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1.
Eur J Pain ; 19(7): 940-52, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25400173

RESUMO

BACKGROUND: Rheumatoid arthritis (RA), a chronic and systemic inflammation, results in destruction of joints and cartilages. Effectiveness of curcumin has been established in a wide variety of inflammatory disorders, but its utility as a therapeutic agent is limited by its poor absorption, rapid metabolism and fast systemic elimination. To apprehend these limitations, we propose to use highly bioavailable curcumin loaded solid lipid nanoparticles (C-SLNs) for the treatment of RA. METHODS: In the present study, the protective effect of curcumin and its SLNs was evaluated in complete Freund's adjuvant (CFA)-induced arthritis in rats. RESULTS: Arthritic rats exhibited marked decrease in paw withdrawal threshold in Randall-Selitto and von Frey hair test along with decreased reaction time in hot plate. Arthritic rats also showed significant joint hyperalgesia, joint stiffness and increased paw volume along with marked decrease in mobility score. Arthritic rats showed a significant increase in blood leukocyte count, oxidative-nitrosative stress, tumour necrosis factor-α, C-reactive protein, cyclic citrullinated peptide antibody levels and radiological alterations in tibiotarsal joint. C-SLN administration (10 and 30 mg/kg), when compared with free curcumin (10 and 30 mg/kg), significantly and dose dependently ameliorated various symptoms of arthritis in rats, improved biochemical markers and preserved radiological alterations in joints of arthritic rats. CONCLUSIONS: The current findings suggest the protective potential of curcumin-SLNs in ameliorating CFA-induced arthritis in rats through attenuation of oxido-inflammatory and immunomodulatory cascade. Further, the results emphasize that SLNs are a novel approach to deliver curcumin into the inflamed joints and improve its biopharmaceutical performance.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite Experimental/tratamento farmacológico , Curcumina/uso terapêutico , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Curcumina/administração & dosagem , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Adjuvante de Freund , Hiperalgesia/tratamento farmacológico , Hiperalgesia/etiologia , Articulações/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Lipossomos , Masculino , Nanopartículas , Estresse Oxidativo/efeitos dos fármacos , Medição da Dor/efeitos dos fármacos , Ratos , Ratos Wistar
2.
Climacteric ; 16(4): 426-37, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23017032

RESUMO

OBJECTIVE: Estrogen deprivation after menopause is associated with increased oxidative stress. The present study was designed to study the role of sesamol (3,4-methylenedioxyphenol), a phenolic antioxidant and anti-inflammatory molecule, in oxidative stress-induced changes in three major affected organ systems, the central nervous system, the cardiovascular system and the skeletal system in ovariectomized rats, a widely used animal model of menopause. DESIGN: Animals were divided into eight different groups (n = 6-8). Five groups underwent ovariectomy; starting from the 2nd day of ovariectomy, three of these groups received sesamol (2, 4, 8 mg/kg) and the fourth group was administered α-tocopherol (100 mg/kg) orally for 7 weeks. The fifth ovariectomized group did not receive any drug treatment. Rats in the naïve (non-operated) and sham-operated groups did not receive any drug treatment, while the eighth group consisted of naïve animals which were treated for 7 weeks with only sesamol 8 mg/kg orally daily. After 7 weeks, animals were subjected to testing of behavioral paradigms (elevated plus maze and Morris water maze for assessment of anxiety and memory, respectively) 24 h after the last dose. After behavioral studies, animals were sacrificed for various biochemical estimations. RESULT: Administration of sesamol (2, 4, 8 mg/kg orally) to ovariectomized rats for 7 weeks significantly and dose-dependently improved memory, attenuated anxiety, decreased oxidative stress in brain, improved the serum lipid profile and reduced serum tumor necrosis factor-α levels when compared with ovariectomized control rats. Similar protective effects were observed in the case of the skeletal system studies. Sesamol increased the bone ash content and the mechanical stress parameters in treated groups. CONCLUSION: The results emphasize the involvement of oxidative stress and inflammation in the development of ovariectomy-induced pathophysiological changes and point towards the therapeutic potential of sesamol in menopausal pathologies.


