Anticancer effects of phytol against Sarcoma (S-180) and Human Leukemic (HL-60) cancer cells

Phytol (Pyt), a diterpenoid, possesses many important bioactivities. This study evaluates the anticancer effects of Pyt on sarcoma 180 (S-180) and human leukemia (HL-60) cell lines. For this purpose, cells were treated with Pyt (4.72, 7.08, or 14.16 μM) and a cell viability assay was performed. Additionally, the alkaline comet assay and micronucleus test with cytokinesis were also performed using doxorubicin (6 μM) and hydrogen peroxide (10 mM) as positive controls and stressors, respectively. Results revealed that Pyt significantly reduced the viability and rate of division in S-180 and HL-60 cells with IC50 values of 18.98 ± 3.79 and 1.17 ± 0.34 μM, respectively. Pyt at 14.16 μM exerted aneugenic and/or clastogenic effects in S-180 and HL-60 cells, where the number of micronuclei and other nuclear abnormalities (e.g., nucleoplasmic bridges and nuclear buds) were frequently observed. Moreover, Pyt at all concentrations induced apoptosis and showed necrosis at 14.16 μM, suggesting its anticancer effects on the tested cancer cell lines. Taken together, Pyt showed promising anticancer effects, possibly through inducing apoptosis and necrosis mechanisms, and it exerted aneugenic and/or clastogenic effects on the S-180 and HL-60 cell lines.

Phytol from Faeces Bombycis alleviated migraine pain by inhibiting Nav1.7 sodium channels

ETHNOPHARMACOLOGICAL RELEVANCE

Faeces Bombycis (silkworm excrement, called Cansha in Chinese), is the dried faeces of the larvae of silkworm. According to the theories of traditional Chinese medicine recorded in "Compendium of Materia Medica", Faeces Bombycis has often been prescribed in traditional Chinese medicine for the treatment of recurrent headache, rheumatalgia, rubella and itching et al. However, the bioactive components and their exact mechanisms underlying the pain-relieving effects remain to be revealed.

AIM OF THE STUDY

The present study aimed to evaluate the analgesic effect of Faeces Bombycis extract (FBE) on migraine, explore the main active constituents and investigate the pharmacological mechanisms for its pain relief.

MATERIALS AND METHODS

The bioactivity of different extracts from Faeces Bombycis was tracked by the nitroglycerin (NTG)-induced migraine model on rats and identified by NMR spectroscopic data. Whole-cell patch clamp technique, an electrophysiological method, was used to screen the potential targets and study the mechanism of action for the bioactive compound. The following targets have been screened and studied, including Nav1.7 sodium channels, Nav1.8 sodium channels, TRPV1 channels and TRPA1 channels. The trigeminal ganglion neurons were further used to study the effects of the identified compound on neuronal excitability.

RESULTS

By testing the bioactivity of the different extracts proceedingly, fraction petroleum ether showed higher anti-migraine activity. Through further step-by-step isolations, 7 compounds were isolated. Among them, phytol was identified with the highest yield and displayed a potent anti-migraine effect. By screening the potential ion channel targets for migraine, phytol was found to preferentially block the inactivated state of Nav1.7 sodium channels with half-inhibition concentration 0.32 ± 0.05 μM. Thus, the effects of phytol on the biophysical properties of Nav1.7 sodium channels were further characterized. Phytol induced a hyperpolarizing shift of voltage-dependent inactivation and slowed the recovery from inactivation. The affinity of phytol became weaker in the inactivation-deficient Nav1.7 channels (Nav1.7-WCW). And such an effect was independent on the local anesthetic site (Nav1.7 F1737A). Consistent with the data from recombinant channels, the compound also displayed state-dependent inhibition on neuronal sodium channels and further decreased the neuronal excitability in trigeminal ganglion neurons. Moreover, besides Nav1.7 channel, phytol also antagonized the activation of TRPV1 and TRPA1 channels at micromolar concentrations with a weaker affinity.

CONCLUSION

Our results demonstrated that phytol is the major anti-migraine ingredient of Faeces Bombycis and alleviates migraine behaviors by acting on Nav1.7 sodium channels in the trigeminal ganglion neurons. This study provided evidences for the therapeutic application of Faeces Bombycis and phytol on migraine disease.

Tissue Proteome of 2-Hydroxyacyl-CoA Lyase Deficient Mice Reveals Peroxisome Proliferation and Activation of ω-Oxidation

Peroxisomal fatty acid α-oxidation is an essential pathway for the degradation of β-carbon methylated fatty acids such as phytanic acid. One enzyme in this pathway is 2-hydroxyacyl CoA lyase (HACL1), which is responsible for the cleavage of 2-hydroxyphytanoyl-CoA into pristanal and formyl-CoA. Hacl1 deficient mice do not present with a severe phenotype, unlike mice deficient in other α-oxidation enzymes such as phytanoyl-CoA hydroxylase deficiency (Refsum disease) in which neuropathy and ataxia are present. Tissues from wild-type and Hacl1^−/− mice fed a high phytol diet were obtained for proteomic and lipidomic analysis. There was no phenotype observed in these mice. Liver, brain, and kidney tissues underwent trypsin digestion for untargeted proteomic liquid chromatography-mass spectrometry analysis, while liver tissues also underwent fatty acid hydrolysis, extraction, and derivatisation for fatty acid gas chromatography-mass spectrometry analysis. The liver fatty acid profile demonstrated an accumulation of phytanic and 2-hydroxyphytanic acid in the Hacl1^−/− liver and significant decrease in heptadecanoic acid. The liver proteome showed a significant decrease in the abundance of Hacl1 and a significant increase in the abundance of proteins involved in PPAR signalling, peroxisome proliferation, and omega oxidation, particularly Cyp4a10 and Cyp4a14. In addition, the pathway associated with arachidonic acid metabolism was affected; Cyp2c55 was upregulated and Cyp4f14 and Cyp2b9 were downregulated. The kidney proteome revealed fewer significantly upregulated peroxisomal proteins and the brain proteome was not significantly different in Hacl1^−/− mice. This study demonstrates the powerful insight brought by proteomic and metabolomic profiling of Hacl1^−/− mice in better understanding disease mechanism in fatty acid α-oxidation disorders.

Phytol, a Constituent of Chlorophyll, Induces Root-Knot Nematode Resistance in Arabidopsis via the Ethylene Signaling Pathway

Root-knot nematodes (RKNs; Meloidogyne spp.) parasitize the roots or stems of a wide range of plant species, resulting in severe damage to the parasitized plant. The phytohormone ethylene (ET) plays an important role in signal transduction pathways leading to resistance against RKNs. However, little is currently known about the induction mechanisms of ET-dependent RKN resistance. Inoculation of Arabidopsis thaliana roots with RKNs decreased chlorophyll contents in aerial parts of the plant. We observed accumulation of phytol, a constituent of chlorophyll and a precursor of tocopherols, in RKN-parasitized roots. Application of sclareol, a diterpene that has been shown to induce ET-dependent RKN resistance, to the roots of Arabidopsis plants increased phytol contents in roots accompanied by a decrease in chlorophyll in aerial parts. Exogenously applied phytol inhibited RKN penetration of roots without exhibiting nematicidal activity. This phytol-induced inhibition of RKN penetration was attenuated in the ET-insensitive Arabidopsis mutant ein2-1. Exogenously applied phytol enhanced the production of α-tocopherol and expression of VTE5, a gene involved in tocopherol production, in Arabidopsis roots. α-Tocopherol exerted induction of RKN resistance similar to that of phytol and showed increased accumulation in roots inoculated with RKNs. Furthermore, the Arabidopsis vte5 mutant displayed no inhibition of RKN penetration in response to phytol. These results suggest that exogenously applied phytol induces EIN2-dependent RKN resistance, possibly via tocopherol production.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

The therapeutic potential of phytol towards Trypanosoma congolense infection and the inhibitory effects against trypanosomal sialidase

The search for novel therapeutic candidates against animal trypanosomiasis is an ongoing scientific endevour because of the negative impacts of the disease to the African livestock industry. In this study, the in vivo therapeutic potentials of phytol toward Trypanosoma congolense infection and the inhibitory effects on trypanosomal sialidase were investigated. Rats were infected with T. congolense and administered daily oral treatment of 50 and 100 mg/kg BW of phytol. Within the first 10 days of the treatment, no antitrypanosomal activity was recorded but a moderate trypanostatic activity was observed from day 17-day 21 pi. However, at 100 mg/kg BW, phytol demonstrated a significant (p < 0.05) ameliorative potentials toward T. congolense-induced host-associated pathological damages such as anaemia, hepatic and renal damages; and the data was comparable to diminazine aceturate. Moreover, the T. congolense caused a significant (p < 0.05) increase in free serum sialic acid level which was significantly (p < 0.05) prevented in the presence of phytol (100 mg/kg BW). In an in vitro analysis, phytol inhibited partially purified T. congolense sialidase using an uncompetitive inhibition pattern with inhibition binding constant of 261.24 μmol/mL. Subsequently, molecular docking revealed that the compound binds to homology modelled trypanosomal sialidase with a binding free energy of -6.7 kcal/mol which was mediated via a single hydrogen bond while Trp324 and Pro274 were the critical binding residues. We concluded that phytol has moderate trypanostatic activity but with a great potential in mitigating the host-associated cellular damages while the anaemia amelioration was mediated, in part, through the inhibition of sialidase.

