Fatty Acid Composition and Cytotoxic Activity of Lipid Extracts from Nannochloropsis gaditana Produced by Green Technologies

Microalgae are alternatives and sustainable sources of omega-3 long chain-polyunsaturated fatty acids (LC-PUFA). However, the eco-friendly extraction of these bioactives remains unexplored. In this work, the use of enzyme-based methods in combination with ultrasounds was evaluated as green approaches to extract the omega-3 lipids from Nannochloropsis gaditana. Three commercial enzymatic solutions (Viscozyme(®) L, Celluclast(®) 1.5 L, and Saczyme(®)) were investigated, and results were compared with the traditional Folch method. A promising extraction approach was developed by using Saczyme(®), achieving a lipid yield of 25.7% ± 0.5, comparable to the traditional method (27.3% ± 0.7) (p > 0.05). Similar omega-3 content was found by GC–MS analysis for both lipid extracts (30.2% ± 2.4 and 29.3% ± 0.8 for the green and the traditional method, respectively), showing that the green approaches did not affect the fatty acid profile. Moreover, the cytotoxic activity of produced lipids was assessed by comparing human colon cancer cells (HCT-116) and epithelial nontumorigenic immortalized cells (HCEC-1CT). Results suggest that the lipid extracts have a selective effect, reducing the viability of the colon carcinoma cells but not the nontumorigenic cells. Thus, this study provides new eco-innovative approaches for extracting the omega-3 LC-PUFA from microalgae with promising biological properties.