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Raspberries contain high levels of antioxidants, which help protect the human body against many diseases, including cancer. Research by Bartosz Fotschki, PhD, from the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn, has shown that in order to boost the pro-health effect of antioxidants from raspberries, combining them with prebiotics is recommended.

– Appropriate stimulation of intestinal bacteria, through prebiotic supplementation, increases the efficiency of the breakdown of raspberry polyphenols into chemical compounds with greater pro-health potential, e.g. with a beneficial effect on fat metabolism in the liver – emphasises study author Bartosz Fotschki, PhD, from the Department of Biological Function of Food of the IARFR PAS in Olsztyn.

A FEW WORDS ABOUT RASPBERRIES

Raspberries are one of the most popular fruit. They owe their success not only to their sweet, juicy taste, but also to their well-known pro-health properties.

As Bartosz Fotschki reminds us, these fruits are a rich source of bioactive compounds with strong pro-health potential, e.g. characterised by a high content of antioxidants, mainly phenolic compounds, e.g. cyanidins, anthocyanins, elagotannins and phenolic acids. Antioxidants are natural substances that can help protect the human body against the development of many diet-related diseases.

– In addition to their strong antioxidant properties, the polyphenolic compounds found in raspberries also exhibit other beneficial biological activities, including regulating inflammation, lipid metabolism, bile acid synthesis in the liver and the activity of the microbiota in the gastrointestinal tract – indicates the scientist, who is involved in exploring the pro-health properties of biologically active compounds towards the prevention and alleviation of diet-induced metabolic disorders (e.g. obesity, non-alcoholic fatty liver disease).

BOOST THE EFFECT

The pro-health effects of raspberries can be further enhanced, which is why Bartosz Fotschki examined how to influence the gastrointestinal bacteria to do more intensive 'work’ in breaking down the polyphenols from raspberries.

In his research, the scientist relied on the combination of a raspberry polyphenol preparation with the prebiotic effect of fructooligosaccharides (these are fibre products that support the growth of probiotic bacteria, which are essential for proper intestinal function).

– The results of the study confirmed an enhancement in the efficiency of metabolising polyphenols to chemical compounds with greater pro-health potential. The mechanism of action of this mixture combines an increase in the number of bacteria showing the ability to metabolise polyphenols in the gastrointestinal tract with an increased concentration of metabolites that reach the liver and regulate mechanisms related to lipid metabolism, oxidative stress and inflammation – the scientist points out.

The results of the research have been published in one of the leading journals in the discipline of food technology and nutrition: Food Research International.

In other words – by combining the consumption of raspberries with a prebiotic supplement, we boost the pro-health effects of the fruit, and this has a beneficial effect on liver metabolism, among other things.

– Further human studies are still needed, but the combination of polyphenols found in various products (e.g. juice, mousse, freeze-dried) with fructooligosaccharides could be a valuable dietary supplement to support health prevention and could already appear in many products with pro-health potential – concludes Dr. Fotschki.

The study was carried out as part of the project 'Raspberry polyphenols and their metabolites as regulatory factors in the mechanisms of non-alcoholic fatty liver disease’ (UMO-2018/31/D/NZ9/02196), funded by the National Science Centre.

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Scientists at the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn are investigating the mechanism of long-term infection of the fetus with cytomegalovirus. The virus is usually harmless for healthy people. The problem arises in immunocompromised patients and pregnant women, as it crosses the placenta and can cause serious congenital diseases.

– We are investigating the molecular basis for establishing long-term cytomegalovirus infection in neural cells. We hope to find out the factors responsible for the persistence of the virus in neural cells, and thus identify the causes of the observed damage to the nervous system associated with cytomegalovirus-induced congenital disease – emphasises Dr Magdalena Weidner-Glunde, leader of the research project and head of the Molecular Microbiology and Virology Laboratory of the IARFR PAS in Olsztyn.

THE DORMANT VIRUS

Human cytomegalovirus (HCMV) infection is very common, with more than 80 % of the Polish population infected. The primary infection in healthy people is usually asymptomatic or shows the symptoms of a slight cold, but in immunocompromised patients, e.g. after transplantation (when immunity is deliberately lowered to prevent transplant rejection) or those with AIDS, it can cause serious illness.

– HCMV is also a cause of congenital disease, as the virus is able to pass from the bloodstream of the infected mother through the placenta to the fetus. The disease resulting from congenital cytomegalovirus infection is associated with infection of the central nervous system and consequent sensory-nervous damage. Symptoms associated with HCMV congenital disease can include hearing loss, visual impairment or even intellectual disability, explains the researcher.

The herpesviruses (such as herpes virus and chickenpox virus), once they enter our body, remain in our body for the rest of our lives. The response of our immune system to their presence – i.e.  antibodies – can be detected by laboratory blood tests. They also allow us to determine whether a person has an active or latent infection.

In fact, the life cycle of herpesviruses comprises two phases: a latent (dormant) phase, from which the virus occasionally 'wakes up’ to enter the active (lytic) phase. – In the lytic phase, the virus actively multiplies by producing a large number of new viral particles. In contrast, in latency, viral protein synthesis is reduced to a minimum and there is no production of new viral particles, which prevents our immune system from effectively detecting the infection – explains Magdalena Weidner-Glunde.

HCMV has a circular genome (episome) that, during latent infection, has the ability to attach to host chromosomes and thus ensure the persistence of infection. – In other herpesviruses, it is known which protein is responsible for this binding of the viral genome to chromosomes. In the case of cytomegalovirus, we do not yet know this. In our research, we are investigating whether the viral protein IE1 is involved in the binding of the genome to the chromosomes and thus – determines the survival of the virus. Analysing the function of this protein will allow us to learn and understand how it is possible for the cytomegalovirus genome to survive in the cell for such a long time – points out Magdalena Weidner-Glunde.

LEARN THE DIFFERENCES IN CELL TYPES

Cytomegalovirus particles have different properties in terms of infection and multiplication in different cell types. So far, cytomegalovirus has been studied in its latent phase mainly in haematopoietic stem cells (from which, for example, red blood cells can arise). Recently, it has been shown that long-term HCMV infection can also take place in neural precursor cells (from which, for example, neurons are later formed). Long-term infection in these cells may be responsible for the sensory-neural damage that is symptomatic of HCMV-induced congenital disease.

Scientists from Olsztyn are also looking into comparing the mechanism of long-term virus infection in the two cell types in order to understand the differences and how cytomegalovirus disrupts the functioning of different cell types.

– For the active phase of virus infection, drugs are given to inhibit viral replication. However, there are still no drugs for the latent phase to help simply get rid of it. The results of our study will therefore be able to contribute not only to the understanding of the pathogenesis of congenital cytomegalovirus infections, but also to help develop new therapies – concludes the scientist. The research – led by Magdalena Weidner-Glunde, PhD – is being conducted as part of a project entitled “Exploring mechanisms of congenital human cytomegalovirus infection: replication, spread and latency establishment”, funded by more than PLN 3 million from the National Science Centre. The project is expected to end in May 2024.

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