1,8-cineole protects against liver failure in an in-vivo murine model of endotoxemic shock

Andrographolide ameliorates sepsis-induced acute liver injury by attenuating endoplasmic reticulum stress through the FKBP1A-mediated NOTCH1/AK2 pathway

Andrographolide (AP) has been shown to possess anti-inflammatory activities. In this study, the impact of AP in sepsis-induced acute liver injury (ALI) and the molecules involved were dissected. FKBP1A was predicted to be the sole target protein of AP that was also differentially expressed in the GSE166868 dataset. AP induced the protein expression of FKBP1A and suppressed that of NOTCH1 in a dose-dependent manner. AP ameliorated ALI in mice induced by D-galactosamine and LPS and inhibited LPS-induced liver parenchymal cell injury in vitro. By contrast, the protective effect of AP was significantly lost after the knockdown of FKBP1A. As a positive control, the therapeutic effect of dexamethasone on ALI may be related to NOTCH1, which was not related to FKBP1A. NOTCH1 promoted AK2 transcription in liver parenchymal cells, and FKBP1A inhibited endoplasmic reticulum (ER) stress by impairing NOTCH1/AK2 signaling. Restoration of NOTCH1 significantly reversed the hepatoprotective effect of AP in ALI mice and LPS-induced liver parenchymal cell injury by activating the ER stress pathway. Therefore, AP-promoted FKBP1A expression inhibits ALI progression by blocking the NOTCH1/AK2-mediated ER pathway.

Modes of Action of 1,8-Cineol in Infections and Inflammation

The monoterpene 1,8-Cineol is a natural plant-based therapeutic agent that is commonly applied to treat different inflammatory diseases due to its mucolytic, anti-microbial and anti-inflammatory properties. It has become increasingly clear in the recent years that 1,8-Cineol spreads almost everywhere in the human body after its oral administration, from the gut to the blood to the brain. Its anti-microbial potential and even its anti-viral effects have been observed to include numerous bacteria and fungi species. Many recent studies help to better understand the cellular and molecular immunological consequences of 1,8-Cineol treatment in inflammatory diseases and further provide information concerning the mechanistic modes of action in the regulation of distinct inflammatory biosynthetic pathways. This review aims to present a holistic and understandable overview of the different aspects of 1,8-Cineol in infections and inflammation.

Eucalyptol antagonized the apoptosis and immune dysfunction of grass carp hepatocytes induced by tetrabromobisphenol A by regulating ROS/ASK1/JNK pathway

Tetrabromobisphenol A (TBBPA) is a common environmental pollutant which has multi-organ toxicity to mammals. Eucalyptol (EUC) has super antioxidant biological activity. However, in this experimental study, we probed into the mechanism of toxic of TBBPA exposure on Grass carp hepatocytes (L8824 cells) and the antagonistic impact of EUC on TBBPA. We treated L8824 cells with 8 μg/ml TBBPA and/or 20 μM EUC for 24 h in this test research. The experiment results suggested that TBBPA exposure induced elevated levels of reactive oxygen species (ROS), led to oxidative stress, decreased SOD and CAT activities, decreased GSH and T-AOC contents, exacerbated MDA accumulation, activated ASK1/JNK signaling pathway, and further increased the contents of mitochondrial dependent apoptosis pathway related indicators (Cyt-C, Bax, Caspase 9, Caspase 3), while Bcl-2 expression decreased. In addition, TBBPA exposure induced increased expression of TNF-α, IL-6, IL-1β, and decreased expression of IL-2, IFN-γ, Hepcidin, β-defensin, LEAP2. The oxidative stress level, ASK1/JNK signal pathway expression level, apoptosis ratio and cellular immune function of cells exposed to EUC alone did not change significantly. Combined exposure of TBBPA and EUC significantly reduced the proportion of apoptosis and restored cellular immune function. Therefore, these results suggest that EUC can effectively antagonize TBBPA-induced apoptosis and immune dysfunction of L8824 cells by regulating ROS/ASK1/JNK signaling pathway.

Essential Oils as Multicomponent Mixtures and Their Potential for Human Health and Well-Being

Essential oils (EOs) and their individual volatile organic constituents have been an inherent part of our civilization for thousands of years. They are widely used as fragrances in perfumes and cosmetics and contribute to a healthy diet, but also act as active ingredients of pharmaceutical products. Their antibacterial, antiviral, and anti-inflammatory properties have qualified EOs early on for both, the causal and symptomatic therapy of a number of diseases, but also for prevention. Obtained from natural, mostly plant materials, EOs constitute a typical example of a multicomponent mixture (more than one constituent substances, MOCS) with up to several hundreds of individual compounds, which in a sophisticated composition make up the property of a particular complete EO. The integrative use of EOs as MOCS will play a major role in human and veterinary medicine now and in the future and is already widely used in some cases, e.g., in aromatherapy for the treatment of psychosomatic complaints, for inhalation in the treatment of respiratory diseases, or topically administered to manage adverse skin diseases. The diversity of molecules with different functionalities exhibits a broad range of multiple physical and chemical properties, which are the base of their multi-target activity as opposed to single isolated compounds. Whether and how such a broad-spectrum effect is reflected in natural mixtures and which kind of pharmacological potential they provide will be considered in the context of ONE Health in more detail in this review.

