In vitro studies of baicalin alone or in combination with Salvia miltiorrhiza extract as a potential anti-cancer agent.

Traditional Chinese herbal medicines (TCM) that for centuries have been used in disease prevention and treatment are finding use as alternatives to Western cancer therapies. From a panel of TCM, we chose four compounds representing two functional classes of botanicals, the purified plant flavins scutellarin (a circulatory stimulant) and baicalin (antipyretic), and two extracts purified from Salvia miltiorrhiza (SM-470, circulatory stimulant) and Camellia sinensis (Cam-300, antipyretic), and examined their anti-proliferation effects on the human breast cancer cell lines MCF-7 and T-47D. All four compounds inhibited MCF-7 and T-47D cell proliferation, baicalin being the most potent inhibitor. Moreover, the combination of compounds from different classes offers enhanced potential therapeutic benefits; the combination of SM-470 with scutellarin, Cam-300 or baicalin, augmented the inhibition of cell proliferation. A synergistic inhibitory effect on MCF-7 cell proliferation was also observed when SM-470 and baicalin were applied together. In contrast, inhibition of T-47D cell proliferation using the same combination was dependent on baicalin only. The anti-proliferative effects of these compounds can be extended to other cancer types; the human head and neck cancer epithelial cell lines CAL-27 and FaDu were also sensitive to the four drugs. Overall, SM-470, Cam-300, scutellarin and baicalin inhibited the proliferation of human breast cancer cells and CAL-27 and FaDu cells with different potency. Baicalin and SM-470 in combination produced additive effects, suggesting these compounds may function by different mechanisms. T-47D, MCF-7, and FaDu cells may be useful in exploring the cellular and molecular mechanisms of action of baicalin and SM-470.