Assessment of the Acute Toxicity of Chlorophyllin and Trolox for the Possibility of Studying Their Radioprotective Properties.

The acute toxicity of chlorophyllin and trolox upon intraperitoneal injection of their solutions was studied in male ICR (CD-1) mice. The LD50 of chlorophyllin was found to be 633±37.2 µg/g body weight, which is lower than the LD50 of established radioprotectors. Trolox is technically non-toxic under the conditions of our study. The results obtained highlight the need for a detailed study of the radioprotective properties of trolox and chlorophyllin.

Radioprotective Properties of Riboxin (Inosine) and Indralin under External Irradiation.

A comparative assessment of radioprotective properties of inosine nucleoside (riboxin) and recognized radioprotector indralin was carried out. We analyzed survival of male ICR CD-1 mice weighting 32.2±0.2 g exposed to external X-ray radiation at doses 6.5 and 6.75 Gy and receiving indralin at a dose of 100 or 150 µg/g body weight or riboxin (inosine) at a dose of 100 or 200 µg/g body weight before irradiation. The survival analysis was carried out by the Kaplan-Meier method. The significance was assessed by using the log-rank-test. Inosine showed a significant difference from the irradiated control only at a dose of 100 µg/g body weight at a radiation dose of 6.75 Gy. The survival of animals treated with indralin was significantly higher in comparison with not only the irradiated control group, but also with the groups receiving inosine.

Chemiluminescence Detection in the Study of Free-Radical Reactions. Part 2. Luminescent Additives That Increase the Chemiluminescence Quantum Yield.

The present review examines the use of chemiluminescence detection to evaluate the course of free radical reactions in biological model systems. The application of the method is analyzed by using luminescent additives that enhance the luminescence thanks to a triplet-singlet transfer of the electron excitation energy from radical reaction products and its emission in the form of light with a high quantum yield; these additives are called chemiluminescence enhancers or activators. Examples of these substances are provided; differences between the so-called chemical and physical enhancers are described; coumarin derivatives, as the most promising chemiluminescence enhancers for studying lipid peroxidation, are considered in detail. The main problems related to the use of coumarin derivatives are defined, and possible ways of solving these problems are presented. Intrinsic chemiluminescence and the mechanism of luminescence accompanying biomolecule peroxidation are discussed in the first part of the review.

Chemiluminescence Detection in the Study of Free-Radical Reactions. Part 1.

The present review, consisting of two parts, considers the application of the chemiluminescence detection method in evaluating free radical reactions in biological model systems. The first part presents a classification of experimental biological model systems. Evidence favoring the use of chemiluminescence detection in the study of free radical reactions, along with similar methods of registering electromagnetic radiation as electron paramagnetic resonance, spectrophotometry, detection of infrared radiation (IR spectrometry), and chemical methods for assessing the end products of free radical reactions, is shown. Chemiluminescence accompanying free radical reactions involving lipids has been the extensively studied reaction. These reactions are one of the key causes of cell death by either apoptosis (activation of the cytochrome c complex with cardiolipin) or ferroptosis (induced by free ferrous ions). The concept of chemiluminescence quantum yield is also discussed in this article. The second part, which is to be published in the next issue, analyzes the application of chemiluminescence detection using luminescent additives that are called activators, a.k.a. chemiluminescence enhancers, and enhance the emission through the triplet-singlet transfer of electron excitation energy from radical reaction products, followed by light emission with a high quantum yield.