Cineole alleviates the BPA-inhibited NETs formation by regulating the p38 pathway-mediated programmed cell death

Bisphenol A (BPA) is an endocrine disruptor, that can cause immune dysfunction. Cineole (CIN) has that effect of regulating immune function and resist oxidation. Neutrophil extracellular traps (NETs) are one of the ways to resist pathogen invasion. In order to explore the effects of BPA and CIN on the release of chicken NETs and the antagonistic effect of CIN, take chicken peripheral blood neutrophils as object of study, grouping as NC, CIN, BPA + CIN and BPA. SEM, flow cytometry, RT-PCR, Western-blot and other methods were used to detect related indicators. The results showed that BPA inhibited the activities of GPX, SOD and CAT, increased the contents of MDA and NO, increased the activity of iNOS. BPA exposure inhibited the expression of myeloperoxidase (MPO), neutrophil elastase (NE) and histone, and inhibited the release of NETs. BPA activated downstream apoptosis and necroptosis through the p38 mitogen-activated protein kinase (p38-MAPK) pathway, which increased the expression of cytochrome C (CytC), bcl-2 associated K protein gene (bak), cysteinyl aspartate specific proteinase 3 (caspase-3), cysteinyl aspartate specific proteinase 9 (caspase-9), receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 1 (RIPK3) and mixed lineage kinase domain-like protein (MLKL), decreased the expression of B-cell lymphoma-2 (bcl-2). However, the co-exposure of CIN and BPA partially recovered the release of NETs, alleviated BPA-induced oxidative stress, and inhibited the activation of p38-MAPK pathway, necroptosis, and mitochondrial apoptosis pathway. These results indicated that CIN modulated p38 pathway alleviated BPA-induced neutrophil necroptosis and apoptosis, and increased NETs formation.

Physicochemical characterization, cytotoxic effect and toxicity evaluation of nanostructured lipid carrier loaded with eucalyptol

Background

Eucalyptol is an active compound of eucalyptus essential oil and was reported to have many medical attributes including cytotoxic effect on breast cancer cells. However, it has low solubility in aqueous solutions which limits its bioavailability and cytotoxic efficiency. In this study, nanostructured lipid carrier loaded with eucalyptol (NLC-Eu) was formulated and characterized and the cytotoxic effect of NLC-Eu towards breast cancer cell lines was determined. In addition, its toxicity in animal model, BALB/c mice was also incorporated into this study to validate the safety of NLC-Eu.

Methods

Eucalyptol, a monoterpene oxide active, was used to formulate the NLC-Eu by using high pressure homogenization technique. The physicochemical characterization of NLC-Eu was performed to assess its morphology, particle size, polydispersity index, and zeta potential. The in vitro cytotoxic effects of this encapsulated eucalyptol on human (MDA MB-231) and murine (4 T1) breast cancer cell lines were determined using the MTT assay. Additionally, acridine orange/propidium iodide assay was conducted on the NLC-Eu treated MDA MB-231 cells. The in vivo sub-chronic toxicity of the prepared NLC-Eu was investigated using an in vivo BALB/c mice model.

Results

As a result, the light, translucent, milky-colored NLC-Eu showed particle size of 71.800 ± 2.144 nm, poly-dispersity index of 0.258 ± 0.003, and zeta potential of − 2.927 ± 0.163 mV. Furthermore, the TEM results of NLC-Eu displayed irregular round to spherical morphology with narrow size distribution and relatively uniformed particles. The drug loading capacity and entrapment efficiency of NLC-Eu were 4.99 and 90.93%, respectively. Furthermore, NLC-Eu exhibited cytotoxic effects on both, human and mice, breast cancer cells with IC50 values of 10.00 ± 4.81 μg/mL and 17.70 ± 0.57 μg/mL, respectively at 72 h. NLC-Eu also induced apoptosis on the MDA MB-231 cells. In the sub-chronic toxicity study, all of the studied mice did not show any signs of toxicity, abnormality or mortality. Besides that, no significant changes were observed in the body weight, internal organ index, hepatic and renal histopathology, serum biochemistry, nitric oxide and malondialdehyde contents.

Conclusions

This study suggests that the well-characterized NLC-Eu offers a safe and promising carrier system which has cytotoxic effect on breast cancer cell lines.

1,8-Cineole: a review of source, biological activities, and application

1,8-Cineole (also known as eucalyptol) is mostly extracted from the essential oils of plants, which showed extensively pharmacological properties including anti-inflammatory and antioxidant mainly via the regulation on NF-κB and Nrf2, and was used for the treatment of respiratory diseases and cardiovascular, etc. Although various administration routes have been used in the application of 1.8-cineole, few formulations have been developed to improve its stability and bioavailability. This review retrospects the researches on the source, biological activities, mechanisms, and application of 1,8-cineole since 2000, which provides a view for the further studies on the application and formulations of 1,8-cineole.

Biochemical Research of the Effects of Essential Oil Obtained from the Fruit of Myrtus communis L. on Cell Damage Associated with Lipopolysaccharide-Induced Endotoxemia in a Human Umbilical Cord Vein Endothelial Cells

