Ligustrum vulgare L. and its utilization as anti-inflammatory remedy in folks medicine

The leaves of L. vulgare L. (common privet, Oleaceae) were well known in the Mediterranean historical medicine for their oropharyngeal anti-inflammatory effect against aphthae. Potential synergy between secoiridoidic (oleuropein) and flavonoidic components may play a central role in anti-inflammatory and probably antioxidative effect of this plant. It seems, anti-inflammatory activity depends on the total content of polyphenolic compounds. Lipoxygenase (LOX, EC 1.13.11.12) is a key enzyme in biosynthesis of leukotriens and lipoxins, which play an important role in pathophysiology of several inflammatory diseases. LOX catalyses the dioxygenation of polyunsaturated fatty acids with content of cis, cis-1,4-pentadiene structure by formation of hydroperoxides which are metabolised to mediators of inflammatory and allergic responses¹. The aim of this study was to monitor the inhibitory effect of L. vulgare infusions (10mg/10mL), oleuropein and echinacoside, a caffeoyl derivate (3–10×10^–5 mol.l^–1) on LOX activity. The fresh extracts from leaves of L. vulgare and LOX isolated from cytosolic fraction of rat lungs were used. The activity of LOX was determinated using a spectrophotometric method, expressed in percentage of inhibition and as IC₅₀. Also the kinetic type of inhibition was determined. The result showed that all studied compounds had an inhibitory effect on LOX activity. The highest inhibition was observed at 10×10^–5 mol/L. On the basis of this inhibitory effect, we suggest that these compounds have potential anti-inflammatory and antioxidative properties. Additionally, they provide support to the popular and ethnomedical descriptions of the utilization of privet as anti-inflammatory remedy in the Mediterranean area.

Acknowledgements: VEGA grant MS SR 1/0145/10, MS SR 1/0145/10, 1/0089/10.

References: 1. Funk, C.D. (2006) Arterioscler Thromb Vasc Biol 26p.1204–1206.