Protective effects of arjunolic acid against cardiac toxicity induced by oral sodium nitrite: Effects on cytokine balance and apoptosis

Co-exposure of microcystin-LR and nitrite induced kidney injury through TLR4/NLRP3/GSDMD-mediated pyroptosis

The degradation of cyanobacterial blooms releases hazardous contaminants such as microcystin-LR (MC-LR) and nitrite, which may collectively exert toxicity on various bodily systems. To evaluate their individual and combined toxicity in the kidney, mice were subjected to different concentrations of MC-LR and/or nitrite over a 6-month period in this study. The results revealed that combined exposure to MC-LR and nitrite exacerbated renal pathological alterations and dysfunction compared to exposure to either compound alone. Specifically, the protein and mRNA expression of kidney injury biomarkers, such as kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL), were notably increased in combined exposure group. Concurrently, co-exposure to MC-LR and nitrite remarkedly upregulated levels of proinflammatory cytokines TNF-α, IL-6 and IL-1β, while decreasing the anti-inflammatory cytokine IL-10. Notably, MC-LR and nitrite exhibited synergistic effects on the upregulation of renal IL-1β levels. Moreover, MC-LR combined with nitrite not only elevated mRNA levels of proinflammatory cytokines but also increased protein levels of pyroptosis biomarkers such as IL-1β, Gasdermin D (GSDMD), and Cleaved-GSDMD. Mechanistic investigations revealed that co-exposure to MC-LR and nitrite promoted pyroptosis both in vivo and in vitro, possibly through the activation of the TLR4/NLRP3/GSDMD pathway. Pretreatment with TLR4 inhibitor and NLRP3 inhibitor effectively suppressed pyroptosis induced by the co-exposure of these two toxins in HEK293T cells. These findings provide compelling evidence that MC-LR combined with nitrite synergistically induces pyroptosis in the kidney by activating the TLR4/NLRP3/GSDMD pathway. Overall, this study significantly enhances our comprehension of how environmental toxins interact and induce harm to the kidneys, offering promising avenues for identifying therapeutic targets to alleviate their toxic effects on renal health.

Arjunolic acid reverses fluoxetine-induced alterations in testicular steroidogenic enzymes and membrane bound ionic pump imbalance through suppression of oxido-inflammatory stress and apoptosis

OBJECTIVE

The impact of the anti-depressant therapy on gonadal function has been recognized and discussed over the years. However, data to supplement our understanding of the impact of arjunolic acid (AA) therapies in protecting against FXT-induced gonadal dysfunction is lacking clear scientific evidence. Hence, this study aimed to investigate the possible effect of AA on fluoxetine-induced altered testicular function in rats.

METHODS

After 14 days acclimatization, Thirty-six (36) adult male rats were randomly divided into 6 groups (n=6). Rats in groups 1 received normal saline (10mL/kg); groups 2 & 3 were given AA (1.0mg/kg body weight) and AA (2.0mg/kg body weight), respectively; whereas, rats in group 4 were given FXT (10mg/kg/p.o/day), and groups 5 & 6 were given a combination of FXT (10mg/kg) + AA (1.0mg/kg body weight); and FXT (10mg/kg) + AA (2.0mg/kg body weight), respectively.

RESULTS

The results shows that FXT significantly altered testicular steroidogenic enzymes (3ß-HSD and 17ß-HSD) and proton pump ATPase (Na+/K+ ATPase, Ca2+ ATPase and H+ ATPase) activities, as well as testicular architecture when compared with controls. More so, FXT caused oxido-inflammation and apoptosis, as evidence by increases in MDA, MPO, TNF-α, IL-1ß, Caspase 3 and p53. However, AA at a different dose significantly ameliorated the destructive impacts of FXT on steroidogenic enzymes, proton pump ATPase as well as increased Bcl-2, SOD, CAT, GSH and improved testicular architecture in rats.

CONCLUSIONS

AA reverses fluoxetine-induced alterations in testicular steroidogenic enzymes and membrane-bound ionic pump through suppression of oxido-inflammatory stress and apoptosis.

Cardioprotective effects of arjunolic acid in LPS-stimulated H9C2 and C2C12 myotubes via the My88-dependent TLR4 signaling pathway

CONTEXT

Arjunolic acid (AA) is a triterpenoid saponin found in Terminalia arjuna (Roxb.) Wight & Arn. (Combretaceae). It exerts cardiovascular protective effects as a phytomedicine. However, it is unclear how AA exerts the effects at the molecular level.

OBJECTIVE

This study investigates the cardioprotective effects of arjunolic acid (AA) via MyD88-dependant TLR4 downstream signaling marker expression.

