Safety and tolerability of carvacrol in healthy subjects: a phase I clinical study.

This study was designed to assess safety and tolerability of carvacrol in healthy individuals. Subjects were randomly divided into two groups receiving 1 and 2 mg/kg/day carvacrol. Before and after carvacrol administration, routine blood and urine laboratory tests and spirometry were performed for all participants. The results showed that one-month treatment with carvacrol did not significantly affect the measured variables. In the group receiving 1 mg/kg/day carvacrol, calcium, erythrocyte sedimentation rate (ESR), mean cell volume (MCV), hemoglobin (Hb), and hematocrit (HCT) levels were significantly reduced but creatinine phosphokinase (CPK) was significantly increased, after treatment compared to baseline values (p < 0.05-p < 0.001). There was significant reductions in high-density lipoprotein cholesterol (HDL), total bilirubin, amylase, iron, red blood cells (RBC) count, and HCT after one-month treatment with 2 mg/kg/day carvacrol compared to pretreatment values (p < 0.05-p < 0.01). Although, triglyceride (TG), phosphorus, lactate dehydrogenase (LDH), prothrombin time (PT), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were significantly increased after treatment with carvacrol 1 mg/kg/day (p < 0.05-p < 0.001), all post-treatment measured parameters were within normal range. Treatment with carvacrol 2 mg/kg/day for one month increased FEV1 (p < 0.05). Nevertheless, there was no significant difference in measured variables except LDH, MCH, MCHC, and MCV (p < 0.05-p < 0.01), between the two groups. The results of this phase I study regarding carvacrol effects on healthy subjects, showed clinical safety and tolerability for this agent.

Transient Receptor Potential Ankyrin-1 and Vanilloid-3 Differentially Regulate Endoplasmic Reticulum Stress and Cytotoxicity in Human Lung Epithelial Cells After Pneumotoxic Wood Smoke Particle Exposure.

This study investigated the roles of transient receptor potential (TRP) ankyrin-1 (TRPA1) and TRP vanilloid-3 (TRPV3) in regulating endoplasmic reticulum stress (ERS) and cytotoxicity in human bronchial epithelial cells (HBECs) treated with pneumotoxic wood smoke particulate matter (WSPM) and chemical agonists of each channel. Functions of TRPA1 and TRPV3 in pulmonary epithelial cells remain largely undefined. This study shows that TRPA1 activity localizes to the plasma membrane and endoplasmic reticulum (ER) of cells, whereas TRPV3 resides primarily in the ER. Additionally, treatment of cells using moderately cytotoxic concentrations of pine WSPM, carvacrol, and other TRPA1 agonists caused ERS as a function of both TRPA1 and TRPV3 activities. Specifically, ERS and cytotoxicity were attenuated by TRPA1 inhibition, whereas inhibiting TRPV3 exacerbated ERS and cytotoxicity. Interestingly, after treatment with pine WSPM, TRPA1 transcription was suppressed, whereas TRPV3 was increased. TRPV3 overexpression in HBECs conferred resistance to ERS and an attenuation of ERS-associated cell cycle arrest caused by WSPM and multiple prototypical ERS-inducing agents. Alternatively, short hairpin RNA-mediated knockdown of TRPV3, like the TRPV3 antagonist, exacerbated ERS. This study reveals previously undocumented roles for TRPA1 in promoting pathologic ERS and cytotoxicity elicited by pneumotoxic WSPM and TRPA1 agonists, and a unique role for TRPV3 in fettering pathologic facets of the integrated ERS response. SIGNIFICANCE STATEMENT: These findings provide new insights into how wood smoke particulate matter and other transient receptor potential ankyrin-1 (TRPA1) and transient receptor potential vanilloid-3 (TRPV3) agonists can affect human bronchial epithelial cells and highlight novel physiological and pathophysiological roles for TRPA1 and TRPV3 in these cells.

Carvacrol and Thymol Attenuate Cytotoxicity Induced by Amyloid ß25-35 via Activating Protein Kinase C and Inhibiting Oxidative Stress in PC12 Cells.

Background: Our previous findings indicated that carvacrol and thymol alleviate cognitive impairments caused by Aß in rodent models of Alzheimer's disease (AD). In this study, the neuroprotective effects of carvacrol and thymol against Aß25-35-induced cytotoxicity were evaluated, and the potential mechanisms were determined. Methods: PC12 cells were pretreated with Aß25-35 for 2 h, followed by incubation with carvacrol or thymol for additional 48 h. Cell viability was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. A flurospectrophotometer was employed to observe the intracellular reactive oxygen species (ROS) production. Protein kinase C (PKC) activity was analyzed using ELISA. Results: Our results indicated that carvacrol and thymol could significantly protect PC12 cells against Aß25-35-induced cytotoxicity. Furthermore, Aß25-35 could induce intracellular ROS production, while carvacrol and thymol could reverse this effect. Moreover, our findings showed that carvacrol and thymol elevate PKC activity similar to Bryostatin-1, as a PKC activator. Conclusion: This study provided the evidence regarding the protective effects of carvacrol and thymol against Aß25­35-induced cytotoxicity in PC12 cells. The results suggested that the neuroprotective effects of these compounds against Aß25-35 might be through attenuating oxidative damage and increasing the activity of PKC as a memory-related protein. Thus, carvacrol and thymol were found to have therapeutic potential in preventing or modulating AD.

p-Cymene Modulate Oxidative Stress and Inflammation in Murine Macrophages: Potential Implication in Atherosclerosis.

