Smoking is a learned behavior during adolescence, and it is found predominantly among male adolescents in Malaysia. Our study aimed to investigate the prevalence and predictive factors of current cigarette smoking among school-going male adolescents in Malaysia. Data were derived from the National Health and Morbidity Survey: Adolescent Health Survey 2017, a cross-sectional study that utilized a 2-stage stratified cluster sampling to select a nationally representative sample of school-going adolescents in Malaysia (n = 27 497). Multiple logistic regression analysis was performed to identify factors associated with current cigarette smoking among male adolescents in Malaysia. Male adolescents aged 16 to 17 years (adjusted odds ratio [AOR] = 1.55; 95% confidence interval [CI] = 1.41-1.70), current illicit drug users (AOR = 8.14; 95% CI = 6.37-10.41), current alcohol users (AOR = 1.92; 95% CI = 1.65-2.23), those from rural schools (AOR = 1.60; 95% CI = 1.46-1.76), those whose parents were widowed/divorced/separated (AOR = 1.37; 95% CI = 1.21-1.55), and those whose parents/guardians were tobacco product users (AOR = 3.47; 95% CI = 2.33-5.16) were more likely to be current cigarette smokers. Tobacco control strategies should be aimed at both adolescents at risk and at promoting parental smoking cessation.
Seven new tropane alkaloids, including five monomeric (1-5), one dimeric (6), and one trimeric (7) 3α-nortropane ester, along with two known monomeric nortropane alkaloids (8 and 9), were isolated from the leaves and bark of Pellacalyx saccardianus. Their structures, including the absolute configuration of the enantiomeric pair of (±)-6, were elucidated by comprehensive spectroscopic analyses. Alkaloids 6 and 7 showed cytotoxicity toward human pancreatic cancer cell lines (AsPC-1, BxPC3, PANC-1, and SW1990). Alkaloids 1, 4, and 9 induced a smooth muscle relaxation effect comparable to that of atropine (Emax 106.1 ± 7.5%, 97.0 ± 5.2%, 100.9 ± 1.4%, 111.7 ± 1.7%, respectively) on isolated rat tracheal rings.
Precursor mRNA (pre-mRNA) splicing is catalyzed by a large ribonucleoprotein complex known as the spliceosome. Numerous studies have indicated that aberrant splicing patterns or mutations in spliceosome components, including the splicing factor 3b subunit 1 (SF3B1), are associated with hallmark cancer phenotypes. This has led to the identification and development of small molecules with spliceosome-modulating activity as potential anticancer agents. Jerantinine A (JA) is a novel indole alkaloid which displays potent anti-proliferative activities against human cancer cell lines by inhibiting tubulin polymerization and inducing G2/M cell cycle arrest. Using a combined pooled-genome wide shRNA library screen and global proteomic profiling, we showed that JA targets the spliceosome by up-regulating SF3B1 and SF3B3 protein in breast cancer cells. Notably, JA induced significant tumor-specific cell death and a significant increase in unspliced pre-mRNAs. In contrast, depletion of endogenous SF3B1 abrogated the apoptotic effects, but not the G2/M cell cycle arrest induced by JA. Further analyses showed that JA stabilizes endogenous SF3B1 protein in breast cancer cells and induced dissociation of the protein from the nucleosome complex. Together, these results demonstrate that JA exerts its antitumor activity by targeting SF3B1 and SF3B3 in addition to its reported targeting of tubulin polymerization.
Smoking cessation significantly reduces risk of smoking-related diseases and mortality. This study aims to determine the prevalence and factors associated with attempts to quit and smoking cessation among adult current smokers in Malaysia. Data from the National E-Cigarette Survey 2016 were analyzed. Forty nine percent of current smokers had attempted to quit at least once in the past 12 months and 31.4% of the respondents were former smokers. Multivariable analysis revealed that current smokers with low nicotine addiction and aged below 45 years were more likely to attempt to quit smoking. Being married, older age group, and having tertiary education were significantly associated with smoking cessation. Only half of the current smokers ever attempted to quit smoking and only a third of smokers quit. Stronger tobacco control policies are needed in Malaysia to encourage more smokers to quit smoking. Improved access to cessation support for underprivileged smokers is also needed.
OBJECTIVES: Secondhand smoke (SHS) has been associated with increased morbidity and mortality. Therefore, the aims of the paper are to assess SHS exposure among non-smoking adults in Malaysia attending various smoking-restricted and non-restricted public areas according to the Control of Tobacco Product Regulations (CTPR) as well as its relationship with various sociodemographic variables.
DESIGN: Data were extracted from a cross-sectional study, the Global Adults Tobacco Survey (GATS) 2011 which involved 3269 non-smokers in Malaysia. Data was obtained through face-to-face interviews using a validated pre-tested questionnaire. Factors associated with exposure to SHS were identified via multivariable analysis.
RESULTS: The study revealed that almost two-thirds of respondents were exposed to SHS in at least one public area in the past 1 month, with a significantly higher exposure among males (70.6%), those with higher educational attainment (81.4%) and higher income (quintile 1%-73.9%). Besides, the exposure to SHS was almost four times higher in non-restricted areas compared with restricted areas under the CTPR (81.9% vs 22.9). Multivariable analysis revealed that males and younger adults at non-restricted areas were more likely to be exposed to SHS while no significant associated factors of SHS exposure was observed in restricted areas.
CONCLUSIONS: The study revealed the prevalence of SHS exposure was higher among Malaysian adults. Although smoke-free laws offer protection to non-smokers from exposure to SHS, enforcement activities in restricted areas should be enhanced to ensure strict public abidance. In addition, legislation of restricted areas should also be extended to greatly reduce the SHS exposure among non-smokers in Malaysia.
Study name: Global Adults Tobacco Survey (GATS-2011)
The jerantinine family of Aspidosperma indole alkaloids from Tabernaemontana corymbosa are potent microtubule-targeting agents with broad spectrum anticancer activity. The natural supply of these precious metabolites has been significantly disrupted due to the inclusion of T. corymbosa on the endangered list of threatened species by the International Union for Conservation of Nature. This report describes the asymmetric syntheses of (-)-jerantinines A and E from sustainably sourced (-)-tabersonine, using a straight-forward and robust biomimetic approach. Biological investigations of synthetic (-)-jerantinine A, along with molecular modelling and X-ray crystallography studies of the tubulin-(-)-jerantinine B acetate complex, advocate an anticancer mode of action of the jerantinines operating via microtubule disruption resulting from binding at the colchicine site. This work lays the foundation for accessing useful quantities of enantiomerically pure jerantinine alkaloids for future development.