Reno-protective effect of protocatechuic acid is independent of sex-related differences in murine model of UUO-induced kidney injury

BACKGROUND

Obstructive nephropathy is a condition often caused by urinary tract obstruction either anatomical (e.g., tumors), mechanical (e.g., urolithiasis), or compression (e.g., pregnancy) and can progress to chronic kidney disease (CKD). Studies have shown sexual dimorphism in CKD, where males were found to have a more rapid decline in kidney function following kidney injury compared to age-matched females. Protocatechuic acid (PCA), an anti-oxidant and anti-inflammatory polyphenolic compound, has demonstrated promising effects in mitigating drug-induced kidney injuries. The current study aims to explore sexual dimorphism in kidney injury after unilateral ureteral obstruction (UUO) and assess whether PCA treatment can mitigate kidney injury in both sexes.

METHODS

UUO was induced in 10-12 weeks old male and female C57BL/6J mice. Mice were categorized into four groups (n = 6-8/group); Sham, Sham plus PCA (100 mg/kg, I.P daily), UUO, and UUO plus PCA.

RESULTS

After 2 weeks of induction of UUO, markers of kidney oxidative stress (TBARs), inflammation (IL-1α and IL-6), tubular injury (neutrophil gelatinase-associated lipocalin, NGAL and urinary kidney injury molecule-1, KIM-1), fibrosis (Masson's trichrome staining, collagen IV expression, MMP-2 and MMP-9) and apoptosis (TUNEL+ cells, active caspase-1 and caspase-3) were significantly elevated in both males and females relative to their sham counterparts. Males exhibited significantly greater kidney oxidative stress, inflammation, fibrosis, and apoptosis after induction of UUO when compared to females. PCA treatment significantly attenuated UUO-induced kidney injury, inflammation, fibrosis, and apoptosis in both sexes.

CONCLUSION

Our findings suggest a differential gender response to UUO-induced kidney injury with males being more sensitive to UUO-induced kidney inflammation, fibrosis, and apoptosis than age-matched females. Importantly, PCA treatment reduced UUO-induced kidney injury in a sex-independent manner which might be attributed to its anti-oxidant, anti-inflammatory, anti-fibrotic, and anti-apoptotic properties.

Saroglitazar mitigated NASH-associated hepatic injury in dexamethasone-treated rats via modulating autophagy, apoptosis, and necroptosis

This study aimed to evaluate the possible ameliorative effects of saroglitazar (SAR) on aspects of hepatic injury in dexamethasone (DEX)-induced nonalcoholic steatohepatitis (NASH) in rats. Wistar rats received SAR (2 or 4 mg/kg/day, orally) or metformin (MET, 500 mg/kg/day, orally) for one week before and concurrently with DEX administration (8 mg/kg/day, i.p., for 6 days. Control and drug control groups received vehicle or the higher dose of SAR, respectively. At the end of the experiment, an oral glucose tolerance test (OGTT) was conducted, serum hepatic function parameters and lipid profile were assessed, and hepatic histological changes were evaluated. Moreover, hepatic p-Akt/Akt ratios, malondialdehyde (MDA) content, SREBP-1, FOXO1, LC3, cleaved caspase-3, and p-MLKL protein levels were determined. Furthermore, hepatic immunohistochemical expressions of FOXO1, caspase-3, Bcl-2, LC3, and P62 were examined. SAR (mainly at 4 mg/kg/day) significantly improved Area under the OGTT curve (P < 0.0001), hepatic function parameters, lipid profile, and hepatic histopathological features in DEX-administered rats. Moreover, SAR significantly attenuated DEX-induced increases in hepatic MDA content (P < 0.05), SREBP-1 levels (P < 0.0001), and nuclear FOXO1, caspase-3, LC3, P62, and p-MLKL protein expressions (P < 0.0001). Furthermore, SAR significantly enhanced hepatic p-Akt/Akt ratio and Bcl-2 protein expression in DEX-administered rats (P < 0.0001). The higher dose of SAR showed greater hepatoprotective effects compared to its corresponding lower dose and MET in most assessments, approaching levels similar to the control group. SAR mitigated hepatic injury associated with DEX-induced NASH in rats, suggesting it might be a potential hepatoprotective drug for patients with or at high risk of NASH.

Roflumilast extenuates inflammation and oxidative stress in cadmium-induced hepatic and testicular injury in rats

Roflumilast (ROF), a highly selective phosphodiesterase-4 inhibitor, has proven anti-inflammatory and immunomodulatory effects on the pulmonary system. However, the protective effects of ROF on cadmium (Cd)-induced hepatic and testicular injury has never been investigated. Adult male Sprague Dawley rats were acutely intoxicated with CdCl2 (3 mg/Kg, ip, qd, for 5 days). In treatment groups, ROF was administered in two doses (1.5 & 3 mg/Kg, po, qd, for 5 days) 2 h prior to CdCl2 intoxication. The results demonstrated that the therapeutic potential of ROF can extend beyond the pulmonary system. The histopathological manifestation of Cd in the liver and testes were evidently mitigated by ROF prophylaxis. This study unraveled the multi-faceted ROF protective mechanisms, these comprise (i) reviving normal liver and testicular architecture, (ii) lessen immune cell infiltration in injured tissues (iii) restoration of cellular oxidant status (GSH, SOD, NO and MDA), (iv) shielding pro-inflammatory signaling pathways (NF-κB, NLRP3, IL-1β axis), (v) dampening endoplasmic reticulum stress (IRE-1), (vi) mitigating apoptotic injury (caspase-3), (vii) restoring the integrity of blood testes barrier (Cathepsin-D) and (viii) promoting the regenerative potentials of injured testes (SDF-1). In conclusion, ROF is a promising anti-inflammatory and anti-oxidative candidate in Cd-induced hepatic and testicular injury.

Nilotinib alleviates paraquat-induced hepatic and pulmonary injury in rats via the Nrf2/Nf-kB axis

BACKGROUND

Paraquat (PQ, 1,1'-dimethyl-4-4'-bipyridinium dichloride) is a highly toxic quaternary ammonium herbicide widely used in agriculture. It exerts its toxic effects mainly as a result of its redox cycle via the production of superoxide anions in organisms, leading to an imbalance in the redox state of the cell causing oxidative damage and finally cell death. The aim of this study was to estimate the beneficial protective role of nilotinib (NIL) on PQ-induced hepatic and pulmonary toxicity in rats.

METHODS

Male wistar rats were randomly divided into four groups, namely control, PQ (15 mg/kg), PQ plus NIL (5 mg/kg) and PQ plus NIL (10 mg/kg). NIL (5 and 10 mg/kg/day) was taken by oral syringe for five days followed by a single intra-peritoneal administration of PQ (15 mg/kg) on sixth day.

RESULTS

Pretreatment with NIL relieved the histological damage in liver and lung tissues and improved hepatic biochemical markers. It significantly (p < 0.05) reduced serum levels of ALT, AST, ALP, Y-GT and total bilirubin while increased that of albumin. Meanwhile, NIL significantly (p < 0.05) reduced oxidative stress markers via reduction of malondialdhyde (MDA) and elevation of glutathione (GSH) contents in liver and lung tissues. In addition, it significantly (p < 0.05) decreased the inflammation by reducing hepatic and pulmonary tumor necrosis factor alpha (TNF-α) and nuclear transcription factor kappa B (NF-KB/p65) contents. Nilotinib also down-regulated apoptosis by reducing cysteinyl aspartate-specific proteinase-3 (caspase-3). Furthermore, it upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and microtubule-associated protein 1A/1B-light chain 3 II (LC3II) in liver and lung tissues.

SIGNIFICANCE

NIL suppressed PQ-induced inflammation, oxidative stress and apoptosis in liver and lung tissues by modulating Nrf2/Nf-kB axis.

Celecoxib abrogates concanavalin A-induced hepatitis in mice: Possible involvement of Nrf2/HO-1, JNK signaling pathways and COX-2 expression

Concanavalin A (ConA) is an established model for inducing autoimmune hepatitis (AIH) in mice, mimicking clinical features in human. The aimof the current study is to explore the possible protective effect of celecoxib, a cyclooxygenase-2 inhibitor,on immunological responses elicited in the ConA model of acute hepatitis. ConA (20 mg/kg) was administered intravenously to adult male mice for 6 h. Prior to ConA intoxication, mice in the treatedgroups received daily doses of celecoxib (30 and 60 mg/kg in CMC) for 7 days. Results revealed that administration of celecoxib 60 mg/kg for 7 days significantly protected the liver from ConA-induced liver damage revealed by significant decrease in ALT and AST serum levels. Celecoxib 30 and 60 mg/kg pretreatment enhanced oxidant/antioxidant hemostasis by significantreduction of MDA and NO content and increase hepatic GSH contents and SOD activity. In addition, celecoxib 30 and 60 mg/kg caused significant increase in hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) and the stress protein heme oxygenase-1 (HO-1) levels. Moreover, celecoxib 30 and 60 mg/kg inhibited the release of proinflammatory markers including IL-1β and TNF-α along with significant decrease in p-JNK, AKT phosphorylation ratio and caspase-3 expression. Besides, Con A was correlated to high expression of cyclooxygenase COX-2 and this increasing was improved by administration of celecoxib. These changes were in good agreement with improvement in histological deterioration. The protective effect of celecoxib was also associated with significant reduction of autophagy biomarkers (Beclin-1 and LC3II). In conclusion, celecoxib showed antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagy activity against Con A-induced immune-mediated hepatitis. These effects could be produced by modulation of Nrf2/HO-1, IL-1B /p-JNK/p-AKT, JNK/caspase-3, and Beclin-1/LC3II signaling pathways.

