoil decreased NOX activity while increased SOD and CAT activities in stimulated macrophages. AFoil with estragole and omega-3 fatty acids was better than AFEO with estragole in anti-hyperglycemic and anti-oxidative activity. According to molecular docking research, estragole, linoleic acid, and linolenic acid bind to different hydrophobic pockets of NOX, SOD, CAT, NFR2, and NF-kB using hydrogen bonds, van der Waals bonds, pi-alkyl, and pi-anion interactions, with different binding energies.

CONCLUSION

AFEO and AFoil showed antioxidant and anti-diabetic activity. The mechanisms in lowering oxidative stress markers depended on down-regulating superoxide-producing enzymes and up-regulating superoxide-removing enzymes at gene and protein levels. The AFoil emulsion can be used to reduce the detrimental impacts of hyperglycemia and oxidative stress.

The effect of Zataria multiflora on respiratory allergic and immunologic disorders, experimental and clinical evidence: A comprehensive review

Zataria multiflora (Z. multiflora) is used in traditional and modern medicine for therapeutic objectives especially in respiratory disorders. Therefore, updated experimental and clinical studies on the effects of Z. multiflora on respiratory, allergic, and immunologic disorders are reviewed. Various electronic search engines including PubMed, Science Direct, Scopus, and Google Scholar were searched using appropriate keywords until the end of November 2021. Books, thesis-hard copies of some articles were also included. The effects of Z. multiflora on respiratory disorders including asthma, chronic obstructive pulmonary disease (COPD), lung infection, and lung cancer were shown. Extracts of Z. multiflora showed the relaxant effect with various mechanisms. The preventive effects of Z. multiflora were also demonstrated by mechanisms such as antioxidant, immunomodulatory, and antiinflammatory properties in the experimental animal models of different respiratory diseases. Carvacrol and thymol are probably responsible for the therapeutic effect of plant among 56 constituents of Z. multiflora. In addition, bronchodilatory and preventive effects of the plant and its constituents on asthma, COPD, lung disorders due to noxious agents and allergic and immunologic disorders were shown in the clinical studies. Therefore Z. multiflora and its constituents may be considered as a preventive and/or relieving therapy in various respiratory diseases.

Accelerative effect of topical Zataria multiflora essential oil against infected wound model by modulating inflammation, angiogenesis, and collagen biosynthesis

CONTEXT

Zataria multiflora Boiss (Lamiaceae) essential oil (ZME) is believed to be a bactericide herbal medicine and might alleviate negative effects of infection.

OBJECTIVE

This study evaluates the effects of an ointment prepared from ZME (ZMEO) on infected wounds.

MATERIALS AND METHODS

A full-thickness excisional skin wound was surgically created in each mouse and inoculated with 5 × 10⁷ suspension containing Pseudomonas aeruginosa and Staphylococcus aureus. The BALB/c mice (n = 72) were divided into four groups: (1) negative control that received base ointment (NCG), (2) positive control that daily received Mupirocin^® (MG), (3) therapeutic ointment containing 2% ZMEO and (4) therapeutic ointment containing 4% ZMEO, for 21 days. Wound contraction, total bacterial count, histopathological parameters, antioxidant activity, qRT-PCR analysis for expression of IL-1β, TNF-α, VEGF, IGF-1, TGF-β, IL-10, and FGF-2 mRNA levels were assessed on days 3, 7, and 14 following the wounding.

RESULTS

Topical administration of ZMEO significantly decreased the total bacterial count and wound area and also expression of IL-1β and TNF-α compared to the control groups (p < 0.05) in all days. This could also increase significantly the expression of TGF-β, IL-10 IGF-1, FGF-2, and VEGF, and also angiogenesis, fibroblasts, fibrocytes, epithelialization ratio, and collagen deposition and improve antioxidant status compared to the control group (p < 0.05).

