Antitumor effects of Bulbus Fritillariae cirrhosae on Lewis lung carcinoma cells in vitro and in vivo

•Bulbus Fritillariae cirrhosae showed antitumor activity against LLC cells in vitro.•Bulbus F. cirrhosae showed antitumor effects and low toxicity in vivo.•Alkaloids of Bulbus F. cirrhosae arrested the cell cycle at S-phase in LLC cells.•Alkaloids of Bulbus F. cirrhosae inhibited tumor angiogenesis in LLC-bearing mice.•The alkaloids induced apoptosis by significant improvement of caspase-3 expression.

Bulbus Fritillariae cirrhosae (BFC) is used in China both for food and folk medicine due to its powerful biological activities. Initially we assayed antitumor effects of different fractions from BFC using MTT assay. Data indicated that chloroform extracts (CE) and total alkaloids of BFC (TAF) showed higher inhibition of proliferation of LLC cells than other extracts. We further determined contents of total alkaloids and three main alkaloids monomers in CE and TAF, and measured inhibitory effects of three main alkaloids monomers on LLC cells, it suggested that alkaloids might be responsible for all or part of the antitumor activity. Besides, we analyzed the cell cycle and sub-G1 group of LLC cells treated with TAF and found that TAF promoted the cell cycle arrest and apoptosis. Moreover, we defined antitumor activity of TAF in vivo and investigated its preliminary antitumor mechanism by histological and immunohistochemical staining technique. These results showed that TAF exhibited significant antitumor activity and low toxicity in vivo. Meanwhile, TAF significantly inhibited tumor angiogenesis and induced apoptosis through activating caspase-3. Overall, the potent antitumor activity of BFC suggests that it may be developed for treatment of cancer in the future.

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