Panax ginseng C.A. Meyer has been the most highly recognized medicinal herb in the Orient. The prolonged administration of red ginseng extract significantly inhibits the incidence of
hepatoma and also proliferation of pulmonary
tumors induced by
aflatoxin B(1) and
urethane. Statistically significant
anticarcinogenic effects were in aged or heat treated extracts of ginseng and red ginseng made by steaming in a 9 weeks medium-term anticarcinogenicity test using
benzo[a]pyrene. In case-control studies, odds ratios (OR) of the
cancer of lip, oral cavity and pharynx, larynx, lung, esophagus, stomach, liver, pancreas, ovary, and colorectum were significantly reduced. As to the type of ginseng, the
ORs for
cancer were reduced in user of fresh ginseng extract intakers, white ginseng extract, white ginseng
powder, and red ginseng. In a cohort study with 5 years follow-up conducted in a ginseng cultivation area, ginseng users had a decreased relative risk (RR) compared with non-users. The relative risks (RRs) of ginseng users were decreased in
gastric cancer and
lung cancer. These findings strongly suggest that Panax ginseng C.A. Meyer cultivated in Korea has non-organ specific
cancer preventive effects against various
cancers. To investigate the active components for
cancer prevention, several fractions of fresh and red ginseng and four semi-synthetic
ginsenoside Rh(1), Rh(2), Rg(3) and Rg(5), the major
saponin components in red ginseng, were prepared among the
ginsenosides. By using Yun's model, Rg(3) and Rg(5) showed statistically significant reduction of lung
tumor incidence and Rh(2) had a tendency to decrease the incidence. In conclusion, these results strongly suggested that Panax ginseng C.A. Meyer cultivated in Korea is a non-organ specific
cancer preventive against human
cancers and also indicated that the anticarcinogenicity or human
cancer preventive effect of Panax ginseng is due to
ginsenoside Rg(3), Rg(5) and Rh(2).