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1.
Naunyn Schmiedebergs Arch Pharmacol ; 397(7): 5131-5144, 2024 07.
Article in English | MEDLINE | ID: mdl-38240783

ABSTRACT

This study explored the potential of poly-(lactic-co-glycolic) acid (PLGA) nanoparticles to enhance the effectiveness of anticancer treatments through combination therapy with phytol and α-bisabolol. The encapsulation efficiency of the nanoparticles was investigated, highlighting the role of ionic interactions between the drugs and the polymer. Characterization of PLGA-Phy+Bis nanoparticles was carried out using DLS with zeta potential and HR-TEM for size determination. Spectrophotometric measurements evaluated the encapsulation efficiency, loading efficiency, and in vitro drug release. FTIR analysis assessed the chemical interactions between PLGA and the drug actives, ensuring nanoparticle stability. GC-MS was employed to analyze the chemical composition of drug-loaded PLGA nanocarriers. Cytotoxicity was evaluated via the MTT assay, while Annexin V-FITC/PI staining and western blot analysis confirmed apoptotic cell death. Additionally, toxicity tests were performed on L-132 cells and in vivo zebrafish embryos. The study demonstrates high encapsulation efficiency of PLGA-Phy+Bis nanoparticles, which exhibit monodispersity and sizes of 189.3±5nm (DLS) and 268±54 nm (HR-TEM). Spectrophotometric analysis confirmed efficient drug encapsulation and release control. FTIR analysis revealed nanoparticle structural stability without chemical interactions. MTT assay results demonstrated the promising anticancer potential of all the three nanoparticle types (PLGA-Phy, PLGA-Bis, and PLGA-Phy+Bis) against lung cancer cells. Apoptosis was confirmed through Annexin V-FITC/PI staining and western blot analysis, which also revealed changes in Bax and Bcl-2 protein expression. Furthermore, the nanoparticles exhibited non-toxicity in L-132 cells and zebrafish embryo toxicity tests. PLGA-Phy+Bis nanoparticles exhibited efficient encapsulation, controlled release, and low toxicity. Apoptosis induction in A549 cells and non-toxicity in healthy cells highlight their clinical potential.


Subject(s)
Apoptosis , Drug Synergism , Lung Neoplasms , Monocyclic Sesquiterpenes , Nanoparticles , Phytol , Polylactic Acid-Polyglycolic Acid Copolymer , Zebrafish , Apoptosis/drug effects , Animals , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Humans , Nanoparticles/chemistry , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Monocyclic Sesquiterpenes/pharmacology , Monocyclic Sesquiterpenes/administration & dosage , Phytol/administration & dosage , Phytol/pharmacology , Phytol/chemistry , Phytol/toxicity , Cell Line, Tumor , Drug Carriers/chemistry , A549 Cells , Drug Liberation , Sesquiterpenes/pharmacology , Sesquiterpenes/administration & dosage , Sesquiterpenes/chemistry , Sesquiterpenes/toxicity , Cell Survival/drug effects
2.
Inhal Toxicol ; 33(1): 33-40, 2021 01.
Article in English | MEDLINE | ID: mdl-33441006

ABSTRACT

Introduction: The use of vaping pens for inhalation of cannabinoid derived products is rising and has become a popular alternative to smoking combustible products. For efficient product delivery, additives are sometimes added and vaping pens often may include compounds like Phytol or Propylene Glycol as thinning agents. This study aimed at comparing Phytol and Propylene Glycol with respect to potential toxicity and safe use in vaping products.Methods: Male and female Sprague Dawley rats were exposed to 5 mg/L of Phytol or Propylene Glycol for up to 6 hours over up to 14 days and monitored for clinical signs and changes in body weight. Gross necropsy and histopathology of respiratory tissue was performed to assess potential adverse effects.Results: Phytol exposed animals expressed severe clinical signs, body weight loss and mortality after one or two exposure days, leading to termination of all dose groups for this compound. Lung weights were increased and respiratory tissue was severely affected, demonstrating dose-responsive tissue degeneration, necrosis, edema, hemorrhage and inflammation. Propylene Glycol exposed animals did not show any adverse reactions after 14 days of high dose exposure.Conclusions: For Phytol, a low observed adverse effect level (LOAEL) was determined at ≤109.0/10.9 mg/kg/day presented/deposited dose and therefore its use as excipient in vaping product is not recommend; a safe exposure range was not established for Phytol. Propylene Glycol, in contrast, is considered safe with a no observed adverse effect level (NOAEL) at 1151.7/115.2 mg/kg/day presented/deposited dose in rats.


