Saponification to improve the antioxidant activity of astaxanthin extracts from Penaeus sinensis (Solenocera crassicornis) by-products and intervention effect on Paracetamol-induced acute hepatic injury in rat

Abstract Astaxanthin (Asta) extracts from Penaeus sinensis by-products showed increased in vitro antioxidant activity after saponification as compared to the non-saponification Asta. The increases of geometrical Asta (activity order of 9-cis > 13-cis > all-trans) and Asta stereoisomers could be responsible for the improved antioxidant activities of saponification Asta. Non-saponification or saponification Asta (150 mg/kg) was administered in Sprague-Dawley rats via gavage daily for 14 days before paracetamol (PCM)-induced (400 mg/kg) acute hepatotoxicity. Pre-treatment with non-saponification or saponification Asta counterbalanced rats liver oxidative stress by PCM-induction through restoring reduced glutathione content, total superoxide dismutase and glutathione peroxidase activities. Moreover, Asta pre-treatment decreased glutathione-S-transferase-P (placental form) foci, p53 and p38 expressions as compared to the model group. Pre-treated with Asta up-modulated phase-II enzyme NAD(P)H: quinine oxidoreductase-1 or Hemoxygenase-1 expressions, indicating the nuclear erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) pathway for the non-saponification or saponification Asta to alleviate PCM-induced hepatotoxicity in rats.