Mohammad Ola | King Saud University (original) (raw)

Papers by Mohammad Ola

Asian Journal of Chemistry, 2014

Experimental and Therapeutic Medicine, May 1, 2015

Reactive Oxygen Species in Biology and Human Health, 2016

Journal of chromatographic science, Jan 21, 2016

ITALIC! N-Acetylcysteine (NAC) is the ITALIC! N-acetyl derivative of the amino acidl-cysteine and... more ITALIC! N-Acetylcysteine (NAC) is the ITALIC! N-acetyl derivative of the amino acidl-cysteine and is extensively used as a medicine to treat a variety of diseases. High-throughput ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) method has been developed for the quantitative assessment of ITALIC! N-acetyl-l-cysteine. The method was further applied to study the distribution of the intraperitoneal injected drug into different tissues and plasma of Wistar rats, including liver, kidney, heart, lungs and spleen. The drug was having highest concentration in plasma and liver followed by kidney, lungs, heart and spleen. Method validation studies suggested being linear in the range of 1-15 µg mL(-1)for liver, kidney, heart, lungs and spleen and 1-120 µg mL(-1)for the plasma. The limit of detection and limit of quantitation were found to be 0.20 and 0.66 µg mL(-1), respectively. The recovery studies suggested that in all the cases, the obtained recovery was in the ra...

Arvo Meeting Abstracts, May 1, 2005

AJP Cell Physiology

Taurine is actively transported at the retinal pigment epithelial (RPE) apical membrane in an Na(... more Taurine is actively transported at the retinal pigment epithelial (RPE) apical membrane in an Na(+)- and Cl(-)-dependent manner. Diabetes may alter the function of the taurine transporter. Because nitric oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we asked whether NO would alter the activity of the taurine transporter in cultured ARPE-19 cells. The activity of the transporter was stimulated in the presence of the NO donor 3-morpholinosydnonimine. The stimulatory effects of 3-morpholinosydnonimine were not observed during the initial 16-h treatment; however, stimulation of taurine uptake was elevated dramatically above control values with 20- and 24-h treatments. Kinetic analysis revealed that the stimulation was associated with an increase in the maximal velocity of the transporter with no significant change in the substrate affinity. The NO-induced increase in taurine uptake was inhibited by actinomycin D and cycloheximide. RT-PCR analysis and nuclear run-on assays provided evidence for upregulation of the transporter gene. This study provides the first evidence of an increase in taurine transporter gene expression in human RPE cells cultured under conditions of elevated levels of NO.

... Biol Pharm Bull 2005;28:1172-1176. 14. Haidara M, Khlonssy H, Ammar H, Kassem LA. Im-pact of ... more ... Biol Pharm Bull 2005;28:1172-1176. 14. Haidara M, Khlonssy H, Ammar H, Kassem LA. Im-pact of α-tocopherol and vitamin C on endothelial markers in rats with streptozotocin-induced diabetes. Med Sci Monit 2004;10: 41-46. ... Exp Clin Endocrinol Diab 2001;109:210-216. 16. ...

Neurological research, Jan 17, 2015

Present study aims to investigate the ameliorative effects of naringenin (NG) on experimentally i... more Present study aims to investigate the ameliorative effects of naringenin (NG) on experimentally induced diabetic neuropathy (DN) in rats. Diabetes was induced by single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). Naringenin (25 and 50 mg/kg/day) treatment was started 2 weeks after the diabetes induction and continued for five consecutive weeks. Pain threshold behaviour tests were performed at the end of the treatment. Serum levels of glucose, insulin and pro-inflammatory cytokines were assessed. In sciatic tissues, markers oxidative stress, cytokines and neurotrophic factors were measured. NG treatments showed significant decrease in paw-withdrawal (P < 0.01) and tail-flick latency (P < 0.01). The drug attenuated the diabetic-induced changes in serum glucose, insulin and pro-inflammatory cytokines including tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and interleukin-6 (IL-6). In sciatic nerve, the diabetic-induced alterations in inte...

