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

Neuroprotective role of Carvacrol via Nrf2/HO-1/NLRP3 axis in Rotenone-induced PD mice model

Parkinson's disease (PD) is a multifactorial neurodegenerative disorder whose cause is unclear. Neuroinflammation is recognized as one of the major pathogenic mechanisms involved in the development and progression of PD. NLRP3 inflammasome is the most widely studied inflammatory mediator in various diseases including PD. Several phytoconstituents have shown neuroprotective role in PD. Carvacrol is a phenolic monoterpene commonly found in the essential oils derived from plants belonging to Lamiaceae family. It is well known for its anti-inflammatory and antioxidant properties and has been widely explored in several diseases. In this study, we explored the role of Carvacrol in suppressing neuroinflammation by regulating NLRP3 inflammasome through Nrf2/HO-1 axis and subsequently, inflammatory cytokines like IL-1β, IL-18 in Rotenone induced PD mice model. Three doses (25 mg/kg, 50 mg/kg, 100 mg/kg p.o.) of Carvacrol were administered to, respectively, three groups (LD, MD, HD), one hour after administration of Rotenone (1.5 mg/kg, i.p.), every day, for 21 days. Treatment with Carvacrol ameliorated the motor impairment caused by Rotenone. It alleviated neurotoxicity and reduced inflammatory cytokines. Further, Carvacrol also alleviated oxidative stress and increased antioxidant enzymes. From these results, we show that Carvacrol exerts neuroprotective effects in PD via anti-inflammatory and antioxidant mechanisms and could be a potential therapeutic option in PD.

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.

Plant Monoterpenes and Essential Oils as Potential Anti-Ageing Agents: Insights from Preclinical Data

Ageing is a natural process characterized by a time-dependent decline of physiological integrity that compromises functionality and inevitably leads to death. This decline is also quite relevant in major human pathologies, being a primary risk factor in neurodegenerative diseases, metabolic disorders, cardiovascular diseases and musculoskeletal disorders. Bearing this in mind, it is not surprising that research aiming at improving human health during this process has burst in the last decades. Importantly, major hallmarks of the ageing process and phenotype have been identified, this knowledge being quite relevant for future studies towards the identification of putative pharmaceutical targets, enabling the development of preventive/therapeutic strategies to improve health and longevity. In this context, aromatic plants have emerged as a source of potential bioactive volatile molecules, mainly monoterpenes, with many studies referring to their anti-ageing potential. Nevertheless, an integrated review on the current knowledge is lacking, with several research approaches studying isolated ageing hallmarks or referring to an overall anti-ageing effect, without depicting possible mechanisms of action. Herein, we aim to provide an updated systematization of the bioactive potential of volatile monoterpenes on recently proposed ageing hallmarks, and highlight the main mechanisms of action already identified, as well as possible chemical entity-activity relations. By gathering and categorizing the available scattered information, we also aim to identify important research gaps that could help pave the way for future research in the field.

Effect of dietary interventions on markers of type 2 inflammation in asthma: A systematic review

INTRODUCTION

Type 2 (T2) inflammation is a key mechanism in the pathophysiology of asthma. Diet may have immunomodulatory effects, and a role for diet in T2 inflammation has been suggested in the literature. Indeed, diet and food allergies play a role in children with atopic asthma, but less is known about diet in relation to adult asthma, which is often non-atopic.

OBJECTIVE

To review the effect of dietary interventions on markers of T2 inflammation in adults with asthma.

METHODS

The databases PubMed, Embase, Cochrane Library, and CINAHL were searched for eligible studies until December 2022. We included studies of all types of foods, nutrients, diets or supplements, either as an exposure or as an intervention, in adults and adolescents with asthma. Outcomes of interest included the T2 biomarkers FeNO, eosinophils, IL-4, IL-5, IL-13, eosinophil cationic protein and eosinophil peroxidase. The methodological quality of eligible studies was systematically evaluated, and the results were summarised according to dietary clusters.

