Epigallocatechin-3-gallate activates Nrf2/HO-1 signaling pathway in cisplatin-induced nephrotoxicity in rats

Natural products modulate phthalate-associated miRNAs and targets

Phthalates are widespread and commonly used plasticizers that lead to adverse health effects. Several natural products provide a protective effect against phthalates. Moreover, microRNAs (miRNAs) are regulated by natural products and phthalates. Therefore, miRNAs' impacts and potential targets may underlie the mechanism of phthalates. However, the relationship between phthalate-modulated miRNAs and phthalate protectors derived from natural products is poorly understood and requires further supporting information. In this paper, we review the adverse effects and potential targets of phthalates on reproductive systems as well as cancer and non-cancer responses. Information on natural products that attenuate the adverse effects of phthalates is retrieved through a search of Google Scholar and the miRDB database. Moreover, information on miRNAs that are upregulated or downregulated in response to phthalates is collected, along with their potential targets. The interplay between phthalate-modulated miRNAs and natural products is established. Overall, this review proposes a straightforward pathway showing how phthalates modulate different miRNAs and targets and cause adverse effects, which are partly attenuated by several natural products, thereby providing a direction for investigating the natural product-miRNA-target axis against phthalate-induced effects.

The anti-inflammatory properties of green tea extract protect against gentamicin-induced kidney injury

We assessed in vivo the protective effects and underlying antioxidant and anti-inflammatory properties of dry green tee extract (GTE) on glomerular and tubular kidney function and structure in an experimental model of gentamicin (GEN)-induced nephrotoxicity. Wistar rats were divided into four groups and treated daily for 10 days. The control group received distilled water; the GTE group received 20 μg/g body weight (BW) GTE by gavage; the GEN group received 100 mg/g BW GEN intraperitoneally; and the GEN+GTE group received GTE and GEN simultaneously, as described above. At the beginning and end of treatment, the serum creatinine, fractional excretion of sodium and potassium, and plasma heme oxygenase (HO)-1 levels and oxidative stress (OS) were assessed. At the end of the experiment, kidney fragments were collected for histological evaluation and immunohistochemical studies of cyclooxygenase (COX)-2 and nuclear factor (NF)kB. The levels of interleukin (IL)-1b, IL-4, IL-6, IL-10 and monocyte chemotactic protein (MCP)-1 were measured in kidney tissue. The results showed that GTE attenuated significantly kidney structural injury and prevented GEN-induced kidney functional injury (glomerular and tubular function). GTE significantly attenuated the kidney tissue increase of the proinflammatory mediators NF-kB, COX2, IL-1b and MCP-1 and significantly increased the kidney expression of the anti-inflammatory cytokines IL-6 and IL-10. However, GTE did not prevent OS increase in GEN-treated animals. In conclusion, GTE protected against GEN nephrotoxicity, likely due to direct blockade of the inflammatory cascade, which might had occurred independently of its antioxidant effect.

Piracetam mitigates nephrotoxicity induced by cisplatin via the AMPK-mediated PI3K/Akt and MAPK/JNK/ERK signaling pathways

AIMS

Cisplatin (CDDP) is commonly employed as an antineoplastic agent, but its use is significantly limited by the occurrence of dose-dependent nephrotoxicity, the detailed mechanisms of which remain unclear. This research is aimed to explore the molecular mechanisms of Piracetam (PIR)'s protective effects on nephrotoxicity resulting from CDDP exposure and to elucidate the mechanisms responsible for these effects.

MAIN METHODS

PIR was given in dosages of 100 and 300 mg/kg body weight for a duration of 15 days; concurrently, on the last day, a single 10 mg/kg dose of CDDP was delivered via intraperitoneal injection. Forty-eight hours post-CDDP injection, the animals were sacrificed to assess nephrotoxicity. Blood samples and renal tissues were taken for biochemical and histopathological investigations. Serum creatinine and blood urea nitrogen (BUN) were measured. AMP-activated protein kinase (AMPK), caspase-9 and nuclear factor kappa b p65 (NF-κB p65) were assessed by immunohistochemistry method. Enzyme-linked immunosorbent assay (ELISA) analysis was employed to determine cytochrome c (Cyt. c), Bcl-2-associated X-protein (BAX), caspase-3, nuclear factor erythroid 2-related factor 2 (Nrf2), Heme oxygenase-1 (HO-1), superoxide dismutase (SOD), tumor necrosis factor alpha (TNF-α), myeloperoxidase (MPO), and interleukin-1β (IL-1β) levels in renal tissue homogenates. The mRNA levels of tumor protein P53 (TP53), phosphatidylinositol-3 kinase (PI3K), protein kinase B (Akt), p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinases (ERK), and c-Jun N-terminal kinases (JNK) were tested by quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, histopathological evaluations of the renal tissues and the binding affinity of PIR to AMPK by molecular docking were also performed.

KEY FINDINGS

Pre-treatment with PIR enhanced renal function markers such as urea and creatinine, mitigated histological damage, and diminished inflammatory cell presence in renal tubules. PIR demonstrated antioxidant effects by reestablishing the equilibrium between pro-oxidants and antioxidants such as MPO, HO-1, Nrf2, as well as SOD. Furthermore, PIR inhibited the inflammatory pathways through the MAPK/NF-κB pathway. Additionally, PIR counteracted the CDDP-induced decline in PI3K/Akt activity and hindered caspase-dependent apoptotic processes.

SIGNIFICANCE

In summary, PIR appears to be an effective therapeutic strategy for reducing CDDP-induced nephrotoxicity, attributed to its antioxidant, anti-inflammatory, and antiapoptotic mechanisms. Consequently, PIR may serve as a complementary treatment alongside CDDP to alleviate nephrotoxicity associated with CDDP.

Nicorandil attenuates cisplatin-induced acute kidney injury in rats via activation of PI3K/AKT/mTOR signaling cascade and inhibition of autophagy

Cisplatin is a highly effective antitumor agent, but its clinical use is limited due to critical adverse reactions including acute kidney injury (AKI). Nicorandil is an approved antianginal agent decreasing ischemia by potassium channel opening. The aim of this study was to investigate the nephroprotective effects of nicorandil and the possible role of activating PI3K/AKT/mTOR pathway in ameliorating cisplatin-induced AKI. Forty male Wistar rats were randomly allocated in 4 groups (n = 10). Group I: rats received the vehicle and served as control. Group II: rats received a single dose of cisplatin (7 mg/kg, i.p) on the 10th day of the experiment and served as AKI group. Group III: rats received cisplatin as in group II and nicorandil (3 mg/kg/day, p.o) for 14 days. Group IV: rats received cisplatin and nicorandil as in group III as well as wortmannin (15 μg/kg, i.v) for 14 days. Nicorandil exhibited obvious nephroprotective effects via the activation of PI3K/AKT/mTOR pathway. Moreover, nicorandil succeed to reduce the expression of the autophagy markers beclin-1 and LC-3II/I. In parallel, nicorandil showed anti-inflammatory and antiapoptotic effects via inhibition of NF-κB inflammatory pathway and depression of Bax/Bcl-2 ratio. Wortmannin, the PI3K inhibitor, was used to demonstrate the proposed pathway. Our study showed the nephroprotective effects of nicorandil in cisplatin-induced AKI in rats via activation of PI3K/AKT/mTOR signaling cascade, inhibition of autophagy, anti-inflammatory, anti-apoptotic, anti-oxidant activities. Thus, nicorandil could represent a promising renoprotective agent in cancer patients treated with cisplatin.

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.

Illumination of Hydroxyl Radical in Kidney Injury and High-Throughput Screening of Natural Protectants Using a Fluorescent/Photoacoustic Probe

The hydroxyl radical (•OH) is shown to play a crucial role in the occurrence and progression of acute kidney injury (AKI). Therefore, the development of a robust •OH probe holds great promise for the early diagnosis of AKI, high-throughput screening (HTS) of natural protectants, and elucidating the molecular mechanism of intervention in AKI. Herein, the design and synthesis of an activatable fluorescent/photoacoustic (PA) probe (CDIA) for sensitive and selective imaging of •OH in AKI is reported. CDIA has near-infrared fluorescence/PA channels and fast activation kinetics, enabling the detection of the onset of •OH in an AKI model. The positive detection time of 12 h using this probe is superior to the 48-hour detection time for typical clinical assays, such as blood urea nitrogen and serum creatinine detection. Furthermore, a method is established using CDIA for HTS of natural •OH inhibitors from herbal medicines. Puerarin is screened out by activating the Sirt1/Nrf2/Keap1 signaling pathway to protect renal cells in AKI. Overall, this work provides a versatile and dual-mode tool for illuminating the •OH-related pathological process in AKI and screening additional compounds to prevent and treat AKI.

