The effect of carvacrol on healthy neurons and N2a cancer cells: some biochemical, anticancerogenicity and genotoxicity studies

The recent discovery of a promising pharmacological scaffold derived from carvacrol: A review

Carvacrol, called CA, is a dynamic phytoconstituent characterized by a phenol ring abundantly sourced from various natural reservoirs. This versatile scaffold serves as a pivotal template for the design and synthesis of novel drug molecules, harboring promising biological activities. The active sites positioned at C-4, C-6, and the hydroxyl group (-OH) of CA offer fertile ground for creating potent drug candidates from a pharmacological standpoint. In this comprehensive review, we delve into diverse synthesis pathways and explore the biological activity of CA derivatives. We aim to illuminate the potential of these derivatives in discovering and developing efficacious treatments against a myriad of life-threatening diseases. By scrutinizing the structural modifications and pharmacophore placements that enhance the activity of CA derivatives, we aspire to inspire the innovation of novel therapeutics with heightened potency and effectiveness.

The effects of carvacrol and p-cymene on Aβ1-42 -induced long-term potentiation deficit in male rats

AIMS

Alzheimer's disease (AD) is the most common type of dementia in which oxidative stress plays an important role. In this disease, learning and memory and the cellular mechanism associated with it, long-term potentiation (LTP), are impaired. Considering the beneficial effects of carvacrol (CAR) and p-cymene against AD, their effect was assessed on in vivo hippocampal LTP in the perforant pathway (PP)-dentate gyrus (DG) pathway in an Aβ1-42 -induced rat model of AD.

METHODS

Male Wistar rats were randomly assigned to five groups: sham: intracerebroventricular (ICV) injection of phosphate-buffered saline, Aβ: ICV Aβ1-42 injections, Aβ + CAR (50 mg/kg), Aβ + p-cymene (50 mg/kg), and Aβ + CAR + p-cymene. Administration of CAR and p-cymene was done by gavage daily 4 weeks before and 4 weeks after the Aβ injection. The population spike (PS) amplitude and field excitatory postsynaptic potentials (fEPSP) slope were determined in DG against the applied stimulation to the PP.

RESULTS

Aβ-treated rats exhibited impaired LTP induction in the PP-DG synapses, resulting in significant reduction in both fEPSP slope and PS amplitude compared to the sham animals. Aβ-treated rats consumed either CAR or p-cymene separately (but not their combination), and showed an enhancement in fEPSP slope and PS amplitude of the DG granular cells.

CONCLUSIONS

These data indicate that CAR or p-cymene can ameliorate Aβ-associated changes in synaptic plasticity. Surprisingly, the combination of CAR and p-cymene did not yield the same effect, suggesting a potential interaction between the two substances.

Trachyspermum ammi Bioactives Promote Neuroprotection by Inhibiting Acetylcholinesterase, Aβ-Oligomerization/Fibrilization, and Mitigating Oxidative Stress In Vitro

Neurodegenerative diseases (NDs) are a large category of progressive neurological disorders with diverse clinical and pathological characteristics. Among the NDs, Alzheimer's disease (AD) is the most widespread disease, which affects more than 400 million people globally. Oxidative stress is evident in the pathophysiology of nearly all NDs by affecting several pathways in neurodegeneration. No single drug can manage multi-faceted diseases like NDs. Therefore, an alternative therapeutic strategy is required, which can affect several pathophysiological pathways at a time. To achieve this aim, hexane and ethyl acetate extract from Trachyspermum ammi (Carom) were prepared, and GC/MS identified the bioactive compounds. For the cell-based assays, oxidative stress was induced in SH-SY5Y neuroblastoma cells using hydrogen peroxide to evaluate the neuroprotective potential of the Carom extracts/bioactives. The extracts/bioactives provided neuroprotection in the cells by modulating multiple pathways involved in neurodegeneration, such as alleviating oxidative stress and mitochondrial membrane potential. They were potent inhibitors of acetylcholine esterase enzymes and displayed competitive/mixed-type inhibition. Additionally, anti-Aβ1-42 fibrilization/oligomerization and anti-glycation activities were also analyzed. The multi-faceted neuroprotection shown via Carom/Carvacrol makes it a prospective contender in drug development for NDs.

Assessing the Antioxidant Benefits of Topical Carvacrol and Magnolol Periodontal Hydrogel Therapy in Periodontitis Associated with Diabetes in Wistar Rats

It is well recognized that oxidative stress contributes to chronic stress-induced cytotoxicity, which is a major factor in the progression of many diseases, including periodontitis and diabetes. Formulas based on natural extracts with antioxidant properties are alternative treatment perspectives in the management of such diseases. The aim of our study was to assess how carvacrol and magnolol influence periodontitis associated with diabetes in Wistar rats. Ninety Wistar rats were distributed in nine groups: I-control group; II-diabetes group (D); III-periodontitis group (P); IV-periodontitis and diabetes group (PD); V-periodontitis and diabetes with vehicle alone (PDV); VI-periodontitis and diabetes treated with carvacrol (PDC); VII-periodontitis and diabetes treated with magnolol (PDM); VIII-periodontitis and diabetes treated with carvacrol and magnolol (PDCM); IX-healthy group with vehicle alone (CV). Blood malondialdehyde (MDA) levels and catalase activity levels (CAT) were measured as indicators of oxidative stress and antioxidant capacity, respectively. Where diabetes and periodontitis were induced, MDA was augmented and CAT was depleted significantly. Whether given alone (PDM) or in combination with carvacrol (PDCM), magnolol significantly decreased MDA. Between the PDM group and the PDCM group, there were no notable differences. In Wistar rats with periodontitis related to diabetes, topical use of hydrogels containing magnolol, either alone or in combination with carvacrol, may reduce oxidative stress.

