L-DOPA induces iron accumulation in roots of Ipomoea aquatica and Arabidopsis thaliana in a pH-dependent manner.

BACKGROUND: Iron deficiency is the leading cause of anemia worldwide, particularly in countries with predominant plant-based diets. Plants constitute the main source of dietary iron. Increasing their iron concentration could reduce the occurrence of anemia. The water spinach Ipomoea aquatica is consumed as a vegetable throughout Asia and tolerates high iron concentrations making it an attractive candidate for iron biofortification. L-DOPA is an allelopathic molecule secreted by some legumes. L-DOPA can trigger the expression of Fe deficiency-inducible genes, and could potentially be used as a biostimulant to increase Fe concentration. RESULTS: L-DOPA significantly affected root growth of water spinach, and triggered a massive accumulation of Fe in roots. Both effects were exacerbated when L-DOPA was dissolved in KOH, which is surprising given that L-DOPA is less stable at high pH. To check whether a higher pH could indeed increase the bioactivity of L-DOPA, we used Arabidopsis thaliana, which grows at lower pH than water spinach, and subjected the plants to L-DOPA treatments at pH 5.5 and pH 6.0, which are both within the optimal range for Arabidopsis nutrition. At pH 6.0, the root growth of Arabidopsis was more strongly inhibited than at pH 5.5. We found that at higher pH, L-DOPA oxidizes to form a melanin precipitate. CONCLUSIONS: We concluded that the oxidation of L-DOPA that we observed upon solubilization in KOH, or in nutrient solutions at slightly higher pH produces melanin-related molecules that are more potent than L-DOPA itself to trigger the primary root growth inhibition, Fe uptake and root Fe accumulation in water spinach and Arabidopsis.

Physical and psychological stress along with candle fumes induced-cardiopulmonary injury mimicking restaurant kitchen workers.

Restaurant kitchens are work areas where involve strict and hierarchal environments that promote opportunity for bullying and workplace aggression and violence. These physical and psychological stress and fumes ultimately trigger severe occupational stress by disrupting the body's homeostasis that might induce cardiopulmonary injury. The study aimed to investigate the physical and psychological stress and candle fumes on cardiopulmonary injury in an animal model mimicking a restaurant kitchen worker. Social disruption stress (SDR) mice were exposed to scented candle fumes (4.5 h/d, 5 d/wk) in an exposure chamber for 8 weeks. Exposure to burning scented candles failed to reduce serum corticosterone level and increased proinflammatory cytokines levels and NF-ƙB activity in the lung. In addition, burning scented candle fumes synergistically increased SDR-induced serum LDH, CPK, CKMB levels, proinflammatory cytokines production as well as NF-ƙB activation in the lung and heart. Further, cardiac HIF-1α and BNP levels were also increased. We conclude that the physical and psychological stress along with candle fumes might induce cardiopulmonary injury in mice. These results could be extrapolated to restaurant kitchen workers.

A recombinant peroxisome proliferator response element-driven luciferase assay for evaluation of potential environmental obesogens.

A recombinant Huh7-PPRE-Luc cell line for analyzing the peroxisome proliferator response element (PPRE)-driven luciferase activity was established. The cells exhibited a good dose-response induction in PPRE-driven luciferase activity by three subtypes of peroxisome proliferator-activated receptor (PPAR) agonists as well as by a retinoid X receptor agonist, 9-cis-retinoic acid. Among five environmental chemicals tested, benzyl butyl phthalate and bisphenol induced PPRE-driven luciferase activation in Huh7-PPRE-Luc cells and caused adipogenic differentiation of 3T3-L1 cells. This recombinant Huh7-PPRE-Luc cell line would be useful for screening potential environmental obesogens with PPAR activity.