Subject(s)
Lung Injury/chemically induced , Phytol/toxicity , Propylene Glycol/toxicity , Animals , Female , Inhalation Exposure , Male , Rats , Rats, Sprague-Dawley
3.
Chem Biodivers ; 18(2): e2000897, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33410569

ABSTRACT

The chemical profile and phytotoxic action of Hibiscus trionum essential oil (EO) was studied. In total 17 compounds were identified via GC/MS, representing 94.18 % of the entire oil, with phytol (40.37 %) being the dominant constituent. Bioassay revealed that the EO inhibited root elongation of Medicago sativa and Amaranthus retroflexus by 32.66 % and 61.86 % at 5 mg/mL, respectively; meanwhile, the major component phytol also exhibited significant phytotoxic activity, suppressing radical elongation of Pennisetum alopecuroides, M. sativa and A. retroflexus by 26.08 %, 27.55 % and 43.96 % at 1 mg/mL, respectively. The fact that the EO showed weaker activity than phytol implied that some constituents might trigger antagonistic action to decrease the oil's activity. Our study is the first on the chemical profile and phytotoxic effect of H. trionum EO.


Subject(s)
Hibiscus/chemistry , Oils, Volatile/chemistry , Phytol/chemistry , Amaranthus/drug effects , Amaranthus/growth & development , Gas Chromatography-Mass Spectrometry , Hibiscus/toxicity , Medicago sativa/drug effects , Medicago sativa/growth & development , Oils, Volatile/toxicity , Phytol/toxicity , Plant Roots/drug effects , Plant Roots/growth & development , Toxicity Tests
4.
Molecules ; 23(8)2018 Aug 08.
Article in English | MEDLINE | ID: mdl-30096781

ABSTRACT

Current study reveals the likelihood to use pathogen and toxin mutually as an effective and eco-friendly strategy for Oligonychus afrasiaticus (McGregor) management, which could reduce toxicant dose and host killing time. Therefore, phytol and Beauveria bassiana in different proportions were evaluated to determine their effectiveness. Prior to ascertaining host mortality and defense mechanisms, we have recorded in vitro action of phytol using different concentrations (0.70, 1.40, 2.10, 2.80, and 3.50 mg/mL) against B. bassiana suspension. In vitro compatibility assays revealed that growth parameters (vegetative growth, sporulation, and viability) of B. bassiana were least affected by the action of phytol at all tested concentrations. Biological Index of B. bassiana exhibited compatibility with phytol allowed us to conduct Joint toxicity bioassays in which phytol and spores mixed in different proportions in order to attain maximum treatment effect in terms of high mortality at low concentration under short time. Results revealed that joint-application exhibited both synergistic (treatments with higher proportions of phytol), and antagonistic interaction (treatments with higher proportions of spores) interactions. Biochemical mechanisms involved in host antioxidant and detoxification response were explored by quantifying their respective enzymatic activities. Lethality of different treatments induced different patterns of detoxification enzymes including glutathione S-transferase (GST) and acetylcholinesterase (AchE). Overall, the least potent treatments (20% phytol:80% spores, and 40% phytol:60% spores) established in the current study induced relatively higher GST and AchE activities. On the other hand, the most potent treatment (80% phytol:20% spores) at its maximum concentration exhibited negligible relative GST and AchE activities. Antioxidant enzyme activities of CAT and SOD measured in the current study showed moderate to complex interaction might because of toxin-pathogen remarkable synergy. This study suggested that joint application of phytol with B. bassiana spores have shown tremendous acaricidal potential and found to be promising new strategy for controlling old world date mites.