CTRP3 attenuates inflammation, oxidative and cell death in cisplatin induced HK-2 cells

Cisplatin has been widely studied and found to be a highly effective anti-tumor drug. It has several side effects, including acute kidney injury (AKI). Cisplatin-induced AKI can be primarily attributed to oxidative stress, inflammation, and apoptosis. The CTRP3 adipokine is a new adipokine that exhibits antioxidant, anti-inflammatory, and antiapoptotic properties. Despite this, the role of CTRP3 in AKI remain unclear. In cisplatin-induced AKI models, our findings demonstrated that CTRP3 expression was decreased in human proximal tubule epithelial cells (HK-2). In the in vitro experiments, HK-2 cells were first transfected with an overexpression plasmid of CTRP3 (pcDNA-CTRP3) or a small interfering RNA for CTRP3 (si-CTRP3) and induced by cisplatin; and cell oxidative stress, inflammation, proliferation, and apoptosis were found to be present. Overexpressing CTRP3 inhibited oxidative stress through decreasing malondialdehyde (MDA) levels and increasing the activity of SOD and CAT. The mRNA levels of SOD1 and SOD2 were increased in response to CTRP3 overexpression. Additionally, CTRP3 decreased TNF-α and MCP-1 levels. Moreover, CTRP3 overexpression increased cisplatin-induced cell activity and decreased cell apoptosis, as indicated by the elevated numbers of EdU positive cells and decreased numbers of apoptotic cells. Consistent with these results, the overexpression of CTRP3 effectively elevated the mRNA levels of Bcl-2 and reduced the mRNA levels of Bax. In contrast, inhibition of CTRP3 expression by si-CTRP3 reversed the cisplatin-induced indices. Mechanistically, we found that the overexpression of CTRP3 can increase expression of Nrf2 and inhibit the activation of MAPK phosphorylation (ERK, JNK, and p38). Furthermore, inhibition of ERK, JNK and p38 activity eliminated aggravation of cisplatin-induced inflammation and apoptosis caused by CTRP3 knockdown. Additionally, the cisplatin-induced oxidative stress and activation of MAPK phosphorylation (ERK, JNK, and p38) in HK-2 cells were reversed by Nrf2 suppression by siRNA. Collectively, these results indicated that CTRP3 may identify as a novel target for AKI treatment and protect against cisplatin-induced AKI through the Nrf2/MAPK pathway.

(-)-Epigallocatechin-3-Gallate Attenuates the Adverse Reactions Triggered by Selenium Nanoparticles without Compromising Their Suppressing Effect on Peritoneal Carcinomatosis in Mice Bearing Hepatocarcinoma 22 Cells

Increasing evidence shows that selenium and polyphenols are two types of the most reported compounds in tumor chemoprevention due to their remarkable antitumor activity and high safety profile. The cross-talk between polyphenols and selenium is a hot research topic, and the combination of polyphenols and selenium is a valuable strategy for fighting cancer. The current work investigated the combination anti-peritoneal carcinomatosis (PC) effect of selenium nanoparticles (SeNPs) and green tea (Camellia sinensis) polyphenol (-)-epigallocatechin-3-gallate (EGCG) in mice bearing murine hepatocarcinoma 22 (H22) cells. Results showed that SeNPs alone significantly inhibited cancer cell proliferation and extended the survival time of mice bearing H22 cells. Still, the potential therapeutic efficacy is accompanied by an approximately eighty percent diarrhea rate. When EGCG was combined with SeNPs, EGCG did not affect the tumor proliferation inhibition effect but eliminated diarrhea triggered by SeNPs. In addition, both the intracellular selectively accumulated EGCG without killing effect on cancer cells and the enhanced antioxidant enzyme levels in ascites after EGCG was delivered alone by intraperitoneal injection indicated that H22 cells were insensitive to EGCG. Moreover, EGCG could prevent SeNP-caused systemic oxidative damage by enhancing serum superoxide dismutase, glutathione, and glutathione peroxidase levels in healthy mice. Overall, we found that H22 cells are insensitive to EGCG, but combining EGCG with SeNPs could protect against SeNP-triggered diarrhea without compromising the suppressing efficacy of SeNPs on PC in mice bearing H22 cells and attenuate SeNP-caused systemic toxicity in healthy mice. These results suggest that EGCG could be employed as a promising candidate for preventing the adverse reactions of chemotherapy including chemotherapy-induced diarrhea and systemic toxicity in cancer individuals.

EGCG adjuvant chemotherapy: Current status and future perspectives

The resistance of cancer cells to chemotherapeutic drugs greatly reduces the therapeutic effect in cancer patients, and the toxic side effects caused by chemotherapy also seriously affect the quality of life of patients. The combination of epigallocatechin-3-gallate (EGCG), the main active ingredient in tea, with cisplatin, 5-FU, doxorubicin and paclitaxel enhances their sensitizing effect on tumors and combats the drug resistance of cancer cells. These effects seem to be mediated by a variety of mechanisms, including combating drug resistance mediated by cancer stem cells, enhancing drug sensitivity, inducing cell cycle arrest and apoptosis, and blocking angiogenesis. In addition, EGCG can suppress a series of adverse effects caused by chemotherapy, such as gastrointestinal disorders, nephrotoxicity and cardiotoxicity, through its anti-inflammatory and antioxidant effects and improve the quality of life of patients. However, the low bioavailability and off-target effects of EGCG and its reactivity with some chemotherapeutic agents limit its clinical application. The nanomodification of EGCG and chemotherapeutic drugs not only enhances the antitumor activity but also prolongs the survival time of tumor-bearing mice, and has the advantage of low toxicity. Therefore, this review aims to discuss the current status and challenges regarding the use of EGCG in combination with chemotherapy drugs in the treatment of cancer. In general, EGCG is a promising adjuvant for chemotherapy.

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.

Rosmarinic acid mitigates chlorpyrifos-induced oxidative stress, inflammation, and kidney injury in rats by modulating SIRT1 and Nrf2/HO-1 signaling

Chlorpyrifos (CPF) is a widely used broad-spectrum pesticide with multi-organ toxic effects. Oxidative stress was found to play a role in the deleterious effects of CPF, including nephrotoxicity. This study investigated the protective effect of the antioxidant polyphenol rosmarinic acid (RA) against CPF-induced kidney injury, with an emphasis on oxidative injury, inflammation, SIRT1, and Nrf2/HO-1 signaling. Rats received 10 mg/kg CPF and 25, 50, and 100 mg/kg RA orally for 28 days, and the samples were collected for analysis. CPF increased serum urea and creatinine and kidney Kim-1 and caused several histopathological alterations. ROS, MDA, NO, NF-κB p65, TNF-α, and IL-1β were elevated in the kidney of CPF-intoxicated rats. RA ameliorated kidney function markers, prevented tissue injury, suppressed ROS, MDA, and NO, and downregulated NF-κB p65, TNF-α, and IL-1β in CPF-intoxicated rats in a dose-dependent manner. RA decreased Bax, caspase-3, oxidative DNA damage, and Keap1, boosted antioxidant enzymes and Bcl-2, and upregulated Nrf2, HO-1, and SIRT1 in CPF-administered rats. Molecular docking simulation revealed the binding affinity of RA toward NF-κB, Keap1, HO-1, and SIRT1. In conclusion, RA prevented CPF nephrotoxicity by attenuating oxidative stress, inflammation, and apoptosis and upregulating SIRT1 and Nrf2/HO-1 signaling.

