MEDICINAL PLANT RESEARCH IN NEW ZEALAND

Medicinal plant research and commercial production is in its infancy in New Zealand. The New Zealand environment provides excellent growth conditions for many of the plant species used as medicinal herbs in Europe and a significant number have become weeds over the past 150 years of European settlement. Some of these naturalized species such as sweet briar and hawthorn can be considered untapped resources.

The medicinal plant research program is composed of two main areas (a) research on medicinal plants which have known international markets, (b) research on plant extracts and the search for new bioactive compounds. Ten medicinal plants, Echinacea purpurea, E. pallida, E. angustifolia, Panax ginseng, P. quinquefolium, Hydrastis canadenis, Glycyrrhiza glabra, G. uralensis, Silybum marianum, and Valeriana officinalis are the subjects of the current program. Research is focused on production and quality assessment. Research is most advanced on Echinaea purpurea, valerian and ginseng with limited information on licorice, goldenseal and milk thistle. Research has shown that the former three species can all be successfully grown and some commercial production has begun. Analytical techniques to measure alkamides in Echinacea and valtrates and valerenic acid in valerian have been perfected. This will enable crop production and post harvest systems to be assessed in terms of crop quality.

The major plant extracts program is focused on searching the New Zealand flora for new bioactive products. New antifungal, antitumour and insecticidal compounds have been discovered. Recent research has described the level of prostratin in the native species, Pimelea prostrate, and the concentration of taxol and other taxanes in the introduced Irish Yew (Taxus baccata).