Pharmacognosy with the Basics of Plant Biochemistry - Kovalyov V. M. 2004

General Part
Biotechnology of Medicinal Plants

Biotechnology is the industrial application of biological processes aimed at obtaining highly efficient microorganisms and Cell and tissue cultures with programmed properties. It belongs to rapidly developing interdisciplinary fields of scientific and technological progress—ranging from the long-established technology of in vitro cell and tissue culture to genetic biotechnology, or Introduction/32.html">Genetic Engineering. Biotechnology is quite heterogeneous, as it addresses a complex of problems and relies on elements from various sciences: microbiology, biochemistry, Cytology, pharmaceutical botany, as well as organic, inorganic, physical, and colloid chemistry, among others. The accumulation of BIOLOGICALLY ACTIVE SUBSTANCES is monitored using phytochemical Methods.

An important task of pharmacognosy is the search for new sources of biologically active substances and pharmaceutical substances. Global trends in the pharmaceutical industry indicate that using biotechnology to obtain plant raw Materials with a programmed chemical composition is promising and, in some cases, economically advantageous. Cell and tissue culture is advisable for producing metabolites of Medicinal plant raw materials that have a limited natural resource base. The advantage of this method is that the technological process is carried out within a limited timeframe, which saves resources on cultivating Medicinal Plants and preserves land areas. Standardized (homogeneous) plant substances are obtained under standard conditions of a controlled process, which limits the Influence of Environmental and stress factors on the yield of biologically active substances. The resulting biomass is environmentally friendly since no herbicides or pesticides are used, and the COMPOSITION OF THE nutrient medium is strictly regulated.

PLANT CELL CULTURE involves The stimulation of Cell Division in isolated plant segments. The first reports on the feasibility of growing pieces of plant tissue date back to 1893. Tissue culture of the medicinal plant Madagascar periwinkle (*Catharanthus roseus*) was first successfully obtained by P. White in 1945. He and R. Gautheret are considered the founders of plant Tissue and organ culture as a new branch of biological science. The possibility of growing plant Cells and Tissues on an industrial scale emerged in the late 1950s following the invention of specialized devices—fermenters—which allow for the supply of nutrient media, Water, and air, the maintenance of stable temperatures, pH regulation, and necessary agitation. This period also marks the beginning of The Development of this method in CIS countries. The establishment of ajmaline-producing strains from *Rauwolfia serpentina* stem tissue and reserpine-producing strains from ROOT tissue is associated with the names of R. G. Butenko and O. G. Volosovych. Significant success was also achieved in cultivating Madagascar periwinkle, smooth stephania (*Stephania glabra*), Indian thorn apple (*Datura innoxia*), Asian ginseng (*Panax ginseng*), and other plants.

Plant tissue culture is based on chaotic cell division, resulting in The formation of callus tissue. Callus represents an undifferentiated biomass that grows from an explant on an artificial nutrient medium under aseptic conditions. In nature, callus formation occurs as a response to plant injury, forming a protective growth (wound callus) at the site of damage, where immune mechanisms protect the plant from infection. During tissue culture cultivation, all plant cells become callus cells. Explants (segments of stems, leaves, roots, seedlings, seeds, etc.) are placed into a nutrient medium. Parenchymal cells undergo dedifferentiation, begin to divide, and form an undifferentiated biomass (callus). Callus tissue culture can be maintained for a long time by periodically dividing it into transplants.

Each individual isolated tissue culture possesses its own cytological, genetic, morphological, and biosynthetic characteristics; therefore, specialists thoroughly study each callus culture as a potential producer of biologically active substances.

The prerequisites for utilizing Higher Plant Cell and tissue culture in the biotechnological industry for the search of biologically active substances include:

their ability to produce metabolites traditionally used for drug development;

the possibility of synthesizing fundamentally new biochemical substances that surpass traditional ones in pharmacological activity;

the cellular transformation of inexpensive precursors into valuable final products.

Plant tissue cultures are grown primarily using two methods: surface culture and suspension culture. The surface method utilizes Agar-solidified nutrient media, thin gel layers, or liquid nutrient media. In the suspension method, callus tissue is continuously cultivated in a liquid nutrient medium.

An important factor in establishing an efficient biotechnological system is the Selection of a nutrient medium that meets the requirements of the tissue culture for chemical components necessary for the optimal Biosynthesis of the target product. Mandatory components of nutrient media include mixtures of mineral salts (macro- and microelements), phytohormones, and carbon sources.

The tissue culture method is gradually expanding in pharmaceutical manufacturing. Table 1 lists the biologically active substances obtained using this method.

Biologically active substances obtained via tissue culture

Table 1

It should be noted that, alongside its positive features, the tissue culture method also has certain drawbacks: it requires complex and expensive equipment such as controlled biotechnological reactors, yields a low quantity of biologically active substances, and is prone to cellular Aging and associated blockade or disruption of biosynthetic processes. Decisions regarding industrial Structure/175.html">Implementation are made by companies taking these factors into account, along with the demand for the substance on the global pharmaceutical market and overall economic feasibility.

Thus, while the potential of the biotechnological method of medicinal plant tissue culture is substantial, commercial raw material production must successfully compete with alternative systems for obtaining biologically active substances.