Role of the KATP channel in the protective effect of nicorandil on cyclophosphamide-induced lung and testicular toxicity in rats

Mitigating cyclophosphamide-associated gonadotoxicity in male Wistar rats: exploring the therapeutic potential of hesperidin

Hesperidin, a bioactive flavanone glycoside prevalent in citrus fruits, with remarkable therapeutic properties stands out as a formidable defender against the debilitating reproductive toxicity associated with Cyclophosphamide (CYP) chemotherapy. This study explores the protective potential of hesperidin (HSP@100 mg/kg b.wt PO daily) against CYP-induced (@ 40 mg/kg b.wt IP once in a week) reproductive toxicity in male Wistar rats as several studies were documented on single dose toxicity of CYP. In this experiment, we chose multidosage drug effects, which are more relevant in chemotherapy. Twenty-four rats were divided into four groups: Group 1 (Control), group 2 (CYP-treated), group 3 (HSP-treated), and group 4 (CYP + HSP-treated) for 28 days. The experimental design included assessments of relative testicular weight, semen analysis, testosterone levels, oxidative stress markers, inflammatory cytokines, gross and histopathological changes, and immunohistochemical evaluation. The results revealed that the administration of CYP led to a significant reduction in testicular weight, sperm count, motility, and testosterone levels, accompanied by increased oxidative stress and inflammatory response. Hesperidin co-administration demonstrated a protective effect by restoring these parameters to near-normal levels. Histopathological analysis revealed improved testicular architecture in the group 4 compared with the group 2. Oxidative stress indices indicated that hesperidin attenuated CYP-induced damage by reducing malondialdehyde levels, enhancing superoxide dismutase activity and maintaining glutathione levels. Similarly, inflammatory cytokine analysis demonstrated anti-inflammatory effects of hesperidin by reducing tumor necrosis factor-alpha (TNF-α) and elevating interleukin-10 (IL-10) levels in the group 4. Immunohistochemical evaluation of nuclear factor-kappa B (NF-κB) revealed increased inflammation in the CYP group, while hesperidin significantly reduced NF-κB expression, suggesting its anti-inflammatory properties.

Cyclophosphamide activates ferroptosis-induced dysfunction of Leydig cells via SMAD2 pathway†

Cyclophosphamide (CP) is a widely used chemotherapeutic drug and immunosuppressant in the clinic, and the hypoandrogenism caused by CP is receiving more attention. Some studies found that ferroptosis is a new mechanism of cell death closely related to chemotherapeutic drugs and plays a key role in regulating reproductive injuries. The purpose of this study is to explore ferroptosis' role in testicular Leydig cell dysfunction and molecular mechanisms relating to it. In this study, the level of ferroptosis in the mouse model of testicular Leydig cell dysfunction induced by CP was significantly increased and further affected testosterone synthesis. The ferroptosis inhibitors ferrostatin-1 (Fer-1) and iron chelator deferoxamine (DFO) can improve injury induced by CP. The results of immunohistochemistry showed that Fer-1 and DFO could improve the structural disorder of seminiferous tubules and the decrease of the number of Leydig cells in testicular tissue induced by CP. Immunofluorescence and western blot confirmed that Fer-1 and DFO could improve the expression of key enzymes in testosterone synthesis. The activation of SMAD family member 2 (Smad2)/cyclin-dependent kinase inhibitor 1A (Cdkn1a) pathway can improve the ferroptosis of Leydig cells induced by CP and protect the function of Leydig cells. By inhibiting the Smad2/Cdkn1a signal pathway, CP can regulate ferroptosis, resulting in testicular Leydig cell dysfunction. In this study, CP-induced hypoandrogenism is explained theoretically and a potential therapeutic strategy is provided.

Therapeutic potential of nicorandil beyond anti-anginal drug: A review on current and future perspectives

Nicorandil (NIC) is a well-known anti-anginal agent, which has been recommended as one of the second-line treatments for chronic stable angina as justified by the European guidelines. It shows an efficacy equivalent to that of classic anti-anginal agents. NIC has also been used clinically in various cardiovascular diseases such as variant or unstable angina and reperfusion-induced damage following coronary angioplasty or thrombolysis. Different mechanisms have been involved in the protective effects of nicorandil in various diseases, including opening of adenosine triphosphate-sensitive potassium (KATP) channel and donation of nitric oxide (NO). In recent years, NIC has been found to show numerous pharmacological activities such as neuroprotective, nephroprotective, hepatoprotective, cardioprotective, and testicular protective effects, among other beneficial effects on the body. The present review dwells on the pharmacological potentials of NIC beyond its anti-anginal action.