Journal of Molecular Neuroscience, 2015

Diabetic retinopathy is widely recognized as a neurodegenerative disease of the eye. Increased ox... more Diabetic retinopathy is widely recognized as a neurodegenerative disease of the eye. Increased oxidative stress has been considered the central factor in damaging neural retina in diabetes. Flavonoids, being powerful antioxidants, play protective roles in several oxidative stress-mediated neurodegenerative diseases. In this study, we analyzed the neuroprotective effects of a potential flavonoid, rutin, in the diabetic rat retina. Diabetes was induced in male Wistar rats by single injection of streptozotocin (65 mg/kg). In age-matched control (non-diabetic) and 1 week of diabetic rats, rutin (100 mg/kg/day) was orally administered and continued for 5 weeks. In another group of diabetic rats, only saline was supplemented. After treatments, retinas from all the groups were isolated and analyzed for potential neurotrophic factors and apoptotic and oxidative stress markers using biochemical and immunoblotting techniques. Our results indicate that rutin possesses antidiabetic activity, as blood glucose level decreased and insulin level increased in diabetic rats. In the diabetic retina, rutin supplementation enhanced the reduced levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glutathione (GSH) (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05), and reduced the level of thiobarbituric acid-reactive substances (TBARS) (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). In addition, rutin treatment showed antiapoptotic activity by decreasing the level of caspase-3 and increasing the level of Bcl-2 in the diabetic retina. These results suggest the effectiveness of rutin in ameliorating the levels of neuroprotective factors in diabetic retina. Therefore, rutin might be a potential flavonoid that can prevent the retinal damage and subsequently the development of diabetic retinopathy.

Current neuropharmacology, 2014

Diabetic retinopathy (DR) is one of the major complications of diabetes causing vision loss and b... more Diabetic retinopathy (DR) is one of the major complications of diabetes causing vision loss and blindness worldwide. DR is widely recognized as a neurodegenerative disease as evidenced from early changes at cellular and molecular levels in the neuronal component of the diabetic retina, which is further supported by various retinal functional tests indicating functional deficits in the retina soon after diabetes progression. Diabetes alters the level of a number of neurodegenerative metabolites, which increases influx through several metabolic pathways which in turn induce an increase in oxidative stress and a decrease in neurotrophic factors, thereby damage retinal neurons. Loss of neurons may implicate in vascular pathology, a clinical signs of DR observed at later stages of the disease. Here, we discuss diabetes-induced potential metabolites known to be detrimental to neuronal damage and their mechanism of action. In addition, we highlight important neurotrophic factors, whose lev...

Experimental and Therapeutic Medicine, 2015

Farooqui/Diet and Exercise in Cognitive Function and Neurological Diseases, 2015

International Journal of Molecular Sciences, 2013

Desalination and Water Treatment, 2014

ABSTRACT

Acta Ophthalmologica, 2013

To determine the expression of the endogenous anti-angiogenic and pro-fibrotic matricellular prot... more To determine the expression of the endogenous anti-angiogenic and pro-fibrotic matricellular protein thrombospondin (TSP)-2 and its receptors CD36 and CD47 in proliferative diabetic retinopathy (PDR). In addition, we examined the expression of TSP-2 in the retinas of diabetic rats. Epiretinal membranes from 14 patients with PDR and nine patients with proliferative vitreoretinopathy were studied by immunohistochemistry. Vitreous samples from 30 PDR and 25 nondiabetic patients were studied by enzyme-linked immunosorbent assay. Vitreous samples and retinas of rats were examined by Western blotting. In epiretinal membranes, vascular endothelial cells and myofibroblasts expressed TSP-2, CD36 and CD47. In PDR membranes, significant correlations were observed between numbers of blood vessels expressing the panendothelial cell marker CD34 and numbers of blood vessels and stromal cells expressing TSP-2, CD36 and CD47. The numbers of blood vessels and stromal cells expressing CD34, TSP-2, CD36 and CD47 were significantly higher in membranes with active neovascularization when compared with those with quiescent disease. Thrombospondin-2 levels in vitreous samples from PDR patients were significantly higher than those in control patients without diabetes (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Western blot analysis revealed a significant increase in the expression of intact and cleaved TSP-2 in vitreous samples from PDR patients and in the retinas of diabetic rats compared to nondiabetic controls. Upregulation of TSP-2 may be a protective mechanism against inflammation and angiogenesis associated with PDR.

