A Pilot Study on Anticancer Activities of Chinese Leek

Abstract

Objectives:

To investigate the anticancer activities of Chinese leek (Allium tuberosum Rottler; [CL]).

Design:

Fresh CL was extracted and reconstituted in phosphate-buffered saline. The in vitro antiproliferation activities of the extract were tested with two murine cancer cell lines and four human cancer cell lines. The in vivo anticancer effects were tested in C57BL mice with lung metastases of B16-F10 melanoma. The mice were inoculated with B16-F10 melanoma cells by intravenous (IV) injection on day 1. CL extract was given on days 6–8 by either IV injection or oral gavage. The lung metastases were examined on day 16.

Results:

The extract inhibited the in vitro growth of all six cancer cell lines studied. The dose-response curves were sigmoidal with IC₅₀ (50% inhibition concentrations) in the range of 2.5–13.0 mg of raw material per milliliter for the six cancer cell lines. At the CL concentration of 8–100 mg of raw material per milliliter, all the cells underwent apoptosis, and no live cells were left after being exposed to CL for 4–6 hours. Typical apoptosis-specific cell morpholog changes were observed under a microscope. The induction of cancer cell apoptosis by CL extract was further verified by the DNA ladder assay. Treatment with a daily oral dose of the extract (equivalent to 2.5 or 12.5 mg of raw material per gram of body weight) reduced the B16-F10 melanoma lung metastatic colonies in mice by 40% (p < 0.03). IV injection of the extract (equivalent to 1.25 or 6.25 mg of raw material per gram of body weight) did not show any effect.

Conclusions:

CL extract inhibited cancer cell growth and induced apoptosis in vitro. Oral administration of CL extract significantly reduced lung metastases in the present animal model.