Armeniacae semen (AS) has been considered a toxic herb in the Korean medicine as it contains hydrogen cyanide and amygdalin, especially in its endocarp. Therefore, prebrewed AS that is devoid of endocarp has been traditionally used. In the present study, amygdalin content of the prebrewed AS was significantly lower (2.73 ± 0.32 μg/ml; p < 0.01) than the content in the extract that contained the endocarps (28.50 ± 6.71 μg/ml); amygdalin content corresponded to 10% of the extract in the present study. Because of single oral dose toxicity of prebrewed AS according to the recommendation of Korea Food and Drug Administration Guidelines (2009-116, 2009), which was based on single oral dose toxicity study of prebrewed AS, mortality due to toxic principles was significantly reduced. In this study, 2,000 mg/kg of prebrewed AS led to death of 1 female rat and 1 male rat at the end of 2 hr of administration. Based on these results, the 50% lethal dose in both male and female rats was determined to be 9279.5 mg/kg. Seizure, loss of locomotion, and increases in respiration and heart rate were observed as prebrewed AS treatment-related toxicological signs; these signs were restrictedly manifested in the prebrewed AS (2,000 mg/kg)-treated rats. In addition, no changes were observed in body weight, organ weight, gross features, and histopathological parameters with 2,000 mg/kg of AS in both male and female rats. These findings serve as direct evidence that amygdalin in AS is the toxic principle, which can be reduced by the traditional prebrewing method involving the exclusion of endocarp.

Objectives : This study was to evaluate the single dose toxicity of Persicae Semen (PS) in ICR mice. Methods : Aqueous extracts of PS (Yield = 18.60%) were administered as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) guidelines (2009-116, 2009). Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 12 principle organs were examined. Results : Amygdalin contents in PS aqueous extracts were detected as 32.50±5.96 µg/ml. We could not find any PS extracts treatment related mortalities, clinical signs, changes on the body and organ weights, gross and histopathological observations up to 2,000 mg/kg in both female and male mice, except for transient and slight loss of locomotion detected in female and male mice treated with 2,000 mg/kg. In addition, pharmacological immunomodulatory effects related findings were also demonstrated in 2,000mg/kg treated female and male mice as hypertrophy and hyperplasia of lymphoid cells in the submandibular lymph nodes. Conclusions : Based on the results of this experiment, the approximate lethal dose (ALD) of PS extracts after single oral treatment in female and male mice were considered above 2,000 mg/kg, respectively. It should be carefully used in clinics because the possibilities of respiratory or neurological disorders were observed when administered over 2,000 mg/kg of PS extract related to amygdalin.