RESULTS

The systematic search identified studies on the dietary clusters antioxidants (n = 14), fatty acids, (n = 14), Mediterranean-style diets (n = 5), phytotherapy (n = 7), prebiotics & probiotics (n = 8), vitamin D (n = 7), and other dietary factors (n = 5). Studies within the phytotherapy and omega-3 poly-unsaturated fatty acids (PUFA) clusters showed possible improvements in T2 inflammation. Furthermore, we found little evidence for an effect of antioxidants, prebiotics & probiotics, and Mediterranean-style diets on T2 inflammation. However, heterogeneity in study protocols, methodological shortcomings and limited power of almost all studies make it difficult to fully determine the impact of different dietary approaches on T2 inflammation in asthma.

CONCLUSIONS

Overall, the current evidence does not support a specific dietary intervention to improve T2 inflammation in asthma. Interventions involving phytotherapy and omega-3 PUFA currently have the best evidence and warrant further evaluation in well-designed and adequately powered studies, while taking into account T2-high phenotypes of asthma.

Anti-Inflammatory and Antimicrobial Properties of Thyme Oil and Its Main Constituents

Thyme oil (TO) is derived from the flowers of various plants belonging to the genus Thymus. It has been used as a therapeutic agent since ancient times. Thymus comprises numerous molecular species exhibiting diverse therapeutic properties that are dependent on their biologically active concentrations in the extracted oil. It is therefore not surprising that oils extracted from different thyme plants present different therapeutic properties. Furthermore, the phenophase of the same plant species has been shown to yield different anti-inflammatory properties. Given the proven efficacy of TO and the diversity of its constituents, a better understanding of the interactions of the various components is warranted. The aim of this review is to gather the latest research findings regarding TO and its components with respect to their immunomodulatory properties. An optimization of the various components has the potential to yield more effective thyme formulations with increased potency.

Carvacrol and HP-β-Cyclodextrin Complexes: Extensive Characterization and Potential Cytotoxic Effect in Human Colorectal Carcinoma Cells

The aim of this study was to obtain solid carvacrol-cyclodextrin (CD) complexes for use in the pharmaceutical industry. To this end, the complexation of carvacrol at different pH values was studied in detail, to determine the type of CD and the reaction environment that supported the highest amount of encapsulated carvacrol. Evidence of the capability of hydroxypropyl-β-cyclodextrins (HP-β-CD) to form inclusion complexes with carvacrol (K_C = 5042 ± 176 L mol^-1) and more high complexation efficiency (2.824) was demonstrated for HP-β-CDs using two different energy sources, ultrasound (US) (K_C = 8129 ± 194 L mol^-1 24 h) and microwave irradiation (MWI) (K_C = 6909 ± 161 L mol^-1), followed by spraying the resulting solution in a spray dryer. To confirm complex formation, the complexes were characterized using various instrumental methods to corroborate the carvacrol incorporation into the hydrophobic cavity of HP-β-CD. The obtained carvacrol solid complexes were analyzed by 1H nuclear magnetic resonance (¹H-NMR) and 2D nuclear magnetic resonance (ROSEY), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR) characterization. The structures of the resulting complexes were also characterized by molecular modeling. Furthermore, 1 mM HP-β-CD-carvacrol complex has been shown to reduce cell proliferation in HCT-116 colorectal cancer cells by 43%, much more than in a healthy lung fibroblast MRC-5 cell line (11%).

The effect of two-month treatment with Zataria multiflora on inflammatory cytokines, pulmonary function testes and respiratory symptoms in patients with chronic obstructive pulmonary disease (COPD)

ETHNOPHARMACOLOGICAL RELEVANCE

Zataria multiflora Boiss. (Z. multiflora) is a valuable medicinal plant that has been used in Iranian traditional and folk medicine as an antiseptic, carminative, diaphoretic, diuretic, anti-spasmodic and analgesic herbal medicine. This plant has been also used to relieve cough in common cold and respiratory tract disorders. The previous studies reported the pharmacological effects of Z. multiflora such as anti-inflammatory and anti-oxidant properties in respiratory disorders in animal models and clinical studies.

