Neuro-protective Activity of Pulicaria glutinosa in Oxidative Stress -induced Neurotoxicity in Zebrafish Embryos
Pulicaria is a genus of flowering plant in the Asteraceae family. It contains over 100 species. In this study the crude extract was prepared from the fresh leaves of P. glutinosa and further fractionated into three solvent to solvent fractions. The zebrafish (Danio rerio) embryos were treated with these extracts to explore the developmental toxicity. The crude extract did not show any significant toxicity; however, hexane fraction induced severe neurotoxicity in zebrafish embryos at 5 μg/mL. The brain formation was severely impeded and sever apoptosis was observed in treated embryos. The methanol fraction on the other hand did not produce any toxicity in zebrafish embryos even at 100 μg/mL. The antioxidant profile revealed that the methanol fraction exhibited highest antioxidant activity followed by chloroform fraction, while hexane fraction did not show any antioxidant activity. Due to high antioxidant activity the methanol fraction was used to rescue the oxidative stress induced neurotoxicity in zebrafish embryos. The methanol fraction not only rescued the neurotoxicity induced by hexane fractions but also protected the ethanol induced neurotoxicity in zebrafish embryos. The neuro-protective effect of methanol fraction could be due to high antioxidant content. This is the first study reporting a new activity of P. glutinosa as neuro-protectant in vivo and a potential therapeutic use in neurodegenerative diseases where pathogenesis is due to oxidative stress. Moreover, this study also reports for the first time the effect of antioxidant activity during embryonic development especially in zebrafish
