I take a COX-2 inhibitor which probably raises my LOX-5. It's good to know that food and spices can lower LOX-5! Quercetin was the best in this study. It's in apples, onions, garlic, broccoli, etc.

Spice phenolics inhibit human PMNL 5-lipoxygenase

N. Satya Prasada, R. Raghavendraa, B. R. Lokeshb and K.A.K. Akhilender NaiduCorresponding Author Contact Information, E-mail The Corresponding Author, a
a Department of Biochemistry and Nutrition, Central Food Technological Research Institute, Mysore 570 013, India
b Lipid Science and Traditional Foods, Central Food Technological Research Institute, Mysore 570 013, India
Received 22 July 2003; accepted 19 November 2003. Available online 30 April 2004.



Abstract

A wide variety of phenolic compounds and flavonoids present in spices possess potent antioxidant, antimutagenic and anticarcinogenic activities. We examined whether 5-lipoxygenase (5-LO), the key enzyme involved in biosynthesis of leukotrienes is a possible target for the spices.

Effect of aqueous extracts of turmeric, cloves, pepper, chili, cinnamon, onion and also their respective active principles viz., curcumin, eugenol, piperine, capsaicin, cinnamaldehyde, quercetin, and allyl sulfide were tested on human PMNL 5-LO activity by spectrophotomeric and HPLC methods. The formation of 5-LO product 5-HETE was significantly inhibited in a concentration-dependent manner with IC50 values of 0.122–1.44 mg for aqueous extracts of spices and 25–83 μM for active principles, respectively. The order of inhibitory activity was of quercetin>eugenol>curcumin>cinnamaldehyde>piperine >capsaicin>allyl sulfide. Quercetin, eugenol and curcumin with one or more phenolic ring and methoxy groups in their structure showed high inhibitory effect, while the non-phenolic spice principle allyl sulfide showed least inhibitory effect on 5-LO.

The inhibitory effect of quercetin, curcumin and eugenol was similar to that of synthetic 5-LO inhibitors—phenidone and NDGA. Moreover, the inhibitory potency of aqueous extracts of spice correlated with the active principles of their respective spices. The synergistic or antagonistic effect of mixtures of spice active principles and spice extracts were investigated and all the combinations of spice active principles/extracts exerted synergistic effect in inhibiting 5-LO activity. These findings clearly suggest that phenolic compounds present in spices might have physiological role in modulating 5-LO pathway.

http://www.sciencedirect.com/science...faa1f6ef1f72c8