Aqueous core epigallocatechin gallate PLGA nanocapsules: characterization, antibacterial activity against uropathogens, and in vivo reno-protective effect in cisplatin induced nephrotoxicity

Epigallocatechin-3-gallate (EGCG) was isolated from Cycas thouarsii leaves for the first time and encapsulated in aqueous core poly(lactide-co-glycolide) (PLGA) nanocapsules (NCs). This work investigates antimicrobial activity and in vivo reno-protective effects of EGCG-PLGA NCs in cisplatin-induced nephrotoxicity. A double emulsion solvent evaporation process was adopted to prepare PLGA NCs loaded with EGCG. Particle size, polydispersity index (PDI), zeta potential, percent entrapment efficiency (%EE), structural morphology, and in vitro release platform were all studied in vitro. The optimum formula (F2) with particle size (61.37 ± 5.90 nm), PDI (0.125 ± 0.027), zeta potential (-11.83 ± 3.22 mV), %EE (85.79 ± 5.89%w/w), initial burst (36.85 ± 4.79), and percent cumulative release (87.79 ± 9.84) was selected for further in vitro/in vivo studies. F2 exhibited an enhanced antimicrobial activity against uropathogens as it had lower minimum inhibitory concentration (MIC) values and a more significant impact on bacterial growth than free EGCG. Forty male adult mice were randomly allocated into five groups: control vehicle, untreated methotrexate, MTX groups treated with a daily oral dose of free EGCG, placebo PLGA NCs, and EGCG PLGA NCs (F2) for 10 days. Results showed that EGCG PLGA NCs (F2) exerted promising renoprotective effects compared to free EGCG. EGCG PLGA NCs group induced a significant decrease in kidney index, serum creatinine, kidney injury molecule-1 (KIM-1), NGAL serum levels, and pronounced inhibition of NLPR-3/caspase-1/IL/1β inflammasome pathway. It also significantly ameliorated oxidative stress and decreased NFκB, Bax expression levels. Aqueous core PLGA NCs are a promising formulation strategy that provides high polymeric protection and sustained release pattern for hydrophilic therapeutic agents.

Rhabdomyolysis-induced acute kidney injury and concomitant apoptosis induction via ROS-mediated ER stress is efficaciously counteracted by epigallocatechin gallate

Rhabdomyolysis induced acute kidney injury (RIAKI) is a life-threatening condition responsible for approximately 19-58% of AKI cases worldwide. We performed an intramuscular injection of glycerol (10 mL/kg) in male wistar rats to induce AKI. Epigallocatechin gallate (EGCG) was administered for 3 consecutive days to evaluate its protective effects. We observed significant downregulation in serum creatinine, blood urea nitrogen (BUN) and LDH at different time points on EGCG treatment groups in a dose-dependent manner. Similarly, H&E staining also revealed that EGCG was able to reduce the formation of damaged tubules and tubular necrosis which was prominently spread throughout the kidney tissue of glycerol treatment group. Concomitantly, we observed upregulated inflammation, ER stress and elevated oxidative stress in the glycerol treated group only, which was significantly normalized upon EGCG treatment in both in vitro and in vivo studies. The occurrence of apoptosis in kidney tubules was found to be relatively higher in glycerol treated group and H₂O₂ treated HEK-293 cells. The results obtained after EGCG treatment revealed a significant decrease in apoptotic cell population, which was further validated by immunofluorescence staining against p53 and comet assay in HEK-293 cells and p53 IHC in kidney tissues. Western blotting also revealed a systemic downregulation of intrinsic mitochondrial apoptotic pathway markers such as bax, bcl-2, pro and cleaved caspase 3, caspase 9 and PARP1. Additionally, the results for flow cytometry analysis and TUNEL assay corroborated apoptotic equilibrium. Conclusively, we reckon EGCG as a multi-therapeutic natural product that can be used the for treatment of AKI.

The Self-Administered Use of Complementary and Alternative Medicine (CAM) Supplements and Antioxidants in Cancer Therapy and the Critical Role of Nrf-2-A Systematic Review

Complementary and alternative medicine (CAM) supplements are widely used by cancer patients. Dietary supplements, vitamins and minerals, herbal remedies, and antioxidants are especially popular. In a systematic literature review, 37 studies, each including more than 1000 participants, on CAM, dietary supplement, and vitamin use among cancer patients were identified. Accordingly, cancer patients use antioxidants such as vitamin C (from 2.6% (United Kingdom) to 41.6% (United States)) and vitamin E (from 2.9% (China) to 48% (United States)). Dietary supplements and vitamins are taken for different reasons, but often during conventional cancer treatment involving chemotherapy or radiotherapy and in a self-decided manner without seeking medical advice from healthcare professionals. Drug-drug interactions with dietary supplements or vitamins involving multiple signaling pathways are well described. Since most of the anticancer drugs generate reactive oxygen species (ROS), an adaptive stress response of healthy and malignant cells, mainly driven by the Nrf-2-Keap I network, can be observed. On the one hand, healthy cells should be protected from ROS-overproducing chemotherapy and radiotherapy; on the other hand, ROS production in cancer cells is a "desirable side effect" during anticancer drug treatment. We here describe the paradoxical use of antioxidants and supplements during cancer therapy, possible interactions with anticancer drugs, and the involvement of the Nrf-2 transcription factor.

Electrophilic Aldehyde 4-Hydroxy-2-Nonenal Mediated Signaling and Mitochondrial Dysfunction

Reactive oxygen species (ROS), a by-product of aerobic life, are highly reactive molecules with unpaired electrons. The excess of ROS leads to oxidative stress, instigating the peroxidation of polyunsaturated fatty acids (PUFA) in the lipid membrane through a free radical chain reaction and the formation of the most bioactive aldehyde, known as 4-hydroxynonenal (4-HNE). 4-HNE functions as a signaling molecule and toxic product and acts mainly by forming covalent adducts with nucleophilic functional groups in proteins, nucleic acids, and lipids. The mitochondria have been implicated as a site for 4-HNE generation and adduction. Several studies clarified how 4-HNE affects the mitochondria's functions, including bioenergetics, calcium homeostasis, and mitochondrial dynamics. Our research group has shown that 4-HNE activates mitochondria apoptosis-inducing factor (AIFM2) translocation and facilitates apoptosis in mice and human heart tissue during anti-cancer treatment. Recently, we demonstrated that a deficiency of SOD2 in the conditional-specific cardiac knockout mouse increases ROS, and subsequent production of 4-HNE inside mitochondria leads to the adduction of several mitochondrial respiratory chain complex proteins. Moreover, we highlighted the physiological functions of HNE and discussed their relevance in human pathophysiology and current discoveries concerning 4-HNE effects on mitochondria.

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.

Phytogenic Antioxidants Prolong n-3 Fatty Acid-Enriched Eggs’ Shelf Life by Activating the Nrf-2 Pathway through Phosphorylation of MAPK

Helpful for human health, omega-3 (n-3)-enriched eggs are preferred by consumers. However, antioxidants should be added to the hen’s diet to prevent n-3 fatty acid oxidation due to their unsaturated bonds. A study was designed to investigate the effects of different antioxidants on performance, egg quality, fatty acid profile, oxidation parameters, gene expression, and magnum morphology. A total of 450 hens were divided into five dietary groups. Wheat–flaxseed was used for the basic diet (control) and supplemented with vitamin E (VE), chlorogenic acid (CA), polyphenol (PF), and lutein (L). The experiment lasted for 10 weeks. The eggs were collected on the 5th week and were analyzed for quality, oxidative stability, and fatty acid (FA) content, being stored for 0 d, 7 d, 14 d, 21 d, 28 d, 35 d, and 42 d. The results showed that supplemental VE, PF, CA, and L improved the egg weight and hen day egg production compared to the control group (p < 0.05). The VE, PF, and L groups significantly (p < 0.05) reduced the malondialdehyde (MDA) and maintained the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in the egg yolk. The albumen height and Haugh unit were maintained in the egg yolk till 35 days of storage by the VE, PF, and L groups, while the CA group reduced the albumen quality after 21 d storage. The VE, PF, CA, and lutein maintained the content of alpha-linolenic acid (ALA), during the whole storage period. The total n-3 FA and docosahexaenoic acid (DHA) were retained in the egg yolk till 35 and 28 days of storage, respectively, and slightly decreased after 35 and 28 days in the L groups. The total n-6 (Tn-6) FA was maintained in the yolk till 28 days of storage in the CA and PF groups, respectively. The VE, PF, and L groups upregulated the expression of Nrf-2, P38MAPK, HO-1, SOD-1, and GSH-Px as compared to the CA and control groups. The VE, PF, and L groups significantly increased the magnum primary folds and epithelium height as compared to CA and the control. Thus, it was concluded that the use of PF and L is better at preventing egg quality deterioration and lipid oxidation, maintaining more than 300 mg/egg n-3 FA during storage, by activating the Nrf-2 pathway through the phosphorylation of P38MAPK, and enhancing the phase-2 antioxidant defense enzymes, namely, SOD, GSH-Px, and HO-1.