Assuntos
Antioxidantes/administração & dosagem , Benzodioxóis/administração & dosagem , Menopausa Precoce/efeitos dos fármacos , Ovariectomia , Fenóis/administração & dosagem , Animais , Ansiedade , Peso Corporal/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Estradiol/sangue , Feminino , Peroxidação de Lipídeos/efeitos dos fármacos , Lipídeos/sangue , Memória/efeitos dos fármacos , Menopausa Precoce/fisiologia , Modelos Animais , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/sangue , Útero/anatomia & histologia
3.
Neurogastroenterol Motil ; 24(4): 366-e170, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22296294

RESUMO

BACKGROUND: In recent years the interface between neuropsychiatry and gastroenterology has converged in to a new discipline referred to as enteric neuroscience. Implications of brain-gut communication in the pathogenesis of psychiatric disorders indicate a possible role of suitably packaged/delivered probiotics as newer therapeutic options. In the present study probable role of per-oral administration of free Lactobacillus acidophilus (LAB) and LAB loaded alginate beads in attenuation of the symptoms associated with chronic fatigue syndrome (CFS) were evaluated. METHODS: Chronic fatigue syndrome following physical fatigue was induced in rats by forcing them to swim (forced swim test; FST) in water till exhaustion, after weighing them down with 10% their body weight, daily for 28 days. Immobility (I) and postswim fatigue time (PSF) were taken as suitable markers. Free LAB and LAB loaded floating beads (FBs) were administered, from 21 to 28 days. KEY RESULTS: Immobility and PSF were found to increase considerably in FST rats (665 ± 22 s and 196 ± 6 s) as compared with the naïve (32 ± 7 s and 22 ± 2 s) at 20 days, establishing severe fatigue like behavior. FST control group exhibited significant (P < 0.05) hypertrophy of spleen, hypotrophy of thymus, and increased oxido-nitrosative stress in brain and tumor necrosis factor-α (TNF-α) levels in serum. Treatment with LAB and LAB FBs significantly decreased I and PSF and attenuated (P < 0.05) oxido-nitrosative stress and TNF-α levels. Spleen and thymus were also restored to their original size in this group. CONCLUSIONS & INFERENCES: The findings suggest a valuable therapeutic role of LAB especially when incorporated into alginate beads for the treatment of CFS.


Assuntos
Síndrome de Fadiga Crônica/tratamento farmacológico , Lactobacillus acidophilus , Neuroimunomodulação/fisiologia , Probióticos/administração & dosagem , Alginatos , Animais , Comportamento Animal/efeitos dos fármacos , Cápsulas , Modelos Animais de Doenças , Síndrome de Fadiga Crônica/imunologia , Síndrome de Fadiga Crônica/fisiopatologia , Ácido Glucurônico , Ácidos Hexurônicos , Masculino , Estresse Oxidativo/fisiologia , Ratos , Ratos Wistar
4.
J Stem Cells Regen Med ; 7(2): 75-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-24693174

RESUMO

A rapid decline in self-renewability, viability and function, of isolated stem cells are major hurdles in developing cell based therapies. There has been an increasing interest towards identifying a support material for maintaining stem cell features of the isolated cells. Pioneering observations of the present paper, demonstrate functionally diverse potential of Solid Lipid Nanoparticles (SLNs) in deciding the fate & behavior of mouse mesenchymal stem cell. The evidences are provided to show the dual nature of the SLNs for being a scaffold for the stem cell attachment, to retain stemness, and as reagent for inducing stem cell differentiation. Scanning electron microscopic examinations together with expression analysis were used to conform to such observations. Results of the study thus suggest that Solid lipid nanoparticles can be used as a good support material when functionalized to achieve adhesive properties and as a molecular paradigm for studying the adipocytic differentiation. We envisage a new role of SLNs towards regulating stem cell character by orchestrating the structural alignment during preparation of Solid lipid nanoparticles.

