Geraniol Averts Methotrexate-Induced Acute Kidney Injury via Keap1/Nrf2/HO-1 and MAPK/NF-κB Pathways

Geraniol and citral: recent developments in their anticancer credentials opening new vistas in complementary cancer therapy

About 10 million people are diagnosed with cancer each year. Globally, it is the second leading cause of death after heart disease, and by 2035, the death toll could reach 14.6 million. Several drugs and treatments are available to treat cancer, but survival rates remain low. Many studies in recent years have shown that plant-derived monoterpenes, particularly geraniol and citral, are effective against various cancers, including breast, liver, melanoma, endometrial, colon, prostate, and skin cancers. This trend has opened new possibilities for the development of new therapeutics or adjuvants in the field of cancer therapy. These monoterpenes can improve the efficacy of chemotherapy by modulating many signaling molecules and pathways within tumors. Analysis of reports on the anticancer effects published in the past 5 years provided an overview of the most important results of these and related properties. Also, the molecular mechanisms by which they exert their anticancer effects in cell and animal studies have been explained. Therefore, this review aims to highlight the scope of geraniol and citral as complementary or alternative treatment options in cancer therapy.

Plant-derived bioactive compounds and their novel role in central nervous system disorder treatment via ATF4 targeting: A systematic literature review

Central nervous system (CNS) disorders exhibit exceedingly intricate pathogenic mechanisms. Pragmatic and effective solutions remain elusive, significantly compromising human life and health. Activating transcription factor 4 (ATF4) participates in the regulation of multiple pathophysiological processes, including CNS disorders. Considering the widespread involvement of ATF4 in the pathological process of CNS disorders, the targeted regulation of ATF4 by plant-derived bioactive compounds (PDBCs) may become a viable strategy for the treatment of CNS disorders. However, the regulatory relationship between PDBCs and ATF4 remains incompletely understood. Here, we aimed to comprehensively review the studies on PDBCs targeting ATF4 to ameliorate CNS disorders, thereby offering novel directions and insights for the treatment of CNS disorders. A computerized search was conducted on PubMed, Embase, Web of Science, and Google Scholar databases to identify preclinical experiments related to PDBCs targeting ATF4 for the treatment of CNS disorders. The search timeframe was from the inception of the databases to December 2023. Two assessors conducted searches using the keywords "ATF4," "Central Nervous System," "Neurological," "Alzheimer's disease," "Parkinson's Disease," "Stroke," "Spinal Cord Injury," "Glioblastoma," "Traumatic Brain Injury," and "Spinal Cord Injury." Overall, 31 studies were included, encompassing assessments of 27 PDBCs. Combining results from in vivo and in vitro studies, we observed that these PDBCs, via ATF4 modulation, prevent the deposition of amyloid-like fibers such as Aβ, tau, and α-synuclein. They regulate ERS, reduce the release of inflammatory factors, restore mitochondrial membrane integrity to prevent oxidative stress, regulate synaptic plasticity, modulate autophagy, and engage anti-apoptotic mechanisms. Consequently, they exert neuroprotective effects in CNS disorders. Numerous PDBCs targeting ATF4 have shown potential in facilitating the restoration of CNS functionality, thereby presenting expansive prospects for the treatment of such disorders. However, future endeavors necessitate high-quality, large-scale, and comprehensive preclinical and clinical studies to further validate this therapeutic potential.

Valsartan Mitigates the Progression of Methotrexate-Induced Acute Kidney Injury in Rats via the Attenuation of Renal Inflammation and Oxidative Stress

Background

Methotrexate (MTX) is a folic acid antagonist, commonly administered for the treatment of a variety of cancers. However, methotrexate toxicity including bone marrow suppression and hepatic and renal toxicity limits its use. Angiotensin AT1 receptor blockers including Valsartan (Val) possess the ability to ameliorate MTX-induced toxicity through various mechanisms. In this study, we explored the potential reno-protective effects of Val against MTX-induced acute kidney injury in rats.

Methods

Twenty-four Wistar rats were randomly segregated into 3 groups. Group 1 served as the control group and received an oral dose of 1mL/kg of normal saline. Group 2 received a single dose of 20 mg/kg of MTX intraperitoneally (IP) for 5 days. Group 3 received a single IP dose of 20 mg/kg of MTX followed by an oral dose of 10 mg/kg of Valsartan for 5 days. At the end of the experiment, the levels of serum kidney biomarkers, inflammatory and oxidative stress markers were accessed. Furthermore, the effect of MTX on kidney tissue histology was examined.