Subject(s)
Antioxidants/pharmacology , Beauveria/physiology , Phytol/toxicity , Tetranychidae/physiology , Acetylcholinesterase/metabolism , Animals , Beauveria/isolation & purification , Catalase/metabolism , Glutathione Transferase/metabolism , Inactivation, Metabolic , Superoxide Dismutase/metabolism , Tetranychidae/drug effects , Tetranychidae/enzymology , Toxicity Tests
5.
Biomed Pharmacother ; 105: 742-752, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29908495

ABSTRACT

In the present study, the antiproliferative activity of phytol and its mechanism of action against human lung adenocarcinoma cell line A549 were studied in detail. Results showed that phytol exhibited potent antiproliferative activity against A549 cells in a dose and time-dependent manner with an IC50 value of 70.81 ±â€¯0.32 µM and 60.7 ±â€¯0.47 µM at 24 and 48 h, respectively. Phytol showed no adverse toxic effect in normal human lung cells (L-132), but mild toxic effect was observed when treated with maximum dose (67 and 84 µM). No membrane-damaging effect was evidenced by PI staining and SEM analysis. The results of mitochondrial membrane potential analysis, cell cycle analysis, FT-IR and Western blotting analysis clearly demonstrated the molecular mechanism of phytol as induction of apoptosis in A549 cells, as evidenced by formation of shrinked cell morphology with membrane blebbing, depolarization of mitochondrial membrane potential, increased cell population in the sub-G0 phase, band variation in the DNA and lipid region, downregulation of Bcl-2, upregulation of Bax and the activation of caspase-9 and -3. In addition, phytol inhibited the CAM vascular growth as evidenced by CAM assay, which positively suggests that phytol has anti-angiogenic potential. Taken together, these findings clearly demonstrate the mode of action by which phytol induces cell death in A549 lung adenocarcinoma cells.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Apoptosis/drug effects , Cell Proliferation/drug effects , Membrane Potential, Mitochondrial/drug effects , Phytol/pharmacology , A549 Cells , Angiogenesis Inhibitors/toxicity , Cell Cycle/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Humans , Phytol/toxicity , Time Factors
6.
Chemosphere ; 177: 93-101, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28284120

ABSTRACT

Phytol (PYT) is a diterpenoid having important biological activity. However, it is a water non-soluble compound. This study aims to prepare PYT nanoemulsion (PNE) and evaluation of toxic, cytotoxic and genotoxic activities of PYT and PNE. For this, the PNE was prepared by the phase inversion method. The cytotoxicity test was performed in Artemia salina, while toxicity, cytotoxicity and genotoxicity in Allium cepa at concentrations of 2, 4, 8 and 16 mM. Potassium dichromate and copper sulfate were used as positive controls for the tests of A. salina and A. cepa, respectively. In addition, an adaptation response was detected in A. cepa by using the comet assay. The results suggest that both PYT and PNE exhibited toxic and cytotoxic effects at 4-16 mM in either test system, while genotoxicity at 2-16 mM in A. cepa. PNE exhibited more toxic, cytotoxic and genotoxic effects at 8 and 16 mM than the PYT. However, both PYT and PNE at 2 and 4 mM decreased the index and frequency of damage in A. cepa after 48 and 72 h, suggesting a possible adaptation response or DNA damage preventing capacity. Nanoemulsified PYT (PNE) may readily cross the biological membranes with an increase in bioavailability and produce more toxic, cytotoxic and genotoxic effects in the used test systems.


