Title: Synergistic antioxidant capacity of grafting gallic acid onto chitosan nano particles against ochratoxin A toxicity in African catfish, Clarias gariepinus

Heba S. Hamed

Ain shams University, Eygpt


Prof. Heba S. Hamed is currently working as Associate Professorof Fish Physiology in Zoology department, Faculty of Women for Arts, Science &Education, AinShams University, Cairo,Egypt. She had her doctorial of Philosophy of Science in 2012 and Master of  Science degree in 2010 from Ain Shams University, Cairo, Egypt. Prof. Hamed had a diploma in  biochemistry and physiology from Suez Canal University, Faculty of Science, Ismailia, Egypt in2014-2015. She also had a Professional diploma in Quality & Accreditation management systems 2015-2016. Her major research interests include Fish Physiology, Nano toxicology, Reproductive Toxicology, and Aquatic Toxicology. She has been  able to prove scientifically that extraction of some medicinal plants and used locally in fish diets contain pharmacologically active principles, capable of ameliorating fish reproductive dysfunctions and enhancing fecundity. Prof. Hamed is an editorial board member of International Journal of Ecotoxicology and Exobiology and Frontiers in physiology Journal. She is also a reviewer in Environmental Toxicology and Pharmacology, Natural Product Research Aquaculture and Fisheries, and many other International Journals.


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.