Evaluation of antioxidative, protective effect against H2O2 induced cytotoxicity, and cytotoxic activities of three different Quercus species

► Quercus (oak) species are the important source of phenolic compounds. ► Oak extracts exhibited strong radical scavenging activity. ► Extracts showed protective effect against H2O2 induced cytotoxicity in erythrocytes. ► Cytotoxicity against Hep-2 cancer cells was found for the antioxidative extracts. ► Quercus macranthera subsp. syspirensis gave the most bioactive extracts.