Edaravone Guards Dopamine Neurons Figure 4. Anti-apoptosis effects of Edaravone on Rotenone-induced animals. Bcl-XL and Bax immunostaining of the SNc from all groups five weeks after behavioral test (10 from ROT-group, 8 from Eda-group and 6 from Veh-group). (A),(B) and (C), Bcl-XL expression in Rot-, Eda- and Veh- group respectively; (D),(E) and (F), immunohistostaining of Bax in all these three groups; (G) quantitative analysis of Bcl-XL and Bax expression in all these three groups, respectively. (Scale bars = 20 mm, *P,0.05 as compared to Rot-group). doi:10.1371/journal.pone.0020677.g004 Edaravone prevented rotenone-induced toxicity in peripheral organs No animals died spontaneously within five weeks of the systemic rotenone administration (2.0 mg/kg/day). There were no pathological changes observed in the peripheral organs of Eda-group and Veh-group rats. However, significant pathological changes were observed in the liver, kidney, lung, and spleen, while there was no obvious change in the heart or stomach in Rot-group rats. In Rot-group, neutrophilic infiltration were detected in the lung (Fig. 7A), while the alveolar walls of the Eda-group and Veh-group rats were thin and delicate (Fig. 7E). In the liver, neutrophil infiltration in the periportal areas, the expansion of central veins and bile ducts were observed in the Rot-group (Fig. 7B), but they were intact in the Eda-group and Veh-group (Fig. 7F). In the kidney, the number of red blood cells increased in the renal glomeruli (Fig. 7C) and renal medulla (Fig. 7D), while few red blood cells were seen in the renal glomeruli of Eda-group and Veh-group (Fig. 7G,H). In the spleen, hemorrhage and hemosiderin deposition were observed in the Rot-group (Fig. 7I), while white pulp was noted in the spleen in Eda- group and Veh-group animals (Fig. 7J). Rotenone exerted little influence on the heart (Fig. 7K) and stomach (Fig. 7L) in Rot-group rats. Edaravone prohibited rotenone-induced body weight loss in animals Our data showed the body weight of Rot-group animals and Veh-group animals were significantly different at all time points except on day 0 (P,0.05, Figure S3). However, there was no significantly difference between the body weight of Eda-group animals and Veh-group animals in the whole period of 5 weeks (Figure S3). Moreover, no animals developed constipation (data not shown). However, stool frequency was transiently decreased in rotenone-treated rats during the first 12 days of rotenone exposure and then recovered to control values, which could be associated with the body weight loss of these rats during the first 12 days of rotenone administration. PLoS ONE | www.plosone.org 6 June 2011 | Volume 6 | Issue 6 | e20677