DISCUSSION AND CONCLUSION

ZMEO accelerated the healing process of infected wounds by shortening the inflammatory factors and increasing proliferative phase. Applying ZMEO only and/or in combination with chemical agents for the treatment of wound healing could be suggested.

p-cymene impairs SARS-CoV-2 and Influenza A (H1N1) viral replication: In silico predicted interaction with SARS-CoV-2 nucleocapsid protein and H1N1 nucleoprotein

Therapeutic regimens for the COVID-19 pandemics remain unmet. In this line, repurposing of existing drugs against known or predicted SARS-CoV-2 protein actions have been advanced, while natural products have also been tested. Here, we propose that p-cymene, a natural monoterpene, can act as a potential novel agent for the treatment of SARS-CoV-2-induced COVID-19 and other RNA-virus-induced diseases (influenza, rabies, Ebola). We show by extensive molecular simulations that SARS-CoV-2 C-terminal structured domain contains a nuclear localization signal (NLS), like SARS-CoV, on which p-cymene binds with low micromolar affinity, impairing nuclear translocation of this protein and inhibiting viral replication, as verified by preliminary in vitro experiments. A similar mechanism may occur in other RNA-viruses (influenza, rabies and Ebola), also verified in vitro for influenza, by interaction of p-cymene with viral nucleoproteins, and structural modification of their NLS site, weakening its interaction with importin A. This common mechanism of action renders therefore p-cymene as a possible antiviral, alone, or in combination with other agents, in a broad spectrum of RNA viruses, from SARS-CoV-2 to influenza A infections.

Carvacrol improves pulmonary function tests, oxidant/antioxidant parameters and cytokine levels in asthmatic patients: A randomized, double-blind, clinical trial

BACKGROUND

Carvacrol effects on inflammatory mediators, lung pathology and tracheal responsiveness were indicated in animal models of pulmonary diseases.

PURPOSE

To evaluate carvacrol effects on respiratory symptoms, pulmonary function tests (PFT), oxidative stress markers and cytokine levels in asthmatic patients.

STUDY DESIGN

This study was a randomized, placebo-controlled double-blind, clinical trial.

METHODS

Thirty-three moderate asthmatic patients were divided to the two groups of: placebo group (n = 16) and carvacrol group (1.2 mg/kg/day, n = 17). Prepared capsules were taken for two months along, 3 times/day along with routine medications. Respiratory symptoms, PFT, and oxidative stress markers were evaluated before the treatment (step 0), and one (step I) and two months (step II) after the beginning of the treatment. However, cytokine levels in serum and supernatant of peripheral blood mononuclear cells (PBMC), and their gene expression were evaluated in step 0 and II.

RESULTS

In carvacrol-treated group, respiratory symptoms significantly decreased after one- and two-month treatment with carvacrol compared to pre-treatment values (p < 0.05 to p < 0.001). Compared to step 0, PFT values were significantly increased in step I and II, in treated group with carvacrol (p < 0.05 to p < 0.001). Most oxidative stress markers were improved following carvacrol treatment (p < 0.05 to p < 0.001). Treatment with carvacrol for two-month also significantly improved cytokine levels in serum and supernatant of PBMC, compared to step 0 (p < 0.05 to p < 0.001). However, no significant changes were observed in the above-noted parameters in the placebo group.

CONCLUSION

Due to anti-inflammatory and antioxidant effect, carvacrol could be suggested as a therapeutic agent for asthma.

Biological Activities of Two Essential Oils from Pogostemon cablin and Eupatorium fortunei and Their Major Components against Fungi Isolated from Panax notoginseng

Panax notoginseng (Burkill) F.H.Chen (Araliaceae), of which the dry root and rhizome are precious traditional Chinese medicine, suffers severely from diseases during planting. Essential oils (EOs) with antimicrobial activity are a possibility for the development of green pesticides. We extracted EOs from Pogostemon cablin (Blanco) Benth. and Eupatorium fortunei Turcz., respectively and tested their inhibitory rates on fungi isolated from diseased P. notoginseng by the Oxford cup method. The compounds of the EO were identified by GC/MS and the minimum inhibitory concentrations (MICs) of the EOs and their main components were evaluated by the 96-well plate method. We also mixed P. cablin EO, E. fortunei EO and hymexazol in pairs to explore whether their combinations produce stronger antifungal effects than individual components. Finally, we evaluated the effects of the EOs against Fusarium oxysporum in vivo. P. cablin EO and E. fortunei EO exhibited different antifungal activities against fungi, with the inhibitory rates of 21.02 %-100 % and 54.84 %-100 % and MICs of 0.07-0.88 mg/mL and 0.20-1.17 mg/mL, respectively. Pogostone (24.96 %) and thymol (15.64 %) were the major compounds of P. cablin EO and E. fortunei EO, respectively, and they exhibited stronger antifungal activities than EOs, with MICs of 0.008-0.078 mg/mL and 0.12-0.31 mg/mL, respectively. Moreover, hymexazol was mixed with E. fortunei EO, and the inhibitory effect against Cylindrocarpon destructans was enhanced with a synergistic effect. The disease incidence and disease index of EO treatments decreased significantly in vivo. Based on our study, P. cablin EO and E. fortunei EO have great potential to be developed into green fungicides for use in agriculture to control diseases of P. notoginseng.

