The effects of apelin-13 against cisplatin-induced nephrotoxicity in rats

The impact of apelin-13 on cisplatin-induced endocrine pancreas damage in rats: an in vivo study

Apelin-13 is a peptide hormone that regulates pancreatic endocrine functions, and its benefits on the endocrine pancreas are of interest. This study aims to investigate the potential protective effects of apelin-13 in cisplatin-induced endocrine pancreatic damage. Twenty-four rats were divided into four groups: control, apelin-13, cisplatin, and cisplatin + apelin-13. Caspase-3, TUNEL, and Ki-67 immunohistochemical staining were used as markers of apoptosis and mitosis. NF-κB/p65 and TNFα were used to show inflammation. β-cells and α-cells were also evaluated with insulin and glucagon staining in the microscopic examination. Pancreatic tissue was subjected to biochemical analyses of glutathione (GSH) and malondialdehyde (MDA). Apelin-13 ameliorated cisplatin-induced damage in the islets of Langerhans. The immunopositivity of apelin-13 on β-cells and α-cells was found to be increased compared to the cisplatin group (p = 0.001, p = 0.001). Mitosis and apoptosis were significantly higher in the cisplatin group (p = 0.001). Apelin-13 reduced TNFα, NF-κB/p65 positivity, and apoptosis caused by cisplatin (p = 0.001, p = 0.001, p = 0.001). While cisplatin caused a significant increase in MDA levels (p = 0.001), apelin caused a significant decrease in MDA levels (p = 0.001). The results demonstrated a significant decrease in pancreatic tissue GSH levels following cisplatin treatment (p = 0.001). Nevertheless, apelin-13 significantly enhanced cisplatin-induced GSH reduction (p = 0.001). On the other hand, the serum glucose level, which was measured as 18.7 ± 2.5 mmol/L in the cisplatin group, decreased to 13.8 ± 0.7 mmol/L in the cisplatin + apelin-13 group (p = 0.001). The study shows that apelin-13 ameliorated cisplatin-induced endocrine pancreas damage by reducing oxidative stress and preventing apoptosis.

Mitigation of cisplatin-induced nephrotoxicity by chelidonic acid in Wistar rats

INTRODUCTION

Cisplatin, an anti-cancer drug is used to treat a wide range of solid tumors. Nevertheless, nephrotoxicity is the major adverse effect that restricts its clinical application. The present study focuses on the effect of chelidonic acid in cisplatin-induced nephrotoxicity.

METHODS

Wistar rats were injected with cisplatin (5 mg/kg, intraperitoneally (i.p.), once in a week for 4 weeks) and chelidonic acid (10, 20, and 40 mg/kg, per oral (p.o.) for 4 weeks). Body weight, urine, biochemical, and oxidative stress parameters were performed to evaluate the effect of chelidonic acid in cisplatin-induced nephrotoxicity in rats. Pro-inflammatory cytokines and nuclear factor erythroid 2-related factor 2 (Nrf2) concentrations were determined. Expression of phospho-AMP activated protein kinase (phospho-AMP) and hypoxia-inducible factor 1-alpha (HIF-1α) was studied with western blot. Haematoxylin and eosin, periodic acid-Schiff, and Masson's trichrome staining were used to study kidney tissues.

RESULTS

Relative kidney weight and urine output were significantly increased in cisplatin-administered rats. Whereas, albumin, and creatinine concentration were decreased, and treatment with chelidonic acid reverses these deleterious effects of cisplatin significantly. Kidney functions were improved by chelidonic acid treatment with a reduction in tumor necrosis factor-alpha (TNF-α), Interleukin-6 (IL-6), and transforming growth factor-beta (TGF-β1) concentration. The oxidative stress was decreased as compared to the cisplatin group. Furthermore, Nrf2 was significantly increased by chelidonic acid treatment. Chelidonic acid treatment significantly increased the expression of phospho-AMPK and HIF-1α in kidney tissue. Histopathological studies revealed that chelidonic acid reduced kidney damage.

CONCLUSION

The findings showed that chelidonic acid increases phospho-AMPK and HIF-1α in the kidney tissue and significantly lowers the inflammatory cytokines, thus it is an effective molecule for providing protection against cisplatin-induced nephrotoxicity.

The Yin and Yang Effect of the Apelinergic System in Oxidative Stress

Apelin is an endogenous ligand for the G protein-coupled receptor APJ and has multiple biological activities in human tissues and organs, including the heart, blood vessels, adipose tissue, central nervous system, lungs, kidneys, and liver. This article reviews the crucial role of apelin in regulating oxidative stress-related processes by promoting prooxidant or antioxidant mechanisms. Following the binding of APJ to different active apelin isoforms and the interaction with several G proteins according to cell types, the apelin/APJ system is able to modulate different intracellular signaling pathways and biological functions, such as vascular tone, platelet aggregation and leukocytes adhesion, myocardial activity, ischemia/reperfusion injury, insulin resistance, inflammation, and cell proliferation and invasion. As a consequence of these multifaceted properties, the role of the apelinergic axis in the pathogenesis of degenerative and proliferative conditions (e.g., Alzheimer's and Parkinson's diseases, osteoporosis, and cancer) is currently investigated. In this view, the dual effect of the apelin/APJ system in the regulation of oxidative stress needs to be more extensively clarified, in order to identify new potential strategies and tools able to selectively modulate this axis according to the tissue-specific profile.