MATERIALS AND METHODS

The MTT viability assay was used to assess the cytotoxicity of AA. LPS induced in vitro cardiovascular disease model was developed in H9C2 and C2C12 myotubes. The treatment groups were designed such as control (untreated), LPS control, positive control (LPS + pyrrolidine dithiocarbamate (PDTC)-25 µM), and treatment groups were co-treated with LPS and three concentrations of AA (50, 75, and 100 µM) for 24 h. The changes in the expression of TLR4 downstream signaling markers were evaluated through High Content Screening (HCS) and Western Blot (WB) analysis.

RESULTS

After 24 h of co-treatment, the expression of TLR4, MyD88, MAPK, JNK, and NF-κB markers were upregulated significantly (2-6 times) in the LPS-treated groups compared to the untreated control in both HCS and WB experiments. Evidently, the HCS analysis revealed that MyD88, NF-κB, p38, and JNK were significantly downregulated in the H9C2 myotube in the AA treated groups. In HCS, the expression of NF-κB was downregulated in C2C12. Additionally, TLR4 expression was downregulated in both H9C2 and C2C12 myotubes in the WB experiment.

DISCUSSION AND CONCLUSIONS

TLR4 marker expression in H9C2 and C2C12 myotubes was subsequently decreased by AA treatment, suggesting possible cardioprotective effects of AA.

Promising Therapeutic Treatments for Cardiac Fibrosis: Herbal Plants and Their Extracts

Cardiac fibrosis is closely associated with multiple heart diseases, which are a prominent health issue in the global world. Neurohormones and cytokines play indispensable roles in cardiac fibrosis. Many signaling pathways participate in cardiac fibrosis as well. Cardiac fibrosis is due to impaired degradation of collagen and impaired fibroblast activation, and collagen accumulation results in increasing heart stiffness and inharmonious activity, leading to structure alterations and finally cardiac function decline. Herbal plants have been applied in traditional medicines for thousands of years. Because of their naturality, they have attracted much attention for use in resisting cardiac fibrosis in recent years. This review sheds light on several extracts from herbal plants, which are promising therapeutics for reversing cardiac fibrosis.

Therapeutic potential and industrial applications of Terminalia arjuna bark

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia arjuna (Roxb. ex DC.) Wight & Arnot (Combretaceae) is one of the most frequently used medicinal trees in Indian traditional medicinal systems. It is used for the treatment of a variety of diseases including cardiovascular disorders.

AIM OF THE STUDY

The purpose of this review was to provide a comprehensive overview of the phytochemistry, medicinal uses, toxicity, and industrial applications of T. arjuna bark (BTA), as well as to identify gaps in research and applications of this important tree. It also aimed to analyze trends and future research paths to utilize the full potential of this tree.

MATERIALS AND METHODS

Extensive bibliographic research on the T. arjuna tree was carried out using scientific research engines and databases such as Google Scholar, PubMed, and Web of Science, covering all relevant English-language articles. The database "World Flora Online (WFO)" (http://www.worldfloraonline.org) was used to confirm plant taxonomy.

RESULTS

To date, BTA has been traditionally employed for several disorders such as snakebites, scorpion stings, gleets, earaches, dysentery, sexual disorders, and urinary tract infections along with the cardioprotective activity. About 38 phytocompounds were identified from BTA and were classified as triterpenoids, tannins, flavonoids, and glycosides. A wide range of in vitro and in vivo pharmacological effects of BTA were reported such as anti-cancer, antimicrobial, antiviral, anti-inflammatory, antioxidant, hepatoprotective, anti-allergic, anti-diabetic, and wound healing activities. The oral administration of BTA (500 mg/kg) per day did not result in any toxicity in humans. The in vivo acute and sub-acute toxicity analysis of the methanol extract of BTA and one of its major compounds, 7-methyl gallate, did not produce any adverse effects up to a dose of 1000 mg/kg.

CONCLUSIONS

This comprehensive review highlights various aspects of traditional knowledge, phytochemicals, and pharmacological significance of BTA. The review covered safety information on employing BTA in pharmaceutical dosage forms. Despite its long history of medicinal benefit, more studies are needed to understand the molecular mechanisms, structure-activity relationship, and potential synergistic and antagonistic effects of its phytocompounds, drug administration, drug-drug interactions, and toxicological effects.

Design, synthesis, and biological evaluation of new arjunolic acid derivatives as anticancer agents

Arjunolic acid (AA) is a pentacyclic triterpenoid with promising anticancer properties. A series of novel AA derivatives containing a pentameric A-ring with an enal moiety, combined with additional modifications at C-28, were designed and prepared. The biological activity on the viability of human cancer and non-tumor cell lines was evaluated in order to identify the most promising derivatives. Additionally, a preliminary study of the structure-activity relationship was carried out. The most active derivative, derivative 26, also showed the best selectivity between malignant cells and non-malignant fibroblasts. For compound 26, the anticancer molecular mechanism of action in PANC-1 cells was further studied and the results showed that this derivative induced a cell-cycle arrest at G0/G1 phase and significantly inhibited the wound closure rate of PANC-1 cancer cells in a concentration-dependent manner. Additionally, compound 26 synergistically increased the cytotoxicity of Gemcitabine, especially at a concentration of 0.24 μM. Moreover, a preliminary pharmacological study indicated that at lower doses this compound did not demonstrate toxicity in vivo. Taken together, these findings suggest that compound 26 may be a valuable compound for the development of new pancreatic anticancer treatment, and further studies are needed to explore its full potential.