Saroglitazar, a dual PPAR-α/γ agonist, alleviates LPS-induced hepatic and renal injury in rats

BACKGROUND

Lipopolysaccharide (LPS), an endotoxin within gram-negative bacteria, is associated with systemic acute inflammatory response after invading living tissues and results in sepsis. The liver and kidney are both major target organs in sepsis. Septic acute hepatic-renal injury is a serious clinical condition with high risk of morbidity and mortality. Nevertheless, effective treatment is still lacking.

AIM

This study highlights saroglitazar (SAR), a dual PPAR-α/γ agonist, as a proposed prophylactic drug against LPS-induced hepatic-renal injury.

MAIN METHODS

Rats were pretreated with SAR (2 and 4 mg/kg/day) for 15 days, while sepsis was induced by LPS injection (10 mg/kg) on day 15 one hour following SAR oral administration.

KEY FINDINGS

SAR pretreatment could successfully mitigate LPS-induced hepatic-renal injury, evidenced by enhancement of renal and hepatic functions and a decrease of tissue pathological injury. Meanwhile, SAR alleviated LPS-induced oxidative stress; it reduced malondialdehyde (MDA) levels and ameliorated decreased levels of superoxide dismutase (SOD) and glutathione (GSH). LPS-induced elevations in hepatic and renal nuclear factor-kappa B (NF-κB), phosphorylated inhibitor of kappa B alpha (p-IκBα), interferon-beta (IFN-β), and hepatic high mobility group box-1 (HMGB-1) contents were significantly attenuated in SAR-treated groups. SAR showed an advantageous impact against LPS-induced activation of non-canonical inflammasome and pyroptosis via a significant reduction in cysteinyl aspartate-specific proteinase-11 (Caspase-11) and gasdermin D (GSDMD) expressions. Moreover, Nucleotide-Binding Oligomerization Domain (NOD)-Like Receptor Protein 3 (NLRP3) inflammasome activation with concomitant expression and activation of caspase-1 and release of interleukin-1beta (IL-1β) were considerably diminished following SAR pretreatment.

SIGNIFICANCE

SAR could be considered a prophylactic anti-inflammatory antioxidant drug against LPS-induced liver and kidney injury.

Flavocoxid halts both intestinal and extraintestinal alterations in acetic acid-induced colitis in rats

Ulcerative colitis (UC) is an idiopathic chronic inflammatory disorder mainly affecting the colon and rectum. The present investigation was undertaken to evaluate the potential protective effect of flavocoxid, a dual COX and LOX inhibitor, in colitis model in rats. UC was induced by instillation of 2 ml of 4% acetic acid (AA) into the colon using a pediatric catheter in rats, and flavocoxid (10 and 20 mg·kg^-1) was given once daily for 7 days before induction of colitis. Rats were sacrificed; sera were collected; colons and livers were isolated and then analyzed by biochemical, macroscopic, and histopathological examination. Pretreatment with flavocoxid (10 and 20 mg·kg^-1) significantly reduced serum levels of alanine transaminase (ALT) (43.7 ± 7 and 76.2 ± 7.3 vs. 288.7 ± 31.4 in AA group) and aspartate transaminase (AST) (179.5 ± 22.2 and 200.5 ± 14 vs. 392.7 ± 35.6 in AA group) (p>0.05). Also, it decreased malondialdehyde (MDA) and nitric oxide (NOx) levels in both colonic and hepatic tissues. Moreover, flavocoxid effectively elevated colonic and hepatic reduced glutathione (GSH) level and superoxide dismutase (SOD) activity when compared to AA group (p>0.05). Additionally, flavocoxid significantly decreased levels of tumor necrosis factor-α (TNF-α) (878.2 ± 13.4 and 560.1 ± 2.9 vs. 1378.1 ± 31 in AA group) in colonic tissues and (701 ± 6.9 and 442.5 ± 8.2 vs. 1501 ± 9.4 in AA group) in hepatic tissues, nuclear factor kappa B (NF-κBp65) (493.8 ± 6.8 and 368.7 ± 3.1 vs. 659.2 ± 9.4 in AA group) in colonic tissues and (358 ± 5.1 and 163.5 ± 7.8 vs. 732.5 ± 4.5 in AA group) in hepatic tissues, myeloperoxidase (MPO) (15.7 ± 0.3 and 13 ± 0.2 vs. 20.9 ± 0.5 in AA group) in colonic tissues and (20.4 ± 0.3 and 16.3 ± 0.3 vs. 23.9 ± 1.2 in AA group) in hepatic tissues, and inducible nitric oxide synthase (iNOS) (12.5 ± 0.3 and 10 ± 0.2 vs. 16 ± 0.1 in AA group) in colonic tissues and (14.1 ± 0.04 and 11.5 ± 0.08 vs. 17.8 ± 0.1 in AA group) in hepatic tissues (p>0.05). Furthermore, it down-regulated Bax and caspase-3 expression in colonic and hepatic tissues upon comparison with AA group. Collectively, flavocoxid conferred a protective impact against acetic acid-induced colitis in rats via attenuating oxidative stress, inflammation, and apoptosis.

The HIV reverse transcriptase Inhibitor Tenofovir suppressed DMH/HFD-induced colorectal cancer in Wistar rats

Colon rectal cancer (CRC) is the second commonest malignancy in developed countries and a significant cause of mortality. Tenofovir reportedly reduces the risk of hepatocellular carcinoma and interferes with cell cycle and cell proliferation. The current study investigated the potential antitumor effect of tenofovir against experimentally induced CRC. CRC was induced by 1,2-dimethylhydrazine (DMH, 20 mg/kg, once a week) and high-fat diet (HFD) in Wistar rats. Rats received tenofovir at a dose of 25 or 50 mg/kg (i.p.) for 24 weeks. Tenofovir-25 failed to significantly decrease the total number of dysplasia, adenoma and adenocarcinoma and to improve histopathological changes; however, tenofovir-50 resulted in no tumors seen in the colon lumen and a significant decrease in the total number of dysplasia and no adenoma or adenocarcinoma observed compared to DMH/HFD group. Tenofovir-25 failed to attenuate DMH/HFD-induced cell proliferation, whereas tenofovir-50 significantly decreased cell proliferation revealed by the decreased PCNA expression. Tenofovir-25 also failed to attenuate DMH/HFD-induced oxidative stress, whereas tenofovir-50 significantly attenuated oxidative stress as indicated by the decreased MDA concentration and SOD activity along with the increased GSH concentrations. Moreover, tenofovir-50 decreased Bcl-2 and cyclin D1 expressions in colon tissues compared with DMH/HFD group. Tenofovir-50 also significantly decreased INF-ɤ concentration in colon tissues. These findings suggest that the high dose of tenofovir (50 mg/kg) has antitumor potential against DMH/HFD-induced CRC, which might be mediated through the inhibition of cell proliferation, oxidative stress, and inflammation.

