FIGURE 1.

Baicalin accelerates mammary development during puberty and pregnancy. (A) Illustration of the baicalin stimulation strategy using C57BL/6 mice from puberty to adulthood. The mice were treated with baicalin at the start of puberty, when the mice were 3 weeks old. The mammary glands were harvested from 5-, 6-, and 9-week-old mice. (B) The chemical structure of baicalin. (C) Wholemount carmine staining (red) of mammary glands isolated from 3- to 9-week-old female mice. The data represent three independent experiments. (D) Quantification of duct elongation indicates that baicalin accelerates the elongation of mammary gland ducts at 5 and 6 weeks, but not at 9 weeks. Student’s t-test: **P < 0.01; *P < 0.05; ns, not significant. (E) Illustration of the baicalin stimulation strategy using C57BL/6 mice during pregnancy. To study the role of baicalin in pregnancy, pregnant 8-week-old mice were treated with baicalin at day 0.5 of pregnancy (P0.5d) every day until sample collection. The mammary glands were harvested at P5.5d, P10.5d, and P15.5d. (F) Wholemount carmine staining (red) of mammary glands isolated from pregnant female mice. The black box indicates the focal structure. The data represent three independent experiments. (G) Quantification of alveolar cells indicates that baicalin increases the formation of alveolar cells at P5.5d, P10.5d, and P15.5d. Student’s t-test: ***P < 0.001; ns, not significant. (H) Images of sections from pregnant mice showing milk secretion. Scale bar, 50 μm. (I) Quantification of milk secretion indicates that baicalin can induce the production of milk at P5.5d, but not at P10.5d and P15.5d. Student’s t-test: * P < 0.05; ns, not significant.