Protective Effects of Punicalagin on Caco-2 Intestine Cell Line under Oxidative Stress Caused by Tert-butyl hydroperoxide
Pages 249-256
Ulfat Omar, Akram Aloqbi, Marwa Yousr and Nazlin Howell
DOI: http://dx.doi.org/10.6000/1927-5951.2015.05.04.5
Published: 08 January 2016

Abstract: Hydrolysable tannin polyphenols from pomegranate (punicalagin) have been reported to show a wide range of health properties correlated to their high antioxidant and free radical scavenging activities. The objective of the current study was to investigate the protective effect of punicalagin on cell viability and redox status of cultured Caco-2 cells exposed to oxidative stress induced by tert-butyl hydroperoxide. The production of malondialdehyde, and total glutathione levels, as well as the generation of reactive oxygen species were used as markers of cellular oxidative status. Pretreatment of Caco-2 cells with 5 and 10 µM punicalagin for 24 hours significantly protected cell viability after exposure to tert-butyl hydroperoxide IC₅₀ = 3 mM for 2 hours. The examined doses prevented the decrease of total glutathione and the increase of malondialdehyde induced by tert-butyl hydroperoxide in Caco-2 cells. Reactive oxygen species generation provoked by tert-butyl hydroperoxide was significantly reduced at the same concnetrations. Finally, cell morphology with treatments before and after induction by tert-butyl hydroperoxide showed irreversible effect of the oxidizing agent. The results of the biomarkers analyzed showed that treatment of Caco-2 cells with the natural dietary antioxidant punicalagin protected the cells against oxidative stress.

Keywords: Polyphenols, Malondialdehyde, Glutathione, Reactive oxygen species, morphology.

Can Plants’ Ability for DNA Repair and Stress Defense be Used against Patients’ Circulating Tumor Cells?
Pages 157-178
C.D. Volko and U.D. Rohr
DOI: http://dx.doi.org/10.6000/1927-5951.2015.05.03.1
Published: 25 August 2015

Abstract: Introduction: It was suggested that specific plants may reduce cancer's resistance to chemotherapy. Resistance inhibits apoptosis, as well as other fundamental anti-cancer protective mechanisms. Soy bean has been found to reduce cellular stress and repair DNA damage caused by drought or parasites, and can transfer this defense mechanism to other plant species as well. The aim of this study is therefore to conduct a systematic comparison of the effect of soy bean formulation (FSWW08) on gene expression in in vitro human breast cancer cell line, and in in vivo in blood circulating tumor cells (CTC), after oral consumption of FSWW08 by patients suffering from breast-, ovarian-, and prostate cancer.

Method: In vitro gene expressions studies were conducted with the human breast cancer cell line BT-474 that was exposed to doxorubicin or FSWW08, either alone or in combination. Ovarian-, prostate-, and breast cancer patients received FSWW08 for 30 days. CTC were extracted from their blood according to an established protocol. Gene expression evaluations were conducted before and after treatment.

Results: In vitro,the multi-drug resistance (MDR) protein was reduced by FSWW08, but was increased by doxorubicin. The combination of FSWW08 and doxorubicin, however, showed a protective effect against the increase of MDR in physiologic concentrations, increased, however, also in high experimental concentrations of both agents. The expression of several cancer-related protective genes, such as tumor suppressor factors p21, p38 and p53, was improved by FSWW08 in vitro and in vivo, which helped cell differentiation and new tissue formation. Additionally, the BAX/Bcl₂ ratio was improved, in vitro, as well as gene expression of estrogen receptor beta, NF-κB, MAP kinase, c-JUN, and matrix metalloproteinase 9, together with an increase of VEGF expression in vivo in CTC.

Conclusion: It was demonstrated that FSWW08 improved the gene functions related to DNA repair and stress in human blood CTC and resistance marker, in vitro, when applied in combination with doxorubicin. As such, larger in vitro and in vivo clinical studies that investigate single botanical compounds from other plants, are warranted.

Keywords: Tp53, Tp21, Bax/Bcl2, MAP kinase, VEGF, CTC, circulating tumor cell, fermented soy, MDR protein, estrogen receptor beta, NF-κB, RT-PCR technique, human breast cancer cell line BT-474, ovarian cancer, breast cancer, prostate cancer.