Correlation between Ferroptosis-Related Gene Signature and Immune Landscape: Prognosis in Breast Cancer

Breast cancer (BC) is the most commonly diagnosed cancer and second leading cause of cancer-related death in women worldwide. Ferroptosis, an iron-dependent newly discovered mode of cell death, can be induced by lenaltinib and plays an important role in the biological behaviors of BC. Therefore, the prognostic value of ferroptosis-related genes (FRGs) in BC warrants further investigation. FRG expression profiles and clinical data were downloaded from The Cancer Genome Atlas (TCGA) database and Gene Expression Omnibus (GEO). Immune-related pathways were found in the functional analysis. Significant differences in enrichment scores for immune cells were observed. Some patients from TCGA-BRCA were included as the training cohort. A six-gene prediction signature was constructed with the least absolute shrinkage and selection operator Cox regression. This model was validated in the rest of the TCGA-BRCA and GEO cohort. The expressions of the six FRGs were verified with real-time quantitative polymerase chain reaction and immunohistochemistry in the Human Protein Atlas. Relapse or metastasis was more likely in the high-risk group. Risk score was an independent predictor of disease-free survival. Collectively, the ferroptosis-related risk model established in this study may serve as an effective tool to predict the prognosis in BC.

The Effect of Polyphenols on Kidney Disease: Targeting Mitochondria

Mitochondrial function, including oxidative phosphorylation (OXPHOS), mitochondrial biogenesis, and mitochondria dynamics, are essential for the maintenance of renal health. Through modulation of mitochondrial function, the kidneys are able to sustain or recover acute kidney injury (AKI), chronic kidney disease (CKD), nephrotoxicity, nephropathy, and ischemia perfusion. Therapeutic improvement in mitochondrial function in the kidneys is related to the regulation of adenosine triphosphate (ATP) production, free radicals scavenging, decline in apoptosis, and inflammation. Dietary antioxidants, notably polyphenols present in fruits, vegetables, and plants, have attracted attention as effective dietary and pharmacological interventions. Considerable evidence shows that polyphenols protect against mitochondrial damage in different experimental models of kidney disease. Mechanistically, polyphenols regulate the mitochondrial redox status, apoptosis, and multiple intercellular signaling pathways. Therefore, this review attempts to focus on the role of polyphenols in the prevention or treatment of kidney disease and explore the molecular mechanisms associated with their pharmacological activity.

Oxidative stress in the pathophysiology of type 2 diabetes and related complications: Current therapeutics strategies and future perspectives

Type 2 diabetes (T2DM) is a persistent metabolic disorder rising rapidly worldwide. It is characterized by pancreatic insulin resistance and β-cell dysfunction. Hyperglycemia induced reactive oxygen species (ROS) production and oxidative stress are correlated with the pathogenesis and progression of this metabolic disease. To counteract the harmful effects of ROS, endogenous antioxidants of the body or exogenous antioxidants neutralise it and maintain bodily homeostasis. Under hyperglycemic conditions, the imbalance between the cellular antioxidant system and ROS production results in oxidative stress, which subsequently results in the development of diabetes. These ROS are produced in the endoplasmic reticulum, phagocytic cells and peroxisomes, with the mitochondrial electron transport chain (ETC) playing a pivotal role. The exacerbated ROS production can directly cause structural and functional modifications in proteins, lipids and nucleic acids. It also modulates several intracellular signaling pathways that lead to insulin resistance and impairment of β-cell function. In addition, the hyperglycemia-induced ROS production contributes to micro- and macro-vascular diabetic complications. Various in-vivo and in-vitro studies have demonstrated the anti-oxidative effects of natural products and their derived bioactive compounds. However, there is conflicting clinical evidence on the beneficial effects of these antioxidant therapies in diabetes prevention. This review article focused on the multifaceted role of oxidative stress caused by ROS overproduction in diabetes and related complications and possible antioxidative therapeutic strategies targeting ROS in this disease.

Quercetin ameliorates Di (2-ethylhexyl) phthalate-induced nephrotoxicity by inhibiting NF-κB signaling pathway

This study aimed to evaluate the possible protective effects of quercetin, a natural flavonoid, against nephrotoxicity induced by Di (2-ethylhexyl) phthalate (DEHP) in kidney tissue of rats and human embryonic kidney (HEK) 293 cell line. The HEK-293 cells were treated with different concentrations of quercetin 24 h before treatment with monoethylhexyl phthalate (MEHP). Male rats were treated with 200-mg/kg DEHP, 200-mg/kg DEHP plus quercetin (50 and 100 mg/kg), and 200-mg/kg DEHP plus vitamin E (20 mg/kg) for 45 days by gavage. Quercetin treatment reduced cytotoxicity and oxidative damage inducing by MEHP in HEK-293 cells. The in vivo findings showed that 100-mg/kg quercetin significantly suppressed DEHP-induced kidney damage. For exploring the involved mechanisms, the expressions of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), nuclear factor kappa B (NFκB), and tumor necrosis factor alpha (TNFα) genes were determined via real-time Polymerase chain reaction (PCR) assay. High dose of quercetin significantly decreased the gene expressions of NF-κB and TNFα, whereas the alternations of Nrf2 and HO-1 gene expressions were not significant in quercetin groups in compared with DEHP group. These findings suggested that the suppression of DEHP-induced nephrotoxicity via quercetin is correlated, at least in part, with its potential to regulate NF-κB signaling pathway.

Ameliorate impacts of scopoletin against vancomycin-induced intoxication in rat model through modulation of Keap1-Nrf2/HO-1 and IκBα-P65 NF-κB/P38 MAPK signaling pathways: Molecular study, molecular docking evidence and network pharmacology analysis

Nephrotoxicity is an indication for the damage of kidney-specific detoxification and excretion mechanisms by exogenous or endogenous toxicants. Exposure to vancomycin predominantly results in renal damage and losing the control of body homeostasis. Vancomycin-treated rats (200 mg/kg/once daily, for seven consecutive days, i.p.) revealed significant increase in serum pivotal kidney function, oxidative stress, and inflammatory biomarkers. Histologically, vancomycin showed diffuse acute tubular necrosis, denudation of epithelium and infiltration of inflammatory cells in the lining tubular epithelium in cortical portion. In the existing study, the conservative consequences of scopoletin against vancomycin nephrotoxicity was investigated centering on its capacity to alleviate oxidative strain and inflammation through streamlining nuclear factor (erythroid-derived-2) like 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling and prohibiting the nuclear factor kappa B (NF-κB)/mitogen-activated protein kinase (p38 MAPK) pathway. With respect to vancomycin group, scopoletin pretreatment (50 mg/kg/once daily, i.p.) efficiently reduced kidney function, oxidative stress biomarkers and inflammatory mediators. Moreover, histological and immunohistochemical examination of scopoletin-treated group showed remarkable improvement in histological structure and reduced vancomycin-induced renal expression of iNOS, NF-κB and p38 MAPK. In addition, scopoletin downregulated (Kelch Like ECH Associated Protein1) Keap1, P38MAPK and NF-κB expression levels while upregulated renal expression levels of regulatory protein (IκBα), Nrf2 and HO-1. Furthermore, molecular docking and network approach were constructed to study the prospect interaction between scopoletin and the targeted proteins that streamline oxidative stress and inflammatory pathways. The present investigations elucidated that scopoletin co-treatment with vancomycin may be a rational curative protocol for mitigation of vancomycin-induced renal intoxication.

Causal Association Between Tea Consumption and Kidney Function: A Mendelian Randomization Study

Background

Causal research concerning the consumption of tea and the risk of chronic kidney disease (CKD) is limited. This study identified the potential causal effects of tea intake on CKD, the estimated glomerular filtration rate (eGFR), and albuminuria.

Methods

Genome-wide association studies (GWASs) from UK Biobank were able to identify single-nucleotide polymorphisms (SNPs) associated with an extra cup of tea each day. The summary statistics for the kidney function from the CKDGen consortium include 11,765 participants (12,385 cases of CKD) and 54,116 participants for the urinary albumin-to-creatinine ratio who were mostly of European descent. A two-sample Mendelian randomization (MR) analysis was performed to test the relationship between the selected SNPs and the risk of CKD.

Results

A total of 2,672 SNPs associated with tea consumption (p < 5 × 10^-8) were found, 45 of which were independent and usable in CKDGen. Drinking more cups of tea per day indicates a protective effect for CKD G3-G5 [odds ratio (OR) = 0.803; p = 0.004] and increases eGFR (β = 0.019 log ml/min/1.73 m² per cup per day; p = 2.21 × 10^-5). Excluding two SNPs responsible for directional heterogeneity (Cochran Q p = 0.02), a high consumption of tea was also negatively correlated with a lower risk of albuminuria (OR = 0.758; p = 0.002).

