Farnesol and geraniol chemopreventive activities during the initial phases of hepatocarcinogenesis involve similar actions on cell proliferation and DNA damage, but distinct actions on apoptosis, plasma cholesterol and HMGCoA reductase

Essential Oils: Chemistry and Pharmacological Activities-Part II

The importance of essential oils and their components in the industrial sector is attributed to their chemical characteristics and their application in the development of products in the areas of cosmetology, food, and pharmaceuticals. However, the pharmacological properties of this class of natural products have been extensively investigated and indicate their applicability for obtaining new drugs. Therefore, this review discusses the use of these oils as starting materials to synthesize more complex molecules and products with greater commercial value and clinic potential. Furthermore, the antiulcer, cardiovascular, and antidiabetic mechanisms of action are discussed. The main mechanistic aspects of the chemopreventive properties of oils against cancer are also presented. The data highlight essential oils and their derivatives as a strategic chemical group in the search for effective therapeutic agents against various diseases.

Metabolomics Study of Serum Samples of β-YAC Transgenic Mice Treated with Tenofovir Disoproxil Fumarate

β-thalassemia is one of the most common monogenic disorders and a life-threatening health issue in children. A cost-effective and safe therapeutic approach to treat this disease is to reactivate the γ-globin gene for fetal hemoglobin (HbF) production that has been silenced during infancy. Hydroxyurea (HU) is the only FDA approved HbF inducer. However, its cytotoxicity and inability to respond significantly in all patients pose a need for an HbF inducer with better efficacy. The study describes the serum metabolic alteration in β-YAC transgenic mice treated with Tenofovir disoproxil fumarate (TDF) (n = 5), a newly identified HbF inducer, and compared to the mice groups treated with HU (n = 5) and untreated control (n = 5) using gas chromatography-mass spectrometry. Various univariate and multivariate statistical analyses were performed to identify discriminant metabolites that altered the biological pathways encompassing galactose metabolism, lactose degradation, and inositol. Furthermore, the decreased concentrations of L-fucose and geraniol in TDF-treated mice help in recovering towards normal, decreasing oxidative stress even much better than the HU-treated mice. The proposed study suggested that TDF can reduce the deficiency of blood required for β-thalassemia and can be used for the preclinical study at phase I/II for fetal hemoglobin production.

An Approach to Minimize Tumour Proliferation by Reducing the Formation of Components for Cell Membrane

Isoprenoids are natural compounds essential for a great number of cellular functions. One of them is farnesol (FOH), which can reduce cell proliferation, but its low solubility in aqueous solvents limits its possible clinical use as a pharmacological tool. One alternative is the use of cyclodextrins (CDs) which house hydrophobic molecules forming inclusion complexes. To assess FOH potential application in anticancer treatments, Sulfobutylated β-cyclodextrin Sodium Salt (SBE-β-CD) was selected, due to it has high solubility, approbation by the FDA, and numerous studies that ensure its safety to be administered parenterally or orally without nephrotoxicity associated. The therapeutic action of farnesol and complex were studied in different carcinoma cells, compared with a normal cell line. Farnesol showed selectivity, affecting the viability of colon and liver cancer cells more than in breast cancer cells and fibroblasts. All cells suffered apoptosis after being treated with 150 μM of free FOH, but the complex reduced their cell viability between 50 and 75%. Similar results were obtained for both types of isomers, and the addition of phosphatidylcholine reverses this effect. Finally, cell cycle analysis corroborates the action of FOH as inducer of a G0/G1 phase; when the cells were treated using the complex form, this viability was reduced, reaching 50% in the case of colon and liver, 60% in fibroblasts, and only 75% in breast cancer.

In vivo experimental study to investigate cytogenotoxicity of a contaminated estuary from Southeastern Brazilian Coast

The aim of this study was to evaluate cytogenotoxicity in mammalian cells induced by ingestion of superficial water from SESS. For this purpose, surface water was collected from two points of SESS: São Vicente Channel (SVC) and Piaçaguera Channel (PIC). Four groups (n = 5) of adult male Wistar (8 weeks old) received for 5 days: (a) filtered tap water (water control), (b) tap water with 2.4% of NaCl (saline control), (c) estuarine water from PIC and (d) estuarine water from SVC. Results demonstrated that Ki67 immunoexpression was higher in hepatocytes exposed to both sampling site, while caspase-3 demonstrated downregulation in rat liver exposed to estuarine water. There was also significant increase in micronuclei frequency in bone marrow cells and hepatocytes, and DNA damage in blood and liver of rats exposed to estuarine water from SVC and PIC. In summary, studies with complex mixtures, such as contaminated estuarine water are important since this work confirmed by experiments using in vivo mammalian cells of rats that SESS water are genotoxic, mutagenic and cytotoxic, denoting concern for environmental health.

The identification of farnesoid X receptor modulators as treatment options for nonalcoholic fatty liver disease

INTRODUCTION

The farnesoid-x-receptor (FXR) is a ubiquitously expressed nuclear receptor selectively activated by primary bile acids.

AREA COVERED

FXR is a validated pharmacological target. Herein, the authors review preclinical and clinical data supporting the development of FXR agonists in the treatment of nonalcoholic fatty liver disease.