The aim of this study to investigate the potential effects of essential oils and compounds obtained from MC fruit on sepsis induced endothelial cell damage in human umbilical cord vein endothelial cells (HUVECs) at molecular and cellular levels on in vitro sepsis model. A sepsis model was induced by the application of LPS. The HUVEC treatment groups were as follows: control, LPS, MC, MC plus LPS, 1.8 cineole, 1.8 cineole plus LPS, α-pinene, α-pinene plus LPS, α-terpineol, and α-terpineol plus LPS. Following the treatments, cell proliferation was analyzed using the xCELLigence® system. The mRNA expression of various cytokines [tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), and IL-6] and endothelial nitric oxide (eNOS) were determined by quantitative polymerase chain reaction (qPCR) analysis. The 1.8 cineole and α-pinene treatments at specific doses showed toxic effects on α-terpineine, although it did not result in a change in the cellular index as compared with that of the control group. The application of LPS to HUVECs led to a significant decrease in the cellular index, depending on the treatment time. It did not correct the decreased cell index of MC plus LPS and α-terpineol plus LPS groups as compared with that of the LPS-only group. The 1.8 cineole plus LPS treatment and α-pinene plus LPS treatment significantly increased the cell index as compared with that of the LPS-only treatment, and the cell index in these groups was closer to that of the control. According to the results of the qPCR analysis, neither the MC-only treatment nor the α-terpineol-only treatment significantly reduced cellular damage caused by LPS-induced increases in TNF-α, IL-1β, IL-6, and eNOS mRNA expression. However, both the 1.8 cineole treatment and α-pinene treatments significantly decreased TNF-α, IL-1β, IL-6, and eNOS mRNA expression induced by LPS. Volatile oil obtained from MC fruit and the MC compound α-terpineol had no effect on the decreased cell index and increased cytokine response due to LPS-induced endothelial cell damage. However, 1.8 cineole and α-pinene, other major components of MC fruit, ameliorated LPS-induced damage in HUVECs at cellular and biomolecular levels (TNF-α, IL-1β, IL-6, and eNOS).

Ethanol extract of Nigella sativa has antioxidant and ameliorative effect against nickel chloride-induced hepato-renal injury in rats

Background

Nickel exposure causes hepato-renal toxicity via oxidative stress. Medicinal plants with antioxidants properties are being explored as treatment options. In this study, the effect of ethanol extract of Nigella sativa (ENS) on nickel chloride (NiCl2)-induced hepato-renal damage was evaluated by monitoring biochemical and oxidative stress markers. Additionally, the antioxidant capacity and phytochemical constituents of ENS were quantified using HPLC and GC-MS.

Result

NiCl2 significantly increased (p < 0.05) aspartate aminotransferase, creatinine, sodium ion, chloride ion and malondialdehyde levels, while antioxidant enzymes were decreased in the organs except for kidney glutathione-S-transferase when compared to the control. However, ENS exerted inhibitory effect against NiCl2 toxicity in both organs by reversing the biomarkers towards control levels. ENS has a high antioxidant capacity and is rich in antioxidants including gallic acid, quercetin, eucalyptol and levomenthol that may have accounted for the improvement of hepato-renal health in co-exposed rats.

Conclusion

Our result suggests that amelioration of nickel chloride-induced hepato-renal pathology by ethanol extract of Nigella sativa was related to its antioxidant properties. Therefore, Nigella sativa could be valuable in the management of nickel-induced toxicity.

Volatiles Profile of the Floral Organs of a New Hybrid Cymbidium, 'Sunny Bell' Using Headspace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry Analysis

Cymbidium is one of the most important genera of flowering plants in the Orchidaceae family, and comprises a wide variety of beautiful and colorful species. Among these, only a few species possess floral scents and flavors. In order to increase the availability of a new Cymbidum hybrid, “Sunny Bell”, this study investigated the volatile floral scents. Volatiles of the floral organs of the new Cymbidium hybrid, “Sunny Bell”, at the full-flowering stage were characterized with headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis. A divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) fiber gave the best extraction for volatile components. Twenty-three components were identified as the main volatiles for the floral organs of the new Cymbidium hybrid, “Sunny Bell” at the full-flowering stage; twelve compounds in the column, sixteen compounds in the labellum, eleven compounds in the sepals, and nine compounds in the petals were identified. Terpenes are the major source of floral scents in this plant. As a result of GC-MS analysis, the most abundant compound was linalool (69–80%) followed by α-pinene (3–27%), 4,8-dimethyl-1,3,7-nonatriene (5–18%), eucalyptol (6–16%), and 2,6-dimethylnonane (2–16%). The main components were identified as monoterpenes in the petals and sepals, and as monoterpenes and aliphatics in the column and labellum. The results of this study provide a basis for breeding Cymbidium cultivars which exhibit desirable floral scents.

Microencapsulation of eucalyptol in polyethylene glycol and polycaprolactone using particles from gas-saturated solutions

Eucalyptol is the natural cyclic ether which constitutes the bulk of terpenoids found in essential oils of Eucalyptus spp. and is used in aromatherapy for treatment of migraine, sinusitis, asthma and stress. It acts by inhibiting arachidonic acid metabolism and cytokine production. Chemical instability and volatility of eucalyptol restrict its therapeutic application and necessitate the need to develop an appropriate delivery system to achieve extended release and enhance its bioactivity. However, the synthesis method of the delivery system must be suitable to prevent loss or inactivation of the drug during processing. In this study, supercritical carbon dioxide (scCO₂) was explored as an alternative solvent for encapsulation and co-precipitation of eucalyptol with polyethylene glycol (PEG) and/or polycaprolactone (PCL) using the particles from gas-saturated solution (PGSS) process. Polymers and eucalyptol were pre-mixed and then processed in a PGSS autoclave at 45 °C and 80 bar for 1 h. The mixture in scCO₂ was micronized and characterized. The presence of eucalyptol in the precipitated particles was confirmed by infrared spectroscopy, gas chromatography and mass spectrometry. The weight ratios of PEG–PCL blends significantly influenced loading capacity and encapsulation efficiency with 77% of eucalyptol encapsulated in a 4 : 1 composite blend of PEG–PCL. The particle size distribution of the PGSS-micronized particles ranged from 30 to 260 μm. ScCO₂ assisted microencapsulation in PEG and PCL reduced loss of the volatile drug during a two-hour vaporization study and addition of PCL extended the mean release time in simulated physiological fluids. Free radical scavenging and lipoxygenase inhibitory activities of eucalyptol formulated in the PGSS-micronized particles was sustained. Findings from this study showed that the scCO₂-assisted micronization can be used for encapsulation of volatile drugs in polymeric microparticles without affecting bioactivity of the drug.

