Synergy of Electrical Pulses and Black Pepper (Piper nigrum) Extracts for Effective Breast Cancer Treatment: An In Vitro Model Study

Abstract

In this research, the effectiveness of electrical pulse-mediated Piper nigrum (Black pepper) extracts against MCF-7, ER-positive human breast cancer cells were investigated. Initially, P. nigrum extracts were extracted by using the conventional (Soxhlet) and electrical pulse-assisted method. We assessed the phytochemicals present in both extracts by phytochemical screening tests and compared their total phenol contents and antioxidant activity with the conventional extract. FTIR and GCMS for untreated and treated extracts were also measured and compared. Electrically enhanced extracts (EE) resulted in an improvement of ∼41% in its antioxidant activity and ∼24% increase in their total phenol contents than untreated extracts. The cytotoxic activity of both extracts was determined by MTT proliferation assay in a dose-dependent manner. The results show that electrical pulse-assisted extracts have enhanced the bioactive compounds, with respect to untreated extracts, significantly promoted total phenols and antioxidant activity, which is correlated with increased MCF7 cytotoxicity. Furthermore, to enhance the uptake of extracts against plasma membranes, electrical pulses of different parameters (EP1 and EP2) were used. The results indicate cell viabilities of 27% with raw extract only, 12% with EE only, 7% with (EP1 + EE) and 6% (EP2 + EE) after 72h, indicating the potential of the synergetic effect of electrical pulses (EP) and enhanced extract (EE). On comparison, the enhanced extract showed viability of two times less than raw extracts, whereas when it is mediated with electrical pulses, there is a marked reduction in cell viability. This clearly indicates that the application of electrical pulses aids in achieving antioxidant and phenolic-rich extracts. Furthermore, this treatment is more appropriate to achieve maximum cell death, with less concentration of the extract to treat breast cancer.

Keywords:

• Antioxidant activity
• Breast cancer
• Cytotoxic activity
• Electroporation
• Phenol contents
• P. nigrum (Black pepper)

Acknowledgements

We would like to thank Dr. M. Rajmohan, Professor and S. Hariharan, Research Scholar, Department of Industrial Engineering, CEG, Anna University for their valuable help in performing statistical analysis. We also thank Dr. M. Sivanandham and Dr. E. Nakeeran, Department of Biotechnology, Sri Venkateshwara College of Engineering, Sriperumbudur, for allowing us to their laboratory to perform phytochemical experiments. This work was supported by Anna University, Tamil Nadu, India, under Anna Centenary Research Fellowship.

Additional information

Notes on contributors

S. Poompavai

S Poompavai received the BE degree in electrical and electronics engineering from Prince Shri Venkateshwara Padmavathy Engineering College, Anna University, India in 2013. She received her ME degree in high voltage engineering from the College of Engineering, Guindy, Anna University, India in 2015, and at present, she is a research student in the Division of High Voltage Engineering, Anna University, and Chennai, India. She has received Anna Centenary Research Fellowship Award. Her research interests include application of pulsed electric fields to cancer, modeling of breast cancer, enhancing the extraction of bioactive compounds, study of effectiveness of natural herbal sources as an alternative chemotherapeutic drug. E-mail: [email protected]

V. Gowri Sree

V Gowri Sree received her doctorate in high voltage engineering in 2008 from the College of Engineering, Guindy, Anna University, India. She is presently associate professor in the same university with over 25 years of teaching experience. She has contributed a chapter to the book, titled, “Electroporation-based Therapies for Cancer: From Basics to Clinical Applications” (Wood Head Publishing, 2014). Her current research topics are application of high voltage engineering for cancer treatment and enhanced bioactive compound extraction.