Krill oil extract suppresses cell growth and induces apoptosis of human colorectal cancer cells

Abstract

BackgroundColorectal cancer (CRC) is the third most common cancer in the world. The current available treatments for CRC include surgery, chemotherapy and radiotherapy. However, surgery is only useful when the disease is diagnosed at the earlier stage. Chemotherapy and radiotherapy are associated with numerous side effects that decrease the patients’ quality of life. Safer, effective alternatives, such as natural compounds, to chemotherapy are desirable. This study assessed the efficacy of free fatty acid (FFA) extract of krill oil on three human CRC cells lines.MethodsHCT-15, SW-480 and Caco-2 cells were treated with the FFA extracts of krill oil and fish oil for 48 h while treatments with the bioactive omega-3 polyunsaturated fatty acids (LC n-3 PUFA) of these marine oils, eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3) in comparison with a n-6 PUFA, arachnoid acid (AA, C20:4n-6) were up to 72 h at the concentrations of 50, 100, 150 and 200 μM. Effects of all the treatments on cell proliferation were assessed using a water-soluble tetrazolium-1 (WST-1) assay kit at 24, 48 and 72 h. Effects of FFA extract of krill oil and EPA on apoptosis and mitochondrial membrane potential were determined using commercial kits after 48 h of treatment.ResultsKrill oil extract inhibited cell proliferation of all three cell lines in the similar manner as fish oil extract. A significant cell apoptosis and increase in mitochondrial membrane potential were observed after the treatment with krill oil extract. EPA at the concentration of 200 μM reduced significantly the proliferation of HCT-15 and SW-480 at 24, 48 and 72 h. In addition, EPA treatment (100 and 200 μM) resulted in significant cell apoptosis in all three cell lines. No significant changes were observed after treatment with DHA and AA.ConclusionsOur results indicate that the FFA extract of krill oil maybe an effective chemotherapeutic agent to suppress proliferation and induce apoptosis in CRC cells through its bioactive constitute EPA. Although the exact mechanism of the pro-apoptotic properties of krill oil extract is unclear, mitochondrial pathway seems to be implicated.

Antarctic Krill (Euphausia superba) Oil: A Comprehensive Review of Chemical Composition, Extraction Technologies, Health Benefits, and Current Applications

“…Jayathilake et al. () also focused on the effects of FFA extract obtained from krill oil on the cell proliferation and apoptosis in three cell lines of human colon adenocarcinoma (HCT‐15, SW‐480 and Caco‐2 cells). Treatment with 0.12 μL FFA extract of krill oil in 100 μL DMEM for 48 hr resulted in inhibition effects on the proliferation of HCT‐15 and SW‐480 cells.…”

“…Chemotherapy and radiotherapy are important anti-cancer treatments by triggering apoptosis to block neoplastic inception or delay disease progression. However, they have numerous negative effects, such as myelosuppression, mucositis, dermatitis, and diarrhea (Jayathilake, Senior, & Su, 2016). The idea of using dietary nutrients that are capable of modulation of apoptosis has been raised as a potential anticancer therapy (Block, Patterson, & Subar, 1992).…”

“…Treatment with krill oil at the concentration of 20 μg/mL in Dulbecco's modified Eagle's medium (DMEM) for 48 hr resulted in a 29.9% inhibition of cell growth of SW480 (Zhu et al, 2008). Jayathilake et al (2016) also focused on the effects of FFA extract obtained from krill oil on the cell proliferation and apoptosis in three cell lines of human colon adenocarcinoma (HCT-15, SW-480 and Caco-2 cells). Treatment with 0.12 μL FFA extract of krill oil in 100 μL DMEM for 48 hr resulted in inhibition effects on the proliferation of HCT-15 and SW-480 cells.…”

Effects of Dietary Grape Pomace Supplementation on Performance, Carcass Traits and Meat Quality of Lambs

“…In particular, the n-6/n-3 ratio in meat has become of important significance in human nutrition, since consumption of meat enriched with long chain n-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is beneficial. The main benefits associated with EPA and DHA are their anti-inflammatory properties (18), cardiovascular protective effects (19) and reduction of the risks for specific types of cancer (20).…”

Effects of Marine Oils, Digested with Human Fluids, on Cellular Viability and Stress Protein Expression in Human Intestinal Caco-2 Cells

“…Krill oil digests also had a lower HHE to MDA ratio than cod liver and algae oil digests, but if there is a specific effect of HHE on the down-regulation of SOD2 levels is not known. Free fatty acids (FFA) extracted from krill oil was previously found to inhibit cell growth and induce apoptosis when added in undigested form to HCT-15, SW-480, and Caco-2 cells [ 45 ]. Our digests contain a mixture of FFA, as well as partially hydrolyzed TAG and phospholipids, but indeed the FFA could play a specific role.…”