Nephroprotective effects of diminazene on doxorubicin-induced acute kidney injury in rats

This study aimed to investigate the potential protective effects of diminazene, an activator of angiotensin II converting enzyme (ACE2), on kidney function and structure in rats with acute kidney injury (AKI) induced by the anticancer drug doxorubicin (DOX). The impact of diminazene was compared to that of two other drugs: the ACE inhibitor lisinopril and the angiotensin II type 1 (AT1) receptor blocker valsartan. Rats were subjected to a single intraperitoneal injection of DOX (13.5 mg/kg) on the 5th day, either alone or in combination with diminazene (15 mg/kg/day), lisinopril (10 mg/kg/day), or valsartan (30 mg/kg/day) for 8 consecutive days. Various markers related to kidney function, oxidative stress, and inflammation were measured in plasma and urine. Additionally, kidney tissues were assessed histopathologically. DOX-induced nephrotoxicity was confirmed by elevated levels of plasma urea, creatinine, and neutrophil gelatinase-associated lipocalin (NGAL). DOX also led to increased urinary N-acetyl-β-D-glucosaminidase (NAG) activity and decreased creatinine clearance, albumin levels, and osmolality. Moreover, DOX caused a reduction in renal oxidative stress markers, including superoxide dismutase (SOD), glutathione reductase (GR), and catalase activities, while increasing malondialdehyde (MDA) levels. It also raised plasma inflammatory markers, tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β). Concurrently administering diminazene significantly mitigated these DOX-induced changes, including histopathological alterations like renal tubule necrosis, tubular casts, shrunken glomeruli, and increased renal fibrosis. Similar protective effects were observed with lisinopril and valsartan. These protective effects, at least in part, appear to result from the anti-inflammatory and antioxidant properties of these drugs. In summary, this study suggests that the administration of diminazene, lisinopril, or valsartan had comparable effects in ameliorating the biochemical and histopathological aspects of DOX-induced acute kidney injury in rats.

Potentially Harmful Drug-Drug Interactions and Their Associated Factors Among Hospitalized Cardiac Patients: A Cross-Sectional Study

BACKGROUND

Cardiovascular diseases are responsible for a significant proportion of mortalities worldwide. Elderly patients are the most affected by cardiovascular diseases, and because of factors such as polypharmacy, multimorbidity, and age-related changes in drug availability and metabolism, they are highly susceptible to the occurrence of drug-drug interactions. Drug-drug interactions are among the many drug-related problems leading to negative outcomes among inpatients and outpatients. Thus, it is important to investigate the prevalence, involved drugs, and factors related to potential drug-drug interactions (pDDIs) to properly optimize pharmacotherapy regimens for these patients.

OBJECTIVE

We aimed to determine the prevalence of pDDIs, drugs most frequently implicated, and significant predictors associated with these interactions among hospitalized patients in the Cardiology Unit at Sultan Qaboos University Hospital in Muscat, Oman.

METHODS

This retrospective cross-sectional study included 215 patients. Micromedex Drug-Reax® was used to identify pDDIs. Data extracted from patients' medical records were collected and analyzed. Univariable and multivariable linear regression was applied to determine the predictors associated with the observed pDDIs.

RESULTS

A total of 2057 pDDIs were identified, with a median of nine (5-12) pDDIs per patient. Patients with at least one pDDI accounted for 97.2% of all the included patients. The majority of pDDIs were of major severity (52.6%), fair level of documentation (45.5%), and pharmacodynamic basis (55.9%). Potential drug-drug interactions between atorvastatin and clopidogrel were the most frequently observed (9%). Of all the detected pDDIs, around 79.6% of them included at least one antiplatelet drug. Having diabetes mellitus as a comorbidity (B = 2.564, p < 0.001) and the number of drugs taken during the hospitalization period (B = 0.562, p < 0.001) were factors positively associated with the frequency of pDDIs.

CONCLUSIONS

Potential drug-drug interactions were highly prevalent among hospitalized cardiac patients at Sultan Qaboos University Hospital, Muscat, Oman. Patients having diabetes as a comorbidity and with a high number of administered drugs were at a higher risk of an increased number of pDDIs.