Anti-diarrheal activities of phytol along with its possible mechanism of action through in-vivo and in-silico models

Phytol (PHY), a chlorophyll-derived diterpenoid, exhibits numerous pharmacological properties, including antioxidant, antimicrobial, and anticancer activities. This study evaluates the anti-diarrheal effect of phytol (PHY) along with its possible mechanism of action through in-vivo and in-silico models. The effect of PHY was investigated on castor oil-induced diarrhea in Swiss mice by using prazosin, propranolol, loperamide, and nifedipine as standards with or without PHY. PHY at 50 mg/kg (p.o.) and all other standards exhibit significant (p &lt; 0.05) anti-diarrheal effect in mice. The effect was prominent in the loperamide and propranolol groups. PHY co-treated with prazosin and propranolol was found to increase in latent periods along with a significant reduction in diarrheal section during the observation period than other individual or combined groups. Furthermore, molecular docking studies also suggested that PHY showed better interactions with the α- and β-adrenergic receptors, especially with α-ADR1a and β-ADR1. In the former case, PHY showed interaction with hydroxyl group of Ser192 at a distance of 2.91Å, while in the latter it showed hydrogen bond interactions with Thr170 and Lys297 with a distance of 2.65 and 2.72Å, respectively. PHY exerted significant anti-diarrheal effect in Swiss mice, possibly through blocking α- and β-adrenergic receptors.

Phytol anti-inflammatory activity: Pre-clinical assessment and possible mechanism of action elucidation

Phytol (PHY) is an acyclic natural diterpene alcohol and a chlorophyll constituent that exhibits several pharmacological effects, such as anticancer, antioxidant, and antimicrobial. Here, we aimed to assess the PHY anti-inflammatory effect in vitro and in vivo, and to deepen knowledge on the possible mechanism of action. For this purpose, egg albumin (in vitro) test was performed by using acetyl salicylic acid (ASA) as a standard nonsteroidal anti-inflammatory drugs (NSAID). For in vivo test, male Wistar albino rats were treated (intraperitoneally) with 100 mg/kg of PHY and/or standard NSAIDs ASA (100 mg/kg) and diclofenac sodium (Diclo-Na, 10 mg/kg) to evaluate the combined effect of PHY in formalin-induced paw edema model. Furthermore, an in silico (CADD) study was accomplished to assess the effect of PHY against cyclooxygenase (COX)-1 and 2 enzymes, nuclear factor kappa B (NF-κB), and interleukin-1β (IL-1β). Results revealed that PHY exhibits dose-dependent anti-inflammatory effect using the egg albumin method. PHY (100 mg/kg) co-treated with ASA and/or Diclo-Na reduced paw edema better than PHY alone or NSAIDs individual groups. Computational study showed that PHY efficiently interacts with COX-1 and 2, NF-κB, and IL-1β. In conclusion, PHY exhibits anti-inflammatory activity, possibly via COX-1 and 2, NF-κB, and IL-1β dependent pathways.

Phytol, a Chlorophyll Component, Produces Antihyperalgesic, Anti-inflammatory, and Antiarthritic Effects: Possible NFκB Pathway Involvement and Reduced Levels of the Proinflammatory Cytokines TNF-α and IL-6

Phytol is a diterpene constituent of chlorophyll and has been shown to have several pharmacological properties, particularly in relation to the management of painful inflammatory diseases. Arthritis is one of the most common of these inflammatory diseases, mainly affecting the synovial membrane, cartilage, and bone in joints. Proinflammatory cytokines, such as TNF-α and IL-6, and the NFκB signaling pathway play a pivotal role in arthritis. However, as the mechanisms of action of phytol and its ability to reduce the levels of these cytokines are poorly understood, we decided to investigate its pharmacological effects using a mouse model of complete Freund's adjuvant (CFA)-induced arthritis. Our results showed that phytol was able to inhibit joint swelling and hyperalgesia throughout the whole treatment period. Moreover, phytol reduced myeloperoxidase (MPO) activity and proinflammatory cytokine release in synovial fluid and decreased IL-6 production as well as the COX-2 immunocontent in the spinal cord. It also downregulated the p38MAPK and NFκB signaling pathways. Therefore, our findings demonstrated that phytol can be an innovative antiarthritic agent due to its capacity to attenuate inflammatory reactions in joints and the spinal cord, mainly through the modulation of mediators that are key to the establishment of arthritic pain.

Phytol loaded PLGA nanoparticles regulate the expression of Alzheimer's related genes and neuronal apoptosis against amyloid-β induced toxicity in Neuro-2a cells and transgenic Caenorhabditis elegans

Amyloid β (Aβ) induced neurotoxicity has been postulated to initiate synaptic loss and subsequent neuronal degeneration in Alzheimer's disease (AD). The nanoparticles based drug carrier system is considered as a promising therapeutic strategy to combat this incurable disease. It was also found to inhibit cholinesterase activity and apoptosis mediated cell death in Neuro-2a cells. The in vivo study further revealed that the Phytol and Phytol-PLGA NPs (Poly Lactic-co-Glycolic Acid Nanoparticles) was found to increase the lifespan, chemotaxis behavior and decrease Aβ deposition & ROS (Reactive oxygen species) production in transgenic Caenorhabditis elegans models of AD (CL2006, CL4176). Phytol and Phytol-PLGA NPs treatment downregulated the expression of AD associated genes viz Aβ, ace-1 and hsp-4 and upregulated the gene involved in the longevity to nematodes (dnj-14) and it also reduced the expression of Aβ peptide at the protein level. Our results of in vitro and in vivo studies suggest that Phytol and Phytol-PLGA NPs hold promising neuroprotective efficacy and targets multiple neurotoxic mechanisms involved in the AD progression.

Phytol ameliorated benzo(a)pyrene induced lung carcinogenesis in Swiss albino mice via inhibition of oxidative stress and apoptosis

In the present study, the modulatory effect of phytol against benzo(a)pyrene [B(a)P] induced lung carcinogenesis was investigated in Swiss albino mice. During the experimental period, phytol treatment showed no adverse toxic effect and mortality to the experimental animals. Lung tumor was observed in B(a)P treated group and also in animals post-treated with low concentration (50 mg/kg) of phytol. No neoplastic changes were observed in the lung tissue of the animals treated with the maximum dose of phytol (100 mg/kg). An elevated level of antioxidant enzymes combined with macromolecular damage (lipid peroxidation, protein carbonyl content) was observed upon B(a)P treatment whereas, phytol restored the level of antioxidant enzymes which were comparable to the vehicle control group. Moreover, administration of B(a)P induced apoptosis, as observed by the highest expression of Bax, caspase-3, and caspase-9 proteins in lung tissue of B(a)P alone treated animals. However, phytol treatment reduced the expression of Bax, caspase-3, and caspase-9 protein and maintained the constant expression of anti-apoptotic protein Bcl-2. These observations positively reveal that phytol regulates the antioxidant enzymes and thereby protects the cells against B(a)P induced carcinogenesis without showing any adverse toxic effect to the animals.

Synergistic interaction of β-caryophyllene with aromadendrene oxide 2 and phytol induces apoptosis on skin epidermoid cancer cells

BACKGROUND

Pamburus missionis (Wight) Swingle (Rutaceae) is traditionally used in the treatment of swellings, chronic rheumatism, paralysis and puerperal diseases. In a previous study the authors demonstrated apoptotic activity of Pamburus missionis essential oil (EO) on A431 and HaCaT cells. The major components of EO were β-caryophyllene (25.40%), 4(14),11- eudesmadiene (7.17%), aromadendrene oxide 2 (14.01%) (AO-(2) and phytol (6.88%).