Molsidomine alleviates acetic acid-induced colitis in rats by reducing oxidative stress, inflammation and apoptosis

Ulcerative colitis (UC) is a subcategory of intestinal inflammatory bowel disease characterized by up-regulation of proinflammatory cytokines and oxidative stress. The current study was designed to assess the probable protective effect of the nitric oxide (NO) donor, molsidomine, in experimental colitis model in rats. Rats were haphazardly classified into four groups: control, acetic acid, acetic acid + molsidomine (1 mg/kg) and acetic acid + molsidomine (2 mg/kg). Molsidomine (1 and 2 mg/kg/day) was administered by intra-peritoneal injection for 7 days prior to induction of UC. On the 8th day, colitis was induced by intra-rectal instillation of 2 ml of (4% v/v) acetic acid in normal saline using a pediatric plastic catheter. The rats were sacrificed 1 day following colitis induction, blood samples were obtained; colons and livers were isolated then underwent macroscopic, biochemical, histopathological and immunohistochemical examination. Pretreatment with molsidomine significantly reduced disease activity index, colon mass index, colonic macroscopic and histological damage. Besides, molsidomine significantly reduced the serum levels of alanine transaminase (ALT) (58.7 ± 8.9 & 59.7 ± 8 vs 288.75 ± 31.4 in AA group) and aspartate transaminase (AST) (196.2 ± 37.4 & 204 ± 30 vs 392.7 ± 35.6 in AA group). Moreover, molsidomine effectively decreased malondialdehyde (MDA) and total nitrate/nitrite (NOx) contents, and up regulated the enzymatic activity of superoxide dismutase (SOD) and glutathione level (GSH) in colonic and hepatic tissues. With regard to anti-inflammatory mechanisms, molsidomine suppressed tumor necrosis factor-alpha (TNF-α) (792.5 ± 16.7 & 448 ± 12.1 vs 1352.5 ± 45.8 in AA group) in colonic tissues and (701 ± 19 & 442.5 ± 22.5 vs 1501 ± 26 in AA group) in hepatic tissues as well as nuclear transcription factor kappa B (NF-kB/p65) levels (416.2 ± 4.1 & 185.5 ± 14.2 vs 659.2 ± 11.5 in AA group) in colonic tissues and (358 ± 6.2 & 163.5 ± 9.6 vs 732.5 ± 5.5 in AA group) in hepatic tissues. In addition, molsidomine significantly decreased inducible nitric oxide synthase (iNOS) levels (8.1 ± 0.1 & 4.9 ± 0.1 vs 16 ± 0.1 in AA group) in colonic tissues and (8.6 ± 0.3 & 6.1 ± 0.1 vs 17.8 ± 0.1 in AA group) in hepatic tissues, and myeloperoxidase (MPO) contents (10.5 ± 0.4 & 6.6 ± 0.3 vs 20.9 ± 0.6 in AA group) in colonic tissues and (13.1 ± 0.2 & 6.3 ± 0.06 vs 23.9 ± 1.4 in AA group) in hepatic tissues at p > 0.05. Furthermore, it suppressed apoptosis by reducing expression of Caspase 3 and Bax in colonic and hepatic tissues. Therefore, molsidomine might be a promising candidate for the treatment of UC.

Impact of protocatechuic acid on high fat diet-induced metabolic syndrome sequelae in rats

The study aimed to assess the possible protective impact of protocatechuic acid (PCA) on high fat diet (HFD)-induced metabolic syndrome (Mets) sequelae in rats. Forty-two male Sprague-Dawley (SD) rats were randomly grouped as follows: CTR group; PCA group; HFD group; HFD-PCA group and HFD-MET group. Rats were fed on standard diet or HFD for 14 weeks. HFD-fed rats exhibited significant decreases in food intake and adiponectin (ADP) level; yet, body weight and anthropometrical parameters were significantly increased. Moreover, insulin sensitivity was impaired as indicated by significant elevation in glucose AUC during oral glucose tolerance test (OGTT), fasting serum glucose, fasting serum insulin and homeostasis model assessment of insulin resistance (HOMA-IR) index. Furthermore, chronic HFD feeding elicited significant increases in serum lipid profile and free fatty acids (FFAs) with concomitant hepatic steatosis. Additionally, serum C-reactive protein (CRP), interleukin 1b (Il-1b) and monocyte chemoattractant protein 1(MCP-1) levels were increased. Also, HFD-fed rats exhibited an increase in MDA level, while superoxide dismutase (SOD) and glutathione (GSH) activities were decreased. Moreover, the insulin-signaling pathway was markedly impaired in soleus muscles as indicated by a decrease in insulin-induced AKT phosphorylation. Histopathologically, adipose tissues showed significant increase in adipocyte size. Also, flow cytometry analysis of adipose tissue confirmed a significant increase in the percentage of number of CD68⁺ cells. PCA administration succeeded to attenuate HFD-induced obesity, insulin resistance, oxidative stress and inflammation. In conclusion, PCA administration could protect against HFD-induced Mets, possibly via its hypoglycemic, insulin-sensitizing, anti-oxidant and anti-inflammatory effects.

The protective effect of protocatechuic acid on hepatotoxicity induced by cisplatin in mice

Cisplatin is one of the most potent anti-cancer drugs used for the treatment of various solid tumors, yet it has several side effects that may limit its clinical use. Hepatotoxicity is one of the most serious side effects as it may lead to liver failure. Several mechanisms including oxidative stress, inflammation, and apoptosis have been examined in cisplatin-induced hepatotoxicity. Protocatechuic acid (Proto) which is naturally occurring phenolic acid has shown different biological activity as antioxidant, anti-inflammatory, and anti-apoptotic. In this study, we investigate the protective effect of Proto at two doses 100 and 150 mg/kg on hepatotoxicity induced by a single injection of 10 mg/kg cisplatin in female albino mice. The present study demonstrates for the first time that Proto administration (100 and 150 mg/Kg) significantly attenuates cisplatin-induced changes in liver function [increase serum albumin and decrease liver injury markers ALT, AST, GGT, and bilirubin]. This was associated with marked hepatic antioxidant effects [decrease MDA and NO levels, increase GSH and SOD activity]. Moreover, Proto reduced cisplatin-induced apoptosis in the liver through decreasing caspase-3, annexin-V, and BAX. Both doses suppressed cisplatin-induced expression of iNOS and NF-ᴋB p65 subunit and pro-inflammatory cytokines (IL-6 and TNF-α). Also, Proto improved histopathological examination of the liver. The present findings reveal that the antioxidant, anti-inflammatory, and anti-apoptotic effects of Proto are the main mechanisms by which Proto can ameliorate cisplatin-induced liver injury.

Protocatechuic acid improves hepatic insulin resistance and restores vascular oxidative status in type-2 diabetic rats

This work explored influences of protocatechuic acid (PCA) on type 2 diabetes (T2D)-associated hepatic insulin resistance and other metabolic, hepatic and vascular irregularities using the rat model of high fat diet (HFD)+high fructose+low dose streptozotocin (STZ). Twenty-four male Wister rats were used. Twelve rats were ad libitum supplied with HFD and high fructose drinking water (25 % w/v) for 60 days. On day 30, they received a single injection of STZ (35 mg/kg, i.p). On day 32, they were divided into two subgroups (n = 6/each): T2D + PCA, received PCA (100 mg/kg/day, orally) and T2D, received PCA vehicle till the end of experiment. Rats provided with regular diet and fructose-free drinking water, with or without PCA treatment, served as PCA and control groups (n = 6/each), respectively. PCA treatment significantly reduced the elevated levels of fasting glycemia and insulin, AUCOGTT, AUCITT, and HOMA-IR index, while it boosted HOMA-β and insulinogenic index values in T2D rats. PCA ameliorated serum lipid levels and hepatic function parameters and mitigated hepatosteatosis in T2D rats. Mechanistically, PCA mitigated hepatic lipid peroxidation and restored reduced glutathione (GSH) and superoxide dismutase (SOD) to near-normal levels. Moreover, PCA enhanced hepatic protein levels of P-AKTser473 and hepatic mRNA expression of insulin receptor substrate 1 (IRS1), phosphatidylinositol 3 kinase (PI3K)-p85 and AKT2. Furthermore, PCA ameliorated aortic oxidative stress in T2D rats, possibly via reducing serum levels of advanced glycation end products (AGEs) and diminishing vascular expression of RAGE and NOX4 mRNA. Collectively, PCA may improve hepatic insulin resistance and vascular oxidative status by modulating IRS1/PI3K/AKT2 and AGE-RAGE-NOX4 pathways, respectively.

Anti-apoptotic effect of vinpocetine on cisplatin-induced hepatotoxicity in mice: The role of Annexin-V, Caspase-3, and Bax

Hepatic damage is one of the most common complications related to cisplatin (Cis) use. Recently, liver protection lines are being discovered to avoid hepatic cell death as a result of oxidative, inflammatory, and apoptotic disturbance. Limited data reported the hepatoprotective effect of vinpocetine (Vin) in acute liver injury models. This study was designed to determine the potential protective effect of Vin (10-30 mg/kg, orally) against Cis-induced liver injury (10 mg/kg, IP) in mice. Vin administration for 1 week before Cis injection until the end of the experiment. On the 6th day after Cis injection, mice were anesthetized, blood and tissue samples were collected. Hepatic function, histological changes, oxidative stress, inflammation, and apoptotic markers were investigated. Vin administration ameliorated liver injury as indicated by decreased liver injury parameters; serum aminotransferases, ALK-P, GGT, and bilirubin, restored the anti-oxidant status by decrease MDA and NO_x , and increased GSH and SOD, inhibited inflammation (IL-6, TNF-α, NFκB-p65, and iNOS) and apoptosis (Annexin-V, Bax, and Caspase-3) parameters. Vin confers dose-dependent protection against Cis-induced liver injury. The hepatoprotective effect of Vin involved anti-oxidative, anti-inflammatory, and anti-apoptotic activities.

