In vitro antioxidant and hepatoprotective activities of Paeonia emodi (Wall.) rhizome methanol extract and its phenolic compounds rich fractions

The present study aimed to quantify the total phenolic content in Paeonia emodi rhizome methanol extract and its fractions and then evaluate-the in vitro antioxidant and hepatoprotective activities of fractions rich in phenolic compounds. Maximum quantity of total phenolic content was observed in butanol (112.08 +/- 5.5 mg GAE/g dw) and chloroform fraction (107.0 +/- 3.5 mg GAE/g dw) followed by methanol extract (94.2 +/- 4.4 mg GAE/g dw), aqueous fraction (92.9 +/- 2.5 mg GAE/g dw), ethyl acetate (62.3 +/- 8.3 mg GAE/g dw) and n-hexane fraction (51.6 +/- 7.2 mg GAE/g dw). The fractions rich in total phenolic content were evaluated for in vitro antioxidant activity based on 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) scavenging assay. The butanol and chloroform fraction showed significantly (P<0.05) higher radical scavenging activity with IC50 values of 6.5 and 7.05 +/- 2.5 ppm respectively. Positive correlation (R square=0.95) was observed between total phenolic content and in vitro antioxidant activity. The fractions rich in phenolic compounds were also evaluated for their hepatoprotective activity in paracetamol intoxicated mice. Five days oral administration of these fractions at a dose of 300 mg/kg body weight restored the serum ALT, AST and ALP levels of paracetamol intoxicated mice to normal level. From the results of the present research it was concluded that the butanol and chloroform fractions of P. emodi rhizome methanol extract are rich in phenolic compounds and strong antioxidant and effective in attenuation of hepatotoxicity.