Dysfunction of Rice Mitochondrial Membrane Induced by Yb3+

Bidirectional Regulatory Mechanisms of Jaceosidin on Mitochondria Function: Protective Effects of the Permeability Transition and Damage of Membrane Functions

Many natural products could induce apoptosis through mitochondrial pathways. However, direct interactions between natural products and mitochondria have rarely been reported. In this work, the effects and regulatory mechanisms of Jaceosidin on the isolated rat liver mitochondria have been studied. The results of the experiments which by introducing exogenous Ca²⁺ illustrated that Jaceosidin has the protective effects on the structure and function of the isolated mitochondria. These protective effects were related to the chelation of Ca²⁺ with Jaceosidin. Besides, Jaceosidin could scavenge reactive oxygen species produced during electron transport, and weaken the mitochondrial lipid peroxidation rate, which may be attributed to the antioxidant effect of phenolic hydroxyl groups of Jaceosidin. In addition, Jaceosidin has some damage effects on mitochondrial function, such as the inhibition of mitochondrial respiration and the increase of mitochondrial membrane fluidity. These results of this work provided comprehensive information to clarify the mechanisms of Jaceosidin on mitochondria, which may be the bidirectional regulatory mechanisms.

Heavy Rare Earth Elements Affect Sphaerechinus granularis Sea Urchin Early Life Stages by Multiple Toxicity Endpoints

Heavy rare earth elements (HREEs) were tested for adverse effects to early life stages of the sea urchin Sphaerechinus granularis. Embryos were exposed to analytically measured HREE concentrations ranging from 10^-7 to 10^-5 M. No significant developmental defect (DD) increases were observed in embryos exposed to 10^-7 M HREEs, whereas 10^-5 M HREEs resulted in significant DD increase up to 96% for HoCl₃ versus 14% in controls. Embryos exposed to 10^-6 M HREEs showed the highest DD frequency in embryos exposed to 10^-6 M DyCl₃ and HoCl₃. Cytogenetic analysis of HREE-exposed embryos revealed a significant decrease in mitotic activity, with increased mitotic aberrations. When S. granularis sperm were exposed to HREEs, the offspring of sperm exposed to 10^-5 M GdCl₃ and LuCl₃ showed significant DD increases. The results warrant investigations on HREEs in other test systems, and on REE-containing complex mixtures.

Heavy rare earth elements affect early life stages in Paracentrotus lividus and Arbacia lixula sea urchins

BACKGROUND

Heavy rare earth elements (HREEs) have been scarcely studied for their toxicity, in spite of their applications in several technologies. Thus HREEs require timely investigations for their adverse health effects.

METHODS

Paracentrotus lividus and Arbacia lixula embryos and sperm were exposed to trichloride salts of five HREEs (Dy, Ho, Er, Yb and Lu) and to Ce(III) as a light REE (LREE) reference to evaluate: 1) developmental defects (% DD) in HREE-exposed larvae or in the offspring of HREE-exposed sperm; 2) mitotic anomalies; 3) fertilization success; and 4) reactive oxygen species (ROS) formation, and nitric oxide (NO) and malondialdehyde (MDA) levels. Nominal HREE concentrations were confirmed by inductively coupled plasma mass spectrometry (ICP-MS).

RESULTS

HREEs induced concentration-related DD increases in P. lividus and A. lixula larvae, ranging from no significant DD increase at 10^-7M HREEs up to ≅100% DD at 10^-5M HREE. Larvae exposed to 10^-5M Ce(III) resulted in less severe DD rates compared to HREEs. Decreased mitotic activity and increased aberration rates were found in HREE-exposed P. lividus embryos. Significant increases in ROS formation and NO levels were found both in HREE-exposed and in Ce(III) embryos, whereas only Ce(III), but not HREEs resulted in significant increase in MDA levels. Sperm exposure to HREEs (10^-5-10^-4M) resulted in a concentration-related decrease in fertilization success along with increase in offspring damage. These effects were significantly enhanced for Dy(III), Ho(III), Er(III) and Yb(III), compared to Lu(III) and to Ce(III).

CONCLUSION

HREE-associated toxicity affected embryogenesis, fertilization, cytogenetic and redox endpoints showing different toxicities of tested HREEs.