Berberine Recovered Oxidative Stress Induced by Sodium Nitrite in Rat Erythrocytes

OBJECTIVE

Berberine, a plant derived alkaloid, present in Berberis species is well known as one of the most important antioxidants. The current research aimed to study the heamatoprotective characteristics of berberine and clarify its plausible mechanisms against sodium nitrite.

METHODS

Forty numbers of male Sprague Dawley rats were categorized into five equal groups, including group 1: control (normal saline); group 2: berberine (100 mg/kg); group 3: sodium nitrite (80 mg/kg); group 4: sodium nitrite (80 mg/kg) plus berberine (50 mg/kg) and group 5: sodium nitrite (80 mg/kg) plus berberine (100 mg/kg) groups. All animals were orally administrated for two months once daily. At the end of the 60th day, blood samples were withdrawn by cardiac puncture and collected in test vials when the animals had been anesthetized with ketamine (70 mg/kg). Then, hemolysate was prepared and the oxidative stress biomarkers, lipid peroxidation, and antioxidant capacity of erythrocytes were evaluated.

RESULTS

Feeding of rats with sodium nitrite remarkably enhanced malondialdehyde (MDA) (p=0.001) levels and considerably reduced the levels of glutathione (GSH) (p=0.001), and also reduced the enzymatic activities of glutathione peroxidase (GPx) (p=0.02), superoxide dismutase (SOD) (p=0.001), glutathione reductase (GR) (p=0.02), and catalase (CAT) (p=0.01). However, the co-administration of these animals with 100 mg/kg of berberine remarkably reverted the values to reach nearly a normal level. While 50 mg/kg berberine failed to restore significantly all of these antioxidant biomarkers at a normal level.

CONCLUSION

Our results clearly demonstrated that berberine in a dose-dependent manner led to protection against sodium nitrite-induced oxidative injury in rat erythrocytes, which possibly reflects the antioxidant ability of this alkaloid.

In vivo evaluation of the protective effects of arjunolic acid against lipopolysaccharide-induced septic myocardial injury

Lipopolysaccharide (LPS) is a glycolipid component of the cell wall of Gram-negative bacteria, which induces multiple organ dysfunctions, eventually leading to septic shock and death. Arjunolic acid (AA) has been shown to have therapeutic benefits against various organ pathophysiologies, although its role in sepsis remains unclear. Here, we evaluated the effects of AA on LPS-induced free radical production and cardiotoxicity. Male albino mice were allocated to four groups: normal, 1.5 µg/30 g b.w. of LPS (LPS), 20 mg/kg b.w. AA with LPS (AA+LPS) and 20 mg/kg b.w. of AA (AA). Subsequently, blood and heart samples were harvested for biochemical and histopathological examinations. Pretreatment with AA attenuated LPS-induced increased serum levels of cardiac troponin I, lactate dehydrogenase and creatine kinase. In the meantime, AA pretreatment before LPS resulted in a significant increase in endogenous antioxidants (superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione) and a significant decrease in the level of lipid peroxidation product (malondialdehyde) in the heart as compared to the LPS group, while cardiac cytochrome c activity were significantly increased. In addition, in the AA-pretreated mice, C-reactive protein and proinflammatory cytokines (interlukin-1 and tumor necrosis factor-alpha) were significantly reduced, and anti-inflammatory cytokines (interleukin-4 and -10) were significantly increased in cardiac tissues as compared to the LPS-treated animals. Furthermore, prior administration of AA to LPS exposed mice led to a significant a significant decrease in heart caspase-3, -8, and -9 as compared to the LPS group. Interestingly, AA was also able to improve LPS-induced histopathological changes in the cardiomyocytes. In conclusion, these in vivo findings indicate that AA may be a promising cardioprotective agent against LPS-stimulated cardiotoxicity, at least in part, through upregulation of cardiac antioxidants, reduction of lipid peroxidation, and inhibition of inflammation and cardiac cell death.

