(A) Effects of various concentrations of compounds 6 and 8 alone on cell viability. (B) Effect of various concentrations of compound 6 (0.001, 0.01, 0.1, 1 and 10 μmol/l) on cell viability in H₂O₂-induced SH-SY5Y. (C) Effect of various concentrations of compound 8 (0.001, 0.01, 0.1, 1 and 10 μmol/l) on cell viability in H₂O₂-induced SH-SY5Y. (D) Effect of various concentrations of compound 6 (0.001, 0.01, 0.1, 1 and 10 μmol/l) on LDH release in H₂O₂-induced SH-SY5Y. (E) Effect of various concentrations of compound 8 (0.001, 0.01, 0.1, 1 and 10 μmol/l) on LDH release in H₂O₂-induced SH-SY5Y. (F) Effects of compounds 6 and 8 on H₂O₂-induced morphological alterations in SH-SY5Y (×400). Values are expressed as means±S.D. from six individual samples.*P<0.05 against the H₂O₂ treated group.