Anticonvulsant Essential Oils and Their Relationship with Oxidative Stress in Epilepsy

Epilepsy is a most disabling neurological disorder affecting all age groups. Among the various mechanisms that may result in epilepsy, neuronal hyperexcitability and oxidative injury produced by an excessive formation of free radicals may play a role in the development of this pathology. Therefore, new treatment approaches are needed to address resistant conditions that do not respond fully to current antiepileptic drugs. This paper reviews studies on the anticonvulsant activities of essential oils and their chemical constituents. Data from studies published from January 2011 to December 2018 was selected from the PubMed database for examination. The bioactivity of 19 essential oils and 16 constituents is described. Apiaceae and Lamiaceae were the most promising botanical families due to the largest number of reports about plant species from these families that produce anticonvulsant essential oils. Among the evaluated compounds, β-caryophyllene, borneol, eugenol and nerolidol were the constituents that presented antioxidant properties related to anticonvulsant action. These data show the potential of these natural products as health promoting agents and use against various types of seizure disorders. Their properties on oxidative stress may contribute to the control of this neurological condition. However, further studies on the toxicological profile and mechanism of action of essential oils are needed.

Oregano Essential Oil Attenuates RAW264.7 Cells from Lipopolysaccharide-Induced Inflammatory Response through Regulating NADPH Oxidase Activation-Driven Oxidative Stress

Oregano is an aromatic plant widely distributed throughout the Mediterranean area and in Asia. Recent studies have revealed that the anti-inflammatory effect of essential oil in this plant. However, the mechanisms underlying the therapeutic potential have not been well elucidated. This study determined whether oregano essential oil (OEO) exerts an anti-inflammatory effect on lipopolysaccharide (LPS)-treated murine macrophage cells (RAW264.7 cells) in vitro and elucidated the possible underlying molecular mechanisms. The results showed that OEO (2.5–10 μg/mL) inhibited the expression and secretion of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in RAW264.7 cells treated with LPS (1 μg/mL). Consistent with the pro-inflammatory gene expression, the OEO treatment efficiently reduced the LPS-induced activation of mitogen-activated protein kinase, protein kinase B, and nuclear factor κB in RAW264.7 cells. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibition in Nox2 protein-silenced cells attenuated the mRNA expression of IL-1β, IL-6, and TNF-α in the LPS-induced RAW264.7 cells. The OEO inhibited the LPS-induced elevation of NADPH oxidase and oxidative stress. This result suggests that LPS induces RAW264.7 cell inflammation through the NADPH oxidase-mediated production of reactive oxygen species (ROS). In conclusion, OEO protects against the LPS-induced RAW264.7 cell inflammatory response through the NADPH oxidase/ROS pathway.

