Evaluation of Toxicity and Antioxidant Activity of the Ethanolic Extract from Ulva Lactuca

Ulva lactuca (sea lettuce) is a popular food for consumers and has high nutritional value. It has also been found to be a source of health-promoting substances, including a high amount of proteins which can be utilized as a future plant-based functional ingredient in the food industry. However, before extensive applications in the aforementioned fields, it is crucial to ensure the extracts’ biological-pharmacological activities and their safety. In this study, we evaluated the cytotoxicity, genotoxicity, and antioxidant activity of the ethanolic extract of the sea lettuce extract.We tested cytotoxicity by MTT assays on 5 cell lines, including fibroblast (L929), macrophages (RAW 264.7), hepatocytes (FL83B), keratinocytes (HaCaT) and normal colon (CCD-18co) cells. Genotoxicity of the extract was tested by comet and micronucleus assays on human lymphoblast cells (TK6). Our results demonstrated at a concentration lower than 50 µg/mL the extract did not show any cytotoxicity as well as genotoxicity. The extract was shown to possess high antioxidant capacity by DPPH and ABTS scavenging at the EC50 value of U. lactuca extracts was 631.84 ± 5.64 and 330.35 ± 19.49 μg/mL, respectively. Therefore, the extract may be safely used as an ingredient for food, that should help to ensure food security for humans in the future, as well as for cosmetic, pharmaceutical and other health-promoting products. HIGHLIGHTS Ulva lactuca extract displayed strong antioxidant activity. Neither cytotoxicity nor genotoxicity to cell lines are seen in the ethanol extract of lactuca. GRAPHICAL ABSTRACT