Comparative pharmacological investigations of Allium ursinum and Allium sativum.

Extracts of wild garlic (Allium ursinum) and garlic (A. sativum) with defined chemical compositions were investigated for their in vitro inhibitory potential on 5-lipoxygenase (LO), cyclooxygenase (CO), thrombocyte aggregation (TA), and angiotensin I-converting enzyme (ACE). The inhibition rates as IC50 values of both extracts for 5-LO, CO, and TA showed a good correlation with the %-content of the major S-containing compounds (thiosulfinates and ajoenes) of the various extracts. In the 5-LO and CO test the garlic extracts are slightly superior to the wild garlic extracts whereas, in the TA test, no differences could be found. In the ACE test the water extract of the leaves of wild garlic containing glutamyl-peptides showed the highest inhibitory activity followed by that of the garlic leaf and the bulbs of both drugs. The comparative studies underline the usefulness of wild garlic as a substitute of garlic.

A new method for the in vitro screening of inhibitors of angiotensin-converting enzyme (ACE), using the chromophore- and fluorophore-labelled substrate, dansyltriglycine.

In our search for antihypertensive plant constituents, we developed a new in vitro assay for the detection of angiotensin-converting enzyme inhibitors in plant extracts. The chromophore- and fluorophore-labelled tripeptide dansyltriglycine is used as substrate, which is cleaved by the enzyme into dansylglycine and diglycine. The product dansylglycine and unreacted substrate are separated and quantified by reversed phase high performance liquid chromatography with UV detection. This target-directed enzyme assay is very specific, highly sensitive and reproducible, and lends itself very easily to automation.