Histological changes in the jejunum and heart mitochondrial ultrastructure. Mice were treated with 4 ml/kg of XBJ (HSXBJ group) or 0.9% saline (HS group), followed by heat insults. (A) Tissue samples from jejunum were stained with H&E. Scale bar, 10 μm. (B) Representative electron micrographs of the heart showing mitochondrial structure (arrows). Scale bar, 500 nm.