South Africa's uniquely rich floral diversity offers a large number of potentially useful and marketable products that have not been fully explored. Scientists in the Department of Botany at Rand Afrikaans University are particularly concerned to identify plants that have medicinal properties. The objective is to set the stage for their commercial exploitation and at the same time to husband them as a renewable resource.

Taxonomist Professor Ben-Erik van Wyk, who heads up the medicinal plants research team at RAU, points out that southern Africa has well over 30 000 species of higher plants. With this diversity it is not surprising to find that approximately 3000 species are used as medicines and, of these, some 350 species are commonly used and traded as medicinal plants.

As part of an initiative in association with SA Druggists, the research aim is to explore African medicinal plants as sources for new products, and then ensure that they are standardised in terms of active ingredients, toxicity levels, dosage forms, and method of preparation. The departmental laboratory is well equipped for chemical analysis. It is also versatile in that it deals with many aspects ranging across groups of plants, essential oils, alkaloids and so on.

'One has all sorts of different plant products to deal with,' says van Wyk, 'so we have to look at things in a different way to something which is manufactured with strict control over what goes into it.'

Giving a practical example, he says that if a manufacturer wanted to market a new tincture made from an indigenous plant that had never been commercialised before, he would need to ensure several things. The clone or form that he is using, for example, must have a favourable chemical profile. This not only relates to the active, or supposed active, ingredient, but also to toxicity and 'fingerprinting'. By law, it is required that each batch should be fingerprinted to ensure safety.

Another aspect of research is the development of techniques to grow on a commercial scale certain medicinal plants already being exploited. Many of them have not been cultivated before and their indiscriminate gathering has depleted their natural availability. If a good clone can be selected from the beginning, a farmer of medicinal plants can be well ahead of his competition in terms of yield or other criteria.

The herbal medicine team is now well advanced with the marketing of its first traditional product range under the brand name of Healer's Choice. This is currently in the process of evaluation by the Medicines Control Council (MCC). 'Health' shops and pharmacies will soon be able to offer Devil's Claw that claims to promote healthy muscles and joints, Real Buchu for healthier kidneys and bladder, uMhlonyane Buchu and Ginger for colds, and uMhlonyane Lengana for hayfever and stomach complaints.

The philosophy behind this project is to take these traditional medicines off the street into a more sophisticated marketplace. In the process the hope is to make indigenous medicinal plants more acceptable to the public at large and create job opportunities.

"If you look at any pharmacy in South Africa," van Wyk points out, "some 90% of the medicines on offer are exotic European formulations. I see no reason why we can't reverse this and have 90% indigenous medicines. For every European medicinal plant there is a local equivalent which is sometimes even better than the imported item." Looking at the cultivation of indigenous plants, honey bush tea (Cyclopia intermedia) is one currently under the spotlight. Some work has already been done on seed germination. There are different species of the genus and, says van Wyk, unfortunately the ones that give the best tea quality are the most difficult to establish. The seed physiology work done by the RAU botanists has effectively solved this problem and their methods are now prescribed and being used commercially to germinate seed and establish plantations.

As van Wyk stresses, recent surveys have shown that millions of medicinal plants are being sold in the informal market every day. This has been quantified and the annual value can best be described as "astronomical". Unfortunately, some of the plants are highly toxic. If one considers Boophane disticha, Gifbol in Afrikaans, Bushmen Poison Bulb in English, which is used, among other things, for treatment of boils and as an enema, the therapeutic dose and a lethal dose are not very far apart. Yet these products are openly sold on the streets.

"This creates a dilemma for the MCC in terms of regulation and control," says van Wyk. "The thinking at the moment is to create a new category in divisional medicine. This would have somewhat different requirements from those which apply to standard Western medicines, in order to get this type of product marketed with safety. This different approach is felt necessary because if the traditional medicines had to satisfy strict requirements and standards, the cost of meeting them would probably exceed the total value of the plant medicine.

"In other parts of the world, plant medicines are widely accepted," he says. "South Africa is far behind in terms of regulatory mechanisms to deal with the problem on the local front. My fear is that other people will see the opportunities and we will find them selling our plants in Europe and America when we are not allowed to sell them here. We are already several steps behind in the international market."