Anti-metastatic and immunomodulating properties of the water extract from Celosia argentea seeds.

We have investigated the anti-metastatic effect of Celosia argentea seed extracts (CAE), which have traditionally been used as a therapeutic drug for eye and hepatic diseases in China and Japan. Intraperitoneal (i.p.) administration of CAE for 7 d before tumor inoculation significantly inhibited liver metastasis caused by intraportal injection of colon 26-L5 carcinoma cells in a dose-dependent manner. CAE also showed concentration dependent mitogenic activity on BALB/c whole splenocytes, whereas incubation of the non-adherent fraction of splenocytes with CAE did not induce this activity. CAE has the ability to induce interleukin (IL)-12 production from macrophages in vitro. Following i.p. administration of CAE the maximal levels of IL-12 and interferon (IFN)-gamma production in serum were achieved at 2-3 and 6 h, respectively. Experiments using macrophage- or NK cell-deficient mice revealed that CAE-induced IL-12 in serum was not mediated by macrophages and that IFN-gamma production was mainly dependent on natural killer (NK) cells. Since CAE was inactive when the contributions of macrophages were removed in our system, its inhibitory mechanism is likely to be mainly associated with the activation of macrophages to an anti-metastatic state rather than NK cells. CAE administration resulted in increased production of IL-2, IFN-gamma and decreased production of a Th2 cytokine (IL-4) from splenocytes stimulated by PMA and A23187. Thus, the anti-metastatic effect by CAE is based on its immunomodulating properties including induction of cytokines such as IL-12, IL-2 and IFN-gamma leading to a Th1 dominant immune state and activating macrophages to the tumoricidal state. This may provide a basis for the inhibition of cancer metastasis.

Oral administration of a Kampo (Japanese herbal) medicine Juzen-taiho-to inhibits liver metastasis of colon 26-L5 carcinoma cells.

We have investigated the inhibitory effect of oral administration of Juzen-taiho-to, a Kampo Japanese herbal medicine, on liver metastasis by the inoculation of a liver-metastatic variant (L5) of murine colon 26 carcinoma cells into the portal vein. Oral administration of Juzen-taiho-to for 7 days before tumor inoculation resulted in dose-dependent inhibition of liver tumor colonies and significant enhancement of survival rate as compared with the untreated control, without side effects. We also found that liver metastasis of L5 cells was enhanced in BALB/c mice pretreated with anti-asialo GM1 serum or 2-chloroadenosine, and in BALB/c nu/nu mice, compared to normal mice. This indicates that NK cells, macrophages, and T-cells play important roles in the prevention of metastasis of tumor cells. Juzen-taiho-to significantly inhibited the experimental liver metastasis of colon 26-L5 cells in mice pretreated with anti-asialo GM1 serum and untreated normal mice, whereas it did not inhibit metastasis in 2-chloroadenosine-pretreated mice or T-cell-deficient nude mice. Oral administration of Juzen-taiho-to activated peritoneal exudate macrophages (PEM) to become cytostatic against the tumor cells. These results show that oral administration of Juzen-taiho-to inhibited liver metastasis of colon 26-L5 cells, possibly through a mechanism mediated by the activation of macrophages and/or T-cells in the host immune system. Thus, Juzen-taiho-to may be efficacious for the prevention of cancer metastasis.