Icariin suppresses tumor growth in vivo.
To determine whether the in vivo antitumor efficiency of icariin
was consistent with its effects in vitro , MDA-MB-231
tumor-bearing mice and 4T1 tumor-bearing mice were treated with icariin
at 20 mg/kg and 40 mg/kg. As shown
in Fig. 6A-C, treatment with icariin at 20 mg/kg
(P <0.01)
or 40 mg/kg (P <0.005) significantly inhibited
MDA-MB-231 tumor growth and weight in a dose-dependent manner in
comparison with the control group. The body weight of the mice did not
present any abnormal variation during the treatment process (Fig. 6D).
Moreover, the results of immunohistochemistry analysis of the tumors
(Fig. 6E) indicated that icariin inhibited the proliferation of nuclear
Ki-67-positive cells, enhanced the expression of cleaved caspase3 to
induce cell apoptosis and downregulated expression level of NF-κB in
tumor sections. Moreover, western-blot analysis of isolated tumors
revealed that icariin enhanced expression level of SIRT6 and inhibited
nuclear expression level of NF-κB p65 (Fig. 6F). In the 4T1
tumor-bearing mouse model, icariin similarly retarded tumor growth
significantly, and suppressed tumor cells proliferation and expression
level of NF-κB (Fig. 6G-L). Overall, the above data suggested that
icariin could suppress TNBC growth by inhibiting NF-κB signaling
pathway, which is consistent with the in vitro data.