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

Lipid nanoparticle-encapsulated lncRNA DLX6-AS1 knockdown ameliorates cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis

OBJECTIVE

Cerebral ischemia is a neurological disorder that leads to permanent disability. This research focuses on exploring the ameliorative effects of lipid nanoparticle (LNP)-encapsulated lncRNA DLX6-AS1 knockdown in cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis.

METHODS

LNP-encapsulated lncRNA DLX6-AS1 was prepared. Cerebral ischemic injury mouse models were established utilizing middle cerebral artery occlusion (MCAO). The mice were treated by intravenous injection of LNP-encapsulated lncRNA DLX6-AS1. The neurological deficits, Inflammatory factor levels, pathological characteristics were observed. In vitro N2a cell oxygen and glucose deprivation (OGD) models were established, and the cells were treated with LNP-encapsulated lncRNA DLX6-AS1 or Nrf2 inhibitor (ML385). Cell viability and apoptosis were tested. DLX6-AS1, Nrf2, HO-1, and NLRP3 expression levels were assessed.

RESULTS

LncRNA DLX6-AS1 levels were elevated in the brain tissues of mice with cerebral ischemic injury and OGD-induced N2a cells. LNP-encapsulated DLX6-AS1 siRNA (si-DLX6-AS1) improved neurological deficit scores, reduced the levels of inflammatory factors, improved brain tissue pathological damage, and raised the number of survival neurons in CA1. LNP-encapsulated si-DLX6-AS1 ameliorated the OGD-induced N2a cell viability decrease and apoptosis rate increase, and ML385 (Nrf2 inhibitor) reversed the ameliorative effects of LNP-encapsulated si-DLX6-AS1. In cerebral ischemic injury mice and OGD-induced N2a cells, Nrf2 and HO-1 levels were reduced and NLRP3 levels were increased. LNP-encapsulated si-DLX6-AS1 raised Nrf2 and HO-1 levels and reduced NLRP3 levels. Nrf2 inhibitor ML385 treatment reversed the ameliorative effects of LNP-encapsulated si-DLX6-AS1 on OGD-induced N2a cell viability and apoptosis.

CONCLUSION

Lipid nanoparticle-encapsulated si-DLX6-AS1 ameliorates cerebral ischemic injury via the Nrf2/HO-1/NLRP3 axis.

Potential mechanisms of formononetin against inflammation and oxidative stress: a review

Formononetin (FMNT) is a secondary metabolite of flavonoids abundant in legumes and graminaceous plants such as Astragalus mongholicus Bunge [Fabaceae; Astragali radix] and Avena sativa L. [Poaceae]. Astragalus is traditionally used in Asia countries such as China, Korea and Mongolia to treat inflammatory diseases, immune disorders and cancers. In recent years, inflammation and oxidative stress have been found to be associated with many diseases. A large number of pharmacological studies have shown that FMNT, an important bioactive metabolite of Astragalus, has a profoundly anti-inflammatory and antioxidant potential. This review focuses on providing comprehensive and up-to-date findings on the efficacy of the molecular targets and mechanisms involve of FMNT and its derivatives against inflammation and oxidative stress in both in vitro and in vivo. Relevant literature on FMNT against inflammation and oxidative stress between 2013 and 2023 were analyzed. FMNT has antioxidant and anti-inflammatory potential and shows mild or no toxicity in various diseases. Moreover, in the medical field, FMNT has shown potential in the prevention and treatment of cancers, neurological diseases, fibrotic diseases, allergic diseases, metabolic diseases, cardiovascular diseases, gastrointestinal diseases and autoimmune diseases. Thus, it is expected to be utilized in more products in the medical, food and cosmetic industries in the future.

Eucalyptol regulates Nrf2 and NF-kB signaling and alleviates gentamicin-induced kidney injury in rats by downregulating oxidative stress, oxidative DNA damage, inflammation, and apoptosis

Gentamicin, an aminoglycoside antibiotic, is nowadays widely used in the treatment of gram-negative microorganisms. The antimicrobial, anti-inflammatory, and antioxidant activities of eucalyptol, a type of saturated monoterpene, have been reported in many studies. The aim of this study was to examine the possible effects of eucalyptol on gentamicin-induced renal toxicity. A total of 32 rats were divided into 4 groups; Control (C), Eucalyptol (EUC), Gentamicin (GEN), and Gentamicin + Eucalyptol (GEN + EUC). In order to induce renal toxicity, 100 mg/kg gentamicin was administered intraperitoneally (i.p.) for 10 consecutive days in the GEN and GEN + EUC groups. EUC and GEN + EUC groups were given 100 mg/kg orally of eucalyptol for 10 consecutive days. Afterwards, rats were euthanized and samples were taken and subjected to histopathological, biochemical, immunohistochemical, and real-time PCR examinations. The blood urea nitrogen (BUN) and creatinine (CRE) levels were significantly decreased in the GEN + EUC group (0.76 and 0.69-fold, respectively) compared to the GEN group. The glutathione peroxidase (GPx) and catalase (CAT) activities were significantly increased in the GEN + EUC group (1.35 and 2.67-fold, respectively) compared to the GEN group. In GEN group, Nuclear factor kappa B (NF-kB), Interleukin 1-beta (IL-1β), Inducible nitric oxide synthase (iNOS), Tumor necrosis factor-α (TNF-α), Caspase-3, 8-Hydroxy-2'-deoxyguanosine (8-OHdG) and Nuclear factor erythroid 2-related factor (Nrf2) expression levels were found to be quite irregular. GEN + EUC group decreased the expressions of NF-kB, IL-1β, iNOS, TNF-α, Caspase-3, and 8-OHdG (0.55, 0.67, 0.54, 0.54, 0.63 and 0.67-fold, respectively), while it caused increased expression of Nrf2 (3.1 fold). In addition, eucalyptol treatment ameliorated the histopathological changes that occurred with gentamicin. The results of our study show that eucalyptol has anti-inflammatory, antioxidative, antiapoptotic, nephroprotective, and curative effects on gentamicin-induced nephrotoxicity.

Unveiling the Potential of Natural Compounds: A Comprehensive Review on Adipose Thermogenesis Modulation

The process of adipocyte browning has recently emerged as a novel therapeutic target for combating obesity and obesity-related diseases. Non-shivering thermogenesis is the process of biological heat production in mammals and is primarily mediated via brown adipose tissue (BAT). The recruitment and activation of BAT can be induced through chemical drugs and nutrients, with subsequent beneficial health effects through the utilization of carbohydrates and fats to generate heat to maintain body temperature. However, since potent drugs may show adverse side effects, nutritional or natural substances could be safe and effective as potential adipocyte browning agents. This review aims to provide an extensive overview of the natural food compounds that have been shown to activate brown adipocytes in humans, animals, and in cultured cells. In addition, some key genetic and molecular targets and the mechanisms of action of these natural compounds reported to have therapeutic potential to combat obesity are discussed.

Nrf2 knockout attenuates the astragaloside IV therapeutic effect on kidney fibrosis from liver cancer by regulating pSmad3C/3L pathways

Fibrotic kidney injury from hepatocarcinogenesis seriously impacts treatment effect. Astragaloside IV (AS-IV), an extract of Astragalus membranaceus, has several pharmacological activities, which are useful in the treatment of edema and fibrosis. Nrf2/HO-1 is a key antioxidant stress pathway and help treatment of kidney injury. Smad3 phosphorylation is implicated in hepatocarcinogenesis. Our previous study clarified that Smad3 is differentially regulated by different phosphorylated forms of Smad3 on hepatocarcinogenesis. Therefore, we investigated the contribution of AS-IV on the therapy of kidney fibrosis from hepatocarcinogenesis. And the focus was on whether the phosphorylation of Smad3 and the regulation of Nrf2/HO-1 pathway were involved during AS-IV therapy and whether there is an effect of Nrf2 knockout on the phosphorylation of Smad3. We performed TGF-β1 stimulation on HK-2 cells and intervened with AS-IV. Furtherly, we investigated renal injury of AS-IV on Nrf2 knockout mice during hepatocarcinogenesis and its mechanism of action. On the one hand, in vitro results showed that AS-IV reduced the ROS and α-SMA expression of HK-2 by promoting the expression pSmad3C/p21 of and Nrf2/HO-1 and suppressed the expression of pSmad3L/PAI-1. On the other hand, the in vivo results of histopathological features, serological biomarkers, and oxidative damage indicators showed that Nrf2 knockout aggravated renal injury. Besides, Nrf2 deletion decreased the nephroprotective effect of AS-IV by suppressing the pSmad3C/p21 pathway and promoting the pSmad3L/PAI-1 pathway. The experimental results were as we suspected. And we identify for the first time that Nrf2 deficiency increases renal fibrosis from hepatocarcinogenesis and attenuates the therapeutic effects of AS-IV via regulating pSmad3C/3L signal pathway.

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.

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.