Pharmacological Properties and Molecular Mechanisms of Thymol: Prospects for Its Therapeutic Potential and Pharmaceutical Development

Thymol, chemically known as 2-isopropyl-5-methylphenol is a colorless crystalline monoterpene phenol. It is one of the most important dietary constituents in thyme species. For centuries, it has been used in traditional medicine and has been shown to possess various pharmacological properties including antioxidant, free radical scavenging, anti-inflammatory, analgesic, antispasmodic, antibacterial, antifungal, antiseptic and antitumor activities. The present article presents a detailed review of the scientific literature which reveals the pharmacological properties of thymol and its multiple therapeutic actions against various cardiovascular, neurological, rheumatological, gastrointestinal, metabolic and malignant diseases at both biochemical and molecular levels. The noteworthy effects of thymol are largely attributed to its anti-inflammatory (via inhibiting recruitment of cytokines and chemokines), antioxidant (via scavenging of free radicals, enhancing the endogenous enzymatic and non-enzymatic antioxidants and chelation of metal ions), antihyperlipidemic (via increasing the levels of high density lipoprotein cholesterol and decreasing the levels of low density lipoprotein cholesterol and low density lipoprotein cholesterol in the circulation and membrane stabilization) (via maintaining ionic homeostasis) effects. This review presents an overview of the current in vitro and in vivo data supporting thymol's therapeutic activity and the challenges concerning its use for prevention and its therapeutic value as a dietary supplement or as a pharmacological agent or as an adjuvant along with current therapeutic agents for the treatment of various diseases. It is one of the potential candidates of natural origin that has shown promising therapeutic potential, pharmacological properties and molecular mechanisms as well as pharmacokinetic properties for the pharmaceutical development of thymol.

Immunomodulatory effect of characterized extract of Zataria multiflora on Th1, Th2 and Th17 in normal and Th2 polarization state

The effect of the extract of Zataria multiflora (Z. multiflora) on IFN-γ, FOXP3, IL-4, TGF-β, and IL-17 gene expression was evaluated in cultured splenocytes obtained from control, nontreated asthma or sensitized mice (group S), Sensetized animals treated with dexamethasone or three concentrations of Z. multiflora extract (200, 400 and 800 μg/ml) (n = 6, for each group). IFN-γ and FOXP3 gene expressions were significantly decreased (P < 0.001 for both cases) but IL-4 (P < 0.001) and IL-17 (P < 0.05) were increased in group S compared to control group. Z. Multiflora extract 800 μg/ml, significantly upregulated IFN-γ gene expression (P < 0.01) and its 400 and 800 μg/ml concentrations increased FOXP3 gene expression (P < 0.05 and P < 0.001, respectively) compared to group S. Z. multiflora extract at all concentrations (200, 400 and 800 μg/ml) decreased TGF-β gene expression and its lowest concentration significantly reduced IL-17 gene expression compared to group S (P < 0.001 for all cases). Only IL-4 and TGF-β gene expression was significantly decreased following treatment with dexamethasone (P < 0.001 for both cases). The results indicated an increase in IFN-γ and FOXP3 but decrease in TGF-β and IL-17 gene expression profile in sensitized splenocytes treated with the extract, which might be partially due to the presence of one of its constituent, carvacrol.

Kazakh Ziziphora Species as Sources of Bioactive Substances

Ziziphora species represent the prototypical example of the Lamiaceae family. The phytochemicals present in Ziziphora include monoterpenic essential oils, triterpenes and phenolic substances belonging to the flavonoids. In Kazakh traditional medicine, Ziziphora species possess several medicinal uses. In particular, Z. bungeana Lam. and Z. clinopodioides Lam. are used for the treatment of illnesses related to the cardiovascular system or to combat different infections. Unfortunately, the majority of the information about the complex Ziziphora species is only available in Russian and Chinese language, therefore, we decided gather all available information on Kazakhstan Ziziphora, namely its content compounds, medicinal uses and published patents, to draw the attention of scientists to this very interesting plant with high medicinal potential.

Carvacrol inhibits atherosclerotic neointima formation by downregulating reactive oxygen species production in vascular smooth muscle cells

OBJECTIVE

Carvacrol (2-methyl-5-(1-methylethyl) phenol), a cyclic monoterpene, exerts protective activities in a variety of pathological states including tumor growth, inflammation, and oxidative stress. However, it is unknown whether carvacrol affects events in vascular cells during the development of atherosclerotic neointima. We investigated the effects of carvacrol on the migration and proliferation of rat aortic smooth muscle cells (RASMCs) and on vascular neointima formation.