Prescription Patterns of Analgesic Drugs in the Management of Pain Among Palliative Care Patients at a Tertiary Hospital in Oman: A Retrospective Observational Study

Objectives Analgesic drugs are commonly used to alleviate the pain experienced by palliative care (PC) patients. Thus, we sought to determine the prescription patterns of analgesic drugs in the management of pain among haematology and oncology palliative care patients at Sultan Qaboos University Hospital (SQUH) and then see if they were following the World Health Organization (WHO) guidelines. Methods A retrospective observational cross-sectional study was conducted, and adult PC patients prescribed analgesics for pain relief between January 2018 and January 2021 at SQUH constituted the sample. Data were collected from patients' electronic medical records using the SQUH TrakCare system. The data was then presented descriptively using graphs and tables. Results Data from 200 PC patients were analyzed. Breast cancer was the most common malignancy, with 73 (36.5%) patients diagnosed with it. Severe pain was the most reported degree of pain, with exactly 100 (50.0%) patients experiencing it. More patients experienced mild pain than moderate pain. Opioids were the most prescribed analgesics, followed by analgesics and antipyretics, anticonvulsants, and finally non-steroidal anti-inflammatory drugs (NSAIDs). Paracetamol was the most prescribed analgesic for pain overall, with 127 (63.5%) patients utilizing it. For severe pain, morphine was the most prescribed analgesic, with 65.0% of patients using it. Fentanyl and pregabalin, the strongest two analgesics, increased in prescription for severe pain compared to mild and moderate pain, with both being prescribed to 23.0% of patients suffering from severe pain. The oral route of administration was the most prescribed, with 128 (64.0%) utilizing it. Conclusion This study showed the prescription patterns of analgesic drugs for palliative care patients at SQUH. The findings were similar to those of other studies, though there were some differences. The prescription patterns of analgesic drugs prescribed for the various pain levels among PC patients were found to be in accordance with the WHO guidelines.

Metabolic Side Effects of Olanzapine in Patients With Psychotic Disorders in Oman: A Retrospective Cohort Study

We evaluated the impact of olanzapine on metabolic changes in patients with psychotic disorders. This was a retrospective cohort study involving patients prescribed olanzapine and attending Sultan Qaboos University Hospital (Muscat, Oman). Patients were followed up retrospectively from March 2006 until April 2021. Cardiovascular treatment targets were evaluated as per the 2019 European Society of Cardiology guidelines. We enrolled 253 patients (mean age: 40±17 years). Olanzapine monotherapy was associated with increased body weight (+8 kg; 95% confidence interval (CI): 6-9; P < .001), body mass index (+3 kg/m²; 95% CI: 2-4; P < .001), total cholesterol (+.4 mmol/L; 95% CI: .3-.5; P < .001), low-density lipoprotein cholesterol (LDL-C) (+.3 mmol/L; 95% CI: .1-.4; P < .001), fasting triglycerides (+.2 mmol/L; 95% CI: .1-.3; P<.001), fasting glucose (+.6 mmol/L; 95% CI: .4-.7; P< .001), HbA1c (+.3%; 95% CI: .2-.4; P < .001), systolic blood pressure (BP) (+9 mmHg; 95% CI: 6-12; P < .001) and diastolic BP (+4 mmHg; 95% CI: 2-6; P < .001) levels. Cardiovascular therapeutic goals were attained in 38% (n = 97), 61% (n = 154), 71% (n = 180), and 59% (n = 150) for LDL-C, non-high-density lipoprotein cholesterol, triglycerides, and BP, respectively. Olanzapine was associated with adverse metabolic changes. Therefore, many patients were not at their target cardiovascular treatment goals.

The Effects of Furosemide on Behavioral and Hormonal Parameters in Male and Female Mice Subjected to Immobilization and Cold-Water Stress

Introduction

The diuretic agent furosemide (FUR, 25 and 50 mg/kg) has been shown in a single report to act as an anti-stressor agent in two models of acute stress in mice, viz. electric foot-shock stress and immobilization (IMS). The present work aimed to investigate the possible anti-stressor action of FUR on two models of acute stress in mice, cold-water stress (CWS) and IMS, and tried to determine whether gender has any impact on the effect of FUR.

Methods

FUR (40 mg/kg) was injected intraperitoneally, and after 30 minutes, mice were subjected to CWS (4°C for three minutes) or IMS (fixing movement for two and a half hrs using adhesive tape). Motor and exploratory activities, neuromuscular coordination, and thermal nociception were then tested. Blood was collected from the mice and used to measure the concentrations of three stress hormones (corticosterone, epinephrine and prolactin).