Enhancing Anticancer Efficacy of Formononetin Microspheres via Microfluidic Fabrication

Formononetin is a flavonoid compound with anti-tumor and anti-inflammatory properties. However, its low solubility limits its clinical use. We employed microfluidic technology to prepare formononetin-loaded PLGA-PEGDA microspheres (Degradable polymer PLGA, Crosslinking agent PEGDA), which can encapsulate and release drugs in a controlled manner. We optimized and characterized the microspheres, and evaluated their antitumor effects. The microspheres had uniform size, high drug loading efficiency, high encapsulation efficiency, and stable release for 35 days. They also inhibited the proliferation, migration, and apoptosis. The antitumor mechanism involved the induction of reactive oxygen species and modulation of Bcl-2 family proteins. These findings suggested that formononetin-loaded PLGA-PEGDA microspheres, created using microfluidic technology, could be a novel drug delivery system that can overcome the limitations of formononetin and enhance its antitumor activity.

Shenshuaifu Granule Attenuates Acute Kidney Injury by Inhibiting Ferroptosis Mediated by p53/SLC7A11/GPX4 Pathway

Background

Acute kidney injury (AKI) is a common clinical condition resulting in a rapid decline in renal function, and requires improvement in effective preventive measures. Ferroptosis, a novel form of cell death, is closely related to AKI. Shenshuaifu granule (SSF) has been demonstrated to prevent AKI through suppressing inflammation and apoptosis.

Objective

This study aimed to explore whether SSF can inhibit ferroptosis in AKI.

Methods

Active ingredients in SSF were detected through HPLC-MS/MS, and their binding abilities with ferroptosis were evaluated by molecular docking. Then, male C57/BL/6J mice were randomly divided into control, cisplatin, and cisplatin+SSF groups. In the latter two groups, mice were intraperitoneally injected with 20 mg/kg of cisplatin. For five consecutive days prior to cisplatin injection, mice in the cisplatin+SSF group were gavaged with 5.2 g/kg of SSF per day.72 h after cisplatin injection, the mice were sacrificed. Serum creatinine (SCr) and blood urea nitrogen (BUN) were measured to evaluate renal function. H&E and PAS staining were used to observe pathological damage of kidney. Cell death was observed by TUNEL staining, and iron accumulation in kidneys of mice was detected by Prussian blue staining. Western blotting, immunohistochemistry, and immunofluorescence were used to investigate the presence of inflammation, oxidative stress, mitochondrial dysfunction, iron deposition, and lipid peroxidation in mouse kidneys.

Results

Active ingredients in SSF had strong affinities with ferroptosis. SSF reduced SCr (p<0.01) and BUN (p<0.0001) levels, pathological damage (p<0.0001), dead cells in the tubular epithelium (p<0.0001) and iron deposition (p<0.01) in mice with cisplatin induced AKI. And SSF downregulated macrophage infiltration (p<0.01), the expressions of high mobility group box 1 (HMGB1, p<0.05) and interleukin (IL)-17 (p<0.05), upregulated superoxide dismutase (SOD) 1 and 2 (p<0.01), and catalase (CAT, p<0.05), and alleviated mitochondrial dysfunction (p<0.05). More importantly, SSF regulated iron transport and intracellular iron overload and reduced the expression of ferritin (p<0.05). Moreover, it downregulated the expressions of cyclo-oxygenase-2 (Cox-2, p<0.001), acid CoA ligase 4 (ACSL4, p<0.05), and solute carrier family 7, member 11 (SLC7A11, p<001), upregulated glutathione peroxidase 4 (GPX4, p<0.01) and p53 (p<0.01), and decreased 4-hydroxynonenal (4-HNE) level (p<0.001).

Conclusion

SSF attenuates AKI by inhibiting ferroptosis mediated by p53/SLC7A11/GPX4 pathway.

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.

Zinc and L-carnitine combination with or without methotrexate prevents intestinal toxicity during arthritis treatment via Nrf2/Sirt1/Foxo3 pathways: an In vivo and molecular docking approach

Methotrexate (MTX) is an antifolate that is inescapable and widely used to treat autoimmune diseases and is the gold standard medicine for the arthritic condition. Despite its importance, it is more prone to gastrointestinal toxicity, which is most common in arthritis patients during MTX treatment. Combination therapies are required to ensure MTX's antiarthritic activity while providing gastrointestinal protection. Zinc (Zn) and L-carnitine (Lc) are well-known potent antioxidants and anti-inflammatory supplements with promising results in pre-clinical studies. Arthritis was induced in Wistar rat's ankles with Freund's adjuvant and treated with either MTX (2.5 mg/kg b.w per week for two weeks) or Zn (18 mg/kg b.w. per day) Lc (200 mg/kg b.w. per day) individually or in combination (MTX + Zn Lc). The antiarthritic effects were evaluated by body weight, paw volume, ankle tissue, and joint histopathology. At the same time, anti-toxicity/gastrointestinal protective activity was examined by tissue oxidative stress markers, antioxidants, mitochondrial function, inflammatory mediators, and antioxidant signaling proteins and their binding mechanism. Repercussions of MTX intoxication induced upregulation of oxidative stress markers, antioxidant depletion, ATP depletion, decreased expression of Nrf2/Sirt1/Foxo3, and the overexpression of inflammatory mediators attenuated by co-treatment with Zn Lc. Zn Lc markedly mitigated MTX-instigated intestinal injury by activating antioxidant signaling mechanisms Nrf2/Sirt1/Foxo3 signaling and tissue architectural anomalies and exhibited an enhanced antiarthritic effect. In conclusion, we report that Zn Lc and MTX combination could presumably protect the intestine from low-dose MTX which managed arthritis but induced severe intestinal damage with increased inflammation and downregulated Nrf2/Sirt1/Foxo3 pathway.

Echinochrome A Prevents Diabetic Nephropathy by Inhibiting the PKC-Iota Pathway and Enhancing Renal Mitochondrial Function in db/db Mice

Echinochrome A (EchA) is a natural bioproduct extracted from sea urchins, and is an active component of the clinical drug, Histochrome®. EchA has antioxidant, anti-inflammatory, and antimicrobial effects. However, its effects on diabetic nephropathy (DN) remain poorly understood. In the present study, seven-week-old diabetic and obese db/db mice were injected with Histochrome (0.3 mL/kg/day; EchA equivalent of 3 mg/kg/day) intraperitoneally for 12 weeks, while db/db control mice and wild-type (WT) mice received an equal amount of sterile 0.9% saline. EchA improved glucose tolerance and reduced blood urea nitrogen (BUN) and serum creatinine levels but did not affect body weight. In addition, EchA decreased renal malondialdehyde (MDA) and lipid hydroperoxide levels, and increased ATP production. Histologically, EchA treatment ameliorated renal fibrosis. Mechanistically, EchA suppressed oxidative stress and fibrosis by inhibiting protein kinase C-iota (PKCι)/p38 mitogen-activated protein kinase (MAPK), downregulating p53 and c-Jun phosphorylation, attenuating NADPH oxidase 4 (NOX4), and transforming growth factor-beta 1 (TGFβ1) signaling. Moreover, EchA enhanced AMPK phosphorylation and nuclear factor erythroid-2-related factor 2 (NRF2)/heme oxygenase 1 (HO-1) signaling, improving mitochondrial function and antioxidant activity. Collectively, these findings demonstrate that EchA prevents DN by inhibiting PKCι/p38 MAPK and upregulating the AMPKα/NRF2/HO-1 signaling pathways in db/db mice, and may provide a therapeutic option for DN.

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.

Natural products for kidney disease treatment: Focus on targeting mitochondrial dysfunction

The patients with kidney diseases are increasing rapidly all over the world. With the rich abundance of mitochondria, kidney is an organ with a high consumption of energy. Hence, renal failure is highly correlated with the breakup of mitochondrial homeostasis. However, the potential drugs targeting mitochondrial dysfunction are still in mystery. The natural products have the superiorities to explore the potential drugs regulating energy metabolism. However, their roles in targeting mitochondrial dysfunction in kidney diseases have not been extensively reviewed. Herein, we reviewed a series of natural products targeting mitochondrial oxidative stress, mitochondrial biogenesis, mitophagy, and mitochondrial dynamics. We found lots of them with great medicinal values in kidney disease. Our review provides a wide prospect for seeking the effective drugs targeting kidney diseases.

