Study On The Toxicity Of Sodium Fluoride To Caenorhabditis Elegans

Fluorine is a necessary microelement to human and animals. Appropriate fluorine is beneficial for our health but too much fluorine will induce fluorosis. So it is important to research the damage to organism induced by too much fluorine. To investigate the toxicity of sodium fluoride (NaF) on the nematode Caenorhabditis elegans (C.elegans), the physiological, biochemical and molecular levels of C.elegans were investigated. The adult C.elegans were exposed to different concentrations of NaF (1.6 mg/L,16 mg/L and 160 mg/L) for 24 h. To assess the physiological-level effect, brood size, life span, head thrashes and body bend frequency were investigated. To assess the biochemical-level effect, the detection of free radicals and cell apoptosis were investigated. Related genes expression in C.elegans through real-time polymerase chain reaction (PCR) was investigated as the molecular-level response.On the physiological-level, brood size,life span,head thrashes and body bend frequency all decreased with the concentration of NaF raised. On the biochemical-level, free radicals and cell apoptosis were more and more obvious with the concentration of NaF raised. On the molecular-level, different concentrations of NaF exposure raised the expression of stress-related genes such as hsp16.1, sod-3, ctl-2, dhs-28, gst-1 and cep-1 related to cell apoptosis. These results showed that NaF exposure could induce the multiple biological toxicities to C.elegans and these toxicities of NaF were in the concentration-dependent manner. Besides, it also could be speculated that the mechanism of fluorosis was relevant to the oxidative damage induced by metabolic disorder of free radicals.