Active Compounds and Oxidative Defense of Cladophora spp. in Hybrid Catfish

Abstract

Cladophora spp., a freshwater alga, was evaluated for its antioxidant activity and active compounds. The alga collected from natural source (NanRiver) and cultivated alga were compared in terms of radical inhibition ability and phenolic compounds; the results showed no significant differences in these evaluated quantities. The active compounds of alga consisted of several phenolic compounds, including isoquercetin, catechin, tannic acid, hydroquinin, quercetin, rutin, gallic acid and kaempferol. The alga collected from the natural source was further evaluated for its oxidative defense ability in hybrid catfish (Pangasianodon gigas × Pangasianodon hypophthalmus). Fish-feed supplemented with 0%, 2.5%, 5% and 10% alga was fed to hybrid catfish, which was cultured in cage for 7 months. The fish fed with 5% and 10% alga supplemented feed had significantly increased growth and decreased level of lipid peroxidation in liver when evaluated at the 5th and 7th months. However, all groups that received alga supplement did not show significant changes in the level of glutathione in erythrocyte. The findings concluded that Cladophora spp. led to reduced oxidative stress in fish. Therefore, the alga has a potential to be used as a feed supplement in aquaculture.