Subject(s)
Artemia/growth & development , DNA Damage/drug effects , Nanoparticles/toxicity , Onions/cytology , Phytol/toxicity , Animals , Artemia/drug effects , Comet Assay , Emulsions/chemistry , Emulsions/toxicity , Nanoparticles/chemistry , Onions/drug effects
7.
Biochim Biophys Acta ; 1851(10): 1394-405, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26248199

ABSTRACT

α-Methylacyl-CoA racemase (Amacr) catalyzes the racemization of the 25-methyl group in C27-intermediates in bile acid synthesis and in methyl-branched fatty acids such as pristanic acid, a metabolite derived from phytol. Consequently, patients with Amacr deficiency accumulate C27-bile acid intermediates, pristanic and phytanic acid and display sensorimotor neuropathy, seizures and relapsing encephalopathy. In contrast to humans, Amacr-deficient mice are clinically symptomless on a standard laboratory diet, but failed to thrive when fed phytol-enriched chow. In this study, the effect and the mechanisms behind the development of the phytol-feeding associated disease state in Amacr-deficient mice were investigated. All Amacr-/- mice died within 36weeks on a phytol diet, while wild-type mice survived. Liver failure was the main cause of death accompanied by kidney and brain abnormalities. Histological analysis of liver showed inflammation, fibrotic and necrotic changes, Kupffer cell proliferation and fatty changes in hepatocytes, and serum analysis confirmed the hepatic disease. Pristanic and phytanic acids accumulated in livers of Amacr-/- mice after a phytol diet. Microarray analysis also revealed changes in the expression levels of numerous genes in wild-type mouse livers after two weeks of the phytol diet compared to a control diet. This indicates that detoxification of phytol metabolites in liver is accompanied by activation of multiple pathways at the molecular level and Amacr-/- mice are not able to respond adequately. Phytol causes primary failure in liver leading to death of Amacr-/- mice thus emphasizing the indispensable role of Amacr in detoxification of α-methyl-branched fatty acids.


Subject(s)
Chemical and Drug Induced Liver Injury/metabolism , Phytol/toxicity , Racemases and Epimerases/deficiency , Animals , Bile Acids and Salts/genetics , Bile Acids and Salts/metabolism , Brain/metabolism , Brain/pathology , Chemical and Drug Induced Liver Injury/genetics , Chemical and Drug Induced Liver Injury/pathology , Gene Expression Regulation/drug effects , Kidney/metabolism , Kidney/pathology , Kupffer Cells/metabolism , Kupffer Cells/pathology , Mice , Mice, Knockout
9.
Article in Portuguese | LILACS | ID: lil-658501

ABSTRACT

O fitol, (3,7,11,15-tetrametilhexadec-2-en-1-ol), é um diterpeno pertencente ao grupo dos álcoois acíclicos insaturados de cadeia longa e ramificada. É um componente da molécula da clorofila, presente em folhas verdes de várias plantas medicinais. Entretanto, pouco é descrito na literatura sobre os possíveis efeitos toxicológicos produzidos pelo fitol. O objetivo do nosso estudo foi avaliar a toxicidade aguda do fitol, após administração intraperitoneal para determinação da dose letal 50% (DL50) e os efeitos sobre os parâmetros bioquímicos, hematológicos e histopatológicos no hipocampo e corpo estriado de camundongos adultos tratados com fitol nas doses de 25, 50 e 75 mg/kg. Os testes para determinação do grau de toxicidade aguda, bem como a investigação da DL50, revelou que o valor é aproximadamente 1153.39 mg/kg. Os camundongos tratados com as doses selecionadas do fitol a partir da DL50 apresentaram todos os parâmetros hematológicos dentro da faixa de referência, observando-se alterações nos valores dos linfócitos. Por sua vez, a maioria dos valores dos parâmetros bioquímicos diminuiu em todas as doses testadas (p<0,05). Em nosso estudo, apenas os animais tratados com fitol na dose de 75 mg/kg demonstraram uma discreta vacuolização no corpo estriado e um discreto comprometimento caracterizado por vacuolização no hipocampo em apenas um dos animais. Nossos resultados indicam que o tratamento com fitol não produz alterações hematológicas, bioquímicas e histopatológicas cerebrais em camundongos. O estudo toxicológico pré-clínico com fitol demonstrou que o produto avaliado possui discreta toxicidade aguda por via intraperitoneal, sendo estes dados uma contribuição para pesquisas com compostos obtidos de plantas medicinais com potencial farmacológico. Porém, ressalta-se a necessidade de futuras pesquisas que possibilitem comparar os resultados em outras vias, bem como para realizar análises anatomopatológicas dos animais tratados com fitol, para assegurar o uso seguro deste diterpeno.


