Potential neurobehavioral toxicity of sulfur in mice

Sulfur is one of the crucial elements in animal nutrition and has an influential role in forming amino acids. It is a common toxic element and does not significantly threaten human and animal health. The current study aimed to examine the potential neurobehavioral toxicity of sulfur in mice by studying its effects on animal behavior and locomotor activity. The 24h median lethal dose- (LD50) of sulfur in mice, as determined by the up-and-down method was 33.22 g/kg; orally, whereas its approximate lethal dose (ALD) was 36 g/kg, within 24 h. Signs of sulfur poisoning in mice were depression, gasping, Straub tail, Piloerection, tremor, dyspnea, muscle fasciculation, and convulsions followed by death. Sulfur at 4 and 8 g/kg doses, after 4 and 24 h, caused significant changes in the neurobehavioral performance in mice. It appeared as a significant decrease in motor activity within the open-field test (number of crossed squares and number of rearing within 3 minutes), with prolongation and increase in the time required to complete the negative geotaxis test with a significant reduction in the number of head pocking and a slight decrease in the swimming test scores. Repeated administration of sulfur at doses of 1, 2, and 4 g/kg; for 7 and 14 consecutive days also led to significant decrease in the motor activity inside the open-field with a prolongation of the time required to complete the negative geotaxis with a significant reduction in the number of head pockings and a slight reduction in the swimming endurance test. Using a pharmacological challenge with xylazine and ketamine, sulfur induced a delay and prolongation in the onset of time of sleep and shortened the sleep duration. This study concludes that sulfur, despite its low toxicity, is a potential neurobehavioral toxicant