Ramelteon and mechanism of its restorative effect in an experimental lung disease model

Methotrexate (MTX) is an anticancer agent widely used in clinical practice for various oncological, rheumatological, autoimmune, and inflammatory diseases. However, the side effects of MTX limit its usage for treatment. In addition, diffuse alveolar damage, interstitial pneumonia, fibrosis, and pleural reactions may be encountered in MTX-induced pulmonary toxicity. Ramelteon (RML), a melatonin receptor agonist, has antioxidant, anti-inflammatory, and protective effects are shown by several studies. This study aimed to show the antioxidant, anti-inflammatory, and antiapoptotic effects of RML and its effect on the airway surface liquid volume homeostasis via aquaporins (AQP) in MTX-induced lung injury. Thirty-two female Wistar Albino rats were grouped into four groups as control, MTX (20 mg/kg, intraperitoneally, a single dose), MTX + RML, and RML (10 mg/kg, via oral gavage, for seven days) groups. Once the experiment ended, the rats' lung tissues were taken for biochemical, genetic, histopathological, and immunohistochemical examinations. MTX significantly increased oxidative stress index and total oxidative status, and decreased total antioxidant status levels by 202.0%, 141.4%, 20.2%, respectively, relative to the control (p ˂ 0.001 for all). AQP-1/5, which is an indicator of lung damage, was also found to decrease significantly (p ˂ 0.001). In addition, a significant increase was observed in interleukin-1β, interferon-beta, and caspase-8 expressions and histopathological changes as a result of immunohistochemical and histochemical examinations (p ˂ 0.001). RML treatment ameliorated all these changes and significantly regressed lung damage. Our results suggest that RML might be used as a lung-protective agent in various models of lung and tissue injury.

Empagliflozin mitigates methotrexate-induced hepatotoxicity: Targeting ASK-1/JNK/Caspase-3 pathway

Methotrexate (MTX) administration causes hepatotoxicity, a serious side effect limiting its clinical use. Therefore, this study was performed to investigate the beneficial effect of empagliflozin (Empa) against MTX-induced hepatotoxicity. Adult male albino mice were pre-treated with Empa (at 10 or 25 mg/kg/d, orally) for 6 days and then received a single MTX injection (at 20 mg/kg, intraperitoneally). Empa effectively ameliorated MTX-induced structural and functional alterations. It significantly decreased transaminase, alkaline phosphatase, and gamma-glutamyl transferase levels and increased albumin levels in the serum. Moreover, Empa restored the oxidant/antioxidant balance as indicated by reduced malondialdehyde and total nitrite/nitrate contents and elevated reduced glutathione level and superoxide dismutase activity. Additionally, Empa (10 and 25 mg/kg) markedly suppressed the elevated levels of tumor necrosis factor-alpha, interleukin-6, apoptosis signal-regulating kinase1, c-Jun N-terminal kinase, BCL2 associated X protein, and Caspase-3 in hepatic tissues and increased the hepatic interleukin-10 levels. Furthermore, Empa substantially decreased nuclear factor kappa B expression in hepatic tissues. These biochemical findings were further confirmed by histopathological and transmission electron microscopy observations. Therefore, Empa might be used as an adjuvant to ameliorate MTX-induced hepatotoxicity after further clinical evaluation.

Taxifolin Prevents Cisplatin Nephrotoxicity by Modulating Nrf2/HO-1 Pathway and Mitigating Oxidative Stress and Inflammation in Mice

Cisplatin (CIS) is an effective chemotherapeutic agent used in the treatment of several malignancies. The clinical use of CIS is associated with adverse effects, including acute kidney injury (AKI). Oxidative stress and inflammation are key events in the development of CIS-induced AKI. This study investigated the protective effect of taxifolin (TAX), a bioactive flavonoid with promising health-promoting properties, on CIS-induced nephrotoxicity in mice. TAX was orally given to mice for 10 days and a single dose of CIS was injected at day 7. Serum blood urea nitrogen (BUN) and creatinine were elevated, and multiple histopathological alterations were observed in the kidney of CIS-administered mice. CIS increased renal malondialdehyde (MDA), nitric oxide (NO), nuclear factor-kappaB (NF-κB) p65, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β, and decreased cellular antioxidants in mice. TAX remarkably prevented kidney injury, ameliorated serum BUN and creatinine, and renal MDA, NO, NF-κB p65, and pro-inflammatory cytokines, and boosted antioxidant defenses in CIS-administered mice. TAX downregulated Bax and caspase-3, and upregulated Bcl-2. These effects were associated with upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) expression and heme oxygenase (HO)-1 activity in CIS-administered mice. In conclusion, TAX prevented CIS-induced AKI by mitigating tissue injury, oxidative stress, inflammation, and cell death. The protective efficacy of TAX was associated with the upregulation of Nrf2/HO-1 signaling.

The Protective Effects of Nutraceutical Components in Methotrexate-Induced Toxicity Models—An Overview

There are multiple concerns associated with methotrexate (MTX), widely recognized for anti-neoplastic and anti-inflammatory effects in life-threatening disease conditions, i.e., acute lymphoblastic leukemia, non-Hodgkin’s lymphoma, psoriasis, and rheumatoid arthritis, due to long-term side effects and associated toxicity, which limits its valuable potential. MTX acts as an inhibitor of dihydrofolate reductase, leading to suppression of purine and pyrimidine synthesis in high metabolic and turnover cells, targeting cancer and dysregulated immune cells. Due to low discrimination between neoplastic cells and naturally high turnover cells, MTX is prone to inhibiting the division of all fast-dividing cells, causing toxicity in multiple organs. Nutraceutical compounds are plant-based or food-derived compounds, used for their preventive and therapeutic role, ascertained in multiple organ dysfunctions, including cardiovascular disease, ischemic stroke, cancer, and neurodegenerative diseases. Gut microbiota and microbiota-derived metabolites take part in multiple physiological processes, their dysregulation being involved in disease pathogenesis. Modulation of gut microbiota by using nutraceutical compounds represents a promising therapeutic direction to restore intestinal dysfunction associated with MTX treatment. In this review, we address the main organ dysfunctions induced by MTX treatment, and modulations of them by using nutraceutical compounds. Moreover, we revealed the protective mechanisms of nutraceuticals in MTX-induced intestinal dysfunctions by modulation of gut microbiota.

The Protective Effect of Ursolic Acid on Unilateral Ureteral Obstruction in Rats by Activating the Nrf2/HO-1 Antioxidant Signaling Pathway

Renal interstitial fibrosis is a common pathological feature of a variety of kidney diseases that progress to end-stage renal disease. The excessive deposition of extracellular matrix (ECM) is a typical pathological change of renal interstitial fibrosis. The production of reactive oxygen species in renal tubules is an important factor leading to the development of renal interstitial fibrosis. Ursolic acid (UA) is a natural pentacyclic triterpene carboxylic acid compound widely found in plants. It has anti-inflammatory, antioxidant, and antitumor cell proliferation effects. It can reduce the development of fibrosis by inhibiting the oxidative stress response of the liver; there is currently no relevant research on whether UA can protect the renal interstitial fibrosis by resisting oxidative stress in the kidneys. In this study, our purpose is to investigate the effect of ursolic acid on renal interstitial fibrosis after unilateral ureteral obstruction (UUO) in rats and its related mechanisms. We established a UUO model by surgically ligating the right ureter of the rat and instilling UA preparation (40 mg/kg/d) through the stomach after the operation, once a day for 7 days. We found that UUO caused impaired renal function, increased pathological damage, increased renal interstitial fibrosis, increased apoptosis, increased oxidative stress damage, and decreased antioxidants. However, after UA preparations were given, the abovementioned damage was significantly improved. At the same time, we also found that UA preparations can significantly increase the relative expression of Nrf2/HO-1 signaling pathway in kidney tissue after UUO. In order to further verify whether the Nrf2/HO-1 signaling pathway is involved in the development of renal interstitial fibrosis, we injected zinc protoporphyrin (ZnPP, 45 umol/kg), a specific blocker of the Nrf2/HO-1 signaling pathway, into the intraperitoneal cavity after UUO in rats and before the gastric perfusion of ursolic acid preparations. Subsequently, we observed that the protective effect of UA on renal interstitial fibrosis after UUO in rats was reversed. Combining all the research results, we proved that UA has a protective effect on renal interstitial fibrosis after UUO in rats, which may be achieved by activating the Nrf2/HO-1 signaling pathway.

Renoprotective and Oxidative Stress-Modulating Effects of Taxifolin against Cadmium-Induced Nephrotoxicity in Mice

Cadmium (Cd) is an inessential trace metal that accumulates in the kidney and may lead to renal toxicity by mediating oxidative stress (OS), inflammatory reactions, and apoptosis. The main objective of this experiment was to inspect the protecting potential of taxifolin (TA) on Cd-induced renal toxicity. Adult male mice were allocated into equal five groups as follows: control, TA-treated (50 mg/kg, oral), CdCl₂-treated (4 mg/kg body weight (BW), p.o.), pretreated with TA (25 mg/kg) 1 h before CdCl₂ injection (4 mg/kg BW, p.o.), and pretreated with TA (50 mg/kg) 1 h before CdCl₂ injection (4 mg/kg BW, p.o.) for 14 days. Cd-intoxicated mice revealed higher serum urea and creatinine levels and notable histopathological alterations in the renal tissues. Malondialdehyde (MDA), nitric oxide (NO), nuclear factor-kappa B (NF-κB) p65, tumor necrosis factor-α (TNF-α), and IL-1β were increased. In contrast, glutathione levels, catalase and superoxide dismutase activities, and IL-10 levels were decreased under Cd-administered effects. Conversely, the TA pre-treatment highly protected tissues from Cd-toxicity, improved renal function, decreased MDA and NO levels, attenuated inflammation, and improved redox status in the renal tissues of Cd-intoxicated mice. The TA pre-treatment of Cd-intoxicated mice showed down-regulation of both Bax and caspase-3 protein and up-regulation of Bcl-2 protein expression in the kidney. Furthermore, TA pre-treatment induced higher upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) expression in kidney cells of Cd-intoxicated mice. Therefore, TA can protect renal tissues against Cd-induced nephrotoxicity via improving redox status, modulating inflammation, diminishing cell apoptosis, and activating the Nrf2/HO-1 signaling pathway.