Selective cytotoxic activity and protective effects of sodium ascorbate against hepatocellular carcinoma through its effect on oxidative stress and apoptosis in vivo and in vitro

Objectives: Hepatocellular carcinoma (HCC) is characterized by elevated in oxidative stress and inflammatory cytokines, which enhance destructive effects of the tumor. Therefore, we conducted this study to investigate the protective effects of sodium ascorbate against thioacetamide-induced HCC in rats through studying its effect on the apoptotic pathway in rats. In addition, in vitro activity of sodium ascorbate was investigated on HepG2 and compared with cisplatin.

Methods: HCC was experimentally induced by injecting rats with 200 mg/kg thioacetamide intraperitoneally twice weekly for 16 weeks. Part of HCC rats was concomitantly treated with 100 mg/kg sodium ascorbate intraperitoneally during the 16-week period. Hepatic tissues were used for the determination of NFκB, Nrf2, TNF-α, caspase-3, caspase-8 and caspase-9.

Results: Sodium ascorbate significantly attenuated HCC-induced reduction in the expression of NrF2 associated with a reduction in concentrations of hydrogen peroxide and superoxide anion. In addition, sodium ascorbate blocked HCC-induced increase in the expression of NFκB and TNF-α. Sodium ascorbate slightly increased the activity of caspase-3, -8 and -9 in vitro but inhibited their activities in vivo.

Conclusion: In spite of the antioxidant and anti-inflammatory activity of sodium ascorbate, it produced selective cytotoxic activity via direct activation of the apoptotic pathway in cancer cells without affecting the apoptotic pathway in normal hepatic cells.

Chlorella vulgaris ameliorates sodium nitrite-induced hepatotoxicity in rats

The current was conducted to evaluate the ameliorating effect of Chlorella vulgaris (CV) extract against sodium nitrite-induced hepatotoxicity in rats. Forty-five rats were allocated randomly into 5 groups (n = 9). Group I (GI), control group: orally gavaged with normal saline daily. Group II (GII): orally gavaged with CV extract (70 mg/kg BW) for 3 months. Group III (GIII): orally gavaged with sodium nitrite (80 mg/kg BW) for 3 months. Group IV (GIV): received sodium nitrite as GIII and CV extract as GII simultaneously for 3 months. Group V (GV): received CV extract as GII and then, sodium nitrite as in GIII from the end of first month until the end of the experiment. Sodium nitrite significantly increased the activities of serum alanine aminotransferase, aspartate aminotransferase, and serum concentrations of tumor interleukin 1-β and necrosis factor α. In addition, it increased concentrations of malondialdehyde and nitric oxide and expression level of caspase-3 in the hepatic tissue. However, it decreased activities of hepatic glutathione peroxidase, catalase, and superoxide dismutase and induced degenerative and necrotic changes in hepatic tissues. In contrast, CV extract administration modulated sodium nitrite-induced inflammation, oxidative stress, and alteration in hepatic tissue function and architecture. This study indicated that CV extract modulated sodium nitrite-induced hepatic toxicity through decreasing oxidative stress and inflammation and enhancing antioxidant enzyme activities in hepatic tissue of rats.

Hepatoprotective effect of arjunolic acid against cisplatin-induced hepatotoxicity: Targeting oxidative stress, inflammation, and apoptosis

Minimizing the adverse effects of chemotherapeutic agents remains a therapeutic challenge. Cisplatin (CP) induces hepatotoxicity through activation of oxidative stress, inflammation, and apoptosis cascades which is considered a significant drawback. Thus, this study aimed to highlight the possible hepatoprotective role of arjunolic acid (Arj) in a rat model of CP-induced hepatotoxicity. Four groups of rats were included; the normal control group, Arj control group, CP group which was injected with 7.5 mg/kg CP intraperitoneally to induce hepatotoxicity, and the treated group (Arj + CP), which was orally administered 20 mg/kg Arj for 10 days with a CP hepatotoxic dose on day 5. Blood and liver tissues were assembled for analysis at the end of the study. Pretreatment with Arj exhibited a marked improvement in liver function as well as histopathology when compared with the CP group. Moreover, Arj suppressed the oxidative stress in hepatic tissue by significantly decreasing malondialdehyde and nitric oxide contents along with markedly elevating the levels of superoxide dismutase, catalase, and reduced glutathione when compared with CP injected rats. Attenuation of hepatic inflammation and apoptosis was also reported with Arj treatment through the marked reduction in the proinflammatory cytokine tumor necrosis factor α level as well as the apoptotic marker caspase-3 protein expression in comparison to the CP group. This study explored for the first time the Arj hepatoprotective effect against CP-induced hepatotoxicity through its antioxidant, anti-inflammatory, and antiapoptotic activities.

In silico evaluation of apoptogenic potential and toxicological profile of triterpenoids

AIM:

Caspases-3 and 8 are key mediators of intrinsic and extrinsic pathway of apoptosis, respectively. Triterpenoids of natural and synthetic origin reported as anticancer agents with apoptotic potential and hence may prove to be good candidates for in silico testing against caspases-3 and 8.