The Antibacterial Effect of Selected Essential Oils and Their Bioactive Constituents on Pseudomonas savastanoi pv. savastanoi: Phytotoxic Properties and Potential for Future Olive Disease Control

Plant pathogenic bacteria pose a significant threat to olive cultivation, leading to substantial economic losses and reduced yield. The efficacy of antimicrobial agents against these pathogens is of great interest for sustainable disease management strategies. As such, the management of olive knot disease is one of the major challenges in olive protection. In the presented study, through a series of in vitro assays, we investigated the antimicrobial effect of six essential oils (EOs) and their most concentrated constituents against causative agent of olive knot disease-Pseudomonas savastanoi pv. savastanoi, highlighting the high potential of Origanum compactum EO and its constituent carvacrol. Carvacrol exhibited the highest potential for practical application, demonstrating membrane disruption as its mechanism of action even at the lowest concentration. The bactericidal effect of antimicrobials was confirmed in a time-kill assay, where concentrations of MIC, 2× MIC, and 4× MIC were evaluated. Some of the applied treatments resulted in inhibition equal or higher than copper-based treatment. Additionally, we assessed the phytotoxicity of carvacrol by foliar application on olive cv. Leccino. The appearance of phytotoxic injuries majorly occurred on the young leaves of olive plants, with the highest proportion of damaged canopy observed when the 2× MIC concentration was applied. Due to its great efficiency against P. savastanoi pv. savastanoi in vitro, these findings highlight the potential of carvacrol as a molecule of interest for the development of environmentally friendly biopesticides. This study also contributes to the advancement of disease management practices in olive cultivation, leading to enhanced crop protection.

Chemoprevention of neuroblastoma: progress and promise beyond uncertainties

Neuroblastoma is the most common extracranial solid tumor in children and comprises one-tenth of all childhood cancer deaths. The current clinical therapy for this deadly disease is multimodal, involving an induction phase with alternating regimens of high-dose chemotherapeutic drugs and load reduction surgery; a consolidation phase with more intensive chemotherapy, radiotherapy, and stem cell transplant; and a maintenance phase with immunotherapy and immune-activating cytokine treatment. Despite such intensive treatment, children with neuroblastoma have unacceptable life quality and survival, warranting preventive measures to regulate the cellular functions that orchestrate tumor progression, therapy resistance, metastasis, and tumor relapse/recurrence. Globally, active efforts are underway to identify novel chemopreventive agents, define their mechanism(s) of action, and assess their clinical benefit. Some chemoprevention strategies (e.g., retinoids, difluoromethylornithine) have already been adopted clinically as part of maintenance phase therapy. Several agents are in the pipeline, while many others are in preclinical characterization. Here we review the classes of chemopreventive agents investigated for neuroblastoma, including cellular events targeted, mode(s) of action, and the level of development. Our review: (i) highlights the pressing need for new and improved chemopreventive strategies for progressive neuroblastoma; (ii) lists the emerging classes of chemopreventive agents for neuroblastoma; and (iii) recognizes the relevance of targeting dynamically evolving hallmark functions of tumor evolution (e.g., survival, differentiation, lineage transformation). With recent gains in the understanding of tumor evolution processes and preclinical and clinical efforts, it is our strong opinion that effective chemopreventive strategies for aggressive neuroblastoma are a near reality.

P53 and taurine upregulated gene 1 promotes the repair of the DeoxyriboNucleic Acid damage induced by bupivacaine in murine primary sensory neurons

The research aimed to explore the biological role of p53 protein and long non-coding RNA (lncRNA) taurine upregulated gene 1 (TUG1) in bupivacaine (bup)-induced neurotoxicity. Our work treated dorsal root ganglion (DRG) cells with bup, detected cell viability through CCK-8, apoptosis through TUNEL assays, DeoxyriboNucleic Acid (DNA) damage through γ-H2AX protein and comet assay, including p53 mRNA, protein and TUG1 expression through q-PCR and western blot, furthermore, cell viability and DNA damage were determined after the silencing of p53 and TUG1, biological information and TUG1 FISH combined with p53 protein immunofluorescence (IF) was performed to determine the cellular localization of these molecule. In vivo experiments, we explored the impact of intrathecal injection of bup on p53 mRNA and protein, TUG1, γ-H2AX protein expression. The results showed that bup was available to signally decreased cell viability, promoted apoptosis rate and DNA damage, additionally, bup increased p53 mRNA and protein and TUG1 expression. P53 siRNA and TUG1 siRNA significantly increased DNA damage. Furthermore, bioinformatics analysis and colocalization experiments revealed that the p53 protein is a transcription factor of TUG1, in vivo experiment, intrathecal injection of bup increased the p53 mRNA, p53 protein, TUG1 and γ-H2AX protein in the murine DRG. In this study, it was found p53 and TUG1 promote the repair of the DNA damage induced by bup in murine dorsal root ganglion cells, suggesting a new strategy for the amelioration of bup-induced neurotoxicity.

Modulators of TRPM7 and its potential as a drug target for brain tumours

TRPM7 is a non-selective divalent cation channel with an alpha-kinase domain. Corresponding with its broad expression, TRPM7 has a role in a wide range of cell functions, including proliferation, migration, and survival. Growing evidence shows that TRPM7 is also aberrantly expressed in various cancers, including brain cancers. Because ion channels have widespread tissue distribution and result in extensive physiological consequences when dysfunctional, these proteins can be compelling drug targets. In fact, ion channels comprise the third-largest drug target type, following enzymes and receptors. Literature has shown that suppression of TRPM7 results in inhibition of migration, invasion, and proliferation in several human brain tumours. Therefore, TRPM7 presents a potential target for therapeutic brain tumour interventions. This article reviews current literature on TRPM7 as a potential drug target in the context of brain tumours and provides an overview of various selective and non-selective modulators of the channel relevant to pharmacology, oncology, and ion channel function.

Molecular insights on chemopreventive and anticancer potential of carvacrol: Implications from solid carcinomas