Levocetrizine attenuates cyclophosphamide-induced lung injury through inhibition of TNF-α, IL-1β, TGF-β and MMP-9

Cyclophosphamide (CP) is an antineoplastic drug commonly used worldwide. Despite its spread, it causes fatal organ toxicity. Lung toxicity is a serious side effect of CP. Actually, in the past three years the world has been facing an un-predicted crisis following COVID-19 pandemic and the associated high-mortality rates attributed to respiratory distress. Accordingly; this study aimed to probe the potential prophylactic role of levocetrizine against CP-induced lung injury. Animals were allocated into three sets; control; CP and CP/Levo. CP was intraperitoneally injected in rats 150 mg/kg once on day 7. Levocetrizine was given orally for 14 days starting 7 days before CP injection. On the last day, all rats were sacrificed and lung tissues were kept for analysis. CP significantly elevated lung/body weight index, inflammatory cell counts, LDH, total protein, TNF-α, IL-1β, TGF-β and histamine levels in bronchoalveolar lavage (BAL). Moreover, it markedly increased expression of MMP-9 and contents of MDA, hydroxyproline, collagen and NOx besides decreasing GSH level and SOD activity in lung tissues. These biochemical results were further confirmed by histopathological examination. In contrast, treatment with levocetrizine significantly attenuated CP-induced pathological alterations. These findings propose that levocetrizine can attenuate CP-induced lung injury via exerting antioxidant, anti-inflammatory and anti-fibrotic effects.

Exploring the role of ATP-sensitive potassium channel, eNOS, and P-glycoprotein in mediating the hepatoprotective activity of nicorandil in methotrexate-induced liver injury in rats

BACKGROUND

Methotrexate (MTX) is a commonly used chemotherapeutic agent; however, its clinical use is challenged by various types of injuries, including hepatotoxic side effects. Therefore, finding new protective drugs against MTX-induced toxicities is a critical need. Moreover, the different mechanisms mediating such effects are still not clear. The current study aimed to evaluate the possible ameliorative action of nicorandil (NIC) in MTX-induced hepatotoxicity and examine the roles of the ATP-sensitive potassium channel (KATP), endothelial nitric oxide synthase (eNOS), and P-glycoprotein (P-gp).

MATERIALS AND METHODS

Thirty-six male Wistar albino rats were used. NIC (3 mg/kg/day) was given orally for 2 weeks, and hepatotoxicity was induced by a single intraperitoneal injection of MTX (20 mg/kg) on the 11th day of the experiment. We confirmed the role of KATP by co-administering glimepiride (GP) (10 mg/kg/day) 30 min before NIC. The measured serum biomarkers were [alanine transaminase (ALT) and aspartate transaminase (AST)], total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NOx), tumor necrosis factor-alpha (TNFα), superoxide dismutase (SOD), and P-gp. Histopathology, eNOS, and caspase-3 immunoexpression were evaluated.

RESULTS

The MTX group displayed hepatotoxicity in the form of elevations of ALT, AST, MDA, NOx, and caspase-3 immunoexpression. Furthermore, the histopathological examination showed marked liver injury. TAC, SOD, P-gp, and eNOS immunoexpression showed significant inhibition. In the protective group, all parameters improved (P value < 0.05).

CONCLUSION

NIC has an ameliorative action against MTX-induced hepatotoxicity, most probably via its antioxidant, anti-inflammatory, and anti-apoptotic functions together with the modulation of the KATP channel, eNOS, and P-glycoprotein.

Protective effects of hesperidin in cyclophosphamide-induced parotid toxicity in rats

Cyclophosphamide (CYP) is an alkylating agent that is used on a wide range as a treatment of malignancies and autoimmune diseases. Previous studies have shown the promising role of hesperidin (HSP) as an antioxidant agent against various models of toxic agents. The protective effect of the HSP against CYP-induced parotid damage was evaluated in this study. Forty rats (180-200 g) were divided into four equal groups: Group I (received normal saline), Group II (HSP-treated at a dose of 100 mg/kg/day for 7 consecutive days), Group III (CYP-treated at a dose of 200 mg/kg single intraperitoneal injection on the 7th day of the experiment), Group IV (CYP + HSP); HSP-treated at a dose of 100 mg/kg/day for 7 consecutive days and CYP (200 mg/kg) single intraperitoneal injection on the 7th day of the experiment. Afterwards, the oxidative stress and inflammatory markers, the histopathological and immunohistochemical alterations of the parotid tissues in the studied groups were evaluated. CYP intoxication induced a significant parotid tissue injury represented by the elevation in the values of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and decrease in the catalase activity and glutathione peroxidase (GPx). Histologically, extensive histopathological alterations e.g., widely spaced serous acini with irregular shapes and congested blood vessels as well as downregulated ki-67 and alpha-smooth muscle actin (α-SMA) immunoexpression were induced by CYP. HSP administration markedly improved the biochemical and the histopathological studies. We can conclude that HSP elicited protective effects against the CYP-induced parotid toxicity.

