Subchronic Toxicity Assessment of Phytolacca americanaL. (Phytolaccaceae) in F344 Rats

Phytolacca americanaL. is traditionally used in Korea, Japan, and China as a diuretic, antibacterial, antiviral, anticancer, and anti-inflammatory agent, and also in the treatment of hepatitis B, psoriasis, edema, and rheumatism. In this study, we evaluated the subchronic toxicity of an aqueous extract of P. americana(PAAE) in male and female F344 rats. The rats were orally administered PAAE (0, 500, 1000, and 2000 mg/kg body weight) once daily for 13 weeks. Mortality rate, body weight, food consumption, and organ weights were measured and assessed. Additionally, ophthalmological, hematological, and histopathological parameters were evaluated. Urinalysis and necropsy were also performed. The clinical chemistry values for potassium in the treated female groups (500, 1000, and 2000 mg/kg/ body weight/day) were higher than those in the control. Further, the relative weights of the kidneys in the treated female groups (1000 and 2000 mg/kg/ body weight/day) were higher than those in the control. However, these changes were not consistent in either sex, and no abnormalities were found in the corresponding pathological findings. Thus the results showed no adverse effects in all the parameters assessed. The findings show that after 13 weeks of treatment, the “no-observed-adverse-effect level” of PAAE is 2000 mg/kg body weight in both male and female F344 rats under the experimental conditions applied. Although treatment-related adverse effects were not seen, potassium-level changes in the blood should be examined to establish the safety profile of PAAE after long-term treatment.