PURPOSE OF STUDY

To investigate the role as well as the interactions among EO components inducing apoptosis in A431 and HaCaT cells.

METHODS

Isobolographic analysis and combination index methods were used to detect the type of interactions among the essential oil (EO) components. Cell viability was used to detect cytotoxic activity. Mechanism of cell death was studied using Annexin V-FITC/PI binding assay, cell cycle analysis, measurement of MMP and ROS generation by flow cytometry. Expression of apoptosis associated proteins was investigated by western blot.

RESULTS

Combination of P. missionis EO components: β-caryophyllene/ aromadendrene oxide 2 (β-C/AO-(2)), β-caryophyllene/phytol (β-C/P) and aromadendrene oxide 2 /phytol (AO-(2)/P) inhibited growth and colony formation ability of skin epidermoid A431 and precancerous HaCaT cells. Synergistic interaction was observed between β-C/AO-(2) and β-C/P combination while AO-(2)/P exhibited an additive effect. Combination of components induced chromatin condensation, phosphatidylserine externalisation, increase in sub-G1 DNA content, cell cycle arrest at G0/G1 phase and intracellular ROS accumulation. Inhibition of intracellular ROS by N-acetyl cysteine treatment blocked apoptosis induced by the combinations. The combinations induced apoptosis in A431 and HaCaT cells mediated by loss of mitochondrial membrane potential (ΔΨm), increase in Bax/Bcl-2 ratio, release of cytosolic cytochrome c and activation of caspases (cleaved form of caspase-3, caspase-8, caspase-9) and by PARP cleavage.

CONCLUSION

The present study demonstrates interactions among β-C, AO-(2) and P in the induction of apoptosis on A431 and HaCaT cells. These data suggest the combination of β-caryophyllene with aromadendrene oxide 2 and phytol could be potential therapeutics for the treatment of skin epidermoid cancer and precancerous cells.

Phytol-induced pathology in 2-hydroxyacyl-CoA lyase (HACL1) deficient mice. Evidence for a second non-HACL1-related lyase

2-Hydroxyacyl-CoA lyase (HACL1) is a key enzyme of the peroxisomal α-oxidation of phytanic acid. To better understand its role in health and disease, a mouse model lacking HACL1 was investigated. Under normal conditions, these mice did not display a particular phenotype. However, upon dietary administration of phytol, phytanic acid accumulated in tissues, mainly in liver and serum of KO mice. As a consequence of phytanic acid (or a metabolite) toxicity, KO mice displayed a significant weight loss, absence of abdominal white adipose tissue, enlarged and mottled liver and reduced hepatic glycogen and triglycerides. In addition, hepatic PPARα was activated. The central nervous system of the phytol-treated mice was apparently not affected. In addition, 2OH-FA did not accumulate in the central nervous system of HACL1 deficient mice, likely due to the presence in the endoplasmic reticulum of an alternate HACL1-unrelated lyase. The latter may serve as a backup system in certain tissues and account for the formation of pristanic acid in the phytol-fed KO mice. As the degradation of pristanic acid is also impaired, both phytanoyl- and pristanoyl-CoA levels are increased in liver, and the ω-oxidized metabolites are excreted in urine. In conclusion, HACL1 deficiency is not associated with a severe phenotype, but in combination with phytanic acid intake, the normal situation in man, it might present with phytanic acid elevation and resemble a Refsum like disorder.

Effect of Fabp1/Scp-2/Scp-x Ablation on Whole Body and Hepatic Phenotype of Phytol-Fed Male Mice

Liver fatty acid binding protein (Fabp1) and sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) genes encode proteins that enhance hepatic uptake, cytosolic transport, and peroxisomal oxidation of toxic branched-chain fatty acids derived from dietary phytol. Since male wild-type (WT) mice express markedly higher levels of these proteins than females, the impact of ablating both genes (TKO) was examined in phytol-fed males. In WT males, high phytol diet alone had little impact on whole body weight and did not alter the proportion of lean tissue mass (LTM) versus fat tissue mass (FTM). TKO conferred on dietary phytol the ability to induce weight loss as well as reduce liver weight, FTM, and even more so LTM. Concomitantly TKO induced hepatic lipid accumulation, preferentially threefold increased phospholipid (PL) at the expense of decreased triacylglycerol (TG) and total cholesterol. Increased PL was associated with upregulation of membrane fatty acid transport/translocase proteins (FATP 2,4), cytosolic fatty acid/fatty acyl-CoA binding proteins (FABP2, ACBP), and the rate limiting enzyme in PL synthesis (Gpam). Decreased TG and cholesterol levels were not attributable to altered levels in respective synthetic enzymes or nuclear receptors. These data suggest that the higher level of Fabp1 and Scp2/Scpx gene products in WT males was protective against deleterious effects of dietary phytol, but TKO significantly exacerbated phytol effects in males.

Piper betle and its bioactive metabolite phytol mitigates quorum sensing mediated virulence factors and biofilm of nosocomial pathogen Serratia marcescens in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Piper betle, a tropical creeper plant belongs to the family Piperaceae. The leaves of this plant have been well known for their therapeutic, religious and ceremonial value in South and Southeast Asia. It has also been reported to possess several biological activities including antimicrobial, antioxidant, antinociceptive, antidiabetic, insecticidal and gastroprotective activities and used as a common ingredient in indigenous medicines. In Indian system of ayurvedic medicine, P. betle has been well recognized for its antiseptic properties and is commonly applied on wounds and lesions for its healing effects.

AIM OF THE STUDY

To evaluate the anti-quorum sensing (anti-QS) and antibiofilm efficacy of P. betle and its bioactive metabolite phytol against Serratia marcescens.

MATERIALS AND METHODS

The P. betle ethyl acetate extract (PBE) was evaluated for its anti-QS efficacy against S. marcescens by assessing the prodigiosin and lipase production at 400 and 500µgml^-1 concentrations. In addition, the biofilm biomass quantification assay was performed to evaluate the antibiofilm activity of PBE against S. marcescens. Besides, the influence of PBE on bacterial biofilm formation was assessed through microscopic techniques. The biofilm related phenomenons like exopolysaccharides (EPS) production, hydrophobicity and swarming motility were also examined to support the antibiofilm activity of PBE. Transcriptional analysis of QS regulated genes in S. marcescens was also done. Characterization of PBE was done by separation through column chromatography and identification of active metabolites by gas chromatography -mass spectrometry. The major compounds of active fractions such as hexadecanoic acid, eugenol and phytol were assessed for their anti-QS activity against S. marcescens. Further, the in vitro bioassays such as protease, biofilm and HI quantification were also carried out to confirm the anti-QS and antibiofilm potential of phytol in PBE.

RESULTS

PBE inhibits QS mediated prodigiosin pigment production in S. marcescens, which confirmed its anti-QS potential against S. marcescens. At 500µgml^-1 concentration, PBE significantly inhibited the production of protease, lipase, biofilm and EPS to the level of 71%, 68%, 65% and 43% in S. marcescens, respectively. Further, their antibiofilm efficacy was confirmed through microscopic techniques. In addition, PBE effectively inhibited the hydrophobicity and swarming motility. Additionally, the results of qPCR analysis validated the downregulation of QS genes. Chromatographic techniques the presence of hexadecanoic acid, eugenol and phytol in PBE and the potential bioactive compound with anti-QS activity was identified as phytol. In vitro assays with phytol evidenced the potent inhibition of QS-controlled prodigiosin, protease, biofilm and hydrophobicity in S. marcescens, without exerting any deleterious effect on its growth.

CONCLUSION

This study demonstrates the promising anti-QS and antibiofilm activities of PBE and its active metabolite phytol, and confirms the ethnopharmacological applications of these leaves against S. marcescens infections.