METHODS AND RESULTS

Carvacrol significantly inhibited platelet-derived growth factor (PDGF)-BB-stimulated RASMC migration and proliferation in a concentration-dependent manner. Cell viability was not affected by treatment with carvacrol. Carvacrol attenuated the expression of NADPH oxidase (NOX) 1 and the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase 1/2 in response to PDGF-BB. Moreover, carvacrol suppressed the PDGF-BB-stimulated generation of H2O2 and inhibited the activity of NOX in RASMCs. Treatment with carvacrol inhibited PDGF-BB-induced aortic sprout outgrowth, balloon injury-evoked vascular neointima formation, and expression of proliferating cell nuclear antigen in the neointima.

CONCLUSION

These findings indicate that carvacrol inhibits migration and proliferation of RASMCs by suppressing the reactive oxygen species-mediated MAPK signaling pathway in these cells, thereby attenuating vascular neointimal formation. Carvacrol may be a promising agent for preventing vascular restenosis or atherosclerosis.

The extract of Zataria multiflora affect tracheal responsiveness, serum levels of NO, nitrite, PLA2, TP and histamine in sensitized Guinea pigs

ETHNOPHARMACOLOGICAL RELEVANCE

Different therapeutic effects for Zataria multiflora have been described in Iranian traditional medicine. In addition anti-inflammatory and anti-oxidant effects of this plant were previously described. The effect of the extract of Zataria multiflora on tracheal responsiveness (TR) and inflammatory mediators of sensitized guinea pigs was examined.

MATERIALS AND METHODS

Five groups of sensitized guinea pigs to ovalbumin (OA) were given drinking water alone, drinking water containing three concentrations of the extract and dexamethasone. TR to methacholine and OA, serum levels of NO, nitrite, PLA2, TP and histamine were measured (n=6, for each groups).

RESULTS

TR to methacholine and OA, serum levels of NO, nitrite, PLA2, TP and histamine were increased in sensitized animals compared to control group (p<0.05 to p<0.001). Treatment of sensitized animals with dexamethasone and most concentration of the extract lead to significantly decrease in all measured parameters compared to sensitized group (p<0.05 to p<0.001) except TP and histamine levels in treated group with dexamethasone.

CONCLUSION

These results showed a preventive effect of the extract of Zataria multiflora on tracheal responsiveness, serum level of NO, nitrite, total protein, PLA2 and histamine in sensitized guinea pigs which was equal or even more potent than dexamethasone at used concentrations.

Zataria multiflora Boiss. (Shirazi thyme)--an ancient condiment with modern pharmaceutical uses

ETHNOPHARMACOLOGICAL RELEVANCE

Zataria multiflora Boiss. (ZM) is a thyme-like plant belonging to the Lamiaceae family that grows wild only in Iran, Pakistan and Afghanistan. This plant with the vernacular name of Avishan-e-Shirazi (Shirazi thyme) in Iran is a valuable medicinal and condimental plant. It has several traditional uses as an antiseptic, carminative, stimulant, diaphoretic, diuretic, anesthetic, anti-spasmodic and analgesic.

AIM OF THE STUDY

This paper reviews the ethnopharmacology, pharmacology, toxicology, modern pharmaceutical uses and phytochemistry of Zataria multiflora, and highlights the gaps in our knowledge deserving further research.

MATERIALS AND METHODS

All relevant databases were searched for the terms "Zataria", "Zataria multiflora", "Shirazi thyme" and "Iranian thyme" without limitation up to 24th October 2012. Information on Zataria multiflora was collected via electronic search using Pubmed, Scopus, Web of Science and SID (for articles in Persian language), and local books on ethnopharmacology.

RESULTS

ZM has played an important role in Iranian traditional medicine. In light of the modern pharmacological and clinical investigations, ZM is a valuable medicinal and condimental plant that has anti-microbial, antioxidative, anti-inflammatory, spasmolytic and anti-nociceptive properties. The oil of ZM contains high percentages of oxygenated monoterpenes, in particular thymol and carvacrol, and exhibits excellent anti-microbial properties.

CONCLUSIONS

Overall, antimicrobial property appears to be the most interesting studied biological effect of ZM. The lack of a comprehensive phytochemical analysis of ZM is an important limitation that can be noted regarding most of the previous studies.