Protective effect of Astragalus membranaceus and Astragaloside IV in sepsis-induced acute kidney injury

Background: Acute kidney injury (AKI) is the most common target organ damage in sepsis. Sepsis-associated AKI (SA-AKI) may be characterized by damage to the renal tubular epithelium. In this study, the pharmacological mechanisms of Astragalus membranaceus and its active monomer Astragaloside IV (AS-IV) were predicted based on a network pharmacology approach and validated both in vitro and in vivo using the SA-AKI model.

Method: We constructed an in vivo sepsis model using a mouse cecum ligation puncture (CLP) and HK-2 cells were treated with lipopolysaccharide (LPS) to mimic Gram (–) induced sepsis to assess the renal-protective efficacy of Astragalus membranaceus and AS-IV.

Results: The findings demonstrated that Astragalus membranaceus and AS-IV attenuate renal tubular injury in mice with polymicrobial sepsis, including vacuolization, loss of brush border, mitochondrial ultrastructural changes, and increased staining of kidney injury molecule-1 (KIM-1). AS-IV protected human proximal tubular epithelial (HK-2) cells against LPS induced cell viability loss. Both Astragalus membranaceus and AS-IV activated the PI3K/AKT pathway both in vitro and in vivo, as shown by Western blot and immunohistochemistry analysis.

Conclusion: The findings demonstrate that Astragalus membranaceus and AS-IV protect against sepsis-induced kidney tubular injury by activating the PI3K/AKT pathway.

Lutein Can Alleviate Oxidative Stress, Inflammation, and Apoptosis Induced by Excessive Alcohol to Ameliorate Reproductive Damage in Male Rats

Chronic excessive alcohol intake may lead to male reproductive damage. Lutein is a carotenoid compound with antioxidant activity. The purpose of this study was to observe the effect of lutein supplementation on male reproductive damage caused by excessive alcohol intake. In this study, an animal model of excessive drinking (12 mL/(kg.bw.d)) for 12 weeks was established and supplemented with different doses of lutein (12, 24, 48 mg/(kg.bw.d)). The results showed that the body weight, sperm quality, sex hormones (FSH, testosterone), and antioxidant markers (GSH-Px) decreased significantly, while MDA and inflammatory factors (IL-6, TNF-α) increased significantly in the alcohol model group when compared to the normal control group. After 12 weeks of high-dose lutein supplementation with 48mg/(kg.bw.d), the spermatogenic ability, testosterone level, and the activity of marker enzymes reflecting testicular injury were improved. In addition, high-dose lutein supplementation downregulated the NF-κB and the pro-apoptosis biomarkers (Bax, Cytc and caspase-3), whereas it upregulated the expression of Nrf2/HO-1 and the anti-apoptotic molecule Bcl-2. These findings were fully supported by analyzing the testicular histopathology and by measuring germ cell apoptosis. In conclusion, lutein protects against reproductive injury induced by excessive alcohol through its antioxidant, anti-inflammatory, and anti-apoptotic properties.

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 Improves the Survival of Random Skin Flaps Through PI3K/Akt-Mediated Nrf2 Antioxidant Defense System

Random-pattern skin flap is widely used in plastic and reconstructive surgery. However, its clinical effect is limited by ischemia necrosis occurs at the distal part of flap. Previous studies have proved that the protective effect of formononetin was associated with its antioxidant, anti-inflammatory ability. However, further research is still needed on the effect of formononetin on flap viability. The purpose of our study was to investigate the effect of formononetin on flap survival and the underlying mechanisms. Two doses (25 mg/kg, 50 mg/kg)of formononetin were administered for seven consecutive days on flap model. Flap tissues were collected on postoperative day 7. Our results revealed that formononetin promoted skin flap viability in a dose-dependent manner. Using immunohistochemical staining and western blot, we found that formononetin significantly reduced oxidative stress and inflammation. Hematoxylin and eosin (H and E) staining, laser Doppler images and immunofluorescence staining showed the enhancement of angiogenesis after formononetin treatment. Mechanistically, we demonstrated that the antioxidation of formononetin was mediated by activation and nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2), while down-regulating cytoplasmic Kelch-like ECH-associated protein 1 (Keap1) expression. Co-treatment with formononetin and LY294002 (15 mg/kg), a potent Phosphatidylinositol-3-kinase (PI3K) inhibitor, which aborted nuclear Nrf2 expression and phosphorylated Akt, indicating that formononetin-mediated Nrf2 activation was related to PI3K/Akt pathway. Overall, our findings revealed that formononetin increased angiogenesis, reduced oxidative stress and inflammation, thus promoting flap survival. We highlighted the antioxidant effects of formononetin since the Nrf2 system was activated. Therefore, formononetin might be a promising candidate drug that can enhance survival of skin flaps.

Formononetin Attenuates Renal Tubular Injury and Mitochondrial Damage in Diabetic Nephropathy Partly via Regulating Sirt1/PGC-1α Pathway

Mitochondrial abnormality is one of the main factors of tubular injury in diabetic nephropathy (DN). Formononetin (FMN), a novel isoflavonoid isolated from Astragalus membranaceus, has diverse pharmacological activities. However, the beneficial effects of FMN on renal tubular impairment and mitochondrial dysfunction in DN have yet to be studied. In this study, we performed in vivo tests in Streptozotocin (STZ) -induced diabetic rats to explore the therapeutic effects of FMN on DN. We demonstrated that FMN could ameliorate albuminuria and renal histopathology. FMN attenuated renal tubular cells apoptosis, mitochondrial fragmentation and restored expression of mitochondrial dynamics-associated proteins, such as Drp1, Fis1 and Mfn2, as well as apoptosis-related proteins, such as Bax, Bcl-2 and cleaved-caspase-3. Moreover, FMN upregulated the protein expression of Sirt1 and PGC-1α in diabetic kidneys. In vitro studies further demonstrated that FMN could inhibit high glucose-induced apoptosis of HK-2 cells. FMN also reduced the production of mitochondrial superoxide and alleviated mitochondrial membrane potential (MMP) loss. Furthermore, FMN partially restored the protein expression of Drp1, Fis1 and Mfn2, Bax, Bcl-2, cleaved-caspase-3, Sirt1 and PGC-1α in HK-2 cells exposure to high glucose. In conclusion, FMN could attenuate renal tubular injury and mitochondrial damage in DN partly by regulating Sirt1/PGC-1α pathway.

Laminaria japonica fucoidan ameliorates cyclophosphamide-induced liver and kidney injury possibly by regulating Nrf2/HO-1 and TLR4/NF-κB signaling pathways

BACKGROUND

During clinical practice, cyclophosphamide (CTX) can lead to liver and kidney injury in vivo. In this study, we established a liver and kidney injury model by injecting CTX (80 mg kg-1  d-1 ) into male ICR mice, and then mice were treated with saline and fucoidan (20 or 40 mg kg-1 ), respectively. Subsequently, the liver and kidney toxicity indices, the expression levels of malonic dialdehyde (MDA), inflammatory factors, and the main protein levels of the Nrf2/HO-1 and TLR4/NF-κB pathways were determined.

RESULTS

Our results indicated that fucoidan could significantly decrease serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CRE), and urea (BUN) in the test group compared to the model group. Fucoidan administration caused reductions in MDA, interleukin-6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α) levels and improved superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities in the liver and kidney of CTX-induced mice. Fucoidan up-regulated the Nrf2/HO-1 pathway and enhanced the protein levels of Nrf2, HO-1, GCLM, and NQO1. Moreover, fucoidan down-regulated the TLR4/NF-κB pathway, as indicated by decreased levels of TLR4, NF-κB p65, NF-κB p50, and increased IκBα level in liver and kidney tissues.

CONCLUSION

Our studies suggest that fucoidan can ameliorate CTX-induced liver and kidney injury, potentially via up-regulating the Nrf2/HO-1 pathway and inhibiting the TLR4/NF-κB pathway. © 2021 Society of Chemical Industry.

