Hepatic Gene Expression Changes in Rats Internally Exposed to Radioactive 56MnO2 Particles at Low Doses

Lactiplantibacillus plantarum and Saussurea costus as Therapeutic Agents against a Diabetic Rat Model-Approaches to Investigate Pharmacophore Modeling of Human IkB Kinase and Molecular Interaction with Dehydrocostus Lactone of Saussurea costus

Lactic acid bacteria is well-known as a vital strategy to alleviate or prevent diabetes. Similarly, the plant Saussurea costus (Falc) Lipsch is a preventive power against diabetes. Here, we aimed to determine whether lactic acid bacteria or Saussurea costus is more effective in treating a diabetic rat model in a comparative study manner. An in vivo experiment was conducted to test the therapeutic activity of Lactiplantibacillus plantarum (MW719476.1) and S. costus plants against an alloxan-induced diabetic rat model. Molecular, biochemical, and histological analyses were investigated to evaluate the therapeutic characteristics of different treatments. The high dose of S. costus revealed the best downregulated expression for the IKBKB, IKBKG, NfkB1, IL-17A, IL-6, IL-17F, IL-1β, TNF-α, TRAF6, and MAPK genes compared to Lactiplantibacillus plantarum and the control groups. The downregulation of IKBKB by S. costus could be attributed to dehydrocostus lactone as an active compound with proposed antidiabetic activity. So, we performed another pharmacophore modeling analysis to test the possible interaction between human IkB kinase beta protein and dehydrocostus lactone as an antidiabetic drug. Molecular docking and MD simulation data confirmed the interaction between human IkB kinase beta protein and dehydrocostus lactone as a possible drug. The target genes are important in regulating type 2 diabetes mellitus signaling, lipid and atherosclerosis signaling, NF-κB signaling, and IL-17 signaling pathways. In conclusion, the S. costus plant could be a promising source of novel therapeutic agents for treating diabetes and its complications. Dehydrocostus lactone caused the ameliorative effect of S. costus by its interaction with human IkB kinase beta protein. Further, future studies could be conducted to find the clinical efficacy of dehydrocostus lactone.

External dose estimates of laboratory rats and mice during exposure to dispersed neutron-activated 56Mn powder

Estimates of external absorbed dose in experimental animals exposed to sprayed neutron-activated 56Mn powder are necessary for comparison with internal absorbed doses estimated under the same exposure conditions, which is required for a correct interpretation of the observed biological effects. It has been established that the measured dose of external absorbed dose as a result of gamma irradiation range 1-15 mGy, which is order of magnitude less than the maximal dose of internal gamma and beta irradiation of the whole body of the same experimental animals irradiated under the same conditions: according to the available literature data, the maximal values ​​of absorbed dose of internal gamma-beta irradiation of the whole body are in the range of 330 mGy-1200 mGy for mice and 100 mGy-150 mGy for rats. It is concluded that under the conditions of experiments with dispersed neutron-activated powder 56MnO2, internal gamma-beta irradiation of experimental animals is the main factor of radiation exposure compared to external gamma irradiation.

Overview and analysis of internal radiation dose estimates in experimental animals in a framework of international studies of the sprayed neutron-induced 56Mn radioactive microparticles effects

The aim of overview is to present the pooled data of published internal dose estimates and the results of corresponding analysis of internal irradiation features of experimental mice and rats after exposure to sprayed neutron activated radioactive 56MnO2. These dose estimates were conducted in a framework of multicenter international study to investigate biological effects as a result of exposure to sprayed radioactive 56MnO2 microparticles. Radionuclide 56Mn (T1/2 = 2.58 h) is one of the main gamma-beta emitters during the first hours after neutron activation of soil following nuclear explosion. It was concluded that there are three groups of organs of mice and rats, the radiation doses of which differ by approximately an order of magnitude: the group with the highest radiation doses (large and small intestine, stomach, skin and lungs), the group with lowered radiation doses (eyes, esophagus, trachea), the group with the lowest radiation doses (liver, heart, kidneys). The radiation doses to organs are proportional to the activity of the sprayed radioactive powder. The distribution of internal radiation doses among organs of experimental mice of different strains but of the same age was practically the same in case of exposure to the same activity of sprayed 56MnO2 powder. Doses of internal irradiation of experimental mice substantially exceed the doses of internal irradiation of experimental rats exposed to the same activities of the sprayed 56MnO2 powder. The data presented in the overview can be helpful for further investigation and for interpretation of the biological effects of this type of irradiation.

The overview of neutron-induced 56Mn radioactive microparticle effects in experimental animals and related studies

Investigation into the risks associated with radiation exposure has been carried out on those exposed to radiation in Hiroshima and Nagasaki, Semipalatinsk and other parts of the world. These risks are used as a guidance standard for the protection for radiation workers and the general public when exposed to radiation, and it sets upper regulatory limits for the amount of radiation exposure. However, the effects of internal exposure to radioactive microparticles have not been considered in these studies. These effects cannot be ignored since the exposure dose increases are inversely proportional to the square of the distance to the vicinity of the particles and can exceed tens of thousands of mGy. So far, only retrospective studies of people who have been exposed to radiation have been conducted, therefore we hypothesized that animal experiments would be necessary to investigate these effects. As a result, we found specific effects of radioactive microparticles. One particularly noteworthy finding was that internal exposure to radioactive microparticles resulted in pathological changes that were more than 20 times greater than those caused by the same level of external exposure. In contrast, there were other results that showed no such effects, and the reasons for this discrepancy need to be clarified. We also conducted RNA expression experiments and found that there was a difference between external exposure to 60Co gamma rays and internal exposure to 56Mn microparticles. In the future, we will need to study the mechanisms behind these findings. If the mechanism can be confirmed, it is expected to lead to the development of protective and therapeutic methods.