Results and discussion

Our results showed that MTX treatment increased the level of serum kidney and inflammatory biomarkers and decreased the level of antioxidants SOD and GSH while increasing the lipid peroxidation contents. Furthermore, MTX treatment caused structural changes to kidney histology. However, the administration of Val significantly prevented these changes.

Conclusion

Valsartan possesses nephroprotective potential and might serve as a potential therapeutic strategy against MTX-induced kidney injury.

Involvement of Nrf2-PPAR-γ signaling in Coenzyme Q10 protecting effect against methotrexate-induced testicular oxidative damage

Studies have identified Coenzyme Q10 (CoQ10) as a promising agent in improving idiopathic male infertility; however, its role in chemically or environmentally induced testicular dysfunction is not well-established. We investigated the potential of CoQ10 to attenuate methotrexate (MTX)-induced testicular damage and to identify molecular targets of CoQ10 effects. Wistar rats received a single intraperitoneal dose of 20 mg/kg MTX on the fifth day of the 10-day experimental protocol. 100 mg/kg CoQ10 was given orally daily for ten days, alone or combined with MTX. The testes of MTX-treated animals showed thickened tunica albuginea, distortion of seminiferous tubules with a marked reduction of germinal lining, a few primary spermatocytes with no spermatozoa, apoptotic cells, congested sub-capsular and interstitial blood vessels, and interstitial edema. Reduction of reproductive hormones and increased oxidative, inflammatory, and apoptotic biomarkers levels were also seen in the MTX-treated rats. CoQ10 + MTX-treated rats were protected against MTX-induced testicular histological changes and showed improvement in testosterone, luteinizing-, and follicle-stimulating hormone serum levels compared to the MTX group. The testes of the CoQ10 + MTX-treated rats showed reduced malondialdehyde, myloperoxidase, tumor necrosis factor -α, interleukin-6 and -1β and Bax: Bcl2 ratio and enhanced glutathione, and catalase compared to MTX alone. CoQ10 enhanced MTX-induced downregulation of Nrf2 and PPAR-γ signaling and modulated its downstream targets, the inducible nitric oxide synthase, NF-κB, Bax, and Bcl2. In conclusion, CoQ10 targeted the Nrf2-PPAR-γ signaling loop and its downstream pathways, mitigating MTX-induced oxidative stress-related damages and alleviating the testicular dysfunction MTX caused. Our data suggest Nrf2-PPAR-γ signaling as a potential therapeutic target in testicular toxicity, where oxidative stress, inflammation, and apoptosis trigger damage.

NRF2 in kidney physiology and disease

The role of NRF2 in kidney biology has received considerable interest over the past decade. NRF2 transcriptionally controls genes responsible for cellular protection against oxidative and electrophilic stress and has anti-inflammatory functions. NRF2 is expressed throughout the kidney and plays a role in salt and water handling. In disease, animal studies show that NRF2 protects against tubulointerstitial damage and reduces interstitial fibrosis and tubular atrophy, and may slow progression of polycystic kidney disease. However, the role of NRF2 in proteinuric glomerular diseases is controversial. Although the NRF2 inducer, bardoxolone methyl (CDDO-Me), increases glomerular filtration rate in humans, it has not been shown to slow disease progression in diabetic kidney disease and Alport syndrome. Furthermore, bardoxolone methyl was associated with negative effects on fluid retention, proteinuria, and blood pressure. Several animal studies replicate findings of worsened proteinuria and a more rapid progression of kidney disease, although considerable controversy exists. It is clear that further study is needed to better understand the effects of NRF2 in the kidney. This review summarizes the available data to clarify the promise and risks associated with targeting NRF2 activity in the kidney.