Formononetin attenuates Aβ25-35-induced adhesion molecules in HBMECs via Nrf2 activation

Brain vascular inflammation plays a crucial role in the pathogenesis of Alzheimer's disease (AD). As a central pathogenic factor in AD, the extracellular buildup of amyloid-β (Aβ) induces brain microvascular endothelial cells activation, impairs endothelial structure and function. Formononetin (FMN) has been reported to protect against Alzheimer's disease (AD) and attenuates vascular inflammation in atherosclerosis. However, its involvement in regulating vascular inflammation of AD has not been investigated. In the study, we found that FMN significantly attenuates Aβ_25-35-induced expression of adhesion molecules, including intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the human brain microvascular endothelial cells (HBMECs), suggesting that FMN inhibits Aβ_25-35-induced brain endothelial cells inflammatory response. Moreover, we observed that FMN attenuates Aβ_25-35-induced translocation of NFκB (p65) into the nucleus of HBMECs, and found that FMN treatment induces Nrf2 expression and attenuates Nrf2-Keap1 association in a dose-dependent manner in HBMECs. Furthermore, we demonstrated that Nrf2 silencing significantly attenuates FMN-reduced NFκB (p65) activation and nuclear translocation. Lastly, our results showed that FMN treatment attenuates Aβ_25-35-induced adhesion of THP-1 cell to endothelial cell monolayer. Collectively, these findings suggest that FMN attenuates Aβ_25-35-induced activation in human brain microvascular endothelial cells, which at least in part was mediated through Nrf2 pathways.

Eugenol-Preconditioned Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Antioxidant Capacity of Tendon Stem Cells In Vitro and In Vivo

Tendon stem cells (TSCs) are often exposed to oxidative stress at tendon injury sites, which impairs their physiological effect as well as therapeutic application. Recently, extracellular vesicles (EVs) derived from bone marrow mesenchymal stem cells (BMSCs) were shown to mediate cell protection and survival under stress conditions. The function of BMSC-EVs may be affected by pretreatment with various factors such as eugenol (EUG)—a powerful antioxidant. In our previous study, we found that H₂O₂ significantly impaired TSC proliferation and tenogenic differentiation capabilities. Apoptosis and intracellular ROS accumulation in TSCs were induced by H₂O₂. However, such H₂O₂-induced damage was prevented by treatment with EUG-BMSC-EVs. Furthermore, EUG-BMSC-EVs activated the Nrf2/HO-1 pathway to counteract H₂O₂-induced damage in TSCs. In a rat patellar tendon injury model, the ROS level was significantly higher than that in the normal tendon and TSCs not pretreated showed a poor therapeutic effect. However, EUG-BMSC-EV-pretreated TSCs significantly improved tenogenesis and matrix regeneration during tendon healing. Additionally, the EUG-BMSC-EV group had a significantly improved fiber arrangement. Overall, EUG-BMSC-EVs protected TSCs against oxidative stress and enhanced their functions in tendon injury. These findings provide a basis for potential clinical use of EUG-BMSC-EVs as a new therapeutic vehicle to facilitate TSC therapies for tendon regeneration.

Paeonol Protects Against Methotrexate-Induced Nephrotoxicity via Upregulation of P-gp Expression and Inhibition of TLR4/NF-κB Pathway

Methotrexate (MTX) is a well-known anticancer drug that causes nephrotoxicity as a side effect. To investigate the mechanisms by which paeonol, a natural phenolic compound, can protect against MTX-induced nephrotoxicity, paeonol (100 mg/kg/day orally) was given to rats for 10 days, with or without MTX (20 mg/kg once i.p. at day 5). Compared to control, MTX caused nephrotoxic effects manifested by increased serum urea and creatinine and distortion in renal histological architecture, with a significant increase in the mean glomerular diameter and upregulation of kidney injury molecule-1. MTX caused oxidative stress manifested by decreasing reduced glutathione and superoxide dismutase while increasing malondialdehyde and nitric oxide. MTX also induced renal inflammation by upregulating TLR4, NF-κB, and IL-1β and caused apoptosis by induction of caspase 3. Administering paeonol with MTX improved kidney functional and structural parameters, as well as all oxidative, inflammatory, and apoptotic markers tested. Interestingly, both MTX and paeonol increased the expression of the renal efflux transporter P-glycoprotein (P-gp) that helps in MTX elimination, and their drug combination further upregulated renal P-gp. In silico, paeonol was neither a substrate nor an inhibitor of P-gp, suggesting that its effect on P-gp is not on functional but on the expression level. In vitro, paeonol and MTX were administered to colon cancer cells and their combination caused a progressive cellular cytotoxic effect, which was dose-dependent with the increase of paeonol concentration. In conclusion, paeonol protects against MTX-induced nephrotoxicity through antioxidant, anti-inflammatory, and antiapoptotic mechanisms and might potentiate MTX chemotherapeutic efficacy.

Dissecting the Crosstalk Between Nrf2 and NF-κB Response Pathways in Drug-Induced Toxicity

Nrf2 and NF-κB are important regulators of the response to oxidative stress and inflammation in the body. Previous pharmacological and genetic studies have confirmed crosstalk between the two. The deficiency of Nrf2 elevates the expression of NF-κB, leading to increased production of inflammatory factors, while NF-κB can affect the expression of downstream target genes by regulating the transcription and activity of Nrf2. At the same time, many therapeutic drug-induced organ toxicities, including hepatotoxicity, nephrotoxicity, cardiotoxicity, pulmonary toxicity, dermal toxicity, and neurotoxicity, have received increasing attention from researchers in clinical practice. Drug-induced organ injury can destroy body function, reduce the patients’ quality of life, and even threaten the lives of patients. Therefore, it is urgent to find protective drugs to ameliorate drug-induced injury. There is substantial evidence that protective medications can alleviate drug-induced organ toxicity by modulating both Nrf2 and NF-κB signaling pathways. Thus, it has become increasingly important to explore the crosstalk mechanism between Nrf2 and NF-κB in drug-induced toxicity. In this review, we summarize the potential molecular mechanisms of Nrf2 and NF-κB pathways and the important effects on adverse effects including toxic reactions and look forward to finding protective drugs that can target the crosstalk between the two.

Formononetin regulates endothelial nitric oxide synthase to protect vascular endothelium in deep vein thrombosis rats

OBJECTIVE

Formononetin is a bioactive isoflavone that has numerous medicinal benefits. We explored the feasibility and its mechanism of formononetin on treating acute deep vein thrombosis (DVT) in rats.

MATERIALS AND METHODS

Inferior vena cava (IVC) stenosis was performed to establish the DVT rat model. First, different doses of formononetin were used to observe the feasibility of formononetin on treating DVT. In sham and DVT groups, rats were orally treated with vehicle. In the remaining groups, formononetin (10 mg/kg, 20 mg/kg, and 40 mg/kg) was orally treated once a day for 7 days at 24 h after IVC. After 7 days, the levels of thrombosis and inflammation related factors in plasma were measured. The expression of endothelial nitric oxide synthase (eNOS) was analyzed by western blot and immunofluorescence. Molecular docking was used to evaluate the interaction between the formononetin and eNOS. Further, the NOS inhibitor (L-NAME) was used to explore the mechanism of formononetin for DVT.

RESULT

After treatment with formononetin, the average weights of thrombosis were decreased, and the levels of thrombosis and inflammation related factors were also significantly decreased. Additionally, phosphorylation of eNOS was increased with the formononetin administration. There is a good activity of formononetin to eNOS (total score = -6.8). However, the effects of 40 mg/kg formononetin were concealed by the NOS inhibitor (L-NAME).

CONCLUSION

Formononetin reduces vascular endothelium injury induced by DVT through increasing eNOS in rats, which provides a potential drug for treatment of venous thrombosis.

Targeting inflammation, autophagy, and apoptosis by troxerutin attenuates methotrexate-induced renal injury in rats

BACKGROUND

Troxerutin, a bioflavonoid with marked immune-modulatory and antioxidant features, has been proven to ameliorate experimental cardiotoxicity, hepatotoxicity, and neurodegeneration. However, its impact on methotrexate (MTX)-induced nephrotoxicity has not been investigated. In the current work, we aimed to investigate the potential of troxerutin to combat MTX-triggered renal injury, exploring immune cell infiltration, inflammation, autophagy, and apoptosis, with emphasis on the HMGB1/RAGE/NF-κB, AMPK/mTOR, and Nrf2/HO-1 pathways.

METHODOLOGY

Troxerutin (150 mg/kg/day) was administered by oral gavage and the renal tissues were examined with the aid of biochemical assays, ELISA, histology, and immunohistochemistry.

KEY FINDINGS

Troxerutin mitigated MTX-induced renal dysfunction by significantly lowering creatinine, BUN, and KIM-1 alongside immune-cell infiltration and histopathologic aberrations. These favorable effects were mediated by inhibition of HMGB1/RAGE/NF-κB cascade via downregulating the protein expression of HMGB1, RAGE, and nuclear NF-κBp65 alongside its downstream signals, including COX-2 and TNF-α. Moreover, troxerutin activated the autophagy flux as evidenced by upregulating renal Beclin 1, lowering p62 SQSTM1 accumulation, and activation of AMPK/mTOR pathway, seen by increasing p-AMPK/total AMPK and lowering p-mTOR/total mTOR signals. In tandem, troxerutin combated renal apoptotic changes as proven with lowering caspase-3 activity, Bax expression, and Bax/Bcl-2 ratio and upregulating the proliferation signal PCNA. Additionally, the oxidative insult was attenuated by troxerutin, as evidenced by lowering NOX-1 and lipid peroxides, replenishing GSH, GPx, and SOD antioxidants, and activating Nrf2/HO-1 pathway.