Isolation and Identification of Mosquito (Aedes aegypti) Biting-Deterrent Compounds from the Native American Ethnobotanical Remedy Plant Hierochloë odorata (Sweetgrass)

Hierochloë odorata (L.) P. Beauv. (Poaceae), commonly known as sweetgrass, has documented use as an insect repellent by the Flatheads of Montana and Blackfoot of Alberta. Both the Flatheads of Montana and Blackfoot of Alberta would use braided plant material in a sachet in clothing or burn them from one end as incense, air/clothing freshener, and insect repellent. This study evaluated the insect-repellent properties of this plant using an in vitro mosquito Aedes aegypti feeding bioassay-directed approach to identify the compound(s) responsible for the observed activities. Evaluation of crude extracts produced from H. odorata revealed that the hydrodistillate had the highest level of mosquito biting deterrence. Fractionation of this extract, followed by re-evaluation for mosquito biting deterrence, produced many active fractions, which were evaluated by spectroscopic techniques and determined to contain phytol, coumarin, and 2-methoxy-4-vinylphenol. Phytol and coumarin were both determined to be responsible for the Ae. aegypti biting deterrency. Scientific evidence reported here validates its traditional use as a biting-insect deterrent.

Neuroprotective effect of the marine macroalga Gelidiella acerosa: identification of active compounds through bioactivity-guided fractionation

Context Gelidiella acerosa (Forsskål) Feldmann & G. Hamel (Rhodophyta-Gelidiales) is a marine red macroalga. Our previous work found that a benzene extract of G. acerosa possesses noticeable neuroprotective activity, when evaluated through in vitro and in vivo systems. Objective Bioactive-guided fractionation and identification of active compounds by column chromatography using solvents of varying polarity. Materials and methods Fractionation was done by column chromatography, antioxidant and anticholinesterase activity was assessed by DPPH and cholinesterase inhibition assays (50-200 μg/ml), compound identification was done by LC-MS analysis, the mode of interaction of active compound was analyzed through docking studies and quantification was done by high-performance thin-layer chromatography (HPTLC) analysis. Results The results suggest that fractions F9-F13 exhibited significant (p < 0.05) antioxidant and anticholinesterase activities. Hence, these fractions were pooled together and verified for neuroprotective activity. The pooled fraction was subjected to LC-MS analysis and among all the compounds, phytol was previously reported to possess excellent neuroprotective potential. Hence, the neuroprotective potential of phytol was assessed. The results suggest that phytol showed significant (p < 0.05) antioxidant activities (25-125 μg/ml) with an IC50 value of 95.27 ± 1.65 μg/ml and cholinesterase inhibitory potential (5-25 μg/ml) with IC50 values of 2.704 ± 0.07 and 5.798 ± 0.72 μg/ml for AChE and BuChE, respectively. Molecular docking studies suggest that phytol interacts with cholinesterase through the arginine residue of the enzyme. HPTLC quantification showed that about 6.266 μg of phytol was present per mg of pooled fraction. Conclusion The study suggests that phytol might act as the key compound in contributing to the neuroprotective potential of G. acerosa.

Essential Oil Variation from Twenty Two Genotypes of Citrus in Brazil-Chemometric Approach and Repellency Against Diaphorina citri Kuwayama

The chemical composition of volatile oils from 22 genotypes of Citrus and related genera was poorly differentiated, but chemometric techniques have clarified the relationships between the 22 genotypes, and allowed us to understand their resistance to D. citri. The most convincing similarities include the synthesis of (Z)-β-ocimene and (E)-caryophyllene for all 11 genotypes of group A. Genotypes of group B are not uniformly characterized by essential oil compounds. When stimulated with odor sources of 22 genotypes in a Y-tube olfactometer D. citri preferentially entered the arm containing the volatile oils of Murraya paniculata, confirming orange jasmine as its best host. C. reticulata × C. sinensis was the least preferred genotype, and is characterized by the presence of phytol, (Z)-β-ocimene, and β-elemene, which were not found in the most preferred genotype. We speculate that these three compounds may act as a repellent, making these oils less attractive to D. citri.

Acute toxicity, antiedematogenic activity, and chemical constituents of Palicourea rigida Kunth

The phytochemical study of the leaves, roots, and flowers of Palicourea rigida led to the isolation of the triterpenes betulinic acid (1) and lupeol (2), the diterpene phytol (3), and the iridoid glycosides sweroside (4) and secoxyloganin (5). These compounds were identified using NMR 1H and 13C and comparing the spectra with published data. We studied the antiedematogenic activity of crude extracts from the organs, and of different fractions, in mice and found that the n-hexane fraction of the leaf extract significantly inhibited the ear edema resulting from croton oil administration. The crude extract from leaves was not acutely toxic to the mice.

Activity against microorganisms affecting cellulosic objects of the volatile constituents of Leonotis nepetaefolia from Nicaragua

The chemical composition of the essential oil from aerial parts of L. nepetaefolia (L.) R. Br. collected in Nicaragua was evaluated by GC and GC-MS. The main components were (Z)-phytol (22.8%), caryophyllene oxide (18.9%) and hexahydrofarnesylacetone (9.0%). The antibacterial activity against several Gram + and Gram - bacteria, including Bacillus cereus and B. subtilis, both infesting historical cellulosic material, was also determined. B. cereus, B. subtilis and Staphylococcus epidermis were the most affected by the action of the oil.

Block of the mevalonate pathway triggers oxidative and inflammatory molecular mechanisms modulated by exogenous isoprenoid compounds

Deregulation of the mevalonate pathway is known to be involved in a number of diseases that exhibit a systemic inflammatory phenotype and often neurological involvements, as seen in patients suffering from a rare disease called mevalonate kinase deficiency (MKD). One of the molecular mechanisms underlying this pathology could depend on the shortage of isoprenoid compounds and the subsequent mitochondrial damage, leading to oxidative stress and pro-inflammatory cytokines’ release. Moreover, it has been demonstrated that cellular death results from the balance between apoptosis and pyroptosis, both driven by mitochondrial damage and the molecular platform inflammasome. In order to rescue the deregulated pathway and decrease inflammatory markers, exogenous isoprenoid compounds were administered to a biochemical model of MKD obtained treating a murine monocytic cell line with a compound able to block the mevalonate pathway, plus an inflammatory stimulus. Our results show that isoprenoids acted in different ways, mainly increasing the expression of the evaluated markers [apoptosis, mitochondrial dysfunction, nucleotide-binding oligomerization-domain protein-like receptors 3 (NALP3), cytokines and nitric oxide (NO)]. Our findings confirm the hypothesis that inflammation is triggered, at least partially, by the shortage of isoprenoids. Moreover, although further studies are necessary, the achieved results suggest a possible role for exogenous isoprenoids in the treatment of MKD.

Phytol a Natural Diterpenoid with Pharmacological Applications on Central Nervous System: A Review

Phytol (3,7,11,15-tetramethylhexadec-2-en-1-ol), a diterpene member of long and ramified chain of unsaturated acyclic alcohols. The objective of study was to conduct a systematic review of this diterpene and its pharmaceutical applications in Nervous System diseases in humans and/or rodents. Periodicals bases, such as ScienceDirect and PubMed, were used, as well as technological basis of European Patent Office, World Intellectual Property Organization, United States Patent and Trademark Office, Derwent Innovations Index(®), Latin American Bank of Patents and data base of Instituto Nacional de Propriedade Industrial (INPI-National Institute of Industrial Property). The software EndNote-X5 was utilized as reference with the keywords: phytol, anxiolytic, antidepressant and anticonvulsant and their correlations in English, Spanish and Portuguese from January 2003 to June 2014. There are many publications on phytol in international literature. However, there is a reduced number of articles related to pharmacological activities proposed here. In reference to technological bases, patents present a wide range of pharmacological and commercial applications as cosmetics, hypolipodemic, anxiolytic and antidepressant. Therefore, it is necessary to explore phytol molecules, which present high pharmacological potential from scientific and technological points of view, in search of transference of technologies to generate economical and industrial growth.

Terpene alcohols inhibit de novo sphingolipid biosynthesis

The terpene alcohols geranyllinalool, phytol (diterpene alcohol), and farnesol (sesquiterpene alcohol) were newly found to inhibit sphingolipid de novo biosynthesis in LLC-PK₁ cells (pig kidney epithelial cells). A simple chromatographic bioassay was established for the screening of inhibitory compounds able to reduce the amount of sphinganine, an intermediate metabolite of sphingolipid biosynthesis. The screening strategy was based on the degree of suppression of fumonisin B₁ (FB₁-induced sphinganine accumulation following co-treatment with selected terpene alcohols. L-cycloserine and ISP-1, specific serine palmitoyltransferase (SPT) inhibitors, were used as positive controls. Our results show that measuring reduced sphinganine levels after treatment with 2 µM FB₁ in combination with the putative inhibitory compounds provides a useful screening bioassay for evaluating compounds causing sphingolipid depletion. Intracellular sphinganine concentrations were analyzed using the fluorescent peak areas of the O-phthalaldehyde (OPA) derivatives of sphinganine eluted with 87 % acetonitrile on a reversed-phase column. Geranyllinalool, phytol, and farnesol were identified as novel SPT inhibitors that reduce FB₁-induced sphinganine accumulation and thus inhibit the first step of sphingolipid de novo synthesis.