Nicorandil mitigates amiodarone-induced pulmonary toxicity and fibrosis in association with the inhibition of lung TGF-β1/PI3K/Akt1-p/mTOR axis in rats

The long-term side effect of the antiarrhythmic drug, amiodarone (AMIO), such as lung toxicity, remains a critical clinical issue. The previous knowledge denotes diverse antioxidant, anti-inflammatory, and antifibrotic properties of the anti-anginal drug, nicorandil (NI). Therefore, we aimed to investigate the possible protective effect of NI on pulmonary tissue remodelling following AMIO-induced lung toxicity. The included rats were assigned into four equal groups (n = 8): (1) control, (2) control group that received NI 10 mg kg^-1  day^-1 , (3) model group that received AMIO in a dose of 60 mg kg^-1  day^-1 , and (4) treated group (AMIO-NI) that were treated with AMIO plus NI as shown above. Drug administration continued for 10 weeks. AMIO resulted in deteriorated (p < 0.001) pulmonary functions accompanied by respiratory acidosis. AMIO showed an obvious histological injury score with intense collagen deposition, disturbed nitric oxide synthase enzymes (NOS/iNOS), and increased alpha smooth muscle actin expression. Furthermore, AMIO upregulated the transforming growth factor (TGF-β1)/phosphoinositide-3 kinase (PI3K)-Akt1-p/mammalian target of rapamycin (mTOR) axis, which determined the possible mechanism of AMIO on pulmonary remodelling. NI treatment significantly (p < 0.001) prevented the AMIO-induced lung toxicity, as well as inhibited the TGF-β1/PI3K/Akt1-p/mTOR axis in the lung tissue of rats. The results were confirmed by an in-vitro study. CONCLUSION: The current results revealed that NI was effective in preserving the lung structure and functions. Amelioration of the oxidative stress and modulation of TGF-β1/PI3K/Akt1-p/mTOR have been achieved. This study suggests NI administration as a preventive therapy from the serious pulmonary fibrosis side effect of AMIO.

Integrative proteomics and metabolomics approach to identify the key roles of icariin-mediated protective effects against cyclophosphamide-induced spermatogenesis dysfunction in mice

The alkylating antineoplastic agent cyclophosphamide (CP) is known to be toxic to the male reproductive system, but there are no effective prevention or treatment options. The flavonoid icariin (ICA), which is used in Chinese medicine, has been shown to have a number of biological functions, including testicular protection. The current study looked into the protective effects of ICA in preventing CP-induced spermatogenesis dysfunction. The current study looked into the role of ICA in preventing testicular dysfunction caused by CP. For 5 days, healthy adult mice were given saline or a single dose of CP (50 mg/kg) intraperitoneally (i.p). For the next 30 days, mice were given ICA (80 mg/kg) by gavage. Animals were euthanized 12 h after receiving ICA, and testes were removed for biochemical, histopathological, sperm evaluation, and transmission electron microscope analysis (TEM). We also investigated the potential biological effects of ICA on CP-induced spermatogenesis dysfunction in mice using an integrated proteomic and metabolomic approach. The levels of 8309 proteins and 600 metabolites were measured. The majority of the differential proteins and metabolites were found to be enriched in a variety of metabolic pathways, including the PI3K-Akt signaling pathway, necroptosis, the mTOR signaling pathway, glycerophospholipid metabolism, and ABC transporters, implying that ICA may have molecular mechanisms that contribute to CP-induced spermatogenesis dysfunction in the testis. Taken together, these findings show that ICA effectively reduces testis injury, implying that ICA may have a role in male infertility preservation.

Cyclophosphamide-induced testicular oxidative-inflammatory injury is accompanied by altered immunosuppressive indoleamine 2, 3-dioxygenase in Wister rats: Influence of dietary quercetin

This study evaluated the role of quercetin against cyclophosphamide-induced distortion of rat testicular function. Adult rats were administered cyclophosphamide (100 mg/kg), quercetin (50 mg/kg) and in combination for seven days. Cyclophosphamide caused a significant increase in the activities of indoleamine 2, 3-dioxygenases (IDO), tryptophan 2, 3-dioxygenase (TDO), myeloperoxidase (MPO), and elevated the concentrations of interleukin 6 (IL-6) and interferon-γ (IFN-γ). Cyclophosphamide increased testis malondialdehyde (MDA) concentrations but depleted superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and glutathione (GSH). However, quercetin co-administration significantly (p < 0.05) prevented the increased values of IDO, TDO, MPO, IL-6, IFN-γ, MDA, SOD, CAT, GSH-Px and GSH compared with control rats. Also, quercetin co-treatment significantly increased serum testosterone, follicle-stimulating hormone (FSH), prolactin, luteinizing hormone (LH), activities of testicular 3β-hydroxysteroid dehydrogenase (3 β-HSD), 17β-hydroxysteroid dehydrogenase (17 β-HSD) as well as sperm count, motility and viability but reduced abnormal sperm morphology. Quercetin exposure alone did not alter any of the parameters evaluated relative to control. Thus, quercetin protected the testes against cyclophosphamide-induced alterations in immunosuppressive IDO/TDO activities elicited by oxidative-inflammatory mediators.