Application of supercritical carbon dioxide as an alternative solvent for microformulation of the volatile unstable drug, eucalyptol in polymeric composites.

Systems pharmacology-based investigation of Sanwei Ganjiang Prescription: related mechanisms in liver injury

Liver injury remains a significant global health problem and has a variety of causes, including oxidative stress (OS), inflammation, and apoptosis of liver cells. There is currently no curative therapy for this disorder. Sanwei Ganjiang Prescription (SWGJP), derived from traditional Chinese medicine (TCM), has shown its effectiveness in long-term liver damage therapy, although the underlying molecular mechanisms are still not fully understood. To explore the underlining mechanisms of action for SWGJP in liver injury from a holistic view, in the present study, a systems pharmacology approach was developed, which involved drug target identification and multilevel data integration analysis. Using a comprehensive systems approach, we identified 43 candidate compounds in SWGJP and 408 corresponding potential targets. We further deciphered the mechanisms of SWGJP in treating liver injury, including compound-target network analysis, target-function network analysis, and integrated pathways analysis. We deduced that SWGJP may protect hepatocytes through several functional modules involved in liver injury integrated-pathway, such as Nrf2-dependent anti-oxidative stress module. Notably, systems pharmacology provides an alternative way to investigate the complex action mode of TCM.

Monoterpenes modulating cytokines - A review

Inflammatory response can be driven by cytokine production and is a pivotal target in the management of inflammatory diseases. Monoterpenes have shown that promising profile as agents which reduce the inflammatory process and also modulate the key chemical mediators of inflammation, such as pro and anti-inflammatory cytokines. The main interest focused on monoterpenes were to develop the analgesic and anti-inflammatory drugs. In this review, we summarized current knowledge on monoterpenes that produce anti-inflammatory effects by modulating the release of cytokines, as well as suggesting that which monoterpenoid molecules may be most effective in the treatment of inflammatory disease. Several different inflammatory markers were evaluated as a target of monoterpenes. The proinflammatory and anti-inflammatory cytokines were found TNF-α, IL-1β, IL-2, IL-5, IL-4, IL-6, IL-8, IL-10, IL-12 IL-13, IL-17A, IFNγ, TGF-β1 and IFN-γ. Our review found evidence that NF-κB and MAPK signaling are important pathways for the anti-inflammatory action of monoterpenes. We found 24 monoterpenes that modulate the production of cytokines, which appears to be the major pharmacological mechanism these compounds possess in relation to the attenuation of inflammatory response. Despite the compelling evidence supporting the anti-inflammatory effect of monoterpenes, further studies are necessary to fully explore their potential as anti-inflammatory compounds.

1,8-cineol inhibits the Wnt/β-catenin signaling pathway through GSK-3 dephosphorylation in nasal polyps of chronic rhinosinusitis patients

Chronic rhinosinusitis with nasal polyps (CRSwNP) represents a benign neoplasm of the nasal mucosa, which leads to a decreased breathing capacity and reduced olfaction. The pathogenesis and the molecular mechanisms driving nasal polyps are not very well known. GSK-3 is involved in the regulation of various biosynthetic pathways and various kinases are able to regulate the GSK-3. Therefore, we investigated the effect of the monoterpene oxide 1,8-cineol on the regulation of the Wnt/β-catenin signaling pathway with its central regulator protein GSK-3 in vitro. We determined GSK-3 expression and phosphorylation as well as the expression of negative regulators (Akt and SGK) and downstream activation of β-catenin in nasal polyps of patients with CRSwNP by immunohistochemistry and Western blot experiments. In this study we demonstrated for the first time, that 1,8-cineol acts as a potential inhibitor of the Wnt/β-catenin signaling pathway, by affecting the inhibitory phosphorylation of GSK-3, which is the key regulator of the β-catenin activity. Our data provide novel insights in the regulatory networks responsible for the progression of CRSwNP and furthermore represent a new mechanism of 1,8-cineol activity, which may lead to novel treatment approaches to this natural drug.

Chronic diseases, inflammation, and spices: how are they linked?

Extensive research within the last several decades has revealed that the major risk factors for most chronic diseases are infections, obesity, alcohol, tobacco, radiation, environmental pollutants, and diet. It is now well established that these factors induce chronic diseases through induction of inflammation. However, inflammation could be either acute or chronic. Acute inflammation persists for a short duration and is the host defense against infections and allergens, whereas the chronic inflammation persists for a long time and leads to many chronic diseases including cancer, cardiovascular diseases, neurodegenerative diseases, respiratory diseases, etc. Numerous lines of evidence suggest that the aforementioned risk factors induced cancer through chronic inflammation. First, transcription factors NF-κB and STAT3 that regulate expression of inflammatory gene products, have been found to be constitutively active in most cancers; second, chronic inflammation such as pancreatitis, prostatitis, hepatitis etc. leads to cancers; third, activation of NF-κB and STAT3 leads to cancer cell proliferation, survival, invasion, angiogenesis and metastasis; fourth, activation of NF-κB and STAT3 leads to resistance to chemotherapy and radiation, and hypoxia and acidic conditions activate these transcription factors. Therefore, targeting these pathways may provide opportunities for both prevention and treatment of cancer and other chronic diseases. We will discuss in this review the potential of various dietary agents such as spices and its components in the suppression of inflammatory pathways and their roles in the prevention and therapy of cancer and other chronic diseases. In fact, epidemiological studies do indicate that cancer incidence in countries such as India where spices are consumed daily is much lower (94/100,000) than those where spices are not consumed such as United States (318/100,000), suggesting the potential role of spices in cancer prevention.