Anti-scratching behavioral effect of the essential oil and phytol isolated from Artemisia princeps Pamp. in mice

The anti-scratching behavioral effect of the essential oil and phytol isolated from Artemisia princeps Pamp. (AP, family Asteraceae), which is widely used in traditional medicine for inflammatory diseases, was investigated IN VIVO. Treatment of mice with AP essential oil (APEO) and phytol inhibited histamine- and compound 48/80-induced scratching behaviors. The anti-scratching behavioral effects of APEO and phytol are in proportion to their vascular permeability-inhibitory effects. These agents also inhibited the level of allergic cytokines, IL-4, and TNF- α, and the activation of transcription factors, NF- κB and c-jun (AP-1), in histamine-treated skin tissues. Based on these results, APEO and phytol may improve scratching behavior in skin by inhibiting the expression of allergic cytokines via the regulation of NF- κB and AP-1 activation.

Aphrodisiac pheromones from the wings of the small cabbage white and large cabbage white butterflies, Pieris rapae and Pieris brassicae

The small and large cabbage butterflies, Pieris rapae and P. brassicae, are found worldwide and are of considerable economic importance. The composition of the male scent-producing organs present on the wings was investigated. More than 120 components were identified, but only a small portion proved to be male specific. Major components were the known beetle pheromone ferrulactone (1) in P. rapae and its previously unknown larger analogue, brassicalactone (2), in P. brassicae. The latter carries an additional isoprene unit and is closely related to 1. Other components present in larger amounts on male relative to female wings were hexahydrofarnesylacetone (18) and phytol (23). Brassicalactone (2) was fully characterized by synthesis of its various diastereomers by using ring-closing metathesis. A similar approach to ferrulactone (1) failed, presumably because of its smaller ring size. Instead, this compound was synthesized by using a modified literature procedure. The biological activity of the compounds in the extract was tested by coupled gas chromatographic-electroantennographic (GC-EAD) analysis, which showed that both macrolides and the other major components of the wings can be detected by the antennae of the conspecific female butterflies. Other detectable compounds included several alkanes, which are typical constituents of the butterfly cuticula, derivatives of phytol (23) and long-chain secondary alcohols. Finally, bioassays with males showed that the mixture of 1 (P. rapae) or 2 (P. brassicae) together with 18 and 23 applied to freshly eclosed males increased mating success compared to untreated males. Therefore, the two macrolides 1 and 2 are aphrodisiac pheromone components of male small and large cabbage white butterflies, respectively.

[Studies on chemical constituents of Laurencia tristicha ( II )]

OBJECTIVE

To search for chemical constituents with structural diversity from Laurencia tristicha to supply for biological assay.

METHOD

Compounds were isolated by means of column chromatography over normal phase silica gel and Sephadex LH-20, recrystallization and HPLC. Structures were identified by spectroscopic methods including 1D NMR, IR and MS. Cytotoxicities of the purified compounds were evaluated by MTT method.

RESULT

Seven compounds were isolated from L. tristicha. Their structures were elucidated as cholesterol (1), cholesta- 5-en-3beta, 7alpha-diol (2), beta-stigmasterol (3), phytol (4), zeaxanthin (5), 4 -hydroxybenzaldehyde (6), indolyl-3-carbaldehyde (7). In the cytotoxic assay compound 2 was active against human cancer cell lines HCT-8, Bel-7402, BGc-823, A549 and HELA with IC50 values of 1.90, 2.02, 1.99, 6.52 and 1.20 microg x mL(-1), respectively. Compound 4 showed cytotoxicity against HCT-8 and HELA with IC50 value of 3.51 and 2.04 microg x mL(-1), and other compounds were inactive ( IC50 > 10 microg x mL(-1)).

CONCLUSION

Compounds 1-7 were isolated from L. tristicha for the first time. In additon, compounds 2 and 4 were cytotoxic against several human cancer cell lines.

Dual subcellular localization in the endoplasmic reticulum and peroxisomes and a vital role in protecting against oxidative stress of fatty aldehyde dehydrogenase are achieved by alternative splicing

Fatty aldehyde dehydrogenase (FALDH, ALDH3A2) is thought to be involved in the degradation of phytanic acid, a saturated branched chain fatty acid derived from chlorophyll. However, the identity, subcellular distribution, and physiological roles of FALDH are unclear because several variants produced by alternative splicing are present in varying amounts at different subcellular locations. Subcellular fractionation experiments do not provide a clear-cut conclusion because of the incomplete separation of organelles. We established human cell lines heterologously expressing mouse FALDH from each cDNA without tagging under the control of an inducible promoter and detected the variant FALDH proteins using a mouse FALDH-specific antibody. One variant, FALDH-V, was exclusively detected in peroxisomal membranes. Human FALDH-V with an amino-terminal Myc sequence also localized to peroxisomes. The most dominant form, FALDH-N, and other variants examined, however, were distributed in the endoplasmic reticulum. A gas chromatography-mass spectrometry-based analysis of metabolites in FALDH-expressing cells incubated with phytol or phytanic acid showed that FALDH-V, not FALDH-N, is the key aldehyde dehydrogenase in the degradation pathway and that it protects peroxisomes from oxidative stress. In contrast, both FALDHs had a protective effect against oxidative stress induced by a model aldehyde for lipid peroxidation, dodecanal. These results suggest that FALDH variants are produced by alternative splicing and share an important role in protecting against oxidative stress in an organelle-specific manner.

Arthritis suppression by NADPH activation operates through an interferon-beta pathway

BACKGROUND

A polymorphism in the activating component of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex, neutrophil cytosolic factor 1 (NCF1), has previously been identified as a regulator of arthritis severity in mice and rats. This discovery resulted in a search for NADPH oxidase-activating substances as a potential new approach to treat autoimmune disorders such as rheumatoid arthritis (RA). We have recently shown that compounds inducing NCF1-dependent oxidative burst, e.g. phytol, have a strong ameliorating effect on arthritis in rats. However, the underlying molecular mechanism is still not clearly understood. The aim of this study was to use gene-expression profiling to understand the protective effect against arthritis of activation of NADPH oxidase in the immune system.

RESULTS

Subcutaneous administration of phytol leads to an accumulation of the compound in the inguinal lymph nodes, with peak levels being reached approximately 10 days after administration. Hence, global gene-expression profiling on inguinal lymph nodes was performed 10 days after the induction of pristane-induced arthritis (PIA) and phytol administration. The differentially expressed genes could be divided into two pathways, consisting of genes regulated by different interferons. IFN-gamma regulated the pathway associated with arthritis development, whereas IFN-beta regulated the pathway associated with disease protection through phytol. Importantly, these two molecular pathways were also confirmed to differentiate between the arthritis-susceptible dark agouti (DA) rat, (with an Ncf-1DA allele that allows only low oxidative burst), and the arthritis-protected DA.Ncf-1E3 rat (with an Ncf1E3 allele that allows a stronger oxidative burst).

CONCLUSION

Naturally occurring genetic polymorphisms in the Ncf-1 gene modulate the activity of the NADPH oxidase complex, which strongly regulates the severity of arthritis. We now show that the Ncf-1 allele that enhances oxidative burst and protects against arthritis is operating through an IFN-beta-associated pathway, whereas the arthritis-driving allele operates through an IFN-gamma-associated pathway. Treatment of arthritis-susceptible rats with an NADPH oxidase-activating substance, phytol, protects against arthritis. Interestingly, the treatment led to a restoration of the oxidative-burst effect and induction of a strikingly similar IFN-beta-dependent pathway, as seen with the disease-protective Ncf1 polymorphism.