Nicorandil Inhibits Osteoclast Formation Base on NF-κB and p-38 MAPK Signaling Pathways and Relieves Ovariectomy-Induced Bone Loss

Osteolytic bone disorders are characterized by an overall reduction in bone mineral density which enhances bone ductility and vulnerability to fractures. This disorder is primarily associated with superabundant osteoclast formation and bone resorption activity. Nicorandil (NIC) is a vasodilatory anti-anginal drug with ATP-dependent potassium (KATP) channel openings. However, NIC is adopted to manage adverse cardiovascular and coronary events. Recent research has demonstrated that NIC also possesses anti-inflammatory peculiarity through the regulation of p38 MAPK and NF-κB signaling pathways. Both MAPK and NF-κB signaling pathways play pivotal roles in RANKL-induced osteoclast formation and bone resorption function. Herein, we hypothesized that NIC may exert potential biological effects against osteoclasts, and revealed that NIC dose-dependently suppressed bone marrow macrophage (BMM) precursors to differentiate into TRAP + multinucleated osteoclasts in vitro. Furthermore, osteoclast resorption assays demonstrated anti-resorptive effects exhibited by NIC. NIC had no impact on osteoblast differentiation or mineralization function. Based on Biochemical analyses, NIC relieved RANKL-induced ERK, NF-κB and p38 MAPK signaling without noticeable effects on JNK MAPK activation. However, the attenuation of NF-κB and p38 MAPK activation was sufficient to hamper the downstream induction of c-Fos and NFATc1 expression. Meanwhile, NIC administration markedly protected mice from ovariectomy (OVX)-induced bone loss through in vivo inhibition of osteoclast formation and bone resorption activity. Collectively, this work demonstrated the potential of NIC in the management of osteolytic bone disorders mediated by osteoclasts.

Hidrox® Counteracts Cyclophosphamide-Induced Male Infertility through NRF2 Pathways in a Mouse Model

BACKGROUND

Every year, men use cyclophosphamide to treat various cancers and autoimmune diseases. On the one hand, this chemotherapy often has the beneficial effect of regressing the tumor, but on the other hand, it leads to infertility due to excessive oxidative stress and apoptosis in the testes caused by its metabolite, acrolein.

METHODS

The objective of this study was to evaluate the beneficial power of a new compound called Hidrox^®, containing 40-50% hydroxytyrosol, in counteracting the damage related to fertility induced by cyclophosphamide. The study was conducted using a single intraperitoneal injection of cyclophosphamide at a dose of 200 mg/kg b.w, in distilled water at 10 mL/kg b.w. The treatment was administered via the oral administration of Hidrox^® at a dose of 50 mg/kg.

RESULTS

Our study confirms that the use of cyclophosphamide causes a series of sperm and histological alterations strongly connected with oxidative stress, lipid peroxidation, and apoptosis.

CONCLUSION

Our results demonstrate for the first time that Hidrox^® protects testes from CYP-induced alterations by the modulation of physiological antioxidant defenses.

Hypothesis: The potential therapeutic role of nicorandil in COVID-19

At present, there is yet no specific antiviral treatment or immunization against the newly identified human severe acute respiratory syndrome virus (SARS‐CoV2) that results in a rapidly progressive pandemic coronavirus disease 2019 (COVID‐19). We believe in a crucial need for a clinical strategy to counteract this viral pandemic based on the known pathogenesis throughout the disease course. Evidence suggests that exaggerated patient's inflammatory response and oxidative stress are likely to aggravate the disease pathology. The resulting endothelial dysfunction further induces fibrosis and coagulopathy. These disturbances can generate severe acute respiratory distress syndrome (ARDS) that can progress into respiratory and circulatory failure. Nicorandil is an anti‐anginal vasodilator drug acts by increasing nitric oxide bioavailability and opening of the K_ATP channel. Recently, nicorandil has been recognized to possess multiple protective effects against tissue injury. Here, we address a possible modulatory role of nicorandil against COVID‐19 pathogenesis. We hypothesise nicorandil would be an effective form of adjuvant therapy against COVID‐19.

