Phytochemical Evaluation, Antioxidant Activity and Toxicity of Paeonia daurica ssp. macrophylla Root

Background and objectives: Paeonia daurica ssp. macrophylla, is an herbaceous and perennial plant which belongs to Paeoniaceae family. Two species of this plant grow in northern parts of Iran. The roots in powder form have been used in Persian traditional medicine for treatment of epilepsy, nightmares and gynecological diseases. Several biological activities such as antioxidant and anti-tumor effects of Paeonia species have been reported. Methods: methanol-water (80-20) extract (total extract) was fractionated using n-hexane, chloroform and ethyl acetate. Antioxidant activity of the total extract and fractions were evaluated using DPPH and FRAP assays. Total phenolics content of the extracts was determined by Folin-Ciocalteu method. In addition, cytotoxic activity of the fractions was determined against brine shrimp larvae. Column chromatography with normal phase silica gel and preparative TLC were also used for the isolation and purification of compounds. Results: Evaluation of the results indicated that the ethyl acetate and chloroform fractions with IC50 values of 16.55, 23.9 µg/mL, respectively showed potent radical scavenging activity. As well, the ethyl acetate and chloroform fractions indicated the highest antioxidant power by FRAP assay. Due to the potent antioxidant activity, the chloroform fraction was chosen for further investigations. Three compounds were identified as benzoic acid, veratric acid and oleanolic acid by different spectroscopic methods. Conclusion: According to our findings in this study, the root of Paeonia daurica ssp. macrophyla has beneficial antioxidant activity without toxicity and the therapeutic use of this plant in traditional medicine can be somewhat justifiable.