W Jia1, H Yan1, P Sun2, E Guns3
1Univ. of B.C., Surgery, Vancouver, B.C., Canada;
2PanaGin Pharmaceuticals, Vancouver, Canada;
3Prostate Research Centre, Vancouver, BC, Canada
International Journal of Cancer 2002 Volume 100, Issue S13

The background of the study: Careseng is a natural product containing 4 major ginseng sapogenins, including Rh2 and Protopanaxadiol. In previous studies, these compounds have shown various anti-cancer activity, including G1-phase arrest and induction of apoptosis.

The method used: We have tested the anti-cancer activity of Careseng as well as Rh2 and protopanaxadiol on multi-drug resistant breast cancer cells in cell cultures and animal models. Toxicity of Careseng on animals was also examined.

The results obtained: Our results showed that 48 hours treatment with Careseng caused cell death in both MCF7adr and MDA435/LCC6mdr cell lines with IC50s between 10-20 ug/ml. This cytotoxity was similar to that caused by Rh2 or protopanaxadiol alone. In addition, Rh2 has shown extraordinary synergy with taxol on MDA435/LCC6mdr and its parental non-drug resistant cell line MDA435/LCC6. The drug sensitization effect was more dramatic in drug resistant MDA435/LCC6 cells, where Rh2 reduced IC50 for taxol by 21000-fold at the concentration of 30ug/ml. It was apparent that the cytotoxicity of Careseng or its individual components was not dependent on the levels of estrogen receptors or p53 status. Acute toxicity test on animals showed a transient mild CNS inhibitory effect at the maximum dose (4000 mg/kg). No animal died. Chronic toxicity included a transient hypertrophy in the prostate and ovary at the highest dose (333 mg/kg for 8 weeks).

The conclusion: The above results showed that Careseng is a safe product with a strong potential as a complementary treatment for breast cancer patients.

Proc Am Soc Clin Oncol 22: page 888, 2003 (abstr 3571)
W. Jia, H. Yan, X. Bu, G. Liu;
University of British Columbia, Vancouver, BC, Canada

Background: For thousands of years ginseng (Panax Quinquefolium L.) preparations have been used for health remedies. The main ingredients in ginseng with therapeutic activity are Ginseng saponins (ginsenosides) but only few of these ginsenosides, notably Rh1/2 and Rg3, demonstrate cytotoxicity on cancer cells. Since most ginseng preparations contain only trace amounts of these anticancer compounds, effects of direct inhibition on cancer cell growth are limited with regular ginseng extracts.

Method: In the present study, a specially formulated ginseng product, Careseng containing over 80% of Rh2 and Rh2-like ginsenosides, was tested on cultured breast, prostate, lung, pancreatic and brain cancer cell lines and in an intracranial glioma rat model to study anticancer properties.

Results: Our results showed that in vitro, Careseng induced G1 arrest and differentiation at low concentrations (<20ig/ml) and caused apoptosis at higher concentrations (>40ig/ml) in all cancer cell lines tested. Careseng induced apoptosis was independent of P53, but requisite of caspase activation, as DEVD, a caspase blocker completely abolished this activity. In all cancer cell lines, Careseng?apoptotic index was dose dependent. Furthermore, when Careseng was combined with Taxol, Mitoxantrone and Cisplatin in vitro, a synergistic effect on cytotoxicity was demonstrated. In a 9L glioma rat model, oral administration of Careseng?(25-50mg/kg) reduced mortality by 60%, and elongated the average life span of tumor bearing animals compared to controls (32+3 days versus 18+1 days; p<0.001). Acute (4000mg/kg) and chronic (300mg/kg/day for 8 weeks) toxicity tests in mice showed no significant adverse effects.

Conclusion: The above results demonstrate that Careseng has provocative and novel anticancer properties that render it an important new anticancer drug candidate which should be tested further in clinical studies.

W. Jia, H. Yan, X. Bu, G. Liu, Y. Zhao;
University of British Columbia, Vancouver, BC, Canada;
PanaGin Pharmaceuticals, Vancouver, BC, Canada
Journal of Clinical Oncology, 2004 ASCO Annual Meeting Proceedings. Vol 22, No 14S: 9663

Background: Aglycone Protopanaxadiol (aPPD) is an aglycone derivative of ginseng saponins. Our previous work showed that a natural ginseng product CARESENGTM containing mainly aPPD induced cell apoptosis through various signal pathways including caspases. CARESENGTM also enhances the sensitivity of multidrug resistant cancer cells to various chemotherapy drugs. P-glycoprotein (P-gp, MDR1) is one of the major causes of multidrug resistance of many tumor cells. Blocking the function of P-gp may enhance efficacy of chemotherapy. In the present study, we investigated the possible mechanism of chemosensitizing effect of purified aPPD compound as well as CARESENGTM.

