Naiyer Shahzad

Evidence of Trem2 Variant Associated with Triple Risk of Alzheimer’s Disease

Alzheimer’s disease is one of the main causes of dementia among elderly individuals and leads to the neurodegeneration of different areas of the brain, resulting in memory impairments and loss of cognitive functions. Recently, a rare variant that is associated with 3-fold higher risk of Alzheimer’s disease onset has been found. The rare variant discovered is a missense mutation in the loop region of exon 2 of Trem2 (rs75932628-T, Arg47His). The aim of this study was to investigate the evidence for potential structural and functional significance of Trem2 gene variant (Arg47His) through molecular dynamics simulations. Our results showed the alteration caused due to the variant in TREM2 protein has significant effect on the ligand binding affinity as well as structural configuration. Based on molecular dynamics (MD) simulation under salvation, the results confirmed that native form of the variant (Arg47His) might be responsible for improved compactness, hence thereby improved protein folding. Protein simulation was carried out at different temperatures. At 300K, the deviation of the theoretical model of TREM2 protein increased from 2.0 Å at 10 ns. In contrast, the deviation of the Arg47His mutation was maintained at 1.2 Å until the end of the simulation (t = 10 ns), which indicated that Arg47His had reached its folded state. The mutant residue was a highly conserved region and was similar to “immunoglobulin V-set” and “immunoglobulin-like folds”. Taken together, the result from this study provides a biophysical insight on how the studied variant could contribute to the genetic susceptibility to Alzheimer’s disease.

Phytosterols as a natural anticancer agent: Current status and future perspective

Phytosterols are naturally occurring compounds in plants, structurally similar to cholesterol. The human diet is quite abundant in sitosterol and campesterol. Phytosterols are known to have various bioactive properties including reducing intestinal cholesterol absorption which alleviates blood LDL-cholesterol and cardiovascular problems. It is indicated that phytosterol rich diets may reduce cancer risk by 20%. Phytosterols may also affect host systems, enabling antitumor responses by improving immune response recognition of cancer, affecting the hormone dependent endocrine tumor growth, and by sterol biosynthesis modulation. Moreover, phytosterols have also exhibited properties that directly inhibit tumor growth, including reduced cell cycle progression, apoptosis induction, and tumor metastasis inhibition. The objective of this review is to summarize the current knowledge on occurrences, chemistry, pharmacokinetics and potential anticancer properties of phytosterols in vitro and in vivo. In conclusion, anticancer effects of phytosterols have strongly been suggested and support their dietary inclusion to prevent and treat cancers.

Interactions of atenolol with alprazolam/escitalopram on anxiety, depression and oxidative stress

Anxiety and depression are highly comorbid disorders possibly sharing a common neurobiological mechanism. The dysfunction of serotoninergic, noradrenergic and dopaminergic neurotransmission, abnormal regulation in the hypothalamic-pituitary-adrenal axis (HPA), disturbance of cellular plasticity including reduced neurogenesis, or chronic inflammation connected with high oxidative damage play a crucial role in the development of anxiety and depression. The present study was aimed to investigate the effects of atenolol alone and in combination with alprazolam/escitalopram on anxiety, depression and oxidative stress. Wistar albino rats were subjected to 21 day treatment of drugs then exposed to elevated-plus maze (EPM) and modified forced swim test (MFST), and oxidative stress markers were estimated in isolated brain tissue of all groups. The results indicated that atenolol in combination with alprazolam/escitalopram exhibited antidepressant effects by significantly decreasing the immobility and increasing the swimming behavior in the MFST and anti-anxiety effects by increasing the percentage preference and number of open arm entries as well as time spent in open arm in EPM. Pretreatment with atenolol alone and combination with alprazolam/escitalopram also ameliorated tissue glutathione (GSH) and decreased malondialdehyde (MDA) level significantly which explore antioxidant properties of drugs, and combination augments the therapeutic response of monotherapy in depression. In conclusion behavioral and biological findings indicate that the combination of atenolol with alprazolam/escitalopram has the potential of being highly efficacious in treating anxiety and depressive disorders as well as oxidative stress.

The gastroprotective effects of hydroalcoholic extract of Monolluma quadrangula against ethanol-induced gastric mucosal injuries in Sprague Dawley rats

Monolluma quadrangula (Forssk.) Plowes is used in Saudi traditional medicines to treat gastric ulcers. The hydroalcoholic extract of M. quadrangula (MHAE) was used in an in vivo model to investigate its gastroprotective effects against ethanol-induced acute gastric lesions in rats. Five groups of Sprague Dawley rats were used. The first group was treated with 10% Tween 20 as a control. The other four groups included rats treated with absolute ethanol (5 mL/kg) to induce an ulcer, rats treated with 20 mg/kg omeprazole as a reference drug, and rats treated with 150 or 300 mg/kg MHAE. One hour later, the rats were administered absolute ethanol (5 mL/kg) orally. Animals fed with MHAE exhibited a significantly increased pH, gastric wall mucus, and flattening of the gastric mucosa, as well as a decreased area of gastric mucosal damage. Histology confirmed the results; extensive destruction of the gastric mucosa was observed in the ulcer control group, and the lesions penetrated deep into the gastric mucosa with leukocyte infiltration of the submucosal layer and edema. However, gastric protection was observed in the rats pre-fed with plant extracts. Periodic acid–Schiff staining of the gastric wall revealed a remarkably intensive uptake of magenta color in the experimental rats pretreated with MHAE compared to the ulcer control group. Immunohistochemistry staining revealed an upregulation of the Hsp70 protein and a downregulation of the Bax protein in rats pretreated with MHAE compared with the control rats. Gastric homogenate showed significantly increased catalase and superoxide dismutase, and the level of malondialdehyde (MDA) was reduced in the rats pretreated with MHAE compared to the control group. In conclusion, MHAE exhibited a gastroprotective effect against ethanol-induced gastric mucosal injury in rats. The mechanism of this gastroprotection included an increase in pH and gastric wall mucus, an increase in endogenous enzymes, and a decrease in the level of MDA. Furthermore, protection was given through the upregulation of Hsp70 and the downregulation of Bax proteins.