CONCLUSION

Troxerutin attenuated MTX-triggered renal injury via inhibition of inflammation and apoptosis alongside activation of autophagy. Thus, it may serve as an adjunct modality for the management of MTX-linked nephrotoxicity.

Effects of Long-Term Exposure to Copper on the Keap1/Nrf2 Signaling Pathway and Msr-Related Redox Status in the Kidneys of Rats

The objective of the present study was to examine the effects of long-term exposure on oxidative damage, Keap1/Nrf2 signaling pathway, and Msr-related redox status in the kidneys of rats. Therefore, in this experimental study, a total of 32 CD-1 rats were randomized into 4 groups and treated with 30-, 60-, and 120-mg/kg Cu for 24 weeks. Different serum biomarkers suggestive of renal functions, pathological changes, and oxidative stress were analyzed in kidney tissues. Moreover, the levels of the Keap1/Nrf2 signaling pathway and redox status-related gene mRNA and proteins were also detected. The results indicated that Cu exposure dramatically increased the contents of creatinine and carbamide. Furthermore, histopathological alterations and mitochondrial damage in kidneys of rats of different Cu-treated groups were obviously observed. In addition, Cu exposure markedly changed the levels of glutathione, catalase, and total antioxidant capacity, and upregulated the contents of protein carbonyl, nitric oxide, and malondialdehyde. Moreover, higher levels of Cu treatments significantly increased the expression of Keap1/Nrf2 signaling pathway and redox status-related genes (NQO1, SOD-1, TRX, MsrA, MsrB1, MsrB2, MsrB3). Simultaneously, the mRNA expression levels of Nrf2, HO-1, and CAT were upregulated in rats exposed to 30- and 60-mg/kg Cu, but downregulated in the 120-mg/kg Cu group compared with the control group. Moreover, the Keap1/Nrf2 signaling pathway and redox status-related protein expression levels (HO-1, SOD-1, TRX, MsrA, MsrB1, MsrB2) were significantly increased in treated rats. In summary, it is suggested that the Keap1/Nrf2 signaling pathway and activation of Msr prevent Cu-induced nephrotoxicity and attenuate oxidative damage.

Effects of Pasture Type on Metabolism, Liver and Kidney Function, Antioxidant Status, and Plant Secondary Compounds in Plasma of Grazing, Jersey Dairy Cattle During Mid-lactation

Some pasture species are rich in phytochemicals, able to improve milk yield and quality and to reduce the environmental impacts of livestock farming. The phytochemicals interact with the different gene networks within the animal, such as nuclear factor erythroid 2-related factor 2 (NRF2), but their overall impact on animal health remains to be fully understood. The objective of this study was to identify the effects of pasture Legumes and non-leguminous Forbs containing high bioactive compounds on metabolism and activity of the liver, antioxidant response, kidney function, and inflammation of dairy cows using a large array of blood parameters associated with metabolism and the innate immune system. For this purpose, 26 parameters and the concentration of certain bioactive compounds were assessed in blood plasma, collected from the Jersey cows grazing either Grass, Legume, or Forb-based pastures. In addition, serum collected from all the cows was utilized to detect the changes in NRF2 activation in bovine mammary alveolar cells (MACT) and hepatocytes. Compared with Grass, the cows that grazed both Forb and Legume pastures had lower β-hydroxybutyric acid (BHB) and creatinine and larger vitamin E and the ferric reducing ability of the plasma, supporting an improved antioxidative status for these animals. Compared with both Grass and Legume, the cows that graze Forb pasture had lower urea and urea to creatinine ratio, and lower creatinine, indicating a better kidney function. The cows grazing Legume pasture had greater hematocrit, bilirubin, cholesterol, albumin, β-carotene, retinol, and thiol groups but lower ceruloplasmin, paraoxonase, and myeloperoxidase (MPO) than those grazed Grass and Forb pastures, indicating a positive effect of Legume pasture on the liver, oxidative stress, and red blood cells. The plasma of cows in the various pastures was enriched with various isoflavonoids, especially the cows grazed on Forb and Legume pastures, which likely contributed to improving the antioxidative status of those cows. However, this effect was likely not due to the higher activation of NRF2. Overall, these results indicate that Forb and Legume pastures rich in secondary metabolites do not strongly affect the metabolism but can improve the status of the liver and the kidney and improve the efficiency of N utilization and antioxidant response, compared with the Grass pasture.

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

Objectives: Geraniol, a natural monoterpene, is an essential oil component of many plants. Methotrexate is an anti-metabolite drug, used for cancer and autoimmune conditions; however, clinical uses of methotrexate are limited by its concomitant renal injury. This study investigated the efficacy of geraniol to prevent methotrexate-induced acute kidney injury and via scrutinizing the Keap1/Nrf2/HO-1, P38MAPK/NF-κB and Bax/Bcl2/caspase-3 and -9 pathways. Methods: Male Wister rats were allocated into five groups: control, geraniol (orally), methotrexate (IP), methotrexate and geraniol (100 and 200 mg/kg). Results: Geraniol effectively reduced the serum levels of creatinine, urea and Kim-1 with an increase in the serum level of albumin when compared to the methotrexate-treated group. Geraniol reduced Keap1, escalated Nrf2 and HO-1, enhanced the antioxidant parameters GSH, SOD, CAT and GSHPx and reduced MDA and NO. Geraniol decreased renal P38 MAPK and NF-κB and ameliorated the inflammatory mediators TNF-α, IL-1β, IL-6 and IL-10. Geraniol negatively regulated the apoptotic mediators Bax and caspase-3 and -9 and increased Bcl2. All the biochemical findings were supported by the alleviation of histopathological changes in kidney tissues. Conclusion: The current findings support that co-administration of geraniol with methotrexate may attenuate methotrexate-induced acute kidney injury.

Evaluation by different mechanisms of the protective effects of vitamin B12 on methotrexate nephrotoxicity

Methotrexate is used for cure of many cancer types. It has many side effects. For this reason, obtaining a nephroprotective agent is obligatory. In the study, our aim is to determine probable effects of Vitamin B12 on MTX caused kidney damages in rats. Rats were randomly divided into 4 groups, including 8 animals in each group. Control group, VitB12 group (3 μg-kg-ip B12 throughout 15 days), MTX group (at the 8th day of experiment, a single dose of 20 mg-kg-ip MTX), Vit B12 + MTX group (3 μg-kg-ip B12 throughout 15 days and at the 8th day of experiment, a single dose of 20 mg-kg-ip MTX) Animals were anesthetized and kidney tissues were removed to evaluate biochemically, immunohistochemically and histopathologycally. There were histopathological deteriorations, rises of apoptotic cells, expressions of heat shock proteins, endoplasmic reticulum stress and inflammation markers in the MTX group. In the MTX group, Superoxide Dismutase (SOD), Total Antioxidant Status (TAS) and Catalase (CAT) levels decreased, but Total Oxidant Status TOS, Malondialdehyde (MDA) and interleukin-6 (IL6) levels increased. In addition, there was amelioration in kidney tissue in Vit B12 + MTX group compared to the MTX group. We suggest that Vit B12 can be used to reduce the toxic effects of MTX.

Formononetin ameliorates IL‑13‑induced inflammation and mucus formation in human nasal epithelial cells by activating the SIRT1/Nrf2 signaling pathway

Formononetin has proven to be anti‑inflammatory and able to alleviate symptoms of certain allergic diseases. The present study aimed to determine and elucidate the potential effects of formononetin in allergic rhinitis. JME/CF15 cells were pretreated with formononetin at different doses, followed by stimulation with IL‑13. Cell Counting Kit‑8 assay was performed to determine the cytotoxicity of formononetin. The expression levels of inflammation‑related proteins, histamine, IgE, TNF‑α, IL‑1β, IL‑6, granulocyte‑macrophage colony‑stimulating factor and eotaxin in IL‑13‑stimulated JME/CF15 cells were detected using ELISAs. The expression levels of phosphorylated‑NF‑κB p65, NF‑κB p65 and cyclooxygenase‑2 (Cox‑2) were analyzed using western blotting. Reverse transcription‑quantitative PCR, western blotting and immunofluorescence were performed to measure the levels of mucin 5AC oligomeric mucus/gel‑forming. Expression levels of sirtuin 1 (SIRT1) and nuclear erythroid factor 2‑related factor 2 (Nrf2) proteins were also measured using western blotting. The results of the present study revealed that formononetin exerted no cytotoxic effect on the viability of JME/CF15 cells. Following stimulation of JME/CF15 cells with IL‑13, formononetin suppressed the upregulated expression levels of proinflammatory cytokines. IL‑13‑induced formation of mucus was also attenuated by formononetin treatment. Furthermore, it was found that the SIRT1/Nrf2 signaling pathway was activated in formononetin‑treated JME/CF15 cells, whereas treatment with the SIRT1 inhibitor, EX527, reversed the effects of formononetin on IL‑13‑induced inflammation and mucus formation in JME/CF15 cells. In conclusion, the findings of the current study indicated that formononetin may activate the SIRT1/Nrf2 signaling pathway, thereby inhibiting IL‑13‑induced inflammation and mucus formation in JME/CF15 cells. These results suggested that formononetin may represent a promising agent for the treatment of allergic rhinitis.