Methods: Breast cancer cell MCF-7adr and leukemia cell line P388adr, both overexpressing P-gp, were used to test the interaction between the compound and P-gp. Calcein-AM, a P-gp substrate, efflux assay was used to measure function of P-gp. Membrane preparation was also used to measure the ATPase activity of P-gp in the presence of aPPD or verapamil.

Results: Our results demonstrated that 70uM aPPD could significantly block P-gp function on both MCF-7adr and P388adr cells showing increased intracellular concentrations of calcein-AM. Furthermore, the maximum effects of aPPD and verapamil on P-gp inhibition was additive when treated together on P388adr cells. On the other hand, aPPD had no effect on ATPase activity of P-gp while verapamil increased it by more than 2-fold. 20uM of aPPD completely reversed P-gp induced drug resistant to Taxol or Doxorubicin on MCF-7adr cells. CARESENGTM gave rise to similar results in all the above experiments.

Conclusions: These results suggest that aPPD is an effective P-gp blocker with a mechanism different from that of verapamil. Given extremely low toxicity of the compound, aPPD is a potential candidate of chemosensitizer for treatment of multidrug resistant tumors.

Jia WW, Bu X, Philips D, Yan H, Liu G, Chen X, Bush JA, Li G.
Department of Surgery, University of British Columbia, Vancouver, Canada
Can J Physiol Pharmacol. 2004 Jul;82(7):431-7.

Rh2 is a ginsenoside extracted from ginseng that has drawn attention in a few laboratories in Asian countries because of its potential tumor-inhibitory effect.

In the present study, we tested Rh2 on many tumor-cell lines for its effects on cell proliferation, induction of apoptosis, and potential interaction with conventional chemotherapy agents.

Our results showed that Rh2 inhibited cell growth by G1 arrest at low concentrations and induced apoptosis at high concentrations in a variety of tumor-cell lines, possibly through activation of caspases. The growth arrest and apoptosis may be mediated by 2 separate mechanisms. Apoptosis is not dependent on expression of the wild-type p53 nor the caspase 3. In addition, the apoptosis induced by Rh2 was mediated through glucocorticoid receptors. Most interestingly, Rh2 can act either additively or synergistically with chemotherapy drugs on cancer cells. Particularly, it hypersensitized multidrug-resistant breast cancer cells to paclitaxel.

These results suggest that Rh2 possesses strong tumor-inhibiting properties, and potentially can be used in treatments for multidrug-resistant cancers, especially when it is used in combination with conventional chemotherapy agents.

X. Ouyang, Z. Yu, Z. Chen, F. Xie, W. Fang, Y. Peng, X. Chen, W. Chen, W. Wang, P. Qi, W. Jia
Journal of Clinical Oncology, 2005 ASCO Annual Meeting Proceedings. Vol 23, No. 16S, Part I of II: 3188

Background: PBD2131 (Pandimex) is a preparation of aglycone saponins obtained from ginseng. The main active molecules in PBD2131 are 20(S)protopanaxadiol(aPPD) and 20(S)protopanaxatriol(aPPT). Both have shown strong anti-cancer effects in various cancer models(G.Liu, et al. AACR 2004). Both compounds induce apoptosis through caspase-dependent and -independent pathways and inhibit p-glycoprotein. This study was to investigate the safety and efficacy of PBD2131 used with or without paclitaxel.

Methods: Twenty-three patients with advenced solid tumors (lung, gastric, breast, and pancreatic), among whom 9 had distant metastasis, and all failed in previous chemotherapies, were randomized into 3 arms: 1) PBD2131 1000 mg i.v. plus paclitaxel 90 mg/m2 i.v. every 3 weeks for 2 cycles; 2) PBD2131 1000 mg i.v. twice weekly plus paclitaxel 60 mg/m2 i.v. once a week for 2 weeks. Repeat the cycle after a 2-week rest; and 3)PBD2131 1000 mg i.v. alone twice weekly for 4 weeks. Repeat the cycle after a 2-week rest. All patients were pre-treated with dexamethasone, diphenhydramine and cimetidine to reduce hypersensitivity. Blood, liver and kidney functions were tested weekly. Toxicity and adverse events were assessed according NCI Common Toxicity Criteria Manual. Tumor responses as shown in image were assessed according to RECIST.

Results: As summarized in the TableI, there were 6 Grade I and 1 Grade II adverse events (AE) observed. Two of the AEs (Grade I) were in the PBD2131 alone arm and 5 were in the PBD2131-paclitaxel combination arms. There were 4 PRs and 13 SDs observed (1 patient was lost to follow-up).

Conclusions: PBD2131 used alone or in combination with paclitaxel appears to be clinically active in advanced and metastatic solid tumors. The regimens are well-tolerated at the doses studied.

Xie X, Eberding A, Madera C, Fazli L, Jia W, Goldenberg L, Gleave M, Guns ES.
Prostate Centre at Vancouver General Hospital, University of British Columbia, Vancouver, British Columbia, Canada
J Urol. 2006 May;175(5):1926-31.

