Comparative effects of ascobin and glutathione on copper homeostasis and oxidative stress metabolism in mitigation of copper toxicity in rice.

Copper (Cu) pollution of agricultural land is a major threat to crop production. Exogenous chemical treatment is an easily accessible and rapid approach to remediate metal toxicity, including Cu toxicity in plants. We compared the effects of ascobin (ASC; ascorbic acid:citric acid at 2:1) and glutathione (GSH) in mitigation of Cu toxicity in rice. Plants subjected to Cu stress displayed growth inhibition and biomass reduction, which were connected to reduced levels of chlorophylls, RWC, total phenolic compounds, carotenoids and Mg2+ . Increased accumulation of ROS and malondialdehyde indicated oxidative stress in Cu-stressed plants. However, application of ASC or GSH minimized the inhibitory effects of Cu stress on rice plants by restricting Cu2+ uptake and improving mineral balance, chlorophyll content and RWC. Both ASC and GSH pretreatments reduced levels of ROS and malondialdehyde and improved activities of antioxidant enzymes, suggesting their roles in alleviating oxidative damage. A comparison on the effects of ASC and GSH under Cu stress revealed that ASC was more effective in restricting Cu2+ accumulation (69.5% by ASC and 57.1% by GSH), Ca2+ and Mg2+ homeostasis, protection of photosynthetic pigments and activation of antioxidant defence mechanisms [catalase (110.4%), ascorbate peroxidase (76.5%) and guaiacol peroxidase (39.0%) by ASC, and catalase (58.9%) and ascorbate peroxidase (59.9%) by GSH] in rice than GSH, eventually resulting in better protection of ASC-pretreated plants against Cu stress. In conclusion, although ASC and GSH differed in induction of stress protective mechanisms, both were effective in improving rice performance in response to Cu phytotoxicity.

Secondhand smoke and illness: are mother-child pairs from low socio-economic strata at increased risk in Bangladesh?

To examine: 1) whether exposure to secondhand smoke (SHS) at home is associated with symptoms of self-reported illness among mother-child pairs (MCPs); and 2) the relationship between low socio-economic status and SHS exposure and the role these play as obstacles to the reduction of risk of illness in MCPs. A cross-sectional study was conducted in Rajshahi District, Bangladesh, from May to July 2017. A total of 541 MCPs were interviewed. The prevalence of SHS exposure at home in our sample data was 49.0%. SHS exposure was found to be associated with a higher likelihood of any self-reported rhinitis, any respiratory symptoms and any reproductive health problems among mothers. SHS exposure in children was found to be associated with a higher likelihood of any self-reported rhinitis and food sensitisation, any respiratory symptoms and otitis media. Our findings also suggested that although SHS had an independently adverse effect on MCPs, wealth moderated the likelihood of illness. MCPs who were both poor and exposed to SHS were uniquely disadvantaged in terms of their poor health conditions than MCPs who were wealthier and exposed to SHS. .

Socio-economic inequalities in secondhand smoke exposure at home in the context of mother-child pairs in Bangladesh.

OBJECTIVES: This study aimed to examine socio-economic disparities in mother-child pairs' self-reported and cotinine-measured secondhand smoke (SHS) exposure at home. STUDY DESIGN: This is a cross-sectional study. METHODS: This study was conducted in the Rajshahi district of Bangladesh from May to July 2017. A total of 541 mother-child pairs were interviewed for self-reported measured SHS; cotinine-measured saliva test was performed on 263 mothers and 236 children. Mother-child pairs' SHS exposure at home was the outcome of interest. RESULTS: Overall self-reported prevalence of SHS exposure at home was 49.0%. Self-reported SHS exposure among mothers (50.2%) and children (51.3%) were lower than the prevalence rate of cotinine-measured exposure for mothers (60.5%) and their children (58.9%). Maternal rich bands of wealth were found to be associated with lower likelihood of self-reported (adjusted odds ratio [AOR] = 0.59, 95% confidence interval [CI] = 0.35-0.99) and cotinine-measured SHS exposure among mothers (AOR = 0.17, 95% CI = 0.08-0.37). Maternal rich bands of wealth were also found to be associated with lower likelihood of cotinine-measured SHS exposure among children (AOR = 0.11, 95% CI = 0.07-0.26). CONCLUSIONS: Socio-economic inequalities exist in exposure to SHS at home. Interventional approaches aimed at reducing SHS at home are urgently needed at public health and healthcare service level, with special focus given to the socioeconomically disadvantaged groups.