Mushrooms and their laboratory cultures as a source of therapeutic substances

Print Friendly Version of this pagePrint Get a PDF version of this webpagePDF

 

 

FACULTY OF PHARMACY

 

The number of new studies on therapeutic and nutritive substances present in fungi is increasing year by year. As a result of such wide interest, new scientific journals have emerged, e.g., International Journal of Medicinal Mushrooms and Mycoscience, along with numerous research projects. One such project is being carried out by scientists from the Department of Pharmaceutical Botany.

Mushrooms play a significant role both in nature and in the human economy. For example, they make the existence of forests possible, as they transform dead matter into water-soluble inorganic compounds that are accessible for plants. This decomposition is an aerobic process, which is proven by such things as the characteristic smell of forest litter. It is worth noting that mushrooms transform enormous amounts of biomass, regenerating the natural environment without producing waste. Recently, Fungi have been assigned to a separate kingdom in taxonomy and mycology – the area of biology devoted to them – is an innovative discipline of science.

Therapeutic value

Due to the increasing consumption of mushrooms, both wild and cultivated ones, the need has arisen to analyze the substances contained in them that determine the proper functioning of the human body. The opinion that mushrooms are hard to digest and their consumption may lead to poisoning prevails in the media, although mushrooms are praised for their taste and aroma. Obviously, to be able to safely enjoy the taste of edible species, we should pick only those mushrooms we know well or those that originate from commercial farms.

The nutritive and therapeutic value of cultivated mushrooms legally sold in Poland (including champignons, oyster mushrooms, scaly lentinus and jelly-ear) does not differ from that of wildly growing ones. Numerous studies have proven that the structure of the composition of free and bound amino acids contained in mushrooms is similar to that of animal proteins. Other groups of substances that have been subject to detailed analysis are numerous phenolic and terpenic compounds, vitamins or bioelements with an anti-oxidating effect. Biologically and therapeutically active elements of mushrooms are used in the therapy of various civilization illnesses, i.e., of cardiovascular diseases, diabetes, atherosclerosis and cancer. As complex carbohydrates originating from mushrooms have been used in oncological therapy for the longest time, they are considered the best known ingredients of mushrooms, in comparison to other compounds.


Bay bolete. Photo: J.A. Bossowski

Valuable indoles

A group of compounds still only known to a very limited extent are non-hallucinogenic indoles. They have been analyzed in detail at the Department of Pharmaceutical Botany. Previous research related to the existence of indole compounds in mushrooms focused mainly on tryptophan – an amino acid necessary for the proper functioning of the body, obtained from diet and constituting a precursor for the synthesis of all indole compounds in the human organism. Considering the importance of the indole derivatives (tryptophan, serotonin, melatonin or tryptamine) which are hormones or their precursors, it became necessary to determine their content in edible mushrooms. The following species were analyzed: Penny bun (Boletus edulis), the parasol mushroom (Macrolepiota procera) and the Yellow knight (Tricholoma equestre), and others. Additionally, the research also covered the pilei of edible mushrooms from commercial farms: Champignon Agaricus bisporus, the jelly-ear, scaly lentinus and oyster mushroom.

The obtained results prove that typical edible species contain important indole compounds that act as exogenous amino acids and hormones of the nervous system. However, as most mushrooms are subject to thermal processing before consumption and due to the sensitivity of indole compounds to temperature, research was also conducted on cooked mushrooms. Scientists from Kraków have proven that thermal processing of edible mushrooms influences the content of indole compounds. On average, a twofold decrease of the total content of indole compounds was noted in cooked mushrooms, although they still contain significant amounts of tryptophan or serotonin.

Phenolic compounds and tree mushrooms

Other directions of the conducted research focus on the analysis of phenolic compounds in edible mushrooms; in particular, of the predominant phenolic acids. It is precisely their strong anti-oxidant effect and the ability to protect against oxidation-related damage of vital structures (cellular membranes, structural proteins, enzymes, lipids or nucleic acids) that contributes to their broad spectrum of activity. The presence of phenolic acids was confirmed in the analyzed edible mushrooms. Species characterized by the highest diversity of phenolic compounds were: bay bolete (Boletus badius), golden chanterelle and oyster mushroom.

Numerous studies carried out throughout the world point to the high therapeutic activity of extracts and compounds obtained from tree mushrooms, commonly referred to as bracket fungi. Experimental studies have confirmed their therapeutic activity. Some of the studies concern the analysis of extracts from bracket fungi aimed at the search of antioxidants, with a dominant group of phenolic acids. In this context, local species of these fungi were also analyzed.

Based on the analysis of the content of phenolic acids in the extracts from the discussed bracket fungi, the presence of numerous phenolic acids was confirmed. The total content of phenolic acids in individual species was determined and their high antioxidant effect was confirmed, which in turn guarantees anti-cancer and anti-aging activity. All this confirms that we should focus more on these species. It is worth mentioning that they are increasingly used in the production of pharmaceutical products or cosmetics.

Mycelial cultures

The difficulties in obtaining research material resulting from the temporary and often unpredictable occurrence of wild growing mushrooms was the reason why scientists created conditions for the development of mycelium growing in the laboratory. Laboratory culture also facilitates control over the absorption of nutrients by fungi. These cultures are maintained for Champignon Agaricus bisporus, golden chanterelle and bay bolete, among others.

The aim of the studies is to develop the best cultivation conditions for the growth of mushrooms, which gather large amounts of compounds of salutogenic properties. The scope of analyses includes studies on the creation of optimum conditions for mycelium growth by means of selecting a proper combination of chemical and physical factors. Indole compounds that are important for the human body were found in extracts obtained from cultured material, similarly as in the case of wild growing and cultivated mushrooms. Laboratory cultures of edible mushrooms are currently also used in research on the absorption and collection of selected indole compounds and bioelements. The objective of this activity is to obtain mycelium with a higher content of tryptophan and zinc, which might become a diet supplement.

Obtaining mushrooms that are richer in selected bioelements (zinc, magnesium, iron, copper) is particularly important in the phase of composing new, easily assimilated diet supplements. Cultivating them will be the next research objective of the scientists from the Department of Pharmaceutical Botany, which will be realized in co-operation with the AGH University of Science and Technology in Kraków.


Research team: Bożena Muszyńska, PhD; Katarzyna Sułkowska-Ziaja, PhD