Results

Mice subjected to CWS and IMS had significantly reduced motor and exploratory activities, neuromuscular coordination, and increased nociception. CWS and IMS also significantly increased the plasma concentrations of the three hormones. FUR pretreatment significantly mitigated these stress-induced hormonal changes. There was no significant sex difference when CWS or IMS was applied.

Discussion

IMS and CWS stimuli in male and female mice caused significant elevations in the plasma concentrations of corticosterone, epinephrine, and prolactin, accompanied by a significant reduction of motor and exploratory activities, neuromuscular coordination, and thermal nociception. There were no sex differences when IMS was applied. In stressed mice, prior administration of FUR (40 mg/kg) significantly decreased the concentrations of stress hormones, and this effect significantly mitigated the stress-induced behavioural and motor changes.

The Effect of Metformin in Diabetic and Non-Diabetic Rats with Experimentally-Induced Chronic Kidney Disease

This work aimed to investigate whether treatment with the antidiabetic drug metformin would affect adenine-induced chronic kidney disease (CKD) in non-diabetic rats and rats with streptozotocin (STZ)-induced diabetes. Rats were randomly divided into eight groups, and given either normal feed, or feed mixed with adenine (0.25% w/w, for five weeks) to induce CKD. Some of these groups were also simultaneously treated orally with metformin (200 mg/kg/day). Rats given adenine showed the typical signs of CKD that included detrimental changes in several physiological and traditional and novel biochemical biomarkers in plasma urine and kidney homogenates such as albumin/creatinine ratio, N-acetyl-beta-D-glucosaminidase, neutrophil gelatinase-associated lipocalin, 8-isoprostane, adiponectin, cystatin C, as well as plasma urea, creatinine, uric acid, indoxyl sulfate, calcium, and phosphorus. Several indices of inflammation and oxidative stress, and renal nuclear factor-κB and nuclear factor erythroid 2-related factor 2 levels were also measured. Histopathologically, adenine caused renal tubular necrosis and fibrosis. The activation of the intracellular mitogen-activated protein kinase signaling pathway was inhibited in the groups that received metformin and STZ together, with or without adenine induced-CKD. Induction of diabetes worsened most of the actions induced by adenine. Metformin significantly ameliorated the renal actions induced by adenine and STZ when these were given singly, and more so when given together. The results suggest that metformin can be a useful drug in attenuating the progression of CKD in both diabetic and non-diabetic rats.

Effects of repeated increasing doses of cisplatin as models of acute kidney injury and chronic kidney disease in rats

Cisplatin (CP) is nephrotoxic, and this side effect is used as an animal model for acute kidney injury (AKI). Earlier research has been focused on CP-induced AKI, with relatively little attention being paid to its ability to progress to chronic kidney disease (CKD) on repeated administration. We aimed here to test the dose dependency of its nephrotoxic actions by comparing various physiological, biochemical, molecular, and histopathological indices using repeated increasing doses of CP in rats. Furthermore, we investigated whether these doses of CP would result in the development of CKD. Biochemical, molecular, and histopathological measurements were conducted in plasma, urine, and/or kidneys of rats treated with increasing doses of CP at 1.6, 3.2, and 4.8 mg kg-1 weekly for four consecutive weeks. These doses induced significant and dose-dependent elevations in most of the measured renal indices. These included increased renal fibrosis, as suggested histopathologically and biochemically by the significant increase in transforming growth factor-β1, significant decrease in actin alpha 2, and variable actions of collagen I and IV. CP also dose-dependently increased nuclear factor (erythroid-derived 2)-like 2 and caspase-3. Multiple repeated doses of CP (1.6 to 4.8 mg kg-1) induced multiple episodes of AKI, leading to CKD after the 4th weekly dose and confirmed that this dosage regimen could be used as an experimental animal model of AKI progressing to CKD. These actions were driven by inflammation, oxidative, and nitrosative stress.

