Milestone in Cancer Stem Cell Research

Pao Pereira Fights Cancer Stem Cells!

New research just published in Integrative Cancer Therapies shows that the Pao pereira plant extract inhibits pancreatic cancer stem cells. This dramatic result means that the extract will be useful for preventing cancer recurrence.

Everyone knows that cancer treatments are not cancer cures. Chemotherapy treatments kill cancer cells and shrink tumors, but the cancer often comes back. Cancer stem cells (CSCs) are the culprit because they are resistant to anti-cancer drugs, they can metastasize and form new tumors. CSCs make up a small fraction of the cells in a tumor that survive after the majority of primary cancer cells are killed by anti-cancer drugs. The CSCs persist, spread and restart tumor growth.

CSCs are also referred to as cancer stem-like cells because they share the capacity for self-proliferation with normal stem cells that are involved in the renewal and repair of tissues, but unlike normal stem cells, CSCs are cancerous and drug resistant.

In vitro experiments show Pao pereira reducing the number of pancreatic CSCs (see figure below).

As the amount of Pao pereira is increased, the number of pancreatic cancer stem cells (spheroids) decrease dramatically. In additional cell-based studies, the Pao pereira extract also specifically reduced the pancreatic cancer stem cell population.

In vivo experiments showed that Pao pereira inhibited the capacity of pancreatic CSCs to form tumors – the defining characteristic of CSCs – and significantly reduce the volume of tumors that did form (see figure below).

At day 6 (Figure A), tumor formation rate in the control group reached 80%, while in Pao-treated group it was only 10%. At day 20, when the treatment stopped, all mice in control group were bearing tumors on both flanks (100% tumor formation), while the Pao-treated group only had 30% tumor formation. Growth of the formed tumors was also inhibited by Pao pereira treatment compared with the control group (Figure B). A long-term inhibitory effect in tumor growth was observed after treatment had stopped. Pao pereira works by lowering the signals that trigger the pancreatic cancer stem-like cell properties that lead to cancer recurrence.

The researchers at Kansas University Medical Center concluded that Pao pereira holds great promise as a novel treatment for targeting pancreatic CSCs, an essential component of treatments that will lead to real cancer cures.

Extract of the Medicinal Plant Pao Pereira Inhibits Pancreatic Cancer Stem-Like Cell In Vitro and In Vivo
Dong, P. Chen and Q Chen. Integrative Cancer Therapies. July 2018. doi: 10.1177/1534735418786027

Publication on Rauwolfia Vomitoria Extract against Pancreatic Cancer

March 2014 – 'Antitumor Activities of Rauwolfia vomitoria Extract and Potentiation of Gemcitabine Effects Against Pancreatic Cancer'

by Jun Yu, PhD and Qi Chen, PhD
Integrative Cancer Therapy. 2014 Apr 24;13(3):217-225.

Kansas universityThe fourth publication from the scientific collaboration between the Beljanski Foundation and Kansas University Medical Center has been released. It shows, in vitro and in vivo, the effectiveness of Rauwolfia vomitoria (the extract prepared according to Dr. Mirko Beljanski's proprietary process) on pancreatic cancer cells. This publication also confirms – if confirmation were needed – the non-toxicity of Rauwolfia ('Rau'), on healthy cells, its selective effect against cancer cells, and its excellent synergistic action with Gemcitabine chemotherapy. This study, conducted with extracts provided by Natural Source International, Ltd. is now available on The Beljanski Foundation website.

For the purpose of this study, pancreatic cancer cells were inoculated into four groups of mice (control group treated with saline solution, mice treated with Gemcitabine alone, mice treated with Rauwolfia alone, and mice with combination treatment of Gemcitabine and Rauwolfia). As the tumors did not respond to Gemcitabine, Rauwolfia at either 20 mg/kg or 50 mg/kg provided observable inhibition in tumor growth. The combination of Gemcitabine + Rauwolfia at both doses also inhibited tumor progression. Notably, there were 2 mice in the Gemcitabine + Rauwolfia 50 mg/kg group that had complete tumor regression, an effect that was not observed in any other treatment group.

Necropsy confirmed the imaging results at the end of the treatment. Gemcitabine at the dose used did not provide any reduction in tumor weight, when Rauwolfia alone decreased tumor weight by 53% at the daily dose of 20 mg/kg, and 46% at the daily dose of 50 mg/kg, compared with saline-treated control. By combining Rauwolfia with Gemcitabine, the decrease in tumor weight was 56% at both Rauwolfia doses. The improvement in tumor inhibition provided by the combination was significant compared with that of Gemcitabine alone.