Effect of SCP-x gene ablation on branched-chain fatty acid metabolism

Despite the importance of peroxisomal oxidation in branched-chain lipid (phytol, cholesterol) detoxification, little is known regarding the factors regulating the peroxisomal uptake, targeting, and metabolism of these lipids. Although in vitro data suggest that sterol carrier protein (SCP)-x plays an important role in branched-chain lipid oxidation, the full physiological significance of this peroxisomal enzyme is not completely clear. To begin to resolve this issue, SCP-x-null mice were generated by gene ablation of SCP-x from the SCP-x/SCP-2 gene and fed a phytol-enriched diet to characterize the effects of lipid overload in a system with minimal 2/3-oxoacyl-CoA thiolytic activity. It was shown that SCP-x gene ablation 1) did not result in reduced expression of SCP-2 (previously thought to be derived in considerable part by posttranslational cleavage of SCP-x); 2) increased expression levels of key enzymes involved in alpha- and beta-oxidation; and 3) altered lipid distributions, leading to decreased hepatic fatty acid and triglyceride levels. In response to dietary phytol, lack of SCP-x resulted in 1) accumulation of phytol metabolites despite substantial upregulation of hepatic peroxisomal and mitochondrial enzymes; 2) reduced body weight gain and fat tissue mass; and 3) hepatic enlargement, increased mottling, and necrosis. In summary, the present work with SCP-x gene-ablated mice demonstrates, for the first time, a direct physiological relationship between lack of SCP-x and decreased ability to metabolize branched-chain lipids.

[Chemical constituents from red alga Corallina pilulifera]

OBJECTIVE

To investigate the chemical constituents of red alga Corallina pilulifera.

METHOD

Compounds were isolated by normal phase silica gel and Sephadex LH - 20 gel column chromatography, reverse phase HPLC and recrystallization. Their structures were elucidated by spectroscopic methods including MS, 1H-NMR, 13C-NMR, HSQC, HMBC. Cytotoxicity of the compounds was screened by using standard MTT method.

RESULT

Seven compounds were isolated from red alga C. pilulifera, their structures were identified as (E) -phytol epoxide (1), phytenal (2), phytol (3), dehydrovomifoliol (4), loliolide (5), 3beta-hydroxy-5alpha, 6alpha-epoxy-7-megastigmene-9-one (6), 4-hydroxybenzaldehyde (7).

CONCLUSION

All of the compounds were obtained from this species for the first time. These compounds were inactive (IC50 > 10 microg x mL(-1)) in the MTT assay.

Evidence for the preventive effect of the polyunsaturated phytol side chain in tocotrienols on 17beta-estradiol epoxidation

BACKGROUND

We found that 17beta-estradiol (E2) could be activated by epoxidation to bind DNA and to inhibit nuclear RNA synthesis. Vitamin E compounds are powerful antioxidants and chain-breaking free radical scavengers. The chromanol ring in Vitamin E is believed to be involved in these reactions.

METHODS

Here, we examined the preventive effect of alpha-tocopherol, alpha-, gamma- and delta-tocotrienols on E2 activation.

RESULTS

We found that when any one of these Vitamin E compounds was mixed with E2 for epoxidation by the epoxide-forming oxidant dimethyldioxirane (DMDO), alpha-tocopherol was the least effective as compared with the tocotrienols against the formation of E2 epoxide as reflected by the loss of the ability of E2 to inhibit nuclear RNA synthesis. This conclusion was further confirmed by the binding studies of [3H] labeled E2 to DNA using either DMDO or liver microsomes activation system.

CONCLUSIONS

Since the chromanol ring is shared by both tocopherols and tocotrienols and the only difference between these two subgroups of Vitamin E is the phytol side chain, we conclude that the polyunsaturated phytol group in tocotrienols plays a key preventive role in E2 epoxidation. This is the first report showing that the polyunsaturated phytol side chain in tocotrienols is involved in an antioxidative activity and it may also have a preventive effect against the E2 epoxide induced breast cancer carcinogenesis at the initiation.

A pharmacological action of vitamin E unrelated to its antioxidant capacity

The pharmacological action of vitamin E on the mechanical activity of isolated guinea pig colonic smooth muscle was examined in normoxic and hypoxic conditions. In hypoxia, but not normoxia, alpha-tocopherol (1-160 microM) evoked rapid concentration-dependent contractions from the colon. This was also seen with other members of the vitamin E family, and potency measurements gave EC(50) values (microM) of 10.6 +/- 0.9 for D-alpha-tocopherol, 6.0 +/- 1.2 for D-beta-tocopherol, 7.5 +/- 0.7 for D-gamma-tocopherol, and 6.1 +/- 1.5 for D-delta-tocopherol. This order of potency for the components of the vitamin differs from previously studied bioassay systems and from their antioxidant activity. A range of potent natural and synthetic antioxidants was not active in this system. Compounds with structural similarities to the side chain of vitamin E produced similar stimulatory responses and some, like phytol, were more potent than the vitamin (EC(50): 1.0 +/- 0.2 microM), whereas ring structures related to the vitamin, like Trolox C, antagonized the stimulant responses in a concentration-dependent manner. Therefore, this model system measures, directly, vitamin E-induced responses through a mechanism that does not appear to be related to the known antioxidant capacity of these agents.

Ovipositional deterrent on mature stage of sweet pepper, Capsicum annuum, against Liriomyza trifolii (Burgess)

Liriomyza trifolii (Burgess), the American serpentine leafminer fly, is a well-known serious pest in the world. This insect species attacks plants of more than 21 families including Solanaceae plants. A sweet pepper, Capsicum annuum (Solanaceae), on mature stage, however, shows resistance to this leafminer fly. This resistance is based on the ovipositional deterrent in the sweet pepper leaf against the fly species. Based on the bioassay guided fractionation, phytol [(2E)-3,7,11,15-tetramethyl-2-hexadecen-1-ol] was isolated and identified as an ovipositional deterrent against this insect species. The yield of this compound was 815 microg/g fresh leaf of C. annuum. This compound completely deterred the females from laying their eggs on host plant leaves treated at 35.2 microg/cm2.

Phytol directly activates peroxisome proliferator-activated receptor α (PPARα) and regulates gene expression involved in lipid metabolism in PPARα-expressing HepG2 hepatocytes

The peroxisome proliferator-activated receptor (PPAR) is one of the indispensable transcription factors for regulating lipid metabolism in various tissues. In our screening for natural compounds that activate PPAR using luciferase assays, a branched-carbon-chain alcohol (a component of chlorophylls), phytol, has been identified as a PPARalpha-specific activator. Phytol induced the increase in PPARalpha-dependent luciferase activity and the degree of in vitro binding of a coactivator, SRC-1, to GST-PPARalpha. Moreover, the addition of phytol upregulated the expression of PPARalpha-target genes at both mRNA and protein levels in PPARalpha-expressing HepG2 hepatocytes. These findings indicate that phytol is functional as a PPARalpha ligand and that it stimulates the expression of PPARalpha-target genes in intact cells. Because PPARalpha activation enhances circulating lipid clearance, phytol may be important in managing abnormalities in lipid metabolism.

The screening of chemicals for juvenoid-related endocrine activity using the water flea Daphnia magna

U.S. Environmental Protection Agency is charged with developing a screening and testing paradigm for detecting endocrine toxicity of chemicals that are subject to regulation under the Food Quality Protection and the Safe Drinking Water Acts. In this study, we developed and evaluated a screening assay that could be employed to detect juvenoid-related endocrine-modulating activity in an invertebrate species. Juvenoid activity, anti-juvenoid activity, and juvenoid potentiator activity of chemicals was assessed using the water flea Daphnia magna. Male sex determination is under the regulatory control of juvenoid hormone, presumably methyl farnesoate, and this endpoint was used to detect juvenoid modulating activity of chemicals. Eighteen chemicals were evaluated for juvenoid agonist activity. Positive responses were detected with the juvenoid hormones methyl farnesoate and juvenile hormone III along with the insect growth regulating insecticides pyriproxyfen, fenoxycarb, and methoprene. Weak juvenoid activity also was detected with the cyclodiene insecticide dieldrin. Assays performed repetitively with compounds that gave either strong positive, weak positive, or negative response were 100% consistent indicating that the assay is not prone to false positive or negative responses. Five candidate chemicals were evaluated for anti-juvenoid activity and none registered positive. Four chemicals (all trans-retinoic acid, methoprene, kinoprene, bisphenol A) also were evaluated for their ability to potentiate the activity of methyl farnesoate. All registered positive. Results demonstrate that an in vivo assay with a crustacean species customarily employed in toxicity testing can be used to effectively screen chemicals for juvenoid-modulating activity.

