RESUMEN
This publication is part of a series of 3 publications and describes the clinical assessment performed to fulfill the regulatory requirement per Art. 6 (2) of the EU Tobacco Products Directive 2014/40/EU under which Member States require manufacturers and importers of cigarettes and Roll Your Own tobacco containing an additive that is included in the priority list established by Commission Implementing Decision (EU) 2016/787 to carry out comprehensive studies (European Union, 2016). In our clinical study, two distinct end points were investigated, namely measuring plasma nicotine pharmacokinetics as a measure of nicotine uptake, and analyses of changes in smoker puffing behavior as a measure of cigarette smoke inhalation. This clinical study indicated that the inclusion of none of the priority additives either as single additive or as part of a chemical mixture, facilitated nicotine uptake. Furthermore, the data did not suggest that differences in the inhalation pattern of cigarette smoke of any of the Priority Additives tested occurred when compared to the additive-free reference cigarette. Finally, it is concluded that neither the scientific literature nor our study gave circumstantial indications of increased addictiveness for cigarettes containing these priority additives.
Asunto(s)
Unión Europea , Aromatizantes/normas , Nicotina/sangre , Nicotina/farmacocinética , Fumar/psicología , Industria del Tabaco/legislación & jurisprudencia , Productos de Tabaco/normas , Aromatizantes/análisis , Humanos , Productos de Tabaco/análisisRESUMEN
The objective of this study was to evaluate the effects of cigarette filters on the chemical composition and toxicity of cigarette mainstream smoke. In this work, we used three types of cigarettes, including non-filter 2R4F cigarettes, cellulose acetate (CA)-filter 2R4F cigarettes, and carbon dual-filter 2R4F cigarettes. The cytotoxicity of TPM obtained from the filter cigarettes was not different from that of the non-filter cigarettes on an equal TPM basis. However, the EC50 value of GVP from carbon-filter cigarettes were 40.9 puffs/L, thereby indicating the cytotoxicity of these cigarettes was approximately 37% and 21% lower than non-filter and CA-filter cigarettes, respectively. The cytotoxicity of GVP was correlated with carbonyl components. The mutagenicity of TPM obtained from non-filter cigarettes, calculated on an equal TPM basis, was up to 30-40% lower than that of the filter cigarettes. When calculated on a per cigarette basis, the mutagenicity of CA or carbon-filter cigarettes was found to be 35% lower than that of the non-filter cigarettes. The results of chemical composition analyses revealed that the observed increase in aromatic amine compound yields on an equal TPM basis in filter cigarettes may be related with the mutagenic activity determined in Ames assays.
Asunto(s)
Filtración/instrumentación , Nicotiana/toxicidad , Humo/efectos adversos , Humo/análisis , Animales , Células CHO , Carbono/química , Supervivencia Celular , Cricetinae , Cricetulus , Citotoxinas , Relación Dosis-Respuesta a Droga , Pruebas de Mutagenicidad , Mutágenos , Salmonella typhimurium/efectos de los fármacos , Nicotiana/químicaRESUMEN
TLR4 together with CD14 and MD-2 forms a pattern recognition receptor that plays an initiating role in the innate immune response to Gram-negative bacteria. Here, we employed the surface plasmon resonance technique to investigate the kinetics of binding of LPS to recombinant CD14, MD-2 and TLR4 proteins produced in insect cells. The dissociation constants (KD) of LPS for immobilized CD14 and MD-2 were 8.7 microM, and 2.3 microM, respectively. The association rate constant (Kon) of LPS for MD-2 was 5.61 x 10(3) M-1S-1, and the dissociation rate constant (Koff) was 1.28 10 2 S 1, revealing slow association and fast dissociation with an affinity constant KD of 2.33 x 10-6 M at 25 degreesC. These affinities are consistent with the current view that CD14 conveys LPS to the TLR4/MD-2 complex.
Asunto(s)
Receptores de Lipopolisacáridos/química , Lipopolisacáridos/química , Antígeno 96 de los Linfocitos/química , Receptor Toll-Like 4/química , Animales , Cinética , Ratones , Unión Proteica , Proteínas Recombinantes/química , SolubilidadRESUMEN
Nitric oxide (NO) has various physiological functions. However, uncontrolled overproduction of NO can be toxic in many pathologic conditions involving inflammatory tissue damage. In the present study, we examined effects of 23,24-dihydrocucurbitacin D (DHCD) isolated from the root of Bryonia alba L. on macrophage NO generation. DHCD (<80 microM) effectively abolished NO generation from macrophages activated with lipopolysaccharide and interferon-gamma. DHCD decreased the levels of protein and mRNA for inducible NO synthase (iNOS). DHCD potently blocked nuclear factor-kappaB (NF-kappaB) activation, a process necessary for transcriptional activation of iNOS. These results suggested that DHCD inhibited NO generation by blocking NF-kappaB activation and iNOS gene transcription. Because NF-kappaB activation is necessary not only for NO generation but also for many inflammatory processes, DHCD and its derivatives could be developed as anti-inflammatory drugs.
Asunto(s)
Macrófagos Peritoneales/efectos de los fármacos , Óxido Nítrico/metabolismo , Triterpenos/farmacología , Animales , Células Cultivadas , Expresión Génica/efectos de los fármacos , Macrófagos Peritoneales/metabolismo , Ratones , FN-kappa B/metabolismo , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico Sintasa de Tipo IIRESUMEN
The effects of the subchronic administration of Panax ginseng extracts were examined on the hepatic cytochrome P450-dependent monooxygenase system of guinea pigs pre-exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Panax ginseng extracts were intraperitoneally administered to guinea pigs at 100 mg/kg/day for 14 days from 1 week after a single intraperitoneal injection of 1 microg of TCDD/kg of body weight. TCDD treatment increased the total cytochrome P450 content 2.86-fold, and this was remarkably inhibited by the administration of Panax ginseng extracts. Treatment with ginseng extract alone also decreased the contents of cytochrome P450 by 33%, but both TCDD and ginseng extracts had no effect on cytochrome b(5) content. The administration of TCDD resulted in a 1.73-fold increase in microsomal NADPH-cytochrome P450 reductase activity in the guinea pig liver, and this was significantly inhibited by ginseng extracts, but treatment with ginseng extracts alone had no effect on its activity, and no statistical changes in the activity of NADPH-cytochrome b(5) reductase were observed in guinea pig liver due to TCDD and/or ginseng extract administration. Compared to the control, ECOD activity remarkably (1.76-fold) increased after TCDD administration, but this increase was completely inhibited by treatment with ginseng extract. Treatment with ginseng extract alone resulted in a 50% reduction of ECOD activity. TCDD administration remarkably induced benzphetamine demethylation (BPDM) activity, while ginseng extract also slightly increased the enzyme's activity, but the induction attributed to ginseng extracts was not statistically significant. Even though administration of ginseng extracts slightly inhibited TCDD-induced BPDM activity, the inhibition was not statistically significant. These results indicate that ginseng extract exerts different effect on the induction of P450 isozymes. From these results, we suggest that Panax ginseng extracts may act as an inhibitor of CYP1A rather than that of CYP2B.