Health Benefits of Fennel, Rosemary Volatile Oils and their Nano-Forms in Dyslipidemic Rat Model

BACKGROUND AND OBJECTIVE

Dyslipidemia is a major health problem that may lead to cardiovascular diseases (CVDs). In the present research, a biological experiment was run on dyslipidemic rats to study the health benefits of the volatile oils (VOs) of fennel and rosemary in its original and nano-form using chitosan as carrier.

MATERIALS AND METHODS

Rats were divided into 6 groups; normal control, dyslipidemic control and 4 test groups with dyslipidemia and treated by VOs of fennel and rosemary and their respective nano-forms separately. Glucose tolerance test was carried out after 4 weeks. Parameters reflecting oxidative stress/antioxidant plasma catalase, malondialdehyde (MDA) and blood uric acid, were assessed. Plasma lipid profile and tumor necrosis factor alpha (TNF-α) as inflammatory biomarker were determined. Liver and kidney function were assessed as determinant of the safety of the different VO forms. Twenty four hour urinary volume was measured to assess creatinine clearance and to evaluate the possible diuretic activity of the VOs.

RESULTS

Dyslipidemic control rats showed dyslipidemia, increased CVDs risk, liver dysfunction, elevated MDA and TNF-α with marked increase in blood sugar after half an hour of glucose ingestion compared to normal control. Treatment with the four VOs forms improved the majority of the biochemical parameters.

CONCLUSION

All treatment showed cardio and hepato- protective effect and safety towards kidney and blood sugar. Oxidative stress and inflammatory biomarkers were significantly improved by the different treatments; both VO forms of fennel were more efficient in ameliorating inflammation.

Melaleuca quinquenervia essential oil inhibits α-melanocyte-stimulating hormone-induced melanin production and oxidative stress in B16 melanoma cells

BACKGROUND

Essential oils are odorous, volatile products of plant secondary metabolism, which are found in many leaves and stems. They show important biological activities, which account for the development of aromatherapy used in complementary and alternative medicine. The essential oil extracted from Melaleuca quinquenervia (Cav.) S.T. Blake (paperbark) (MQ-EO) has various functional properties.

PURPOSE

The aim of this study is to investigate the chemical composition of MQ-EO by using gas chromatography-mass spectrometry (GC-MS) and evaluate its tyrosinase inhibitory activity.

METHODS

Gas chromatography-mass spectrometry (GC-MS)-based metabolomics was used to identify 18 components in MQ-EO. The main components identified were 1,8-cineole (21.60%), α-pinene (15.93%), viridiflorol (14.55%), and α-terpineol (13.73%). B16 melanoma cells were treated with α-melanocyte-stimulating hormone (α-MSH) in the presence of various concentrations of MQ-EO or its major compounds. Cell viability was accessed by MTT assay and cellular tyrosinase activity and melanin content were determined by using spectrophotographic methods. The antioxidant mechanism of MQ-EO in α-MSH stimulated B16 cells was also investigated.

RESULTS

In α-melanocyte-stimulating hormone (α-MSH)-stimulated murine B16 melanoma cells, MQ-EO, 1,8-cineole, α-pinene, and α-terpineol significantly reduced melanin content and tyrosinase activity. Moreover, MQ-EO, 1,8-cineole, α-pinene, and α-terpineol decreased malondialdehyde (MDA) levels. In addition, restored glutathione (GSH) levels, glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase activities were increased in α-MSH-stimulated B16 cells. MQ-EO not only decreased apoptosis but also reduced DNA damage in α-MSH stimulated B16 cells. These results showed that MQ-EO and its main components, 1,8-cineole, α-pinene, and α-terpineol, possessed potent anti-tyrosinase and anti-melanogenic activities besides the antioxidant properties.

CONCLUSIONS

The active functional components of MQ-EO were found to be 1,8-cineole, α-pinene, and α-terpineol. Consequently, the results of present study suggest that MQ-EO is non-cytotoxic and can be used as a skin-whitening agent, both medically and cosmetically.

Transient Receptor Potential Cation Channel Subfamily M Member 8 channels mediate the anti-inflammatory effects of eucalyptol

BACKGROUND AND PURPOSE

Eucalyptol (1,8-cineol), the major ingredient in the essential oil of eucalyptus leaves and other medicinal plants, has long been known for its anti-inflammatory properties. Eucalyptol interacts with the TRP cation channels among other targets, but it is unclear which of these mediates its anti-inflammatory effects.

EXPERIMENTAL APPROACH

Effects of eucalyptol were compared in wild-type and TRPM8 channel-deficient mice in two different models: footpad inflammation elicited by complete Freund's adjuvant (CFA) and pulmonary inflammation following administration of LPS. Oedema formation, behavioural inflammatory pain responses, leukocyte infiltration, enzyme activities and cytokine and chemokine levels were measured.