Globally, cancer is one of the deadliest diseases, estimated to cause 9.9 million deaths in 2020. Conventional cancer treatments commonly involve mono-chemotherapy or a combination of radiotherapy and mono-chemotherapy. However, the negative side effects of these approaches have been extensively reported and have prompted the search for new therapeutic drugs. Over the past few years, numerous dietary agents, medicinal plants, and their phytochemicals gained considerable therapeutic importance because of their anticancer, antiviral, anti-inflammatory, and antioxidant activities. Recent years have shown that essential oils possess therapeutic effects against numerous cancers. They are primarily used due to their lesser side effects than standard chemotherapeutic drugs. Carvacrol (CRV) is a phenolic monoterpenoid found in essential oils of oregano, thyme, pepperwort, wild bergamot, and other plants. Numerous anticancer reports of CRV substantiated that the main mechanistic action of CRV involves reduction in the viability of cancer cells and induction of apoptosis via both intrinsic and extrinsic pathways. CRV also obstructs the migration and invasion of cells leading to the suppressed proliferation rate. Furthermore, CRV mediates augmented ROS generation resulting in DNA damage and also halts the progression of cell cycle. Treatment of CRV modulates the expression of apoptotic proteins (Bax, Bad) and molecular targets of various signaling pathways (PI3K/AKT/mTOR, MAPKs, and Notch) in multiple solid carcinomas. Hence, this review aimed to acquire and disseminate the knowledge of chemopreventive and anticancer effects of CRV and the mechanisms of action already described for the compound against numerous cancers, including solid carcinomas, to guide future research. PRACTICAL APPLICATIONS: Development and formulation of phytocompound based anticancer drug agents to counteract the aftereffects of chemotherapeutic drugs is a propitious approach. CRV is a monoterpenoid consisting of a phenolic group obtained from the essential oils of oregano and thyme. These plants are being used as food flavoring spice and as fragrance ingredient in various cosmetic formulations. For the use of CRV as an efficient chemopreventive agent, different therapeutic interactions of CRV along with its targeted pathways and molecules, involved in the regulation of onset and progression of various types of solid carcinomas, need to be studied and explored thoroughly.

Anti-Inflammatory and Antioxidant Properties of Carvacrol and Magnolol, in Periodontal Disease and Diabetes Mellitus

Periodontal disease and diabetes mellitus are two pathologies that are extremely widespread worldwide and share the feature of chronic inflammation. Carvacrol is a phenolic monoterpenoid, produced by a variety of herbs, the most well-known of which is Origanum vulgare. Magnolol is a traditional polyphenolic compound isolated from the stem bark of Magnolia officinalis, mainly used in Chinese medicine. The purpose of this paper is to review the therapeutic properties of these bioactive compounds, in the treatment of periodontitis and diabetes. Based on our search strategy we conducted a literature search in the PubMed and Google Scholar databases to identify studies. A total of one hundred eighty-four papers were included in the current review. The results show that carvacrol and magnolol have anti-inflammatory, antioxidant, antimicrobial, anti-osteoclastic, and anti-diabetic properties that benefit both pathologies. Knowledge of the multiple activities of carvacrol and magnolol can assist with the development of new treatment strategies, and the design of clinical animal and human trials will maximize the potential benefits of these extracts in subjects suffering from periodontitis or diabetes.

Cytotoxic effects on cancerous and non-cancerous cells of trans-cinnamaldehyde, carvacrol, and eugenol

Essential oils and their active components, referred here as plant derived antimicrobials (PDAs), have been used for their antimicrobial, anti-inflammatory and antioxidant properties. Many reports also document PDAs' cytotoxic effects on cancerous cells, raising the hope that they could be used for cancer treatments. Due to the lack of specificity, we hypothesize that PDAs are cytotoxic to both cancerous and non-cancerous cells. Trans-cinnamaldehyde (TCA), carvacrol, and eugenol were assessed for their cytotoxicity on cancerous HeLa cells and normal skin fibroblasts (CCD-1123Sk, CCD) by MTT and LDH assays, flow cytometry, and reverse transcription quantitative PCR (RT-qPCR). After 24 h of treatment, carvacrol and TCA significantly decreased cell viability (by more than 50%) at 100 µg/ml, whereas eugenol was ineffective up to 400 µg/ml. Cell detachment and significantly increased apoptosis were observed with 100 µg/ml of TCA on both cell types. RT-qPCR for apoptotic genes (BCL2, CASP3 and CASP8) and necrosis genes (MLKL, RIPK1 and RIPK3) did not show significant differences between control and treated cells of both types, with the exception of eugenol-treated HeLa cells in which expression of BCL2, MLKL and RIPK1 was significantly higher than controls. Taken together, we conclude that the three PDAs studied here exhibited similar cytotoxic effects on both cancerous and non-cancerous cells.

Antitumor Effects of Carvacrol and Thymol: A Systematic Review

Background: It is estimated that one in five people worldwide faces a diagnosis of a malignant neoplasm during their lifetime. Carvacrol and its isomer, thymol, are natural compounds that act against several diseases, including cancer. Thus, this systematic review aimed to examine and synthesize the knowledge on the antitumor effects of carvacrol and thymol.

Methods: A systematic literature search was carried out in the PubMed, Web of Science, Scopus and Lilacs databases in April 2020 (updated in March 2021) based on the PRISMA 2020 guidelines. The following combination of health descriptors, MeSH terms and their synonyms were used: carvacrol, thymol, antitumor, antineoplastic, anticancer, cytotoxicity, apoptosis, cell proliferation, in vitro and in vivo. To assess the risk of bias in in vivo studies, the SYRCLE Risk of Bias tool was used, and for in vitro studies, a modified version was used.

Results: A total of 1,170 records were identified, with 77 meeting the established criteria. The studies were published between 2003 and 2021, with 69 being in vitro and 10 in vivo. Forty-three used carvacrol, 19 thymol, and 15 studies tested both monoterpenes. It was attested that carvacrol and thymol induced apoptosis, cytotoxicity, cell cycle arrest, antimetastatic activity, and also displayed different antiproliferative effects and inhibition of signaling pathways (MAPKs and PI3K/AKT/mTOR).

Conclusions: Carvacrol and thymol exhibited antitumor and antiproliferative activity through several signaling pathways. In vitro, carvacrol appears to be more potent than thymol. However, further in vivo studies with robust methodology are required to define a standard and safe dose, determine their toxic or side effects, and clarify its exact mechanisms of action.

This systematic review was registered in the PROSPERO database (CRD42020176736) and the protocol is available at https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=176736.

