Inhibitory Activity of Juniperus communis on 12(S)-HETE Production in Human Platelets

Extracts of Juniperus communis L. (Cupressaceae) have been evaluated for their inhibitory activity on human platelet-type 12(S)-lipoxygenase [12(S)-LOX]. The methylene chloride extracts of Juniperi lignum, Juniperi pseudo-fructus and the ethyl acetate extract of Juniperi pseudo-fructus showed a significant inhibition on the production of 12(S)-HETE [12(S)-hydroxy-5,8,10,14-eicosatetraenoic acid] at 100 μg/mL (54.0 ± 6.73, 66.2 ± 4.03 and 76.2 ± 3.36 %, respectively). From the methylene chloride extract of the wood, cryptojaponol and β-sitosterol were isolated as compounds with inhibitory activity (inhibition at 100 μg/mL = 55.4 ± 2.80 % [IC50 = 257.5 μM] and 25.0 ± 2.15 %, respectively). In addition, a lipid fraction containing unsaturated fatty acids contributed to the in vitro activity of the crude extract.