Comparison of antioxidant capacity of dry and wet sea cucumber Holothuria leucospilota tissue

Antioxidant activity as well as proximate analysis of sea cucumber Holothuria leucospilota was assessed. Samples were captured from Bostaneh coast, Hormozgan province. Body walls with/without internal organs were evaluated in fresh and rehydrated forms. Total protein, lipids, moisture, carbohydrate and ash were examined. In order to evaluate antioxidant activity, mathanolic, ethanolic and aqueous extraction as performed from body wall and internal organs in fresh and rehydrated tissues using malondialdehyde lipid peroxidation and total phenols methods. The results revealed that the moisture of samples was significantly (p<0.05) decreased after rehydration and the protein and lipid ratios were increased in samples. The results of malondialdehyde analysis showed that internal organs (gonads,  respiration tree, cuvierian organ) exhibit more antioxidant activity. The highest malondialdehyde (the lowest antioxidant activity) was measured in ethanolic extracts (1.01±0.2µmol/mg of dry weight), and the lowest malondialdehyde (highest antioxidant activity) was measured in wet internal organs (0.43±0.03µmol/mg of dry weight). Highest total phenol was measured in methanolic extracts of wet body wall (1.17±0.01 mg gallic acid equivalent per gram of sample in dry weight) and lowest total phenol was measured in ethanolic extracts of wet internal body extract (0.26±0. mg gallic acid equivalent per gram of sample in dry weight). The difference in results of antioxidant test and total phenol assay revealed that antioxidant properties of sea cucumber were originated from other components rather than phenolic compounds. Bioactive antioxidant compounds observed especially in the internal organs of sea cucumber H. leucospilota might be further screened as pharmaceutical precursors.