KEY RESULTS

In the CFA model, eucalyptol strongly attenuated oedema and mechanical allodynia and reduced levels of inflammatory cytokines (IL-1β, TNF-α and IL-6), effects comparable with those of ibuprofen. In the LPS model of pulmonary inflammation, eucalyptol treatment diminished leukocyte infiltration, myeloperoxidase activity and production of TNF-α, IL-1β, IFN-γ and IL-6. Genetic deletion of TRPM8 channels abolished the anti-inflammatory effects of eucalyptol in both models. Eucalyptol was at least sixfold more potent on human, than on mouse TRPM8 channels. A metabolite of eucalyptol, 2-hydroxy-1,8-cineol, also activated human TRPM8 channels.

CONCLUSION AND IMPLICATIONS

Among the pharmacological targets of eucalyptol, TRPM8 channels were essential for its anti-inflammatory effects in mice. Human TRPM8 channels are more sensitive to eucalyptol than rodent TRPM8 channels explaining the higher potency of eucalyptol in humans. Metabolites of eucalyptol could contribute to its anti-inflammatory effects. The development of more potent and selective TRPM8 agonists may yield novel anti-inflammatory agents.

Metadynamics supports molecular dynamics simulation-based binding affinities of eucalyptol and beta-cyclodextrin inclusion complexes

The development of various molecular dynamics methods enables the detailed investigation of association processes, like host–guest complexes, including their dynamics and, additionally, the release of the guest compound.

Gastroprotective Mechanisms of the Monoterpene 1,8-Cineole (Eucalyptol)

Recently, our research group identified and reported 1,8-cineole (CIN), a monoterpene that naturally occur in many aromatic plants, as one of the major constituent of the essential oil from leaves of Hyptis martiusii (EOHM), as well as characterized the gastroprotective action of this oil. The aim of this study was to investigate the mechanisms of action involved in the antiulcer and healing activity of CIN, in order to confirm its correlation with the gastroprotective effect of EOHM. Wistar rats were exposed to different protocols (acute ulceration, gastrointestinal motility and antisecretory activity). In addition, were determinated the involvement of nitric oxide and sulphydryl groups; the levels of gastric mucus, lipid peroxidation, sulphydryl groups and myeloperoxidase activity. The healing ability was evaluated by acetic acid-induced chronic ulcer and histological and immunohistochemical analysis (PCNA, Ki-67 and BrdU). The treatment with CIN inhibited ethanol-, ethanol/HCl- and indomethacin-induced gastric lesions. The highest doses of CIN inhibited gastric emptying, but did not affect intestinal transit. CIN (100 mg/kg) reduced the volume of basal but not stimulated acid secretion. CIN increased levels of mucus (89.3%), prevented depletion of -SH groups (62.6%) and reduced the level of lipid peroxidation (55.3%) and myeloperoxidase activity (59.4%) in the gastric mucosa. In chronic ulcer model, CIN reduced in 43.1% the gastric area lesion, promoted significant regeneration and restoration of the levels of mucus in glandular cells as confirmed by histological analysis; and promoted increase in cell proliferation as evidenced by reactivity for PCNA, Ki-67 and BrdU. This findings demonstrate the role of 1,8-cineole as an important ulcer healing agent and indicate the involvement of antioxidant and cytoprotective mechanisms in the gastroprotective effect of compound. This study also provides evidence that 1,8-cineole is related to the gastroprotective effect of the essential oil of Hyptis martiusii.

1,8-Cineole Ameliorates Steatosis of Pten Liver Specific KO Mice via Akt Inactivation

Hepatocyte-specific Phosphatase and tensin homolog (Pten)-knockout (KO) mice exhibit hepatic lesions analogous to non-alcoholic steatohepatitis (NASH). 1,8-cineole is a monoterpene oxide and it has several biological effects including hepatoprotective effects. In this study we revealed that 1,8-cineole ameliorates NASH of Pten KO mice. Pten KO mice were assigned to a control group without any medication or to a 1,8-cineole group injected with 50 mg/kg i.p. twice per week for eight weeks. At eight weeks, livers from each group were processed to measure triglyceride (TG) content, gene expression analysis, western blot analysis, and histological examination including Oil red O staining. 1,8-cineole ameliorated hepatic steatosis in Pten KO mice, revealed by TG content and Oil red O staining. Moreover, 1,8-cineole downregulated collagen 1a1 expression and improved liver fibrosis. Thus, 1,8-cineole has potential as a candidate to treat NASH by inactivating the Akt/PI3-kinase pathway.

Antioxidant activity of rosemary (Rosmarinus officinalis L.) essential oil and its hepatoprotective potential

BACKGROUND

Natural antioxidant products are increasingly being used to treat various pathological liver conditions considering the role of oxidative stress in their pathogenesis. Rosemary essential oil has already being used as a preservative in food industry due to its antioxidant and antimicrobial activities, but it was shown to possess additional health benefits. The aim of our study was to evaluate the protective effect of rosemary essential oil on carbon tetrachloride - induced liver injury in rats and to explore whether its mechanism of action is associated with modulation of hepatic oxidative status.

METHODS

Chemical composition of isolated rosemary essential oil was determined by gas chromatography and mass spectrometry. Antioxidant activity was determined in vitro using DPPH assay. Activities of enzyme markers of hepatocellular damage in serum and antioxidant enzymes in the liver homogenates were measured using the kinetic spectrophotometric methods.