EXPERT OPINION

Development of systemic FXR agonists to treat the metabolic liver disease has been proven challenging because the side effects associated with these agents including increased levels of cholesterol and LDL-c and reduced HDL-c raising concerns over their long-term cardiovascular safety. Additionally, pruritus has emerged as a common, although poorly explained, dose-related side effect with all FXR ligands, but is especially common with OCA. FXR agonists that are currently undergoing phase 2/3 trials are cilofexor, tropifexor, nidufexor and MET409. Some of these agents are currently being developed as combination therapies with other agents including cenicriviroc, a CCR2/CCR5 inhibitor, or firsocostat an acetyl CoA carboxylase inhibitor. Additional investigations are needed to evaluate the beneficial effects of combination of these agents with statins. It is expected that in the coming years, FXR agonists will be developed as a combination therapy to minimize side effects and increase likelihood of success by targeting different metabolic pathways.

Cholesterol-lowering activity of natural mono- and sesquiterpenoid compounds in essential oils: A review and investigation of mechanisms using in silico protein-ligand docking

Mono- and sesquiterpenoids are the main chemical constituents of essential oils. Essential oils and their constituents have received increasing attention for lipid-lowering properties in both cell and animal models. Despite the chemical diversity of essential oil compounds, the effects of many of these compounds on cholesterol metabolism are highly similar. In this report, we review the literature regarding the effects of essential oils and their terpenoid constituents on cholesterol homeostasis, and explore likely mechanisms using protein-ligand docking. We identified 98 experimental and seven clinical studies on essential oils, isolated compounds, and blends; 100 of these described improvements either in blood cholesterol levels or in sterol metabolic pathways. Our review and docking analysis confirmed two likely mechanisms common to many essential oil compounds: (1) direct agonism of peroxisome-proliferator-activated receptors, and (2) direct interaction with sterol-sensing domains, motifs found in key sterol regulatory proteins including sterol regulatory element binding protein cleavage activating protein and HMG-CoA reductase. Notably, these direct interactions lead to decreased transcription and accelerated degradation of HMG-CoA reductase. Our work suggests that terpene derivatives in essential oils have cholesterol-lowering activity and could potentially work synergistically with statins, however, further high quality studies are needed to establish their clinical efficacy.

Bile acids and their receptors in metabolic disorders

Bile acids are a large family of atypical steroids which exert their functions by binding to a family of ubiquitous cell membrane and nuclear receptors. There are two main bile acid activated receptors, FXR and GPBAR1, that are exclusively activated by bile acids, while other receptors CAR, LXRs, PXR, RORγT, S1PR2and VDR are activated by bile acids in addition to other more selective endogenous ligands. In the intestine, activation of FXR and GPBAR1 promotes the release of FGF15/19 and GLP1 which integrate their signaling with direct effects exerted by theother receptors in target tissues. This network is tuned in a time ordered manner by circadian rhythm and is critical for the regulation of metabolic process including autophagy, fast-to-feed transition, lipid and glucose metabolism, energy balance and immune responses. In the last decade FXR ligands have entered clinical trials but development of systemic FXR agonists has been proven challenging because their side effects including increased levels of cholesterol and Low Density Lipoproteins cholesterol (LDL-c) and reduced High-Density Lipoprotein cholesterol (HDL-c). In addition, pruritus has emerged as a common, dose related, side effect of FXR ligands. Intestinal-restricted FXR and GPBAR1 agonists and dual FXR/GPBAR1 agonists have been developed. Here we review the last decade in bile acids physiology and pharmacology.

Ionone Is More than a Violet's Fragrance: A Review

The term ionone is derived from “iona” (Greek for violet) which refers to the violet scent and “ketone” due to its structure. Ionones can either be chemically synthesized or endogenously produced via asymmetric cleavage of β-carotene by β-carotene oxygenase 2 (BCO2). We recently proposed a possible metabolic pathway for the conversion of α-and β-pinene into α-and β-ionone. The differences between BCO1 and BCO2 suggest a unique physiological role of BCO2; implying that β-ionone (one of BCO2 products) is involved in a prospective biological function. This review focuses on the effects of ionones and the postulated mechanisms or signaling cascades involved mediating these effects. β-Ionone, whether of an endogenous or exogenous origin possesses a range of pharmacological effects including anticancer, chemopreventive, cancer promoting, melanogenesis, anti-inflammatory and antimicrobial actions. β-Ionone mediates these effects via activation of olfactory receptor (OR51E2) and regulation of the activity or expression of cell cycle regulatory proteins, pro-apoptotic and anti-apoptotic proteins, HMG-CoA reductase and pro-inflammatory mediators. α-Ionone and β-ionone derivatives exhibit anti-inflammatory, antimicrobial and anticancer effects, however the corresponding structure activity relationships are still inconclusive. Overall, data demonstrates that ionone is a promising scaffold for cancer, inflammation and infectious disease research and thus is more than simply a violet’s fragrance.

Farnesol attenuates oxidative stress and liver injury and modulates fatty acid synthase and acetyl-CoA carboxylase in high cholesterol-fed rats

Dyslipidemia is a risk factor for cardiovascular disease, steatohepatitis, and progression of liver disorders. This study investigated the protective effect of farnesol (FAR), a sesquiterpene alcohol, against liver injury in high cholesterol diet (HCD)-fed rats, and its modulatory effect on fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC). HCD was supplemented for 10 weeks, and the rats were concurrently treated with FAR. Rats that received HCD exhibited significant elevation of serum cholesterol, triacylglycerols, LDL and vLDL cholesterol, CRP, and pro-inflammatory cytokines and increased values of the cardiovascular risk indices. Serum transaminases, ALP, LDH and CK-MB, and hepatic lipid peroxidation (LPO), cholesterol, and triacylglycerols were increased in HCD-fed rats. Treatment with FAR greatly ameliorated dyslipidemia and liver function, reduced inflammatory mediators, LPO, and hepatic lipid infiltration and enhanced anti-oxidant defenses. FAR suppressed hepatic FAS, ACC, and SREPB-1c mRNA abundance and FAS activity in HDC-fed rats. In addition, molecular docking simulations pinpointed the binding modes of FAR to the active pocket residues of FAS and ACC. In conclusion, FAR possesses a strong anti-hyperlipidemic/anti-hypercholesterolemic activity mediated through its ability to modulate hepatic FAS, ACC, and SREPB-1c. FAR prevented oxidative stress, inflammation, and liver injury induced by HCD. Thus, FAR may represent a promising lipid-lowering agent that can protect against dyslipidemia and its linked metabolic deregulations.