The effects of carvacrol on oxidative stress, inflammation, and liver function indicators in a systemic inflammation model induced by lipopolysaccharide in rats

The effect of carvacrol (CAR) on oxidative stress, inflammation, and liver dysfunction induced by lipopolysaccharide (LPS) was explored. The rats (n=40) were daily injected (2 weeks) by saline as control, LPS (1 mg/kg, i.p.), and 25, 50 or 100 mg/kg CAR (i.p.) before LPS. LPS increased aspartate transaminase (AST: 162±13 U/L), alanine aminotransferase (ALT: 74.6±2.15 U/L), alkaline phosphatase (ALK-P: 811±51 U/L), interlukine-1β (IL-1β: 1254±51 pg/g tissue), malondialdehyde (MDA: 32±1.09 nM/g tissue), and nitric oxide (NO: 224±13.5 nM/g tissue) (P<0.01-P<0.001) while, decreased total protein(4.08±0.38 g/dl), albumin(2.79±0.16 g/dl), thiol (5.16±0.19 μM/g tissue), superoxide dismutase (SOD: 10.57±0.13 U/g tissue), and catalase (CAT: 0.78±0.02 U/g tissue) compared to control (P<0.001). CAR reversed the effects of LPS (P<0.05-P<0.001). In the rats treated by 100 mg/kg CAR, the indicators were as follows: AST: 118±10.1 U/L, ALT: 42.5±4.13 U/L, ALK-P: 597±39.91 U/L, IL-1β: 494±15 pg/g tissue, and NO: 141±5.35 nM/g tissue. Both 50 and 100 mg/kg CAR corrected oxidative stress indicators and in the group treated by 100 mg/kg CAR, they were: MDA: 23.4±0.91 nM/g tissue, thiol: 7.98±0.18 μM/g tissue, SOD: 21±0.8 U/g tissue, and CAT: 1.12±0.02 U/g tissue(P<0.05-P<0.001). In conclusion, CAR improved liver function, accompanied with antioxidant and antiinflammatory effects.

Natural and synthetic antimicrobials reduce adherence of enteroaggregative and enterohemorrhagic Escherichia coli to epithelial cells

Adherence of bacteria to the human intestinal mucosa can facilitate their internalization and the development of pathological processes. Escherichia coli O104:H4 is considered a hybrid strain (enteroaggregative hemorrhagic E. coli [EAHEC]), sharing virulence factors found in enterohemorrhagic (EHEC), and enteroaggregative (EAEC) E. coli pathotypes. The objective of this study was to analyze the effects of natural and synthetic antimicrobials (carvacrol, oregano extract, brazilin, palo de Brasil extract, and rifaximin) on the adherence of EHEC O157:H7, EAEC 042, and EAHEC O104:H4 to HEp-2 cells and to assess the expression of various genes involved in this process. Two concentrations of each antimicrobial that did not affect (p≤0.05) bacterial viability or damage the bacterial membrane integrity were used. Assays were conducted to determine whether the antimicrobials alter adhesion by affecting bacteria and/or alter adhesion by affecting the HEp-2 cells, whether the antimicrobials could detach bacteria previously adhered to HEp-2 cells, and whether the antimicrobials could modify the adherence ability exhibited by the bacteria for several cycles of adhesion assays. Giemsa stain and qPCR were used to assess the adhesion pattern and gene expression, respectively. The results showed that the antimicrobials affected the adherence abilities of the bacteria, with carvacrol, oregano extract, and rifaximin reducing up to 65% (p≤0.05) of E. coli adhered to HEp-2 cells. Carvacrol (10 mg/ml) was the most active compound against EHAEC O104:H4, even altering its aggregative adhesion pattern. There were changes in the expression of adhesion-related genes (aggR, pic, aap, aggA, and eae) in the bacteria and oxidative stress-related genes (SOD1, SOD2, CAT, and GPx) in the HEp-2 cells. In general, we demonstrated that carvacrol, oregano extract, and rifaximin at sub-minimal bactericidal concentrations interfere with target sites in E. coli, reducing the adhesion efficiency.

Investigation of the potential anticancer effects of napelline and talatisamine dirterpenes on experimental brain tumor models

Brain cancers are one of the most aggressive tumours in humans. Especially, gliomas are among the deadliest of human cancers and show high resistance to chemotherapeutic agents. On the other hand, discovery of biologically effective non-synthetic biomaterials in treatments of different diseases, especially cancer, has continued to be one of the most popular research topics today. Therefore, we aimed to investigate biochemical, cytological and molecular genetic effects of napelline and talatisamine diterpenes in human U-87 MG glioma cells by using total antioxidant status and total oxidative status, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxphenyl)-2-(4-sulfophenyl)-2H-tetrozolium, inner salt and lactate dehydrogenase release assay and RT2 Prolifer PCR Arrays. Our results revealed that napelline and talatisamine exhibited cytotoxic effects at high doses. Napelline and talatisamine diterpenes increased apoptosis compared to control in U-87 MG cells. While napelline induced up-regulation of 50 and down-regulation of 13 genes, talatisamine induced up-regulation of 32 and down-regulation of 18 genes in U-87 MG cells. Napelline was shown to have a higher anticancer activity than talatisamine. We think that, napelline and talatisamine might be evaluated as potential chemotherapeutic agents for treatment of glioblastoma.

In vitro effects of two major phenolic compounds from the family Lamiaceae plants on the human gastric carcinoma cells

Phenolic compounds of essential oils from the family Lamiaceae are commonly used substances in the food industry because of their flavouring, antimicrobial and antioxidant properties. In this context, it has become important to have healthy and safe products for consumers who are exposed to these phenolic compounds. The present study was aimed to investigate the toxic effects of carvacrol, thymol and their mixture on human gastric carcinoma (AGS) cells. Cells were analyzed after 24 h of exposure to different concentrations of carvacrol, thymol and their mixture by the ATP cell viability, 2',7' dichlorodihydrofluorescein diacetate (H2DCF-DA), reducte glutatione/oxide glutathione ((GSH)/GSSG-Glo) and comet assays. Apoptosis induction was studied by acridine orange/ethidium bromide staining and western blotting. Carvacrol, thymol and their mixture induced cytotoxicity, genotoxicity, apoptosis, increased reactive oxygen species (ROS) and decreased GSH levels after 24 h of their exposure in a dose-dependent manner. A close negative relationship was found between cell viability and ROS generation. We examined dose-dependent cytotoxic effects of carvacrol, thymol and their mixture in human AGS cells. Increased intracellular ROS causes oxidative stress in cells. The results indicated that these compounds should be used carefully in the food industry.