5.
Maturitas ; 57(3): 306-14, 2007 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-17408889

RESUMO

OBJECTIVE: To study the variation of the menopause rating scale (MRS) scores with age, working/non-working and educated/uneducated status in a cohort of north-Indian subpopulation and to look for the possible reasons for the incurred variations. MRS is a well-known and validated instrument for assessing the frequency and intensity of menopausal symptoms. METHOD: A menopause clinic was organized in collaboration with a primary care centre (under the guidance of a gynecologist). A random sample of 208 women aged 35-65 years participated in the study. The MRS scale, a self-administered standardized questionnaire was applied with additional patient related information (age at menopause, level of education, working/non-working and exercising or not). RESULTS: The results were evaluated for psychological (P), somatic (S), and urogenital (U) symptoms. The average age at which menopause set in, in the cohort was found to be 48.7+/-2.3 years (46.4-51 years). Based on the average age at the menopause, the cohort was divided into peri (35-45), menopausal/early menopause (46-51) and the postmenopausal (52-65) groups. A significantly higher % of perimenopausal women (36%) showed a P score of > or =7; while a higher % of postmenopausal showed S score and U score > or =7 (>40%; p< or =0.001). Working women seem to suffer more from psychological symptoms whereas non-working women showed a greater incidence of somatic symptoms. Educated women showed a lower incidence of psychological and somatic symptoms. CONCLUSIONS: Present study indicates that age, level of education and working/non-working status (in a group of women with same socio-cultural background) may also contribute to significant variations in menopausal symptoms.


Assuntos
Fogachos/epidemiologia , Menopausa , Índice de Gravidade de Doença , Adulto , Fatores Etários , Idoso , Feminino , Fogachos/etiologia , Fogachos/patologia , Humanos , Índia/epidemiologia , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Inquéritos e Questionários
6.
Phytomedicine ; 10(6-7): 575-82, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-13678246

RESUMO

Dibenzoylmethane (DBM), a structural analogue of curcumin (a bioactive phytochemical present in a widely used spice turmeric) was screened for its inhibitory effect against seven cooked food mutagens (heterocyclic amines): 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), in both TA98 and TA100 strains of Salmonella typhimurium using Ames Salmonella/reversion assay in the presence of Aroclor1254-induced rat liver S9 homogenate. DBM has been reported to antagonize the mutagenicity of several chemical carcinogens in vitro and has recently been shown to be even more effective than curcumin in suppressing the 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in rats. But there are no reports regarding its antimutagenic properties against cooked food mutagens. Results of the present investigations clearly indicate that dibenzoylmethane is a very potent antimutagenic agent, that could effectively inhibit mutagenicity induced by all the tested cooked food mutagens in both the frame shift (TA98) as well as the base pair mutation sensitive (TA100) strains of S. typhimurium. These highly potent inhibitory effects of dibenzoylmethane against heterocyclic amines observed in our preliminary investigations strongly warrant further studies of its efficacy as a cancer chemopreventive agent.


Assuntos
Aminas/toxicidade , Antimutagênicos/farmacologia , Benzoatos/farmacologia , Chalconas , Alimentos , Fitoterapia , Aminas/antagonistas & inibidores , Animais , Humanos , Masculino , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/classificação , Salmonella typhimurium/genética
7.
Planta Med ; 69(2): 184-6, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12624832

RESUMO

The naturally derived isothiocyanate, sulphoraphene [4-isothiocyanato-(1R)-(methylsulphinyl)-1-(E)-butene], isolated from seeds of radish ( Raphanus sativus L., Cruciferae) was investigated for its antigenotoxic effects against a battery of cooked food mutagens (heterocyclic amines) in the Ames Salmonella/reversion assay using Salmonella typhimurium TA98 (frame-shift mutation sensitive) and TA100 (base -pair mutation sensitive) bacterial strains in the presence of Aroclor 1254 induced rat liver S9. Results of the present in vitro anti-mutagenicity studies using the base-pair mutation sensitive strain TA100, strongly suggest that sulphoraphene is a potent inhibitor of the S9-mediated mutagenicity of all the tested heterocyclic amines (60 - 75 % inhibition at a dose of 500 nmol/plate).