PURPOSE: We explored the efficacy of the ginsenoside Rh2 and examined its impact on the effective dose of paclitaxel and mitoxantrone in the LNCaP prostate tumor model.

MATERIALS AND METHODS: Cultured LNCaP cell viability was assessed following treatment (48 hours) with Rh2 (0 to 40 microM) alone or in combination with paclitaxel and mitoxantrone. Synergism or antagonism observed when combining treatment was calculated using CalcuSyn software (Biosoft). In addition, the inhibition of LNCaP human xenograft tumor growth was examined in vivo when Rh2 treatment was combined with chemotherapy. Harvested tumors were immunohistochemical stained with p27kip and Ki67.

RESULTS: Rh2 and paclitaxel act synergistically in cultured LNCaP cells to lower ED50 and ED75 values. Rh2 and mitoxantrone are also synergistic. However, when combined as ED95, an antagonistic effect was observed in this cell line. Treatment of LNCaP tumors by Rh2 plus paclitaxel produced a significant decrease in tumor growth and serum prostate specific antigen. Immunohistochemical analysis revealed an apparent but nonsignificant effect on proliferation markers in LNCaP tumors. When Rh2 and mitoxantrone were combined in vivo, there was no significant benefit observed.

CONCLUSIONS: These results indicate that the combination of Rh2 and paclitaxel has an effect on growth inhibition that is greater and synergistic, as demonstrated in a cultured LNCaP cell line. Conversely combining Rh2 with mitoxantrone appears to elicit no benefit. Therefore, combination therapy using chemotherapy and Rh2 requires further investigation.

Yan Yu, MD, MSc1, Qun Zhou, MSc1, Yan Hang, MD1, Xuexian Bu, MSc1, William Jia, PhD1 2
1Department of Surgery, University of British Columbia, Vancouver, British Columbia, Canada
2Brain Research Center, University of British Columbia, Vancouver, British Columbia, Canada
Cancer 2007 Volume 109 Issue 11, Pages 2374 – 2382

BACKGROUND. 20S-protopanaxadiol (aPPD) is a major gastrointestinal metabolic product of ginsenosides. The latter share structural similarity with steroids and are the main pharmacologically active component in ginseng.

METHODS. The authors investigated the interaction between aPPD and estrogen receptors (ER) in human breast adenocarcinoma MCF-7 cells through receptor binding assay, ER-induced gene expression, and cell proliferation both in vitro and in vivo.

RESULTS. aPPD, but not its close analog ginsenosides, competed with the [3H]-17-β estradiol (E2) for ER with IC50 at 26.3 uM. aPPD alone weakly induced luciferase reporter-gene expression controlled by an estrogen-regulated element, which was completely blocked by tamoxifen. aPPD alone, or in synergy with tamoxifen, blocked E2-induced transcriptional activation. aPPD also inhibited colony formation of endometrial cancer cells. aPPD potently inhibited estrogen-stimulated MCF-7 cell proliferation and synergistically enhanced the cytotoxicity of tamoxifen on both ER+ MCF-7 and ER- MDA-MB231 cells. Furthermore, aPPD, but not tamoxifen, inhibited Akt phosphorylation. Growth of MCF-7 xenograft tumor supplemented with E2 was completely inhibited in animals treated with aPPD, tamoxifen, or aPPD plus tamoxifen.

CONCLUSIONS. These results suggested that aPPD inhibits estrogen-stimulated gene expression and cell proliferation in ER-positive breast cancer cells. In addition, aPPD synergistically enhances cytotoxicity of tamoxifen in an ER-independent fashion, probably by down-regulating Akt activity.

Liu GY, Bu X, Yan H, Jia WW.
Department of Surgery and Brain Research Center, University of British Columbia
F233-2211 Wesbrook Mall, Vancouver, BC, V6T 2B5, Canada.
J Nat Prod. 2007 Feb; 70(2):259-64.

20S-Protopanaxadiol (1) is an aglycon metabolic derivative of the protopanaxadiol-type ginseng saponins.

In the present study, 1 was used to induce cytotoxicity for two human glioma cell lines, SF188 and U87MG. For the SF188 cells, 1 activated caspases-3, -8, -7, and -9 within 3 h and induced rapid apoptosis, which could be partially inhibited by a general caspase blocker and completely abolished when the caspase blocker was used in combination with an antioxidant. Compound 1 also induced cell death in U87MG cells but did not activate any caspases in these cells. Monodansylcadaverine staining showed that 1 induced dramatic autophagy in both cell lines. Elevated levels of superoxide anion in both cells and reduced levels of phosphorylated Akt in U87MG cells were also demonstrated.

These results showed that 20S-protopanaxadiol (1) induces different forms of programmed cell death, including both typical apoptosis and autophagy through both caspase-dependent and -independent mechanisms.