Protocatechuic acid exhibits hepatoprotective, vasculoprotective, antioxidant and insulin-like effects in dexamethasone-induced insulin-resistant rats

Protocatechuic acid (PCA), the natural phenolic antioxidant, reportedly exhibited hypoglycemic and insulin-like effects. Recent studies have reported its cardioprotective effect in glucocorticoid (GC)-induced hypertensive rats. Nevertheless, its beneficial role has not been investigated in the setting of GCs excess-induced insulin resistance. This study aimed to investigate the possible protective potential and the plausible mechanisms of pretreatment with PCA against GCs-induced insulin resistance, liver steatosis and vascular dysfunction. Insulin resistance was induced in male Wistar rats by a 7-day treatment with dexamethasone (DEX) (1 mg/kg/day, i.p.). PCA (50, 100 mg/kg/day, orally) was started 7 days before DEX administration and continued during the test period. PCA significantly and dose-dependently attenuated DEX-induced a) glucose intolerance (↓ AUC_OGTT), b) hyperglycemia (↓ fasting blood glucose), c) impaired insulin sensitivity [↓fasting plasma insulin and homeostasis model assessment of insulin resistance (HOMA-IR) index)] and d) dyslipidemia (↓total cholesterol, triglycerides, low-density lipoprotein-cholesterol and very low-density lipoprotein-cholesterol). PCA mitigated DEX-induced liver steatosis with associated reduction in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity. Moreover, PCA ameliorated DEX-induced vascular dysfunction and enhanced ACh-induced relaxation in aortic rings. The metabolic ameliorating effects of PCA might be attributed to the enhanced insulin signaling in soleus muscles (↑AKT phosphorylation) and mitigating gluconeogenesis (↓ hepatic mRNA expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase). The vasculoprotective effect of PCA might be related to its ability to restore normal mRNA expression of [endothelial nitric oxide synthase (eNOS) and NADPH Oxidase 4 (NOX4)]. PCA restored normal oxidative balance [↓ oxidant species, malondialdehyde (MDA) and (↑ antioxidant superoxide dismutase (SOD)]. The findings herein reveal for the first time that PCA may be taken as a supplement with GCs to limit their metabolic and vascular side effects through its hypoglycemic, insulin-sensitizing, hypolipidemic and antioxidant effects.

Comparison of the effects of sulforaphane and pioglitazone on insulin resistance and associated dyslipidemia, hepatosteatosis, and endothelial dysfunction in fructose-fed rats

The purpose of this work was to compare the influences of sulforaphane (SFN) to those of the standard insulin sensitizer pioglitazone (PIO) on high fructose diet (HFrD)-induced insulin resistance, dyslipidemia, hepatosteatosis, and vascular dysfunction in rats. Male Sprague Dawley rats (150-200 g) were fed on a standard diet (control) or a high fructose diet (HFrD, 60% w/w fructose) for 60 days. From day 16, two subgroups of HFrD-fed rats received either SFN (0.5 mg/kg/day, orally) or PIO (5 mg/kg/day, orally) along with HFrD until the end of the experiment. Fructose-fed rats showed significant decreases in food intake, body weight and feeding efficiency; effects that were not altered by either treatment. Data from insulin tolerance test (ITT), oral glucose tolerance test (OGTT), and HOMA-IR and HOMA-β indices demonstrated impaired insulin sensitivity and glucose utilization in HFrD-fed rats. SFN and PIO treatments significantly reduced OGTT_AUC (Glass's Delta values = 1.12 and 0.84, respectively), decreased ITT_AUC (Glass's Delta values = 1.05 and 0.71, respectively), significantly diminished HOMA-IR index (by 55.6% and 77.6%, respectively), and increased HOMA-β value (by 1.8 and 1.3 fold, respectively) compared to the HFrD rats. Moreover, SFN and PIO ameliorated hepatic oxidative stress and reduced serum levels of C-reactive protein and lactate dehydrogenase in HFrD-fed rats. Furthermore, SFN and PIO administrations improved insulin resistance-associated heaptosteatosis and enhanced vascular responsiveness to acetylcholine-induced relaxations. However, only SFN was able to enhance serum HDL-C levels in HFrD group. These finding suggests that SFN elicited insulin-sensitizing, hepatoprotective, and vasculoprotective effects in HFrD insulin-resistant rats that were comparable to those exerted by PIO.

Synthesis and in vitro antitumor evaluation of some new thiophenes and thieno[2,3-d]pyrimidine derivatives

New thiophene (2-13) and thienopyrimidine (15-27) derivatives have been synthesized. Twenty three compounds were screened against five cell lines namely; hepatocellular carcinoma (liver) HepG-2, epidermoid carcinoma (larynx) Hep-2, mammary gland (breast) MCF-7, human prostate cancer PC-3 and epithelioid cervix carcinoma HeLa. The results revealed that compounds 15,16,17,24 and 25 showed the highest antitumor activity against all tested cell lines compared to Doxorubicin. In order to explain the expected mode of action of the observed anticancer activity, compounds 15,16,17,24 and 25 were selected to screen their DNA binding affinity and enzyme inhibitory activity against DNA polymerase, thymidylate synthase and tyrosine kinase. The results revealed that the tested compounds showed good DNA binding affinity as well as good inhibitory activity against the three enzymes which might explain the observed anticancer activity of the target compounds.

Purification, characterization and immunogenicity assessment of glutaminase free L-asparaginase from Streptomyces brollosae NEAE-115

Background

L-asparaginase is a potential therapeutic enzyme widely used in the chemotherapy protocols of pediatric and adult patients with acute lymphoblastic leukemia. However, its use has been limited by a high rate of hypersensitivity in the long-term used. Hence, there is a continuing need to search for other L-asparaginase sources capable of producing an enzyme with less adverse effects.

Methods

Production of extracellular L-asparaginase by Streptomyces brollosae NEAE-115 was carried out using submerged fermentation. L-asparaginase was purified by ammonium sulphate precipitation and pure enzyme was reached using ion-exchange chromatography, followed by enzyme characterization. Anticancer activity towards Ehrlich Ascites Carcinoma (EAC) cells was investigated in female Swiss albino mice by determination of tumor size and the degree of tumor growth inhibition. The levels of anti-L-asparaginase IgG antibodies in mice sera were measured using ELISA method.

Results

The purified L-asparaginase showed a total activity of 795.152 with specific activity of 76.671 U/mg protein and 7.835 − purification fold. The enzyme purity was confirmed by using SDS–PAGE separation which revealed only one distinctive band with a molecular weight of 67 KDa. The enzyme showed maximum activity at pH 8.5, optimum temperature of 37 °C, incubation time of 50 min and optimum substrate concentration of 7 mM. A Michaelis-Menten constant analysis showed a K_m value of 2.139 × 10^− 3 M with L-asparagine as substrate and V_max of 152.6 UmL^− 1 min^− 1. The half-life time (T_1/2) was 65.02 min at 50°С, while being 62.65 min at 60°С. Furthermore, mice treated with Streptomyces brollosae NEAE-115 L-asparaginase showed higher cytotoxic effect (79% tumor growth inhibition) when compared to commercial L-asparaginase group (67% tumor growth inhibition).

Conclusions

The study reveals the excellent property of this enzyme which makes it highly valuable for development of chemotherapeutic drug.

Cinnamaldehyde exerts vasculoprotective effects in hypercholestrolemic rabbits

The effects of cinnamaldehyde (CIN), a commonly consumed food flavor, against high-cholesterol diet (HCD)-induced vascular damage in rabbits were evaluated. Male New Zealand rabbits (n = 24) were allocated to four groups at random: control, fed with standard rabbit chow; CIN, fed with standard diet and administered CIN; HCD, fed with 1% cholesterol-enriched diet; and HCD-CIN, fed with HCD and treated with CIN. CIN was orally given at a dose of (10 mg/kg/day) concomitantly with each diet type from day 1 until the termination of the experimental protocol (4 weeks). HCD elicited significant elevations in serum levels of total cholesterol (TC), triglycerides (TGs), and high- and low-density lipoprotein cholesterol (HDL-C and LDL-C, respectively) compared with control rabbits. Moreover, aortic levels of nitric oxide metabolites (NOx) and antioxidant enzyme activities were significantly lower, while aortic levels of malondialdehyde (MDA) and myeloperoxidase (MPO) activity were significantly higher, in HCD-fed rabbits relative to control animals. CIN administration mitigated or completely reversed HCD-induced metabolic alterations, vascular oxidative stress, and inflammation. Moreover, CIN ameliorated HCD-induced vascular functional and structural irregularities. Aortic rings from HCD-CIN group showed improved relaxation to acetylcholine compared to aortas from HCD group. Moreover, CIN decreased atherosclerotic lipid deposition and intima/media (I/M) ratio of HCD aortas. CIN-mediated effects might be related to its ability to attenuate the elevated aortic mRNA expression of cholesteryl ester transfer protein (CETP) and MPO in HCD group. Interestingly, the vasculoprotective effects of CIN treatment in the current study do not seem to be mediated via Nrf2-dependent mechanisms. In conclusion, CIN may mitigate the development of atherosclerosis in hypercholestrolemic rabbits via cholesterol-lowering, antiinflammatory and antioxidant activities.