Effect of concomitant treatment of curcumin and melatonin on cisplatin-induced nephrotoxicity in rats

Cisplatin (CP) is a potent anticancer drug used to treat solid tumors. Its use, however, is dose-limited by its nephrotoxicity. We aimed to compare the effect of melatonin and curcumin given singly, with that of a combination of these two agents on CP-induced nephrotoxicity in rats. CP (6 mg/kg, given once intraperitoneally) induced nephrotoxicity as evidenced by several significant adverse physiological, biochemical and histopathological actions that included a reduction in body weight, increased urine production, and significant alterations in some conventional and novel renal damage indices in plasma, urine and kidneys. CP also elevated several pro-inflammatory cytokines and caused renal oxidative/nitrosative stress. Supplementation with either curcumin (200 mg/kg) or melatonin (10 mg /kg) given singly by oral gavage for eight consecutive days prior to CP injection and four days thereafter, significantly mitigated the adverse renal effects of CP, by attenuating the pro-inflammatory and apoptotic mediators and improving antioxidant competence in renal tissues of CP- treated rats. When curcumin and melatonin were given together, the ameliorative effect was augmented in some of the measured indices e.g. tumor necrosis factor alpha, cystatin C, uric acid, phosphorus in plasma and, urine creatinine and creatinine clearance. Renal platinum concertation was reduced more with curcumin than that with melatonin, while the reduction was maximized when both melatonin and curcumin were given. Pending further pharmacological and toxicological studies, a combination of these two agents is likely to be mor effective in mitigating the adverse renal effects of CP administered to cancer patients.

Gum arabic reduces inflammation, oxidative, and nitrosative stress in the gastrointestinal tract of mice with chronic kidney disease

The aim of this study was to investigate some biochemical indices of inflammation and oxidative and nitrosative stresses in the gastrointestinal tract of mice with experimental chronic kidney disease (CKD) and treated with gum arabic (GA). Male CD1 mice (n = 28) were randomly distributed into four groups and treated for four consecutive weeks: group 1: Control: received the same diet without treatment until the end of the study; group 2: Adenine: switched to a powder diet containing adenine (0.2% w/w in feed); group 3: Gum acacia (GA): given normal feed and GA in drinking water at a concentration of 15% w/v; and group 4: Adenine + GA: given adenine in the feed as in the second group plus GA in the drinking water at concentration of 15% w/v. CKD was induced to mice by adenine feeding and concomitantly treated with the prebiotic dietary fiber gum acacia, GA (15% in drinking water). Duodenal mucosa from CKD mice had significantly higher concentrations of TNF-alfa, IL- 6, and TGF-beta-1 and lipid peroxidation. Moreover, low concentrations of IL-10, some antioxidants (catalase, glutathione reductase, total antioxidant capacity, and superoxide dismutase), and nuclear factor erythroid 2-related factor 2 were found in the duodenum. The levels of nitrosative stress (nitrite, nitrate, and total nitrate) were significantly increased by CKD, as well as the concentrations of ammonia and urea creatinine in the cecal content. Concomitant GA treatment significantly mitigated these harmful effects. Taken together, GA reduces inflammation and duodenal oxidative and nitrosative stress in the gastrointestinal tract of mice with CKD.

Effect of levosimendan, an inodilator, on streptozotocin-induced diabetic nephropathy in rats

This study examined the effect of levosimendan on streptozotocin-induced early diabetic nephropathy. Rats were distributed into four groups and treated for six weeks. The first and third group received either vehicle or levosimendan (1 mg/kg/day) for the last three weeks, respectively. The second and fourth groups were rendered diabetic by a single intraperitoneal injection of streptozotocin (60 mg/kg) and were treated as the first and third groups, respectively. In the untreated diabetic group, there was a significant decrease in body weight, polyuria and hyperglycemia as well as, increased urinary albumin/creatinine ratio (UACR) and N-acetyl-β-D-glucosaminidase (NAG)/creatinine ratio (UNCR) with no change in creatinine clearance. In addition, diabetes was associated with increased oxidative stress as evidenced by reduced plasma total antioxidant capacity (TAC) and catalase activity and increased plasma malondialdhyde (MDA) and the inflammatory marker, tumor necrosis factor-alpha, (TNF-α). Kidneys from streptozotocin-treated rats showed focal clear renal tubular cells affecting proximal convoluted tubules and mild interstitial fibrosis at the cortico-medullary junction. Levosimendan significantly attenuated the streptozotocin-induced physiological and biochemical changes and there was less clear renal tubular cells. This study shows that levosimendan ameliorated some of the changes seen in streptozotocin-induced early diabetic nephropathy in rats. This could be partly due to its antioxidative and anti-inflammatory effects.