Phytol (3,7,11,15-tetramethylhexadec-2-en-1-ol) is a diterpene belonging to the group of acyclic unsaturated long-chain branched alcohols. It is a component of the chlorophyll molecule, present in green leaves of various medicinal plants. However, there is little in the literature about the possible toxic effects produced by phytol. The aim of our study was to assess the acute toxicity of phytol after intraperitoneal (ip) administration, by determining its 50% lethal dose (LD50) and effects on biochemical parameters, hematology and the histopathology of the hippocampus and corpus striatum of adult mice treated with doses of 25, 50 and 75 mg/kg phytol. The acute toxicity tests and investigation of the LD50 revealed its value to be approximately 1153.39 mg/kg. Mice treated with sublethal doses of phytol based on the LD50 showed all hematological parameters within their reference ranges, with small changes in the lymphocyte count. In turn, most of the biochemical parameters decreased at all doses tested (p<0.05). In our study, only those animals treated with phytol at a dose of 75 mg/kg showed slight vacuolation in the corpus striatum and a slight impairment characterized by vacuolation in the hippocampus in one animal. Our results indicate that treatment with phytol produces no hematological, biochemical or brain histopathological changes in the mice. The preclinical toxicological study with phytol showed that it has slight acute toxicity when injected ip. These data contribute to research on natural compounds obtained from medicinal plants with pharmacological potential. However, we emphasize the need for future research to enable results obtained by other routes to be compared, as well as to conduct pathological analysis in animals treated with phytol, to ensure the safe use of this diterpene.


Subject(s)
Animals , Male , Mice , Phytol/toxicity , Mice
10.
Cell Immunol ; 271(2): 308-18, 2011.
Article in English | MEDLINE | ID: mdl-21855057

ABSTRACT

Terpenoids are ubiquitous natural compounds that have been shown to improve vaccine efficacy as adjuvants. To gain an understanding of the structural features important for adjuvanticity, we studied compounds derived from a diterpene phytol and assessed their efficacy. In a previous report, we showed that phytol and one of its derivatives, PHIS-01 (a phytol-derived immunostimulant, phytanol), are excellent adjuvants. To determine the effects of varying the polar terminus of PHIS-01, we designed amine and mannose-terminated phytol derivatives (PHIS-02 and PHIS-03, respectively). We studied their relative efficacy as emulsions with soluble proteins, ovalbumin, and a hapten-protein conjugate phthalate-KLH. Immunological parameters evaluated consisted of specific antibody responses in terms of titers, specificities and isotype profiles, T cell involvement and cytokine production. Our results indicate that these new isoprenoids were safe adjuvants with the ability to significantly augment immunogen-specific IgG1 and IgG2a antibody responses. Moreover, there was no adverse phthalate cross-reactive anti-DNA response. Interestingly, PHIS-01 and PHIS-03 influenced differentially T-helper polarization. We also observed that these compounds modulated the immune response through apoptotic/necrotic effects on target tumor cells using murine lymphomas. Finally, unlike squalene and several other terpenoids reported to date, these phytol derivatives did not appear arthritogenic in murine models.


Subject(s)
Adjuvants, Immunologic/administration & dosage , Adjuvants, Immunologic/chemistry , Phytol/analogs & derivatives , Vaccines/administration & dosage , Adjuvants, Immunologic/toxicity , Animals , Apoptosis/drug effects , Apoptosis/immunology , Cytokines/biosynthesis , Diterpenes/administration & dosage , Diterpenes/immunology , Emulsions , Female , Haptens/administration & dosage , Hemocyanins/administration & dosage , Immunity, Humoral/drug effects , Immunoglobulin Class Switching/drug effects , Immunoglobulin G/biosynthesis , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Necrosis/immunology , Ovalbumin/administration & dosage , Ovalbumin/immunology , Phthalic Acids/administration & dosage , Phytol/administration & dosage , Phytol/immunology , Phytol/toxicity , T-Lymphocytes, Helper-Inducer/drug effects , T-Lymphocytes, Helper-Inducer/immunology
11.
Food Chem Toxicol ; 48 Suppl 3: S59-63, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20141879

ABSTRACT

A toxicological and dermatologic review of phytol when used as a fragrance ingredient is presented.


