Single Does Oral Toxicity and 4-weeks Repeated Oral Toxicity Studies of Ecklonia cava Extract

Abstract

Ecklonia cava, a species of brown algae, is traditionally used as a foodstuff in Japan and Korea. The phlorotannin components extracted from Ecklonia cava have recently been recognized to possess various biological activities such as antioxidant, anti-inflammatory and anti-carcinogenesis effects. As part of their safety assessment, acute (single dose) and subacute (4-week repeated dose) toxicities were investigated in SD rats using E. cava extracts containing 65% and 20% phlorotannins, respectively. No mortalities or evidence of adverse effects were observed on single oral administration of E. cava extract (65% phlorotannin) at a dose of 2000 mg/kg body weight in SD rats. In a 4-week repeated dose toxicity study, E. cava extract (20% phlorotannin) was orally administrated to SD rats at dose of 0, 222, 667, or 2000 mg/kg/day for 4 weeks. All rats survived until scheduled sacrifice. Compared to the control group, administration of the E. cava extract did not result in any toxicologically significant treatment related changes in clinical observation, body weight gains, ophthalmologic examinations, hematology, coagulation, clinical pathology evaluation and organ weights. Terminal necropsy did not reveal any treatment related gross or histopathology findings. Based on the results of this study, the no-observed-adverse-effect-level (NOAEL) for the E. cava extract was determined as 2000 mg/kg body weight/day, or probably higher dose.