One Hundred Faces of Geraniol

Geraniol is a monoterpenic alcohol with a pleasant rose-like aroma, known as an important ingredient in many essential oils, and is used commercially as a fragrance compound in cosmetic and household products. However, geraniol has a number of biological activities, such as antioxidant and anti-inflammatory properties. In addition, numerous in vitro and in vivo studies have shown the activity of geraniol against prostate, bowel, liver, kidney and skin cancer. It can induce apoptosis and increase the expression of proapoptotic proteins. The synergy of this with other drugs may further increase the range of chemotherapeutic agents. The antibacterial activity of this compound was also observed on respiratory pathogens, skin and food-derived strains. This review discusses some of the most important uses of geraniol.

Low concentrations of sodium arsenite induce hepatotoxicity in prepubertal male rats

Arsenic (As) can contaminate air, soil, water, and organisms through mobilization of natural mineralogical deposits or anthropogenic actions. Inorganic-As compounds are more toxic and widely available in aquatic environments, including drinking water reservoir catchments. Since little is known about its effects on prepubertal mammals, the present study focused on it. Hence, As was administered through drinking water to male Wistar rats from postnatal day 23 to 53. Negative control group received vehicle only (filtered water); As 1 group received AsNaO2 at 0.01 mg L^-1 and As2 group received AsNaO2 at 10 mg L^-1 . It was investigated hepatic and renal toxicity of AsNaO2 (ie, histopathology and apoptosis analysis), as well as its mutagenicity (ie, micronucleus test in liver and bone marrow), cytotoxicity (ie, frequency and type of erythrocytes in blood), and genotoxicity (ie, comet assay in blood). Also, As determination was performed in hepatic and renal tissues. Data obtained revealed that immature organisms present a pattern of arsenic accumulation similar to that observed in adults, suggesting similarity in metabolic processes. In addition, liver showed to be an important target tissue for As toxicity in these experimental conditions, exhibiting infiltrate of defense cells, DNA damages, and increased apoptosis rates.

Advances in Pharmacological Activities of Terpenoids

Terpenoids, the most abundant compounds in natural products, are a set of important secondary metabolites in plants with diverse structures. Terpenoids play key roles in plant growth and development, response to the environment, and physiological processes. As raw materials, terpenoids were also widely used in pharmaceuticals, food, and cosmetics industries. Terpenoids possess antitumor, anti-inflammatory, antibacterial, antiviral, antimalarial effects, promote transdermal absorption, prevent and treat cardiovascular diseases, and have hypoglycemic activities. In addition, previous studies have also found that terpenoids have many potential applications, such as insect resistance, immunoregulation, antioxidation, antiaging, and neuroprotection. Terpenoids have a complex structure with diverse effects and different mechanisms of action. Activities and mechanisms of terpenoids were reviewed in this paper. The development and application prospect of terpenoid compounds were also prospected, which provides a useful reference for new drug discovery and drug design based on terpenoids.

Effects of a moderate iron overload and its interaction with yacon flour, and/or phytate, in the diet on liver antioxidant enzymes and hepatocyte apoptosis in rats

The effect of moderate Fe overload in the diet and its interaction with phytate, and/or yacon flour (YF), recognized as an inhibitor, and facilitator, of Fe absorption, respectively, was evaluated in healthy rats. For this purpose the following parameters were analyzed: (1) apparent iron (Fe), copper (Cu) and zinc (Zn) absorption; (2) blood Fe; (3) blood lipids (cholesterol, tryacylglicerol); (4) blood AST and ALT; (5) liver histology (histopathology, hemosiderin depots, apoptosis index; (6) liver fatty acid incorporation; (7) liver antioxidant enzyme activity. Moderate Fe overload may cause change in some liver markers (hemosiderin depots, apoptosis index and GPx) and blood lipids (total cholesterol and VLDL) and the interaction with yacon flour, and phytate, in the Fe overloaded diets may exert a protective effect on these alterations.

Systematic elucidation of the mechanism of geraniol via network pharmacology

Background

Geraniol is an acyclic monoterpene alcohol, which is extracted from the ethereal oils of aromatic plants. A systematic analysis of its mechanism of action has not yet been carried out.

Methods

In this study, the druggability of geraniol was assessed via Traditional Chinese Medicine Systems Pharmacology Database (TCMSP), and the potential targets of geraniol were identified using the Comparative Toxicogenomics Database (CTD). Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using WebGestalt. Drug-target-pathway networks were constructed using Cytoscape to give a visual view.

Results

Our findings showed that geraniol has superb druggability with 38 putative identified target genes. GO, KEGG, and network analyses revealed that these targets were associated with cancer, inflammatory immunoreactions, and other physiological processes.

Conclusion

Geraniol is predicted to target multiple proteins and pathways that shape a network which can exert systematic pharmacological effects.

