Determination of the toxic activity of optimized extracts from Palmaria and Porphyra for the treatment of the ischemia/reperfusion injury
The ischemia/reperfusion (I/R) injury can cause rejections in organ transplantation surgeries due to the damage that Radical Oxigen Species (ROS) produce in the cells. It has been proved that natural antioxidants can reduce this damage. A lot of algae extracts show a noticeable antioxidant activity, but it is needed to test their toxicity before suggesting them as potential drugs. In this study, two toxicologic assays using human immortalized keratinocytes (HaCaT) and Artemia salina nauplii were carried out to test the toxicity of two extracts that showed antioxidant activity from Palmaria palmata and Porphyra sp. LC50 values of 7.843% (v/v) of extract concentration with P. palmata in the HaCaT assay and 3.2583% (v/v) in the A. salina assay were obtained, while 10.7463% (v/v) of extract concentration for the HaCaT assay and 6.5688% (v/v) for the A. salina assay were obtained for Porphyra sp. The No Observed Adverse Effect Level (NOAEL) obtained for each algae in each assay showed a significantly higher toxicity level in the P. palmata extract than in the Porphyra sp. extract (p < 0.05). Lastly, an index which considers both antioxidant activity and toxicity of each extract was proposed for predicting their in vivo efficiency, supporting the previous results, so Porphyra sp. extract was considered the most suitable for going ahead with the preclinic assays towards the development of a drug for treating the I/R injury.