MATERIALS AND METHODS:

Various naturally-occurring and synthetic triterpenoids were subjected to activity prediction using PASS Online software, and among them, 67 compounds were selected for further processing. Protein structure of caspase-3 (3DEI) and caspase-8 (3KJQ) was obtained from the protein data bank and docked with selected triterpenoids using AutoDock Tools and AutoDock Vina. Toxicological profile was predicted based on clinical manifestations using PASS online software.

RESULTS:

The high docking score of -10.0, -9.9, -9.8, and -9.5 were shown by friedelin, tingenone, albiziasaponin A, and albiziasaponin C, respectively, for caspase-3, and -11.0, -9.6, -9.6, and -9.4 by β-boswellic acid, bryonolic acid, canophyllic acid, and CDDO, respectively, for caspase-8. Possible adverse events were predicted with varying degree of probability and major relevant effects were reported. Hydrostatic interactions along with formation of hydrogen bonds with specific amino acids in the binding pocket were identified with each triterpenoid.

CONCLUSION:

Lead molecules identified through this in silico study such as friedelin, tingenone, albiziasaponin, bryonolic acid, and canophyllic acid may be utilized for further in vitro/in vivo studies as apoptotic agents targeting caspases-3 and 8.

Thymoquinone therapy remediates elevated brain tissue inflammatory mediators induced by chronic administration of food preservatives

Continuous exposure to preservatives such as nitrite salts has deleterious effects on different organs. Meanwhile, Nigella sativa oil can remediate such organ dysfunction. Here, we studied the effect of consumption of thymoquinone (TQ); the main component of Nigella sativa oil on the brain damage induced by sodium nitrite. Forty adult male rats were daily given oral gavage of sodium nitrite (80 mg/kg) with or without thymoquinone (50 mg/kg). Oxidative stress, cytokines of inflammation, fibrotic elements and apoptotic markers in brain tissue were measured. Exposure to sodium nitrite (SN) resulted in increased levels of malondialdehyde, TGF-β, c-reactive protein, NF-κB, TNF-α, IL-1β and caspase-3 associated with reduced levels of glutathione, cytochrome c oxidase, Nrf2 and IL-10. However, exposure of rats' brain tissues to thymoquinone resulted ameliorated all these effects. In conclusion, thymoquinone remediates sodium nitrite-induced brain impairment through several mechanisms including attenuation of oxidative stress, retrieving the reduced concentration of glutathione, blocks elevated levels of pro-inflammatory cytokines, restores cytochrome c oxidase activity, and reducing the apoptosis markers in the brain tissues of rats.

Protective effect of triterpenes against diabetes-induced β-cell damage: An overview of in vitro and in vivo studies

Accumulative evidence shows that chronic hyperglycaemia is a major factor implicated in the development of pancreatic β-cell dysfunction in diabetic patients. Furthermore, most of these patients display impaired insulin signalling that is responsible for accelerated pancreatic β-cell damage. Indeed, prominent pathways involved in glucose metabolism such as phosphatidylinositol 3-kinase/ protein kinase B (PI3-K/AKT) and 5' AMP-activated protein kinase (AMPK) are impaired in an insulin resistant state. The impairment of this pathway is associated with over production of reactive oxygen species and pro-inflammatory factors that supersede pancreatic β-cell damage. Although several antidiabetic drugs can improve β-cell function by modulating key regulators such as PI3-K/AKT and AMPK, evidence of their β-cell regenerative and protective effect is scanty. As a result, there has been continued exploration of novel antidiabetic therapeutics with abundant antioxidant and antiinflammatory properties that are essential in protecting against β-cell damage. Such therapies include triterpenes, which have displayed robust effects to improve glycaemic tolerance, insulin secretion, and pancreatic β-cell function. This review summarises most relevant effects of various triterpenes on improving pancreatic β-cell function in both in vitro and in vivo experimental models. A special focus falls on studies reporting on the ameliorative properties of these compounds against insulin resistance, oxidative stress and inflammation, the well-known factors involved in hyperglycaemia associated tissue damage.

