Cadmium alters whole animal ionome and promotes the re-distribution of iron in intestinal cells of Caenorhabditis elegans.

The chronic exposure of humans to the toxic metal cadmium (Cd), either occupational or from food and air, causes various diseases, including neurodegenerative conditions, dysfunction of vital organs, and cancer. While the toxicology of Cd and its effect on the homeostasis of biologically relevant elements is increasingly recognized, the spatial distribution of Cd and other elements in Cd toxicity-caused diseases is still poorly understood. Here, we use Caenorhabditis elegans as a non-mammalian multicellular model system to determine the distribution of Cd at the tissue and cellular resolution and its effect on the internal levels and the distribution of biologically relevant elements. Using inductively coupled plasma-mass spectrophotometry (ICP-MS), we show that exposure of worms to Cd not only led to its internal accumulation but also significantly altered the C. elegans ionome. Specifically, Cd treatment was associated with increased levels of toxic elements such as arsenic (As) and rubidium (Rb) and a decreased accumulation of essential elements such as zinc (Zn), copper (Cu), manganese (Mn), calcium (Ca), cobalt (Co) and, depending on the Cd-concentration used in the assay, iron (Fe). We regarded these changes as an ionomic signature of Cd toxicity in C. elegans. We also show that supplementing nematode growth medium with Zn but not Cu, rescues Cd toxicity and that mutant worms lacking Zn transporters CDF-1 or SUR-7, or both are more sensitive to Cd toxicity. Finally, using synchrotron X-Ray fluorescence Microscopy (XRF), we showed that Cd significantly alters the spatial distribution of mineral elements. The effect of Cd on the distribution of Fe was particularly striking: while Fe was evenly distributed in intestinal cells of worms grown without Cd, in the presence of Cd, Fe, and Cd co-localized in punctum-like structures in the intestinal cells. Together, this study advances our understanding of the effect of Cd on the accumulation and distribution of biologically relevant elements. Considering that C. elegans possesses the principal tissues and cell types as humans, our data may have important implications for future therapeutic developments aiming to alleviate Cd-related pathologies in humans.

HPTLC Studies, in silico Docking Studies, and Pharmacological Evaluation of Elaeocarpus ganitrus as a Gastroprotective Agent.

OBJECTIVES: Elaeocarpus ganitrus, a member of the Eleocarpaceae family, is valued in Hinduism and Ayurveda, and is frequently used as a remedy for a variety of illnesses. The plant is reputed to treat a number of stomach issues. The purpose of the study was to produce high-quality scientific data regarding gastroprotective behavior, docking experiments with cholinergic receptors, and HPTLC (with lupeol and ursolic acid). To develop the mechanism of herbal extracts, in vitro anticholinergic and antihistaminic activities were evaluated. Different leaf extracts were treated with various reagents to determine the presence of various metabolites. An examination of the histopathology was conducted to determine the full impact of the extract. METHODS: Methanolic extract was chosen for HPTLC investigations after extraction with various solvents. A mobile phase of toluene, ethylacetate, and formic acid (8:2:0.1) was chosen. Molecular docking was utilized to examine how ursolic acid and lupeol are bound to cholinergic receptors (M3). Different extracts (aqueous and ethanolic) were tested for their ability to provide gastroprotection in Wistar rats at different doses (200 and 400 mg/kg). RESULTS: Phytochemical analysis of different extracts showed the presence of different primary and secondary metabolites. HPTLC data showed the presence of both standards. Docking studies exhibited very good interactions with the M3 receptor. Pharmacological studies revealed that extract-treated groups significantly reduced the ulcer index in all of the models mentioned above. The histopathological analysis clearly supports the biochemical studies, which were conducted utilizing various doses and found to be effective in a dose-dependent manner. The in vitro analysis proved that the abovementioned extracts may act as antagonists of acetylcholine and histamine. CONCLUSION: The data obtained would be valuable for the production of the monograph of the plant and conducting concept-related clinical studies in the future. More investigation is required since the gathered scientific data may lead to new research opportunities.

Zinc Oxide Nanoparticle Induces Microglial Death by NADPH-Oxidase-Independent Reactive Oxygen Species as well as Energy Depletion.

Zinc oxide nanoparticle (ZnO-NP) is one of the most widely used engineered nanoparticles. Upon exposure, nanoparticle can eventually reach the brain through various routes, interact with different brain cells, and alter their activity. Microglia is the fastest glial cell to respond to any toxic insult. Nanoparticle exposure can activate microglia and induce neuroinflammation. Simultaneous to activation, microglial death can exacerbate the scenario. Therefore, we focused on studying the effect of ZnO-NP on microglia and finding out the pathway involved in the microglial death. The present study showed that the 24 h inhibitory concentration 50 (IC50) of ZnO-NP for microglia is 6.6 µg/ml. Early events following ZnO-NP exposure involved increase in intracellular calcium level as well as reactive oxygen species (ROS). Neither of NADPH oxidase inhibitors, apocynin, (APO) and diphenyleneiodonium chloride (DPIC) were able to reduce the ROS level and rescue microglia from ZnO-NP toxicity. In contrary, N-acetyl cysteine (NAC) showed opposite effect. Exogenous supplementation of superoxide dismutase (SOD) reduced ROS significantly even beyond control level but partially rescued microglial viability. Interestingly, pyruvate supplementation rescued microglia near to control level. Following 10 h of ZnO-NP exposure, intracellular ATP level was measured to be almost 50 % to the control. ZnO-NP-induced ROS as well as ATP depletion both disturbed mitochondrial membrane potential and subsequently triggered the apoptotic pathway. The level of apoptosis-inducing proteins was measured by western blot analysis and found to be upregulated. Taken together, we have deciphered that ZnO-NP induced microglial apoptosis by NADPH oxidase-independent ROS as well as ATP depletion.

Hijacking microglial glutathione by inorganic arsenic impels bystander death of immature neurons through extracellular cystine/glutamate imbalance.

Arsenic-induced altered microglial activity leads to neuronal death, but the causative mechanism remains unclear. The present study showed, arsenic-exposed (10 µM) microglial (N9) culture supernatant induced bystander death of neuro-2a (N2a), which was further validated with primary microglia and immature neuronal cultures. Results indicated that arsenic-induced GSH synthesis by N9 unfavorably modified the extracellular milieu for N2a by lowering cystine and increasing glutamate concentration. Similar result was observed in N9-N2a co-culture. Co-exposure of arsenic and 250 µM glutamate, less than the level (265 µM) detected in arsenic-exposed N9 culture supernatant, compromised N2a viability which was rescued by cystine supplementation. Therefore, microglia executes bystander N2a death by competitive inhibition of system Xc(-) (xCT) through extracellular cystine/glutamate imbalance. We confirmed the role of xCT in mediating bystander N2a death by siRNA inhibition studies. Ex-vivo primary microglia culture supernatant from gestationally exposed mice measured to contain lower cystine and higher glutamate compared to control and N-acetyl cysteine co-treated group. Immunofluorescence staining of brain cryosections from treated group showed more dead immature neurons with no such effect on microglia. Collectively, we showed, in presence of arsenic microglia alters cystine/glutamate balance through xCT in extracellular milieu leading to bystander death of immature neurons.