Effects of carvacrol on human fibroblast (WS-1) and gastric adenocarcinoma (AGS) cells in vitro and on Wistar rats in vivo

Carvacrol is a natural phenolic compound found in essential oils of Lamiaceae species. In the present study, an attempt has been made to elucidate the mechanism behind the anti-cancer potential of carvacrol on human gastric adenocarcinomas (AGS) by comparing its effects on cancer cells AGS to those on normal human fibroblast (WS-1) cells, in vitro. Cytotoxicity, reactive oxygen species (ROS) generation, glutathione (GSH) levels, genotoxicity, and apoptotic effects of carvacrol (0-600 µM) were studied in both cell lines. Additionally, the effect of high dose carvacrol (100 mg/kg BW) on the oxidative status was investigated in vivo. For this purpose, carvacrol was administered orally to male Wistar rats over a period of 60 days. Rats were weighed regularly. At the end of the experiment, rats were euthanized. Blood and stomach tissues were collected for biochemical and pathological examinations. The in vitro results showed significant differences in cell viability of AGS compared to WS-1 cells exposed to carvacrol. Also the extent of ROS generation, GSH reduction and DNA damage differed significantly between the cell lines studied (P ≤ 0.001). The differences observed were statistically significant at all concentrations applied (P ≤ 0.001). The results found in AGS cells were mirrored in the pathohistological findings obtained from animals of the in vivo experimental group. Changes in body weight, and oxidative stress index for plasma and stomach tissues of animals in this group were found to differ statistically significant from those found in the control group of Wistar rats (P ≤ 0.001). The data obtained from our present study uncovered that carvacrol has the potential to cause toxic effects in both, AGS and WS-1 cells but more effectively in cancer cells than in normal cells. The carvacrol-mediated responses observed in the in vitro and in vivo experiments presented suggest a double-edged pro-oxidative effect. Via this mechanism carvacrol induced cytotoxicity, apoptosis, and DNA damage in a dose-dependent manner in both cancer and normal cells and these activities were higher in cancer cells than those of normal cells.

Effects of natural phenolic compound carvacrol on the human gastric adenocarcinoma (AGS) cells in vitro

Gastric cancer (GC) is the most common cause of morbidity and mortality because of cancer. Medicinal plants containing polyphenolic compounds have gained importance in anticancer treatment. In this context, carvacrol is a main component of many plants in the family Lamiaceae that are frequently used in folk medicine and a good candidate to investigate for GC treatment. The present study aimed to explore the cytotoxic, genotoxic, apoptotic, and reactive oxygen species (ROS)-generating effects of carvacrol on gastric adenocarcinoma in vitro. For these purposes, human gastric adenocarcinoma (AGS) cells were used and analyzed after 24 h of exposure to carvacrol with different concentrations. The cytotoxicity, ROS generation, glutathione (GSH) level, and genotoxicity were investigated by the ATP cell viability assay, 2',7'-dichlorodihydrofluorescein-diacetate assay, GSH/GSSG-Glo assay, and comet assay, respectively. Apoptosis induction was detected by acridine orange/ethidium bromide staining and western blotting at below the half-maximal growth inhibitory concentration value. Carvacrol showed cytotoxic, genotoxic, apoptotic, ROS generating, and GSH-reducing effects on AGS cells in a dose-dependent manner. There was a close negative relationship between cell viability and ROS level. Carvacrol inhibited the proliferation of AGS cells, suggesting that it could be a novel and strong anticancer agent against the human gastric adenocarcinoma. These results support the interest of natural diet components in the development of therapeutic products for diseases.

Genotoxicity evaluation of carvacrol in rats using a combined micronucleus and comet assay

Genotoxic data of substances which could be incorporated into food packaging are required by the European Food Safety Authority. Due to its antioxidant and antibacterial properties carvacrol is one of these compounds. This work aims to study for the first time the in vivo genotoxic effects produced in rats orally exposed to 81, 256 or 810 mg cavacrol/kg body weight (bw) at 0, 24 and 45 h. A combination of the micronucleus assay (OECD 474) in bone marrow and the standard (OECD 489) and enzyme-modified comet assay was used to determine the genotoxicity on cells isolated from stomach and liver of exposed animals. In addition, a histopathological study was performed on the assayed tissues, and also in the lungs due to the volatility of carvacrol. Direct analytical pyrolysis was used to search for carvacrol in viscera and to ensure that the compound reaches stomach and liver cells. Results from MN-comet assay revealed that carvacrol (81-810 mg/kg bw) did not induce in vivo genotoxicity or oxidative DNA damage in any of the tissues investigated. Moreover, no histopathological changes were observed. Altogether, these results suggest lack of genotoxicity of carvacrol and therefore its good profile for its potential application as food preservative.

Inhibition of TRPM7 by carvacrol suppresses glioblastoma cell proliferation, migration and invasion

Glioblastomas are progressive brain tumors with devastating proliferative and invasive characteristics. Ion channels are the second largest target class for drug development. In this study, we investigated the effects of the TRPM7 inhibitor carvacrol on the viability, resistance to apoptosis, migration, and invasiveness of the human U87 glioblastoma cell line.

The expression levels of TRPM7 mRNA and protein in U87 cells were detected by RT-PCR, western blotting and immunofluorescence. TRPM7 currents were recorded using whole-cell patch-clamp techniques. An MTT assay was used to assess cell viability and proliferation. Wound healing and transwell experiments were used to evaluate cell migration and invasion. Protein levels of p-Akt/t-Akt, p-ERK1/2/t-ERK1/2, cleaved caspase-3, MMP-2 and phosphorylated cofilin were also detected.

TRPM7 mRNA and protein expression in U87 cells is higher than in normal human astrocytes. Whole-cell patch-clamp recording showed that carvacrol blocks recombinant TRPM7 current in HEK293 cells and endogenous TRPM7-like current in U87 cells. Carvacrol treatment reduced the viability, migration and invasion of U87 cells. Carvacrol also decreased MMP-2 protein expression and promoted the phosphorylation of cofilin. Furthermore, carvacrol inhibited the Ras/MEK/MAPK and PI3K/Akt signaling pathways.

Therefore, carvacrol may have therapeutic potential for the treatment of glioblastomas through its inhibition of TRPM7 channels.