Downregulation of flt-1 and HIF-1α Gene Expression by Some Antioxidants in Rats Under Sodium Nitrite-Induced Hypoxic Stress

This study assessed the effect of L-arginine (L-argin), carnosine (carno), or their combination in the amelioration of certain biochemical indices induced in the liver of hypoxic rats. Hypoxia was induced via sodium nitrite (S.nit) injection at a dose of 75 mg/kg. Rats were administered L-argin (250 mg/kg) or carno (250 mg/kg), either alone or in combination, 24 hours and 1 hour prior to S.nit intoxication. Hypoxia significantly elevated serum alanine aminotransferase, in addition to a significant upregulation of hepatic heat shock protein 70 with concurrent reduction in the level of vascular endothelial growth factor. Moreover, hepatic vascular endothelial growth factor 1 (flt-1), hypoxia inducible factor-1α gene expression, and cytochrome P450 levels were elevated, compared with the normoxic group. The antioxidants, administered either alone or in combination, markedly downregulated all of the previously mentioned biomarkers, compared to the hypoxic rats. Histopathological examination revealed hepatocellular degeneration and nuclear pyknosis, in addition to inflammatory cellular infiltration in the hypoxic rats, whereas treatment with the studied antioxidants improved the liver architecture. The present data revealed the efficacy of L-argin and carno in ameliorating the hepatic damage induced via angiogenic markers in response to hypoxia, the combination regimen showing the superior effect.

Roles of some antioxidants in modulation of cardiac myopathy induced by sodium nitrite via down-regulation of mRNA expression of NF-κB, Bax, and flt-1 and suppressing DNA damage

The underlying pathology of cardiac damage involves various molecular and signaling pathways. Therefore, this study aimed to explore the role of Quercetin (Querc), alone or in combination with Melatonin (Melat) against cardiac damage induced by sodium nitrite (Sod nit), as well as to elucidate different signaling pathways. Querc and Melat were injected intraperitoneally (i.p.), followed by induction of hypoxia in rats by using a single dose of Sod nit (60 mg/kg, s.c.). Treatment with Sod nit significantly decreased hemoglobin (Hb) levels in blood. Pretreatment of hypoxic rats with Querc and/or Melat elevated the declined Hb concentration. The forementioned antioxidants also successfully ameliorated the alteration of heat shock protein 70 (HSP-70) and markers of cardiac injury, including troponin T (Trop. T), creatine kinase-MB (CK-MB), tumor necrosis factor-α (TNF α), and C-reactive protein (CRP) in the rats serum. Furthermore, RT-PCR revealed that these antioxidants successfully modulated mRNA expression of NF-κB, Bax, Bcl-2, and flt-1. They also regulated vascular endothelial growth factor (VEGF), the apoptosis marker caspase 3, and oxidative DNA damage in cardiac tissue, compared to Sod nit-intoxicated rats. The present biochemical results are reinforced by histopathological examination.

IN CONCLUSION

The results reflected that treatment with Querc in combination with Melat was most effective in improving Sod nit-toxicity induced cardiac damage, thus confirming the promising role of this combination as an effective treatment for cardiac damage induced by other cardio-toxic agents.

Renal protective effects of thymoquinone against sodium nitrite-induced chronic toxicity in rats: Impact on inflammation and apoptosis

AIMS

Sodium nitrite is a widely used color fixative and preservative. However, it has been reported to exert deleterious toxic effects on various body organs. Moreover, thymoquinone (TQ), the active constituent of Nigella sativa oil is known to possess beneficial antioxidant and anti-inflammatory effects. The present study was conducted to evaluate the potential protective effects of TQ against sodium nitrite-induced renal toxicity.

MAIN METHODS

Male Sprague-Dawley rats were treated with sodium nitrite (80mg/kg, po, daily) in presence or absence of TQ (25 and 50mg/kg, po, daily). Morphological changes in renal sections were assessed by staining with Hematoxylin/Eosin and Periodic acid-Schiff. Renal homogenate was used for measurement of oxidative stress markers (MDA and GSH), inflammatory markers (CRP, TNF-α, IL-6, IL-1β), anti-inflammatory cytokines (IL-10 and IL-4) and apoptotic markers (caspase-3/caspase-8/caspase-9).

KEY FINDINGS

Treatment with sodium nitrite significantly increased markers of renal dysfunction, oxidative stress, inflammation and apoptosis. These effects were markedly attenuated by TQ in dose dependent manner.

SIGNIFICANCE

TQ has a potential protective effect against sodium nitrite-induced renal toxicity. This can be attributed to its ability to dampen oxidative stress, restore the normal balance between pro- and anti-inflammatory cytokines and protect renal tissue form extrinsic and intrinsic apoptosis.

Dietary intake alters gene expression in colon tissue: possible underlying mechanism for the influence of diet on disease

Supplemental Digital Content is available in the text.

Background

Although the association between diet and disease is well documented, the biologic mechanisms involved have not been entirely elucidated. In this study, we evaluate how dietary intake influences gene expression to better understand the underlying mechanisms through which diet operates.

Methods

We used data from 144 individuals who had comprehensive dietary intake and gene expression data from RNAseq using normal colonic mucosa. Using the DESeq2 statistical package, we identified genes that showed statistically significant differences in expression between individuals in high-intake and low-intake categories for several dietary variables of interest adjusting for age and sex. We examined total calories, total fats, vegetable protein, animal protein, carbohydrates, trans-fatty acids, mutagen index, red meat, processed meat, whole grains, vegetables, fruits, fiber, folate, dairy products, calcium, and prudent and western dietary patterns.