Troxerutin subdues hepatic tumorigenesis via disrupting the MDM2-p53 interaction

Hepatocellular carcinoma (HCC) is the leading cause of cancer death worldwide that lacks proper medical prognosis and treatment. In the present study, the anti-tumoral potential of troxerutin (TX), an ethnomedicine, was examined in relation to its effects on the promoter 2-acetylaminofluorene (2-AAF) in N-nitrosodiethylamine (NDEA) initiated HCC, as compared to its effects on HCC induced by NDEA alone. Liver samples from each experimental group were collected and evaluated for histological, biochemical and cellular characterization. The protein expressions of apoptotic and cell proliferation markers were determined via immunohistochemistry and western blotting. Molecular docking was also performed to delineate the inhibitory mechanism of TX on HCC. The results show that only higher doses of TX showed a significant reduction in the incidence of hepatic nodule formation, and they also counteracted NDEA plus 2-AAF induced alterations in the enzymic status. The frequencies of glutathione-S-transferase and proliferating cell nuclear antigen, markers of S phase progression, were markedly reduced during TX treatment. TX also modulated the imbalance in the MDM2-p53 interaction. The molecular docking results confirmed the interaction of TX with the upstream kinases that regulate apoptosis. This study provides evidence that a copious dose of TX is required to counteract the differential mitoinhibitory effect of 2-AAF in NDEA initiated hepatomas, and TX exhibits an anti-tumoral effect via suppressing oxidative stress, regulating liver function enzymes, inhibiting inflammatory responses and modulating MDM2-p53 interactions, thus inducing apoptosis, and thereby suggesting that TX may provide promising therapeutic effects for the chemoprevention of HCC.

Les huiles essentielles comme agents anticancéreux : actualité sur le mode d’action

Le cancer est une maladie complexe qui présente un réel problème de santé publique à travers le monde et cause statiquement sept millions de décès chaque année. Au cours des dernières décennies, la thérapie anticancéreuse a connu un réel bouleversement et un foisonnement de découvertes fondamentales. Plusieurs études accumulatives ont révélé l’activité antitumorale des substances naturelles isolées à partir de plantes. Les huiles essentielles (HE) et leurs constituants ont montré des activités anticancéreuses puissantes in vitro et in vivo. Cependant, les mécanismes d’action sont encore peu étudiés et moins connus. Par ailleurs, leur application dans l’industrie pharmaceutique nécessite une spécificité– sélectivité pharmacodynamique absolue. Dans le présent travail, nous présentons une synthèse des travaux réalisés sur les mécanismes d’actions anticancéreuses des HE et leurs composés bioactifs.

Lipase-Catalyzed Acidolysis of Egg-Yolk Phosphatidylcholine with Citronellic Acid. New Insight into Synthesis of Isoprenoid-Phospholipids

The development of a biotechnological method for the production of new biologically active phosphatidylcholine containing monoterpene citronellic acid (CA) was the aim of this work. Incorporation of citronellic acid (CA) into egg-yolk phosphatidylcholine (PC) in the lipase-catalyzed acidolysis process was studied. Isoprenoid acid CA was used as an acyl donor and five commercially available immobilized lipases were examined as biocatalysts. The effects of organic solvent, enzyme load, reaction time and molar ratio of substrates on the incorporation of citronellic acid (CA) into the phospholipids were evaluated. Modified phospholipid fraction enriched with CA in the sn-1 position (39% of incorporation) was obtained in high 33% yield using Novozym 435 as biocatalyst. In this study a biotechnological method for production of new phospholipid biopreparation enriched with citronellic acid, which can play an important role as a nutraceutical, was applied.

The antitumor effects of geraniol: Modulation of cancer hallmark pathways (Review)

Geraniol is a dietary monoterpene alcohol that is found in the essential oils of aromatic plants. To date, experimental evidence supports the therapeutic or preventive effects of geraniol on different types of cancer, such as breast, lung, colon, prostate, pancreatic, and hepatic cancer, and has revealed the mechanistic basis for its pharmacological actions. In addition, geraniol sensitizes tumor cells to commonly used chemotherapy agents. Geraniol controls a variety of signaling molecules and pathways that represent tumor hallmarks; these actions of geraniol constrain the ability of tumor cells to acquire adaptive resistance against anticancer drugs. In the present review, we emphasize that geraniol is a promising compound or chemical moiety for the development of a safe and effective multi-targeted anticancer agent. We summarize the current knowledge of the effects of geraniol on target molecules and pathways in cancer cells. Our review provides novel insight into the challenges and perspectives with regard to geraniol research and to its application in future clinical investigation.

Farnesol attenuates lipopolysaccharide-induced neurodegeneration in Swiss albino mice by regulating intrinsic apoptotic cascade

Neuronal apoptosis occurs as a sequel of oxidative stress associated with various neuropathies. In this study, we have investigated the protective effect of farnesol, a sequisterpene on lipopolysaccharide (LPS) induced neurodegeneration through modulation of intrinsic apoptotic cascade in the cortex and hippocampus of Swiss albino mice. Intraperitoneal (i.p.) injection of LPS (250 μg/kg b.wt. for 7 days) resulted in elevated levels of lipid peroxidation, protein carbonyls and 8-Hydroxydeoxyguanosine (8OHdG), with subsequent depletion in the antioxidant status and severe histological aberrations. These anomalies were accompanied by increased expressions of pro-apoptotic Bax, caspase-3 and p53 with decrease in anti-apoptotic Bcl-2. Farnesol treatment (100mg/kg b.wt.) ameliorated LPS-induced oxidative stress by enhancing the antioxidant defense system as evident from the increased levels of SOD, CAT, GSH and GST and exhibited protected cellular morphology manifested from histopathological and nissl staining analyses. Farnesol treatment also reduced the expulsion of cytochrome c from mitochondria and downregulated caspase 3 activation as revealed by immunoblot analysis. Furthermore, farnesol treatment reduced the expression of Bax and antagonized LPS-induced decrease in anti-apoptotic Bcl-2. Results of this study show that farnesol exerts neuroprotective effect by regulating intrinsic apoptotic cascade through its antioxidant effect during LPS-induced neurodegeneration.