Inhibitory interaction of flavonoids with organic anion transporter 3 and their structure-activity relationships for predicting nephroprotective effects

The organic anion transporter 3 (OAT3), an important renal uptake transporter, is associated with drug-induced acute kidney injury (AKI). Screening and identifying potent OAT3 inhibitors with little toxicity in natural products, especially flavonoids, in reducing OAT3-mediated AKI is of great value. The five strongest OAT3 inhibitors from the 97 flavonoids markedly decreased aristolochic acid I-induced cytotoxicity and alleviated methotrexate-induced nephrotoxicity. The pharmacophore model clarified hydrogen bond acceptors and hydrophobic groups are the critical pharmacophores. These findings would provide valuable information in predicting the potential risks of flavonoid-containing food/herb-drug interactions and optimizing flavonoid structure to alleviate OAT3-related AKI.

Intra-articular delivery of geraniol encapsulated by pH/redox-responsive nanogel ameliorates osteoarthritis by regulating oxidative stress and inflammation

Osteoarthritis (OA) remains a challenging condition due to limited drug bioavailability within the avascular and dense cartilage matrix. This study introduces a pH/redox-responsive nanogel for enhanced delivery of geraniol in OA therapy. We investigated geraniol's role in preventing chondrocyte matrix degradation and designed a pH/redox-responsive nanogel as a delivery platform. Our methods included Western blot, histological staining, and immunohistochemistry. Geraniol treatment reduced Keap1 expression while elevating Nrf2 and HO-1 levels, effectively inhibiting cartilage matrix degradation. The pH/redox-responsive nanogel further enhanced geraniol's therapeutic impact. Our study demonstrates that geraniol encapsulated within a pH/redox-responsive nanogel mitigates OA by regulating oxidative stress and inflammation. This innovative approach holds potential as an effective OA therapeutic strategy.

Nrf2/HO-1 as a therapeutic target in renal fibrosis

Chronic kidney disease (CKD) is one of the most prevalent chronic diseases and affects between 10 and 14 % of the world's population. The World Health Organization estimates that by 2040, the disease will be fifth in prevalence. End-stage CKD is characterized by renal fibrosis, which can eventually lead to kidney failure and death. Renal fibrosis develops due to multiple injuries and involves oxidative stress and inflammation. In the human body, nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in the expression of antioxidant, anti-inflammatory, and cytoprotective genes, which prevents oxidative stress and inflammation damage. Heme oxygenase (HO-1) is an inducible homolog influenced by heme products and after exposure to cellular stress inducers such as oxidants, inflammatory chemokines/cytokines, and tissue damage as an outcome or downstream of Nrf2 activation. HO-1 is known for its antioxidative properties, which play an important role in regulating oxidative stress. In renal diseases-induced tissue fibrosis and xenobiotics-induced renal fibrosis, Nrf2/HO-1 has been targeted with promising results. This review summarizes these studies and highlights the interesting bioactive compounds that may assist in attenuating renal fibrosis mediated by HO-1 activation. In conclusion, Nrf2/HO-1 signal activation could have a renoprotective effect strategy against CKD caused by oxidative stress, inflammation, and consequent renal fibrosis.

L-methionine protects against nephrotoxicity induced by methotrexate through modulation of redox status and inflammation

Objective: Methotrexate (MTX) is a drug used in the treatment of cancer and autoimmune disorders; however, its clinical use is limited because of serious side effects including renal toxicity. This study aimed to investigate the protective effect of Lmethionine (L-Met) on MTX toxicity in the kidneys of rats.Methods: Thirty male rats were divided equally into five groups: control (saline), Met400 (400 mg/kg L-Met), MTX (20 mg/kg MTX), MTX-Met300 (300 mg/kg L-Met and 20 mg/kg MTX), and MTX-Met400 (400 mg/kg L-Met and 20 mg/kg MTX). Rats were euthanized one day after the last dose administration (day 16) and serum and renal tissue samples were collected. Renal function and injury indices, oxidative stress/antioxidant indices and proinflammatory cytokines were evaluated.Results: The results showed that L-Met could effectively counteract the nephrotoxic effects of MTX, in a dose-related manner, by improving most of the tested parameters. Furthermore, the higher dose of L-Met was able to restore several parameters to normal levels. In addition, investigation of MTX-induced hematological changes revealed a corrective potential of L-Met.Conclusion: L-Met can be an effective adjuvant therapy to modulate renal toxicity associated with MTX because of its antioxidant and antiinflammatory effects.