Flavocoxid attenuates airway inflammation in ovalbumin-induced mouse asthma model

Asthma is a common airways inflammatory disease. This study provides evidence on the efficacy of flavocoxid against ovalbumin (OVA)-induced allergic airways inflammation in a mouse model of asthma. Airway inflammation was induced by intrapеritonеal injection of 10 mg ovalbumin (OVA) on day zero and day 7 followed by OVA challenge starting from 14th day to 16th day. Beclomethasone; a standard anti-inflammatory agent was selected as a drug in asthma. Flavocoxid (20 mg/kg, i. p.) was administered on day zero till 16th day followed by OVA challenge. At the end of the study, lung weight index, bronchoalveolar lavage fluid (BALF) content of total and differential WBCs, interleukin-13(IL-13), in addition to lung tissue nitrate/nitrite (NO) and oxidative stress biomarkers were measured. Also, histological and immunohistochemical analysis were conducted. Daily i. p. injection of flavocoxid (20 mg/kg) significantly improved airway inflammation. Inflammatory cells in BALF, malondialdehyde (MDA), NO and IL-13 significantly declined with concomitant increase in superoxide dismutase (SOD) activity. Histopathological examination and immunohistochеmical staining of mast cells were correlated with observed biochemical improvements. Collectively, these results demonstrate that flavocoxid mitigates the allergic airway inflammation induced by ovalbumin through attenuation of IL-13, NO expressions and oxidative stress.

Allicin ameliorates kidney function and urinary bladder sensitivity in cyclosporine A-treated rats

Cyclosporine-A (CsA) is an immunosuppressive drug which has been used to prevent rejection after organ transplantation and to treat certain autoimmune diseases. However, its therapeutic use is limited by nephrotoxicity. In this study, the modulator effect of allicin on the oxidative nephrotoxicity of CsA in rats was investigated. Furthermore, the effect of allicin on CsA-induced hypersensitivity of urinary bladder rings to acetylcholine (ACh) was estimated. Rats were divided into three groups, control, CsA (15 mg/kg, subcutaneously), and CsA/allicin (50 mg/kg, orally). At the end of the study, all rats were killed and then blood, urine samples, and kidneys were taken. CsA administration caused a severe nephrotoxicity which was evidenced by elevated kidney/body weight ratio, serum creatinine (Cr), blood urea nitrogen, lactate dehydrogenase, and urinary protein with a concomitant reduction in serum albumin and Cr clearance as compared with control. A significant increase in renal contents of malondialdehyde, myeloperoxidase, and tumor necrosis factor-alpha with a significant decrease in renal reduced glutathione, superoxide dismutase activities, and nitric oxide (NOx) content was detected upon CsA administration. Exposure to CsA increased the sensitivity of isolated urinary bladder rings to ACh. Histological analysis revealed that CsA caused tubular necrosis and moderate diffuse tubular atrophy. Allicin protected kidney tissue against the oxidative damage and the nephrotoxic effect of CsA and significantly reduced the responses of isolated bladder rings to ACh. Our study indicates that allicin administration has the potential to protect against CsA-induced renal injury by reducing oxidative stress and inflammation and restoring NOx level.

Agmatine improves renal function in gentamicin-induced nephrotoxicity in rats

The present study was designed to explore the possible protective effects of agmatine, a known nitric oxide (NO) synthase inhibitor, against gentamicin-induced nephrotoxicity in rats. For this purpose, we quantitatively evaluated gentamicin-induced renal structural and functional alterations using histopathological and biochemical approaches. Furthermore, the effect of agmatine on gentamicin-induced hypersensitivity of urinary bladder rings to acetylcholine (ACh) was evaluated. Twenty-four male Wistar albino rats were randomly divided into 3 groups, namely control, gentamicin (100 mg/kg, i.p.), and gentamicin plus agmatine (40 mg/kg, orally). At the end of the study, all rats were sacrificed and then blood and urine samples and kidneys were taken. Administration of agmatine significantly decreased kidney/body mass ratio, serum creatinine, lactate dehydrogenase (LDH), renal malondialdehyde (MDA), myeloperoxidase (MPO), NO, and tumor necrosis factor-alpha (TNF-α) while it significantly increased creatinine clearance and renal superoxide dismutase (SOD) activity when compared with the gentamicin-treated group. Additionally, agmatine ameliorated tissue morphology as evidenced by histological evaluation and reduced the responses of isolated bladder rings to ACh. Our study indicates that agmatine administration with gentamicin attenuates oxidative-stress associated renal injury by reducing oxygen free radicals and lipid peroxidation, restoring NO level and inhibiting inflammatory mediators such as TNF-α.

Sulforaphane attenuates the development of atherosclerosis and improves endothelial dysfunction in hypercholesterolemic rabbits

The aim of the present work was to explore possible protective effects of sulforaphane (SFN) against atherosclerosis development and endothelial dysfunction in hypercholesterolemic rabbits. Rabbits were assigned to three groups of five: group I fed normal chow diet for four weeks, group II fed 1% high cholesterol diet (HCD) and group III fed HCD + SFN (0.25 mg/kg/day). Blood samples were collected for measurement of serum triglycerides (TGs), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), lactate dehydrogenase (LDH) and C-reactive protein (CRP). Aortic malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and total nitrite/nitrate (NOx) were measured. Vascular reactivity and intima/media (I/M) ratio were analyzed. Nuclear factor-kappa B (NF-κB) activation in aortic endothelial cells was identified immunohistochemically. HCD induced significant increases in serum TGs, TC, LDL-C, LDH, and CRP, and aortic MDA and SOD. Moreover, HCD caused significant reductions in serum HDL-C, aortic GSH and NOx. SFN administration significantly decreased HCD-induced elevations in serum TC, LDL-C, CRP, and LDH. while significantly increased HDL-C and GSH levels and normalized aortic SOD and NOx. Additionally, SFN significantly improved rabbit aortic endothelium-dependent relaxation to acetylcholine. Moreover, SFN significantly reduced the elevation in I/M ratio. This effect was confirmed by aortic histopathologic examination. The expression of NF-κB in aortic tissue showed a marked reduction upon treatment with SFN. In conclusion, this study reveals that SFN has the ability to ameliorate HCD-induced atherosclerotic lesions progression and vascular dysfunction, possibly via its lipid-lowering and antioxidant effects and suppression of NF-κB-mediated inflammation.

Protective effect of allicin against gentamicin-induced nephrotoxicity in rats

In this study, the modulator effect of allicin on the oxidative nephrotoxicity of gentamicin in the kidneys of rats was investigated by determining indices of lipid peroxidation and the activities of antioxidant enzymes, as well as by histological analyses. Furthermore, the effect of allicin on gentamicin induced hypersensitivity of urinary bladder rings to ACh was estimated. Twenty-four male Wistar albino rats were randomly divided into three groups, control, gentamicin (100mg/kg, i.p.) and gentamicin+allicin (50mg/kg, orally). At the end of the study, all rats were sacrificed and then urine, blood samples and kidneys were taken. Gentamicin administration caused a severe nephrotoxicity as evidenced by an elevated kidney/body weight ratio, serum creatinine, blood urea nitrogen (BUN), serum lactate dehydrogenase (LDH) and proteinuria with a reduction in serum albumin and creatinine clearance as compared with control group. In addition, a significant increase in renal contents of malondialdehyde (MDA), myeloperoxidase (MPO), nitric oxide (NOx) and tumor necrosis factor-alpha (TNF-α) concomitantly with a significant decrease in renal reduced glutathione (GSH) and superoxide dismutase (SOD) activities was detected upon gentamicin injection. Exposure to gentamicin increased the sensitivity of isolated urinary bladder rings to ACh and induced acute renal tubular epithelial cells necrosis. Administration of allicin significantly decreased kidney/body weight ratio, serum creatinine, LDH, renal MDA, MPO, NOx and TNF-α while it significantly increased creatinine clearance, renal GSH content and renal SOD activity when compared to gentamicin-treated group. Additionally, allicin significantly reduced the responses of isolated bladder rings to ACh and ameliorated tissue morphology as evidenced by histological evaluation. Our study indicates that allicin exerted protection against structural and functional damage induced by gentamicin possibly due to its antioxidant, anti-inflammatory and immunomodulatory properties in addition to its ability to retaining nitric oxide level.