Farnesol activates the intrinsic pathway of apoptosis and the ATF4-ATF3-CHOP cascade of ER stress in human T lymphoblastic leukemia Molt4 cells

In this study, we demonstrate that treatment of T lymphoblastic leukemic Molt4 cells with farnesol activates the apoptosome via the intrinsic pathway of apoptosis. This induction was associated with changes in the level of intracellular potassium and calcium, the dissipation of the mitochondrial and plasma membrane potential, release of cytochrome c, activation of several caspases, and PARP cleavage. The induction of apoptosis by farnesol was inhibited by the addition of the pan-caspase inhibitor Z-VAD-fmk and by the exogenous expression of the anti-apoptotic protein Bcl2. Analysis of the gene expression profiles by microarray analysis revealed that farnesol increased the expression of several genes related to the unfolded protein response (UPR), including CHOP and CHAC1. This induction was associated with the activation of the PERK-eIF2α-ATF3/4 cascade, but not the XBP-1 branch of the UPR. Although farnesol induced activation of the ERK1/2, p38, and JNK pathways, inhibition of these MAPKs had little effect on farnesol-induced apoptosis or the induction of UPR-related genes. Our data indicate that the induction of apoptosis in leukemic cells by farnesol is mediated through a pathway that involves activation of the apoptosome via the intrinsic pathway and induction of the PERK-eIF2α-ATF3/4 cascade in a manner that is independent of the farnesol-induced activation of MAPKs.

Modulation by geraniol of gene expression involved in lipid metabolism leading to a reduction of serum-cholesterol and triglyceride levels

BACKGROUND

Geraniol (G) is a natural isoprenoid present in the essential oils of several aromatic plants, with various biochemical and pharmacologic properties. Nevertheless, the mechanisms of action of G on cellular metabolism are largely unknown.

HYPOTHESIS/PURPOSE

We propose that G could be a potential agent for the treatment of hyperlipidemia that could contribute to the prevention of cardiovascular disease. The aim of the present study was to advance our understanding of its mechanism of action on cholesterol and TG metabolism.

STUDY DESIGN/METHODS

NIH mice received supplemented diets containing 25, 50, and 75 mmol G/kg chow. After a 3-week treatment, serum total-cholesterol and triglyceride levels were measured by commercial kits and lipid biosynthesis determined by the [(14)C] acetate incorporated into fatty acids plus nonsaponifiable and total hepatic lipids of the mice. The activity of the mRNA encoding HMGCR-the rate-limiting step in cholesterol biosynthesis-along with the enzyme levels and catalysis were assessed by real-time RT-PCR, Western blotting, and HMG-CoA-conversion assays, respectively. In-silico analysis of several genes involved in lipid metabolism and regulated by G in cultured cells was also performed. Finally, the mRNA levels encoded by the genes for the low-density-lipoprotein receptor (LDLR), the sterol-regulatory-element-binding transcription factor (SREBF2), the very-low-density-lipoprotein receptor (VLDLR), and the acetyl-CoA carboxylase (ACACA) were determined by real-time RT-PCR.

RESULTS

Plasma total-cholesterol and triglyceride levels plus hepatic fatty-acid, total-lipid, and nonsaponifiable-lipid biosynthesis were significantly reduced by feeding with G. Even though an up-regulation of the mRNA encoding HMGCR occurred in the G treated mouse livers, the protein levels and specific activity of the enzyme were both inhibited. G also enhanced the mRNAs encoding the LDL and VLDL receptors and reduced ACACA mRNA, without altering the transcription of the mRNA encoding the SREBF2.

CONCLUSIONS

The following mechanisms may have mediated the decrease in plasma lipids levels in mice: a down-regulation of hepatocyte-cholesterol synthesis occurred as a result of decreased HMGCR protein levels and catalytic activity; the levels of LDLR mRNA became elevated, thus suggesting an increase in the uptake of serum LDL, especially by the liver; and TG synthesis became reduced very likely because of a decrease in fatty-acid synthesis.

Geraniol, alone and in combination with pioglitazone, ameliorates fructose-induced metabolic syndrome in rats via the modulation of both inflammatory and oxidative stress status

