The flavonoid 6-hydroxyflavone prevention of cisplatin-induced nephrotoxicity

Nephroprotective Activity of Angelica keiskei (Miq). Koidz. on Cisplatin-Induced Rats: Reducing Serum Creatinine, Urea Nitrogen, KIM-1, and Suppressing NF-kappaB p65 and COX-2

Background

The sap of Angelica keiskei (Miq). Koidz. has been reported for its abundance of chalcone contents. Chalcones have been known for their effective nephroprotective activity toward cisplatin-induced renal cells and mice.

Purpose

To investigate the effect of A. keiskei sap extract (ASEE) on kidney function parameters (serum creatinine, urea nitrogen, and kidney injury molecule-1) and the expression of NF-kappaB p65 and COX-2 in cisplatin-induced Wistar rats.

Methods

In vivo nephroprotective activity of ASEE at 1000 and 1500 mg/kg BW/day doses for 10 days on cisplatin (5 mg/kg BW) induced nephrotoxicity was evaluated on Wistar rats. Quercetin 20 mg/kg BW/day was used as the control drug. Cisplatin inducement was given on day 7. The BW was measured every day. On day 11, the rats were euthanized, and their blood was taken intracardially for creatinine and urea nitrogen analysis. Histopathological analysis was carried out on the right kidney, and KIM-1 levels in the left kidney were measured. The Western blot technique evaluated the NF-kappaB p65 and COX-2 expression in the kidney. All data obtained were compared to the cisplatin group (negative control). The total flavonoids and chalcones in ASEE were also determined.

Results

Pretreatment with ASEE reduces the BW of Wistar rats, and significantly reduces creatinine and KIM-1 levels, but does not significantly reduce the levels of urea nitrogen, the expression of NF-kappaB p65, and COX-2 in the kidney of cisplatin-induced Wistar rats. The total flavonoid content in ASEE is 8.755 g QE/100 g extract and the total chalcone content is 5.532 g IBCE/100 g extract.

Conclusion

The sap of Angelica keiskei (Miq). Koidz. reveal the potential to protect the kidneys against cisplatin-induced toxicity. The nephroprotective activity may be attributed to the antioxidant and anti-inflammatory properties of the flavonoids and the chalcones contained in the sap of Angelica keiskei (Miq). Koidz.

Inhibitory interaction of flavonoids with organic cation transporter 2 and their structure-activity relationships for predicting nephroprotective effects

Organic cation transporter 2 (OCT2) is mainly responsible for the renal secretion of various cationic drugs, closely associated with drug-induced acute kidney injury (AKI). Screening and identifying potent OCT2 inhibitors with little toxicity in natural products in reducing OCT2-mediated AKI is of great value. Flavonoids are enriched in various vegetables, fruits, and herbal products, and some were reported to produce transporter-mediated drug-drug interactions. This study aimed to screen potential inhibitors of OCT2 from 96 flavonoids, assess the nephroprotective effects on cisplatin-induced kidney injury, and clarify the structure-activity relationships of flavonoids with OCT2. Ten flavonoids exhibited significant inhibition (>50%) on OCT2 in OCT2-HEK293 cells. Among them, the six most potent flavonoid inhibitors, including pectolinarigenin, biochanin A, luteolin, chrysin, 6-hydroxyflavone, and 6-methylflavone markedly decreased cisplatin-induced cytotoxicity. Moreover, in cisplatin-induced renal injury models, they also reduced serum blood urea nitrogen (BUN) and creatinine levels to different degrees, the best of which was 6-methylflavone. The pharmacophore model clarified that the aromatic ring, hydrogen bond acceptors, and hydrogen bond donors might play a vital role in the inhibitory effect of flavonoids on OCT2. Thus, our findings would pave the way to predicting the potential risks of flavonoid-containing food/herb-drug interactions in humans and optimizing flavonoid structure to alleviate OCT2-related AKI.

Salvianolic Acid C Protects against Cisplatin-Induced Acute Kidney Injury through Attenuation of Inflammation, Oxidative Stress and Apoptotic Effects and Activation of the CaMKK-AMPK-Sirt1-Associated Signaling Pathway in Mouse Models

Acute kidney injury (AKI) is a sudden reduction in kidney activity and has a high mortality rate. Salvianolic acid C (SAC), one of the main polyphenolic components of Salvia miltiorrhiza, displays significant pharmacologically active effects. An animal model of cisplatin-induced kidney injury was used to study the potential of SAC to improve AKI. First, SAC was administered intraperitoneally in mice for 10 consecutive days, and then cisplatin was administered intraperitoneally on day 7 to establish a nephrotoxicity mouse model. SAC mitigated renal histological changes, blood creatinine (CRE) and blood urea nitrogen (BUN) production and the levels of inflammatory mediators in the cisplatin-induced AKI. Furthermore, malondialdehyde (MDA) levels were reduced and glutathione (GSH) was increased after intraperitoneal injection (i.p.) administration of SAC. In addition, based on Western blot data, SAC reduced the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) activation in mouse renal tissues. Finally, SAC diminished the level of TLR-4 expression and enhanced the production of several antioxidative enzymes (superoxidase dismutase (SOD1), glutathione peroxidase (GPx3), catalase, nuclear-factor-erythroid-2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1)), Sirtuin 1 (Sirt1), p-AMP-activated protein kinase (AMPK) and p-Ca²⁺/calmodulin-dependent protein kinase kinase (CaMKK). In addition, Sirt1 inhibition (EX 527) inverted the effect of SAC against cisplatin-induced nephrotoxicity. Collectively, SAC provides a therapeutic target with promising clinical potential after cisplatin treatment by attenuating oxidative stress and inflammation.