Pharmaceutical plant

from Wikipedia, the free encyclopedia

Pharmaceutical plants (English: pharm crops ) are plants that have been modified by genetic engineering methods in such a way that they are

  • pharmaceutically active proteins , antibodies for diagnosis and therapy e.g. B. from cancer, produce vaccines or hormones that can then be used in medicines, or
  • produce important materials for pharmaceutical production or pharmaceutical laboratory work.

These substances produced in this way are called Plant-Made Pharmaceuticals ( PMP for short in the specialist literature ) and are a sub-group of biopharmaceuticals . They can either be directly usable in the plants or have to be extracted from them in the laboratory.

The production and cultivation of pharmaceutical plants (English: plant pharming ; drawn together from pharm and farming ) as an application area of ​​genetic engineering is a combination of so-called “ green genetic engineering ” (application of genetic engineering in agriculture; English term molecular farming ) with so-called “ red ” Genetic engineering ”(application of genetic engineering in medicine; the relevant branch of science is called pharmaceutical biotechnology ). The terms pharming or biopharming are very often incorrectly used for plant pharming - but also includes animal pharming , i.e. pharmacy , in addition to pharmaceutical plants - and plant molecular pharming - not only includes the production of medicinal substances.

Pharmaceutical plants belong to the so-called “second and third generation” of genetically modified plants, which should not only be of direct benefit to producers, but also to consumers. These plants should z. As health-compatible be taste better, be more durable, protect against disease or even as "pharma crops" active pharmaceutical ingredients produce.

Efforts have been made to produce proteins in animals and plants since the mid-1980s in order to obtain a higher yield than from previous sources. For example, sheep have been genetically engineered so that their milk contains a protein that helps blood clot, and bacteria have been genetically engineered to produce insulin . The proteins produced in this way are called “recombinant proteins”.

In principle, there are two ways of producing pharmaceutical plants:

The advantage over molecular pharming with animal cells is the distant relationship and thus the incompatibility of pathogens that can accumulate in the cultures. A purification step that may be omitted and the fact that plants only need light, air, water and nutrient salts to grow, also make the process cheaper. A scale-up is also easier than in cell cultures. Disadvantages are the lower efficiency in protein production and a different possibly incompatible glycosylation . In the future, pharmacologically active substances in edible parts of plants could enable vaccination through food.

Research, Development and Use

The Office for Technology Assessment at the German Bundestag (TAB) presented a study on "genetically modified plants of the second and third generation" on February 23, 2006. The subject of “pharmaceutical plants” was also included. This area is the most advanced in the world, according to the report. Numerous active ingredients produced in genetically modified plants are already in clinical trials.

Most of the genes built into pharmaceutical plants so far come from humans or animals, e.g. B. pigs, cattle, rabbits.

In most of the field trials carried out to date, the ability to produce pharmaceuticals has been built into food crops, e.g. B. corn , rice , soy , potato or barley .

Examples:

  • US scientists are already testing a dental caries antibody of plant origin on patients.
  • Avidin , a protein from chicken eggs, is already produced by genetically modified maize plants and used for medical laboratory diagnostics.
  • After a report from the GM Contamination Register on August 17, 2006, a US court ruled that the US Department of Agriculture violated applicable environmental law because between 2001 and 2003 it carried out experiments in Hawaii with genetically modified corn and sugar cane from ProdiGene, without an environmental impact assessment. Monsanto, Garst Seed and the Hawaii Agriculture Research Center to produce hormones, vaccines against AIDS and hepatitis B, and proteins for the treatment of various diseases.

To promote European research in this area, the so-called “ Pharma Planta Consortium ” was founded, an association of 39 institutions from eleven EU member states plus the South African science agency CSIR, funded by the EU with 12 million euros. The consortium's research subjects are pharmaceutical plants for the production of active ingredients against diabetes mellitus and rabies , AIDS and tuberculosis .

In Germany, the Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Molecular Farming Department, Aachen, is in charge of pharmaceutical plant research .

In 2006, the trial cultivation of pharmaceutical plants outdoors was approved for the first time in Germany. The University of Rostock had submitted a corresponding application . Scientists at the university have inserted genes from the cholera bacterium and from a virus that causes rabbit hemorrhagic disease (RHD) into two different potato lines. The aim is to produce vaccines against cholera and RHD. The trial cultivation will take place between May 2006 and October 2008 on a site in Groß Lüsewitz near Rostock . Munich-based Icon Genetics AG, which has been a subsidiary of Bayer Innovation GmbH, which belongs to Bayer AG since the beginning of 2006 , started up a pilot plant for the production of medically usable proteins in tobacco plants in June 2008 at its subsidiary Icon Genetics GmbH in Halle (Saale) for the production of clinical samples .