A novel protective role of sacubitril/valsartan in cyclophosphamide induced lung injury in rats: impact of miRNA-150-3p on NF-κB/MAPK signaling trajectories

Cyclophosphamide (CP) is a chemotherapeutic agent that induces oxidative stress causing multiple organ damage. Sacubitril/valsartan, is a combined formulation of neprilysin inhibitor (sacubitril) and angiotensin II receptor blocker (valsartan), that induces the protective effect of brain natriuretic peptide. The aim of the current study is to investigate the prophylactic impacts of sacubitril/valsartan versus valsartan against CP-induced lung toxicity in rats. Rats were assigned randomly into 6 groups; control; received corn oil (2 ml/kg/day; p.o. for 6 days), sacubitril/valsartan (30 mg/kg; p.o. for 6 days), valsartan (15 mg/kg; p.o. for 6 days), CP (200 mg/kg; i.p. on day 5), sacubitril/valsartan + CP (30 mg/kg; p.o. for 6 days, 200 mg/kg; i.p. single dose on day 5, respectively), valsartan + CP (15 mg/kg; p.o. for 6 days, 200 mg/kg; i.p. single dose on day 5, respectively). Both sacubitril/valsartan and valsartan produced a significant decrease in the inflammation and fibrosis markers in the BALF, in comparison with the CP group. Both sacubitril/valsartan and valsartan produced an apparent decrease in the relative genes expression of miR-150-3p and NF-κB, as well as a significant decrease in the relative expression of P38 and ERK1/2 MAPKs and an increase in the relative gene expression of Nrf-2, compared to CP group. Intriguingly, sacubitril/valsartan , showed subtle superiority in almost all investigated parameters, compared to valsartan. In conclusion, sacubitril/valsartan effectively abrogated the CP induced lung inflammation and fibrosis, providing a potential promising protection that could be linked to their ability to inhibit miR-150-3p via inhibition of NF-κB and MAPK signaling pathways.

LCZ696 (sacubitril/valsartan) protects against cyclophosphamide-induced testicular toxicity in rats: Role of neprilysin inhibition and lncRNA TUG1 in ameliorating apoptosis

Cyclophosphamide (CP) is widely used as chemotherapy in various cancers; however, testicular atrophy has been encountered as an associated adverse effect. Oxidative stress, enhanced endoplasmic reticulum (ER) stress, and subsequent apoptosis are involved in the molecular mechanisms of CP-induced testicular toxicity. In addition to the cardiovascular benefits of LCZ696 (sacubitril/valsartan (VAL)), neprilysin inhibition was shown to mediate Ca²⁺ sequestration inside the ER. Furthermore, long noncoding RNA taurine-upregulated gene 1 (lncRNA TUG1) was shown to ameliorate apoptosis in various diseases. This tempted us to investigate the possible benefit of LCZ696 against CP-induced testicular dysfunction in rats through neprilysin inhibition axis, and the downstream apoptotic cascade, with highlighting the impact of lncRNA TUG1 in regulating testicular toxicity. Sixty adult male Wistar rats were randomly allocated as control, LCZ696, VAL, CP, CP + LCZ696, and CP + VAL. Testicular atrophy was induced by single-dose injection of CP (200 mg/kg; i.p.). LCZ696 treated group received LCZ696 (30 mg/kg; p.o.) for 6 days, with CP (200 mg/kg; i.p.) single-dose on day 5. LCZ696 increased lncRNA TUG1 expression, improved sperm characteristics, hormonal profile, testicular function, antioxidant defences, and Bcl-2. The histopathological picture and reduced oxidative and ER stress markers, aligned with declined Bax, caspase-3 and the expression of CHOP, PUMA, Noxa, Bim, and p53, with a subtle superior effect over VAL-treated group. In conclusion, the current study highlights the promising impact of LCZ696 in ameliorating chemotherapy-induced testicular atrophy; yet, further investigation regarding longer duration and different doses of LCZ696 is warranted.

Nicorandil: A drug with ongoing benefits and different mechanisms in various diseased conditions

Nicorandil is a well-known antianginal agent, which has been recommended as one of the second-line treatments for chronic stable angina as justified by the European guidelines. It shows an efficacy equivalent to that of classic antianginal agents. Nicorandil has also been applied clinically in various cardiovascular diseases such as variant or unstable angina and reperfusion-induced damage following coronary angioplasty or thrombolysis. Different mechanisms have been involved in the protective effects of nicorandil in various diseases through either opening of adenosine triphosphate-sensitive potassium (KATP) channel or donation of nitric oxide (NO). The predominance or participation of any of these proposed mechanisms depends on the dose of nicorandil used, the location of diseased conditions, and if this mechanism is still functioning or not. The protection afforded by nicorandil has been shown to be mainly attributed to KATP channel opening in experimental models of myocardial and pulmonary fibrosis as well as renal injury or glomerulonephritis, whereas NO donation predominates as a mechanism of protection in hepatic fibrosis and inflammatory bowel diseases. Therefore, in different diseased conditions, it is important to know which mechanism plays the major role in nicorandil-induced curative or protective effects. This can bring new insights into the proper use of selected medication and its recommended dose for targeting certain disease.

