Investigation of the Antioxidant Activity and Phenolic Compounds of Andricus quercustozae Gall and Host Plant (Quercus infectoria)

Abstract

Andricus quercustozae (Bosc, 1792) is a cynipid gall wasp, whichinduces gall on oaks (Quercus spp.). It is known that both cynipid galls andoaks are used in traditional medicine. In this study, some biologicalcharacteristics of various extracts (acetone and ethanol) of A. quercustozaeasexual gall and its host plant, Quercus infectoria Olivier, were investigated.The antioxidant capacities of the extracts were evaluated using radicalscavenging activity (ABTS and DPPH assays), the ?-carotene-linoleic acidmethod, the phosphomolybdenum method, and the reducing power (CUPRACmethod). Total phenolics, flavonoid and tannin contents were measured in thegall and the oak leaf extracts. Moreover, ethanol extracts of the gall and thehost plant were evaluated using HPLC for the composition of phenolics.Generally, the gall extracts (acetone and ethanol, respectively) exhibited thestrongest radical scavenging (DPPH, IC50 value of acetone extract: 11.00?g/mL and IC50 value of ethanol extract: 8.67 ?g/mL; ABTS, 52.27 ?g/mL and44.97 ?g/mL) and antioxidant activities with the highest level of phenolics. Theantioxidant activity of the gall extracts was in the range of 80.74 to 87.49 % for?-carotene-linoleic acid method, while and it was ranged from 75.68 to 78.20mgAEs/g for phosphomolybdenum method. In the results of some antioxidantmethods (ABTS and ?-carotene-linoleic acid), it is observed that the host plantextract has values close or high to the gall extract. In this context, our resultssuggested that the cynipid gall extracts could be used as a natural agent in food,medicinal and pharmaceutical applications.