Formononetin ameliorates cisplatin-induced hair cell death via activation of the PI3K/AKT-Nrf2 signaling pathway

Cisplatin (CDDP) stands as a highly effective chemotherapeutic agent; however, its ototoxicity remains a perplexing challenge in the field. Formononetin (FMNT), a potent flavonoid isolated from Astragalus membranaceus, displays a diverse range of promising pharmacological activities, encompassing antioxidant, anti-apoptotic, and anti-inflammatory effects. Nonetheless, the advantageous effects of FMNT on cisplatin-induced cochlear hair cell injury demand further investigation. This study aimed to assess the protective properties of FMNT against cisplatin-induced hair cell damage by conducting in vitro assays on explant-cultured cochlear hair cells. The findings revealed that FMNT exhibited a notable reduction in cisplatin-induced hair cell apoptosis. Also, FMNT effectively mitigated the accumulation of reactive oxygen species and mitochondrial damage in cochlear explants exposed to cisplatin, while also restoring the turnover of the reduced glutathione (GSH)/glutathione disulfide (GSSG) ratio. Furthermore, our study demonstrated that FMNT protects hair cells against CDDP injury through the activation of the PI3K/AKT-Nrf2 signaling pathway. Consequently, formononetin emerges as a potential therapeutic agent for the treatment of cisplatin-induced ototoxicity.

Formononetin Ameliorates Renal Dysfunction, Oxidative Stress, Inflammation, and Apoptosis and Upregulates Nrf2/HO-1 Signaling in a Rat Model of Gentamicin-Induced Nephrotoxicity

Gentamicin (GEN) is a bactericidal aminoglycoside known to cause nephrotoxicity. Formononetin (FN) is a potent flavonoid that exhibits numerous promising pharmacological activities. In this study, we have assessed the nephroprotective efficacy of FN against GEN-induced renal injury in rats. Rats were orally administered with FN (60 mg/kg/day, for 2 weeks) and were co-treated with intraperitoneal (i.p.) injection of GEN (100 mg/kg/day) during the days 8–14. GEN-treated rats demonstrated increased urea and creatinine levels in serum associated with marked histopathological changes in the kidney. Malondialdehyde (MDA) and protein carbonyl contents were elevated, whereas glutathione concentration and catalase and superoxide dismutase activities were lowered in GEN-administered rats. The FN largely prevented tissue damage, attenuated renal function, reduced MDA and protein carbonyl, and enhanced antioxidant capacity in the kidney of GEN-administrated animals. The kidney of GEN-treated rats demonstrated elevated Bax and caspase-3 protein expression, accompanied by lowered Bcl-2 protein expression, an effect that FN attenuated. Moreover, FN treatment caused upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) expression in renal tissue of GEN-intoxicated animals. Collectively, FN protects against GEN-caused renal damage via exhibiting antioxidant, anti-inflammatory, and antiapoptotic activities and augmenting Nrf2 signaling, suggesting FN as a promising agent for preventing drug-induced organ damage.

Formononetin Upregulates Nrf2/HO-1 Signaling and Prevents Oxidative Stress, Inflammation, and Kidney Injury in Methotrexate-Induced Rats

Acute kidney injury (AKI) is a serious complication of methotrexate (MTX). This study explored the protective effect of the isoflavone formononetin (FN) against MTX nephrotoxicity with an emphasis on oxidative stress, inflammation, and nuclear factor (erythroid-derived 2)-like 2/heme oxygenase 1 (Nrf2/HO-1) signaling. Rats received FN (10, 20, and 40 mg/kg) for 10 days and a single dose of MTX on day 7. MTX induced kidney injury was characterized by increased serum creatinine and urea, kidney injury molecule-1 (Kim-1), and several histological alterations. FN ameliorated kidney function and inhibited the renal tissue injury induced by MTX. Reactive oxygen species (ROS), lipid peroxidation (LPO), nitric oxide, and 8-Oxo-2′-deoxyguanosine were increased, whereas antioxidant defenses were diminished in the kidney of MTX-administered rats. In addition, MTX upregulated renal iNOS, COX-2, TNF-α, IL-1β, Bax, caspase-9, and caspase-3, and decreased Bcl-2, Nrf2, and HO-1. FN suppressed oxidative stress, LPO, DNA damage, iNOS, COX-2, proinflammatory cytokines, and apoptosis, and boosted Bcl-2, antioxidants, and Nrf2/HO-1 signaling in MTX-administered rats. In conclusion, FN prevents MTX-induced AKI by activating Nrf2/HO-1 signaling and attenuates oxidative damage and inflammation. Thus, FN may represent an effective adjuvant that can prevent MTX nephrotoxicity, pending further mechanistic studies.

Organic anion transporters also mediate the drug-drug interaction between imipenem and cilastatin

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Dehydropeptidase-1 (DPEP1) mediates the DDI between imipenem and cilastatin as a traditional theory is limited.

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Transporter-mediated DDI between imipenem and cilastatin has not been clarified.