Assuntos
Aminas/toxicidade , Isotiocianatos/toxicidade , Mutagênicos/toxicidade , Fitoterapia , Raphanus , Animais , Compostos Heterocíclicos/toxicidade , Masculino , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Sementes
8.
Indian J Exp Biol ; 41(3): 216-9, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15267150

RESUMO

Sulforaphane, a constituent of broccoli was investigated for its antimutagenic potential against different classes of cooked food mutagens (heterocyclic amines). These include imidazoazaarenes such as 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP); pyridoindole derivatives such as 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2); and, dipyridoimidazole derivative such as 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1). Tests were carried out by Ames Salmonella/reversion assay using Salmonella typhimurium TA98 (frame shift mutation sensitive) and TA100 (base pair mutation sensitive) bacterial strains in the presence of Aroclor 1254-induced rat liver S9. Results of these in vitro antimutagenicity studies strongly suggest that sulforaphane is a potent inhibitor of the mutagenicity induced by imidazoazaarenes such as IQ, MeIQ and MeIQx (approximately 60% inhibition) and moderately active against pyridoindole derivatives such as Trp-P-1 and Trp-P-2 (32-48% inhibition), but ineffective against dipyridoimidazole derivative (Glu-P-1) in TA 100.


Assuntos
Aminas/toxicidade , Brassica/química , Análise de Alimentos , Mutagênicos/toxicidade , Animais , Biotransformação , Masculino , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética
9.
Indian J Exp Biol ; 40(12): 1365-72, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12974398

RESUMO

Curcumin (C) and its natural analogues demethoxycurcumin (dmC) and bisdemethoxycurcumin (bdmC), known for their potent anti-inflammatory, antioxidant, antimutagenic and anticarcinogenic effects, were tested for their possible inhibitory effects against seven cooked food mutagens (heterocyclic amines): 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-6-methyldipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1), in both TA98 and TA100 strains of Salmonella typhimurium using Ames Salmonella/reversion assay in the presence of Aroclor induced rat liver S9 homogenate. In the present investigations, curcumin as well as its two natural analogues i.e., dmC and bdmC were found to be highly effective in suppressing genotoxicity of all the tested cooked food mutagens in a dose-dependent manner, in both the frame shift (TA98) as well as base pair mutation sensitive (TA100) strains of S. typhimurium. However, bdmC appeared to be a relatively less active antimutagen compared to C and dmC. More than 80% inhibition of mutagenicity was observed at 200 microg/plate in case of C and dmC in both TA98 and TA100 against all tested cooked food mutagens. Where as, bdmC showed 39-79% inhibition in TA100 and 60-80% inhibition in TA98, at a dose of 200 microg/plate. These findings warrant further biochemical, enzymatic and in vivo investigations in animal models as well as in humans to establish the chemoprotective effect of these agents against mutagenic heterocyclic amines found in cooked food.


Assuntos
Aminas/toxicidade , Antimutagênicos/farmacologia , Curcumina/farmacologia , Alimentos , Aminas/antagonistas & inibidores , Testes de Mutagenicidade , Salmonella typhimurium/genética
10.
Mutat Res ; 470(1): 71-6, 2000 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-10986476

RESUMO

The effects of sesamol, a phenolic compound responsible for the high resistance of sesame oil to oxidative deterioration as compared with other vegetable oils, have been investigated after mutagen treatment in various strains of Salmonella typhimurium. Sesamol was shown to exhibit strong antimutagenic effects in the Ames tester strains TA100 and TA102. The TA102 strain has been shown to be highly sensitive to reactive oxygen species. Mutagenicity was induced by the generation of oxygen radicals by tert-butylhydroperoxide (t-BOOH) or hydrogen peroxide (H(2)O(2)); therefore, the antimutagenic property of sesamol was attributed to its antioxidant properties. The superoxide and hydroxyl radical scavenging capabilities have further been elucidated using in vitro test systems. It was further shown to have a desmutagenic effect on t-BOOH-induced mutagenesis in TA102 strain. Sesamol also inhibited the mutagenicity of sodium azide (Na-azide) in TA100 tester strain while it had no effect on nitroquinoline-N-oxide (NQNO)-induced mutagenesis in TA98 strain of Salmonella typhimurium. Since active oxygen species are involved in multiple stage processes of carcinogenicity, this compound may also exhibit anticarcinogenic properties.


