AIMS: In this study, we investigated the effects of mitragynine on dopamine (DA) level and dopamine transporter (DAT) expression from the rat's frontal cortex.
METHODS: DA level was recorded in the brain samples of animals treated with acute or repeated exposure for 4 consecutive days with either vehicle or mitragynine (1 and 30 mg/kg) using electrochemical sensor. Animals were then decapitated and the brain regions were removed, snap-frozen in liquid nitrogen and immediately stored at -80 °C. DA level was quantified using Enzyme linked immunosorbent assay (ELISA) kits and DAT gene expression was determined using quantitative real time polymerase chain reaction (RT-qPCR).
RESULTS/OUTCOME: Mitragynine (1 and 30 mg/kg) did not increase DA release following acute treatment, however, after repeated exposure at day 4, mitragynine significantly and dose dependently increased DA release in the frontal cortex. In this study, we also observed a significant increase in DAT mRNA expression at day 4 in group treated with mitragynine (30 mg/kg).
CONCLUSION/INTERPRETATION: Data from this study indicates that mitragynine significantly increased DA release when administered repeatedly, increased in DAT mRNA expression with the highest tested dose (30 mg/kg). Therefore, the rewarding effects observed after mitragynine administration could be due to its ability to increase DA content in certain areas of the brain especially the frontal cortex.
METHODS: This was a pilot prospective observational study involving 12 pregnant Malay women without any endocrine disorders and on neither antibiotics nor probiotics. Demographic details and anthropometric measurements were obtained, and the faecal 16S ribosomal ribonucleic acid (rRNA) metagenome microbiota of the first and third trimesters (T1 and T3) were analysed. Univariate and multivariate statistics, partial least squares discriminant analysis (PLSDA) and Kendall rank correlation testing were used to identify key genera and associations with pregnancy trimester and body mass index (BMI).
RESULTS: The most abundant phyla were Bacteroidetes, Firmicutes, Proteobacteria and Actinobacteria, with significant differences in composition at the genus level demonstrated between T1 and T3. Sequencing showed a statistically significant difference in beta diversity between normal and abnormal BMI at all taxonomic ranks (R 2 = 0.60; Q 2 = 0.23) and genus levels (R 2 = 0.57; Q 2 = 0.37). The relative abundances of Akkermansia (P < 0.05; false discovery rate [FDR] < 0.05), Olsenella (P < 0.05; FDR < 0.05) and Oscillospira (P < 0.05; FDR < 0.05) were found to be significantly higher in normal BMI cases by 2.4, 3.4 and 3.1 times, respectively.
CONCLUSION: Three genera (Akkermansia, Olsenella and Oscillospira) were correlated with normal BMI during pregnancy. All three could be promising biotherapeutic targets in body weight regulation during pregnancy, subsequently reducing complications associated with higher BMI.
METHODS: A cross-sectional study among 15,639 Malaysian adult males aged 18 years and above was conducted using proportional to size stratified sampling method. The socio-demographic variables examined were level of education, occupation, marital status, residential area, age group and monthly household income.
RESULTS: The prevalence of smoking among adult males in Malaysia was 46.5% (95% CI: 45.5-47.4%), which was 3% lower than a decade ago. Mean age of smoking initiation was 18.3 years, and mean number of cigarettes smoked daily was 11.3. Prevalence of smoking was highest among the Malays (55.9%) and those aged 21-30 years (59.3%). Smoking was significantly associated with level of education (no education OR 2.09 95% CI (1.67-2.60), primary school OR 1.95, 95% CI (1.65-2.30), secondary school OR 1.88, 95% CI (1.63-2.11), with tertiary education as the reference group). Marital status (divorce OR 1.67, 95% CI (1.22-2.28), with married as the reference group), ethnicity (Malay, OR 2.29, 95% CI ( 1.98-2.66; Chinese OR 1.23 95% CI (1.05-1.91), Other Bumis OR 1.75, 95% CI (1.46-2.10, others OR 1.48 95% CI (1.15-1.91), with Indian as the reference group), age group (18-20 years OR 2.36, 95% CI (1.90-2.94); 20-29 years OR 3.31 , 95% CI 2.82-3.89; 31-40 years OR 2.85 , 95% CI ( 2.47-3.28); 41-50 years OR 1.93, 95% CI (1.69-2.20) ; 51-60 years OR 1.32, 95% CI (1.15-1.51), with 60 year-old and above as the reference group) and residential area (rural OR 1.12 , 95% CI ( 1.03-1.22)) urban as reference.
CONCLUSION: The prevalence of smoking among Malaysian males remained high in spite of several population interventions over the past decade. Tobacco will likely remain a primary cause of premature mortality and morbidity in Malaysia. Continuous and more comprehensive anti-smoking policy measures are needed in order to further prevent the increasing prevalence of smoking among Malaysian men, particularly those who are younger, of Malay ethnicity, less educated, reside in rural residential area and with lower socio-economic status.