15-lipoxygenase inhibition, superoxide and hydroxyl radicals scavenging activities of Cedrus brevifolia bark extracts.

Cedrus brevifolia (Hook. f.) Henry, a species endemic to Cyprus, has not been studied regarding its constituents and potential biological activities.

METHODS

A crude extract from Cedrus brevifolia bark and its four fractions (diethyl ether, ethyl acetate, n-butanol and aqueous fractions) were investigated regarding their capacity to inhibit 15-lipoxygenase and scavenge reactive oxygen species (superoxide anion and hydroxyl radicals). Catechin was used as positive control in all antioxidant assays.

CONCLUSIONS

In the superoxide anion radical scavenging assay, the crude extract showed the highest activity (EC50 = 57.73 +/- 1.25 microg/mL) comparable to that of the positive control, catechin (EC50 = 52.60 +/- 1.65 microg/mL). All other fractions exhibited noticeable scavenging effects against superoxide radical, their EC50 values ranging from 76.33 +/- 3.50 to 91.06 +/- 4.45 microg/mL. The ethyl acetate and n-butanol fractions were the most active in the hydroxyl radical scavenging (EC50 = 580.20 +/- 18.72 and 792.10 +/- 15.36 microg/mL, respectively) and 15-lipoxygenase inhibition assays (EC50 = 34.0 +/- 0.9 and 40.96 +/- 0.45 microg/mL, respectively).

CONCLUSIONS

Cedrus brevifolia bark is a valuable source of compounds with reactive oxygen species and 15-lipoxygenase inhibitory activities. These results support further studies for the identification and isolation of the bioactive constituents.