Anti-Bladder-Tumor Effect of Baicalein from Scutellaria baicalensis Georgi and Its Application In Vivo

Abstract EN

Some phytochemicals with the characteristics of cytotoxicity and/or antimetastasis have generated intense interest among the anticancer studies.

In this study, a natural flavonoid baicalein was evaluated in bladder cancer in vitro and in vivo.

Baicalein inhibits 5637 cell proliferation.

It arrests cells in G1 phase at 100 μM and in S phase below 75 μM.

The protein expression of cyclin B1 and cyclin D1 is reduced by baicalein.

Baicalein-induced p-ERK plays a minor role in cyclin B1 reduction.

Baicalein-inhibited p65NF-κB results in reduction of cell growth.

Baicalein-induced pGSK(ser9) has a little effect in increasing cyclin B1/D1 expression instead.

The translation inhibitor cycloheximide blocks baicalein-reduced cyclin B1, suggesting that the reduction is caused by protein synthesis inhibition.

On the other hand, neither cycloheximide nor proteasome inhibitor MG132 completely blocks baicalein-reduced cyclin D1, suggesting that baicalein reduces cyclin D1 through protein synthesis inhibition and proteasomal degradation activation.

In addition, baicalein also inhibits cell invasion by inhibiting MMP-2 and MMP-9 mRNA expression and activity.

In mouse orthotopic bladder tumor model, baicalein slightly reduces tumor size but with some hepatic toxicity.

In summary, these results demonstrate the anti-bladder-tumor properties of the natural compound baicalein which shows a slight anti-bladder-tumor effect in vivo.