Geraniol (GO) potent antitumor and chemopreventive effects are attributed to its antioxidant and anti-inflammatory properties. In the current study, the potential efficacy of GO (250 mg/kg) in ameliorating metabolic syndrome (MetS) induced by fructose in drinking water was elucidated. Moreover, the effect of pioglitazone (5 and 10 mg/kg; PIO) and the possible interaction of the co-treatment of GO with PIO5 were studied in the MetS model. After 4 weeks of treatment, GO and/or PIO reduced the fasting blood glucose and the glycemic excursion in the intraperitoneal glucose tolerance test. GO and PIO5/10 restrained visceral adiposity and partly the body weight gain. The decreased level of peroxisome proliferator activated receptor (PPAR)-γ transcriptional activity in the visceral adipose tissue of MetS rats was increased by single treatment regimens. Though GO did not affect MetS-induced hyperinsulinemia, PIO5/10 lowered it. Additionally, GO and PIO5/10 suppressed glycated hemoglobin and the receptor for advanced glycated end products (RAGE). These single regimens also ameliorated hyperuricemia, the disrupted lipid profile, and the elevated systolic blood pressure evoked by MetS. The rise in serum transaminases, interleukin-1β, and tumor necrosis factor-α, as well as hepatic lipid peroxides and nitric oxide (NO) was lowered by the single treatments to different extents. Moreover, hepatic non-protein thiols, as well as serum NO and adiponectin were enhanced by single regimens. Similar effects were reached by the combination of GO with PIO5; however, a potentiative interaction was noted on fasting serum insulin level, while synergistic effects were reflected as improved insulin sensitivity, as well as reduced RAGE and triglycerides. Therefore, GO via the transcriptional activation of PPAR-γ reduces inflammation and free radical injury produced by MetS. Thereby, these effects provide novel mechanistic insights on GO management of MetS associated critical risk factors. Moreover, the co-administration of GO to PIO5 exalted the antidiabetic drug anti-MetS efficacy.

Monoterpene (-)-citronellal affects hepatocarcinoma cell signaling via an olfactory receptor

Terpenes are the major constituents of essential oils in plants. In recent years, terpenes have become of clinical relevance due to their ability to suppress cancer development. Their effect on cellular proliferation has made them promising agents in the prevention or treatment of many types of cancer. In the present study, a subset of different monoterpenes was investigated for their molecular effects on the hepatocellular carcinoma cell line Huh7. Using fluorometric calcium imaging, acyclic monoterpene (-)-citronellal was found to induce transient Ca(2+) signals in Huh7 cells by activating a cAMP-dependent signaling pathway. Moreover, we detected the (-)-citronellal-activated human olfactory receptor OR1A2 at the mRNA and protein levels and demonstrated its potential involvement in (-)-citronellal-induced calcium signaling in Huh7 cells. Furthermore, activation of OR1A2 results in phosphorylation of p38 MAPK and reduced cell proliferation, indicating an effect on hepatocellular carcinoma progression. Here, we provide for the first time data on the molecular mechanism evoked by (-)-citronellal in human hepatocellular carcinoma cells. The identified olfactory receptor could serve as a potential therapeutic target for cancer diagnosis and treatment.

Cancer chemopreventive effect of Spirogyra neglecta (Hassall) Kützing on diethylnitrosamine-induced hepatocarcinogenesis in rats

Spirogyra neglecta, a freshwater green alga, is a local food in the northern and northeastern parts of Thailand. This investigation explored the anticarcinogenicity of S neglecta and its possible cancer chemopreventive mechanisms in rats divided into 14 groups. Groups 1 and 10 served as positive and negative control groups, respectively. Groups 1-9 were intraperitoneally injected with diethylnitrosamine (DEN) once a week for 3 weeks. Groups 10-14 received normal saline instead. One week after the last DEN injection, groups 2-5 were administered for 9 consecutive weeks various doses of S neglecta extract (SNE) and dried S neglecta (SND), mixed with basal diet. Groups 6-9 and 11-14 similarly were administered various doses of SNE and SND starting from the first week of the experiment. Administration of SNE and SND was not associated with formation of glutathione-S- transferase placental form (GST-P) positive foci in rat liver. SNE and SND during initiation phase significantly reduced the number of GST-P positive foci in rats injected with DEN. The number of GST-P also diminished in groups treated with SNE and SND after injection with DEN, except for the low dose extract group. SNE showed stronger anticarcinogenic potency than SND. Furthermore, SNE also decreased the number of Ki-67 positive cells. However, the numbers of TUNEL-positive cells in the liver of the SNE-treated groups were not statistically different from the controls. The GST activity in 50 mg/kg bw of SNE and 1% of SND groups was significantly increased as compared to the positive control. In conclusion, Spirogyra neglecta (Hassall) Kutzing showed cancer chemopreventive properties at the early stages of diethylnitrosamine-induced hepatocarcinogenesis in rats. Possible inhibitory mechanisms include enhancement of the activities of some detoxifying enzymes and/or suppression of precancerous cells.

Genotoxicity and cytotoxicity induced by municipal effluent in multiple organs of Wistar rats

The aim of this study was to evaluate cytotoxicity and genotoxicity in multiple organs of rats induced by municipal effluent released by submarine outfall in city of Santos. A total of 20 male Wistar rats were exposed to effluents by drinking water ad libitum at concentrations of 0, 10, 50, and 100 % for 30 days. Microscopic analysis revealed severe lesions such as necrosis and hemorrhagic areas in liver and kidney from animals exposed to effluent at 50 and 100 % concentration. DNA damage in peripheral blood, liver, and kidney cells were detected by comet assay at higher concentrations of effluent. Moreover, a decrease DNA repair capacity was detected in liver cells. Significant statistical differences (p<0.05) for micronucleated cells from liver were noticed at 50 % concentration of effluent. Taken together, our results demonstrate that municipal effluent is able to induce cytotoxicity and genotoxicity in multiple organs of Wistar rats.

Antitumor activity of monoterpenes found in essential oils

Cancer is a complex genetic disease that is a major public health problem worldwide, accounting for about 7 million deaths each year. Many anticancer drugs currently used clinically have been isolated from plant species or are based on such substances. Accumulating data has revealed anticancer activity in plant-derived monoterpenes. In this review the antitumor activity of 37 monoterpenes found in essential oils is discussed. Chemical structures, experimental models, and mechanisms of action for bioactive substances are presented.

