Cancer preventive effect of Kumaizasa bamboo leaf extracts administered prior to carcinogenesis or cancer inoculation.

BACKGROUND

Kumaizasa bamboo found in Hokkaido is used for traditional medicine in Japan. The cancer preventive effect of vigorous (multistep) hot water extract of Kumaizasa was examined in relation to immunological conditioning and free radical scavenging activity.

MATERIALS AND METHODS

Cytokine induction in mice, free radical scavenging activity in vitro, and cancer preventive effect by oral administration of the vigorous extracts prior to tumor implantation or carcinogenesis by 7,12-dimethylbenz[a]anthracene (DMBA) were examined.

RESULTS

In tumor inoculated mouse models (S-180 sarcoma, Meth-A fibrosarcoma, B16-F10 melanoma), the vigorous extracts from Kumaizasa bamboo leaves suppressed tumor growth and prolonged survival significantly. In the chemical carcinogenesis model suppression of cancer incidence on day 100, tumor size and survival time were significantly improved with the vigorous extract, at/or above 0.03% in the diet, when given two weeks prior to the administration of the carcinogen.

CONCLUSION

The vigorous extracts of bamboo leaf show immunopotentiating and radical scavenging effects and administration prior to carcinogen exposure or tumor inoculation significantly suppresses tumor incidence and tumor growth and prolongs survival.