Assessment of sub-chronic oral toxicity of Nityanand Rasa: An ayurvedic herbo-metallic formulation

Ethnopharmacological relevance: Nityananda Rasa (NR) is an ayurvedic herbo-metallic formulation used to treat gout, obesity, hypothyroidism, elephantiasis, and other diseases. However, its safety is a concern owing to the use of heavy metals like mercury and arsenic. Aim of the study: To study the sub-chronic oral toxicity of NR on albino wistar rats for safety evaluation. Materials and methods: The male and female albino wistar rats were administered a daily dose of 30 (low), 300 (medium) and 600 (high) mg/kg BW/day of NR for 90-day period. The body weight and feed consumption were monitored once a week. After 90 days, blood and vital organs were harvested for genotoxicity, hematology, biochemistry, histopathology, gene expression and the biodistribution analysis. Results: There was no mortality or severe behavioural changes observed in rats. Significant changes in biochemical enzyme levels were seen at medium and high doses of NR i. e. 300 and 600 mg/kg BW/day respectively. No hematological changes were observed. Mild histopathological changes seen at high dose of NR which were found in concurrence with the biochemical alterations in liver and brain. There was mild genotoxicity and no detectable level of mercury but significant arsenic level in blood at high dose. Gene expression was mildly affected. Conclusions: NR induced moderate toxic effects at high dose but can be considered safe at therapeutic doses.