AIM OF THE STUDY

The effects of Z. multiflora extract on inflammatory cytokines, pulmonary function tests (PFT), and respiratory symptoms in chronic obstructive pulmonary diseases (COPD) patients were investigated.

MATERIALS AND METHODS

COPD patients (41 cases) were divided to three groups including placebo group (P) and groups received 3 and 6 mg/kg/day Z. multiflora extract (Z3 and Z6) for two months. Inflammatory cytokines, PFT values, and respiratory symptoms were assessed before treatment (stage 0), one (stage I) and two (stage II) months after treatment.

RESULTS

Serum levels of TNF-α and IL-8 were significantly decreased after two months treatment compared to baseline values in Z3 and Z6 groups. The PFT values including forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were significantly increased during two months treatment with Z3 and Z6. The peak expiratory flow (PEF) was also significantly increased after one-month treatment with Z6. The respiratory symptoms including cough, chest tightness, modified medical research council (mMRC) dyspnea scale were significantly improved after one and two treatments with both doses of Z. multiflora compared to baseline values.

CONCLUSION

The results suggest the potential therapeutic effect of Z. multiflora in COPD patients through reduction of inflammatory cytokines, increasing PFT values and improvement of respiratory symptoms.

Experimental and clinical evidence on the effect of carvacrol on respiratory, allergic, and immunologic disorders: A comprehensive review

Carvacrol (CAR) showed various pharmacological and therapeutic effects in different disorders. In the current article, the experimental and clinical effects of CAR on respiratory, allergic, and immunologic disorders are described. Various databases, including PubMed, Science Direct, and Scopus, were searched regarding the effects of CAR on respiratory and allergic disorders until the end of October 2021. CAR showed the relaxant effect, with various possible mechanisms suggesting the bronchodilatory effect in obstructive pulmonary diseases. The preventive effects of CAR on experimental animal models of respiratory diseases were shown through mechanisms such as antioxidant, immunomodulatory, and anti-inflammatory. CAR also showed therapeutic potential on lung cancer, lung infections, and allergic and immunologic disorders. Clinical studies also revealed therapeutic effects of CAR on asthma, sulfur-mustard-induced lug disorders, and some other allergic and immunologic diseases. Pharmacological and therapeutic effects of CAR indicate possible remedy effects of this agent in the treatment of respiratory, allergic, and immunologic diseases.

The Effects of a Transgelin-2 Agonist Administered at Different Times in a Mouse Model of Airway Hyperresponsiveness

Airway hyperresponsiveness (AHR) is one of the most important features of asthma. Our previous study showed that inhaled transgelin-2 agonist, TSG12, effectively reduced pulmonary resistance in a mouse model of asthma in a dose-dependent manner. However, the optimal administration time of TSG12 to reduce AHR and the pharmacological effects are still unclear. In this study, the effects of TSG12 inhalation before and during AHR occurrence were examined. The results showed that the pulmonary resistance was reduced by 57% and the dynamic compliance was increased by 46% in the TSG12 Mch group (atomize TSG12 10 min before methacholine, p < 0.05 vs. model). The pulmonary resistance was reduced by 61% and the dynamic compliance was increased by 47% in the TSG12 + Mch group (atomize TSG12 and methacholine together, p < 0.05 vs. model). Quantitative real-time PCR showed that the gene expression levels of transgelin-2, myosin phosphatase target subunit-1, and myosin light chain were up-regulated by 6.4-, 1.9-, and 2.8-fold, respectively, in the TSG12 Mch group. The gene expression levels of transgelin-2, myosin phosphatase target subunit-1, and myosin light chain were up-regulated by 3.2-, 1.4-, and 1.9-fold, respectively, in the TSG12 + Mch group. The results suggested that TSG12 effectively reduces pulmonary resistance when TSG12 inhalation occurred both before and during AHR occurrence. Gene expression levels of transgelin-2 and myosin light chain were significantly up-regulated when TSG12 inhalation occurred before AHR occurrence. This study may provide a basis for the administration time of TSG12 for asthma treatment in the future.