Assessing the mechanisms of action of natural molecules/extracts for phase-directed wound healing in hydrogel scaffolds

Hydrogels are proving to be very versatile as wound healing devices. In addition to their capabilities of providing a moist cellular environment and adaptive mechanical properties mimicking the extracellular matrix, they allow the incorporation of small molecules, which have potential impacts on cellular behaviour, in their nanostructures. This strategy can allow for specific targeting of the different stages of wound healing namely hemostasis, inflammation, and proliferative and remodelling phases. The latter include interlinked processes such as angiogenesis, collagen synthesis, growth factor release, collagen maturation and re-epithelialization. In this review, we attempt to match the mechanisms of action of natural molecules/extracts to the different stages of wound healing so that they can be used in a novel approach of multiphase-directed tissue regeneration using loaded hydrogel scaffolds.

Nephroprotective effect of naringin in methotrexate induced renal toxicity in male rats

The current work aims to study the nephroprotective potential of naringin (NG), a flavanone derived from citrus fruits, in methotrexate (MTX)-induced renal toxicity. Thirty male rats were divided into five groups; control group (IP saline), MTX group (IP single dose, 20 mg/kg), and three groups co-treated with MTX and naringin (IP daily dose; 20, 40, and 80 mg/kg, respectively). Kidney tissues were used to investigate renal function, oxidative stress, lipid peroxidation, and caspase-3 activity. Biochemical cytokine analysis was performed in addition to ultrastructural examinations of kidney tissue. When compared to the MTX-treated rats, MTX+NG significantly reduced the levels of urea, creatinine, MDA, NO, TNFα, IL-6, and caspase-3 activity. A significant increase in the levels of the antioxidant enzymes and GSH were also noted. Additionally, naringin ameliorated the apparent ultrastructural changes observed in the glomeruli and renal tubules of MTX-intoxicated rats. Noticeable structural improvements of glomerular lesions, proximal, and distal convoluted tubular epithelium were observed in MTX+NG treated animals, including podocytes with regular foot processes, perfectly organized filtration barrier, no signs of GBM thickening, organized brush border, and normal architecture of microvilli. Naringin (80 mg/kg) had the maximum amelioration effect. To the best of our knowledge, this is the first study to investigate the ultrastructural manifestations of naringin and/or MTX on the kidney of rats. Taken all, naringin has a potent therapeutic effect and can be used in adjuvant therapy to prevent MTX-induced nephrotoxicity. Nevertheless, the molecular mechanism underlying the nephroprotective capacity of naringin needs further investigation.

Diosmetin Ameliorates Vascular Dysfunction and Remodeling by Modulation of Nrf2/HO-1 and p-JNK/p-NF-κB Expression in Hypertensive Rats

Diosmetin is a citrus flavonoid that has antioxidant and anti-inflammatory effects. This study examined the effect of diosmetin on blood pressure and vascular alterations and its underlying mechanisms in experimentally hypertensive rats. Male Sprague rats were administered Nω-nitro-l-arginine methyl ester L-NAME for five weeks and were given diosmetin at doses of 20 or 40 mg/kg or captopril (5 mg/kg) for two weeks. Diosmetin alleviated hypertension, improved endothelial dysfunction, and suppressed the overactivity of sympathetic nerve-mediated vasoconstriction in aorta and mesentery hypertensive rats (p < 0.05). Increases in plasma and aortic tissue malondialdehyde (MDA) and carotid superoxide generations and reductions of plasma superoxide dismutase, catalase, and nitric oxide in hypertensive rats were ameliorated by diosmetin (p < 0.05). Diosmetin increased the protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in hypertensive rats. Furthermore, diosmetin mitigated hypertrophy and collagen accumulation of the aortic wall in L-NAME rats. It exhibited an anti-inflammatory effect by reducing interleukin-6 (IL-6) accumulation and by overexpressing the phospho-c-Jun N-terminal kinases (p-JNK) and the phospho-nuclear factor-kappaB (p-NF-κB) proteins in the aorta (p < 0.05). Captopril was a positive control substance and had similar effects to diosmetin. In summary, diosmetin reduced blood pressure and alleviated vascular abnormalities in L-NAME-treated rats. These effects might be related to antioxidant and anti-inflammatory effects as well as to the modulation of the expression of the Nrf2/HO1 and p-JNK/NF-κB proteins.

Visnagin prevents isoproterenol-induced myocardial injury by attenuating oxidative stress and inflammation and upregulating Nrf2 signaling in rats

Oxidative tissue injury and inflammatory responses play major roles in cardiovascular diseases and heart failure. Visnagin (VIS) is a natural bioactive component of Ammi visnaga, with promising radical scavenging and anti-inflammatory activities. This study explored the protective effect of VIS against isoproterenol (ISO)-induced acute myocardial injury and oxidative stress in rats. VIS was supplemented for 14 days, and the rats received ISO (100 mg/kg) twice at an interval of 24 h. ISO-induced myocardial injury was characterized by elevated serum CK-MB, LDH, and troponin-I associated with increased heart weight and several histopathological changes. ISO increased reactive oxygen species (ROS), malondialdehyde (MDA), NF-κB p65, TNF-α, IL-6, and decreased glutathione and antioxidant enzymes in rats' hearts. VIS prevented myocardial injury and ameliorated the cardiac function markers, ROS, MDA, NF-κB p65, and pro-inflammatory cytokines in ISO-intoxicated rats. In addition, VIS decreased Bax mRNA and caspases, and upregulated Nrf2, HO-1, Bcl-2, and PPARγ. Molecular docking simulations revealed the binding method of VIS to NF-κB, Keap1, and PPARγ. In conclusion, VIS protects against ISO-induced acute myocardial injury by attenuating oxidative tissue injury and reducing key inflammatory and apoptosis markers. In vivo and in silico results showed that activation of Nrf2/HO-1 signaling and PPARγ mediates the cardioprotective effect of VIS.

Formononetin protects against ox-LDL-induced endothelial dysfunction by activating PPAR-γ signaling based on network pharmacology and experimental validation

Formononetin (FMNT), a flavonoid identified from the Chinese herb Astragalus membranaceus, possesses anti-inflammatory or anti-oxidative properties in different human diseases. This study aims to comprehensively elucidate the function of FMNT in atherosclerosis and its underlying mechanisms. Online public databases were used to identify the drug-disease targets. Protein–protein interaction (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were applied to explore the potential targets and signaling pathways involved in FMNT against atherosclerosis. Human umbilical vein endothelial cells (HUVECs) were exposed to oxidized low-density lipoprotein (ox-LDL) to construct an atherosclerosis cell model in vitro. Endothelial cell function was assessed via examining cell proliferation, inflammatory factors, oxidative markers, reactive oxygen species (ROS), and apoptosis. Western blot was performed to detect the expression of cyclooxygenase-2 (COX-2), endothelial nitric oxide synthase (eNOS), cleaved caspase-3, and peroxisome proliferator-activated receptor-γ (PPAR-γ). A total of 39 overlapping target genes of FMNT and atherosclerosis were identified. Through the PPI network analysis, 14 hub genes were screened and found to be closely relevant to inflammation, oxidative stress, and apoptosis. Results of KEGG pathway assays indicated that lots of targets were enriched in PPAR signaling. Functionally, FMNT could protect against ox-LDL-induced inflammatory reaction, oxidative stress, and apoptosis in HUVECs. Moreover, FMNT attenuated ox-LDL-mediated inactivation of PPAR-γ signaling. GW9662, a PPAR-γ antagonist, reversed the inhibitory effect of FMNT on ox-LDL-induced endothelial injury. In conclusion, FMNT alleviates ox-LDL-induced endothelial injury in HUVECs by stimulating PPAR-γ signaling, providing a theoretical basis for employing FMNT as a potential drug to combat atherosclerosis.