Conclusion

From the perspective of genes, causal relationships exist between daily extra cup of tea and the reduced risk of CKD and albuminuria and increased eGFR.

Natural products: potential treatments for cisplatin-induced nephrotoxicity

Cisplatin is a clinically advanced and highly effective anticancer drug used in the treatment of a wide variety of malignancies, such as head and neck, lung, testis, ovary, breast cancer, etc. However, it has only a limited use in clinical practice due to its severe adverse effects, particularly nephrotoxicity; 20%–35% of patients develop acute kidney injury (AKI) after cisplatin administration. The nephrotoxic effect of cisplatin is cumulative and dose dependent and often necessitates dose reduction or withdrawal. Recurrent episodes of AKI result in impaired renal tubular function and acute renal failure, chronic kidney disease, uremia, and hypertensive nephropathy. The pathophysiology of cisplatin-induced AKI involves proximal tubular injury, apoptosis, oxidative stress, inflammation, and vascular injury in the kidneys. At present, there are no effective drugs or methods for cisplatin-induced kidney injury. Recent in vitro and in vivo studies show that numerous natural products (flavonoids, saponins, alkaloids, polysaccharide, phenylpropanoids, etc.) have specific antioxidant, anti-inflammatory, and anti-apoptotic properties that regulate the pathways associated with cisplatin-induced kidney damage. In this review we describe the molecular mechanisms of cisplatin-induced nephrotoxicity and summarize recent findings in the field of natural products that undermine these mechanisms to protect against cisplatin-induced kidney damage and provide potential strategies for AKI treatment.

Antioxidant and Anti-Inflammatory Effects of 3-Dehydroxyceanothetric Acid 2-Methyl Ester Isolated from Ziziphus jujuba Mill. against Cisplatin-Induced Kidney Epithelial Cell Death

Cisplatin is a platinum-based chemotherapeutic agent for treating solid tumors; however, it presents a risk factor for nephropathy. In the present study, we investigated the antioxidant and anti-inflammatory effects of 3-dehydroxyceanothetric acid 2-methyl ester (3DC2ME) isolated from Ziziphus jujuba Mill. in LLC-PK1 cells following cisplatin-induced cytotoxicity. These cells were exposed to 3DC2ME for 2 h, followed by treatment with cisplatin for 24 h. The treated cells were subjected to cell viability analysis using the Ez-Cytox assay. Reactive oxygen species (ROS) were detected via 2', 7'- dichlorodihydrofluorescein diacetate (DCFH-DA) staining. In addition, western blotting and fluorescent immunostaining were performed to evaluate protein expressions related to oxidative stress and inflammation pathways. Pretreatment with 3DC2ME protected LLC-PK1 cells from cisplatin-induced cytotoxicity and oxidative stress. In addition, pretreatment with 3DC2ME upregulated heme oxygenase 1 (HO-1) via the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in the cisplatin-treated LLC-PK1 cells. Furthermore, the increase in the expressions of IκB kinase α/β (IKKα/β), inhibitor of kappa B alpha (IκBα), nuclear factor kappa B (NF-κB), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in these cells was inhibited. These results provide basic scientific evidence for understanding the antioxidant and anti-inflammatory effects of 3DC2ME isolated from Z. jujuba against cisplatin-induced kidney epithelial cell death.

NRF2 activation inhibits valproic acid-induced neural tube defects in mice

Valproic acid (VPA) is a widely prescribed medication that has traditionally been used to treat epilepsy, yet embryonic exposure to VPA increases the risk of the fetus developing neural tube defects (NTDs). While the mechanism by which VPA causes NTDs is unknown, we hypothesize that VPA causes dysmorphogenesis through the disruption of redox-sensitive signaling pathways that are critical for proper embryonic development, and that protection from the redox disruption may decrease the prevalence of NTDs. Time-bred CD-1 mice were treated with 3H-1,2-dithiole-3-thione (D3T), an inducer of nuclear factor erythroid 2-related factor 2 (NRF2)-a transcription factor that activates the intracellular antioxidant response to prevent redox disruptions. Embryos were then collected for whole embryo culture and subsequently treated with VPA in vitro. The glutathione (GSH)/glutathione disulfide (GSSG) redox potential (E_h), a measure of the intracellular redox environment, was measured in the developing mouse embryos. Embryos treated with VPA exhibited a transiently oxidizing GSH/GSSG E_h, while those that received D3T pretreatment prior to VPA exposure showed no differences compared to controls. Moving to an in utero mouse model, time-bred C57BL/6 J dams were pretreated with or without D3T and then exposed to VPA, after which all embryos were collected for morphological analyses. The prevalence of open neural tubes in embryos treated with VPA significantly decreased with D3T pretreatment, as did the severity of the observed defects evaluated by a morphological assessment. These data show that NRF2 induction via D3T pretreatment protects against VPA-induced redox dysregulation and decreases the prevalence of NTDs in developing mouse embryos.

Modulation of inflammation by phytochemicals to enhance efficacy and reduce toxicity of cancer chemotherapy

Treatment of cancer with chemotherapeutic drugs is associated with numerous adverse effects as well as the eventual development of resistance to chemotherapy. There is a great need for complementary therapies such as botanicals and nutritional supplements with little or no side effects that prevent resistance to chemotherapy and reduce its adverse effects. Inflammation plays a major role in the development of chemoresistance and the adverse effects of chemotherapy. Phytochemicals have well-established anti-inflammatory effects; thus, they could be used as complementary therapies along with chemotherapy to increase its efficacy and reduce its toxicity. Botanical compounds inhibit the NF-κB signaling pathway, which plays an important role in the generation of inflammation, chemotherapy resistance, and modulation of cell survival and apoptosis. Botanicals have previously been studied extensively for their cancer chemopreventive activities and are generally considered safe for human consumption. The present review focuses on the modulation of inflammation by phytochemicals and their role in increasing the efficacy and reducing the toxicity of cancer chemotherapy.

The Multifaceted Role of Flavonoids in Cancer Therapy: Leveraging Autophagy with a Double-Edged Sword

Flavonoids are considered as pleiotropic, safe, and readily obtainable molecules. A large number of recent studies have proposed that flavonoids have potential in the treatment of tumors by the modulation of autophagy. In many cases, flavonoids suppress cancer by stimulating excessive autophagy or impairing autophagy flux especially in apoptosis-resistant cancer cells. However, the anti-cancer activity of flavonoids may be attenuated due to the simultaneous induction of protective autophagy. Notably, flavonoids-triggered protective autophagy is becoming a trend for preventing cancer in the clinical setting or for protecting patients from conventional therapeutic side effects in normal tissues. In this review, focusing on the underlying autophagic mechanisms of flavonoids, we hope to provide a new perspective for clinical application of flavonoids in cancer therapy. In addition, we highlight new research ideas for the development of new dosage forms of flavonoids to improve their various pharmacological effects, establishing flavonoids as ideal candidates for cancer prevention and therapy in the clinic.

Nrf2 signaling pathway in cisplatin chemotherapy: Potential involvement in organ protection and chemoresistance

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor and its induction is of significant importance for protecting against oxidative damage. Increased levels of Reactive Oxygen Species (ROS) stimulate Nrf2 signaling, enhancing the activity of antioxidant enzymes such as catalase, superoxide dismutase and glutathione peroxidase. These enzymes are associated with retarding oxidative stress. On the other hand, Nrf2 activation in cancer cells is responsible for the development of chemoresistance due to disrupting oxidative mediated-cell death by reducing ROS levels. Cisplatin (CP), cis-diamminedichloroplatinum(II), is a potent anti-tumor agent extensively used in cancer therapy, but its frequent application leads to the development of chemoresistance as well. In the present study, association of Nrf2 signaling with chemoresistance to CP and protection against its deleterious effects is discussed. Anti-tumor compounds, mainly phytochemicals, retard chemoresistance by suppressing Nrf2 signaling. Upstream mediators such as microRNAs can regulate Nrf2 expression during CP chemotherapy regimens. Protection against side effects of CP is mediated via activating Nrf2 signaling and its downstream targets activating antioxidant defense system. Protective agents that activate Nrf2 signaling, can ameliorate CP-mediated ototoxicity, nephrotoxicity and neurotoxicity. Reducing ROS levels and preventing cell death are the most important factors involved in alleviating CP toxicity upon Nrf2 activation. As pre-clinical experiments advocate the role of Nrf2 in chemoprotection and CP resistance, translating these findings to the clinic can provide a significant progress in treatment of cancer patients.

