Antiatherogenic effect of guava leaf extracts inhibiting leucocyte-type 12-lipoxygenase activity

► Leucocyte-type 12-lipoxygenase is the key enzyme for LDL oxidation and atherogenesis. ► We found that guava leaf extracts inhibited the catalytic activity of this enzyme. ► LDL oxidation by the enzyme-expressing cells was also suppressed by the extracts. ► Oral administration of the extracts decreased atherosclerosis in apoE-knockout mice. ► The active components in the extracts were identified as ethyl gallate and quercetin.