The properties of Hoodia as a “non-food” were investigated by the CSIR’s Division of Food Science and Technology in the 1960’s, but drew no interest as the research programme focused on food from the wild and the ethnobotany of the Kalahari San. From 1983 – 1986, molecular structures of chemicals in Hoodia were elucidated, a steroidal glycoside identified. The CSIR’s scientists, working with Phytopharm, isolated what they believed to be an active ingredient in Hoodia gordonii, a steroidal glycoside, which they named P57. After obtaining a patent in 1995, the CSIR licensed P57 to Phytopharm.
However, as obesity and dieting began to take more prominence as a global and serious health condition in the 1980’s and onward, interest in P57 began to increase.
During 1991 – 1996 Mr Vinesh Maharaj the carried out a “secret” PhD to elucidate the chemical structure of P57 and found that it was possible to synthesise the compound, but only through 26 complex steps. At this point, the compound was patented. The P57 patent details:- Van Heerden FR, Vleggaar R, Horak RM, Learmonth RA, Maharaj V, Whittal RD. “Pharmaceutical compositions having appetite suppression activity.” (1986).
During this time, methods of grow the plant in vitro were also investigated, but were dropped as the outside of the plant had too many microbial contaminants. This meant that all Hoodia plants had to be grown from seed or cuttings in an outdoor setting.
The patent was then licensed to Phytopharm UK, with Pfizer as a partner, and this group and the CSIR began to carry out greenhouse and field trials to determine the best way to grow the plant, including fertilizer and herbicide regimes. This work also involved investigations into how to best harvest and prepare seeds, and how to transplant the seedlings. The initial seed germination work was done by Mr Ralph Peckover in greenhouses in Pretoria and then in field plantings in the Upington area.
Pfizer also conducted field trials on selected Hawaiian islands where there was a suitable low rainfall. Pfizer also did feeding trials with rats, dogs, and human subjects and all seemed OK at that stage. Subsequently Pfizer stated that their preferred manufacturing model was to work with the pure chemical, not with plants and products that had to be extracted from plants. So Pfizer returned the P57 patent to Phytopharm.
Phytopharm put the product and patent out on tender again, and was taken up by Unilever. Unilever paid R3 million for the rights to carry out basic research. They set up test sites in the northern Cape and got contract farmers to grow Hoodia between 2006 and 2008..
The P57 compound is present in Hoodia gordonii and Hoodia pilifera, as well as Hoodia krausii, although Hoodia gordonii had the compound in the highest quantities. These plant species are all very susceptible to fungi and water-logging and can only be grown where there is 250 mm or less rainfall per year, and the plant does best when temperatures are between 35 – 56 deg C. Under these temperatures, irrigation is needed to get the seedlings established. They need to be watered (drip or overhead irrigation) up to three times a day to get going. Weeds also proliferate under these conditions. The plants are very susceptible, both as small plants and as adult plants, to salt accumulation in the soil and so the quality of irrigation water has to be good.
Both the seedlings and adult plants are susceptible to many insect pests, as are most plants grown in a monoculture situation as Hoodia gordonii is. There is a range of weavils and stinkbugs that attack the seed pods, reducing seed yield, as well as a range of mealy bugs and thrips that would damage the plant so that fungi and bacteria gained a hold and destroy the plants.
During handling and transplanting, the small plantlets with their spines make holes in each other, which also quickly become infected by fungi and bacterial rot. Although the seed germinate readily and the plants is easy to grow in greenhouse condition, the cultivation of this plant on an agricultural scale in arid areas is very challenging.
After some of the basic horticultural methods were worked out, Phytopharm looked for agricultural partners and identified Carstens Farms/Boerdery, a big farming enterprise in the Upington area with many farms along the orange river. Test sites were set up in 1998, and irrigation, fertilizer and pesticide regimes were tested. A minimum regime of fertilizers and pesticides was sought to try and keep the cultivated material as “organic’ as possible for international markets.
In terms of cultivation, drought and stress increased the amount of P57 in the plants.
When plants were being field trialed in the Upington area, different ways of harvesting the plants were also investigated, e.g. whether it was better to pull p the whole plant or selectively cut off branches and wait for regrowth, noting that the plant reacted very well to being ‘pruned’, and all wounds dried and re-sprouted. This was selected as the most viable approach to harvesting the field-grown Hoodia material. As establishing new orchards of the plant from seed is very time consuming, with a high failure rate, it was obviously is better to leave the plants in situ and just remove branches, and allow the plant to re-sprout.
Under irrigation, the orchards of Hoodia plants have to be weeded, as grasses grew prolifically, smothering the plants. This was all very labour intensive, and under very harsh conditions. Day time temperatures in the Upington area can get up to 56 deg Centigrade, with soil temperatures being in the high sixties (Centigrade). Also, in terms of weeding and harvesting, the spiny nature of Hoodia makes for unpleasant work conditions.
Another complication is accidental genetic contamination by pollen from other non-P57 containing, yet closely related Hoodia species. If the taxonomic identification of source material is not rigorous, cross hybridisation could result in plants that only produced marginal amounts of P57.
Also, the transplanting of the small Hoodia plantlets (about a finger-size) was also very labour intensive. Small seedlings were grown in hothouses and then transplanted into the field. Small shade structures had to be placed over each small plant to allow the plant to become established. If the plants were not covered up in the initial weeks, they simply cooked in the heat. The transplanting of these plants into fields adding up to farms of 100 hectares was very labour intensive and unpleasant, and would no doubt add to the costs.
All in all, it would seem that the agronomy of Hoodia is very difficult and labour intensive, under severe environmental conditions (heat). The planting out of individual sees, which are only centimeters high, resulted in heavy losses, and is thus problematic. Other ways of planting out the seedlings would have been needed, if the project had continued.
However, once established , the stands of Hoodia grow incredibly well. It is a spectacular sight to see tens of hectares of very arid landscape planted out with Hoodia, the huge pink flowers looking like satellite dishes. Apparently the smell of these flowering plantations “is not very bad,” although the plants do rely on flies for pollination in the wild and they smell like carrion.
The Northern Cape Development Agency was approached for a funding partnership between themselves and Unilever to establish a drying plant in Upington, and a processing plant in Paarl, both of which were exciting developments for regions that need new enterprise and economic development. These projects have now collapsed, once Unilever announced its ‘toxicity’ findings.
Unilever paid out contract farmers, according to clauses in their contracts so the participating farmers will not lose out financially, except in their expectations to be part of a bigger industry. Although Unilever reported on P57 toxicity, there may be other reasons why the project was terminated, like the high cost of producing Hoodia in the area areas where cultivation is labour intensive and requires extensive irrigation infrastructure.
This development was also devastating to Northern Cape, as they also had expectations surrounding job creation and economic development linked to the Upington drying plant and be sole suppliers of this unique desert product. The patent reverted to Phytopoharm.
The Phytopharm Chairman, Alistair Taylor, commented at the time that over the years, Phytopharm had generated a considerable body of pre-clinical and clinical data on Hoodia and while Hoodia was not suited for a Unilever branded food and beverage product, Phytopharm committed itself to continue exploring alternative product formats for the commercialisation of Hoodia.