Results

Using a false discovery rate of less than 0.1, meat-related foods were statistically associated with 68 dysregulated genes, calcium with three dysregulated genes, folate with four dysregulated genes, and nonmeat-related foods with 65 dysregulated genes. With a more stringent false discovery rate of less than 0.05, there were nine meat-related dysregulated genes and 23 nonmeat-related genes. Ingenuity pathway analysis identified three major networks among genes identified as dysregulated with respect to meat-related dietary variables and three networks among genes identified as dysregulated with respect to nonmeat-related variables. The top networks (Ingenuity Pathway Analysis network score >30) associated with meat-related genes were (i) cancer, organismal injury, and abnormalities, tumor morphology, and (ii) cellular function and maintenance, cellular movement, cell death, and survival. Among genes related to nonmeat consumption variables, the top networks were (i) hematological system development and function, nervous system development and function, tissue morphology and (ii) connective tissue disorders, organismal injury, and abnormalities.

Conclusion

Several dietary factors were associated with gene expression in our data. These findings provide insight into the possible mechanisms by which diet may influence disease processes.

Medicinal properties of Terminalia arjuna (Roxb.) Wight & Arn.: A review

Medicinal plants have been a main source of therapeutic agents from ancient time to cure diseases. Terminalia arjuna (Roxb.) Wight & Arn. (T. arjuna) is one of the most accepted and beneficial medicinal plants in indigenous system of medicine for the treatment of various critical diseases. This comprehensive review provides various aspects of its ethnomedical, phytochemical, pharmacognostical, pharmacological and clinical significance to different diseases particularly in cardiovascular conditions. This plant has a good safety outline when used in combination with other conventional drugs. This review highlights various medicinal properties of T. arjuna through different studies such as antioxidant, hypotensive, anti-atherogenic, anti-inflammatory, anti-carcinogenic, anti-mutagenic and gastro-productive effect.

Sodium nitrite enhances generation of reactive oxygen species that decrease antioxidant power and inhibit plasma membrane redox system of human erythrocytes

Nitrite/nitrate salts are used in fertilizers and as food preservatives. Human exposure to high levels of nitrite results in its uptake and subsequent entry into blood where it can interact with erythrocytes. We show that treatment of human erythrocytes with sodium nitrite (NaNO2 ) results in a dose-dependent increase in the production of reactive oxygen species. This was accompanied by a decrease in the antioxidant power which lowered the free radical quenching and metal-reducing ability. NaNO2 treatment also inhibited plasma membrane redox system (PMRS) of erythrocytes. These changes increase the susceptibility of erythrocytes to oxidative damage, decrease the antioxidant power of whole blood, and can be a major cause of nitrite-induced cellular toxicity.

Thymoquinone ameliorated elevated inflammatory cytokines in testicular tissue and sex hormones imbalance induced by oral chronic toxicity with sodium nitrite

Scientific evidence illustrated the health hazards of exposure to nitrites for prolonged time. Nitrites affected several body organs due to oxidative, inflammatory and apoptosis properties. Furthermore, thymoquinone (TQ) had curative effects against many diseases. We tried to discover the impact of both sodium nitrite and TQ on inflammatory cytokines contents in testicular tissues and hormonal balance both in vivo and in vitro. Fifty adult male SD rats received 80mg/kg sodium nitrite and treated with either 25 or 50mg/kg TQ daily by oral-gavage for twelve weeks. Testis were removed for sperms' count. Testicular tissue homogenates were used for assessment of protein and gene expression of IL-1β, IL-6, TNF-α, Nrf2 and caspase-3. Serum samples were used for measurement of testosterone, LH, FSH and prolactin. Moreover, all the parameters were measured in human normal testis cell-lines, CRL-7002. Sodium nitrite produced significant decrease in serum testosterone associated with raised FSH, LH and prolactin. Moreover, sodium nitrite significantly elevated TNF-α, IL-1β, IL-6, caspase-3 and reduced Nrf2. TQ significantly reversed all these effects both in vivo and in vitro. In conclusion, TQ ameliorated testicular tissue inflammation and restored the normal balance of sex hormones induced by sodium nitrite both in vivo and in vitro.

Nigella sativa oil attenuates chronic nephrotoxicity induced by oral sodium nitrite: Effects on tissue fibrosis and apoptosis

OBJECTIVES

Sodium nitrite, a food preservative, has been reported to increase oxidative stress indicators such as lipid peroxidation, which can affect different organs including the kidney. Here, we investigated the toxic effects of oral sodium nitrite on kidney function in rats and evaluated potential protective effects of Nigella sativa oil (NSO).