Suppression by geraniol of the growth of A549 human lung adenocarcinoma cells and inhibition of the mevalonate pathway in culture and in vivo: potential use in cancer chemotherapy

Geraniol (G)-a natural compound present in the essential oils of many aromatic plants-has attracted interest for its potential antitumor effects. The molecular mechanisms of the growth inhibition and apoptosis induced by G in cancer cells, however, remain unclear. In this study, we investigated the effects of G on cell proliferation in culture in A549 cells and in vivo in those same tumor cells implanted in nude mice fed diets supplemented with 25, 50, and 75 mmol G/kg. We demonstrated that G caused a dose- and time-dependent growth inhibition of A549 cells and tumor growth in vivo along with an induction of apoptosis. Moreover, further in vivo assays indicated that G decreased the levels of 3-hydroxymethylglutarylcoenzyme-A reductase-the rate-limiting enzyme in cholesterogenesis-in a dose-dependent manner along with cholesterogenesis and cholesterolemia in addition to reducing the amount of membrane-bound Ras protein. These results showed that the doses of G used in this work, though nontoxic to animals, clearly inhibited the mevalonate pathway, which is closely linked to cell proliferation and increased apoptosis in A549 tumors, but not in normal mouse-liver cells. Accordingly, we suggest that G displays significant antitumor activity and should be a promising candidate for cancer chemotherapy.

Farnesol induces apoptosis of DU145 prostate cancer cells through the PI3K/Akt and MAPK pathways

The aim of this study was to investigate the effect of farnesol on the induction of apoptosis in DU145 prostate cancer cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay showed that cell proliferation decreased significantly in a dose- and time-dependent manner. 4',6-Diamidino-2-phenylindole staining showed that chromatin condensation in cells treated with 60 µM of farnesol was markedly higher than in the control groups. Farnesol increased the expression of p53, p-c-Jun N-terminal kinase, cleaved-caspase-3, Bax, and cleaved-caspase-9, but decreased the expression of p-phosphatidylinositol-3-kinase (PI3K), p-Akt, p-p38, Bcl-2, and p-extracellular signal-regulated protein kinase, in a dose-dependent manner. The apoptotic cell ratio increased in a dose-dependent manner. The tumor growth inhibitory effect of farnesol was investigated in a mouse model. Compared to the control group, tumor volume decreased significantly in the group administered 50 mg/kg farnesol. Apoptosis was frequently detected in this same group by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The results indicated that farnesol induced apoptosis of DU145 prostate cancer cells through the PI3K/Akt and mitogen-activated protein kinase signaling pathways.

Transcriptomic responses provide a new mechanistic basis for the chemopreventive effects of folic acid and tributyrin in rat liver carcinogenesis

The steady increase in the incidence and mortality of hepatocellular carcinoma (HCC) signifies a crucial need to understand better its pathogenesis to improve clinical management and prevention of the disease. The aim of this study was to investigate molecular mechanisms for the chemopreventive effects of folic acid and tributyrin alone or in combination on rat hepatocarcinogenesis. Male Wistar rats were subjected to a classic "resistant hepatocyte" model of liver carcinogenesis and treated with folic acid and tributyrin alone or in combination for 5 weeks during promotion stage. Treatment with folic acid and tributyrin alone or in combination strongly inhibited the development of glutathione-S-transferase placental form (GSTP)-positive foci. Microarray analysis showed significant changes in gene expression. A total of 498, 655 and 940 of differentially expressed genes, involved in cell cycle, p53-signaling, angiogenesis and Wnt pathways, was identified in the livers of rats treated with folic acid, tributyrin or folic acid and tributyrin. A detailed analysis of these differentially expressed genes revealed that treatments inhibited angiogenesis in the preneoplastic livers. This was evidenced by the fact that 30 out of 77 differentially expressed genes common to all three treatments are involved in the regulation of the angiogenesis pathway. The inhibition of angiogenesis was confirmed by reduced levels of CD34 protein. In conclusion, the tumor-suppressing activity of folic acid and tributyrin is associated with inhibition of angiogenesis at early stages of rat liver carcinogenesis. Importantly, the combination of folic acid and tributyrin has stronger chemopreventive effect than each of the compounds alone.

Mouse model of mevalonate kinase deficiency: comparison of cytokine and chemokine profile with that of human patients

BACKGROUND

Mevalonate kinase deficiency (MKD) is a rare genetic autoinflammatory disease caused by blocking of the enzyme mevalonate kinase in the pathway of cholesterol and isoprenoids. The pathogenic mechanism originating an immune response in MKD patients has not been clearly understood.

METHODS

We investigated the dysregulation of expression of selected cytokines and chemokines in the serum of MKD patients. The results have been compared with those observed in an MKD mouse model obtained by treating the mice with aminobisphosphonate, a molecule that is able to inhibit the cholesterol pathway, mimicking the genetic block characteristic of the disease.

RESULTS

Interleukin (IL)-1β, IL-5, IL-6, IL-9, IL-17, granulocyte colony-stimulating factor, monocyte chemotactic protein-1, tumor necrosis factor-α, and IL-4 expression were dysregulated in sera from MKD patients and mice. Moreover, geraniol, an exogenous isoprenoid, when administered to MKD mice, restored cytokines and chemokines levels with values similar to those of untreated mice.

CONCLUSION

Our findings, which were obtained in patients and a mouse model mimicking the human disease, suggest that these cytokines and chemokines could be MKD specific and that isoprenoids could be considered as potential therapeutic molecules. The mouse model, even if with some limitations, was robust and suitable for routine testing of potential MKD drugs.