Biphasic effects of geranylgeraniol, teprenone, and phytol on the growth of Staphylococcus aureus

We examined the antibacterial activities against Staphylococcus aureus of three diterpenes, namely, geranylgeraniol, teprenone, and phytol, by using a broth dilution with shaking method to identify the effects of diterpenes with long aliphatic carbon chains. We also performed time-kill assays and measured the leakage of K(+) ions from bacterial cells in response to these diterpenes. The diterpenes used inhibited the growth of S. aureus at concentrations of 0.15 microg/ml, as determined by damage to the cell membranes, and had clear bactericidal activity. However, the inhibitory effects of the diterpenes decreased when the concentration of each was raised above a certain level. The diterpenes tested in this study appeared to have both growth-inhibitory and growth-accelerating effects, and the net effect of each depended on its concentration.

A phytol-enriched diet induces changes in fatty acid metabolism in mice both via PPARalpha-dependent and -independent pathways

Branched-chain fatty acids (such as phytanic and pristanic acid) are ligands for the nuclear hormone receptor peroxisome proliferator-activated receptor alpha (PPARalpha) in vitro. To investigate the effects of these physiological compounds in vivo, wild-type and PPARalpha-deficient (PPARalpha-/-) mice were fed a phytol-enriched diet. This resulted in increased plasma and liver levels of the phytol metabolites phytanic and pristanic acid. In wild-type mice, plasma fatty acid levels decreased after phytol feeding, whereas in PPARalpha-/- mice, the already elevated fatty acid levels increased. In addition, PPARalpha-/- mice were found to be carnitine deficient in both plasma and liver. Dietary phytol increased liver free carnitine in wild-type animals but not in PPARalpha-/- mice. Investigation of carnitine biosynthesis revealed that PPARalpha is likely involved in the regulation of carnitine homeostasis. Furthermore, phytol feeding resulted in a PPARalpha-dependent induction of various peroxisomal and mitochondrial beta-oxidation enzymes. In addition, a PPARalpha-independent induction of catalase, phytanoyl-CoA hydroxylase, carnitine octanoyltransferase, peroxisomal 3-ketoacyl-CoA thiolase, and straight-chain acyl-CoA oxidase was observed. In conclusion, branched-chain fatty acids are physiologically relevant ligands of PPARalpha in mice. These findings are especially relevant for disorders in which branched-chain fatty acids accumulate, such as Refsum disease and peroxisome biogenesis disorders.

A mouse model for α-methylacyl-CoA racemase deficiency: adjustment of bile acid synthesis and intolerance to dietary methyl-branched lipids

alpha-Methylacyl-CoA racemase (Amacr) deficiency in humans leads to sensory motor neuronal and liver abnormalities. The disorder is recessively inherited and caused by mutations in the AMACR gene, which encodes Amacr, an enzyme presumed to be essential for bile acid synthesis and to participate in the degradation of methyl-branched fatty acids. To generate a model to study the pathophysiology in Amacr deficiency we inactivated the mouse Amacr gene. As per human Amacr deficiency, the Amacr(-/-) mice showed accumulation (44-fold) of C27 bile acid precursors and decreased (over 50%) primary (C24) bile acids in bile, serum and liver, however the Amacr(-/-) mice were clinically symptomless. Real-time quantitative PCR analysis showed that, among other responses, the level of mRNA for peroxisomal multifunctional enzyme type 1 (pMFE-1) was increased 3-fold in Amacr(-/-) mice. This enzyme can be placed, together with CYP3A11 and CYP46A1, to make an Amacr-independent pathway for the generation of C24 bile acids. Exposure of Amacr(-/-) mice to a diet supplemented with phytol, a source for branched-chain fatty acids, triggered the development of a disease state with liver manifestations, redefining the physiological significance of Amacr. Amacr is indispensable for the detoxification of dietary methyl-branched lipids and, although it contributes normally to bile acid synthesis from cholesterol, the putative pMFE-1-mediated cholesterol degradation can provide for generation of bile acids, allowing survival without Amacr. Based upon our mouse model, we propose elimination of phytol from the diet of patients suffering from Amacr deficiency.

Sexually dimorphic metabolism of branched-chain lipids in C57BL/6J mice

Despite the importance of branched chain lipid oxidation in detoxification, almost nothing is known regarding factors regulating peroxisomal uptake, targeting, and metabolism. One peroxisomal protein, sterol carrier protein-x (SCP-x), is thought to catalyze a key thiolytic step in branched chain lipid oxidation. When mice with substantially lower hepatic levels of SCP-x were tested for susceptibility to dietary stress with phytol (a phytanic acid precursor and peroxisome proliferator), livers of phytol-fed female but not male mice i). accumulated phytol metabolites (phytanic acid, pristanic acid, and Delta-2,3-pristanic acid); ii). exhibited decreased fat tissue mass and increased liver mass/body mass; iii). displayed signs of histopathological lesions in the liver; and iv). demonstrated significant alterations in hepatic lipid distributions. Moreover, both male and female mice exhibited phytol-induced peroxisomal proliferation, as demonstrated by liver morphology and upregulation of the peroxisomal protein catalase. In addition, levels of liver fatty acid binding protein, along with SCP-2 and SCP-x, increased, suggesting upregulation mediated by phytanic acid, a known ligand agonist of the peroxisomal proliferator-activated receptor alpha. In summary, the present work establishes a role for SCP-x in branched chain lipid catabolism and demonstrates a sexual dimorphic response to phytol, a precursor of phytanic acid, in lipid parameters and hepatotoxicity.

Methyl palmitate: a novel product of the Medfly (Ceratitis capitata) corpus allatum

The corpus allatum (CA) of adult female Ceratitis capitata produces methyl palmitate (MP) in vitro, in addition to JHB(3) and JH III. Biosynthesized MP migrates on TLC and co-elutes from RP-18 HPLC with synthetic MP. Its identity is verified herein by GCMS. MP production is up-regulated twofold by mevastatin, an inhibitor of mevalonic acid-dependent isoprene biosynthesis. Fosmidomycin, an inhibitor of mevalonic acid-independent isoprene synthesis in graminaceous plants, up-regulates MP synthesis by about fourfold. However, it does not depress JHB(3) biosynthesis concurrently. This suggests that the initial enzyme(s) in the conversion of 1-deoxy-xylulose 5-phosphate to isoprene is presumably present in C. capitata, but is inhibited by fosmidomycin, and this inhibition diverts precursors to MP synthesis. Phytol, an acyclic diterpene, might be suppressing isoprene biosynthesis by CA, thereby resulting in a fourfold increase in the MP biosynthesis. Linolenic acid is an end-product and its presence in incubation media up-regulates MP biosynthesis by twofold, presumably due to the feedback diversion to biosynthesis of C(16:0) and its methyl ester. Biosynthesis of MP is markedly depressed after mating, while otherwise maintained at significantly higher levels in virgin females. MP biosynthesis is significantly reduced in virgin females by direct axonal control but is less consistent after mating.

Menatetrenone (vitamin K2) acts directly on circulating human osteoclast precursors

It is still not certain what the direct effect of menatetrenone is on osteoclast precursors. In the present study, we investigated whether menatetrenone has a direct effect on circulating osteoclast precursors to influence osteoclast differentiation. Monocytes isolated from human peripheral blood were cultured with receptor-activated NF-kappaB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). Menatetrenone or vitamin K1 was then added to the cultures. Geranylgeraniol or phytol (the respective side chain) was also added to the cultures instead of menatetrenone or vitamin K1, respectively. After 7 and 14 days incubation, cultures were evaluated for cytochemical and functional evidence of osteoclast formation. The number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs) and the percentage area of lacunar resorption induced by RANKL and M-CSF were decreased when menatetrenone or geranylgeraniol was added to the cultures. Dose-dependent inhibition of osteoclast formation and lacunar resorption was seen when the cultures were treated with menatetrenone or geranylgeraniol. In contrast, vitamin K1 or phytol did not affect the number of TRAP-positive MNCs nor the percentage area of lacunar resorption. These results indicate that menatetrenone not only influences osteoclast formation via bone stromal cells but also acts directly on circulating osteoclast precursors to influence osteoclast differentiation. These findings also suggest that geranylgeraniol, the side chain of menatetrenone, plays an important role in this inhibitory effect.

