A healing polymer derived from oats could aid in combating the effects of radiation exposure.

The cell walls of plants are incredibly strong due to two polymers—cellulose and lignin. Lignin, in addition to its mechanical function, also enhances the resilience of plants against adverse environmental conditions, such as exposure to chemicals and parasites. These protective functions are attributed to the compound's antioxidant, antifungal, and antibacterial properties. Scientists believe that the beneficial properties of lignin could be utilized for medical purposes if the appropriate compound is introduced into the human body. However, the effects of lignin on animals and humans have remained insufficiently studied, making it impossible to draw conclusions about its safety and efficacy.

Researchers from the Federal Research Center "Komi Science Center of the Ural Branch of the Russian Academy of Sciences" (Syktyvkar) investigated the safety and biological activity of lignin derived from the stems of oats Avena sativa. This plant was chosen because the lignin obtained from it contains a high amount of phenolic groups, which determine the antioxidant effect.

Biologists chemically extracted lignin from oat stems and dissolved it in water using an original method. First, the researchers demonstrated the absence of toxic effects of this preparation on human cell cultures. Then, they checked whether the preparation had any toxic effects on laboratory mice. For this, a solution of lignin was introduced into the abdominal cavity of 20 animals in four different concentrations (with five mice in each experimental group). An additional five rodents were used as a control group—they received a saline solution instead of lignin.

The experiment showed that the preparation did not lead to any deterioration in the condition of the animals. Moreover, it initiated processes for the destruction of cells with damaged DNA in the bone marrow and thyroid gland, thereby protecting these organs from the accumulation of defects.

Additionally, the authors examined the effects of long-term lignin administration in mice. For this, the rodents were given a solution of the polymer daily for a period of 1 to 8 months. At the end of this period, biologists investigated the state of their internal organs.

The experiments revealed that the weight of the animals receiving lignin, as well as the mass and appearance of their internal organs, did not differ from the control group. Thus, no negative effects of the preparation were observed. Conversely, lignin had a pronounced positive effect on the reproductive organs of the rodents. For instance, in males, the prolonged administration of the preparation increased the production of sex cells by 30% and reduced the number of "defective" sperm by 35%. In females, lignin extended the favorable conception stage of the cycle by 15%, thereby increasing fertility.

The authors also conducted tests on the cognitive abilities of the mice from the experimental and control groups, monitoring the behavior of the rodents in a round open space. Observations showed that lignin stimulates exploratory behavior in animals and reduces anxiety.

"During the experiments, we confirmed that lignin from oats does not have a toxic effect on rodents. This indicates that the polymer could potentially serve as a basis for biomedical preparations. We determined that lignin prevents the accumulation of cells with damaged DNA in rapidly dividing tissues—such as the bone marrow and gonads. Therefore, our research will be an important step for future work to identify the radioprotective properties of natural lignins. In the future, we plan to study and test other lignins extracted from woody and herbaceous medicinal plants in experiments on laboratory animals, thereby expanding the range of biomedical preparations," says project leader Lyudmila Kocheva, Doctor of Chemical Sciences and Leading Researcher at the Komi Science Center of the Ural Branch of the Russian Academy of Sciences, supported by a grant from the Russian Science Foundation.

Previously, researchers obtained a nanomaterial from a common weed in Russia—the Sosnowsky's hogweed—that is capable of removing radionuclides from water. This development can be used for the purification of wastewater from radiation-hazardous enterprises.