Journal of Ethnopharmacology 137 (2011) 1003–1010 Contents lists available at ScienceDirect Journal of Ethnopharmacology journa l h o me page: www.elsevier.com/locate/jethpharm Proliferative effects of five traditional Nigerian medicinal plant extracts on human breast and bone cancer cell lines N. Engel a , C. Oppermann c , A. Falodun b,∗ , U. Kragl c a Department of Cell Biology, Biomedical Research Center, University of Rostock, Schillingallee 69, 18057 Rostock, Germany b Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Benin, Nigeria c Institute of Chemistry, University of Rostock, Albert-Einstein-Str. 3A, 18059 Rostock, Germany a r t i c l e i n f o Article history: Received 22 April 2011 Received in revised form 14 June 2011 Accepted 6 July 2011 Available online 18 July 2011 Keywords: Plant extracts Herbal medicine Anticancer Flow cytometry a b s t r a c t Ethnopharmacological relevance: The medicinal plants Hunteria umbellata (HUL), Cola lepidota (CCL), Persea americana leaf (PAL), Root bark of Persea americana (RPA) and Plukenetia conophora (PCL) are used in Nigerian traditional medicine for the treatment of cancer and cancer related diseases. Aim of the study: To scientifically evaluate the cell proliferative and apoptotic effects of the plants extracts using breast and osteocarcinoma cell lines, and also to identify the possible components via LC–MS to have a kind of chemical fingerprint. Materials and methods: The antiproliferative and apoptotic effects of methanolic extracts (10 g/ml) of the five medicinal plants were subjected to in vitro evaluation using four cancer cell lines (breast-MCF-7 and BT-20; Osteocarcinoma-MG-63 and Saos-2) measured by flow cytometry. Non-tumorigenic controls MCF-12A and primary isolated osteoblasts (POB) were chosen to eliminate negative influence on healthy tissue. Results: Of the five extracts RPA demonstrated a significant (P < 0.05) anti-proliferative activity against estrogen receptor positive breast cancer cell lines (MCF-7). The proliferative phase was decreased by 18%, whereas, a significant increase in cell proliferation (about 27%) was observed for RPA at a concentration of 10 g/ml. PCL, CCL, HUL and PAL did not show marked inhibition of the proliferation of cell line MCF-7. Conclusion: These results give suggestive evidence that the plant extracts exhibit some correlation between the claimed ethnomedicinal uses and the cell proliferative activity. RPA extract includes chemi- cal compounds with estrogen-like activity and validates its potential use as anticancer agent, particularly against breast carcinoma; provided important information potentially helpful in drug designing and dis- covery. Further studies will involve the isolation of anti tumour compounds in RPA by LC–MS and detailed mechanism of anticancer activities. © 2011 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Natural products have historically and continually been inves- tigated for promising new leads in pharmaceutical development. Cancer is a major public health problem worldwide with mil- lions of new cancer patients diagnosed each year and many deaths resulting from this disease. Chemotherapy remains the principal mode of treatment for various cancers. Tamoxifen, a non-steroidal anti-estrogen drug, is used in the treatment of estrogen receptor (ER) – positive breast cancer patients and as chemoprevention in high risk women (Fisher et al., 2005), but is not effective against ER negative breast tumors (Gupta and Kuperwasser, 2006). Cancer cells are characterized by unregulated growth, as well as insuffi- cient and inappropriate vascular supply (Tomida and Tsuruo, 1999). ∗ Corresponding author. Tel.: +234 8073184488. E-mail address: faloabi@uniben.edu (A. Falodun). Moreover, a core of cells was subjected to micro environmental stress conditions, and has decreased apoptotic potential through genetic alterations, thereby resulting in resistance to apoptosis (Kaufman et al., 2002). Breast cancer is a cancer that starts in the tis- sue of the breast. It could be invasive or non invasive. The incidence of breast cancer in developing countries is on the increase due to many underlying factors such as birth control, sliding to Western culture, lifestyle, lack of facilities for early detection, poor fund- ing by government and international bodies. Adjuvant hormonal treatments such as tamoxifen are an essential part of the treat- ment regimen for early breast cancer, used to prevent recurrence. Hot flashes and night sweats are the most frequently occurring side effects, with up to 80% of women taking tamoxifen reporting them as troublesome. With nearly 46,000 new diagnoses of breast cancer annually in the United Kingdom and over 1 million worldwide, the problem is widespread, with estimates of over 100,000 women in the UK experiencing these symptoms at any given time (Love et al., 1991; Langer, 1996; Hunter et al., 2004). The use of plants or plant 0378-8741/$ – see front matter © 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2011.07.023