Abbreviations: FMNT: formononetin; PPI: protein–protein interaction; GO: Gene Ontology; KEGG: Kyoto Encyclopedia of Genes and Genomes; HUVECs: human umbilical vein endothelial cells; ox-LDL: oxidized low-density lipoprotein; COX-2: cyclooxygenase-2; eNOS: endothelial nitric oxide synthase; PPAR-γ: peroxisome proliferator-activated receptor-γ; CVD: cardiovascular disease; TCM: traditional Chinese medicines; OGDR: oxygen-glucose deprivation/reoxygenation; ROS: reactive oxygen species; FBS: fetal bovine serum; CCK-8: cell counting kit-8; EdU: 5-Ethynyl-2ʹ-deoxyuridine; SOD: antioxidant enzymes superoxide dismutase; MDA: malondialdehyde; DCFH-DA: 2ʹ,7ʹ-dichlorofluorescein-diacetate; PVDF: polyvinylidene fluoride; ANOVA: one-way analysis of variance; PPARs: peroxisome proliferation-activated receptors

Network Pharmacology Combined with Bioinformatics to Investigate the Mechanisms and Molecular Targets of Astragalus Radix-Panax notoginseng Herb Pair on Treating Diabetic Nephropathy

Background

Astragalus Radix (AR)-Panax notoginseng (PN), a classical herb pair, has shown significant effects in treating diabetic nephropathy (DN). However, the intrinsic mechanism of AR-PN treating DN is still unclear. This study aims to illustrate the mechanism and molecular targets of AR-PN treating DN based on network pharmacology combined with bioinformatics.

Materials and Methods

The Traditional Chinese Medicine Systems Pharmacology database was used to screen bioactive ingredients of AR-PN. Subsequently, putative targets of bioactive ingredients were predicted utilizing the DrugBank database and converted into genes on UniProtKB database. DN-related targets were retrieved via analyzing published microarray data (GSE30528) from the Gene Expression Omnibus database. Protein-protein interaction networks of AR-PN putative targets and DN-related targets were established to identify candidate targets using Cytoscape 3.8.0. GO and KEGG enrichment analyses of candidate targets were reflected using a plugin ClueGO of Cytoscape. Molecular docking was performed using AutoDock Vina software, and the results were visualized by Pymol software. The diagnostic capacity of hub genes was verified by receiver operating characteristic (ROC) curves.

Results

Twenty-two bioactive ingredients and 189 putative targets of AR-PN were obtained. Eight hundred and fifty differently expressed genes related to DN were screened. The PPI network showed that 115 candidate targets of AR-PN against DN were identified. GO and KEGG analyses revealed that candidate targets of AR-PN against DN were mainly involved in the apoptosis, oxidative stress, cell cycle, and inflammation response, regulating the PI3K-Akt signaling pathway, cell cycle, and MAPK signaling pathway. Moreover, MAPK1, AKT1, GSK3B, CDKN1A, TP53, RELA, MYC, GRB2, JUN, and EGFR were considered as the core potential therapeutic targets. Molecular docking demonstrated that these core targets had a great binding affinity with quercetin, kaempferol, isorhamnetin, and formononetin components. ROC curve analysis showed that AKT1, TP53, RELA, JUN, CDKN1A, and EGFR are effective in discriminating DN from controls.

Conclusions

AR-PN against DN may exert its renoprotective effects via various bioactive chemicals and the related pharmacological pathways, involving multiple molecular targets, which may be a promising herb pair treating DN. Nevertheless, these results should be further validated by experimental evidence.

Changes of renal histopathology and the role of Nrf2/HO-1 in asphyxial cardiac arrest model in rats

PURPOSE

To investigate the role of Nrf2/HO-1 in renal histopathological ailments time-dependently in asphyxial cardiac arrest (CA) rat model.

METHODS

Eighty-eight Sprague Dawley male rats were divided into five groups of eight rats each. Asphyxial CA was induced in all the experimental rats except for the sham group. The rats were sacrificed at 6 hours, 12 hours, one day and two days post-CA. Serum blood urea nitrogen (BUN), creatinine (Crtn) and malondialdehyde from the renal tissues were evaluated. Hematoxylin and eosin and periodic acid-Schiff staining were done to evaluate the renal histopathological changes in the renal cortex. Furthermore, Nrf2/HO-1 immunohistochemistry (ihc) and western blot analysis were performed after CA.

RESULTS

The survival rate of rats decreased in a time-dependent manner: 66.6% at 6 hours, 50% at 12 hours, 38.1% in one day, and 25.8% in two days. BUN and serum Crtn markedly increased in CA-operated groups. Histopathological ailments of the renal cortical tissues increased significantly from 6 hours until two days post-CA. Furthermore, Nrf2/HO-1 expression level significantly increased at 6 hours, 12 hours, and one day.

CONCLUSIONS

The survival rate decreased time-dependently, and Nrf/HO-1 expression increased from 6 hours with the peak times at 12 hours, and one day post-CA.

Nephroprotective activity of natural products against chemical toxicants: The role of Nrf2/ARE signaling pathway

Nephropathy can occur following exposure of the kidneys to oxidative stress. Oxidative stress is the result of reactive oxygen species (ROS) formation due to intracellular catabolism or exogenous toxicant exposure. Many natural products (NPs) with antioxidant properties have been used to demonstrate that oxidative damage-induced nephrotoxicity can be ameliorated or at least reduced through stimulation of the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. Nrf2 is a basic leucine zipper (bZip) transcription factor that regulates gene expression of the antioxidant response elements (ARE). Nrf2 is involved in the cellular antioxidant-detoxification machinery. Nrf2 activation is a major mechanism of nephroprotective activity for these NPs, which facilitates its entry into the nucleus, primarily by inhibiting Kelch like-ECH-associated protein 1 (Keap1). The purpose of this article was to review the peer-reviewed literature of NPs that have shown mitigating effects on renal disorder by stimulating Nrf2 and thereby suggesting potential new therapeutic or prophylactic strategies against kidney-damaging xenobiotics.

Formononetin attenuates H2O2-induced cell death through decreasing ROS level by PI3K/Akt-Nrf2-activated antioxidant gene expression and suppressing MAPK-regulated apoptosis in neuronal SH-SY5Y cells

Formononetin is an isoflavone, found in herbs like Trifolium pratense, which executes a variety of physiological activities including anti-neurodegenerative effect. However, the molecular mechanism of formononetin-mediated neuroprotection remains unclear. In this study, we investigated the protective effect of formononetin on hydrogen peroxide (H₂O₂)-induced death of human neuroblastoma SH-SY5Y cells and its underlying molecular mechanism. Formononetin suppressed H₂O₂-induced cytotoxicity. H₂O₂-induced increase in the intracellular reactive oxygen species (ROS) levels was decreased by formononetin, together with the enhanced expression of the antioxidant genes. H₂O₂-induced elevation of the Bax/Bcl-2 ratio and cleaved caspase-3 and caspase-7 levels were lowered by formononetin treatment. Moreover, formononetin repressed H₂O₂-induced phosphorylation of mitogen-activated protein kinases (MAPKs). Nuclear factor erythroid 2-related factor 2 (Nrf2) siRNA decreased antioxidant gene expression and elevated the H₂O₂-induced ROS level in the formononetin-treated cells. Furthermore, the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling is involved in the activation of the nuclear translocation of Nrf2. These results indicate that the neuroprotective effect of formononetin against H₂O₂-induced cell death is due to a decrease in the ROS level with the enhanced expression of the antioxidant genes through activation of the PI3K/Akt-Nrf2 signaling. In addition, formononetin suppressed apoptosis through inhibition of phosphorylation of MAPKs in SH-SY5Y cells. Thus, formononetin is a potential therapeutic agent for the treatment of neurodegenerative diseases.

Diallyl disulfide ameliorates methotrexate-induced nephropathy in rats: Molecular studies and network pharmacology analysis

Methotrexate (MTX) is a promising chemotherapeutic agent. Its medical use is limited by induced nephropathy. Our study was designed to explore the reno-protective effect of diallyl disulfide (DADS), an organosulfur compound of garlic oil, on MTX-induced nephropathy. Adult rats were randomly divided into 4 groups; normal control, DADS (50 mg kg^-1  day^-1 , p.o.), MTX (20 mg/kg, i.p.) and DADS+MTX. DADS significantly decreased serum creatinine, urea, uric acid, and albumin levels with an improvement of final body weight. Additionally, DADS markedly attenuated MTX-induced elevations in renal MDA and NO 2 - contents with an increase in GSH content and SOD activity. Mechanistically, DADS effectively down-regulated mRNA expression level of renal p38 and NF-κB. Additionally, DADS positively regulated the NRF2 gene with a remarkable inhibition of Keap-1 gene. Furthermore, DADS up-regulated BCL2 protein and remarkably suppressed the expression of both BAX and caspase-3 proteins. Overall, DADS has favorable renal protection against MTX-induced nephropathy via modulation of Keap-1/NRF2, p38/NF-κB, and BCL2/BAX/caspase-3 signaling. PRACTICAL APPLICATIONS: Diallyl disulfide is one of the organosulfur compounds of garlic oil. Our study demonstrated that DADS substantially alleviated the decline of kidney function and renal injury induced by MTX. The antioxidative, anti-inflammatory, and anti-apoptotic properties may constitute an important part of its therapeutic applications via regulation of p38/NF-κB, Keap-1/NRF2, and BCL2/BAX/caspase-3 signaling pathways. Therefore, DADS could be a potential therapeutic adjunct in cancer chemotherapy to decrease the associated side effects of MTX. It should be further explored clinically as a protective agent for MTX-treated cancer patients.