Catalytic activity tunable ceria nanoparticles prevent chemotherapy-induced acute kidney injury without interference with chemotherapeutics

Acute kidney injury (AKI) is a prevalent and lethal adverse event that severely affects cancer patients receiving chemotherapy. It is correlated with the collateral damage to renal cells caused by reactive oxygen species (ROS). Currently, ROS management is a practical strategy that can reduce the risk of chemotherapy-related AKI, but at the cost of chemotherapeutic efficacy. Herein, we report catalytic activity tunable ceria nanoparticles (CNPs) that can prevent chemotherapy-induced AKI without interference with chemotherapeutic agents. Specifically, in the renal cortex, CNPs exhibit catalytic activity that decomposes hydrogen peroxide, and subsequently regulate the ROS-involved genes by activating the Nrf2/Keap1 signaling pathway. These restore the redox homeostasis for the protection of kidney tubules. Under an acidic tumor microenvironment, CNPs become inert due to the excessive H+ that disrupts the re-exposure of active catalytic sites, allowing a buildup of chemotherapy-mediated ROS generation to kill cancer cells. As ROS-modulating agents, CNPs incorporated with context-dependent catalytic activity, hold a great potential for clinical prevention and treatment of AKI in cancer patients.

New Spirocyclic Hydroxamic Acids as Effective Antiproliferative Agents

AIMS

The main goal of this work is to synthesize new original spirocyclic hydroxamic acids, investigate their cytotoxicity against the panel of tumor cell lines and possible mechanism of action of these active compounds.

BACKGROUND

Hydroxamic acids are one of the promising classes of chemical compounds with proven potential anticancer properties. This is manifested in the presence of metal chelating and antioxidant activities, the ability to inhibit histone deacetylase enzymes and a chemosensitizing effect against well known cytostatics.

OBJECTIVE

Original spirocyclic hydroxamic acids were synthesized and spectra of their antiproliferative activities were investigated.

METHODS

The cytotoxic activities on different tumor lines (SH-SY5Y, HeLa and healthy cells HEK-293) were investigated and determined possible underlying mechanisms of their activity.

RESULTS

New original spirocyclic hydroxamic acids were synthesized. These compounds exhibit antiproliferative properties against various tumor cultures cells and also exhibit antioxidant activity, a depolarizing effect on the mitochondrial membrane, inhibit the activity of the histone deacetylase enzyme, and also decrease of basal glycolysis and glycolytic capacity reserve of HeLa and SH-SY5Y tumor cell lines.

CONCLUSION

The most promising are compounds 5j-l containing two chlorine atoms as substituents in the quinazoline part of the molecule and hydroxamate function. Therefore, these compounds can be considered as hit compounds for the development on their basis multi-target anticancer agents.

New insights into the role of the Nrf2 signaling pathway in green tea catechin applications

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a transcriptional signaling pathway that plays a crucial role in numerous clinical complications. Pivotal roles of Nrf2 have been proved in cancer, autoimmune diseases, neurodegeneration, cardiovascular diseases, diabetes mellitus, renal injuries, respiratory conditions, gastrointestinal disturbances, and general disorders related to oxidative stress, inflammation, apoptosis, gelatinolysis, autophagy, and fibrogenesis processes. Green tea catechins as a rich source of phenolic compounds can deal with various clinical problems and manifestations. In this review, we attempted to focus on intervention between green tea catechins and Nrf2. Green tea catechins especially epigallocatechin gallate (EGCG) elucidated the protective role of Nrf2 and its downstream molecules in various disorders through Keap-1, HO-1, NQO-1, GPx, GCLc, GCLm, NF-kB cross-link, kinases, and apoptotic proteins. Subsequently, we compiled an updated expansions of the Nrf2 role as a gate to manage and protect different disorders and feasible indications of green tea catechins through this signaling pathway. The present review highlighted recent evidence-based data in silico, in vitro, and in vivo studies on an outline for future clinical trials.

Comprehensive Review of Methodology to Detect Reactive Oxygen Species (ROS) in Mammalian Species and Establish Its Relationship with Antioxidants and Cancer

Evidence suggests that reactive oxygen species (ROS) mediate tissue homeostasis, cellular signaling, differentiation, and survival. ROS and antioxidants exert both beneficial and harmful effects on cancer. ROS at different concentrations exhibit different functions. This creates necessity to understand the relation between ROS, antioxidants, and cancer, and methods for detection of ROS. This review highlights various sources and types of ROS, their tumorigenic and tumor prevention effects; types of antioxidants, their tumorigenic and tumor prevention effects; and abnormal ROS detoxification in cancer; and methods to measure ROS. We conclude that improving genetic screening methods and bringing higher clarity in determination of enzymatic pathways and scale-up in cancer models profiling, using omics technology, would support in-depth understanding of antioxidant pathways and ROS complexities. Although numerous methods for ROS detection are developing very rapidly, yet further modifications are required to minimize the limitations associated with currently available methods.

Protection against chemotherapy- and radiotherapy-induced side effects: A review based on the mechanisms and therapeutic opportunities of phytochemicals

BACKGROUND

Although great achievements have been made in the field of cancer therapy, chemotherapy and radiotherapy remain the mainstay cancer therapeutic modalities. However, they are associated with various side effects, including cardiocytotoxicity, nephrotoxicity, myelosuppression, neurotoxicity, hepatotoxicity, gastrointestinal toxicity, mucositis, and alopecia, which severely affect the quality of life of cancer patients. Plants harbor a great chemical diversity and flexible biological properties that are well-compatible with their use as adjuvant therapy in reducing the side effects of cancer therapy.

PURPOSE

This review aimed to comprehensively summarize the molecular mechanisms by which phytochemicals ameliorate the side effects of cancer therapies and their potential clinical applications.

METHODS

We obtained information from PubMed, Science Direct, Web of Science, and Google scholar, and introduced the molecular mechanisms by which chemotherapeutic drugs and irradiation induce toxic side effects. Accordingly, we summarized the underlying mechanisms of representative phytochemicals in reducing these side effects.

RESULTS

Representative phytochemicals exhibit a great potential in reducing the side effects of chemotherapy and radiotherapy due to their broad range of biological activities, including antioxidation, antimutagenesis, anti-inflammation, myeloprotection, and immunomodulation. However, since a majority of the phytochemicals have only been subjected to preclinical studies, clinical trials are imperative to comprehensively evaluate their therapeutic values.

CONCLUSION

This review highlights that phytochemicals have interesting properties in relieving the side effects of chemotherapy and radiotherapy. Future studies are required to explore the clinical benefits of these phytochemicals for exploitation in chemotherapy and radiotherapy.

A Novel Antioxidant Protects Against Contrast Medium-Induced Acute Kidney Injury in Rats

Many studies proposed that oxidative stress and apoptosis are key mechanisms in the pathogenesis of contrast-induced acute kidney injury (CI-AKI). Xylose-pyrogallol conjugate (XP) is an original effective antioxidant that showed decent antioxidant and anti-apoptosis effect before. Thus the therapeutic effect and mechanism of XP in preventing CI-AKI in the short and long term were investigated in this research. Renal function and histological grade were evaluated to determine the severity of renal injury. Kidney samples were then collected for the measurement of oxidative stress markers and the detection of apoptosis. Transmission electron microscopy (TEM) and western blot of mitochondrial protein were utilized for the analysis of the mitochondrial conditions. The results demonstrated that the CI-AKI rats caused a significant decrease in renal function accompanied by a remarkable increase in Malondialdehyde (MDA), bax, caspase-3, cytochrome c (Cyt C) level, TdT-mediated dUTP nick end labeling (TUNEL) positive apoptotic cells, and damaged mitochondria, while a decline in antioxidase activities and mitochondrial superoxide dismutase 2 (SOD2) expression compared with the control rats. However, when XP (50 or 100 or 200 mg/kg/day) was given orally for consecutive 7 days before CI-AKI modeling, XP (200 mg/kg) showed a better capability to restore renal dysfunction, histopathological appearance, the level of apoptosis, mitochondrial damage, oxidative stress, and fibrosis generation without interference in computed tomographic imaging. Our study indicated that antioxidant XP played a nephroprotective role probably via antiapoptotic and antioxidant mechanisms. Besides, XP may regulate the mitochondria pathway via decreasing the ratio of bax/bcl-2, inhibiting caspase-3 expression, cytochrome c release, and superoxide dismutase 2 activity. Overall, XP as a high-efficient antioxidant may have the potentials to prevent CI-AKI.