Attenuation of oxidative stress, inflammation, and endothelial dysfunction in hypercholesterolemic rabbits by allicin

Allicin, the active substance of garlic, exerts a broad spectrum of pharmacological activities and is considered to have potential therapeutic applications. The present study was designed to investigate the possible beneficial effects of allicin against oxidative stress, inflammation, and endothelial dysfunction in hypercholesterolemic rabbits. Male New Zealand white rabbits were used in this study. Rabbits randomly received 1 of the following treatments: normal chow diet for 4 weeks, 1% high cholesterol diet (HCD), HCD plus allicin (10 mg/kg/day), or HCD plus atorvastatin (10 mg/kg/day). Blood samples were collected at the end of experimental diets for measurement of serum total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C), C-reactive protein (CRP), malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD). In addition, the aorta was removed for measurement of vascular reactivity, histopathological changes, intima/media (I/M) ratio, and immunohistochemical staining of both tumor necrosis-alpha (TNF-α) and nuclear factor (NF)-κB. HCD induced significant increases in serum TC, TGs, low-density lipoprotein cholesterol (LDL-C), CRP, and MDA. Moreover, HCD caused significant decrease in serum GSH and SOD. In addition, aortic relaxation response to acetylcholine (ACh) was impaired. Immunohistochemical staining of aortic specimens from HCD-fed rabbits revealed high expression levels of both TNF-α and the oxidant-induced transcription factor, NF-κB. Allicin supplementation significantly decreased serum MDA and CRP, increased serum HDL-C, GSH, and SOD levels while nonsignificantly affecting HCD-induced elevations in serum TC and LDL-C. Additionally, allicin significantly protected against HCD-induced attenuation of rabbit aortic endothelium-dependent relaxation to ACh and elevation in I/M ratio. This effect was confirmed by histopathological examination of the aorta. Moreover, allicin has substantially beneficial effects on aortic expression of TNF-α and NF-κB compared with HCD-fed rabbits. In conclusion, these findings demonstrate that allicin may be useful in reducing oxidative stress, inflammation, vascular dysfunction, and the aortic pathology in hypercholesterolemic rabbits.

LPS-RS attenuation of lipopolysaccharide-induced acute lung injury involves NF-κB inhibition

In this study, we studied the effect of lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS), an inhibitor of Toll-like receptor 4 (TLR4), in LPS-induced acute lung injury (ALI). Male Sprague-Dawley rats were treated with LPS-RS (0.1 mg/kg body mass, by intraperitoneal (i.p.) injection) 1 h before LPS injection (10 mg/kg, i.p.). Bronchoalveolar lavage fluid (BALF) and lung tissues were collected 24 h later to determine total and differential cell count, total protein content, levels of lactate dehydrogenase (LDH), histopathological changes, markers of oxidative stress, and mRNA expression of the inhibitory protein nuclear factor kappaB-α (NFκBIA) and TLR4. Additionally, rings of pulmonary artery were isolated for measuring vascular reactivity. LPS-induced ALI was indicated by increases in total and differential cell count, total protein, and LDH in BALF, and increased lung levels of malondialdehyde (MDA), as well as decreased activity of reduced glutathione (GSH) and superoxide dismutase (SOD). Moreover, LPS increased pulmonary artery contraction in response to phenylephrine (PE). Additionally, LPS downregulated mRNA expression of NFκBIA and upregulated mRNA expression of TLR4. LPS caused a marked inflammation in the lung tissue, with tubercular granuloma and numerous neutrophils. Pretreatment with LPS-RS protected against LPS-induced ALI by decreasing total and differential cell count, total protein, and LDH in BALF, and increased pulmonary GSH content and SOD activity without affecting MDA content. Additionally, it decreased the elevated PE-induced pulmonary artery contraction. LPS-RS upregulated mRNA expression of NFκBIA and downregulated mRNA expression of TLR4. Moreover, LPS-RS prevented inflammation in lung tissues. In conclusion, pretreatment with LPS-RS protects against LPS-induced ALI in rats through its anti-inflammatory effects, possibly by decreasing the mRNA expression of TLR4 and increasing that of NFκBIA.

Montelukast attenuates lipopolysaccharide-induced cardiac injury in rats

This study investigates the possible protective effects of montelukast (MNT) against lipopolysaccharide (LPS)-induced cardiac injury, in comparison to dexamethasone (DEX), a standard anti-inflammatory. Male Sprague Dawley rats (160–180 g) were assigned to five groups ( n = 8/group): (1) control; (2) LPS (10 mg/kg, intraperitoneal (i.p.)); (3) LPS + MNT (10 mg/kg, per os (p.o.)); (4) LPS + MNT (20 mg/kg, p.o.); and (5) LPS + DEX (1 mg/kg, i.p.). Twenty-four hours after LPS injection, heart/body weight (BW) ratio and percent survival of rats were determined. Serum total protein, creatine kinase muscle/brain (CK-MB), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) activities were measured. Heart samples were taken for histological assessment and for determination of malondialdehyde (MDA) and glutathione (GSH) contents. Cardiac tumor necrosis factor α (TNF-α) expression was evaluated immunohistochemically. LPS significantly increased heart/BW ratio, serum CK-MB, ALP, and LDH activities and decreased percent survival and serum total protein levels. MDA content increased in heart tissues with a concomitant reduction in GSH content. Immunohistochemical staining of heart specimens from LPS-treated rats revealed high expression of TNF-α. MNT significantly reduced percent mortality and suppressed the release of inflammatory and oxidative stress markers when compared with LPS group. Additionally, MNT effectively preserved tissue morphology as evidenced by histological evaluation. MNT (20 mg/kg) was more effective in alleviating LPS-induced heart injury when compared with both MNT (10 mg/kg) and DEX (1 mg/kg), as evidenced by decrease in positive staining by TNF-α immunohistochemically, decrease MDA, and increase GSH content in heart tissue. This study demonstrates that MNT might have cardioprotective effects against the inflammatory process during endotoxemia. This effect can be attributed to its antioxidant and/or anti-inflammatory properties.

Montelukast reduces sepsis-induced lung and renal injury in rats

This study was undertaken to examine the effects of montelukast (MNT) on lung and kidney injury in lipopolysaccharide (LPS) induced systemic inflammatory response. Rats were randomized into 5 groups (n = 8 rats/group): (i) Control; (ii) LPS treated (10 mg/kg body mass, by intraperitoneal (i.p.) injection); (iii) LPS + MNT (10 mg/kg, per oral (p.o.)); (iv) LPS + MNT (20 mg/kg, p.o); (v) LPS + dexamethasone (DEX; 1 mg/kg, i.p.). Twenty-four hours after sepsis was induced, the lung or kidney:body mass ratio and percent survival of rats were determined. Creatinine, blood urea nitrogen (BUN), albumin, total protein, and LDH activity were measured. Lung and kidney samples were taken for histological assessment and for determination of their malondialdehyde (MDA) and glutathione (GSH) contents. The expression of tumour necrosis factor α (TNF-α) in tissue was evaluated immunohistochemically. LPS significantly increased the organ:body mass ratio, serum creatinine, BUN, and LDH, and decreased serum albumin and total protein levels. MDA levels increased in lung and kidney tissues after treatment with LPS, and there was a concomitant reduction in GSH levels. Immunohistochemical staining of lung and kidney specimens from LPS-treated rats revealed high expression levels of TNF-α. MNT suppresses the release of inflammatory and oxidative stress markers. Additionally, MNT effectively preserved tissue morphology as evidenced by histological evaluation. These results demonstrate that MNT could have lung and renoprotective effects against the inflammatory process during endotoxemia. This effect can be attributed to its antioxidant and (or) anti-inflammatory properties.

Protective role of thymoquinone against liver damage induced by tamoxifen in female rats

One of the major reasons for terminating a clinical trial is the liver toxicity induced by chemotherapy. Tamoxifen (TAM) is an anti-estrogen used in the treatment and prevention of hormone-dependent breast cancer. Tamoxifen therapy may cause hepatic injury. The seeds of Nigella sativa, which contain the active ingredient thymoquinone (TQ), have been used in folk medicine for diverse ailments. TQ is reported to possess anticancer and hepatoprotective effects. In this study, the protective effects of TQ against TAM-induced hepatotoxicity in female rats were evaluated. Four groups of rats were used: control; TAM; TQ; TAM+TQ. TAM (45 mg·(kg body mass)–1·day–1, by intraperitoneal injection (i.p.), for 10 consecutive days) resulted in elevated serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, total bilirubin, and gamma glutamyl transferase, as well as depletion of reduced glutathione in the liver and accumulation of lipid peroxides. Also, TAM treatment inhibited the hepatic activity of superoxide dismutase. Further, it raised the levels of tumor necrosis factor alpha in the liver and induced histopathological changes. Pretreatment with TQ (50 mg·(kg body mass)–1·day–1; orally, for 20 consecutive days, starting 10 days before TAM injection) significantly prevented the elevation in serum activity of the assessed enzymes. TQ significantly inhibited TAM-induced hepatic GSH depletion and LPO accumulation. Consistently, TQ normalized the activity of SOD, inhibited the rise in TNF-α and ameliorated the histopathological changes. In conclusion, TQ protects against TAM-induced hepatotoxicity.

