Effect of Ocimum basilicum L. on cyclo-oxygenase isoforms and prostaglandins involved in thrombosis

Ethnopharmacological relevance

Ocimum basilicum L. (OBL) is a plant used in traditional Uyghur medicine for the treatment and prevention of cardiovascular disease. In previous studies we had found an antihypertensive and antithrombotic effect suggestive of an effect on prostaglandins, which we attempt to document here.

Materials and methods

6-keto-PGF₁α, the metabolite of prostacyclin, and PGE₂ were measured in the supernatant of human umbilical vein endothelial cells (HUVEC) and basal or LPS-stimulated mouse coeliac macrophage cultures exposed to OBL ethanol (OBL-E) extracts and petroleum ether, chloroform, ethylacetate and butanol (PE, C, EA, B) fractions. In addition, 6-keto-PGF₁α and thromboxane B2 (TXB2) were measured in a rat model of thromboangiitis obliterans exposed or not to OBL.

Results

Short-term exposure to OBL-E dose-dependently increased 6-keto-PGF₁α from HUVEC, and long-term (24 h) exposure decreased it. OBL-C and OBL-B increased 6-keto-PGF₁α, whereas the other fractions tended to decrease it after 24 h exposure. The extract and all fractions decreased basal and stimulated PGE2 production, but only OBL-EA and OBL-B reduced PGE2 in stimulated cultures to concentrations below the unstimulated values (P<0.05). In vivo OBL increased 6-keto-PGF₁α and decreased TXB2.

Conclusion

OBL and its extracts increased 6-keto-PGF₁α and reduced PGE2 and TXB2 production in a dose and time-related manner. This could indicate simultaneous inhibition of COX-2 and stimulation of endothelial COX-1. The butanol fraction seemed most promising in this respect.