Subject(s)
Odorants , Phytol/toxicity , Animals , Carcinogenicity Tests , Humans , Mucous Membrane/drug effects , Mutagenicity Tests , Phytol/pharmacokinetics , Reproduction/drug effects , Skin/drug effects , Teratogens/toxicity
12.
Food Chem Toxicol ; 48 Suppl 3: S76-81, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20141882

ABSTRACT

A toxicologic and dermatologic review of isophytol when used as a fragrance ingredient is presented.


Subject(s)
Odorants , Phytol/analogs & derivatives , Animals , Carcinogenicity Tests , Humans , Mucous Membrane/drug effects , Mutagenicity Tests , Phytol/pharmacokinetics , Phytol/toxicity , Reproduction/drug effects , Skin/drug effects , Teratogens/toxicity
13.
Bioorg Med Chem Lett ; 20(2): 508-12, 2010 Jan 15.
Article in English | MEDLINE | ID: mdl-20004575

ABSTRACT

Phytol, a diterpene alcohol was modified to several semisynthetic analogues. Some of the modifications were done logically to enhance lipophilicity of the molecule. Analogues 14, 16 and 18 exhibited antitubercular activity (MIC 15.6-50microg/mL) better than phytol (100microg/mL). The most potent analogue 18 was evaluated for in vivo toxicity in Swiss albino mice and was well tolerated by the experimental animals up to 300mg/kg body weight as a single oral acute dose.


Subject(s)
Antitubercular Agents/chemical synthesis , Oximes/chemical synthesis , Phytol/analogs & derivatives , Animals , Antitubercular Agents/chemistry , Antitubercular Agents/toxicity , Mice , Microbial Sensitivity Tests , Mycobacterium tuberculosis/drug effects , Oximes/chemistry , Oximes/toxicity , Phytol/chemical synthesis , Phytol/chemistry , Phytol/toxicity
14.
Arch Toxicol ; 78(11): 660-8, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15558240

ABSTRACT

Previous studies in our laboratory identified retinoid-induced defects that are mediated by RAR-RXR heterodimerization using interaction of synthetic ligands selective for the retinoid receptors RAR and RXR in mice (Elmazar et al. 1997, Toxicol Appl Pharmacol 146:21-28; Elmazar et al. 2001, Toxicol Appl Pharmacol 170:2-9; Nau and Elmazar 1999, Handbook of experimental pharmacology, vol 139, Retinoids, Springer-Verlag, pp 465-487). The present study was designed to investigate whether these RAR-RXR heterodimer-mediated defects can be also induced by interactions of natural and synthetic ligands for retinoid receptors. A non-teratogenic dose of the natural RXR agonist phytanic acid (100 mg/kg orally) or its precursor phytol (500 mg/kg orally) was coadministered with a synthetic RARalpha-agonist (Am580; 5 mg/kg orally) to NMRI mice on day 8.25 of gestation (GD8.25). Furthermore, a non-teratogenic dose of the synthetic RXR agonist LGD1069 (20 mg/kg orally) was also coadministered with the natural RAR agonist, all- trans-retinoic acid (atRA, 20 mg/kg orally) or its precursor retinol (ROH, 50 mg/kg orally) to NMRI mice on GD8.25. The teratogenic outcome was scored in day-18 fetuses. The incidence of Am580-induced resorptions, spina bifida aperta, micrognathia, anotia, kidney hypoplasia, dilated bladder, undescended testis, atresia ani, short and absent tail, fused ribs and fetal weight retardation were potentiated by coadministration of phytanic acid or its precursor phytol. Am580-induced exencephaly and cleft palate, which were not potentiated by coadministration with the synthetic RXR agonists, were also not potentiated by coadministration with either phytanic acid or its precursor phytol. LGD1069 potentiated atRA- and ROH-induced resorption, exencephaly, spina bifida, aperta, ear anotia and microtia, macroglossia, kidney hypoplasia, undescended testis, atresia ani, tail defects and fetal weight retardation, but not cleft palate. These results suggest that synergistic teratogenesis can be induced by coadministration of a natural RXR ligand (phytanic acid) with a synthetic RAR agonist (Am580). Thus, certain potentially useful therapeutic agents or nutritional factors such as phytanic acid should be tested for teratogenic risk by coadministration with other retinoid receptor agonists.


