Rosmarinic Acid, a Component of Rosemary Tea, Induced the Cell Cycle Arrest and Apoptosis through Modulation of HDAC2 Expression in Prostate Cancer Cell Lines.

Yin-Gi Jang,Kyung-Chul Choi,Kyung-A Hwang

doi:10.3390/nu10111784

Abstract

Rosmarinic acid (RA), a main phenolic compound contained in rosemary which is used as tea, oil, medicine and so on, has been known to present anti-inflammatory, anti-oxidant and anti-cancer effects. Histone deacetylases (HDACs) are enzymes that play important roles in gene expression by removing the acetyl group from histone. The aberrant expression of HDAC in human tumors is related with the onset of human cancer. Especially, HDAC2, which belongs to HDAC class I composed of HDAC 1, 2, 3 and 8, has been reported to be highly expressed in prostate cancer (PCa) where it downregulates the expression of p53, resulting in an inhibition of apoptosis. The purpose of this study is to investigate the effect of RA in comparison with suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor used as an anti-cancer agent, on survival and apoptosis of PCa cell lines, PC-3 and DU145, and the expression of HDAC. RA decreased the cell proliferation in cell viability assay, and inhibited the colony formation and tumor spheroid formation. Additionally, RA induced early- and late-stage apoptosis of PC-3 and DU145 cells in Annexin V assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively. In western blot analysis, RA inhibited the expression of HDAC2, as SAHA did. Proliferating cell nuclear antigen (PCNA), cyclin D1 and cyclin E1 were downregulated by RA, whereas p21 was upregulated. In addition, RA modulated the protein expression of intrinsic mitochondrial apoptotic pathway-related genes, such as Bax, Bcl-2, caspase-3 and poly (ADP-ribose) polymerase 1 (PARP-1) (cleaved) via the upregulation of p53 derived from HDAC2 downregulation, leading to the increased apoptosis of PC-3 and DU145 cells. Taken together, treatment of RA to PCa cell lines inhibits the cell survival and induces cell apoptosis, and it can be used as a novel therapeutic agent toward PCa.

Highlights

Phenolic compounds found in tea are known to have anti-oxidant and anti-cancer effects [1].Rosmarinic acid (RA) is a main phenolic compound in Rosmarinus officinalis L. which is a common herb cultivated in many parts of the world and has been consumed as tea, oil, medicine and so on [2,3]
We examined the anti-Prostate cancer (PCa) potential of RA as a novel phytochemical that can be substituted for the existing chemotherapeutic drugs including Histone deacetylases (HDACs) inhibitors
To select the inhibition concentrations of suberoylanilide hydroxamic acid (SAHA) and RA on PCa cell viability, the cell viability assay was done in PC-3 and DU145 cells

Summary

Introduction

Phenolic compounds found in tea are known to have anti-oxidant and anti-cancer effects [1].Rosmarinic acid (RA) is a main phenolic compound in Rosmarinus officinalis L. (called rosemary) which is a common herb cultivated in many parts of the world and has been consumed as tea, oil, medicine and so on [2,3]. Phenolic compounds found in tea are known to have anti-oxidant and anti-cancer effects [1]. Rosmarinic acid (RA) is a main phenolic compound in Rosmarinus officinalis L. (called rosemary) which is a common herb cultivated in many parts of the world and has been consumed as tea, oil, medicine and so on [2,3]. Prostate cancer (PCa) is the most leading type of cancer occurring in men and the second most common cause of cancer-related death worldwide [12]. Though chemotherapies, such as docetaxel, Nutrients 2018, 10, 1784; doi:10.3390/nu10111784 www.mdpi.com/journal/nutrients. Using the chemotherapeutic drugs in the long term allows aggressive PCa cells to experience mutations in the gene of beta-tubulin and activation of drug efflux pumps, leading to increased survival and the drug resistance [14,15,16]

Objectives

Methods

Results

Discussion

Conclusion