Oxidative Damage as a Fundament of Systemic Toxicities Induced by Cisplatin-The Crucial Limitation or Potential Therapeutic Target?

The Effect of Thymoquinone on the TNF-α/OTULIN/NF-κB Axis Against Cisplatin-İnduced Testicular Tissue Damage

One of the adverse effects of the antineoplastic drug cisplatin (CS) is damage to testicular tissue. This study aimed to examine the potential therapeutic effect of thymoquinone (TQ), a strong antioxidant, against testicular damage caused by CS. In the experiment, 28 rats were used, and the rats were randomly divided into four groups: control (n = 7), CS (n = 7), CS + TQ (n = 7), and TQ (n = 7). The experiment was called off after all treatments were finished on day 15. Blood serum and testicular tissues were utilized for biochemical, histological, immunohistochemical, mRNA expression, and gene protein investigations. The testosterone level decreased and oxidative stress, histopathological damage, dysregulation in mitochondrial dynamics, inflammation and apoptotic cells increased in testicular tissue due to CS administration. TQ supplementation showed anti-inflammatory, antioxidant, and anti-apoptotic effects in response to CS-induced testicular damage. In addition, TQ contributed to the reduction of CS-induced toxic effects by regulating the TNF-α/OTULIN/NF-κB pathway. TQ supplementation may be a potential therapeutic strategy against CS-induced testicular damage by regulating the TNF-α/OTULIN/NF-κB axis, inhibiting inflammation, oxidative stress, and apoptosis.

Malate, a natural inhibitor of 6PGD, improves the efficacy of chemotherapy in lung cancer

OBJECTIVE

Metabolic reprogramming is an important coordinator of tumor development and resistance to therapy, such as the tendency of tumor cells to utilize glycolytic energy rather than oxidative phosphorylation, even under conditions of sufficient oxygen. Therefore, targeting metabolic enzymes is an effective strategy to overcome therapeutic resistance.

MATERIALS AND METHODS

We explored the differential expression and growth-promoting function of MDH2 by immunohistochemistry and immunoblotting experiments in lung cancer patients and lung cancer cells. Pentose phosphate pathway-related phenotypes (including ROS levels, NADPH levels, and DNA synthesis) were detected intracellularly, and the interaction of malate and proteinase 6PGD was detected in vitro. In vivo experiments using implanted xenograft mouse models to explore the growth inhibitory effect and pro-chemotherapeutic function of dimethyl malate (DMM) on lung cancer.

RESULTS

We found that the expression of malate dehydrogenase (MDH2) in the tricarboxylic acid cycle (TCA cycle) was increased in lung cancer. Biological function enrichment analysis revealed that MDH2 not only promoted oxidative phosphorylation, but also promoted the pentose phosphate pathway (PPP pathway). Mechanistically, it was found that malate, the substrate of MDH2, can bind to the PPP pathway metabolic enzyme 6PGD, inhibit its activity, reduce the generation of NADPH, and block DNA synthesis. More importantly, DMM can improve the sensitivity of lung cancer to the clinical drug cisplatin.

CONCLUSION

We have identified malate as a natural inhibitor of 6PGD, which will provide new leads for the development of 6PGD inhibitors. In addition, the metabolic enzyme MDH2 and the metabolite malate may provide a backup option for cells to inhibit their own carcinogenesis, as the accumulated malate targets 6PGD to block the PPP pathway and inhibit cell cycle progression.

The uses of zebrafish (Danio rerio) as an in vivo model for toxicological studies: A review based on bibliometrics

An in vivo model is necessary for toxicology. This review analyzed the uses of zebrafish (Danio rerio) in toxicology based on bibliometrics. Totally 56,816 publications about zebrafish from 2002 to 2023 were found in Web of Science Core Collection, with Toxicology as the top 6 among all disciplines. Accordingly, the bibliometric map reveals that "toxicity" has become a hot keyword. It further reveals that the most common exposure types include acute, chronic, and combined exposure. The toxicological effects include behavioral, intestinal, cardiovascular, hepatic, endocrine toxicity, neurotoxicity, immunotoxicity, genotoxicity, and reproductive and transgenerational toxicity. The mechanisms include oxidative stress, inflammation, autophagy, and dysbiosis of gut microbiota. The toxicants commonly evaluated by using zebrafish model include nanomaterials, arsenic, metals, bisphenol, and dioxin. Overall, zebrafish provide a unique and well-accepted model to investigate the toxicological effects and mechanisms. We also discussed the possible ways to address some of the limitations of zebrafish model, such as the combination of human organoids to avoid species differences.