Subject(s)
Abnormalities, Drug-Induced/etiology , Prenatal Exposure Delayed Effects , Receptors, Retinoic Acid/agonists , Retinoid X Receptors/agonists , Teratogens/toxicity , Administration, Oral , Animals , Benzoates/toxicity , Bexarotene , Dose-Response Relationship, Drug , Drug Synergism , Female , Gestational Age , Ligands , Mice , Mice, Inbred Strains , Phytanic Acid/toxicity , Phytol/toxicity , Pregnancy , Retinoic Acid Receptor alpha , Tetrahydronaphthalenes/toxicity , Tretinoin/toxicity , Vitamin A/toxicity
15.
Toxicol Sci ; 66(2): 274-82, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11896294

ABSTRACT

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.


Subject(s)
Abnormalities, Drug-Induced/prevention & control , Phytanic Acid/pharmacology , Phytol/pharmacology , Teratogens/toxicity , Tretinoin/toxicity , Vitamin A/toxicity , Administration, Oral , Animals , Chromatography, High Pressure Liquid , Drug Synergism , Female , Mice , Mice, Inbred Strains , Phytanic Acid/toxicity , Phytol/toxicity , Pregnancy , Prenatal Exposure Delayed Effects , Teratogens/pharmacokinetics , Tretinoin/antagonists & inhibitors , Tretinoin/pharmacokinetics , Vitamin A/antagonists & inhibitors , Vitamin A/pharmacokinetics
16.
Jpn J Cancer Res ; 90(4): 377-84, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10363574

ABSTRACT

Phytol is a branched, long-chain aliphatic alcohol which has various biological effects. In this study, we examined phytol as a tumor promoter in a mouse skin initiation-promotion model, and compared its promotion activity with that of 12-O-tetradecanoyl phorbol-13-acetate (TPA). Female ICR mice, 7 weeks of age, were initiated with 100 microg of 7,12-dimethylbenz(a)anthracene, and were then topically promoted twice a week for 16 weeks with 100 mg of phytol or with 2.5 microg of TPA. In this model 95% of animals treated with phytol developed skin tumors within 16 weeks. The average number of lesions per mouse treated with phytol was significantly lower than that in mice treated with TPA, and this significant difference continued up to 16 weeks after the end of promotion treatment. Characterization of hyperplasia 48 h after topical application of agents showed that epidermal thickness and vertical thickness following topical application of phytol were significantly increased compared with vehicle controls, but were significantly smaller than in animals treated with TPA. Ornithine decarboxylase (ODC) activity following topical application of phytol was increased in a dose-dependent manner and showed a weak, delayed induction (which was maximal 11-12 h after treatment) as compared with the case of TPA. The specific binding of [3H]phorbol-12,13-dibutyrate (PDBU) by JB6 cells was not inhibited by phytol at concentrations up to 1 mM. These results indicate that phytol has a weak tumor promoter activity compared to TPA and is a non-TPA-type tumor promoter in this model of mouse skin carcinogenesis.


Subject(s)
Carcinogens/toxicity , Phytol/toxicity , Animals , Female , Hyperplasia/chemically induced , Hyperplasia/enzymology , Mice , Mice, Inbred ICR , Ornithine Decarboxylase/metabolism , Radioligand Assay , Tetradecanoylphorbol Acetate/toxicity , Toxicity Tests
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