Title : Synergistic antioxidant capacity of grafting gallic acid onto chitosan nano particles against ochratoxin A toxicity in African catfish, Clarias gariepinus
This study was designed to prepare and characterize enzymatic modified chitosan nanoparticles (CSNPs) with gallic acid (GA) or octyl gallate (OG) in average size around 90 nm , with positive charge and high scavenging activity especially GA-CSNPs and to evaluate their protective role against ochrtoxin A (OTA) toxicity in African catfish, Clarias gariepinus. In the in vivo study, catfish were divided into 8 groups and treated for 3 weeks as follow: the control group, OTA-treated group (1 mg/kg b.w.), the groups treated with CSNPs, GA-CSNPs or OG-CSNPs (280 mg/kg b.w.) alone or in combination with OTA. Blood, liver and kidney samples were collected for different analyses. OTA induced significant biochemical alterations accompanied with oxidative stress in the hepatonephric tissues, DNA fragmentation in the kidney was significantly increased. Co-treatment with OTA plus the different CSNPs resulted in a marked enhancement in all tested parameters, which was more pronounced in the group treated with GA-CSNPs. It conclusion, grafting of GA or its ester enhanced the properties of CSNPs. Moreover, GA-CSNPs showed strong scavenging properties than OG-CSNPs due to the blocking of carboxyl groups responsible of the scavenging activity in OG.