L-carnitine reverses methotrexate-induced nephrotoxicity in experimental rat model: Insight on SIRT1/PGC-1α/Nrf2/HO-1 axis

Methotrexate (MTX) is a chemotherapeutic agent used for treating several types of cancer as well as psoriasis and rheumatoid arthritis, but its use is limited due to its nephrotoxicity. The purpose of this research work was to observe ameliorative effects of L-carnitine (LC) toward renal toxicity caused by MTX and mechanisms responsible for these effects. Thirty-two male Sprague-Dawley rats were divided into four groups (eight rats/group), control group (received saline), MTX group (20 mg/kg/i.p. once), LC group (500 mg/kg/i.p. for 5 days), and MTX + LC group (received a single MTX dose 20 mg/kg/i.p. followed by LC 500 mg/kg/i.p. for 5 days). Histopathological examinations, lipid oxidation marker, malondialdehyde (MDA), and the antioxidant superoxide dismutase (SOD) as well as inflammatory (tumor necrosis factor-α [TNF-α] and interleukin-6 [IL-6]) and apoptotic markers (Bax, Bcl2, and caspase-3) were used to assess renal toxicity. Moreover, the protein levels of silent information regulator 1 (SIRT1) and its downstream signaling targets, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), and nuclear factor erythroid 2-related factor 2 (Nrf2) in addition to heme oxygenase-1 (HO-1) were measured. LC significantly protected against MTX-induced nephrotoxicity. It ameliorated MTX-induced renal histopathological changes and diminished MTX-induced renal oxidative stress, renal inflammation, and apoptosis. LC also upregulated the expression of SIRT1 and PGC-1 as well as Nrf2 and HO-1. By controlling the expression of renal SIRT1/PGC-1/Nrf2/HO-1, LC displayed antioxidant, anti-inflammatory, and anti-apoptotic activities. Hence, using LC supplements may help prevent negative MTX side effects.

Calycosin protects against chronic prostatitis in rats via inhibition of the p38MAPK/NF-κB pathway

Currently, the effect and molecular mechanism of calycosin, the main active ingredient of Qinshi Simiao San, which can alleviate chronic prostatitis (CP), on CP remain unclear. This study aimed to elucidate the potential mechanism of action of calycosin in CP in a rat CP model. The prostate tissue morphology was evaluated based on hematoxylin-eosin staining. Enzyme-linked immunosorbent assay was conducted to evaluate inflammatory cytokine and immune factor levels (secretory immunoglobulin A [SIgA]; immunoglobulin G [IgG]) in prostate tissues and serum. Additionally, representative biomarkers of oxidative stress, including malondialdehyde, superoxide dismutase, and catalase were detected using detection kits, and reactive oxygen species release was evaluated using immunofluorescence staining. Furthermore, the p38 mitogen-activated protein kinase (p38MAPK)/NF-kappaB (NF-κB) signaling pathway was analyzed by western blotting. The results showed that calycosin substantially ameliorated the pathological damage to prostate tissues of the CP rats. Moreover, calycosin significantly downregulated interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha, IgG, and SIgA levels. Furthermore, we found that calycosin considerably suppressed oxidative stress and inhibited the activation of the p38MAPK/NF-κB signaling pathway in rats with CP. In summary, our findings revealed that calycosin protects against CP in rats by inhibiting the p38MAPK/NF-κB pathway.

Febuxostat attenuates aluminum chloride-induced hepatorenal injury in rats with the impact of Nrf2, Crat, Car3, and MNK-mediated apoptosis