METHODS

Seventy adult male Sprague-Dawley rats received 80 mg/kg sodium nitrite orally in the presence or absence of NSO (2.5, 5, and 10 ml/kg) for 12 weeks. Morphological changes were assessed by hematoxylin and eosin, Mallory trichome, and periodic acid-Schiff staining. Renal tissues were used for measurements of oxidative stress markers, C-reactive protein, cytochrome C oxidase, transforming growth factor (TGF)-beta1, monocyte chemotactic protein (MCP)-1, pJNK/JNK, and caspase-3.

RESULTS

NSO significantly reduced sodium nitrite-induced elevation in serum urea and creatinine, as well as increasing normal appearance of renal tissue. NSO also prevented reductions in glycogen levels caused by sodium nitrite alone. Moreover, NSO treatment resulted in dose-dependent significant reductions in fibrosis markers after sodium nitrite-induced 3- and 2.7-fold increase in MCP-1 and TGF-beta1, respectively. Finally, NSO partially reduced the elevated caspase-3 and pJNK/JNK.

DISCUSSION

NSO ameliorates sodium nitrite-induced nephrotoxicity through blocking oxidative stress, attenuation of fibrosis/inflammation, restoration of glycogen level, amelioration of cytochrome C oxidase, and inhibition of apoptosis.

Effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus)

Nitrite (NO2(-)) is commonly present as contaminant in aquatic environment and toxic to aquatic organisms. In the present study, we investigated the effects of nitrite exposure on haematological parameters, oxidative stress and apoptosis in juvenile turbot (Scophthalmus maximus). Fish were exposed to various concentrations of nitrite (0, 0.02, 0.08, 0.4 and 0.8mM) for 96 h. Fish blood and gills were collected to assay haematological parameters, oxidative stress and expression of genes after 0, 24, 48 and 96 h of exposure. In blood, the data showed that the levels of methemoglobin (MetHb), triglyceride (TG), potassium (K(+)), cortisol, heat shock protein 70 (HSP70) and glucose significantly increased in treatments with higher concentrations of nitrite (0.4 and/or 0.8mM) after 48 and 96 h, while the levels of haemoglobin (Hb) and sodium (Na(+)) significantly decreased in these treatments. In gills, nitrite (0.4 and/or 0.8mM) apparently reduced the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione (GSH), increased the formation of malondialdehyde (MDA), up-regulated the mRNA levels of c-jun amino-terminal kinase (JUK1), p53, caspase-3, caspase-7 and caspase-9 after 48 and 96 h of exposure. The results suggested caspase-dependent and JUK signaling pathways played important roles in nitrite-induced apoptosis in fish. Further, this study provides new insights into how nitrite affects the physiological responses and apoptosis in a marine fish.

Cod liver oil ameliorates sodium nitrite-induced insulin resistance and degradation of rat hepatic glycogen through inhibition of cAMP/PKA pathway

AIMS

Sodium nitrite is used to inhibit the growth of microorganisms and is responsible for the desirable red color of meat; however, it can be toxic in high quantities for humans and other animals. Moreover, glycogen, a branched polysaccharide, efficiently stores and releases glucose monosaccharides to be accessible for metabolic and synthetic requirements of the cell. Therefore, we examined the impact of dietary sodium nitrite and cod liver oil on liver glycogen.

MAIN METHODS

Thirty-two Sprague-Dawley rats were treated daily with sodium nitrite (80 mg/kg) in the presence/absence of cod liver oil (5 ml/kg). Liver sections were stained with Periodic acid-Schiff. Hepatic homogenates were used for measurements of glycogen, cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), glycogen synthase, glycogen synthase kinase, pyruvate carboxylase, fructose 1,6-diphosphatase, glucose 6-phosphatase, phosphodiesterase and glycogen phosphorylase. Glucose, pyruvate tolerances and HOMA insulin resistance were also determined.

KEY FINDINGS

Sodium nitrite significantly increased plasma glucose and insulin resistance. Moreover, sodium nitrite significantly reduced hepatic glycogen content as well as activities of glycogen synthase, glycogen synthase kinase-3, and phosphodiesterase. Sodium nitrite elevated hepatic cAMP, PKA, pyruvate carboxylase, fructose 1,6-diphosphatase, glucose 6-phosphatase and phosphorylase. Cod liver oil significantly blocked all of these except pyruvate carboxylase, fructose 1,6-diphosphatase and glucose 6-phosphatase.

SIGNIFICANCE

Sodium nitrite inhibited liver glycogenesis and enhanced liver glycogenolysis and gluconeogenesis, which is accompanied by hyperglycemia and insulin resistance through the activation of cAMP/PKA and the inhibition of phosphodiesterase. Cod liver oil blocked the sodium nitrite effects on glycogenesis and glycogenolysis without affecting gluconeogenesis.