Protective effect of nicorandil on collapse‑induced lung injury in rabbits by inhibiting apoptosis

The one‑lung ventilation (OLV) technique is vital in thoracic surgery. However, it can result in severe lung injury, which is difficult to manage. The main solution at present is the use of ventilation strategies, including continuous positive oxygen pressure, low tidal volume and high frequency ventilation, and the administering of drugs, including phenylephrine, dexmedetomidine and morphine. However, the protective effect of these methods on the lungs is not sufficient to improve the prognosis of patients. Therefore, how to develop a novel protective drug remains an open question. Nicorandil, a mitochondrial (mito)KATP‑specific opener, serves an important role in cardioprotection, although its effect on lung injury remains unclear. The present study examined the protective role of nicorandil against collapse‑induced lung injury in rabbits undergoing OLV. Changes in arterial oxygen saturation (SaO2), arterial partial pressure for oxygen (PaO2), wet/dry weight ratio, and the microstructure of tissues and cells were observed. Enzyme‑linked immunosorbent assays were used to determine the concentrations of malondialdehyde (MDA) and tumor necrosis factor (TNF)‑α, and the activity of superoxide dismutase (SOD) in rabbits treated with nicorandil. Terminal deoxynucleotidyl transferase transfer‑mediated dUTP nick end‑labeling was used to detect apoptosis and western blotting was used to analyze the relative proteins involved in apoptosis. Western blotting and reverse transcription‑quantitative polymerase chain reaction analysis were used to examine the expression of hypoxia inducible factor 1α (HIF‑1α), phosphatidylinositol‑3‑kinase (PI3K), protein kinase B (Akt) and nuclear factor (NF)‑κB in the lungs of rabbits treated with nicorandil. The SaO2 and PaO2 in the high‑dose group were significantly higher than those in the control group in the process of OLV. The wet/dry weight ratio, and the concentrations of MDA and TNF‑α in the collapsed lung of the high‑dose group were significantly lower than those in the control group. The activity of SOD in the high‑dose group was significantly higher than that in the control group. The lung had improved microstructure and less apoptosis, which was determined by the Bax/Bcl2 ratio in the high‑dose group. The expression levels of PI3K, phosphorylated Akt and HIF‑1α were upregulated, whereas the expression of NF‑κB was downregulated. In conclusion, nicorandil had a protective effect via inhibiting apoptosis in non‑ventilated lung collapsed and re‑expansion during OLV in the rabbit. It acted on mitoKATP through the PI3K/Akt signaling pathway.

Nicorandil Attenuates LPS-Induced Acute Lung Injury by Pulmonary Endothelial Cell Protection via NF-κB and MAPK Pathways

Acute lung injury (ALI) is a devastating critical disease characterized by diffuse inflammation and endothelial dysfunction. Increasing evidence, including from our laboratory, has revealed that the opening of ATP-sensitive potassium (KATP) channels has promising anti-inflammation and endothelial protection activities in various disorders. However, the impacts of KATP channels on ALI remain obscure. In this study, we used nicorandil (Nico), a classic KATP channel opener, to investigate whether opening of KATP channels could alleviate ALI with an emphasis on human pulmonary artery endothelial cell (HPAEC) modulation. The results showed that Nico inhibited lipopolysaccharide- (LPS-) induced inflammatory response, protein accumulation, myeloperoxidase activity, and endothelial injury. In vitro, Nico reduced LPS-induced HPAEC apoptosis and the expression of cleaved-caspase-3, caspase-9, and CCAAT/enhancer-binding protein homologous protein (CHOP). Additionally, Nico inhibited inflammation by suppressing monocyte-endothelial adhesion and decreasing the expression of proinflammatory proteins. Moreover, Nico restored the expression and the distribution of adherens junction vascular endothelial- (VE-) cadherin. Further, Nico abolished the increase in intracellular reactive oxygen species (ROS) and the activation of NF-κB and mitogen-activated protein kinase (MAPK) in HPAECs. Glibenclamide (Gli), a nonselective KATP channel blocker, abrogated the effects of Nico, implying that opening of KATP channels contributes to the relief of ALI. Together, our findings indicated that Nico alleviated LPS-induced ALI by protecting ECs function via preventing apoptosis, suppressing endothelial inflammation and reducing oxidative stress, which may be attributed to the inhibition of NF-κB and MAPK signaling pathways.

