Effects of furosemide and tadalafil in both conventional and nanoforms against adenine-induced chronic renal failure in rats.

BACKGROUND: Chronic renal failure (CRF) is a progressive loss of renal function that lead to reduced sodium filtration and inappropriate suppression of tubular reabsorption that ultimately leads to volume expansion. The aim of this study was to study the efficacy of furosemide and tadalafil nanoforms compared to conventional forms against adenine-induced CRF rat-model. METHODS: Addition of 0.75% adenine to the diet of rats for 4 weeks gained general acceptance as a model to study kidney damage as this intervention mimicked most of the structural and functional changes seen in human chronic kidney disease Urine analysis, histopathological changes and immunohistochemical expression of caspase-3 and interleukin-1 beta (IL-1ß) in renal tissues were performed. RESULTS: Our results showed that the combination of tadalafil and furosemide using conventional and nanoparticle formulations had better renoprotective effect than individual drugs. This was demonstrated by improvement of urinary, serum and renal tissue markers as indicative of organ damage. This was also reflected on the reduction of tubular expression of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL). Immunohistochemical studies showed that the deteriorated renal cellular changes indicated by increased expression of caspase-3 and IL-1ß were greatly improved by the combined treatment particularly with the nanoforms. CONCLUSIONS: The nanoforms of both furosemide and tadalafil had greater renopreventive effects compared with conventional forms against adenine-induced CRF in rats.

Effect of stevia aqueous extract on the antidiabetic activity of saxagliptin in diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Stevia rebaudiana Bertoni is a perennial herb that belongs to the Asteraceae family. It is a natural sweetener plant known as "Sweet Leaf", "Sweet Herbs" and "Honey Leaf", which is estimated to be 300 times more sweetening than sugar cane. Stevia has been used as a traditional treatment for diabetes in many countries for hundreds of years. Several animal studies referred to the antihyperglycemic activity of stevia. However, the combined use of stevia with saxagliptin has not been studied so far, so this study has been done. The aim of the present study was to evaluate the antihyperglycemic effect of stevia alone and in combination with saxagliptin. MATERIALS AND METHODS: Diabetes was induced in rats by i.p. injection of streptozotocin and nicotinamide. Animals were divided into five groups, each contains eight rats. Group I: included negative controland group II: included diabetic control that received saline. Group III: included diabetic rats that received 400 mg/kg/day stevia aqueous extract. Group IV: included diabetic rats that received saxagliptin 10 mg/kg/day. Group V: included diabetic rats that received stevia 400 mg/kg + saxagliptin 10 mg/kg. Food and water intake were measured daily while body weight was measured weekly. After 3 weeks animals were sacrificed and blood and tissue samples were collected. Fasting blood glucose (FBG), serum insulin, serum dipeptidylepeptidase-4 (DPP-4), TC, TGs, LDL, HDL, GSH and MDA were measured in treated and control rats by colorimetric and ELISA methods. RESULTS: Both stevia and saxagliptin significantly reduced food, water intake, body weight and FBG. Stevia with saxagliptin produced more significant decrease in FBG. While serum insulin increased significantly in stevia, saxagliptin treated groups and their combination. Serum DPP-4 decreased significantly in all treated groups, concerning lipid profile, stevia and saxagliptin notably lowered TC, TGs, and LDL and increased HDL. Both stevia and saxagliptin remarkably decreased MDA and increased GSH compared to diabetic rats. In addition, stevia significantly improved the antidiabetic effects of saxagliptin. CONCLUSION: Stevia has an antihyperglycemic effect and could enhance the antidiabetic activity of saxagliptin. DPP-4 attenuation, antihyperlipidemic and antioxidant activity as well as improvement of insulin sensitivity may be involved in the antidiabetic action of stevia.

Resveratrol as an effective adjuvant therapy in the management of rheumatoid arthritis: a clinical study.

Resveratrol (RSV), a naturally occurring polyphenol, has been found to have potent antioxidant, anti-inflammatory, and anticancer effects. Recently, RSV was reported as a new potential agent to suppress inflammation of collagen-induced arthritis in a mouse model. Nevertheless, the clinical benefits of RSV in the management of rheumatoid arthritis (RA) were not studied. This randomized controlled clinical trial aims to shed some light on the therapeutic benefits of RSV in the treatment of RA in patients with different stages of the disease activity. In this randomized controlled clinical trial, 100 RA patients (68 female, 32 male) were enrolled randomly and divided into two groups, each of 50 patients: an RSV-treated group that received a daily RSV capsule of 1 g with the conventional treatment for 3 months and a control group that just received the regular treatment. The clinical and biochemical markers of RA in both groups were assessed. It was found that the clinical markers (i.e., the 28-joint count for swelling and tenderness) and the disease activity score assessment for 28 joints were significantly lowered in the RSV-treated group. Moreover, serum levels of certain biochemical markers (i.e., C-reactive protein, erythrocyte sedimentation rate, undercarboxylated osteocalcin, matrix metalloproteinase-3, tumor necrosis factor alpha, and interleukin-6) were also significantly decreased in RSV-treated patients. The current study suggests the addition of RSV as an adjuvant to the conventional antirheumatic drugs.