Aluminum (Al) is a ubiquitous xenobiotic with known toxicity for both humans and animals. Our study was conducted to investigate the protective role of febuxostat (Feb) against aluminum chloride (AlCl3)-induced hepatorenal injury in rats. Hepatorenal injury was induced by oral administration of AlCl3 (40 mg/kg b.w.), for 2 months. Twenty-four male Sprague-Dawley rats were randomly allocated into four groups (six rats/group). The first group received the vehicle thought the experiment. The second group was considered as a control positive group. The third and fourth groups received oral treatment of Feb (10 mg/kg.b.w.) and (15 mg/kg.b.w.), respectively with AlCl3, concurrently for 2 months. Twenty-four hours, after the last treatment, serum biochemical, molecular, histopathology, and immunohistochemical studies were evaluated. Our findings showed that rats intoxicated with Alcl3 had disturbed biochemical picture. In addition, intoxication with AlCl3 increased oxidative stress and apoptosis, as demonstrated by an increase in malodialdeyde (MDA), carnitine o-acetyltransferase (Crat), and carbonic anhydrase (Car3) with a decrease in glutathione (GSH), MAP kinase-interacting serine/threonine kinase (MNK) and nuclear factor-erythroid 2-related factor 2 (Nrf2) mRNA expression. Furthermore, the levels of tumor necrosis factor-alpha (TNF-α) and the levels of caspase-3 were elevated with sever hepatic and renal pathological changes. Conversely, Feb (15 mg/kg.b.w.) could improve the serum biochemical indices and repressed MDA, Crat, and Car3 levels, whereas it increased GSH, MNK, and Nrf2 levels. Feb inhibited the apoptotic effect of AlCl3 in the liver and kidney by decreasing caspase-3 and TNF-α expression. The protective effect of Feb against AlCl3 toxicity was confirmed by histopathological findings. Moreover, molecular docking studies supported the anti-inflammatory effect of Feb due to its significant binding interactions with cyclooxygenase-1 (COX-1), NF-kappa-B-inducing kinase (NIK), and mitogen-activated protein kinases-p38 (MAPK-p38). The findings suggest that Feb system Feb can avert Alcl3-induced hepatotoxicity and nephrotoxicity by enhancing the antioxidant defense system, and inhibiting the inflammatory cascade and apoptosis.

Dihydromyricetin Modulates Nrf2 and NF-κB Crosstalk to Alleviate Methotrexate-Induced Lung Toxicity

BACKGROUND

Methotrexate (MTX) is an effective anticancer, anti-inflammatory, and immunomodulatory agent. However, it induces a serious pneumonitis that leads to irreversible fibrotic lung damage. This study addresses the protective role of the natural flavonoid dihydromyricetin (DHM) against MTX-induced pneumonitis via modulation of Nrf2/NF-κB signaling crosstalk.

METHODS

Male Wistar rats were divided into 4 groups: control, which received the vehicle; MTX, which received a single MTX (40 mg/kg, i.p) at day 9 of the experiment; (MTX + DHM), which received oral DHM (300 mg/kg) for 14 days and methotrexate (40 mg/kg, i.p) on the 9th day; and DHM, which received DHM (300 mg/kg, p.o) for 14 days.

RESULTS

Lung histopathological examination and scoring showed a decline in MTX-induced alveolar epithelial damage and decreased inflammatory cell infiltration by DHM treatment. Further, DHM significantly alleviated the oxidative stress by decreasing MDA while increasing GSH and SOD antioxidant levels. Additionally, DHM suppressed the pulmonary inflammation and fibrosis through decreasing levels of NF-κB, IL-1β, and TGF-β1 while promoting the expression of Nrf2, a positive regulator of antioxidant genes, and its downstream modulator, HO-1.

CONCLUSION

This study identified DHM as a promising therapeutic target against MTX-induced pneumonitis via activation of Nrf2 antioxidant signaling while suppressing the NF-κB mediated inflammatory pathways.

Methotrexate-Induced Alteration of Renal Aquaporins 1 and 2, Oxidative Stress and Tubular Apoptosis Can Be Attenuated by Omega-3 Fatty Acids Supplementation

Methotrexate (MTX) is a potent anti-cancer drug, commonly associated with nephrotoxicity via the induction of oxidative stress and apoptosis with alteration of renal water channel proteins, namely aquaporins (AQPs). Omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) have shown cytoprotective effects through their anti-oxidant and antiapoptotic activities. The present study aims for the first time to explore the role of LC-PUFA against MTX-induced nephrotoxicity. Rats were divided into the following groups: saline control, LC-PUFA control, MTX, MTX + LC-PUFA (150 mg/kg), or MTX + LC-PUFA (300 mg/kg). Then, H&E staining and immunohistochemical staining for the anti-apoptosis marker B-cell lymphoma 2 (BCL-2), the apoptosis marker BCL2-Associated X Protein (BAX), the proinflammatory marker Nuclear factor kappa B (NF-kB), AQPs 1 and 2 were performed in kidney sections with an assessment of renal oxidative stress. The MTX caused a renal histopathological alteration, upregulated renal BAX and NF-kB, downregulated Bcl-2 and AQP1, altered the distribution of AQP2, and caused oxidative stress. The LC-PUFA attenuated the pathological changes and decreased renal BAX and NF-kB, increased BCL-2 and AQP1, restored the normal distribution of AQP2, and decreased the oxidative stress. Therefore, LC-PUFA is a good adjuvant to MTX to prevent its adverse effects on kidneys through its antiapoptotic, antioxidant, and anti-inflammatory effect and its role in the restoration of the expression of AQPs 1 and 2.