BACKGROUND: p-Cymene (p-CYM) is a common chemical used in air fresheners. OBJECTIVE: The study was designed to investigate the molecular effect of p-CYM on macrophages. MATERIALS AND METHODS: Macrophages (RAW 264.7) were treated with p-CYM (50 uM/L, 150 uM/L and 250 uM/L) for 6 hours, and 24 hours). Gene involved in inflammation, such as the Tumor Necrosis Factor-alpha (TNF-α), and the Monocyte Chemoattractant Protein-1 (MCP-1) and other genes known for their antioxidant activity such as the Paraoxonase 1 (PON-1) were analyzed. RESULTS: Cells treated with p-CYM have shown 30% up-regulation of MCP-1 after 24 hour of exposure; and also a differential up-regulation of TNF-α. However, treatment with p-CYM has resulted in a considerable (37%) dose-dependent downregulation of PON-1 after 24 hours of exposure. PON-1 is known for its antioxidant properties protecting High-Density Lipoproteins (HDL) from oxidation. CONCLUSION: Our findings demonstrate that exposure to p-CYM over time promotes oxidative stress by downregulating antioxidants genes as shown in PON-1 and also stimulates inflammation, a key process during the initiation and progression of atherosclerosis.

Inhibition of the Warm Temperature-Activated Ca2+-Permeable Transient Receptor Potential Vanilloid TRPV3 Channel Attenuates Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by cutaneous lesions and intense pruritus. The warm temperature-activated Ca2+-permeable transient receptor potential vanilloid (TRPV)3 channel is abundantly expressed in keratinocytes, and gain-of-function mutations of TRPV3 cause skin lesions and pruritus in rodents and humans, suggesting an involvement of TRPV3 in the pathogenesis of AD. Here we report that pharmacological and genetic inhibition of TRPV3 attenuates skin lesions and dermatitis in mice. We found that TRPV3 proteins, together with inflammatory factors tumor necrosis factor (TNF)-α and interleukin (IL)-6, were upregulated in the skin of mice in a AD-like model induced by topical application of chemical 2,4-dinitrofluorobenzene, as detected by Western blot analysis and immunostaining assays. Pharmacological activation of TRPV3 by channel agonist and skin sensitizer carvacrol resulted in the development of AD in wild-type mice but not in TRPV3 knockout mice. Furthermore, inhibition of TRPV3 by natural osthole reversed the severity of inflammatory dorsal skin and ear edema in a dose-dependent manner and also decreased expression of inflammatory factors TNF-α and IL-6. Taken together, our findings demonstrate the involvement of overactive TRPV3 in the progressive pathology of AD in mice, and topical inhibition of TRPV3 channel function may represent an effective option for preventing and treating AD or inflammatory skin diseases. SIGNIFICANCE STATEMENT: The overactive transient receptor potential vanilloid TRPV3 channel is critically involved in the pathogenesis of atopic dermatitis. Inhibition of TRPV3 channel function by topical natural osthole may represent an effective therapy for management of atopic dermatitis aimed at preventing or alleviating skin lesions and severe itching.

The effect of carvacrol on inflammatory mediators and respiratory symptoms in veterans exposed to sulfur mustard, a randomized, placebo-controlled trial.

BACKGROUND: The aim of this study was to evaluate the effect of carvacrol on serum level of inflammatory mediators and respiratory symptoms in the veterans exposed to sulfur mustard (SM). METHODS: Twenty-one patients who were exposed to SM more than two decades' ago were divided to placebo and carvacrol (1.2 mg/kg/day) treated groups. Serum levels of Tumor Necrosis Factor-α (TNF-α), Monocyte chemotactic protein-1 (MCP-1), Vascular endothelial growth factor (VEGF), Epidermal growth factor (EGF), forced expiratory volume-one second (FEV1) and respiratory symptoms including; Chest wheeze (CW), night wheeze (NW), night cough (NC) and cough and wheeze during exercise (ECW) were assessed at the baseline (step 0), one and two months after starting treatment (step I and II, respectively). FINDINGS: FEV1 value was significantly increased in carvacrol treated group in step II compared to step 0 (p < 0.001) and also increased in step II compared to step I (p < 0.05). The respiratory symptoms including; CW and NW was significant decreased in carvacrol treated group in step I and II compared to step 0 (p < 0.01 to p < 0.001), NC and ECW were significantly decreased only in step II compared to step 0 (p < 0.01, for both cases). The serum levels of TNF-α, EGF and VEGF were decrease in carvacrol treated group in step I and II compared to step 0 (p < 0.05 to p < 0.001). The serum level of MCP-1 was decrease in carvacrol treated group only in the step II compared to step 0 (p < 0.05). INTERPRETATION: Two months' treatment with carvacrol reduced inflammatory cytokine and chemokine while increased anti-inflammatory cytokines and improved respiratory symptom and FEV1 value in SM exposed patients. CLINICAL TRIALS REGISTRY NUMBER: This trial was registered under IRCT2014031617020N1 at http://www.irct.ir/.