A potential mechanism for the ameliorative effect of thymoquinone on pentylenetetrazole-induced kindling and cognitive impairments in mice.

Cognitive dysfunction is commonly observed in epileptic patients. Pentylenetetrazole (PTZ) kindling is a well established animal model which simulates clinical epilepsy. This study evaluated the potential role of glutamate, oxidative stress and nitric oxide (NO) overproduction in pentylenetetrazole (PTZ)-induced kindling and associated cognitive impairments in mice and effect of thymoquinone on these parameters. Repeated treatment of mice with a subconvulsive dose of PTZ (35mg/kg i.p.) once every alternate-day for 12 injections induced kindling. PTZ-kindled mice showed learning and memory impairments as assessed by acquisition and probe trials of Morris water maze and step-through latency of passive avoidance tests. Concurrently, the brain glutamate, malondialdehyde and nitrite levels were increased while the brain intracellular reduced glutathione level and glutathione peroxidase activity were decreased in PTZ-kindled mice. Also, the brain inducible but not neuronal NO synthase mRNA and protein expressions were increased in PTZ-kindled mice. Treatment of mice with thymoquinonne (5, 10 and 20mg/kg i.p.) along with alternate-day subconvulsive dose of PTZ produced dose-dependent protection against PTZ-induced kindling and learning and memory impairments. Moreover, treatment of mice with thymoquinonne (20mg/kg) inhibited the biochemical alterations induced by PTZ in the brain except the elevation of brain glutamate level. The associated increase in brain inducible NO synthase mRNA and protein expressions were also inhibited. These results suggest that glutamate, and subsequent oxidative stress and NO overproduction, via inducible NO synthase, play an important role in the pathophysiology of PTZ-induced kindling and cognitive impairments in mice. Thymoquinone dose-dependently protects against PTZ-induced kindling and cognitive impairments. Inhibition of PTZ-induced brain oxidative stress and NO overproduction, via increase the expression and activity of inducible NO synthase, may play an important role in thymoquinone action.

Protective effect of citicoline against aluminum-induced cognitive impairments in rats.

The potential protective effect of citicoline on aluminum chloride-induced cognitive deficits was investigated in rats. In a Morris water maze, administration of aluminum chloride to rats for 90 days resulted in increased escape latency to reach the platform and decreased swimming speed in acquisition trials. Similarly, in probe trials, the time required to reach the hidden platform was increased and the time spent in the target quadrant was reduced. Also, administration of aluminum chloride to rats for 90 days increased the reference and working memory errors and time required to end the task in the radial arm maze. In addition, this treatment decreased the step-through latency in the passive avoidance test. Concurrently, treatment of rats with aluminum chloride for 90 days increased hippocampal glutamate, malondialdehyde, and nitrite levels and decreased intracellular reduced glutathione level. In the citicoline-treated group, aluminum chloride-induced learning and memory impairments as assessed by the Morris water maze, radial arm maze, and passive avoidance tests were inhibited. At the same time, treatment of rats with citicoline prevented the biochemical alterations induced by aluminum chloride in the hippocampus. It can be concluded that elevation of hippocampal glutamate level with consequent oxidative stress and nitric oxide (NO) overproduction may play an important role in aluminum-induced cognitive impairments. Also, our results suggest, for the first time, that citicoline can protect against the development of these cognitive deficits through inhibition of aluminum-induced elevation of glutamate level, oxidative stress, and NO overproduction in the hippocampus.

Vitamin K homologs as potential biomarkers for disease activity in patients with rheumatoid arthritis.