Nicorandil ameliorates pulmonary inflammation and fibrosis in a rat model of silicosis

Nicorandil, an antianginal and potassium channel opener agent, has different useful impacts on cardiovascular and respiratory systems. Its effect against silicosis has not been discussed yet, therefore, this is an attempt to decide whether nicorandil can reduce silica-induced lung injury in rats. Silica model was induced by intranasal instillation of silica dust once. Rats were given nicorandil for 56 days after exposure to silica. Results showed that nicorandil significantly alleviated silica-induced inflammation as it decreased the elevated levels of total and differential cell counts, pulmonary edema (revealed by decreased lung/body weight ratio and W/D weight ratio), LDH and total protein levels in BALF. Notably, nicorandil decreased collagen deposition as evidenced by reduction in levels of hydroxyproline and collagen in lung tissues as well as obvious alleviation in silica-induced fibrosis in histopathological findings. Nicorandil effectively reduced the increased expression of NF-κB and iNOS and decreased MPO levels in lung tissues. Moreover, nicorandil abolished oxidative and nitrosative stress via reducing levels of pulmonary MDA and NOx concomitant with elevating levels of pulmonary GSH and SOD. Meanwhile, nicorandil decreased the levels of TNF-α and TGF-β, up regulated Nrf-2 and HO-1 levels in BALF suggesting antioxidant, anti-inflammatory and antifibrotic properties. In summary, nicorandil can confer protection against silica-induced lung inflammation and fibrosis. This impact might be due to its ability to down regulate the production of inflammatory and fibrotic cytokines in addition to restoring oxidant/antioxidant balance.

Role of venlafaxine in prevention of cyclophosphamide-induced lung toxicity and airway hyperactivity in rats

Cyclophosphamide (CP) is a drug used in chemotherapy and management of neoplastic diseases. This study aimed to investigate the prophylactic impacts of venlafaxine against CP-induced lung toxicity in rats. Rats were assigned randomly into 3 groups; control, CP (150 mg/kg) and CP/venlafaxine (50 mg/kg). On the end day, rats were sacrificed then bronchoalveolar fluid (BALF) and lungs were harvested. CP produced significant decrease in animal body weights and significant increase in lung/body weight ratio; levels of LDH, total protein, total and differential cell counts in BALF in comparison with control group. Moreover, significant elevation incontents of MDA, NOx, TNF-α and IL-1β and significant decline in GSH, SOD activities were observed in lung tissues. CP increased the response of tracheal zigzag to ACh. Histopathological results showed that CP increased inflammation and fibrosis in lung tissues. Venlafaxine restored most parameters to the normal levels. This protective effect of venlafaxine could be linked to its ability to reduce oxidative stress and inflammation.

GnRH Antagonist Improves Pubertal Cyclophosphamide-Induced Long-Term Testicular Injury in Adult Rats

BACKGROUND

Gonadal injury following chemotherapy is of increasing importance with the continuous improvement of survival rates. The protection of gonadotropin hormone antagonist (GnRHant) in long-term adult survivors of adolescent cancers and some autoimmune diseases has not yet been evaluated.

METHODS

The present study was aimed at longitudinally exploring whether the GnRHant could alleviate testicular damage induced by cyclophosphamide (CPA) in a rat model. Pubertal male rats were assigned to receive CPA with and without GnRHant. CPA was administrated at a single dose (100 mg/kg). GnRHant was started one hour prior to CPA injection and continued for four weeks (0.1 mg/kg, 3 times a week). Body and testes weights, testicular hormones, histological changes, and expression of androgen receptor (AR) in the testis were analyzed when rats matured into adulthood and completed a round of spermatogenesis.

RESULTS

Our results showed that body weight, histological injury, and AR expression in the testis were improved in the GnRHant + CPA group. However, testes weight and testicular hormones (anti-Müllerian hormone, inhibin B, and testosterone) did not markedly change.

CONCLUSION

Our results indicate that the GnRHant administration before and after CPA in pubertal rats can protect long-term testicular injury induced by CPA via increased AR expression in the testes.