Epigallocatechin gallate diminishes cigarette smoke-induced oxidative stress, lipid peroxidation, and inflammation in human bronchial epithelial cells

Cigarette smoke (CS), the major risk factor of chronic obstructive pulmonary disease (COPD), contains numerous free radicals that can cause oxidative stress and exaggerated inflammatory responses in the respiratory system. Lipid peroxidation which is oxidative degradation of polyunsaturated fatty acids and results in cell damage has also been associated with COPD pathogenesis. Increased levels of lipid peroxidation as well as its end product 4-hydroxynonenal have indeed been detected in COPD patients. Additionally, reactive oxygen species such as those contained in CS can activate nuclear factor-κB signaling pathway, initiating cascades of proinflammatory mediator expression. As emerging evidence attests to the antioxidative and anti-inflammatory properties of tea catechins, we sought to determine whether epigallocatechin gallate, the most abundant tea catechin, can provide protection against oxidative stress, lipid peroxidation, and inflammatory responses caused by CS. We found that EGCG treatment blocked cigarette smoke extract (CSE)-induced oxidative stress as indicated by decreased production and accumulation of reactive oxygen species in airway epithelial cells (AECs). Likewise, lipid peroxidation in CSE-stimulated AECs was suppressed by EGCG. Our findings further suggest that EGCG sequestered 4-hydroxynonenal and interfered with its protein adduct formation. Lastly, we show that EGCG inhibited nuclear factor-κB activation and the downstream expression of proinflammatory mediators. In summary, our study describing the antioxidative and anti-inflammatory effects of EGCG in CSE-exposed AECs provide valuable information about the therapeutic potential of this tea catechin for COPD.

Increases of iASPP-Keap1 interaction mediated by syringin enhance synaptic plasticity and rescue cognitive impairments via stabilizing Nrf2 in Alzheimer's models

Oxidative stress is an important pathogenic manifestation of Alzheimer's disease (AD) that contributes to synaptic dysfunction, which precedes Aβ accumulation and neurofibrillary tangle formation. However, the molecular machineries that govern the decline of antioxidative defence in AD remains to be elucidated, and effective candidate for AD treatment is limited. Here, we showed that the decreases in the inhibitor of apoptosis-stimulating protein of p53 (iASPP) was associated with the vulnerability to oxidative stress in the amyloid precursor protein (APP)/presenilin 1 (PS1) mouse brain. Treatment with an antioxidant, syringin, could ameliorate AD-related pathologic and behavioural impairments. Interestingly, syringin treatment resulted in an upregulation of iASPP and the increase in the interaction of iASPP with Kelchlike ECH-associating protein 1 (Keap1). Syringin reduced neuronal apoptosis independently of p53. We confirmed that syringin-induced enhancement of antioxidant defenses involved the stabilization of Nrf2 in overexpressing human Swedish mutant APP (APPswe) cells in vitro. Syringin-mediated Nrf2 nuclear translocation facilitated the activation of the Nrf2 downstream genes via iASPP/Nrf2 axis. Our results demonstrate that syringin-mediated increases of iASPP-Keap1 interaction restore cellular redox balance. Further study on the syringin-iASPP interactions may help in understanding the regulatory mechanism and designing novel potent modulators for AD treatment.

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Poor expression of iASPP is associated with the serious accumulation of β-amyloid.

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Syringin reduces Aβ production and mitigates cognitive deficits by amending redox.

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Syringin-caused increases of iASPP facilitate the activation of NADPH and γGCL-C.

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Syringin protects neuronal cells against oxidative stress via iASPP/Nrf2 axis.

Naturally Derived Heme-Oxygenase 1 Inducers and Their Therapeutic Application to Immune-Mediated Diseases

Heme oxygenase (HO) is the primary antioxidant enzyme involved in heme group degradation. A variety of stimuli triggers the expression of the inducible HO-1 isoform, which is modulated by its substrate and cellular stressors. A major anti-inflammatory role has been assigned to the HO-1 activity. Therefore, in recent years HO-1 induction has been employed as an approach to treating several disorders displaying some immune alterations components, such as exacerbated inflammation or self-reactivity. Many natural compounds have shown to be effective inductors of HO-1 without cytotoxic effects; among them, most are chemicals present in plants used as food, flavoring, and medicine. Here we discuss some naturally derived compounds involved in HO-1 induction, their impact in the immune response modulation, and the beneficial effect in diverse autoimmune disorders. We conclude that the use of some compounds from natural sources able to induce HO-1 is an attractive lifestyle toward promoting human health. This review opens a new outlook on the investigation of naturally derived HO-1 inducers, mainly concerning autoimmunity.

Tadalafil alleviates cisplatin-induced reproductive toxicity through the activation of the Nrf2/HO-1 pathway and the inhibition of oxidative stress and apoptosis in male rats

Male reproductive toxicity is a well-known adverse effect of cisplatin (CIS), an important antineoplastic agent used to control several types of cancers. Tadalafil (TDF), is a long-acting phosphodiesterase-5 (PDE5) inhibitor commonly used as treatment for erectile dysfunction. The aim of this work was to study the possible protective effect of TDF against CIS-induced testicular toxicity in rats and the possible involvement of Nrf2/HO-1 pathway, which demonstrates antioxidant and inflammatory activities utilizing zinc protoporphyrin-IX (ZnPP) as HO-1 inhibitor. Results revealed that TDF attenuated the CIS-induced disturbances in sperm count and activities, normalized the serum testosterone level, improved the CIS-induced changes in epididymal and testicular weights and restored the normal structure of testicular tissues. In addition, TDF upregulated the gene expression levels of Nrf2 and HO-1 and the activity of HO-1 whereas, it reduced the CIS-induced changes in testicular oxidative stress markers and the levels of inflammatory mediators (TNF-α and iNOS). Furthermore, TDF antagonized the CIS-induced increase in testicular gene expression of apoptotic markers caspase-3 and Bax, and the decrease in Bcl-2. However, ZnPP co-administration significantly attenuated all TDF-mediated improvements in CIS-induced testicular toxicity, biochemical changes, and apoptosis. In conclusion, TDF exerts a protective effect against CIS-induced reproductive toxicity in males, through different mechanisms, besides its inhibitory action to PDE5, possibly mediated by the upregulation of Nrf2/HO-1, along with its antioxidant, anti-inflammatory, and anti-apoptotic effects. Hence, the use of TDF represents a promising therapeutic approach to protect the male reproductive system from the harmful toxic effects of CIS.

Interventions of natural and synthetic agents in inflammatory bowel disease, modulation of nitric oxide pathways

Inflammatory bowel disease (IBD) refers to a group of disorders characterized by chronic inflammation of the gastrointestinal (GI) tract. The elevated levels of nitric oxide (NO) in serum and affected tissues; mainly synthesized by the inducible nitric oxide synthase (iNOS) enzyme; can exacerbate GI inflammation and is one of the major biomarkers of GI inflammation. Various natural and synthetic agents are able to ameliorate GI inflammation and decrease iNOS expression to the extent comparable with some IBD drugs. Thereby, the purpose of this study was to gather a list of natural or synthetic mediators capable of modulating IBD through the NO pathway. Electronic databases including Google Scholar and PubMed were searched from 1980 to May 2018. We found that polyphenols and particularly flavonoids are able to markedly attenuate NO production and iNOS expression through the nuclear factor κB (NF-κB) and JAK/STAT signaling pathways. Prebiotics and probiotics can also alter the GI microbiota and reduce NO expression in IBD models through a broad array of mechanisms. A number of synthetic molecules have been found to suppress NO expression either dependent on the NF-κB signaling pathway (i.e., dexamethasone, pioglitazone, tropisetron) or independent from this pathway (i.e., nicotine, prednisolone, celecoxib, β-adrenoceptor antagonists). Co-administration of natural and synthetic agents can affect the tissue level of NO and may improve IBD symptoms mainly by modulating the Toll like receptor-4 and NF-κB signaling pathways.

The effect of monotropein on alleviating cisplatin-induced acute kidney injury by inhibiting oxidative damage, inflammation and apoptosis

Although cisplatin is a common drug in the treatment of malignant tumors, its clinical application is limited due to various side effects, especially acute kidney injury (AKI). Till now, few effective pharmacological strategies can be applied to inhibit cisplatin-induced AKI. Here, we aimed to investigate the protective effects and possible mechanisms of monotropein on cisplatin-induced AKI. In this study, an AKI model was established in cisplatin-treated mice, and serum level of inflammatory cytokines, protein expressions of biochemical indicators and renal pathology were analyzed. Our results showed that our results showed that monotropein could significantly attenuate cisplatin-induced nephrotoxicity and reduce the levels of blood urea nitrogen (BUN) and serum creatinine (CRE). Furthermore, monotropein inhibited cisplatin-induced oxidative stress by reducing MDA level and increasing the activities of GSH, SOD and CAT. The underlying mechanisms of monotropein on alleviating cisplatin-induced AKI were associated with the activation of Nrf2/HO-1 pathway against oxidative stress and the inhibition on NF-κB signaling to suppress inflammation as well as the regulation on the expressions of proteins in apoptosis pathway in this renal injury model. This study firstly provided the evidence that monotropein could significantly attenuate cisplatin-induced AKI and suggested that monotropein might be used as a potential agent to alleviate side effects of cisplatin.