Assuntos
Antimutagênicos/farmacologia , Antioxidantes/farmacologia , Fenóis/farmacologia , Espécies Reativas de Oxigênio , Benzodioxóis , Peróxido de Hidrogênio/toxicidade , Testes de Mutagenicidade , Salmonella typhimurium/efeitos dos fármacos , terc-Butil Hidroperóxido/toxicidade
11.
Int J Pharm ; 199(2): 119-27, 2000 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-10802405

RESUMO

The orally administered acetazolamide has a limited use in glaucoma due to the systemic side effects associated with its use. It has been reported to show little effect on the intraocular pressure (IOP) of human and rabbit eyes upon topical application, probably owing to its poor bioavailability and instability at pH >5.0. In order to enhance the bioavailability of the drug, contact time between the drug molecules and the ocular surface was increased using high viscosity, water soluble polymers (PVA, HPMC), and by incorporating acetazolamide into an in situ-forming ophthalmic drug delivery system. Moreover, a penetration enhancer (EDTA) was also used in these formulations to increase the extent of absorption of the drug. Acetazolamide at a concentration of 10% was used and the formulations (eyedrop suspensions) were evaluated for their in vitro release pattern. The effect of these formulations on the IOP in normotensive conscious rabbits was also investigated. These formulations were found to be therapeutically effective with a peak effect at 2 h. A fall in IOP of up to 46.4% was observed with repeated administration of one of the formulation containing PVA, EDTA and Tween 80 (MK-5). Results indicated that a topical effect of acetazolamide can be observed if the formulation, (a) contains a suitable polymer-to increase the residence time; (b) a penetration enhancer-as acetazolamide has a low permeability coefficient i.e. 4. 1x10(-6) cm/s [Duffel, M.W., Ing. I.S., Segarra, T.M., Dixson, J.A., Barfknecht, C.F., Schoenwald, R.D., 1986. J. Med. Chem. 29, 1488-1494]; and (c) pH of the formulation is maintained at the point of maximum stability (pH< or =5.0).


Assuntos
Acetazolamida/administração & dosagem , Animais , Composição de Medicamentos , Glaucoma/tratamento farmacológico , Humanos , Concentração de Íons de Hidrogênio , Pressão Intraocular/efeitos dos fármacos , Microesferas , Soluções Oftálmicas , Coelhos
12.
Mutat Res ; 335(3): 235-43, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8524338

RESUMO

The potential metabolites of nitroscanate(4-isothiocyanato-4'-nitrodiphenyl ether) such as 4-amino-4'-nitrodiphenyl ether (ANDE), 4-acetamido-4'-nitrodiphenyl ether (AcNDE), 4-acetamido-4'-nitrosodiphenyl ether (4-N = 0), 4-acetamido-4'-hydroxylaminodiphenyl ether (4-NHOH), 4-acetamido-4'-acetohydroxamicdiphenyl ether [4-N(OH)Ac], 4-acetamido-4'-formohydroxamicdiphenyl ether [4-N(OH)CHO] and 4-acetamido-4'-acetylaceto-hydroxamicdiphenyl ether [4-N(OAc)Ac] were synthesized and investigated in the standard Salmonella mutagenicity test using TA98, TA98NR, TA98/1,8-DNP6, TA100 and TA100NR as indicator strains, in the presence and absence of hepatic S9. The relative order of activity among nitro and its reduction products, 4-N = 0 and 4-NHOH in TA98 and TA100 was 4-N = 0 > 4-NHOH > AcNDE. In nitroreductase deficient strain TA98NR, AcNDE was inactive, but expressed a slight activity in TA100NR while 4-N = 0 and 4-NHOH showed a large increase in specific activity in both the strains. In O-acetyltransferase deficient strain TA98/1,8-DNP6, AcNDE was inactive, while 4-N = O and 4-NHOH showed a sharp fall in activity. The hydroxylamine derived products with an activity order 4-N(OAc)Ac > 4-N(OH)CHO > 4-N(OH)Ac in both TA98 and TA100, showed 3-6 times increase in the specific activity for the latter two compounds in the presence of S9 mix, which was inhibited in the presence of paraoxan, indicating N-deacylation as an important metabolic activation pathway. Except the 4-NO in TA100, the observed mutagenicity of nitroscante (NSC) was higher than those of potential metabolites and the nor-isothiocyanato derivative 4'-nitrodiphenyl ether, thereby showing that -NCS function has a potentiating effect on the mutagenicity of this drug.