Zataria multiflora extract influenced asthmatic patients by improving respiratory symptoms, pulmonary function tests and lung inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Anti-inflammatory and anti-oxidant effects of Zataria multiflora Boiss (Z. multiflora) were reported in previous studies which is using in traditional and modern medicine. This plant is traditional used as an anti-tussive agent and for the management of respiratory disorders.

AIM OF THE STUDY

The preventive effect of the extract of leaves and stems of Z. multiflora on respiratory symptoms, pulmonary function tests, hematological indices, high sensitivity C-reactive protein (hs-CRP), level of interleukin-10 (IL-10) in the serum and supernatant of cultured peripheral blood mononuclear cells (PBMC) and gene expression of IL-10 in these cells in asthmatic patients was studied.

MATERIALS AND METHODS

36 asthmatic patients in three groups (randomly divided) of placebo group (P), two groups treated with 5 and 10 mg/kg/day doses of Z. multiflora (Z5 and Z10) for two months completed the study. Drugs were administered double-blindly and different variables were assessed before and after (one and two months) starting treatment including respiratory symptoms, pulmonary function tests (PFT), hematological indices, hs-CRP, serum and supernatant levels as well as gene expression of IL-10.

RESULTS

Two months treatment with Z5 and Z10 led to significant reduction of respiratory symptoms (p < 0.05 to p < 0.001). Pulmonary function test values in treated groups were also significantly increased two months after starting treatment (p < 0.05 to p < 0.001). Total WBC, monocytes and eosinophils were also decreased in treated groups with the extract at the end of study period (p < 0.05 to p < 0.01). Hemoglobin and hematocrit in Z10 treated group (p < 0.05 and p < 0.01, respectively) and mean corpuscular volume (MCV) in both treated groups (p < 0.05 to p < 0.01) were significantly reduced. In addition, the level of hs-CRP in both treated groups was significantly reduced after two months (p < 0.05 to p < 0.01). IL-10 concentration in Z10 treated group in supernatant of PBMC was also significantly enhanced (p < 0.01). All comparisons were made compared to the baseline (beginning of the treatment) values.

CONCLUSION

Z. multiflora improved respiratory symptoms and increased pulmonary function tests in asthmatic patients. In addition, the plant was effective in decrement of inflammatory cells and hs-CRP as well as enhanced IL-10. Therefore, the plant showed possible preventive therapeutic effect on asthma.

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.

Systemic inflammation and oxidative stress induced by inhaled paraquat in rat improved by carvacrol, possible role of PPARγ receptors

Control rats were exposed to saline aerosol, two groups were exposed to paraquat (PQ), 27 (PQ-L) and 54 (PQ-H) mg/m³ aerosols and six groups were treated with carvacrol, 20 (C-L) and 80 (C-H) mg/kg/day, pioglitazone, 5 (Pio-L) and 10 (Pio-H) mg/kg/day, C-L+Pio-L and dexamethasone, 0.03 mg/kg/day, for 16 days after the end of exposure to PQ-H. Different variables were measured after the end of treatment period. Total and differential white blood cells counts, nitrite, malondialdehyde, interleukin (IL)-10, and interferon-gamma levels were significant increased, but thiol, superoxide dismutase, catalase, IL-17, and tumor necrosis factor alpha were decreased in the blood due to both doses of PQ (p < 0.05-p < 0.001). Most measured parameters were significantly improved in treated groups with both doses of carvacrol, pioglitazone, the combination of C-L+Pio-L and dexamethasone compared to PQ-H group (p < 0.05-p < 0.001). Treatment with C-L+Pio-L showed significantly higher effects compared to each one alone (p < 0.05-p < 0.001). Systemic oxidative stress and inflammation due to inhaled PQ were improved by carvacrol and pioglitazone. Higher effects of C-L+Pio-L than each one alone suggests carvacrol modulating PPAR-γ receptors.