In Vitro Neuroprotective Effect of Shikimic Acid Against Hydrogen Peroxide-Induced Oxidative Stress

Shikimic acid (SA), originally extracted from Illicium verum Hook. fil., is an indispensable starting material for the synthesis of the antiviral drug Oseltamivir (Tamiflu(®)) with very limited number of studies regarding its biological effects in vitro. Therefore, we here evaluated the thermoanalytical profile, redox properties, and in vitro effects of SA on human neuronal-like cells (SH-SY5Y). The thermoanalytical profile of SA was studied by using differential scanning calorimetry (DSC) and thermogravimetry/derivative thermogravimetry (TG/DTG) characterization. Both antioxidant potential and in vitro lipoperoxidation levels were analyzed. Cell viability and intracellular reactive species (RS) production was determined by DCF and SRB assays, respectively. Our results show in vitro antioxidant activity of SA without exerting cytotoxic effects on SH-SY5Y cells at tested concentrations of 10 nM, 10 μM, and 10 mM. In addition, SA protected the cells against H2O2-induced toxicity; effect that could be related, at least in part, with decreased intracellular RS production and its antioxidant potential. The present study shows evidence for neuroprotective actions of SA against oxidative stress-induced toxicity on SH-SY5Y cells, inviting for further investigation about its potential use in the context of oxidative stress-associated neurodegenerative diseases.