Preparation and in vitro investigation of antigastric cancer activities of carvacrol-loaded human serum albumin nanoparticles

In this study, carvacrol-loaded human serum albumin (HSA) nanoparticles were developed and characterised. Nanoparticles were prepared by desolvation and emulsion/desolvation methods. Encapsulation efficiency (EE%) and loading capacity (LC%) of nanoparticles prepared by desolvation method were 48.4 and 45.1%, respectively. Carvacrol-loaded nanoparticles had 132±42 nm in diameter with monomodal distribution. Carvacrol-loaded nanoparticles which is prepared by emulsion/desolvation method had EE% and LC% of 32 and 32.3%, respectively, and 230±38 nm in size. The release of carvacrol from nanoparticles was monitored in phosphate-buffered saline (pH=7.4), 100 rpm at 37°C for 10 days. About 21.4% of carvacrol was released after 3 h from nanoparticles that were prepared by desolvation method. In emulsion/desolvation method, 26.8% of total carvacrol was released during 3 h of incubation. Cytotoxicity effect of loaded carvacrol was assessed by 3-[4, 5 dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test on gastric cancer cells line (AGS). Cell line was exposed to the free carvacrol, unloaded and carvacrol-loaded nanoparticles for 48 h. The half maximal inhibitory concentration (IC50) for free carvacrol, unloaded and carvacrol-loaded HSA nanoparticles were 30, 1070 and 120 µg/ml, respectively. In conclusion, the results of this study showed applications of HSA nanoparticles for entrapment of carvacrol and antigastric cancer activity. Moreover, loading of carvacrol in combination with chemotherapy agents into the HSA nanoparticles may treat cancer cells better than single drug loaded nanoparticles.

Protective Effects of Carvacrol against Oxidative Stress Induced by Chronic Stress in Rat's Brain, Liver, and Kidney

Restraint stress may be associated with elevated free radicals, and thus, chronic exposure to oxidative stress may cause tissue damage. Several studies have reported that carvacrol (CAR) has a protective effect against oxidative stress. The present study was designed to investigate the protective effects of CAR on restraint stress induced oxidative stress damage in the brain, liver, and kidney. For chronic restraint stress, rats were kept in the restrainers for 6 h every day, for 21 consecutive days. The animals received systemic administrations of CAR daily for 21 days. To evaluate the changes of the oxidative stress parameters following restraint stress, the levels of malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and catalase (CAT) activities were measured in the brain, liver, and kidney. In the stressed animals that received vehicle, the MDA level was significantly higher (P < 0.001) and the levels of GSH and antioxidant enzymes were significantly lower than the nonstressed animals (P < 0.001). CAR ameliorated the changes in the stressed animals as compared with the control group (P < 0.001). This study indicates that CAR can prevent restraint stress induced oxidative damage.

The carvacrol ameliorates acute pancreatitis-induced liver injury via antioxidant response

Acute pancreatitis (AP) may cause significant persistent multi-organ dysfunction. Carvacrol (CAR) possesses a variety of biological and pharmacological properties. The aim of the present study was to analyze the hepatic protection of CAR on AP induced by cerulein and to explore the underlying mechanism using in vivo studies. The rats were randomized into groups to receive (1) no therapy; (2) 50 µg/kg cerulein at 1-h intervals by four intraperitoneal injection (i.p.); (3) 50, 100 and 200 mg/kg CAR by one i.p.; and (4) cerulein + CAR after 2 h of cerulein injection. 12 h later, serum was provided to assess the blood AST, ALT and LDH values. Also, liver tissues were obtained for histological and biochemical measurements. Liver oxidative stress markers were evaluated by changes in the amount of lipid peroxides measured as MDA and changes in tissue antioxidant enzyme levels, SOD, CAT and GSH-Px. Histopathological examination was performed using scoring systems. Oxidative damage to DNA was quantitated in studied tissues of experimental animals by measuring the increase in 8-hydroxydeoxyguanosine (8-OHdG) formations. We found that the increasing doses of CAR decreased pancreatitis-induced MDA and 8-OH-dG levels. Moreover, the liver SOD, CAT and GSH-Px activities in the AP + CAR group were higher than that of the rats in the AP group. In the treatment groups, AST, ALT and LDH were reduced. Besides, necrosis, coagulation and inflammation in the liver were alleviated (p < 0.05). We suggest that CAR could be a safe and potent new drug candidate for treating AP through its antioxidative mechanism of action for the treatment of a wide range of disorders related to hepatic dysfunction.

A Systematic Review of Iran’s Medicinal Plants With Anticancer Effects

Increase in cases of various cancers has encouraged the researchers to discover novel, more effective drugs from plant sources. This study is a review of medicinal plants in Iran with already investigated anticancer effects on various cell lines. Thirty-six medicinal plants alongside their products with anticancer effects as well as the most important plant compounds responsible for the plants’ anticancer effect were introduced. Phenolic and alkaloid compounds were demonstrated to have anticancer effects on various cancers in most studies. The plants and their active compounds exerted anticancer effects by removing free radicals and antioxidant effects, cell cycle arrest, induction of apoptosis, and inhibition of angiogenesis. The investigated plants in Iran contain the compounds that are able to contribute effectively to fighting cancer cells. Therefore, the extract and active compounds of the medicinal plants introduced in this review article could open a way to conduct clinical trials on cancer and greatly help researchers and pharmacists develop new anticancer drugs.

The in vitro protective effect of salicylic acid against paclitaxel and cisplatin-induced neurotoxicity

Paclitaxel (PAC) and cisplatin (CIS) are two established chemotherapeutic drugs used in combination for the treatment of various solid tumors. However, the usage of PAC and CIS are limited because of the incidence of their moderate or severe neurotoxic side effects. In this study, we aimed to assess the protective role of salicylic acid (SA) against neurotoxicity caused by PAC and CIS. For this purpose, newborn Sprague Dawley rats were decapitated in sterile atmosphere and primary cortex neuron cultures were established. On the 10th day SA was added into culture plates. PAC and CIS were added on the 12th day. The cytotoxicity was determined by using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Oxidative alterations were assessed using total antioxidant capacity and total oxidative stress assays in rat primary neuron cell cultures. It was shown that both concentrations of PAC and CIS treatments caused neurotoxicity. Although SA decreased the neurotoxicity by CIS and PAC, it was more effective against the toxicity caused by CIS rather than the toxicity caused by PAC. In conclusion it was clearly revealed that SA decreased the neurotoxic effect of CIS and PAC in vitro.