Renal Ischemia/Reperfusion Mitigation via Geraniol: The Role of Nrf-2/HO-1/NQO-1 and TLR2,4/MYD88/NFκB Pathway

BACKGROUND

Renal ischemia/reperfusion injury is a clinically recurrent event during kidney transplantation. Geraniol is a natural monoterpene essential oil component. This study aimed to inspect geraniol's reno-protective actions against renal I/R injury with further analysis of embedded mechanisms of action through scrutinizing the Nrf-2/HO-1/NQO-1 and TLR2,4/MYD88/NFκB signaling pathways.

METHODS

Wistar male rats were randomized into five groups: Sham, Sham + geraniol, Renal I/R, and two Renal I/R + geraniol groups representing two doses of geraniol (100 and 200 mg/kg) for 14 days before the renal I/R. Renal I/R was surgically induced by occluding both left and right renal pedicles for 45 min, followed by reperfusion for 24 h. A docking study was performed to anticipate the expected affinity of geraniol towards three protein targets: hTLR4/MD2, hTLR2, and hNrf2/Keap1.

RESULTS

Renal I/R rats experienced severely compromised renal functions, histological alteration, oxidative stress status, escalated Nrf-2/HO-1/NQO-1, and amplified TLR2,4/MYD88/NFκB. Geraniol administration ameliorated renal function, alleviated histological changes, and enhanced Nrf-2/HO-1/NQO-1 with a subsequent intensification of antioxidant enzyme activities. Geraniol declined TLR2,4/MYD88/NFκB with subsequent TNF-α, IFN-γ, MCP-1 drop, Bax, caspase-3, and caspase-9 reduction IL-10 and Bcl-2 augmentation. Geraniol exhibited good fitting in the binding sites of the three in silico examined targets.

CONCLUSIONS

Geraniol might protect against renal I/R via the inhibition of the TLR2,4/MYD88/NFκB pathway, mediating anti-inflammation and activation of the Nrf2 pathway, intervening in antioxidative activities.

Pyracantha fortuneana (Maxim.) Li: A comprehensive review of its phytochemistry, pharmacological properties, and product development

Pyracantha fortuneana (Maxim.) Li has been used as a herbal medicine in China in its long history. Since ancient times, the fruits of P. fortuneana has been considered a functional food to improve various diseases. Many bioactive substances, including proanthocyanidins, phenols, polysaccharides, and dietary fibers, have been isolated and identified from the P. fortuneana, which possess diverse biological properties both in vitro and in vivo. Although the researches on the P. fortuneana have achieved extensive progress, the systematic study of its biological activities is still relatively lacking. In addition, accumulating researches focus on the landscape value of the P. fortuneana and the development of its by-products. The by-products of P. fortuneana, which show good development potentials in the field of agricultural production and environmental protection, are important for improving the economic value of P. fortuneana and its significance. After extensive reviewing and analyzing the existing published articles, books, and patents, this study aims to a systematic and summarized research trends of P. fortuneana and its phytochemical compositions, nutritional values, pharmacological effects and health benefits of its extracts/monomers, which would be beneficial for the future development of this medicinal plant as functional food or drugs.

Reno-protective effect of mangiferin against methotrexate-induced kidney damage in male rats: PPARγ-mediated antioxidant activity

