Comments on the mechanisms of action of radiation protective agents: basis components and their polyvalence

Abstract

PurposeThese comments suggest a division of radiation protective agents on the grounds of their mechanism of action that increase the radio resistance of an organism.ConclusionGiven below is the division of radiation protective agents on the basis of their mechanism of action into 3 groups: 1) Radiation protective agents, with the implementation of radiation protective action taking place at the cellular level in the course of rapidly proceeding radiation-chemical reactions. At the same time, when the ionizing radiation energy is absorbed, these agents partially neutralize the “oxygen effect” as a radiobiological phenomenon, especially in the radiolysis of DNA; 2) Radiation protective agents that exert their effect at the system level by accelerating the post-radiation recovery of radiosensitive tissues through activation of a number of pro-inflammatory signaling pathways and an increase in the secretion of hematopoietic growth factors, including their use as mitigators in the early period after irradiation prior to the clinical development of acute radiation syndrome (ARS). 3) Radiomodulators including drugs and nutritional supplements that can elevate the resistance of the organism to adverse environmental factors, including exposure to ionization by means of modulating the gene expression through a hormetic effect of small doses of stressors and a “substrate” maintenance of adaptive changes, resulting in an increased antioxidant protection of the organism. Radiation protective agents having polyvalence in implementation of their action may simultaneously induce radioprotective effect by various routes with a prevalence of basis mechanisms of the action.

Research and Development of Radioprotective Agents: A Mini-Review

“…As an example, hypoxia is an important mechanism for tumor radioresistance in hypofractionated radiotherapy, which must be considered in the treatment planning process [112] , while an agent that could temporarily create hypoxic condition in the normal tissue may have radioprotective effect [113] .…”

Radioprotective and radiomitigative effects of BP-C2, a novel lignin-derived polyphenolic composition with ammonium molybdate, in two mouse strains exposed to total body irradiation

“…Also, on day 8 after irradiation, BP-C2, administered to C57BL/6 mice 24 h after 7.0 Gy of irradiation, improved animal survival by 40% and mean survival time (MST) by 1.5 days. This type of pattern is common for radiomitigators, which in general have a low DRF and are efficient mostly in the mid-lethal range of radiation doses (Vasin 2014;Singh et al 2014a;Rosen et al 2014). Such agents exert a systemic effect, accelerating recovery of radiosensitive tissues after exposure to radiation.…”

“…Thus, there remains an unmet medical need for radioprotective and mitigative agents. Phenolic compounds (rosmarinic acid (Xu et al 2016), lycopene (Gajowik and Dobrzynska 2014) and flavonoids (Grebeniuk et al 2013;Vasin 2014)) are reported to exert radioprotective effects through various mechanisms. BP-C2 is a novel lignin-derived polyphenolic composition with ammonium molybdate.…”

Correntes de Blocos: Algoritmos de Consenso e Implementação na Plataforma Hyperledger Fabric

“…O gasto energético do consenso por prova de trabalho é ecologicamente inaceitável. Outros algoritmos baseados em prova procuram mitigar o excesso de gasto energético e as limitações de desempenho presentes na prova de trabalho [Vasin 2014, Schwartz et al 2014, Kiayias et al 2017. Uma breve explicação dos algoritmos mais conhecidos é mostrada a seguir:…”