Radioprotective Role of Vitamins C and E against the Gamma Ray-Induced Damage to the Chemical Structure of Bovine Serum Albumin

3,5-Dihydroxy-4-methoxybenzyl alcohol, a novel antioxidant isolated from oyster meat, inhibits the hypothalamus-pituitary-adrenal axis to regulate the stress response

BACKGROUND

Antioxidants that can scavenge reactive oxygen in the brain and inhibit hyperactivity of the HPA axis are desirable.

AIMS

We investigated the cerebral translocation of the antioxidant 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA) and the effects of DHMBA administration on the hypothalamus-pituitary-adrenal (HPA) axis in stress-loaded rats.

METHODS

Experiment 1: Plasma and brain DHMBA concentrations were measured over time after oral DHMBA administration to male B6 mice. Experiment 2: Female Wistar Imamichi rats were used. The normal group was not subjected to stress. The stress, DHMBA, and vitamin E groups were subjected to individual and overcrowding stress. Brain and hippocampal 8-hydroxy-2'-deoxyguanosine levels, hippocampal glucocorticoid receptor-α levels, plasma corticosterone levels and RNA levels of glutathione peroxidase 4, catalase, and glutathione reductase in the hippocampus were measured.

RESULTS

In Experiment 1, DHMBA was not detected in the plasma or brain before DHMBA administration but was detected in both after administration. In Experiment 2, brain and hippocampal 8-hydroxy-2'-deoxyguanosine levels and plasma corticosterone levels were significantly lower in the DHMBA than in the stress group. Glucocorticoid receptor-α levels were higher in the DHMBA than in the stress group. DHMBA increased RNA levels of antioxidant enzymes in the hippocampus.

CONCLUSION

DHMBA was translocated to the brain after administration. DHMBA administration decreased 8-hydroxy-2'-deoxyguanosine levels in the brain and hippocampus, increased hippocampal glucocorticoid receptor-α levels, and decreased the plasma corticosterone concentration, suggesting that DHMBA inhibits hyperactivity of the HPA axis. Nrf2 pathway activity induced by DHMBA resulted in increased antioxidant enzyme levels in the hippocampus.

Targeting Oxidative Stress: The Potential of Vitamin C in Protecting against Liver Damage after Electron Beam Therapy

Background: Radiation-induced liver disease (RILD) is a severe complication arising from radiotherapy, particularly when treating abdominal malignancies such as hepatocellular carcinoma. The liver's critical role in systemic metabolism and its proximity to other abdominal organs make it highly susceptible to radiation-induced damage. This vulnerability significantly limits the maximum safe therapeutic dose of radiation, thereby constraining the overall efficacy of radiotherapy. Among the various modalities, electron beam therapy has gained attention due to its ability to precisely target tumors while minimizing exposure to surrounding healthy tissues. However, despite its advantages, the long-term impacts of electron beam exposure on liver tissue remain inadequately understood, particularly concerning chronic injury and fibrosis driven by sustained oxidative stress. Objectives: to investigate the molecular and cellular mechanisms underlying the radioprotective effects of vitamin C in a model of radiation-induced liver disease. Methods: Male Wistar rats (n = 120) were randomly assigned to four groups: control, fractionated local electron irradiation (30 Gy), pre-treatment with vitamin C before irradiation, and vitamin C alone. The study evaluated the effects of electron beam radiation and vitamin C on liver tissue through a comprehensive approach, including biochemical analysis of serum enzymes (ALT, AST, ALP, and bilirubin), cytokine levels (IL-1β, IL-6, IL-10, and TNF-α), and oxidative stress markers (MDA and SOD). Histological and morphometric analyses were conducted on liver tissue samples collected at 7, 30, 60, and 90 days, which involved standard staining techniques and advanced imaging, including light and electron microscopy. Gene expression of Bax, Bcl-2, and caspase-3 was analyzed using real-time PCR. Results: The present study demonstrated that fractional local electron irradiation led to significant reductions in body weight and liver mass, as well as marked increases in biochemical markers of liver damage (ALT, AST, ALP, and bilirubin), inflammatory cytokines (IL-1β, IL-6, and TNF-α), and oxidative stress markers (MDA) in the irradiated group. These changes were accompanied by substantial histopathological alterations, including hepatocyte degeneration, fibrosis, and disrupted microvascular circulation. Pre-treatment with vitamin C partially mitigated these effects, reducing the severity of the liver damage, oxidative stress, and inflammation, and preserving a more favorable balance between hepatocyte proliferation and apoptosis. Overall, the results highlight the potential protective role of vitamin C in reducing radiation-induced liver injury, although the long-term benefits require further investigation. Conclusions: The present study highlights vitamin C's potential as a radioprotective agent against electron beam-induced liver damage. It effectively reduced oxidative stress, apoptosis, and inflammation, particularly in preventing the progression of radiation-induced liver fibrosis. These findings suggest that vitamin C could enhance radiotherapy outcomes by minimizing liver damage, warranting further exploration into its broader clinical applications.

Selective Hydrolysis of Ovalbumin by Zr-Based Lacunary Polyoxotungstate in Surfactant Solutions

This study aims to design an artificial metalloprotease based on a Zr-containing polyoxometalate Na8[Zr(W5O18)2] [Zr(W5)2] for the hydrolysis of ovalbumin (OVA) in the presence of different surfactants, which can be used in many areas of the biological and medical sciences, particularly for targeted proteolytic drug design. For this reason, parameters, including the free energy of binding, the chemical nature of amino acid residues, secondary structures, and electrostatic potentials, of Zr(W5)2-OVA and Zr(W5)2-OVA-surfactant were analyzed by molecular docking simulations. The investigations showed that the presence of surfactants decreases the binding affinity of Zr(W5)2 for OVA amino acids, and hydrogen bonds and van der Waals interactions are formed between Zr(W5)2 and OVA amino acids. Additionally, GROMACS further illustrated the significance of SDS and CTAB surfactants in influencing the conformational changes of the OVA that lead to selective protein hydrolysis. In agreement with molecular dynamics simulation results, the experimental analysis showed more protein hydrolysis for the Zr(W5)2-OVA-surfactant systems. For instance, circular dichroism spectroscopy indicated that Zr(W5)2-OVA-CTAB and Zr(W5)2-OVA-TX-100 were more hydrolytically efficient due to the increased level of β-structures rather than α-chains, which showed that surfactants can facilitate the accessibility of Zr(W5)2 to the cleavage sites by inducing partial unfolding of the OVA structure.

Vitamins and Radioprotective Effect: A Review

The radioprotective effect ex vivo, in vitro and in vivo of vitamins was reviewed using PubMed and Embase and conducted according to the PRISMA statement. A total of 38 articles were included in this review, which includes the radioprotective effect of vitamins from ex vivo, in vitro and in vivo studies. Vitamins A, C, D and E were used alone, in combination or with other nutritional and non-nutritional compounds. The use of vitamins in natural form or supplementation can be useful to reduce the radiation effect in the body, organs and/or cells. Only four (A, C, D and E) out of thirteen vitamins have been detected with radioprotective properties being mainly vitamin E followed by vitamin C, A and D.

ROS-Scavenging Glyco-Nanoplatform for Synergistic Antibacteria and Wound-Healing Therapy of Bacterial Keratitis

Infectious keratitis is a serious disease originating from a corneal trauma infected with bacteria, which is intractable to heal due to stubborn infection and persistent inflammation featured with high reactive...