Methotrexate (MTX) is an immunosuppressant used for the treatment of cancer and autoimmune diseases. MTX has a major adverse effect, acute kidney injury, which limits its use. Mangiferin (MF) is a natural bioactive xanthonoid used as a traditional herbal supplement to boost the immune system due to its potent anti-inflammatory and antioxidant activity. The present study evaluates the protective effect of MF against MTX-induced kidney damage. Male Wistar rats received MTX to induce nephrotoxicity or were pretreated with MF for 10 constitutive days before MTX administration. MF dose-dependently improved renal functions of MTX-treated rats and this activity was correlated with increased renal expression of PPARγ, a well-known transcriptional regulator of the immune response. Pretreating rats with PPARγ inhibitor, BADGE, reduced the reno-protective activity of MF. Furthermore, MF treatment significantly reduced MTX-induced upregulation of the pro-inflammatory (NFκB, interleukin-1ß, TNF-α, and COX-2), oxidative stress (Nrf-2, hemoxygenase-1, glutathione, and malondialdehyde), and nitrosative stress (nitric oxide and iNOS) markers in the kidney. Importantly, BADGE treatment significantly reduced the anti-inflammatory and antioxidant activity of MF. Therefore, our data suggest that the reno-protective effect of MF against MTX-induced nephrotoxicity is due to inhibition of inflammation and oxidative stress in a PPAR-γ-dependent manner.

Geraniol Ameliorates Doxorubicin-Mediated Kidney Injury through Alteration of Antioxidant Status, Inflammation, and Apoptosis: Potential Roles of NF-κB and Nrf2/Ho-1

Doxorubicin-mediated kidney impairment is a serious problem in cancer treatment. Accordingly, this work investigated the ability of geraniol to modulate doxorubicin-induced kidney damage using a rat model. Rats were randomly assigned to four groups: control, doxorubicin (20 mg/kg, intraperitoneal, i.p.), doxorubicin plus 100 mg/kg of geraniol, and doxorubicin plus 200 mg/kg of geraniol. A single doxorubicin injection triggered kidney impairment, as evidenced by the altered serum creatinine, blood urea nitrogen, and albumin values; it also caused histological changes in the kidney architecture. Additionally, doxorubicin enhanced lipid peroxidation while lowering reduced glutathione, catalase activity, and the expression of glutathione peroxidase and superoxide dismutase. Interestingly, pre-treatment with geraniol rescued doxorubicin-induced alterations in kidney antioxidant parameters, enzymatic activity, and the expression of inflammatory and apoptosis-mediating gene and proteins. Moreover, prophylactic treatment with geraniol preserved most kidney histological characteristics in a dose-dependent manner. These findings support that geraniol could protect against doxorubicin-mediated kidney dysfunction. However, further research is needed to clarify the mechanisms of geraniol’s protective effects against doxorubicin-mediated kidney dysfunction.

Geraniol protects against cyclosporine A-induced renal injury in rats: Role of Wnt/β-catenin and PPARγ signaling pathways

AIMS

The nephrotoxicity of cyclosporine A (CsA) limits its use as an immunosuppressant. Wnt/β-catenin signaling is involved in the pathogenesis of both acute and chronic kidney disease, and it is inhibited by peroxisome proliferator-activated receptor gamma (PPARγ). We aimed to evaluate if geraniol, which can modulate both PPARγ and Wnt signaling, could protect against CsA-induced nephrotoxicity.

MATERIALS AND METHODS

Rats (6 groups) received the vehicle or a combination of CsA (30 mg/kg) with the vehicle, geraniol (50, 100, or 200 mg/kg), or the PPARγ agonist pioglitazone for 4 weeks. Blood pressure (BP), markers of renal injury (serum urea, serum creatinine, blood urea nitrogen, and urinary NAG), oxidative stress (glutathione peroxidase), inflammation (ICAM-1, IL-18, and NF-κB), apoptosis (caspase-3), extracellular matrix remodeling [matrix metalloproteinase-9 (MMP-9)], and fibrosis (TGF-β1, Smad3, and Smad7) were assessed. Renal histological analysis, Wnt signaling components (Wnt-4/β-catenin and E-cadherin), and PPARγ expression were evaluated.

KEY FINDINGS

CsA group had renal injury, as well as increased BP, renal oxidative stress, inflammation, and fibrosis. The latter changes were associated with altered renal architecture, active Wnt signaling (higher Wnt-4 and β-catenin expression and E-cadherin down-regulation), and lower PPARγ levels. Geraniol protected against kidney damage and the associated biochemical and histomorphological changes in a dose-dependent manner. The latter effects were comparable or superior to those of pioglitazone.

SIGNIFICANCE

The down-regulation of Wnt/β-catenin and the increase in PPARγ by geraniol suggest that both pathways are involved in its renoprotective potential. The study highlights geraniol as a valuable protective asset against chemically induced nephrotoxicity.