Screening for antioxidant activities of several medicinal plant extracts and their effects on glutathione-s-transferase activity

Sağdıçoğlu Celep, Adviye Gülçin
The consumption of fresh fruits, vegetables, and medicinal plants are known to be associated with a long life span and low incidence of oxidative stress related diseases such as Alzheimer̕s, Parkinson̕s, cancer, aging and cardiovascular diseases. Fitotherapeutic effects of medicinal plants is virtually attributable to their phenolic compounds with low cytotoxicity. In this study, plants used in Anatolian folk medicine for their effects such as antiinflammatory, antiulcer, antipyretic, fertility, analgesic and aphrodisiac, namely Aesculus hippocastanum L., Papaver bracteatum L., Urtica urens L., Gundelia tournefortii L., Prangos ferulacea L., Chaerophyllum macropodum Boiss., Heracleum persicum Desf., Allium vineale L., Aconitum cochleare Woroschin, Rheum ribes L., Ferula rigidula DC., Rosa heckeliana Tratt, were screened for their antioxidative effects. Antioxidant characteristics of the specified plants were studied using lipid peroxidation inhibiton and DPPH radical scavenging methods. Total phenolics content and their effects on glutathione-S-transferase activity of the plants were further investigated. Rheum ribes L, Ferula rigidula DC, Rosa heckeliana Tratt., Prangos ferulacea L. were found to be very effective antioxidants and also effective inhibitors for glutathione-S-transferase activities among the plants. Rosa heckeliana Tratt. root extracts exhibited very high total phenolics content (0.7 mg/mg of extract) and antioxidant activity with IC50 values of 11.2 æg/mL and 5.1 æg/mL for DPPH scavenging and lipid peroxidation inhibition, respectively. Ferula rigidula DC was identified as the most potent inhibitor for glutathione-S-transferase activity, with IC50 values of 49 æg/mL.