On assessing tumor metastasis, 12% of mice in the control group (saline-treated) and in the Rauwolfia 20 mg/kg group did not form metastasis, whereas all mice in Gemcitabine group formed metastasis. The percentage of metastasis free mice increased to 40% with both Rau 50 mg/kg treatment and Gemcitabine + Rauwolfia treatment, suggesting that Rauwolfia provided benefit in reducing metastatic potential while Gemcitabine did not.

None of the mice demonstrated observable toxicity associated with the treatments. At the end of the experiments, major organs (kidney, liver, and spleen) were subjected to hematoxylin and eosin staining and histopathological analysis. No tissue damage was detected in the treatment groups, and there were no significant differences between the control group and the treated group. This data demonstrated that Rauwolfia at the dose used, either alone or combined with Gemcitabine, was effective and, at the same time, low in toxicity.
This would open an avenue to reduce toxicity associated with chemotherapy.


Pancreatic cancer is one of the most lethal malignancies with very limited treatment option. In the effort of enhancing the effect of the conventional chemotherapeutic drug gemcitabine against pancreatic cancer, we investigated in vitro and in vivo the anticancer effect of a β-carboline-enriched extract from the plant Rauwolfia vomitoria (Rau), either alone or in combination with gemcitabine, in preclinical pancreatic cancer models. Rau induced apoptosis in pancreatic cancer cells in a concentration-dependent manner, and completely inhibited colony formation of PANC-1 cells in soft agar.
The combination of Rau and gemcitabine had synergistic effect in inhibiting cell growth with dose reduction effect for gemcitabine. In an orthotopic pancreatic cancer mouse model, PANC-1 tumor growth was significantly suppressed by Rau treatment. Metastasis was inhibited by Rau. Adding Rau to gemcitabine treatment reduced tumor burden and metastatic potential in the gemcitabine non-responsive tumor. These data suggest that Rau possesses anti–pancreatic cancer activity and could improve effect of gemcitabine.

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Publication on Pao pereira Extract against Pancreatic Cancer

March 2013 – 'Inhibition of Pancreatic Cancer and Potentiation of Gemcitabine Effects by the Extract of Pao Pereira'

Oncology Reports' Journal (doi: 10.3892/or.2013.2461)

Kansas universityThe scientific team at the University of Kansas Medical Center has just published a new article entitled, 'Inhibition of Pancreatic Cancer and Potentiation of Gemcitabine Effects by the Extract of Pao Pereira' in the 'Oncology Reports' Journal (doi: 10.3892/or.2013.2461).

This scientific paper describes the results of in vitro and in vivo studies demonstrating the anti-cancer effect of the Pao pereira extract, used alone and in combination with gemcitabine (chemotherapy used in most cancer treatments), in multiple cancer cell lines including those of the pancreas resistant to anti-mitotic drugs.

Pre-clinical studies conducted with mice, both in vitro an in vivo, confirm that adding Pao Pereira to the treatment regiment reduced the concentration of Gemcitabine to produce an equitoxic effect on pancreatic cancer cells. The Pao's anti-cancer effect was seen in vivo and in vitro working alone and in conjunction with other chemotherapy treatments. Over the course of the study, the Pao pereira was seen to suppress tumor growth significantly, by up to 72%.

This confirms another study, published just a few years ago, out of Columbia University demonstrating that the two plant extracts, Pao Pereira and Rauwolfia Vomitoria, contain Beta-Carbolines with effective anti-cancer properties which inhibit cancer cell growth, even in those cells resistant to drugs used in chemotherapy. This study, specific to anti-prostate cancer activity, also substantiated that all healthy cells were not negatively affected, thus demonstrating the safety of the plant extracts prepared by the Beljanski method.

With such promising initial results, the research will continue on Pao Pereira to assess its effectiveness on other types of cancerous cells!


Kansas - Pao - PancreasLack of effective therapy is a major problem in the treatment of pancreatic cancer. In the present study, we investigated a natural product, the extract of Pao Pereira (Pao), for its anti-pancreatic cancer effect in vitro and in vivo, either alone or in combination with the first-line chemotherapeutic drug gemcitabine (Gem). Pao induced dose-dependent apoptosis to all five tested pancreatic cancer cell lines. The combination of Pao and Gem had a synergistic effect in the inhibition of cell growth, with combination indices (CIs)

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