Determination of E,E-farnesol in Makgeolli (rice wine) using dynamic headspace sampling and stir bar sorptive extraction coupled with gas chromatography-mass spectrometry

In this paper, we analysed the volatile and semi-volatile compounds, including E,E-farnesol in Makgeolli which is a traditional type of Korean fermented rice wines. Forty-one compounds including alcohols, 1-butanol-3-methyl acetate, E,E-farnesol, stearol, and phytane, were separated and quantified by dynamic headspace sampling (DHS) and stir bar sorptive extraction (SBSE) coupled with gas chromatography-mass spectrometry. SBSE has been found to be an effective method for analysing E,E-farnesol levels in Makgeolli. The experimental parameters related to the extraction efficiency of the SBSE method, such as ethanol concentration and filtration, were studied and optimised. The linear dynamic range of the SBSE method for E,E-farnesol ranged from 0.02 to 200ngml(-1) with R(2)=0.9974. The limit of detection and limit of quantification of the SBSE method were 0.02 and 0.05ngml(-1), respectively. The relative standard deviation of intra- and inter-day reproducibility was less than 6.2% and 9.9%, respectively.

Geraniol inhibits murine skin tumorigenesis by modulating COX-2 expression, Ras-ERK1/2 signaling pathway and apoptosis

Geraniol (GOH), a naturally occurring monoterpene, has been shown to have antiproliferative, cell cycle arrest and apoptosis-inducing effects, and represents a promising cancer chemopreventive agent. In the present study, we investigated the chemopreventive potential of GOH (50 and 100 mg kg(-1) body weight) against 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol 13-acetate (TPA)-mediated skin tumorigenesis in Swiss albino mice. The topical treatment of GOH, 30 min prior to TPA (2 µg per 200 µl of acetone) treatment significantly inhibited TPA-induced skin edema, hyperplasia, COX-2 induction and oxidative stress response. The GOH treatment also resulted in reduction of TPA-induced ornithine decarboxylase activity and [(3) H] thymidine incorporation by 53% (P < 0.001) and 41% (P < 0.001), respectively. We found that GOH treatment significantly inhibited the tumor incidence and number of tumors (P < 0.001) and extended the latency period from 4 weeks in DMBA/TPA treatment group to 10 weeks in GOH-pretreated mice. Furthermore, we observed that GOH treatment significantly suppressed the Ras/Raf/ERK1/2 signaling pathway in skin tumor. Consistently, GOH-treated skin tumors showed reduced expression of Bcl-2 and increased expression of Bax in these lesions. Thus, it was concluded that GOH inhibits DMBA/TPA-mediated skin tumorigenesis by attenuating the Ras proliferation pathway and inducing pro-apoptotic state via inhibition of oxidative stress response and inflammation.

Chemopreventive efficacy of geraniol against 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis

The status of lipid peroxidation, antioxidants, and detoxification enzymes were used as biochemical end points to assess the chemopreventive potential of geraniol, a monoterpene, in 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Topical application of 0.5% DMBA in liquid paraffin, three times a week, for 14 weeks developed well-differentiated squamous cell carcinoma in the buccal pouch of golden Syrian hamsters. Although 100% tumor formation was noticed in hamsters treated with DMBA alone, intragastric administration of geraniol, at a dose of 250 mg/kg body weight (b.w.) to DMBA-treated hamster completely prevented the formation of oral tumors. Furthermore, geraniol significantly reduced lipid peroxidation by-products and improved the status of enzymatic and non-enzymatic antioxidants as well as modulated the status of phase I and phase II detoxification enzymes, favoring the excretion of carcinogenic metabolite, during DMBA-induced oral carcinogenesis. The present study concludes that the chemopreventive potential of geraniol relies on its anti-lipid peroxidative and antioxidant function as well as modulatory effects on phase I and II detoxification enzymes to excrete the carcinogenic metabolite, during DMBA-induced hamster buccal pouch carcinogenesis.

Farnesol, an isoprenoid, improves metabolic abnormalities in mice via both PPARα-dependent and -independent pathways

Peroxisome proliferator-activated receptors (PPARs) control energy homeostasis. In this study, we showed that farnesol, a naturally occurring ligand of PPARs, could ameliorate metabolic diseases. Obese KK-Ay mice fed a high-fat diet (HFD) containing 0.5% farnesol showed significantly decreased serum glucose level, glucosuria incidence, and hepatic triglyceride contents. Farnesol-containing HFD upregulated the mRNA expressions of PPARα target genes involved in fatty acid oxidation in the liver. On the other hand, farnesol was not effective in upregulating the mRNA expressions of PPARγ target genes in white adipose tissues. Experiments using PPARα-deficient [(-/-)] mice revealed that the upregulation of fatty acid oxidation-related genes required PPARα function, but the suppression of hepatic triglyceride accumulation was partially PPARα-dependent. In hepatocytes isolated from the wild-type and PPARα (-/-) mice, farnesol suppressed triglyceride synthesis. In luciferase assay, farnesol activated both PPARα and the farnesoid X receptor (FXR) at similar concentrations. Moreover, farnesol increased the mRNA expression level of a small heterodimer partner known as one of the FXR target genes and decreased those of sterol regulatory element-binding protein-1c and fatty acid synthase in both the wild-type and PPARα (-/-) hepatocytes. These findings suggest that farnesol could improve metabolic abnormalities in mice via both PPARα-dependent and -independent pathways and that the activation of FXR by farnesol might contribute partially to the PPARα-independent hepatic triglyceride content-lowering effect. To our knowledge, this is the first study on the effect of the dual activators of PPARα and FXR on obesity-induced metabolic disorders.