Neurochemical research, 2013

Neurodegeneration is an early event in the diabetic retina which may lead to diabetic retinopathy... more Neurodegeneration is an early event in the diabetic retina which may lead to diabetic retinopathy. One of the potential pathways in damaging retinal neurons is the activation of renin angiotensin system including angiotensin II type 1 receptor (AT1R) in the diabetic retina. The purpose of this study was to determine the effect of telmisartan, an AT1R blocker on retinal level of brain derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF) and tyrosine hydroxylase (TH), glutathione (GSH) and caspase activity in the diabetic rats. The dysregulated levels of these factors are known to cause neurodegeneration in diabetic retina. Three weeks streptozotocin induced diabetic rats were orally treated or untreated with telmisartan (10 mg/kg/day). After 4 weeks of treatments, the levels of BDNF and GSH were found to be increased systemically in the sera as well as in the retina of diabetic rats compared to untreated rats as measured by enzyme-linked immunosorbent assay and biochemical techniques (p < 0.05). The caspase-3 activity in the telmisartan treated diabetic retina was decreased compared to untreated diabetic rats (p < 0.05). Western blotting experiments showed the expression levels of BDNF, CNTF and TH were increased compared to untreated diabetic rats (p < 0.05). Thus, our findings show a beneficial effect of AT1R blocker telmisartan in efficiently increasing neurotrophic support, endogenous antioxidant GSH content, and decreasing signs of apoptosis in diabetic retina.

International journal of clinical and experimental medicine, 2013

Endocrine research, 2014

Recently, American Diabetic Association has recommended glycated hemoglobin (HbA1c ≥6.5%) as an a... more Recently, American Diabetic Association has recommended glycated hemoglobin (HbA1c ≥6.5%) as an alternate to fasting plasma glucose (FPG ≥7.0 mmol/L) for diagnosis of diabetes. However, studies from different groups showed inconsistent results with the use of HbA1c criteria. We examined the validity of HbA1c cut-point of 6.5% for diagnosis of diabetes. A total of 12 785 male diabetic patients (FGP ≥7.0 mmol/L), aged 56.27 ± 13.32 years were included. The average values of FPG and HbA1c of all the 12 785 patients were 10.127 ± 0.026 mmol/L and 8.729 ± 0.013%, respectively. Sub-grouping of patients into different age categories showed significantly high levels of FPG (10.934 ± 0.123 mmol/L) in the youngest group (age, ≥20-35 years) as compared to FPG (ranged from 10.021 ± 0.052 to 10.190 ± 0.050 mmol/L) in patients with other age categories. The level of HbA1c was highest in the youngest group (8.809 ± 0.056%) and lowest in the oldest group (8.653 ± 0.082%). There was a significant correlation between FPG and HbA1c (R = 0.571, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). There were 484 patients below the diagnostic threshold (HbA1c &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;6.5%), resulting in 3.78% false negative predictions. Majority of the false negative patients were in the age group of 40-75 years and had borderline FPG (7.0-8.0 mmol/L) and HbA1c (6.0-6.5%). These findings suggest that Saudi individuals with HbA1c between 6.0% and 6.5% may be considered as &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;probable diabetic&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and their status should be verified by combined FPG and HbA1c criteria.

BMC complementary and alternative medicine, 2014