Different levels of brain-derived neurotrophic factor and cortisol in healthy heavy smokers

Studies suggest that brain-derived neurotrophic factor (BDNF) and the hypothalamic-pituitary-adrenal (HPA) axis modulate dopaminergic activity in response to nicotine and that the concentrations of BDNF and cortisol seem to be dependent on the amount and duration of smoking. Therefore, we investigated BDNF and cortisol levels in smokers ranked by daily cigarette consumption. Twenty-seven adult males (13 non-smokers and 14 smokers) participated in the study. The smokers were divided in two groups: light (n=7) and heavy smokers (n=7). Anthropometric parameters and age were paired between the groups, and plasma BDNF and salivary cortisol levels were measured. Saliva samples were collected on awakening, 30 min after awakening, at 10:00 and 12:00 am, 5:00 and 10:00 pm. Additionally, cotinine serum levels were measured in smokers. Heavy smokers had higher mean values of BDNF compared to the control group (P=0.01), whereas no difference was observed in light smokers. Moreover, heavy smokers presented lower cortisol levels in the last collection (10:00 pm) than the control group (P=0.02) and presented statically higher values of cotinine than the light smokers (P=0.002). In conclusion, changes in BDNF and cortisol levels (10:00 pm) appear to be dependent on heavy cigarette smoking and can be involved in activation and in the relationship between the mesolimbic system and the HPA axis.

Oxidative stress and skeletal muscle dysfunction are present in healthy smokers

Chronic exposure to cigarette smoke seems to be related to an increase of pro-inflammatory cytokines, oxidative stress and changes in muscular and physical performances of healthy smokers. However, these parameters have not yet been evaluated simultaneously in previous studies. The participants of this study were healthy males divided into two groups: smokers (n=20) and non-smokers (n=20). Inflammation was evaluated by measuring plasma levels of the cytokines IL-10, IL-6 e TNF-α, and of the soluble receptors sTNFR1 and sTNFR2. Oxidative stress was evaluated by determination of thiobarbituric acid reactive substances (TBARS) plasma levels, total antioxidant capacity of plasma and erythrocytes activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase. Muscular performance was evaluated by measuring the peak torque of knee flexors and extensors, and by determining the total work of the knee extensors. Physical performance was assessed by measuring the peak oxygen uptake (VO2 peak), the maximum heart rate (HRmax) and the walking distance in the shuttle walking test. Smokers showed an increase in the levels of the sTNFR1 and TBARS and a decrease in the total antioxidant capacity of plasma, in the catalase activity and in the total work (P<0.05). IL-6, IL-10, sTNFR2, SOD, peak torque, VO2 peak, HRmax and walking distance were similar between groups. Smokers presented increased oxidative stress and skeletal muscle dysfunction, demonstrating that the changes in molecular and muscular parameters occur simultaneously in healthy smokers.

Efeitos de diferentes tempos de extração no teor e composição química do óleo essencial de folhas de pariparoba [Pothomorphe umbellata (L. ) Miq. ] / Effects of time of extraction in the yield and chemical composition of the essential oil of pariparoba leaves [Pothomorphe umbellata (L. Miq. ]

O presente trabalho visou avaliar a influência de diferentes tempos de extração no teor e composição química do óleo essencial da espécie Pothomorphe umbellata. Folhas de pariparoba foram coletadas em Cajamar - SP, no mês de junho de 2006. O delineamento experimental adotado foi inteiramente casualizado, com seis tempos de extração (90, 120, 150, 180, 210 e 240 minutos) e 4 repetições. A extração do óleo essencial foi realizada por hidrodestilação e a análise química em CG-EM. O tempo de 180 minutos proporcionou maior rendimento do óleo essencial (0,42%), enquanto a composição química não foi influenciada pelos diferentes tempos de destilação. As principais substâncias identificadas foram: D-germacreno (65,5%), alfa-selineno (9,7%), trans-cariofileno (7,5%), e espatulenol (6,58%). Conclui-se que o tempo de extração afeta diretamente o rendimento e a proporção das substâncias químicas, recomendando-se a extração em até 180 minutos. .

The present work aimed to evaluate the influence of different times of extraction in the yield and chemical composition of the essential oil of "pariparoba" (Pothomorphe umbellate). Leaves of "pariparoba" were collected in the municipal district of Cajamar - state of São Paulo, Brazil, in June 2006. The adopted experimental design was completely randomized, with six times of extraction (90, 120, 150, 180, 210, and 240 minutes) and 4 repetitions. The extraction of the essential oil was accomplished by hydrodistillation, and the chemical analysis was performed in GC-MS. The time of extraction of 180 minutes provided greater yield of the essential oil (0.42%), and its chemical composition was not influenced by the different times of hydrodistillation. The main substances showed are D-germacrene (65.5%), alpha-selinene (9.7%), trans-caryophyllene (7.5%) and spathulenol (6.58%). The results of this work showed that the time of extraction affects the yield and the proportion of the chemical substances and it is recommended the extraction in up to 180 minutes.