Carvacrol modulates oxidative stress and decreases cell injury in pancreas of rats with acute pancreatitis

Acute pancreatitis (AP) is considered as major problem around the world and the incidence of AP is increasing. Carvacrol (CAR), a monoterpenic phenol, has good antioxidant activity. This in vivo study was designed to evaluate whether CAR provide protection against AP that developed by pancreas injury. The rats were randomised into groups to receive (I) no therapy; (II) 50 µg/kg cerulein at 1 h intervals by four intraperitonally (i.p.) injections; (III) 50, 100 and 200 mg/kg CAR by one i.p. injection; and (IV) cerulein plus CAR after 2 h of cerulein administration. 12 h later, serum samples were obtained to assess pancreatic function, the lipase and amylase values. The oxidative stress markers were evaluated by changes in the amount of lipid peroxides measured as malondialdehyde (MDA) and changes in main tissue antioxidant enzyme levels including SOD, CAT and GSH-PX. Histopathological examination was performed using scoring systems. Additionally, oxidative DNA damage was determined by measuring the increases of 8-hydroxy-deoxyguanosine (8-OH-dG) formations. We found that the increasing doses of CAR decreased AP-induced MDA and 8-OH-dG levels. Moreover, the pancreas antioxidant enzyme activities were higher than that of the rats in the AP group when compared to the AP plus CAR group. In the treatment groups, the lipase and amylase were reduced. Besides, histopathological findings in the pancreatic tissue were alleviated (p < 0.05). We suggest that CAR could be a safe and potent new drug candidate for treating AP through its antioxidative mechanism of action for the treatment of a wide range of disorders related to pancreas.

Carvacrol exhibits anti-oxidant and anti-inflammatory effects against 1, 2-dimethyl hydrazine plus dextran sodium sulfate induced inflammation associated carcinogenicity in the colon of Fischer 344 rats

Chronic inflammation is one of the remarkable etiologic factors for various human ailments including cancer. The well known hypothesis is that persistent inflammation in colon can increase the risk of colorectal cancer (CRC). In this study, a pharmacological evaluation of carvacrol, a phenolic monoterpene constituent of essential oils produced from aromatic plant Oreganum vulgarea sp. on colitis associated colon cancer (CACC) induced by 1,2 Dimethylhydrazine (DMH) and dextran sodium sulfate (DSS) in male Fischer 344 rat model was studied. F344 rats were given three subcutaneous injections of DMH (40 mg/kg body wt) in the first week and were given free access to drinking water containing 1% DSS for the next one week followed by 7-14 days of water as three cycles. Carvacrol was administrated before and after tumor induction at a concentration of 50 mg/kg body weight (o.p). Carvacrol treated groups promotes the endogenous antioxidant system and suppress the inflammation in DMH/DSS induced animals. An increased antioxidant status and restoration of histological lesions in the inflamed colonic mucosa was observed in carvacrol treated rats. This effect was confirmed biochemically by reducing free-radical accumulation and suppressing expression of pro-inflammatory mediators. In this study, Carvacrol significantly increased the anti-oxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) glutathione (GSH) levels and reduced lipid peroxides (LPO), myeloperoxidase (MPO) and nitric oxide (NO) as compared to DMH/DSS induced rats. These dramatic changes facilitate the suppression of pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), and interleukin-1 beta (IL-1β) in CACC induced rats. Taken together, these findings suggest that Carvacrol may play a beneficial role in DMH/DSS induced experimental rat model and serve as an excellent dietary antioxidant as well as anti-inflammatory agent. It may represent novel therapeutic interventions against colon cancer triggered by chronic inflammation.

In vitro genotoxicity testing of carvacrol and thymol using the micronucleus and mouse lymphoma assays

Currently, antimicrobial additives derived from essential oils (Eos) extracted from plants or spices, such as Origanum vulgare, are used in food packaging. Thymol and carvacrol, the major EO compounds of O. vulgare, have demonstrated their potential use as active additives. These new applications use high concentrations, thereby increasing the concern regarding their toxicological profile and especially their genotoxic risk. The aim of this work was to investigate the potential in vitro genotoxicity of thymol (0-250 μM) and carvacrol (0-2500 μM) at equivalent doses to those used in food packaging. The micronucleus (MN) test and the mouse lymphoma (MLA) assay on L5178Y/Tk(±) mouse lymphoma cells were used. The negative results for thymol with the MN with and without the S9 fraction and also with the MLA assay reinforce the view that this compound is not genotoxic in mammalian cells. However, carvacrol presented slight genotoxic effects, but only in the MN test at the highest concentration assayed (700 μM) and in the absence of metabolic activation. The lack of genotoxic response in the MLA assay after 4 and 24h of exposure indicates a low genotoxic potential for carvacrol. Alternatively, the general negative findings observed in both assays suggest that the MN results of carvacrol are marginal data without biological relevance. These results can be useful to identify the appropriate concentrations of these substances to be used as additives in food packaging.

In vitro toxicological evaluation of essential oils and their main compounds used in active food packaging: A review

Essential oils (EOs) and their main constituent compounds have been extensively investigated due to their application in the food industry for improving the shelf life of perishable products. Although they are still not available for use in food packaging in the market in Europe, considerable research in this field has been carried out recently. The safety of these EOs should be guaranteed before being commercialized. The aim of this work was to review the scientific publications, with a primary focus on the last 10 years, with respect to different in vitro toxicological aspects, mainly focussed on mutagenicity/genotoxicity. In general, fewer genotoxic studies have been reported on EOs in comparison to their main components, and most of them did not show mutagenic activity. However, more studies are needed in this field since the guidelines of the European Food Safety Authority have not always been followed accurately. The mutagenic/genotoxic activities of these substances have been related to metabolic activation. Therefore, in vivo tests are required to confirm the absence of genotoxic effects. Considering the great variability of the EOs and their main compounds, a case-by-case evaluation is needed to assure their safe use in food packaging.

Chemistry and multibeneficial bioactivities of carvacrol (4-isopropyl-2-methylphenol), a component of essential oils produced by aromatic plants and spices

Aromatic plants produce organic compounds that may be involved in the defense of plants against phytopathogenic insects, bacteria, fungi, and viruses. One of these compounds, called carvacrol, which is found in high concentrations in essential oils such as oregano, has been reported to exhibit numerous bioactivities in cells and animals. This integrated overview surveys and interprets our present knowledge of the chemistry and analysis of carvacrol and its beneficial bioactivities. These activities include its antioxidative properties in food (e.g., lard, sunflower oil) and in vivo and the inhibition of foodborne and human antibiotic-susceptible and antibiotic-resistant pathogenic bacteria, viruses, pathogenic fungi and parasites, and insects in vitro and in human foods (e.g., apple juice, eggs, leafy greens, meat and poultry products, milk, oysters) and food animal feeds and wastes. Also covered are inhibitions of microbial and fungal toxin production and the anti-inflammatory, analgesic, antiarthritic, antiallergic, anticarcinogenic, antidiabetic, cardioprotective, gastroprotective, hepatoprotective, and neuroprotective properties of carvacrol as well as metabolic, synergistic, and mechanistic aspects. Areas for future research are also suggested. The collated information and suggested research might contribute to a better understanding of agronomical, biosynthetic, chemical, physiological, and cellular mechanisms of the described health-promoting effects of carvacrol, and facilitate and guide further studies needed to optimize the use of carvacrol as a multifunctional food in pure and encapsulated forms, in edible antimicrobial films, and in combination with plant-derived and medical antibiotics to help prevent or treat animal and human diseases.

