Natural Compounds as New Cancer Treatments

Ursolic Acid Accelerates Paclitaxel-Induced Cell Death in Esophageal Cancer Cells by Suppressing Akt/FOXM1 Signaling Cascade

Ursolic acid (UA), a pentacyclic triterpenoid extracted from various plants, inhibits cell growth, metastasis, and tumorigenesis in various cancers. Chemotherapy resistance and the side effects of paclitaxel (PTX), a traditional chemotherapy reagent, have limited the curative effect of PTX in esophageal cancer. In this study, we investigate whether UA promotes the anti-tumor effect of PTX and explore the underlying mechanism of their combined effect in esophageal squamous cell carcinoma (ESCC). Combination treatment with UA and PTX inhibited cell proliferation and cell growth more effectively than either treatment alone by inducing more significant apoptosis, as indicated by increased sub-G1 phase distribution and protein levels of cleaved-PARP and cleaved caspase-9. Similar to the cell growth suppressive effect, the combination of UA and PTX significantly inhibited cell migration by targeting uPA, MMP-9, and E-cadherin in ESCC cells. In addition, combination treatment with UA and PTX significantly activated p-GSK-3β and suppressed the activation of Akt and FOXM1 in ESCC cells. Those effects were enhanced by the Akt inhibitor LY2940002 and inverted by the Akt agonist SC79. In an in vivo evaluation of a murine xenograft model of esophageal cancer, combination treatment with UA and PTX suppressed tumor growth significantly better than UA or PTX treatment alone. Thus, UA effectively potentiates the anti-tumor efficacy of PTX by targeting the Akt/FOXM1 cascade since combination treatment shows significantly more anti-tumor potential than PTX alone both in vitro and in vivo. Combination treatment with UA and PTX could be a new strategy for curing esophageal cancer patients.

Changes in the Mineral Composition of Rat Tissues Induced by Breast Cancer and Dietary Supplementation

BACKGROUND/AIM

The aim of the study was to determine the effect of various diets with zinc or zinc in combination with resveratrol or genistein on mineral contents of the serum, urine, liver, kidney and heart in rats with chemically-induced mammary carcinoma.

MATERIALS AND METHODS

The manuscript presents the tissues and body fluids content of iron, calcium, zinc, magnesium and copper in control rats or rats treated with 7,12-dimethyl-1,2-benz[a]anthracene to induce mammary carcinogenesis, under four dietary conditions: standard feed, Zn supplemented feed (6.9 mg Zn/ml), Zn and resveratrol (0.2 mg/kg body) supplemented feed, or Zn and genistein (0.2 mg/kg body) supplemented feed.

RESULTS

The content of calcium and copper highly varied depending on the tissue and the type of dietary supplement (no change for zinc and magnesium). Irrespective of the diet used, the chemical induction of mammary cancer caused a decrease in iron concentration in most samples analysed. Only supplementation of the rats' diet with zinc and genistein induced no changes in iron distribution in the serum, urine, liver, kidney and heart.

CONCLUSION

Further research using various levels of zinc and genistein in the diet should be conducted to determine how the development and progression of cancer is linked to iron content in cells and its ability to accumulate in tumour tissue.