RESULTS

In this research, we identified 29 chemical compounds of the studied rosemary essential oil, and the main constituents were 1,8-cineole (43.77%), camphor (12.53%), and α-pinene (11.51%). Investigated essential oil was found to exert hepatoprotective effects in the doses of 5 mg/kg and 10 mg/kg by diminishing AST and ALT activities up to 2-fold in serum of rats with carbon tetrachloride-induced acute liver damage. Rosemary essential oil prevented carbon tetrachloride-induced increase of lipid peroxidation in liver homogenates. Furthermore, pre-treatment with studied essential oil during 7 days significantly reversed the activities of antioxidant enzymes catalase, peroxidase, glutathione peroxidase and glutathione reductase in liver homogenates, especially in the dose of 10 mg/kg.

CONCLUSIONS

Our results demonstrate that rosemary essential oil, beside exhibiting free radical scavenging activity determined by DPPH assay, mediates its hepatoprotective effects also through activation of physiological defense mechanisms.

The eucalyptus oil ingredient 1,8-cineol induces oxidative DNA damage

The natural compound 1,8-cineol, also known as eucalyptol, is a major constituent of eucalyptus oil. This epoxy-monoterpene is used as flavor and fragrance in consumer goods as well as medical therapies. Due to its anti-inflammatory properties, 1,8-cineol is also applied to treat upper and lower airway diseases. Despite its widespread use, only little is known about the genotoxicity of 1,8-cineol in mammalian cells. This study investigates the genotoxicity and cytotoxicity of 1,8-cineol in human and hamster cells. First, we observed a significant and concentration-dependent increase in oxidative DNA damage in human colon cancer cells, as detected by the Formamidopyrimidine-DNA glycosylase (Fpg)-modified alkaline comet assay. Pre-treatment of cells with the antioxidant N-acetylcysteine prevented the formation of Fpg-sensitive sites after 1,8-cineol treatment, supporting the notion that 1,8-cineol induces oxidative DNA damage. In the dose range of DNA damage induction, 1,8-cineol did neither reduce the viability of colon cancer cells nor affected their cell cycle distribution, suggesting that cells tolerate 1,8-cineol-induced oxidative DNA damage by engaging DNA repair. To test this hypothesis, hamster cell lines with defects in BRCA2 and Rad51, which are essentials players of homologous recombination (HR)-mediated repair, were treated with 1,8-cineol. The monoterpene induced oxidative DNA damage and subsequent DNA double-strand breaks in the hamster cell lines tested. Intriguingly, we detected a significant concentration-dependent decrease in viability of the HR-defective cells, whereas the corresponding wild-type cell lines with functional HR were not affected. Based on these findings, we conclude that 1,8-cineol is weakly genotoxic, inducing primarily oxidative DNA damage, which is most likely tolerated in DNA repair proficient cells without resulting in cell cycle arrest and cell death. However, cells with deficiency in HR were compromised after 1,8-cineol treatment, suggesting a protective role of HR in response to high doses of 1,8-cineol.

1,8-Cineol inhibits nuclear translocation of NF-κB p65 and NF-κB-dependent transcriptional activity

Natural plant-derived products are commonly applied to treat a broad range of human diseases, including cancer as well as chronic and acute airway inflammation. In this regard, the monoterpene oxide 1,8-cineol, the active ingredient of the clinically approved drug Soledum®, is well-established for the therapy of airway diseases, such as chronic sinusitis and bronchitis, chronic obstructive pulmonary disease and bronchial asthma. Although clinical trials underline the beneficial effects of 1,8-cineol in treating inflammatory diseases, the molecular mode of action still remains unclear. Here, we demonstrate for the first time a 1,8-cineol-depending reduction of NF-κB-activity in human cell lines U373 and HeLa upon stimulation using lipopolysaccharides (LPS). Immunocytochemistry further revealed a reduced nuclear translocation of NF-κB p65, while qPCR and western blot analyses showed strongly attenuated expression of NF-κB target genes. Treatment with 1,8-cineol further led to increased protein levels of IκBα in an IKK-independent matter, while FRET-analyses showed restoring of LPS-associated loss of interaction between NF-κB p65 and IκBα. We likewise observed reduced amounts of phosphorylated c-Jun N-terminal kinase 1/2 protein in U373 cells after exposure to 1,8-cineol. In addition, 1,8-cineol led to decreased amount of nuclear NF-κB p65 and reduction of its target gene IκBα at protein level in human peripheral blood mononuclear cells. Our findings suggest a novel mode of action of 1,8-cineol through inhibition of nuclear NF-κB p65 translocation via IκBα resulting in decreased levels of proinflammatory NF-κB target genes and may therefore broaden the field of clinical application of this natural drug for treating inflammatory diseases.

Inhibitory effect of 1,8-cineole on guinea-pig airway challenged with ovalbumin involves a preferential action on electromechanical coupling

