Elsevier

Phytomedicine

Volume 19, Issues 8–9, 15 June 2012, Pages 763-767
Phytomedicine

Anethole suppressed cell survival and induced apoptosis in human breast cancer cells independent of estrogen receptor status

https://doi.org/10.1016/j.phymed.2012.02.017Get rights and content

Abstract

Background

Many traditional Chinese medicines target the treatment of inflammation which is emerging to be a critical component to cancer development and progression. The key aromatic compound in star anise anethole has demonstrated both anti and pro-cancerous effects depending on the estrogen receptor statuses in individual cell lines. In this study, we investigated the effect of anethole on the physiological responses and specific apoptotic pathways in human breast cancer MCF-7 and MDA-MB-231 cells that are well-characterized to represent estrogen receptor (ER) positivity and its counterpart in breast cancer respectively. How anethole affects the activity and expression of apoptotic caspases, the function of transcriptional factor NF-kB and the relative influence ER exerts on these events are areas of significant research relevance and results may impact the pharmaceutical development of anethole and its use as dietary supplementation.

Methodology/principal findings

Initial analyses of physiological responses using MTT and colony formation assays had demonstrated a preferentially suppression of cell survival to cell proliferation in both ER+ and ER− cells when cells were exposed to anethole. Western blot analysis has demonstrated induction of caspase 9 and PARP1/2 cleavage in parallel with elevated expression of c-FLIP (s) and p53. The transcriptional activity of NF-kB, an upstream activator of p53 is suppressed in both cell lines when treated with anethole.

Conclusions

In conclusion, anethole in an ER independent manner suppresses cell survival and induces apoptotic events in MCF-7 and MDA-MB-231 at an optimal concentration of 1 × 10−3 M. In search of alternative compounds for therapeutic development, this study has demonstrated that anethole may be viable as an anti-cancer agent through the modulation of apoptosis, cell survival and proliferation in breast cancer cells.

Introduction

Asian women have a significantly lower risk of developing breast cancer, believed to be at least in part due to diet and lifestyle. Star anise is a spice that has been used in many traditional Chinese medicines to reduce inflammatory symptoms. Anethole, 1-methoxy-4-(1-propenyl) benzene, is the principle aromatic compound found in star anise. For the past decade, numerous studies have been conducted with anethole and its analogs to uncover the potential anti-cancer effects in natural spices. One of anethole's derivatives, anethole ditholethione (ADT), has been shown to have anti-inflammatory properties that are competent in increasing intracellular levels of glutathione (GSH) and gluthione-S-transferase (GST) (Stohs et al. 1986) and in a phase II trial significantly reduced the lung cancer progression in smokers (Lam et al. 2002). Two other derivatives eugenol and isoeugenol inhibit lipid peroxidation and reduce oxidative levels by scavenging hydroxyl radicals (Taira et al. 1992). Anethole trithione significantly inhibits mammary cancer multiplicity in DMBA-induced rat mammary cancer models (Lubet et al. 1997) and azoxymethane-induced colon carcinogenesis (Reddy et al. 1993). However, several studies have suggested that anethole might not be an effective anti-cancer agent due to its estrogenic properties (Tabanca et al. 2004) and the proliferation promoting properties of its metabolite 4-hydroxy-1-propenylbenzene (4OHPB) (Nakagawa et al. 2003). In order to resolve this discrepancy, we proposed to evaluate the effect of anethole on several physiological parameters of human breast cancer cells in vitro and at the same time continue to delineate the mechanisms through which anethole might mediate its anti-inflammatory effects in the context of estrogen receptor involvement.

Section snippets

Cell lines and reagent

MCF-7 and MDA-MB-231 breast cancer cells were obtained from the American Type Culture Collection and maintained in Improved Minimal Essential Medium (Life Technologies Inc., Gaithersburg, MD) supplemented with 10% Fetal Bovine Serum (FBS) (Sigma, St. Louis, MO) and 6 ng/ml bovine insulin (Sigma). Trans-anethole was purchased from Sigma–Aldrich at 99% purity (cat no. 117870) and dissolved in DMSO to obtain a stock solution of 1 M.

Survival assay

Cell survival was assessed by colony formation assay. Cells were

Repression of survival in both estrogen receptor (ER) positive and ER negative cell lines

Discordance in the literature that investigates the chemopreventive efficacy of anethole and its contradicting estrogenic activity Derivatives of anethole have demonstrated anethole might act as a growth promoting or growth inhibitory compound, we were interested in the effect To determine whether trans-anethole has any impact on the cell survival, we conducted clonogenic assays using MCF-7 and MDA-MB-231 in which cell were treated with increasing (1 × 10−6–1 × 10−3 M) concentrations of anethole for

Discussion

The investigation of the anti-cancer effects anethole may mediate commences with the physiological assays of cell survival and cell proliferation. Initial assessment has found both negative and positive results in which anethole has failed to induce repression of cell proliferation when MCF-7 and MDA-MB-231 cells were incubated with 10−6–10−3 M of trans-anethole dissolved in DMSO for 94 h at 37 °C (Fig. 2A and B). However, in a colony formation assay, the identical concentrations have reduced, in

Acknowledgments

We thank Dr. George Mitchell from the University Co-operative Society in University of Texas at Austin for granting this project an Undergraduate Research Fellowship.

References (7)

There are more references available in the full text version of this article.

Cited by (56)

  • SPME and solvent-based GC–MS metabolite profiling of Egyptian marketed Saussurea costus (Falc.) Lipsch. concerning its anticancer activity

    2022, Phytomedicine Plus
    Citation Excerpt :

    In the same context, anethole decreased prostate cancer metastasis (DU145) cell line through upregulation of phosphatase and tensin homolog that inhibited the Akt pathway (Rhee et al., 2014). Anethole also successfully induced apoptosis of the prostate (Elkady, 2018), breast (Chen and DeGraffenried, 2012), and oral cancer cell lines (Contant et al., 2021). COS is another bioactive constituent of S. costus-induced apoptosis through B-cell lymphoma 2 downregulation of human leukemia cells (Li et al., 2020), colon and breast cancer cell lines (El-Far et al., 2021a, 2021).

View all citing articles on Scopus
View full text