Supergrass II: The Cytotoxicity of Lemongrass Essential Oils on Colorectal Cancer Cells
Yichen Zhang
A.R. MacNeill Secondary
Floor Location : M 206 H

Cancer, defined as the uncontrollable division of abnormal cells, is a set of virulent diseases that ravage the global population. Annually, over 7 million lives are claimed by the pernicious disease, while 15 million new diagnoses are made. Colorectal cancer amounts to about 13.8% of all cancer diagnoses in Canada, and is considered the third most common cancer in both men and women. This cancer stems from the colon (large intestines) or the rectum (end of the colon), and usually begins in the glands in the lining. Almost all colorectal cancers also begin as benign polyps, which slowly mutate into the deadly disease.nnThis experiment seeks to investigate the ability of lemongrass essential oils to initiate programmed cell death in colorectal cancer cells. This was done by testing the effects of lemongrass essential oils on the Human Colorectal Adenocarcinoma cell line (LoVo), and the Human Cervix Adenocarcinoma cell line (HeLa), which was used as a comparison. IM-9, a Human B Lymphoblast cell line free of cancer was also used in this experiment to determine the cytotoxicity of lemongrass essential oils on regular cells.nnResults from the experiment has shown that this novel treatment induces apoptosis in colorectal cancer cells to an average of 41%. It was generally ineffective on the HeLa Cervix Adenocarcinoma, but the high cell death rate in the LoVo cells sheds positive light on this herbal remedy. Store bought citronella oil was also tested on the three cell lines, as a comparison to the lemongrass oil I made myself. Citronella and lemongrass are from the same family, and their essential oils share similar components, just at different concentrations. Unfortunately, the citronella oil proved to be highly cytotoxic to all the cell lines, causing 90%+ cell death in every sample, including IM-9, the healthy cells. Even though the citronella oil results showed that it wasn't very safe, the results obtained from the lemongrass essential oils suggests that it may be a well-balanced and safer alternative to the harmful treatments commonly used in the early stages of cancer.nnTo further explore how lemongrass essential oils could fight against colorectal cancer, a test will also be preformed on Streptococcus bovis and E.faecalis, the "predecessors" of colon cancer. The goal of this test will be to determine the inhibitory effects of lemongrass on the two dangerous types of gut bacteria.nnBecause the experiment testing the inhibitory effects of lemongrass essential oils is still in progress, I can only provide a general outline of what I am intending on doing. Both Streptococcus bovis and E.faecalis will be swabbed uniformly across culture plates and then, filter-paper disks, saturated with either citronella oil or lemongrass oil, will be placed onto the surface of the agar in every plate. Each plate will then be subjected to the Kirby-Bauer disk-diffusion test, and the zone of inhibition will be measured to determine each oil's effectiveness.The results will then be compared to the controls which are ciprofloxacin diluted to 0.1mg/ml and gentamicin diluted to 0.5mg/ml.