Protective Effect of Exacum lawii on Cisplatin-induced Oxidative Renal Damage in Rats

Cisplatin-Induced Kidney Toxicity: Potential Roles of Major NAD+-Dependent Enzymes and Plant-Derived Natural Products

Cisplatin is an FDA approved anti-cancer drug that is widely used for the treatment of a variety of solid tumors. However, the severe adverse effects of cisplatin, particularly kidney toxicity, restrict its clinical and medication applications. The major mechanisms of cisplatin-induced renal toxicity involve oxidative stress, inflammation, and renal fibrosis, which are covered in this short review. In particular, we review the underlying mechanisms of cisplatin kidney injury in the context of NAD⁺-dependent redox enzymes including mitochondrial complex I, NAD kinase, CD38, sirtuins, poly-ADP ribosylase polymerase, and nicotinamide nucleotide transhydrogenase (NNT) and their potential contributing roles in the amelioration of cisplatin-induced kidney injury conferred by natural products derived from plants. We also cover general procedures used to create animal models of cisplatin-induced kidney injury involving mice and rats. We highlight the fact that more studies will be needed to dissect the role of each NAD⁺-dependent redox enzyme and its involvement in modulating cisplatin-induced kidney injury, in conjunction with intensive research in NAD⁺ redox biology and the protective effects of natural products against cisplatin-induced kidney injury.

Panax notoginseng saponins ameliorate cisplatin-induced mitochondrial injury via the HIF-1α/mitochondria/ROS pathway

Cisplatin is a major antineoplastic drug that is used to treat solid tumors, but its use is restricted by its nephrotoxicity. Such cisplatin‐induced nephrotoxicity (CIN) is believed to occur primarily through mitochondrial damage and reactive oxygen species (ROS) generation. Our previous studies have indicated that Panax notoginseng saponins (PNSs) mitigate CIN by enhancing hypoxia‐inducible factor 1α (HIF‐1α)‐induced mitochondrial autophagy. In this study, the role of the HIF‐1α/mitochondria/ROS pathway in PNSs protection against CIN was investigated using a rat model. A CIN model was generated by giving rats intraperitoneal injections with cisplatin (a single dose) and then treating them with or without 2‐methoxyestradiol (HIF‐1α inhibitor) and PNSs. We then measured ROS levels, superoxide dismutase, glutathione, catalase malondialdehyde and nitric oxide (to evaluate oxidative stress) and ATP, mitochondrial membrane potential and mitochondrial permeability transition pore opening (to evaluate mitochondrial function) in kidneys at different time points. We observed that PNSs remarkably reduced the levels of ROS, malondialdehyde and nitric oxide, as well as the opening of mitochondrial permeability transition pore, which is increased by cisplatin and further increased by HIF‐1α inhibition. In addition, PNSs increased the levels of superoxide dismutase, catalase and glutathione, as well as ATP and mitochondrial membrane potential in renal tissues; these are all reduced by cisplatin and further reduced by HIF‐1α inhibition. In conclusion, we demonstrate here that PNSs protects against mitochondrial damage induced by cisplatin through HIF‐1α/mitochondria/ROS.

Neuroprotective Effect of Swertiamain on Cerebral Ischemia/Reperfusion Injury by Inducing the Nrf2 Protective Pathway

Oxidative stress plays a vital role in the development of cerebral ischemic/reperfusion (I/R). Targeting oxidative stress is proposed to be an effective strategy to treat cerebral I/R injury. Gentiana macrophylla Pall is reported to have a potential protective effect against stroke. Swertiamarin (Swe), an active secoiridoid glycoside compound isolated from Gentiana macrophylla Pall, has been reported to possess antioxidative potential. This study is to explore whether Swe could prevent brain from I/R injury, and the related mechanisms of oxidative stress are also elucidated using mice middle cerebral artery occlusion (MCAO) model and primary hippocampal neurons oxygen-glucose deprivation/reperfusion (OGD/R) model. Swe (25, 100, or 400 mg/kg) was pretreated intraperitoneally for 7 days until establishment of the MCAO model, while hippocampal neurons were maintained in Swe (0.1, 1, or 10 μM) in the entire process of reoxygenation. The results indicated that Swe pretreatment markedly decreased infarct volume, apoptotic neurons, and oxidative damage and promoted neurologic recovery in vivo. It also decreased reactive oxygen species (ROS) and increased cell viability in vitro. Western blot analyses and immunofluorescence staining demonstrated that Swe pretreatment promoted Nrf2 nuclear translocation from Keap1-Nrf2 complex and enhanced the expressions of NAD(P)H: quinone oxidoreductase-1 (NQO1) and heme oxygenase-1 (HO-1) both in vivo and in vitro, while the expressions could be reversed by a Nrf2 inhibitor. The binding mode of Keap1 with Swe was also proposed by covalent molecular docking. Collectively, Swe could be considered as a promising protective agent against cerebral I/R injury through suppressing oxidative stress by activation of the Nrf2 protective pathway.

Nutritionally Available Selenocysteine Derivative Antagonizes Cisplatin-Induced Toxicity in Renal Epithelial Cells through Inhibition of Reactive Oxygen Species-Mediated Signaling Pathways

Discovery of nutritionally available agents that could antagonize cisplatin-induced nephrotoxicity is of great significance and clinical application potential. 3,3'-Diselenodipropionic acid (DSePA) is a seleno-amino acid derivative that exhibits strong antioxidant activity. Therefore, this study aimed to examine the protective effects of DSePA on cisplatin-induced renal epithelial cells damage as well as the molecular mechanisms. The results revealed that DSePA effectively inhibited cell apoptosis induced by cisplatin through suppressing the caspase activation and poly(ADP-ribose) polymerase cleavage. In addition, DSePA blocked the cisplatin-induced mitochondrial dysfunction, as evidenced by the loss of mitochondrial membrane potential and reduction of mitochondrial mass. The results of western blot analysis showed that DSePA reversed the expression level of Bcl-2 family proteins altered by cisplatin. The cisplatin-activated AKT pathway was also modulated by DSePA. Moreover, these results indicate that DSePA could protect HK-2 cells from cisplatin-induced toxicity in renal epithelial cells by inhibiting intracellular reactive oxygen species-mediated apoptosis while showing an unobvious effect on its anticancer efficacy. Taken together, this study demonstrates that selenocysteine could be further developed as novel nutritionally available agents to antagonize cisplatin-induced nephrotoxicity during cancer therapy.