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Imipenem and cilastatin are the substrates of hOAT1/3.

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This study first demonstrates that OAT1 and OAT3 also mediate the DDI between imipenem and cilastatin.

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It also supplies a new ideal to make a compound preparation through the DDI mediated by transporters.

This study aimed to clarify that organic anion transporters (OATs) mediate the drug–drug interaction (DDI) between imipenem and cilastatin. After co-administration with imipenem, the plasma concentrations and the plasma concentration-time curve (AUC) of cilastatin were significantly increased, while renal clearance and cumulative urinary excretion of cilastatin were decreased. At the same time, imipenem significantly inhibited the uptake of cilastatin in rat kidney slices and in human OAT1 (hOAT1)-HEK293 and human OAT3 (hOAT3)-HEK293 cells. Probenecid, p-aminohippurate, and benzylpenicillin inhibited the uptake of imipenem and cilastatin in rat kidney slices and in hOAT1- and hOAT3-HEK 293 cells, respectively. The uptakes of imipenem and cilastatin in hOAT1- and hOAT3-HEK 293 cells were significantly higher than that in mock-HEK-293 cells. Moreover, the K_m values of cilastatin were increased in the presence of imipenem with unchanged V_max, indicating that imipenem inhibited the uptake of cilastatin in a competitive manner. When imipenem and cilastatin were co-administered, the level of imipenem was higher compared with imipenem alone both in vivo and in vitro. But, cilastatin significantly inhibited the uptake of imipenem when dehydropeptidase-1 (DPEP1) was silenced by RNAi technology in hOAT1- and hOAT3-HEK 293 cells. In conclusion, imipenem and cilastatin are the substrates of OAT1 and OAT3. OAT1 and OAT3 mediate the DDI between imipenem and cilastatin. Meanwhile, cilastatin also reduces the hydrolysis of imipenem by inhibiting the uptake of imipenem mediated by OAT1 and OAT3 in the kidney as a complement.

Inhibition of Intracellular ROS Accumulation by Formononetin Attenuates Cisplatin-Mediated Apoptosis in LLC-PK1 Cells

Cisplatin is a well-known anticancer drug frequently used for treating solid tumors, including ovarian, testicular, bladder, and cervical tumors. However, usage of cisplatin has been limited because of its adverse effects, particularly nephrotoxicity. Therefore, the present study sought to investigate the protective effect of formononetin against cisplatin-induced cytotoxicity in LLC-PK1 pig kidney epithelial cells as well as the anticancer effect of cisplatin in three different human cervical cancer cell lines, including HeLa, SiHa, and CaSKi cells. We first demonstrated that formononetin strongly prevented cisplatin-induced LLC-PK1 cell death. Although formononetin had no anticancer effect, it did not interrupt the anticancer effect of cisplatin in human cervical carcinoma cell lines. Furthermore, the treatment with formononetin reduced reactive oxygen species (ROS) accumulation and chromatin condensation. The percentage of Annexin V-positive cells also increased following cisplatin treatment. Finally, formononetin-inhibited c-Jun N-terminal kinase (JNK) phosphorylation, cleavage of caspase-8 and caspase-3, and the ratio of Bax to Bcl-2 increased with cisplatin. Taken together, these findings suggest that formononetin may be a possible option to prevent nephrotoxicity induced by cisplatin during treatment for cervical cancer.

Targeting P-glycoprotein and SORCIN: Dihydromyricetin strengthens anti-proliferative efficiency of adriamycin via MAPK/ERK and Ca2+ -mediated apoptosis pathways in MCF-7/ADR and K562/ADR

Recently, a new target Ca²⁺ -binding protein SORCIN was reported to participate in multidrug resistance (MDR) in cancer. Here we aim to investigate whether dihydromyricetin (DMY), a dihydroflavonol compound with anti-inflamatory, anti-oxidant, anti-bacterial and anti-tumor actions, reverses MDR in MCF-7/ADR and K562/ADR and to elucidate its potential molecular mechanism. DMY enhanced cytotoxicity of adriamycin (ADR) by downregulating MDR1 mRNA and P-gp expression through MAPK/ERK pathway and also inhibiting the function of P-gp significantly. Meanwhile, DMY decreased mRNA and protein expression of SORCIN, which resulted in elevating intracellular free Ca²⁺ . Finally, we investigated co-administration ADR with DMY remarkably increased ADR-induced apoptosis. Further study showed DMY elevated ROS levels and caspase-12 protein expression, which signal apoptosis in endoplasmic reticulum. At the same time, proteins related to mitochondrial apoptosis were also changed such as Bcl-2, Bax, caspase-3, caspase-9, and PARP. Finally, nude mice model also demonstrated that DMY strengthened anti-tumor activity of ADR in vivo. In conclusion, DMY reverses MDR by downregulating P-gp, SORCIN expression and increasing free Ca²⁺ , as well as, inducing apoptosis in MCF-7/ADR and K562/ADR. These fundamental findings provide evidence for further clinical research in application of DMY as an assistant agent in the treatment of cancer.