Fig 3. Lipid peroxidation (LPO) inhibitory activities of sterols (1–5) isolated from the hexane extract of L. japonica and commercial cholesterol tested at 25 μg/mL.

Commercial antioxidants BHA, BHT and TBHQ used as positive controls at 1.8, 2.2 and 1.6 μg/mL. The oxidation of lipid was initiated by the addition of Fe²⁺ ions. The varying concentrations of positive controls used were to yield a comparable activity profiles between 50–100% by test compounds and positive controls alike. Vertical bars represent the standard deviation of each data point (n = 2).