The aim of this study was to evaluate the possible role of vitamin K homologs as potential biomarkers for disease activity in patients with rheumatoid arthritis (RA). In this study, 42 patients with RA and 40 healthy controls were enrolled. Serum levels of vitamin K homologs were measured using a high-performance liquid chromatography-fluorescence method. Different biochemical and clinical markers for disease activity were measured and correlated with serum levels of vitamin K homologs. There were no significant differences between RA patients and healthy subjects in demographic data. Patients with RA showed significantly higher levels of biochemical markers compared with healthy subjects (p < 0.001). These markers included rheumatoid factor (RF), anticyclic citrullinated polypeptide (anti-CCP), undercarboxylated osteocalcin (ucOC), matrix metalloproteinase (MMP-3), C-reactive protein (CRP), and disease activity score assessing 28 joints with erythrocyte sedimentation rate (DAS28-ESR). In addition, serum levels of vitamin K homologs were reduced in RA patients, and the levels of menaquinone-4 (MK-4) and menaquinone-7 (MK-7) were moderately to strongly inversely correlated with the clinical articular features in RA patients, whereas phylloquinone (PK) levels were weakly correlated. Serum levels of MK-4, MK-7 and PK were strongly inversely correlated with ucOC, MMP-3 and DAS28-ESR in RA patients. In contrast, serum levels of MK-4, MK-7 and PK were weakly correlated with CRP, RF and anti-CCP. These results suggest that serum levels of vitamin K homologs may be considered as potential biomarkers for disease activity. In addition, the results confirm the role of vitamin K deficiency in the etiology of RA.

Reactive oxygen and nitrogen species in patients with rheumatoid arthritis as potential biomarkers for disease activity and the role of antioxidants.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have distinct contribution to the destructive, proliferative synovitis of rheumatoid arthritis (RA) and play a prominent role in cell-signaling events. However, few studies had clarified the role of individual ROS and RNS in the etiopathogenesis of RA. To date, most of the studies were concerned with the measurement of the total oxidative and nitrative stress levels in RA. The aim of this study was to monitor the levels of individual ROS and RNS to emphasize the role that each plays in the pathogenesis of RA and their usefulness as possible biomarkers for the disease activity. In addition, the effect of an antioxidant (ascorbic acid), added to the treatment regimen, on the levels of ROS, RNS and disease activity has been evaluated. Forty-two Saudi RA patients and 40 healthy controls of both genders were included in this study. Serum levels of six different ROS and three different RNS were measured using specific fluorescent probes. The ROS included the hydroxyl radical ((•)OH), the superoxide anion (O2(•-)), hydrogen peroxide (H2O2), the singlet oxygen ((1)O2), the hypochlorite radical (OHCl(•)), and the peroxyl radical (ROO(•)). The RNS included nitric oxide (NO(•)), nitrogen dioxide (ONO-) and peroxynitrite (ONOO-). The main clinical and biochemical markers for disease activity were assessed and correlated with ROS and RNS levels. The clinical markers included the 28 swollen joint count (SJC-28), the 28-tender joint count (TJC-28), morning stiffness and symmetric arthritis, in addition to the disease activity score assessing 28 joints with erythrocyte sedimentation rate (DAS28-ESR). The biochemical markers included undercarboxylated osteocalcin (ucOC), matrix metalloproteinase (MMP-3), ESR, C-reactive protein (CRP), rheumatoid factor (RF) and anticyclic citrullinated polypeptide (Anti-CCP). Ascorbic acid (1mg/day) was added as an antioxidant to the regular treatment regimen of RA patients for two months, and the levels of ROS and RNS, as well as disease activity were re-evaluated. The results have shown significant higher serum levels of individual ROS and RNS in RA patients compared with healthy subjects. Moreover, this study might be the first to report strong positive correlations between most of the reactive species and the clinical and biochemical markers of RA. Interestingly, the addition of ascorbic acid had significantly reduced the levels of all ROS and RNS in RA patients. In conclusion, the role of oxidative and nitrative stress in the pathogenesis of RA has been confirmed by this study. Serum levels of ROS and RNS may effectively serve as biomarkers for monitoring disease progression. Finally, the addition of an antioxidant, such as ascorbic acid, in the management of RA may be of a great value.

Menaquinone-7 as a novel pharmacological therapy in the treatment of rheumatoid arthritis: A clinical study.

Menaquinones (MKs) have been reported to induce apoptosis in rheumatoid arthritis (RA) synovial cells. Recently, menaquinone-4 (MK-4) was proven as a new potential agent for the treatment of RA. However, menaquinone-7 (MK-7) has greater bioavailability and efficacy than MK-4 after oral administration. Yet, the therapeutic benefits of MK-7 in the management of patients with RA have never been addressed. This study was designed to clarify the therapeutic role of MK-7 added to normal therapeutic regimen of RA in patients with different stages of the disease with a clinical follow up through a randomized clinical trial. In a cross sectional study, 84 RA patients (24 male, 60 female) (average age=47.2 years) were enrolled in this study. The patients were divided into MK-7 treated group (n=42) and MK-7 naïve group (n=42). MK-7 capsules were administered in a dose of 100µg/day for three months in the first group without changing in other medications. The clinical and biochemical markers on RA patients treated with MK-7 and naïve group were assessed. In MK-7 treated group, serum concentrations of MK-7 were monitored before and after three months of MK-7 administration. In the cross sectional study, a significant decrease in MK-7 treated group for the levels of undercarboxylated osteocalcin (ucOC), erythrocyte sedimentation rate (ESR), disease activity score assessing 28 joints with ESR (DAS28-ESR), C-reactive protein (CRP) and matrix metalloproteinase (MMP-3) was found. In MK-7 treated group, a marked decrease in RA clinical and biochemical markers for moderate and good response compared to non-responders was observed in ucOC, ESR and DAS28-ESR. A marked increase in the levels of MK-7 for the moderate and good responders compared to non-responders was observed. The results suggest that MK-7 improves disease activity in RA patients. Therefore, MK-7 represents a new promising agent for RA in combination therapy with other disease modifying antirheumatic drugs.

