Toxicity of antioxidative extract collected from Styela clava tunics in ICR mice

Some polymers and bioactive compounds derived from Styela clava tunic (SCT) have been reported as traditional medicine for the treatment of inflammation, oxidative stress and surgical wounds although there is little scientific evidence of their liver and kidney toxicity. To investigate the toxicity of ethanol extracts of SCT (EtSCT) in the liver and kidney of ICR mice, alterations in related markers including body weight, organ weight, urine composition, liver pathology and kidney pathology were analyzed following oral administration of 50 and 100 mg/kg body weight/day of EtSCT for 14 days. EtSCT showed a high level of free radical scavenging activity for DPPH (93.1%) and NO (16.2%) as well as the presence of 14.8 mg/mL of flavonoids and 36.2 mg/mL of phenolics, while EtSCT treated groups did not show any significant alterations in the body and organ weight, clinical phenotypes, urine parameters or mice mortality when compared with the vehicle treated group. In addition, constant levels of serum biochemical markers including alanine phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum creatinine (CRE) were maintained. Moreover, no specific histopathological features induced by most toxic compounds were observed in liver and kidney sections stained with hematoxilin and eosin. Therefore, the present results indicate that EtSCT with strong antioxidant activity cannot induce any specific toxicity in liver and kidney organs of ICR at doses of 100 mg/kg body weight/day.