Cucurbitacin B downregulates the expression of JAK2/STAT3 signalling cascades. (A) Western blot analysis indicates that cucurbitacin B induced marked downregulation of JAK2 and STAT3 expression, thereby inhibiting the signaling cascade and (B) quantified results indicate a significant reduction in expression of JAK2/STAT3 signaling cascades. *P<0.05 vs. control; #P<0.05 vs. 100 µM. Data are presented as mean ± standard deviation, n=3. JAK2, Janus kinase 2; STAT3, signal transducer and activator of transcription 3; L1, control; L2, 25 µM cucurbitacin B; L3, 50 µM cucurbitacin B; L4, 100 µM cucurbitacin B.