Evaluation of the mutagenicity and genotoxic potential of carvacrol and thymol using the Ames Salmonella test and alkaline, Endo III- and FPG-modified comet assays with the human cell line Caco-2

Currently, direct antimicrobial and antioxidant additives derived from essential oils are used in food packaging and are perceived by consumers as low-health-risk compounds. In this study, we investigated the potential mutagenicity and genotoxicity of carvacrol and thymol, major compounds in several essential oils, using the Ames Salmonella test and the alkaline, Endo III- and formamidopyrimidine glycosylase (FPG)-modified comet assays, respectively. Thymol did not show any mutagenic activity at any concentration assayed (0-250 μM), whereas carvacrol exhibited mutagenic potential, displaying greater activity in presence of the metabolic fraction (29-460 μM). The genotoxic effects were evaluated in the human colon carcinoma cell line Caco-2, and the standard comet assay revealed that neither carvacrol (0-460 μM) nor thymol (0-250 μM) had any affects at 24 and 48 h. The FPG-modified comet assay showed that the highest concentration of carvacrol (460 μM) caused DNA damage, indicating damage to the purine bases. These results should be used to identify the appropriate concentrations of carvacrol and thymol as additives in food packaging. Moreover, further studies are necessary to explore the safety and/or the toxicity mechanisms of these compounds.

Cytotoxicity and genotoxicity of zingiberene on different neuron cell lines in vitro

The main objective of this study is to investigate the cytotoxic, genotoxic and antioxidant properties of zingiberene (ZBN) in an in vitro rat brain cell culture study. The cytotoxic effect was determined against the rat neuron and N2a neuroblastoma (N2a-NB) cell lines using the 3,(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while the antioxidant activity was assessed using the total antioxidant capacity (TAC) and total oxidative stress (TOS) assays. The effects on DNA damage were also evaluated in this study by the single cell gel electrophoresis assay. The results indicated that ZBN has an anti-proliferative activity suppressing the proliferation of N2a-NB cells at concentrations over 50 mg L(-1) and neuron cells at concentrations over 150 mg L(-1). In addition, ZBN treatments at higher doses (≤50 mg L(-1)) led to increases of TOS levels in N2a-NB cell cultures. However 25 mg L(-1) of ZBN treatment caused increases of TAC levels in cultured neuron and N2a-NB cell cultures while ZBN at doses of 10-400 mg L(-1) did not increase the number of total damage score in both cell lines. This study clearly indicates that ZBN has a significant potential to be used as a natural anticancer agent in cultured N2a-NBs.

Genotoxic and oxidative damage potentials in human lymphocytes after exposure to terpinolene in vitro

Terpinolene (TPO) is a monocyclic monoterpene found in the essential oils of various fir and pine species. Recent reports indicated that several monoterpenes could exhibit antioxidant effects in both human and animal experimental models. However, so far, the nature and/or biological roles of TPO have not been elucidated in human models yet. The aim of this study was to investigate the genetic, oxidative and cytotoxic effects of TPO in cultured human blood cells (n = 5) for the first time. Human blood cells were treated with TPO (0-200 mg/L) for 24 and 48 h, and then cytotoxicity was detected by lactate dehydrogenase (LDH) release and [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay, while DNA damage was also analyzed by micronucleus assay, sister chromatid exchanges assay and 8-oxo-2-deoxyguanosine (8-OH-dG) level. In addition, biochemical parameters [total antioxidant capacity (TAC) and total oxidative stress (TOS)] were examined to determine oxidative effects. The results of LDH and MTT assays showed that TPO (at concentrations greater than 100 mg/L) decreased cell viability. In our in vitro test systems, it was observed that TPO had no genotoxicity on human lymphocytes. Again, TPO (at 10, 25, 50 and 75 mg/L) treatment caused statistically important (p < 0.05) increases of TAC levels in human lymphocytes without changing TOS levels. In conclusion, TPO can be a new resource of therapeutics as recognized in this study with its non-genotoxic and antioxidant features.

The effects of oral carvacrol treatment against H2O2 induced injury on isolated pancreas islet cells of rats

Pancreatic islet transplantation is an alternative treatment of insulin replacement therapy in diabetes mellitus, but the islets are exposed to many chemical, mechanical damages, and oxidative stress before transplantation. Carvacrol is a well-known essential oil for its antioxidant, antimicrobial, antifungal and antiinflammatory properties. The aim of this study was to investigate the possible protective effects of carvacrol against H 2O 2 induced cellular injury on isolated pancreas islets. After carvacrol (20, 40 and 80 mg/kg/day) treatment, the pancreas islets were isolated by enzyme digestion. The isolated islets were incubated within 0, 150 and 300 µM H 2O 2 containing medium at +4°C for 15 min. Then, the islets were examined with fluorescein diacetate and propidium iodide mixture stains for viability. A number of islets were stored for lipid peroxidation, protein oxidation and DNA fragmentation analysis. The cell viability ratio of Carvacrol 20 mg/kg/day group was increased in comparison to control and vehicle (DMSO) groups. Additionally, carvacrol application protected the cells from lipid peroxidation and protein oxidation induced by H 2O 2. H 2O 2 caused tissue injury and DNA fragmentation. There was only one DNA fragmentation band from islet cells of 20 mg/kg/day carvacrol treated group, however there were more than one bands from control and DMSO groups. In conclusion, carvacrol treatment ameliorates islet cell injury induced by H 2O 2. However, the dose of carvacrol is important and our results suggest that 20 mg/kg/day dose is more effective than doses of 40 or 80 mg/kg/day.