Thiobarbituric acid-reactive substances (TBARS) in vitro . A lipid-rich system was incubated with a free radical source (AAPH) and the effect of different concentrations of RMO on the lipoperoxidation was measured by quantifying TBARS. Control is incubation medium without AAPH; other groups contained AAPH alone or in the presence of different concentrations of RMO or its vehicle alone. Bars represent mean ± SEM. *p < 0.05, **p < 0.0001 (1-way ANOVA followed by Tukey’s multiple comparison post test).