Green tea gave scientists a new tool for gene therapy

SL, Четверг 20 Сентябрь 2018 - 18:58:10

Green tea is known to possess many beneficial effects, for example, saves from insomnia, promotes the formation of new brain cells, improves memory, reduces the risk of cancer and protects against cardiovascular diseases.

Studying the properties of various compounds found in green tea, researchers from the American chemical society found that an antioxidant called epigallocatechin gallate (EGCG) has beneficial effects on cells.

Experimenting with the connection, the researchers suggested that it can be used for medicinal purposes, in particular for delivery into cells of particular RNA molecules.

We are talking about small interfering RNAS (siRNAs). These double-stranded molecules, despite the epithet "small", we have a huge therapeutic potential, explain the experts. The fact that siRNA can suppress the expression of genes associated with the development of the disease.

Getting into the cells, the molecules act on other RNA (located inside cells) and affect the production of proteins encoded by various genes. This mechanism is called RNA interference, and its discoverers in 2006 he was awarded the Nobel prize in physiology and medicine.

Using RNAi, it is possible to destroy "solid" cancer, reduce cholesterol in the blood, or to protect the plant from pathogens.

But the main difficulty was the method of delivery of siRNA to the desired location, the researchers recognized. Small and negatively charged molecules is not so easy to cross the cell membrane, also, in their way can meet the enzymes that destroy RNA.

To protect the "spies", scientists tried to cover their various polymers. However, low molecular weight variants could only protect siRNA from damage, but does not solve the question of their delivery to the cells and high molecular weight polymers could prove to be too toxic and do more harm than good.

Then, the team led by Jun Cheng (Cheng Yiyun) from East China normal University decided to appeal to the EGCG.

Experts have established that the compound forms a strong bond with the RNA molecules, and if you cover these "allies" of the low molecular weight polymer, nanoparticles are obtained which will retain the siRNA in security and delivered to the right cells.

In the course of work, the researchers first combined the interfering RNA and EGCG, which "self-organized" in a negatively charged nucleus. Then it was covered with a shell of the positive charged polymer.

According to scientists, the resulting nanoparticles effectively shut down several of target genes in cultures of specially grown cells. The experiments also showed that overcoming the cell membrane is no longer a problem for RNA-interference.

Then the team tested their invention on mice of siRNA targeting on Pro-inflammatory enzyme in the intestinal cells. As a result of therapy in rodents decreased inflammation, they stopped losing weight and the contractions of the colon slowed down.

The big plus is the fact that EGCG enhances the therapeutic effect of the nanoparticles due to its antioxidant and anti-inflammatory properties, experts added.

Scientific work on the results of this study are published in the journal ACS Central Science.

By the way, the authors of the project "Conduct.Science" (nauka.vesti.ru) reported that in the United States approved the first of its kind therapy based on RNA interference.




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