Carvacrol attenuates cyclophosphamide-induced oxidative stress in rat kidney

Cyclophosphamide (CP) is an antineoplastic drug that induces kidney damage via producing oxidative stress. Carvacrol (CAR) has antioxidative effect and we postulated that it can be protective against CP-induced nephrotoxicity. Six groups (n = 7) of rats (control, 100 mg/kg CP, CP+5 mg/kg CAR, CP+10 mg/kg CAR, 5 mg/kg CAR, and 10 mg/kg CAR) were injected intraperitoneally. Serum malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), creatinine (CRE), total antioxidant capacity (TAC), and total oxidant state (TOS) were measured, and oxidative stress indexes (OSI) were calculated. Kidneys were also analyzed histologically. In CP-alone group MDA, CRE, TOS, and OSI levels increased whereas GSH, SOD, CAT, and TAC levels decreased compared with control group. In CP plus CAR groups, MDA, TOS, and OSI levels decreased whereas GSH, SOD, CAT, and TAC levels increased compared with CP-alone group. However, CRE levels were similar in CP-alone and CP+5 CAR group whereas decreased in CP+10 CAR group. CP+10 CAR group was significantly different in all parameters (except TAC) from CP+5 CAR group. Kidney microscopy was showed lower tissue damage in CP plus CAR groups. In conclusion, 10 mg/kg CAR is more effective than 5 mg/kg CAR in prevention of CP-induced oxidative damage on kidney.

Inhibition of NF-κB/TNF-α pathway may be involved in the protective effect of resveratrol against cyclophosphamide-induced multi-organ toxicity

CONTEXT

Cyclophosphamide (CyP), an efficient anticancer drug, may damage normal human cells. Resveratrol (RES), a natural polyphenol, has a diverse pharmacological properties.

OBJECTIVE

To test possible protective effect of RES on multi-organ damage caused by CyP.

MATERIALS AND METHODS

RES (10 mg/kg/day) was administered orally for 8 days. In independent rat groups, CyP toxicity was induced via a single dose of 150 mg/kg i.p. 3 days before the end of experiment, with or without RES treatment.

RESULTS

Compared to control, CyP caused significant increase in organ-to-body weight ratios of heart, kidney and liver, with deterioration in their functional parameters; namely serum creatine kinase, blood urea nitrogen, creatinine, alanine aminotransferase and aspartate aminotransferase. CyP also caused distortion in these organs' histology, with significant tissue oxidative stress, manifested by decrease in reduced glutathione and catalase, as well as increase in malondialdehyde and nitric oxide levels. Furthermore, CyP caused multi-organ inflammatory effects as shown by increased tumor necrosis factor-α levels, as well as up-regulation of nuclear factor-κB expressions. Using RES concurrently with CyP restored heart, kidney and liver functional parameters, as well as their normal histology. RES also reversed oxidative stress, as well as inflammatory signs caused by CyP alone.

CONCLUSIONS

RES may be beneficial adjuvant that confers multi-organ protection against CyP toxicity via antioxidant and anti-inflammatory mechanisms.

The mechanisms of cyclophosphamide-induced testicular toxicity and the protective agents

INTRODUCTION

Cyclophosphamide (CP) is an alkylating antineoplastic agent with known toxicity to the male reproductive system. Areas covered: This review summarizes the known mechanisms by which CP exerts its toxic effects on the male reproductive system and the methods utilized to prevent such effects so that it could be further investigated and applied in clinical use. Keywords including ['Cyclophosphamide' AND 'male reproductive' OR' sperm toxicity' OR 'spermatotoxicity' OR 'infertility] were searched through Google Scholar, PubMed and Scopus databases based on PRISMA guidelines. After removing duplicates and irrelevant data, 76 papers were reviewed concerning the outcomes of treatment of male mice, rats, and humans with CP and the effects of co-administration of various natural and synthetic compounds on male reproductive system. Expert opinion: CP exerts its effect mainly by inducing oxidative stress and changing gene expression in spermatocytes variably during different stages of development. These effects could be either restored or prevented by the administration of compounds with antioxidant properties and those which target the biochemical alterations induced by CP.

P-selectin-mediated LOX expression promotes insulinoma growth in Rip1-Tag2 mice by increasing tissue stiffness

P-selectin, a cell adhesion molecule, is an important member of the selectin family. Recent studies have shown that P-selectin deletion inhibits tumor growth in Rip1-Tag2 mice by suppressing platelet accumulation in tumor tissues. This study aimed to evaluate whether and how P-selectin affects tumor stiffness in Rip1-Tag2 mice. To explore the role of P-selectin in tissue stiffness, we demonstrated that tumor progression in Rip1-Tag2 mice was correlated with tissue stiffness using immunofluorescence and histological staining. Furthermore, we showed that P-selectin deficiency significantly decreased tissue stiffness by inhibiting lysyl oxidase (LOX) expression. Our experiments involving Rip1-Tag2 mice treated with the LOX inhibitor BAPN showed that BAPN significantly abolished collagen deposition to decrease tumor stiffness and thus inhibit tumor growth. These results indicate that P-selectin deletion significantly decreases tumor stiffness in Rip1-Tag2 mice by inhibiting LOX expression. Further study demonstrated that P-selectin-mediated platelet accumulation increases tissue stiffness mainly by increasing LOX expression and thus promotes tumor growth. Therefore, P-selectin may be an effective therapeutic targeting for treating human insulinomas.