1. 1,8-Cineole is a terpenoid constituent of essential oils with anti-inflammatory properties. It reduces the neural excitability, functions as an antinociceptive agent and has myorelaxant actions in guinea-pig airways. The aim of the present study was to investigate the mechanism underlying the myorelaxant effects of 1,8-cineole in guinea-pig isolated trachea from either naïve guinea-pigs or ovalbumin (OVA)-sensitized animals subjected to antigenic challenge. 2. Isometric recordings were made of the tone of isolated tracheal rings. Rings with an intact epithelium relaxed beyond basal tone in the presence of 1,8-cineole (6.5 x 10(-6) to 2 x 10(-2) mol/L) in a concentration-dependent manner (P < 0.001, anova) with a pD(2) value of 2.23 (95% confidence interval 2.10-2.37). Removal of the epithelium or pretreatment of intact tissue for 15 min with 50 micromol/L N(G)-nitro-l-arginine methyl ester, 5 mmol/L tetraethylammonium, 0.5 micromol/L tetrodotoxin or 5 micromol/L propranolol did not alter the potency (pD(2)) or the maximal myorelaxant effect (E(max)) of 1,8-cineole. 3. 1,8-Cineole also significantly decreased the Schultz-Dale contraction induced by OVA, mainly in preparations from OVA-sensitized animals submitted to antigen challenge. 1,8-Cineole decreased tracheal hyperresponsiveness to KCl and carbachol caused by antigen challenge and almost abolished the concentration-response curves to KCl, whereas it had little effect on the concentration-response curves to carbachol. Under Ca(2+)-free conditions and in the presence of 10(-4) mol/L acetylcholine, neither 1,8-cineole (6.5 x 10(-3) mol/L) nor verapamil (1 x 10(-5) mol/L) affected Ca(2+)-induced contractions, but they almost abolished Ba(2+)-induced contractions. 4. In conclusion, the findings of the present study show that 1,8-cineole is a tracheal myorelaxant that acts preferentially on contractile responses elicited electromechanically.

Pharmacokinetics of 1,8-cineole, a dietary toxin, in the brushtail possum (Trichosurus vulpecula): Significance for feeding

1,8-Cineole (cineole) is a Eucalyptus leaf toxin that defends against predation by herbivores such as the brushtail possum (Trichosurus vulpecula). The aim of the current study was to characterize the pharmacokinetics of cineole in the possum to improve understanding about how possums can avoid cineole toxicity when eating a Eucalyptus diet. Nine male possums were trapped in the wild and acclimated to captivity; a subcutaneous port was then implanted for venous blood sampling. Cineole was administered intravenously (10 and 15 mg kg(-1)) via a lateral tail vein and orally (30, 100 and 300 mg kg(-1)) by gavage, and blood concentrations of cineole and its metabolites were determined by gas chromatography. Cineole had a large terminal volume of distribution (V(z) = 27 l kg(-1)) and a high clearance (43 ml min(-1) kg(-1)), equal to hepatic blood flow. The terminal half-life was approximately 7 h. Oral bioavailability was low (F = 0.05) after low doses, but increased tenfold with dose, probably due to saturable first-pass metabolism. These findings indicate that when possums feed on a cineole diet, they eat until the cineole consumed is sufficient to saturate pre-systemic metabolism, leading to a rapid rise in bioavailability and cineole blood levels, and a cessation of the feeding bout. This is the first report on the pharmacokinetics of a dietary toxin in a wild herbivore, and provides insights into the interactions between the blood concentration of a plant secondary metabolite and the browsing behaviour of a herbivore.

Blood brain barrier permeability in acute liver necrosis of mice

AIM: To study the permeability of the blood brain barrier (BBB) in a mouse model of acute liver necrosis.

METHODS: Male Balb/c mice were divided into 4 groups. In one group, mice were intraperitoneal of lipopolysaccharide (LPS, 10mg/kg) with D-galactosamine (GalN, 800 mg/kg) to induce acute liver necrosis. Other groups were controls. Serum levels of alanine transaminase (ALT) were determined and the liver tissues were fixed for histopathological analysis. The permeability of BBB in mice was investigated with Evans blue (EB).

RESULTS: The serum levels of ALT were increased mildly in mice, which were administration of LPS or GalN alone. And no animals died. But the levels of ALT began to increase at 6 hours (41.89±14.57 mat/L), and reached a maximal level at 12 hours (170.30±16.13 mat/L) after injection with both LPS and GalN. Mice began to die at 6 hours, and at 9 hours after injection, the rate of lethality reached an extremely high level of 66.6%. The liver became massive or submassive necrosis. The concentration of EB in brain was significantly increased in ALF models compared with other groups.

CONCLUSION: The permeability of BBB is increased in acute liver necrosis model. It may be the mechanism of the brain edema.

Cardiovascular effects of 1,8-cineole, a terpenoid oxide present in many plant essential oils, in normotensive rats

The cardiovascular effects of i.v. treatment with 1,8-cineole, a monoterpenic oxide present in many plant essential oils, were investigated in normotensive rats. This study examined (i) whether the autonomic nervous system is involved in the mediation of 1,8-cineole-induced changes in mean aortic pressure (MAP) and heart rate (HR) and (ii) whether the hypotensive effects of 1,8-cineole could result from its vasodilatory effects directly upon vascular smooth muscle. In both pentobarbital-anesthetized and conscious, freely moving rats, bolus injections of 1,8-cineole (0.3-10 mg/kg, i.v.) elicited similar and dose-dependent decreases in MAP. Concomitantly, 1,8-cineole significantly decreased HR only at the highest dose (10 mg/kg). Pretreatment of anesthetized rats with bilateral vagotomy significantly reduced the bradycardic responses to 1,8-cineole (10 mg/kg) without affecting hypotension. In conscious rats, i.v. pretreatment with methylatropine (1 mg/kg), atenolol (1.5 mg/kg), or hexamethonium (30 mg/kg) had no significant effects on the 1,8-cineole-induced hypotension, while bradycardic responses to 1,8-cineole (10 mg/kg) were significantly reduced by methylatropine. In rat isolated thoracic aorta preparations, 1,8-cineole (0.006-2.6 mM) induced a concentration-dependent reduction of the contraction induced by potassium (60 mM). This is the first physiological evidence that i.v. treatment with 1,8-cineole in either anesthetized or conscious rats elicits hypotension; this effect seems related to an active vascular relaxation rather than withdrawal of sympathetic tone.