Fate of selenium in a Se-enriched region of North China: Translocation, bioaccumulation, source, and health benefits.

There are limited studies on the translocation and bioaccumulation of selenium (Se) in weak alkaline cultivated Se-enriched soil, and the sources and speciation of Se in wheat grains remain unclear. In this study, we measured the Se levels in soils, roots, stems, and wheat grains from Se-enriched cultivated land in Ci County, China, which has a high incidence of esophageal cancer. The Se levels in the roots were higher than those in the soils, indicating that wheat plants bioaccumulated high concentrations of Se from the soil (enrichment coefficient [EC] range from the soil to the root: 0.94-3.29). Redundancy analysis indicated that the bioaccumulated factor, translocation coefficient, and EC were mainly controlled by phosphorus, pH, and Fe2O3 (contribution rates: 37.5%, 19.5%, and 15.9%, respectively). Linear regression analysis revealed that the sources of Se in grains were mainly from the water-soluble fraction (R2 = 0.55, at p < 0.05), the weakly acidic fraction (R2 = 0.84, at p < 0.05), the reducible fraction (R2 = 0.84, at p < 0.05), and the oxidizable fraction (R2 = 0.70, at p < 0.05), as well as from atmospheric deposition (R2 = 0.37, at p < 0.01). There is a significant correlation between the Se from atmospheric deposition and the oxidizable fraction (R2 = 0.62, at p < 0.01) and the residual fraction (R2 = 0.33, at p < 0.01). The contribution of Se input flux from atmospheric deposition was 5.50 g/hm2 for one year. Furthermore, the average content of organic Se in wheat grains was 58.93%. The Se concentrations found in wheat grains were considered beneficial for human health based on a comparison with the Chinese Society of Nutrition standard and worldwide levels. The results of this study will increase the overall knowledge on the theme, which could help prevent and control the harmful effects of undesirable concentrations of Se on human health.

Antibacterial steroidal alkaloids from Holarrhena antidysenteriaca / 中国天然药物

Two new steroidal alkaloids, isoconkuressine and N-formylconessimine, together with 6 known steroidal alkaloids including conkuressine, conessine, isoconessimine, conimine, conarrhimine, and funtudienine, were isolated from the seeds of Holarrhena antidysenteriaca Wall.ex A.DC. Their intrinsic antibacterial activities and synergistic effects with penicillin and vancomycin were analyzed in methicillin sensitive staphylococcus aureus (MSSA) and methicillin resistant staphylococcus aureus (MRSA). Two of the steroidal alkaloids including one new compound (N-formylconessimine) showed potential antibacterial activity and possessed synergistic effects with penicillin and vancomycin, respectively.

Atomoxetine increases histamine release and improves learning deficits in an animal model of attention-deficit hyperactivity disorder: the spontaneously hypertensive rat.

Substantial development in the pharmacological treatment for attention-deficit hyperactivity disorder (ADHD) has been made recently including approval of new non-stimulant agents targeting noradrenergic, histaminergic and dopaminergic systems. Among such, atomoxetine has been widely used, although its mechanism of action is poorly understood. It is known that central nervous system histamine is closely associated with cognition and it was recently shown that both atomoxetine and methylphenidate enhance cortical histamine release in rats. To that end, the aim of our study was to investigate the effect of atomoxetine (2 mg/kg, intraperitoneally) on histamine release using the microdialysis technique in the spontaneously hypertensive rat (SHR), a suitable genetic model for ADHD. Our data confirmed that atomoxetine increases extracellular levels of histamine in the prefrontal cortex, a brain region that is implicated in the pathophysiology of ADHD. Given the tie between histamine neurotransmission and treatment of cognitive dysfunction, we also assessed the effects of atomoxetine on learning and memory as measured by the Morris water maze in SHR. The results indicated that atomoxetine significantly ameliorated performance in the Morris water maze, consistent with its histamine-enhancing profile. In conclusion, the current study provides further support for the notion that the therapeutic effect of atomoxetine could involve activation of histamine neurotransmission within the prefrontal cortex.