Benefits of pharmaceutical plants

According to proponents

  • Antibodies can be produced in plants about ten to a hundred times more cheaply than in animals. Because the high costs for rearing and stable keeping or for the special living conditions of bacteria were eliminated.
  • problems of previous pharmaceuticals can thereby possibly be eliminated, e.g. B. allergenic effects.
  • the production of pharmaceutically active substances in plants instead of animals increases human safety: "A sugar beet cannot transmit BSE."
  • By using pharmaceutical plants instead of animals to produce pharmaceuticals, fewer animals may have to be slaughtered if the product was previously obtained from animal organs.
  • Pharmaceutical plants such as B. fast-growing, robust tobacco and corn are to be grown in developing countries so that cheap drugs can be produced locally. The medically effective fruit straight from the field would be ideal, without going through expensive preparations from the pharmaceutical companies. However, the proteins would have to be absolutely pure and always be present in the same concentration in the plant in order to avoid unintentional overdosing.

Risks and controversial issues

However, the advantages outlined above are offset by risks. Some are also recognized by scientists working in research (see Handelsblatt report).

In the opinion of critics, pharmaceutical plants represent “ the greatest conceivable danger to be expected from genetically modified organisms, alongside terminator plants and genetically modified trees” ( Umweltinstitut München ).

The fact that the production of pharmaceutical plants should also take place outdoors in the future is particularly controversial. The reason for the outdoor cultivation is the lower production costs compared to bioreactors.

According to critics

  • however, it is not possible to maintain control over genetically modified plants in the field. During release trials in Nebraska (USA), transgenic corn kernels, which produce a vaccine against a viral disease in pigs, were found in a silo between soybeans. In the USA and Canada, therefore, stricter security requirements have already been issued. The company in question has now stopped growing in Nebraska.
  • outdoor cultivation involves the great risk that crops used for food production and thus the food chain are contaminated, especially if, as in the past, widespread food crops are genetically modified. An “outcrossing” of active pharmaceutical ingredients in food plants could have life-threatening health consequences for humans or animals that come into contact with these plants. The consequence could be, for example, unwanted rabies vaccinations.
  • microorganisms in the soil can change the recombinant protein. The protein must therefore be extracted from the plant after harvesting and laboriously cleaned, which puts the price advantage of outdoor cultivation into perspective.
  • there is a risk that the human body will regard the vegetable protein as a foreign body and reject it, since the sugar chains attached in pharmaceutical plants differ slightly from those in animal proteins.

Possible security measures

In principle, there are two approaches to largely separate genetically modified plants from the environment:

  • physical measures ( containment ), for example
    • Sealing off the existing soil with foils
    • Greenhouses
    • spatial separation of the fields
  • biological measures ( confinement ), for example
    • Use of crops not used in agriculture
    • self-pollinating plants (e.g. rice, flax),
    • sterile plants (e.g. through terminator genes )

Preventing the spread of transgenic plants or the transfer of their genetically engineered properties to others is only possible to a certain, relatively high level with these measures. The TAB report draws the conclusion: “According to the current state of science and technology, containment and confinement in transgenic crops cannot offer a system that allows crops of GMO and non-GMO varieties grown in the open to exist side by side without any influence. Which degree of influence is tolerated under which conditions remains a social decision. "

References and literature

  1. ^ Eva L. Decker and Ralf Reski (2008): Current achievements in the production of complex biopharmaceuticals with moss bioreactor . Bioprocess and Biosystems Engineering 31, 3-9.
  2. ↑ Frederike Bruhse, spectrum directly, Green drug factories , December 20 of 2010.
  3. ↑ GM Contamination Register ( GeneWatch UK and Greenpeace International): USA - Environmental rules broken in allowing trials with GM crops producing drugs , August 17, 2006.
  4. ↑ Philip Bethge: Pharmafabrik auf dem Acker , Spiegel online, May 29, 2006.
  5. ↑ Institute for Land Use of the Faculty of Agricultural and Environmental Sciences at the University of Rostock: Research project vaccines ( Memento from July 20, 2007 in the Internet Archive )
  • Corinna Döpke, Klaus Minol: Outcrossing barriers for pharmaceutical plants & Co. New safety concepts for genetically modified plants. In: teaching biology. , 29. 2005, 301, pp. 43-49, ISSN  0341-5260

Web links