Diol- and triol-types of phytol induce apoptosis in lymphoid leukemia Molt 4B cells

The exposure of human lymphoid leukemia Molt 4B cells to diol- and triol-types of phytol which were synthesized and identified by Mass, and 1H- and 13C-NMR, led to both growth inhibition and induction of programmed cell death (apoptosis). Morphological changes showing apoptotic bodies were observed in the Molt 4B cells treated with diol- and triol-types of phytol. The fragmentations of DNA by the diol- and triol-types of phytol to oligonucleosomal-sized fragments, that is a characteristic of apoptosis, were observed to be both concentration- and time-dependent. These findings suggest that growth inhibition of Molt 4B cells by the diol- and triol-types of phytol results from the induction of apoptosis in the leukemic cells.

Phytol, SSADH inhibitory diterpenoid of Lactuca sativa

The succinic semialdehyde dehydrogenase (SSADH) inhibitory component was isolated from the EtOAc fraction of Lactuca sativa through repeated column chromatography; then, it was identified as phytol, a diterpenoid, based on the interpretation of several spectral data. Incubation of SSADH with the phytol results in a time-dependent loss of enzymatic activity, suggesting that enzyme modification is irreversible. The inactivation followed pseudo-first-order kinetics with the second-rate order constant of 6.15 x 10(-2) mM(-1) min(-1). Complete protection from inactivation was afforded by the coenzyme NAD+, whereas substrate succinic semialdehyde failed to prevent the inactivation of the enzyme; therefore, it seems likely that phytol covalently binds at or near the active site of the enzyme. It is postulated that the phytol is able to elevate the neurotransmitter GABA levels in central nervous system through its inhibitory action on one of the GABA degradative enzymes, SSADH.

Phytanic acid, but not pristanic acid, mediates the positive effects of phytol derivatives on brown adipocyte differentiation

The phytol derivatives phytanic acid and pristanic acid may activate nuclear hormone receptors and influence gene expression and cell differentiation. Phytanic acid induces brown adipocyte differentiation. It was determined that brown fat and brown adipocytes are sites of high gene expression of phytanoyl-CoA hydroxylase, the enzyme required for initiation of peroxisomal alpha-oxidation of phytanic acid. However, the effects of phytanic acid were not mediated by its alpha-oxidation product pristanic acid, which did not promote brown adipocyte differentiation or stimulate transcription of the uncoupling protein-1 gene. Moreover, acute cold exposure of mice caused a dramatic mobilization of the phytanic acid stores in brown adipose tissue thus suggesting that a high local exposure to phytanic acid in brown fat may contribute to signalling adaptive changes in the tissue in response to thermogenic activation.

Prevention of vitamin A teratogenesis by phytol or phytanic acid results from reduced metabolism of retinol to the teratogenic metabolite, all-trans-retinoic acid

Previous studies in our laboratory showed a synergistic interaction of synthetic ligands selective for the retinoid receptors RAR and RXR in regard to teratogenic effects produced in mice (M. M. Elmazar et al., 2001, TOXICOL: Appl. Pharmacol. 170, 2-9). In the present study the influence of phytol and phytanic acid (a RXR-selective ligand) on the teratogenicity of retinol and the RAR-selective ligand all-trans-retinoic acid was investigated by coadministration experiments on day 8.25 of gestation in NMRI mice. Phytol and phytanic acid, noneffective when administered alone, did not potentiate the teratogenicity induced by retinol or all-trans-retinoic acid. On the contrary, phytol and phytanic acid greatly reduced retinol-induced teratogenic effects (ear anotia, tail defects, exencephaly). The effect of phytol on all-trans-retinoic acid teratogenesis was limited (only resorptions and tail defects were reduced). Pharmacokinetic studies in nonpregnant animals revealed that phytol coadministration with retinol reduced plasma levels of retinol and retinyl esters, and drastically reduced the levels of the teratogenic retinol metabolite, all-trans-retinoic acid. Phytanic acid also reduced the oxidative metabolism and teratogenic effects of retinol. These results indicate that phytol and phytanic acid did not synergize with retinol and all-trans-retinoic acid in our mouse teratogenesis model. Instead, phytol and phytanic acid effectively blocked the teratogenic effects of retinol by drastically reducing the metabolic production of all-trans-retinoic acid. Phytol and phytanic acid may be useful for the prevention of vitamin A teratogenicity.

Cytotoxic constituents from Solidago virga-aurea var. gigantea MIQ

Activity-guided fractionation of the whole plant of Solidago virga-aurea var. gigantea M(IQ). (Compositae) has led to the isolation of three cytotoxic compounds, erythrodiol-3-acetate (1), alpha-tocopherol-quinone (2), and trans-phytol (3) from the hexane soluble fraction. It is the first report of those compounds from the genus.

Phytol induces programmed cell death in human lymphoid leukemia Molt 4B cells

The exposure of human lymphoid leukemia Molt 4B cells to phytol which was isolated from Lolium multiflorum Lam and identified by MS, and 1H- and 13C-NMR, led to both growth inhibition and the induction of programmed cell death (apoptosis). Morphological change showing apoptotic bodies was observed in the cells treated with phytol. The fragmentation by phytol of DNA to oligonucleosomal-sized fragments that are characteristics of apoptosis was observed to be concentration- and time-dependent. These findings suggest that growth inhibition by phytol of Molt 4B cells results from the induction of apoptosis in the cells.

Phytanic acid is ligand and transcriptional activator of murine liver fatty acid binding protein

Branched-chain phytanic acid is metabolized in liver peroxisomes. Sterol carrier protein 2/sterol carrier protein x (SCP2/SCPx) knockout mice, which develop a phenotype with a deficiency in phytanic acid degradation, accumulate dramatically high concentrations of this fatty acid in serum (Seedorf at al. 1998. Genes Dev. 12: 1189-1201) and liver. Concomitantly, a 6.9-fold induction of liver fatty acid binding protein (L-FABP) expression is observed in comparison to wild-type animals fed standard chow, possibly mediated by the peroxisome proliferator-activated receptor alpha (PPARalpha). Cytosolic transport of phytanic acid to either peroxisomal membranes or to the nucleus for activation of PPARalpha may be mediated by L-FABP, which gives rise to the question whether phytanic acid is a transactivator of this protein. Here we show first that phytanic acid binds to recombinant L-FABP with high affinity. Then the increase of the in vivo phytanic acid concentration by phytol feeding to mice results in a 4-fold induction of L-FABP expression in liver, which is in the order of that attained with bezafibrate, a known peroxisome proliferator. Finally to test in vitro whether this induction is conferred by phytanic acid, we cotransfected HepG2 cells with an expression plasmid for murine PPARalpha and a CAT-reporter gene with 176 bp of the murine L-FABP promoter, containing the peroxisome proliferator responsive element (PPRE). After incubation with phytanic acid, we observed a 3.2-fold induction of CAT expression. These findings, both in vivo and in vitro, demonstrate that phytanic acid is a transcriptional activator of L-FABP expression and that this effect is mediated via PPARalpha.

Antimycobacterial activity of (E)-phytol and derivatives: a preliminary structure-activity study

The crude methanol extract of the Kenyan shrub Leucas volkensii Gürke (Labiatae) displayed in a radiorespirometric bioassay antimycobacterial activity against Mycobacterium tuberculosis. Bioassay-guided fractionation of the crude extract led to the identification of (E)-phytol as the principal active component with a minimum inhibitory concentration (MIC) of 2 micrograms/ml, a value also observed for (3R,S,7R,11R)-phytanol, (Z)-phytol, and a commercially available 2:1 mixture of (E)- and (Z)-phytol. The derivatives (E)-phytol acetate, a mixture of the (2S,3S)- and (2R,3R)-isomers of (E)-phytol epoxide and (3R,S,7R,11R)-phytanic acid displayed lower activities with MICs of 8, 16, and > 128 micrograms/ml, respectively. Geraniol and farnesol, displayed MICs of 64 and 8 micrograms/ml, respectively. The activities of (E)-phytol, (Z)-phytol and (3R,S,7R,11R)-phytanol were found to be in the same range as ethambutol, a clinically useful drug with an MIC in the range 0.95-3.8 micrograms/ml.

A succinylanthranilic acid ester and other bioactive constituents of Jolyna laminarioides

Methyl 2-[propanamide-2'-methoxycarbonyl] benzoate, fucosterol, trans-phytol and p-formylphenol were isolated for the first time from a methanolic extract of Jolyna laminarioides. Methyl 2-[propanamide-2'-methoxycarbonyl]-benzoate exhibited chymotrypsin inhibitory activity and also found to be active against Escherichia coli and Shigella boydii. Fucosterol exhibited antifungal activity against Curvularia lunata, Stachybotrys atra and Microsporum canis.