Allicin enhances chemotherapeutic response and ameliorates tamoxifen-induced liver injury in experimental animals

CONTEXT

Tamoxifen (TAM) is widely used for treatment of hormone-dependent breast cancer; however, it may be accompanied with hepatic injury. Allicin is the most abundant thiosulfinate molecule from garlic with the potential to provide beneficial effects on various diseases.

OBJECTIVE

To elucidate the effect of commercially available allicin on both antitumor activity and liver injury of TAM.

MATERIALS AND METHODS

The cytotoxicity of TAM and/or allicin was evaluated in vitro using cultured Ehrlich ascites carcinoma (EAC) cells and in vivo against murine tumor (solid) model of EAC. TAM induced liver injury in rats by intraperitoneally (i.p.) injection at a dose of 45 mg/kg, for 7 successive days.

RESULTS

TAM at a dose of 3 µM (IC50) significantly decreased percent survival of EAC to 52%. TAM combination with allicin (5 or 10 µM) showed a significant cytotoxic effect compared with the TAM-treated group as manifested by a decrease in percent survival of EAC to 35% and 29%, respectively. Allicin (10 mg/kg, orally) enhanced the efficacy of TAM (1 mg/kg, i.p.) in mice as manifested by a significant increase in solid tumor growth inhibition by 82% compared with 70% in the TAM group. In rats, TAM intoxication resulted in a significant decline in SOD, GSH, and total protein with significant elevation in TBARS, ALT and AST, ALP, LDH, total bilirubin, γGT, and TNF-α levels. These changes are abrogated by allicin treatment.

DISCUSSION AND CONCLUSION

The results suggest the beneficial role of allicin as an adjuvant to TAM in cancer treatment by alleviating liver injury.

Agmatine ameliorates atherosclerosis progression and endothelial dysfunction in high cholesterol-fed rabbits

OBJECTIVES

The aim of this work was to explore possible effects of agmatine, an endogenous inhibitor of inducible nitric oxide synthase (iNOS), against hypercholesterolemia-induced lipid profile changes and endothelial dysfunction.

METHODS

Hypercholesterolemia was induced by feeding rabbits with a high-cholesterol diet (HCD, 0.5%) for 8 weeks. Another HCD-fed group was orally administered agmatine (10 mg/kg/day) during weeks 5 through 8. Serum lipid profile, malondialdehyde (MDA), nitric oxide (NO) and lactate dehydrogenase (LDH) were determined. Aorta was isolated to analyse vascular reactivity, atherosclerotic lesions and intima/media (I/M) ratio.

KEY FINDINGS

HCD induced a significant increase in serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides and high-density lipoprotein cholesterol (HDL-C). Agmatine administration significantly decreased HCD-induced elevations in serum TC and LDL-C, MDA, LDH and NO while significantly increased HDL-C levels. Additionally, agmatine significantly protected against HCD-induced attenuation of rabbit aortic endothelium-dependent relaxation to acetylcholine. HCD and agmatine did not significantly influence aortic endothelium-independent relaxation to sodium nitroprusside. Moreover, agmatine significantly reduced the elevation in aortic atherosclerotic lesion area and I/M ratio.

CONCLUSIONS

This study is the first to reveal that agmatine has the ability to ameliorate hypercholesterolemia-induced lipemic-oxidative and endothelial function injuries possibly by its antioxidant potential and/or iNOS inhibition.

Effect of age on the contractile response of the rat carotid artery in the presence of sympathetic drugs and L-NAME

For evaluating the age-related change in noradrenaline (NA)-induced contraction of isolated rat carotid artery (CA), the effect of α and β adrenoreceptor (AR) blockers and the role of nitric oxide (NO) were investigated.

METHODS

Concentration-response curves to NA (10-10-10-4 M) and α1 agonist phenylephrine (PE; 10-10-10-5 M) were constructed in isolated CA rings from young and middle-aged rats. The effects of nitric oxide synthase (NOS) inhibitor (L-NAME; 100 μM), α1-AR antagonist (prazosin; 0.1 μM), α2-AR antagonist (yohimbine; 0.1 μM) and β-AR antagonist (propranolol; 1 μM) on NA-induced contraction of isolated CA rings were examined. In CA rings preconstricted with NA, the responses to α2-AR agonist (clonidine; 10-7-10-5 M), β-AR agonist (isoprenaline; 10-8-10-5 M),), sodium nitroprusside (SNP; 10-9-10-5 M) were assessed.

RESULTS

The maximum contractile response of CA to NA and to PE was higher in younger than in middle-aged rats. Prazosin reduced the contractile response to NA in both groups, while propranolol, yohimbine and L-NAME did not affect NA-induced contraction in either of them. Clonidine, isoprenaline and SNP produced a dose-dependent vasorelaxation of CA rings, isoprenaline-induced vasodilatation was lower in middle-aged rats, while there was no difference in clonidine or SNP-induced relaxant effect between the two groups.

CONCLUSIONS

NA-induced contraction of isolated rat CA rings is decreased in old rats, this is related to α1-AR. β-AR mediated dilatation was compromised in middle-aged rats (endothelium-dependent). α2-AR and SNP-mediated dilator effect seems to be unchanged.

Propolis protects against high glucose-induced vascular endothelial dysfunction in isolated rat aorta

While propolis is known to have abundant bioactive constituents and a variety of biological activities, it is not clear whether propolis has beneficial effects on high glucose-mediated vascular endothelial impairment. The aim of the present study was to investigate the potential protective effect of propolis extract against the acute vascular endothelial dysfunction resulting from exposure to high glucose load and to elucidate its underlying mechanism. Rat aortic rings were incubated with normal glucose (11 mM), high glucose (44 mM), or mannitol (44 mM) for 3 h with or without propolis extract (400 μg/ml). Contraction to phenylephrine (Phe, 10(-9)-10(-5) M) and relaxation to acetylcholine (ACh, 10(-9)-10(-5) M) and sodium nitroprusside (SNP, 10(-9)-10(-5) M) were measured before and after incubation. Changes in malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) were also measured. Phe-induced contraction was impaired by high glucose as the E(max) decreased from 138.87 ± 11.43 to 103.65 ± 11.5 %. In addition, ACh-induced relaxation was impaired as the E(max) decreased from 99.80 ± 7.25 to 39.20 ± 6.5 %. SNP-induced relaxation was not affected. Furthermore, high glucose decreased the levels of both SOD (by 6 U/ml) and GSH (by 68 %) and increased levels of MDA (by 85 %). Propolis extract prevented high glucose-induced impairment of Phe and ACh responses and increased both SOD and GSH, leading to decreased MDA levels. In conclusion, propolis can protect against high glucose-induced vascular dysfunction by reducing oxidative stress.

Modulation of cyclophosphamide-induced early lung injury by allicin

CONTEXT

Cyclophosphamide (CP) causes lung injury in rats through its ability to generate free radicals with subsequent epithelial and endothelial cell damage.

OBJECTIVE

This study was conducted to assess whether allicin can ameliorate CP-induced early lung injury in rats.

MATERIALS AND METHODS

Male Sprague Dawely rats were divided into four groups. Group I was the control group. Group II received allicin (50 mg/kg/d, p.o.) for 14 consecutive days. Group III was injected once with CP (150 mg/kg, i.p.). Group IV received allicin for seven consecutive days, before and after CP injection (150 mg/kg, i.p.). The parameters of study were serum biomarkers, lung tissue antioxidant profile and histopathological changes in lung tissue.

RESULTS

A single intraperitoneal injection of CP markedly altered the levels of several biomarkers in lung homogenates. Significant increases in lung content of lipid hydroperoxides were seen that paralleled the decreased levels of total reduced glutathione. Superoxide dismutase activity (SOD) was significantly increased. CP increased the level of serum biomarkers; total protein, lactate dehydrogenase (LDH) and tumor necrosis factor-alpha (TNF-α). Pretreatment of rats daily with oral allicin seven days prior to and seven days after CP inject significantly inhibited the development of lung injury, prevented the alterations in lung and serum biomarkers associated with inflammatory reactions, with less lipid peroxidation (LP) and restoration of antioxidants. Moreover, allicin attenuated the secretion of proinflammatory cytokine, TNF-α expression in rat serum. In addition, allicin effectively blunted CP-induced histopathological changes in lung tissue.

DISCUSSION AND CONCLUSION

Our results suggest that allicin is efficient in blunting CP-induced pulmonary damage.