Kaempferol ameliorates Cisplatin induced nephrotoxicity by modulating oxidative stress, inflammation and apoptosis via ERK and NF-κB pathways

Anticancer drug like Cisplatin are associated with serious problem like nephrotoxicity. The effect of Kaempferol is a plant-derived flavonoid compound. The present work evaluated the effect of Kaempferol in mouse model of Cisplatin mediated nephrotoxicity also the involved mechanism. Oxidative stress, kidney function, histology, inflammation, apoptosis, level of proteins, Nrf2 translocation and its effect on cascades such as NF-κB and ERK were studied. It was observed that the pre-treatment of KPF reduced the Cisplatin mediated oxidative stress, inflammation, apoptosis and ameliorated renal injury and its functioning. Kaempferol suppressed the Cisplatin induced infiltration of mononuclear cells, levels of TNF-α, iNOS, IL-12, activation of NF-κB, phosphorylation of IκBα and nuclear translocation of p65 in renal tissues. Also KPF attenuated Cisplatin mediated phosphorylation of p38, ERK1/2 and JNK in renal tissues. KPF also corrected the levels of renal antioxidants and elevated the nuclear levels of HO-1 and Nrf2 in renal tissues. KPF attenuated the Cisplatin mediated apoptosis via down-regulating the levels of TP53, Bax/Bcl2 imbalance, activating caspase-3/9 and PARP. The outcomes conclude that KPF ameliorates Cisplatin-mediated nephrotoxicity by modulating oxidative stress, inflammation and apoptosis via ERK and NF-κB pathway.

Dietary polyphenol impact on gut health and microbiota

Polyphenols are naturally occurring compounds in plants and they are the most abundant antioxidants in the human diet. Due to their considerable structural diversity, this largely influences their bioavailability. Since a large proportion of polyphenols remains unabsorbed along the gastrointestinal tract, they may accumulate in the large intestine, where most of them are extensively metabolized by the intestinal microbiota. The formation of bioactive polyphenol-derived metabolites may also benefit the health status of the subjects, although the mechanisms have not been delineated. This review aims to highlight the impact of polyphenols on gut health and the modes of action could be through modulation of intestinal barrier function, innate and adaptive immune response, signaling pathways, as well as the ability to modify gut microbiota composition. The review will conclude by presenting future perspective and challenges of polyphenols application in food products to be used for preventing or treating diseases.

Isoorientin Attenuates Cisplatin-Induced Nephrotoxicity Through the Inhibition of Oxidative Stress and Apoptosis via Activating the SIRT1/SIRT6/Nrf-2 Pathway

Cisplatin (CDDP) is a widely used chemotherapeutic agent for various solid tumors, but its severe side effects, particularly nephrotoxicity, limit its clinical application. Isoorientin (Iso) is a flavonoid-like compound known to have antioxidant effects. As oxidative injury plays a vital role in CDDP-induced acute kidney injury (AKI), the effect of Iso on CDDP-induced nephrotoxicity has not yet been researched. We assessed the effects of Iso against CDDP-induced nephrotoxicity in vitro using mTEC cells and further explored the mechanisms underlying CDDP-induced renal dysfunction in vivo in WT and Nrf2^-/- mice. The results showed that Iso treatment significantly reduced CDDP-induced nephrotoxicity via attenuating cell damage in vitro and via ameliorating renal injury, as determined by biochemical markers, in mice. The molecular mechanism underlying this protection was also investigated. Iso up-regulated the expression levels of SIRT1 and SIRT6 in vivo and in vitro. In addition, Iso activated Nrf2 translocation and the expression levels of its downstream antioxidant enzymes, such as HO-1 and NQO1, whereas it inhibited the expression level of NOX4, thus decreasing oxidative stress. Notably, the protective effects of Iso observed in WT mice were completely abolished in Nrf2^-/- mice. Collectively, these data indicate that the protective effect of Iso on CDDP-induced nephrotoxicity by SIRT1- and SIRT6-mediated Nrf2 activation regulates oxidative stress, inflammation and apoptosis. The absence of Nrf2 exacerbates CDDP-induced renal damage, and the pharmacological activation of Nrf2 may represent a novel therapy to prevent kidney injury.

(-)-Epigallocatechin-3-gallate (EGCG) attenuates salt-induced hypertension and renal injury in Dahl salt-sensitive rats

Epigallocatechin-3-gallate (EGCG), a main active catechin in green tea, was reported to attenuate renal injury and hypertension. However, its effects on salt-induced hypertension and renal injury remain unclear. In the present study, we explored its effects on hypertension and renal damage in Dahl rats with salt-sensitive hypertension. We found that EGCG could lower blood pressure after 6 weeks of oral administration, reduce 24 h urine protein levels and decrease creatinine clearance, and attenuate renal fibrosis, indicating that it could attenuate hypertension by protecting against renal damage. Furthermore, we studied the renal protective mechanisms of EGCG, revealing that it could lower malondialdehyde levels, reduce the numbers of infiltrated macrophages and T cells, and induce the apoptosis of NRK-49F cells. Considering that the 67 kD laminin receptor (67LR) binds to EGCG, its role in EGCG-induced fibroblast apoptosis was also investigated. The results showed that an anti-67LR antibody partially abrogated the apoptosis-inducing effects of EGCG on NRK-49F cells. In summary, EGCG may attenuate renal damage and salt-sensitive hypertension via exerting anti-oxidant, anti-inflammatory, and apoptosis-inducing effects on fibroblasts; the last effect is partially mediated by 67LR, suggesting that EGCG represents a potential strategy for treating salt-sensitive hypertension.

Benzbromarone mitigates cisplatin nephrotoxicity involving enhanced peroxisome proliferator-activated receptor-alpha (PPAR-α) expression

AIM

Despite the great efficacy reported for cisplatin as a widely used chemotherapeutic agent, its clinical use is limited by the challenge of facing its serious side effect; nephrotoxicity. In this study, the effect of the benzbromarone on peroxisome proliferator-activated receptor-alpha (PPAR-α) was investigated against cisplatin nephrotoxicity.

MAIN METHODS

Rats were administered benzbromarone (10 mg/kg/day; p.o.) for 14 days, and cisplatin (6.5 mg/kg; i.p.) as a single dose on the 10th day. Blood and kidney tissue samples were collected for determination of kidney function, biochemical and molecular markers, as well as histopathological investigation.

KEY FINDINGS

Benzbromarone improved kidney function, that was evidenced by reduced serum creatinine and blood urea nitrogen to nearly the half, compared to the group administered cisplatin alone. The protein expression of PPAR-α was enhanced with benzbromarone treatment, along with a considerable suppression of oxidative stress as benzbromarone reduced mRNA expression of NADPH oxidase, while increased the anti-oxidant HO-1 protein expression associated with enhancing Nrf2. Besides, it displayed a marked anti-inflammatory effect involved suppression of p38 MAPK/NF-κB p65 signaling pathway and its downstream targets. Moreover, benzbromarone retarded apoptosis associated with reducing the pro-apoptotic (Bax) and enhancing the anti-apoptotic (Bcl-2) protein expressions. The protective effects of benzbromarone were also confirmed by histopathological results.

SIGNIFICANCE

Our data confirm the relation between PPAR-α, and the deleterious effects induced by cisplatin. It can also be suggested that enhancing PPAR-α expression by benzbromarone is a promising therapeutic approach that overcomes cisplatin nephrotoxicity, involving regulation of different signaling pathways: Nrf2/HO-1, p38 MAPK/NF-κB p65, and Bax/Bcl-2.

Green tea polyphenol epigallocatechin-3-gallate improves the antioxidant capacity of eggs

Dietary supplementation with EGCG led to an increase in egg antioxidant activity and antioxidant chemical substances, tryptophan and carotenoid. This may be associated with its increasing effect on the oxidative stress related regulators expression (P38MAPK, Nrf2 and HO-1).