Effects of MgIG treatment on apoptosis detected by TUNEL staining in (A) liver and (B) heart tissues. Representative images of apoptotic cells (marked by black arrows) and graphs of the proportion of positive cells in each group are presented. Scale bar=50 µm; magnification, ×400. Data are presented the mean ± standard error of the mean. **P<0.01 vs. the DOX group; ##P<0.01 vs. the control group. MgIG, magnesium isoglycyrrhizinate; TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling; DOX, doxorubicin; L-MgIG, low-dose MgIG; M-MgIG, medium-dose MgIG; H-MgIG, high-dose MgIG.