RUDN University biologist found that Chinese date improves the immune system of fish
In fisheries, antibiotics are usually used to prevent infections. However, their use leads to the emergence of strains of bacteria resistant to them. This is a potential threat not only to fish but also to humans – in case that antibiotic-resistant bacteria begin to be transmitted from person to person. Researchers are looking for alternative drugs suitable for use in ichthyology.
Morteza Yousefi, a biologist from the RUDN University, and his colleagues investigated the properties of Zizyphus (Zizyphus jujube), known as "Chinese date" and found that it can be used as an antimicrobial agent for fish.
Morteza Yousefi tested the immunostimulatory properties of this plant on carp (Cyprinus carpio). The biologists gave the fish a solution of ethanol and distilled water with Ziziphus fruit juice with a concentration of 0.25%, 0.5%, and 1%. Then they took samples from the fish mucosa and monitored how immune parameters change: the number of antibodies, the activity of enzymes – proteases and the expression of genes of signaling molecules – cytokines, which, in particular, trigger phagocytosis, that is, the destruction of bacteria.
Analysis of the data showed that carp, which were given a solution of the fetus with a concentration of 0.5%, increased the number of antibodies. The more antibodies in the blood, the more extraneous compounds – antigens – they can "catch".
Besides, ichthyologists have found a connection between the extract of dates in the diet of fish and the presence of cytokines. The experiment showed that the concentration of the solution is 0.25% does not change the immune reactions of carp, but 0.5% and 1% solution increases the expression of cytokine genes and the activity of protease enzymes that are involved in the "digestion" of killed pathogenic bacteria and in triggering the processes of extraneous cells death (apoptosis).
The results are published in the journal Fish and Shellfish Immunology.
RUDN University chemist proposed a new method to create catalysts on a porous silicon matrix with metal nanoparticles. Efficient catalysts for organic reactions are obtained, for example, for the synthesis of vanillin, which is in demand in the food and perfume industry.
When talking about COVID-19, television, newspapers, magazines, and social media turn to battle metaphors that make the fight against the pandemic feel like a war. Also, the coronavirus is often discussed in an excessively alarming and threatening tone. This problem is so acute that there is even the term for that — infodemia. It describes the panic in the media and social networks. A linguist of RUDN University studied how such a language affects the notions of people regarding COVID-19.
Ecologists of the RUDN University showed that one of the methods used to detect the soil organic matter turns out to be ineffective after precipitation. Studies have shown that the impact of rain on the surface of arable soils leads to a decrease in the accuracy of modelling of organic matter content by 70%. The ecologists also suggested the way to compensate for this negative phenomenon and increase the accuracy of calculations to 84%.