Protective effect of Nigella sativa oil against tramadol-induced tolerance and dependence in mice: role of nitric oxide and oxidative stress.

Nigella sativa seed extracts and its oil have been exploited for their various health benefits. In this study, the effects of N. sativa oil on tramadol-induced tolerance and dependence and possible mechanism(s) of these effects were investigated, for the first time, in mice. Repeated administration of N. sativa oil (4 ml/kg, p.o.) along with tramadol (50mg/kg, s.c.) inhibited the development of tramadol tolerance, as measured by the hot plate test, and dependence as assessed by naloxone (5mg/kg, i.p.)-precipitated withdrawal manifestations. Concomitantly, nitric oxide overproduction and increase in brain malondialdehyde level induced by repeated administration of tramadol to mice or by administration of naloxone to tramadol-dependent mice were inhibited by co-administration of the oil. Also, the decrease in brain intracellular reduced glutathione level and glutathione peroxidase activity induced by both treatments was inhibited by co-administration of the oil. The increase in brain glutamate level induced by both treatments was not inhibited by concurrent administration of the oil. The inhibitory effect of N. sativa oil on tramadol-induced tolerance and dependence was enhanced by concurrent i.p. administration of the NMDA receptor antagonist, dizocilpine (0.25mg/kg). Also, the inhibitory effect of the oil on naloxone-induced biochemical alterations in tramadol-dependent mice was enhanced by concurrent administration of dizocilpine. Similarly, concurrent i.p. administration of the NO synthase inhibitor, L-N(G)-nitroarginine methyl ester (10mg/kg) or the antioxidant, N-acetylcysteine (50mg/kg) enhanced these inhibitory effects of N. sativa oil. On the other hand, these effects were antagonized by concurrent i.p. administration of the NO precursor, L-arginine (300 mg/kg). These results provide evidence that N. sativa oil appears to have a therapeutic potential in tramadol tolerance and dependence through blockade of NO overproduction and oxidative stress induced by the drug.

Blockade of nitric oxide overproduction and oxidative stress by Nigella sativa oil attenuates morphine-induced tolerance and dependence in mice.

The effects of Nigella sativa oil on morphine-induced tolerance and dependence in mice and possible mechanism(s) of these effects were investigated, for the first time, in this study. Repeated administration of Nigella sativa oil (4 ml/kg, p.o.) along with morphine (5 mg/kg, s.c.) attenuated the development of tolerance, as measured by the hot plate test, and dependence, as assessed by naloxone (5 mg/kg, i.p.)-precipitated withdrawal manifestations. Concomitantly, nitric oxide overproduction and increase in brain malondialdehyde level induced by repeated administration of morphine to mice or by administration of naloxone to morphine-dependent mice were inhibited by co-administration of the oil. Also, the decrease in brain intracellular reduced glutathione level and glutathione peroxidase activity induced by both treatments were inhibited by co-administration of the oil. The increase in brain glutamate level induced by both treatments was not inhibited by concurrent administration of the oil. The inhibitory effect of the oil on morphine-induced tolerance and dependence and on naloxone-induced biochemical alterations in morphine-dependent mice was enhanced by concurrent i.p. administration of the NMDA receptor antagonist, dizocilpine (0.25 mg/kg). Similarly, concurrent i.p. administration of the NO synthase inhibitors; L-N (G)-nitroarginine methyl ester (10 mg/kg), aminoguanidine (20 mg/kg) and 7-nitroindazole (25 mg/kg) or the antioxidant, N-acetylcysteine (50 mg/kg) enhanced this inhibitory effect of the oil. On the other hand, this effect was antagonized by concurrent i.p. administration of the nitric oxide precursor, L-arginine (300 mg/kg). These results provide evidence that Nigella sativa oil, through inhibition of morphine-induced NO overproduction and oxidative stress, appears to have a therapeutic potential in opioid tolerance and dependence.