Cytotoxic and Apoptotic Induction Potential of Extracts from Fermented Citrullus vulgaris Thunb. Seeds on Cervical and Liver Cancer Cells

Abstract

The anti-cancer activities of many fermented foods and beverages are now scientifically established. Ogiri-egusi is a condiment prepared from fermentation of Citrullus vulgaris (melon) seeds and consumed in many countries of West Africa. Its anti-oxidative and anti-hyperlipidaemic properties have been reported. This study investigated the anti-cancer activities of the aqueous and methanolic extracts from ogiri-egusi. Cytotoxicity was investigated using the MTT and colony-formation inhibition assays while flow-cytometer based Apopercentage assay was used to quantify apoptosis in extracts-treated cervical and liver cancer and normal human fibroblast cells. The inhibitory concentration responsible for killing 50% of cells after 24 h by the aqueous extract in KMST-6, HeLa, and Hep-G2 cells were estimated at 1.610, 1.020, and 1.507 mg/mL respectively. While these values reduced with increasing incubation time in cancer cells it increased in the non-cancer cell. Furthermore, the extract significantly induced apoptosis in HeLa (97 ± 0.18%) and Hep-G2 (73 ± 6.73%) cells. These findings were corroborated by cells morphologic presentations and inhibition of colony formation assay. These findings suggest that the aqueous extract from fermented Citrullus vulgaris seeds might be a nutraceutical with potential anti-cancer properties.

Keywords:

• anti-cancer
• apoptosis
• fermented condiment
• MTT
• ogiri-egusi

Declaration of interest

The authors declare no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Additional information

Funding

The corresponding author is grateful to the African-German Network of Excellence in Science for the Intra-Africa mobility grant awarded her and for funding part of this study.

Notes on contributors

Rachael Aderonke Ayo-Lawal

Dr Rachael Aderonke Ayo-Lawal holds a PhD in Biochemistry. She has investigated on the possible health and nutraceutical benefits of two locally fermented condiments (fermented C. vulgaris and P. biglobosa seeds). She is currently a Researcher at the National Centre for Technology Management, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria.

Omolaja Osoniyi

Omolaja Osoniyi is an Associate Professor of Biochemistry in the Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife, Nigeria. His research interests include novel anticancer agents, functional foods for health and marine natural products.

Nicole Remaliah Samantha Sibuyi

Dr Nicole Sibuyi's core areas of research include molecular biology, cancer research and biotechnology. She also has skills and expertise in nanotechnology, targeted drug delivery, recombinant DNA technology as well as green technology.

Mervin Meyer

Prof. Mervin Meyer holds a PhD in Biochemistry from the University of the Western Cape. His research interest involves development of nanostructured materials for application in therapeutics and diagnosis. Applications in therapeutics entail the development of nanotherapeutics for the targeted removal of diseased cells through the induction of apoptosis.

Okobi Ekpo

Associate professor Okobi Ekpo is an anatomical scientist with vast experience. Currently, his laboratory-based research interests include investigation of potential neuroprotective and therapeutic effects of plant-derived bioactive compounds using in vivo and in vitro models of disease conditions. Some of the techniques used in his laboratory includes tissues culture, cytotoxicity, oxidative stress assessment among others.