Genotoxic and Cytotoxic Activity of Aqueous Extracts of Croton membranaceus in Rodent Bone Marrow and Human Benign Prostate Hyperplasic Cells

Background: Croton membranaceus is a plant cherished by traditional healers in Ghana for its anti-prostate cancer properties. Its cytotoxic effect as well as safety has been proved. However, to the best of our knowledge, no study has been conducted to assess its genotoxic and cytotoxic potential using the rodent bone marrow and colony formation assays respectively.

Aims: This study is aimed at investigating the cytotoxic and genotoxic effects of the aqueous root extract of Croton membranaceus (CMARE) using the colony formation and rodent bone marrow assays respectively.

Study Design: This was an experimental study.

Methodology: To determine the cytotoxic effect, BPH-1 cells were seeded in 6-well plates at a density of 1.0 x 105 cells/well in 2 mL culture medium (plus 10% FBS) and incubated for 24 h. After treatment with 0, 1, 3 and 5 mg/ml of CMARE for 48 h, the cells were collected and further treated with fresh medium in the absence of CMARE, and reseeded into new 6-well plates at a density of 1.0 x 103 cells / well. After 10 days incubation, colonies were fixed in 10% formalin, crystal violet-stained and counted. Genotoxicity was determined by the bone marrow assay using 30 male Sprague-Dawley rats divided equally into three groups. Animals in the treatment, positive and negative control groups were administered 3000 mg/kg CMARE, N-nitroso-N-methylurea and saline respectively.

Results: Cytotoxicity significantly occurred at 3 and 5 mg/ml, compared to the control. The bone marrow assay showed a significant difference between CMARE-treated animals and negative controls when the polychromatic erythrocyte-normochromatic erythrocyte (PCE-NCE) ratios were compared. Furthermore, there was a positive correlation between CMARE-treated animals and positive controls when their micronucleated polychromatic erythrocytes (MNPCE) were compared, indicating similar genotoxic potential between very high CMARE doses and the positive control.

Conclusion: These results show that CMARE has both cytotoxic and genotoxic potential.