Assuntos
Anticestoides/toxicidade , Éteres Fenílicos/toxicidade , Salmonella typhimurium/efeitos dos fármacos , Tiocianatos/toxicidade , Animais , Biotransformação , Desenho de Fármacos , Fígado/metabolismo , Camundongos , Testes de Mutagenicidade , Mutagênicos/toxicidade , Éteres Fenílicos/metabolismo , Salmonella typhimurium/genética , Tiocianatos/metabolismo
13.
Mutat Res ; 334(3): 273-81, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7753091

RESUMO

Nitroscanate (NSC) was found to be a direct acting mutagen in the Ames Salmonella tester strains TA100 and TA98 and this activity increased further in the presence of rat liver S9 mix. It was inactive in TA98NR and TA100NR, and weakly active in TA98/1,8-DNP6. A substantial fall in drug induced mutagenicity by pentachlorophenol, an inhibitor of acetyltransferase, in TA98, TA100 and YG1024 suggests the initial bioconversion of a nitro group to hydroxylamine and its further activation to the ultimate N-acetoxyarylamine. The refrigerated DMSO solution of the drug in the plate incorporation assay and freshly prepared solutions using the pre-incubation procedure indicated a fall in mutagenicity owing to the conversion of NSC to N,N'-bis-4-(p-nitrophenoxy)phenyl thiourea (NFPT). The drastic reduction in mutagenicity in the presence of 4-amino-4'-nitrodiphenyl ether (ANDE) and 4-aminodiphenyl ether (ADE) was also attributed to the conversion of NSC to the corresponding thiourea, a non-mutagen. The negligible mutagenicity of ANDE and its absence in ADE and 4-isothiocyanate diphenyl ether (ITDE) suggests that the mutagenicity of NSC is due to the nitro group, and the -NCS function is responsible for enhanced mutagenicity over nor-isothiocyanate 4-nitrodiphenyl ether (NDE).


Assuntos
Anti-Helmínticos/toxicidade , Mutagênicos , Éteres Fenílicos/toxicidade , Tiocianatos/toxicidade , Acetiltransferases/efeitos dos fármacos , Anticestoides/toxicidade , Relação Dose-Resposta a Droga , Mutagênese , Testes de Mutagenicidade , Pentaclorofenol/farmacologia , Éteres Fenílicos/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Relação Estrutura-Atividade , Tioureia/análogos & derivados
14.
Toxicol Lett ; 48(1): 75-81, 1989 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2665189

RESUMO

Among the different metabolites of o-toluidine only the nitroso and hydroxylamino derivatives were found to be very potent frameshift mutagens in the presence of the co-mutagen norharman and S9. In the absence of norharman and S9 they are only base pair mutagens. Norharman failed to evoke the mutagenicity of the non-carcinogenic m- and p-toluidine and their respective nitroso and hydroxylamino metabolites. This report highlights that norharman plays a role in the appearance of mutagenicity of certain carcinogenic amines and metabolites.


Assuntos
Alcaloides/toxicidade , Harmina/toxicidade , Mutagênicos , Toluidinas/toxicidade , Animais , Carbolinas , Interações Medicamentosas , Harmina/análogos & derivados , Isomerismo , Testes de Mutagenicidade , Ratos , Salmonella typhimurium/efeitos dos fármacos , Toluidinas/metabolismo
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