The effect of sildenafil on rats with adenine-Induced chronic kidney disease

The erectile dysfunction drug sildenafil has cardiopulmonary protective actions, and a nephroprotective action in cisplatin and ischemia-reperfusion-induced acute kidney injury. Here, we assessed its possible ameliorative action in a model of chronic kidney disease (CKD) using adenine feeding. Eight groups of rats were treated with saline (controls), adenine (0.25% w/w in feed daily for 5 weeks), and oral sildenafil (0.1, 0.5 or 2.5 mg/kg), either alone, or concomitantly with adenine. Urine was collected 24 h after the end of the treatments from all rats and blood pressure measured, followed by collection of blood and kidneys for the measurement of several functional, biochemical and histopathological parameters. Adenine treatment reduced body weight, creatinine renal clearance, and increased water intake and urine output, as well as the plasma concentrations of urea and creatinine, neutrophil gelatinase-associated lipocalin, and N-acetyl-β-D-glucosaminidase activity, and albumin in urine. Adenine also increased the concentrations of the uremic toxins indoxyl sulfate, uric acid and phosphate, and a number of proteins and inflammatory cytokines, and decreased that of several anti - oxidant indices. Renal histopathological markers of damage (inflammation and fibrosis) were significantly increased by adenine. Sildenafil, given simultaneously with adenine, induced a dose - dependent improvements in most of the above parameters, suggesting its possible use as adjunct treatment for CKD in humans.

Gum Acacia Improves Renal Function and Ameliorates Systemic Inflammation, Oxidative and Nitrosative Stress in Streptozotocin-Induced Diabetes in Rats with Adenine-Induced Chronic Kidney Disease

BACKGROUND/AIMS

The effect of treatment with gum acacia (GA), a prebiotic shown previously to ameliorate chronic kidney disease (CKD), in diabetic and non - diabetic rats with adenine - induced CKD has been investigated using several conventional and novel physiological, biochemical, and histopathological parameters.

METHODS

Diabetes mellitus was induced in rats by a single injection of streptozotocin (STZ). Diabetic and non - diabetic rats were randomly divided into several groups, and given either normal food or food mixed with adenine (0.25% w/w, for five weeks) to induce CKD. Some of these groups were also concomitantly treated orally with GA in the drinking water (15% w/w).

RESULTS

Rats fed adenine alone exhibited physiological (decreased body weight, increased food and water intake and urine output), biochemical (increase in urinary albumin/creatinine ratio, plasma urea and, creatinine, indoxyl sulfate and phosphorus), inflammatory biomarkers (increased in neutrophil gelatinase-associated lipocalin, transforming growth factor beta -1, tumor necrosis factor alpha, adiponectin, cystatin C and interleukin-1β), oxidative biomarkers (8-isoprostane, 8 -hydroxy -2-deoxy guanosine), nitrosative stress biomarkers (nitrite and nitrate) and histopathological (increase in tubular necrosis and fibrosis) signs of CKD. STZ - induced diabetes alone worsened most of the renal function tests measured. Administration of adenine in STZ - diabetic rats further worsened the renal damage induced by adenine alone. GA significantly ameliorated the renal actions of adenine and STZ, given either singly or in combination, especially with regards to the histopathological damage.

CONCLUSION

GA is a useful dietary agent in attenuating the progression of CKD in rats with streptozotocin-induced diabetes.

Potassium bromate-induced kidney damage in rats and the effect of gum acacia thereon

Potassium bromate (KBrO₃) is used in many countries in cosmetic and food industries. In this work, we investigated in male Sprague-Dawley rats, the effect of four graded oral doses of KBrO₃ (5, 15, 45 and 135 mg/kg/day for 28 days) on renal function tests, inflammation, oxidative damage, and apoptosis, as well as on histopathology, using several traditional and novel renal injury biomarkers in plasma, urine and renal tissues. We also tested the possible ameliorative action of the renoprotective prebiotic agent gum acacia (GA) on the actions of KBrO₃ when given concomitantly with it in the drinking water at a concentration of 15%^w/v. Taken together, the results indicated that treatment with KBrO₃ at the 45 and 135 mg/kg doses caused a significant dose-dependent nephrotoxicity, as evident by the measured renal structural and functional indices and biomarkers of toxicity. GA co-treatment significantly abated most of the indices and biomarkers of the renal toxicity caused by KBrO₃, suggesting a beneficial effect and its possible inclusion in edible products where KBrO₃ is still used.