OBJECTIVES

To investigate the anticancer activities of a Chinese herb, Oldenlandia diffusa (Bai Hua She She Cao).

METHODS

The water extract of the raw herb Oldenlandia diffusa was used in this study. The in vitro anti-proliferative activities of the extract were tested against eight cancer cell lines and one normal cell line. Microscopic examination and DNA ladder analysis were carried out to determine the pro-apoptotic effect of the extract. In vivo studies were carried out to examine the anticancer activities of the extract using C57BL/6j mice bearing B16-F10 lung metastasis. Oldenlandia diffusa extract was given at the dose level of 5 g raw material/kg on Days 3-12 by oral gavage and the extent of lung metastases were examined on Day 14.

RESULTS

The extract exhibited a strong antiproliferative activity against all cancer cell lines tested. The concentrations of growth inhibition at 50% (IC(50)) ranged from 7 to 25 mg raw material/ml after 48-hour treatment. The extract had a very limited cytotoxicity (10% inhibition) on the normal pancreatic cells even at the concentration of 50 mg/mL. Apoptosis in B16-F10 cells after treatment with the extract was observed by microscopic examination and DNA ladder assays. Oral administration of the herbal extract effectively reduced B16-F10 cell growth in the lungs of C57Bl/j mice with a 70% reduction in lung metastases (p < 0.001).

CONCLUSIONS

Oldenlandia diffusa extract effectively inhibited the growth of all the eight cancer cell lines and induced significant increase of apoptosis. The extract exhibited minimum toxic effect on normal pancreatic cells. Furthermore, there was a significant inhibition of lung metastases in the animal model with no noticeable adverse effects. The herb extract could be a potential anticancer agent.