Cardioprotective effect of grape-seed proanthocyanidins on doxorubicin-induced cardiac toxicity in rats

CONTEXT

Doxorubicin (Dox) is an anthracycline antibiotic used as anticancer agent. However, its use is limited due to its cardiotoxicity which is mainly attributed to accumulation of reactive oxygen species.

OBJECTIVE

This study was conducted to assess whether the antioxidant, proanthocyanidins (Pro) can ameliorate Dox-induced cardiotoxicity in rats.

MATERIALS AND METHODS

Male Sprague-Dawely rats were divided into four groups. Group I was control. Group II received Pro (70 mg/kg, orally) once daily for 10 days. Group III received doxorubicin 15 mg/kg i.p. as a single dose on the 7th day and Group IV animals were treated with Pro once daily for 10 days and Dox on the 7th day. The parameters of study were serum biomarkers, cardiac tissue antioxidant status, ECG, and effect on aconitine-induced cardiotoxicity.

RESULTS

Cardiac toxicity of doxorubicin was manifested as a significant increase in heart rate, elevation of the ST segment, prolongation of the QT interval and an increase in T wave amplitude. In addition, Dox enhanced aconitine-induced cardiotoxicity by a significant decrease in the aconitine dose producing ventricular tachycardia (VT). Administration of Pro significantly suppressed Dox-induced ECG changes and normalized the aconitine dose producing VT. The toxicity of Dox was also confirmed biochemically by significant elevation of serum CK-MB and LDH activities as well as myocardial MDA and GSH contents and decrease in serum catalase and myocardial SOD activities. Administration of Pro significantly suppressed these biochemical changes.

DISCUSSION AND CONCLUSION

These results suggest that proanthocyanidins might be a potential cardioprotective agent against Dox-induced cardiotoxicity due to its antioxidant properties.

Montelukast ameliorates kidney function and urinary bladder sensitivity in experimentally induced renal dysfunction in rats

Effect of montelukast on the renal dysfunction induced by cisplatin was investigated. A single dose of cisplatin (7 mg/kg, i.p.) induced nephrotoxicity, which was manifested by increasing the sensitivity of isolated urinary bladder rings to acetylcholine (ACh) together with a significant elevation of serum creatinine, blood urea nitrogen, and lactate dehydrogenase. On the other hand, serum albumin was significantly decreased. Moreover, renal dysfunction was further confirmed by a significant increase in lipid peroxides that were measured as malondialdehyde (MDA) in kidney tissue homogenate. Kidney reduced glutathione (GSH) content and superoxide dismutase (SOD) activity were measured, which were decreased and increased, respectively. Administration of montelukast (10 mg/kg/day, p.o.) 5 days before and 5 days after cisplatin injection significantly ameliorated the renotoxic effects of cisplatin, as judged by a significant reduction in the responses of isolated bladder rings to ACh. The deleterious changes induced by cisplatin treatment in kidney function parameters and oxidative stress markers were significantly mitigated by montelukast treatment.

CONCLUSION

Montelukast may be a beneficial remedy for cisplatin-induced renal dysfunction.

Celecoxib, a selective cyclooxygenase-2 inhibitor, attenuates renal injury in a rat model of Cisplatin-induced nephrotoxicity

BACKGROUND

Cisplatin is an effective chemotherapeutic agent successfully used in the treatment of a wide range of tumors. Nevertheless, nephrotoxicity has restricted its clinical use. Recent studies have strongly suggested that inflammatory mechanisms may play an important role in the pathogenesis of cisplatin nephrotoxicity. Celecoxib, a selective cyclooxygenase-2 inhibitor used as anti-inflammatory, may therefore have a protective effect on cisplatin-induced renal injury.

METHODS

In the present study, rats were injected intraperitoneally with a single dose of cisplatin (7 mg/kg) and/or celecoxib (30 mg/kg) for 5 days.

RESULTS

Nephrotoxicity manifested biochemically by elevations in serum creatinine, blood urea nitrogen, and proteinuria, and an increase in kidney weight as a percentage of total body weight. In addition, a marked decrease in serum albumin was observed. Lipid peroxidation in the kidney was monitored by measuring the malondialdehyde level and glutathione content, which were increased and depleted, respectively. Administration of celecoxib with cisplatin attenuated cisplatin-induced changes in kidney function parameters and oxidative stress markers. Histopathological examination of the kidney confirmed these results.

CONCLUSION

In conclusion, this study indicates that celecoxib may be a promising drug for clinical use as a nephroprotectant against cisplatin-induced nephrotoxicity.

Amelioration of doxorubicin-induced cardiotoxicity by deferiprone in rats

The therapeutic usefulness of doxorubicin (Dox), an anthracycline antibiotic used as an anticancer agent, is limited by its cardiotoxicity. Dox-induced cardiotoxicity is mainly attributed to accumulation of reactive oxygen species and interaction of Dox with cellular iron metabolism. The present study investigated the effects of the iron chelator deferiprone (Def) against Dox-induced cardiotoxicity in rats. Dox (15 mg/kg) was injected intraperitoneally as a single dose, and Def (10 mg/kg) was administered orally for 10 days. Dox showed cardiotoxicity as evidenced by increased heart rate, elevated ST segment, prolonged QTc interval, and increased T wave amplitude. In addition, Dox enhanced aconitine cardiotoxicity by decreasing its dose, producing ventricular tachycardia. Administration of Def significantly attenuated Dox-induced electrocardiographic changes. Cardiotoxicity of Dox was confirmed biochemically by a significant elevation in serum creatine kinase-MB and lactate dehydrogenase activities as well as by myocardial malondialdehyde and reduced glutathione contents. Moreover, Dox caused a significant decrease in myocardial superoxide dismutase activity. Administration of Def significantly attenuated the biochemical changes. These results suggest that Def might be a potential cardioprotective agent against Dox-induced cardiotoxicity.

Thymoquinone-induced relaxation of isolated rat pulmonary artery

AIM OF THE STUDY

The effect of thymoquinone (TQ), the main constituent of the volatile oil of black seed (Nigella sativa L. family Ranunculaceae), on the isolated rat pulmonary arterial rings was investigated.

MATERIALS AND METHODS

Isolated rat pulmonary arterial rings were precontracted with phenylephrine and concentration-response curves to TQ were constructed. The effects of different receptors antagonists or enzyme inhibitors were examined.

RESULTS

TQ caused a concentration-dependent decrease in the tension of the pulmonary arterial rings precontracted by phenylephrine. The effects of TQ were not influenced by pretreatment of the rings with propranolol (a non-selective beta-blocker), atropine (a non-selective blocker for muscarinic receptors), theophylline (an adenosine receptor antagonist), indomethacin (a cyclooxygenase inhibitor), L-NAME (a NO synthase inhibitor), methylene blue (an inhibitor of soluble guanylyl cyclase) and nifedipine (a Ca(2+) channel blocker). The effects of TQ were significantly potentiated by bosentan (an ET(A)/ET(B) receptor antagonist). The effects of TQ were slightly abolished by pretreatment of the rings with glibenclamide (a non-selective blocker of ATP-sensitive K+ channels). TQ totally abolished the pressor effects of serotonin and phenylephrine on the isolated rat pulmonary arterial rings.

CONCLUSION

The results of the present study suggest that TQ-induced relaxation of the precontracted pulmonary artery is probably mediated, at least in part, by activation of ATP-sensitive potassium channels and possibly by non-competitive blocking of serotonin, alpha1 and endothelin receptors.

Effect of bosentan (ETA/ETB receptor antagonist) on metabolic changes during stress and diabetes

Elevated plasma ET-1 levels have been reported in several conditions such as stress and diabetes. ET-1 is found to cause insulin resistance and to stimulate liver glycogenolysis. The question arises whether ET-1 has a role in the metabolic changes occurring in such conditions. To test this, we studied the possible effect of the endothelin receptor antagonist, bosentan (50 and 100 mg kg(-1)) on serum glucose and insulin levels as well as on liver glycogen contents in normoglycemic stressed animals. In addition, the effect of bosentan on serum glucose and insulin levels in both mild and severely diabetic rats and its effect on insulin-induced hypoglycemia were also determined. Restraining water immersion stress was used as a model for severe stress reported to elevate plasma ET-1 level. Mild diabetes was induced in rats by intraperitoneal injection of a low dose of streptozotocin (38 mg kg(-1)) while severe diabetes was induced by intraperitoneal injection of a higher dose of streptozotocin (45 mg kg(-1)). Bosentan partially prevented stress-induced both hyperglycemia and decrease in glycogen content while it completely blocked the stress-induced decrease in insulin level in normoglycemic stressed rats. Bosentan also decreased serum glucose level without any effect on insulin secretion in mild diabetic rats and potentiated the hypoglycemic action of insulin.