Cell Wall Membrane Fraction of Chlorella sorokinianaEnhances Host Antitumor Immunity and Inhibits Colon Carcinoma Growth inMice

摘要

A colon cancer growth inhibitor partially purified from the isolated cell wallmembrane fraction of Chlorella sorokiniana, here referred to asChlorella membrane factor (CMF), was evaluated for itsantitumor and immunomodulatory effects in cell culture and in a colon carcinomamouse model. The CMF treatment dose- and time-dependently inhibited coloncarcinoma cell growth in 2-dimensional cultures. Treatment with CMF alsosignificantly inhibited the growth of colon carcinoma spheroids in 3-dimensionalcell culture in coculture with T lymphocytes. In a mouse CT26 colon carcinomaperitoneal dissemination model, intraperitoneal injection of CMF (10 or 30 mgdry weight/kg body weight, every other day) dose-dependently and significantlyattenuated the growth of tumor nodules via induction of tumor cell apoptosis.Evaluation of immune cell populations in ascites showed that CMF treatmenttended to increase T lymphocytes but lower granulocyte populations. The presentstudy suggests that the cell wall membrane fraction of Chlorellasorokiniana contains a bioactive material that inhibits coloncarcinoma growth via direct cell growth inhibition and stimulation of hostantitumor immunity. Hence, it is suggested that the Chlorellacell wall membrane extract or a bioactive substance in the extract is anattractive complementary medicine for cancer therapy.