The researchers checked the cytotoxicity against an array of cancer cells in isolated 20(S)-25-methoxyl-dammarane-3 beta, 12 beta, 20-triol (25-OCH3-PPD), a natural product obtained from Panax notoginseng. The researches reported the efficacy of the above said compound in the vitro and in vivo on human prostate cancer cells, LNCaP (androgen-dependent) and PC3 (androgen-independent), based on the assessment on three structurally linked ginsenosides - ginsenoside Rh2, ginsenoside Rg3, and 20(S)-protopanaxadiol.

25-OCH3-PPD was the most powerful compound among the four test compounds used. The use of this compound led to G1 cell cycle arrest by decreasing survival, inhibiting proliferation and inducing apoptosis. During the test, the proteins associated with cell proliferation such as MDM2, E2F1, cyclin D1, and cdks 2 and 4 were decreased and the pro-apoptotic proteins such as cleaved PARP, cleaved caspase-3, -8, and -9 were activated.

25-OCH3-PPD helps to reduce the effect of androgen receptor and prostate-specific antigen in LNCaP cells and inhibits the growth of prostate cancer xenograft tumors. Co-administration of 25-OCH3-PPD with conventional chemotherapeutic agents or with radiation led to powerful anti-tumor effects. The development of tumor was stopped after the administration of 25-OCH3-PPD and either taxotere or gemcitabine. According to W. Wang and colleagues of University of Alabama, 25-OCH3-PPD is low toxic in non-cancer cells and there is no observable toxicity in animals.

The researcher’s conclusion: Based on the pre-clinical data, 25-OCH3-PPD is a powerful therapeutic agent against both androgen-dependent and androgen-independent prostate cancer.