Rescue effects of Se-enriched rice on physiological and biochemical characteristics in cadmium poisoning mice.

Cadmium (Cd) is an element injurious for human health and is possibly toxic to organisms at minor concentrations. While some of other trace metallic elements have antagonistic features to it. One of them is the interaction between selenium (Se) and Cd in plant different organs. Literature review disclosed that the intake of Se to some extent can reduce the accumulation of Cd in plants, while the research on of trace metallic elements (Cd) and Se-enriched food (rice) in the living body has rarely been reported. This study intended to explore whether there was a mitigating effect of Se-enriched rice on mice poisoned with Cd. A mouse model of low-dose and high-dose Cd poisoning was established (supplemented with cadmium chloride(CdCl2·2½H20)), followed by feeding two groups (1) Se-enriched rice and (2) setting an equal amount of inorganic Se group. After that, the impact of Se-enriched rice on the antioxidant activity was evaluated. The Se-enriched diet enhanced the total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and enzyme activities of GSH peroxidase (GSH-Px) in mice livers and kidney whereas significantly decreased the malondialdehyde (MDA) contents. Moreover, the degree of physiological damage in mice with low cadmium poisoning was significantly alleviated, and the expression of antioxidant genes (Nrf-2, GPX1, TrxR2, TNF-2) was increased. In conclusion, the Se-enriched diet has a positive effect on the biological effects in mice, and it can be used as a daily diet to resist damage to the body's low Cd state and support enzymatic antioxidant systems by eliminating oxidative injury.

Quick selenium accumulation in the selenium-rich rice and its physiological responses in changing selenium environments.

BACKGROUND: The element selenium (Se) deficiency is thought to be a global human health problem, which could disperse by daily-supplement from Se-rich food. Increasing the accumulation of Se in rice grain is an approach matched to these nutrient demands. Nonetheless, Se is shown to be essential but also toxic to plants, with a narrow margin between deficiency and toxicity. Notably, the regulatory mechanism balancing the accumulation and tolerance of Se in Se-rich rice plants remains unknown. RESULTS: In this study, we investigated the phenotypical, physiological, and biochemical alterations of Se-rich rice in the exposure to a variety of Se applications. Results showed that the Se-rich rice was able to accumulate more abundance of Se from the root under a low Se environment comparing to the Se-free rice. Besides, excessive Se led to phytotoxic effects on Se-rich rice plants by inducing chlorosis and dwarfness, decreasing the contents of antioxidant, and exacerbating oxidative stresses. Furthermore, both phosphate transporter OsPT2 and sulfate transporters OsSultr1;2 may contribute to the uptake of selenate in rice. CONCLUSIONS: Se-rich red rice is more sensitive to exogenous application of Se, while and the most effective application of Se in roots of Se-rich rice was reached in 20 µM. Our findings present a direct way to evaluate the toxic effects of Se-rich rice in the Se contaminated field. Conclusively, some long-term field trial strategies are suggested to be included in the evaluation of risks and benefits within various field managements.