Renal protective effect of SGLT2 inhibitor dapagliflozin alone and in combination with irbesartan in a rat model of diabetic nephropathy

Considering the complementary mechanisms of SGLT2 inhibitors and angiotensin inhibitors on kidney, it is postulated that combination of both agents could afford greater protection against diabetic renal injury. So, we investigated renal protective effects of SGLT2 inhibitor, dapagliflozin, alone and in combination with irbesartan in a rat model of diabetic nephropathy. Diabetic rats, injected with nicotinamide-streptozotocin, were treated orally for 12 weeks with either vehicle, dapagliflozin 2 mg/kg/day, irbesartan 30 mg/kg/day, or combination of both drugs; respectively. Biochemical analysis included blood glucose, HbA1c, urinary albumin excretion, creatinine clearance, TGF-β1, sRAGE, oxidative markers, and histopathological examination of kidneys. Treatment with dapagliflozin, irbesartan, and especially their combination, produced significant reduction in albuminuria, improved renal function parameters, increased sRAGE level and improved inflammatory and oxidative markers, together with amelioration of renal histopathological changes. Beside glycemic control, dapagliflozin produced higher sRAGE levels than irbesartan, suggesting that inhibition of AGE-RAGE axis is important in its renoprotective action. Combination of dapagliflozin and irbesartan produced more remarkable protective effects on renal function and structure, than use of either agent alone. It is concluded that, combination of SGLT2 inhibitor, dapagliflozin and ARB, irbesartan could offer more effective renal protection and represent a promising therapeutic option for management of diabetic nephropathy.

The effect of some immunomodulatory and anti-inflammatory drugs on Li-pilocarpine-induced epileptic disorders in Wistar rats

Evidence shows that inflammatory and immune processes within the brain might account for the pathophysiology of epilepsy. Therefore, developing new antiepileptic drugs that can modulate seizures through mechanisms other than traditional drugs is required for the treatment of refractory epilepsy. This study aims to determine the relationship between brain inflammation and epilepsy, to examine the contribution of some biochemical parameters involved in brain inflammation, and to address the effect of pharmacological interventions using some anti-inflammatory and immunomodulatory drugs in an experimental epilepsy model. Adult male rats were divided into seven groups of 20. G1 was the normal, non-treated control. G2 was the epileptic, non-treated group. G3-G7 were treated with celecoxib, methotrexate, azathioprine, dexamethasone, and valproate, respectively, for a period of three weeks. Induction of status epilepticus (SE) by Li-pilocarpine was performed on groups G2-G7. EEG tracing was conducted, and inflammatory mediators (brain and serum IL-1ß, IL 6, PGE2, HSP70, TGF-β2, and IFNγ) were measured. The induction of SE increased the amplitude and frequency of EEG tracing and inflammatory mediators more than in the normal control group. Treatments of epileptic rats reduced the frequency and amplitude of EEG tracing and significantly decreased the levels of inflammatory mediators in some treated rats compared to G2. These findings demonstrate that some anti-inflammatory and immunomodulatory drugs can lower the frequency and amplitude of seizures and reduce some inflammatory mediators in epilepsy treatments, strengthening the possibility that targeting these immunological and inflammatory pathways may represent another effective therapeutic approach to preventing epileptic seizures.

Resveratrol-loaded PLGA nanoparticles mediated programmed cell death in prostate cancer cells

Resveratrol (RL), a natural polyphenol, is known for its diverse biological effects against various human cancer cell lines. But low aqueous solubility, poor bioavailability, and stability limit its efficacy against prostate cancer. In this study polymeric nanoparticles encapsulating resveratrol (RLPLGA) were designed and their cytotoxic and mode of apoptotic cells death against prostate cancer cell line (LNCaP) was determined. Nanoparticles were prepared by solvent displacement method and characterized for particle size, TEM, entrapment efficiency, DSC and drug release study. RLPLGA exhibited a significant decrease in cell viability with 50% and 90% inhibitory concentration (IC50 and IC90) of 15.6 ± 1.49 and 41.1 ± 2.19 μM respectively against the LNCaP cells. This effect was mediated by apoptosis as confirmed by cell cycle arrest at G1-S transition phase, externalization of phosphatidylserine, DNA nicking, loss of mitochondrial membrane potential and reactive oxygen species generation in LNCaP cells. Furthermore, significantly greater cytotoxicity to LNCaP cells was observed with nanoparticles as compared to that of free RL at all tested concentrations. RLPLGA nanoparticles presented no adverse cytotoxic effects on murine macrophages even at 200 μM. Our findings support the potential use of developed resveratrol loaded nanoparticle for the prostate cancer chemoprevention/ chemotherapy with no adverse effect on normal cells.

Vitamin D enhances antiepileptic and cognitive effects of lamotrigine in pentylenetetrazole-kindled rats

Despite long use of antiepileptic drugs, it remains a challenge to achieve seizure control while reducing adverse effects and preventing cognitive impairment. Several lines of evidence suggest a role of vitamin D in epilepsy. So this study aimed to investigate the effect of vitamin D on epileptogenesis, cognitive dysfunction and antiepileptic activity of lamotrigine, in a rat model of chemical kindling. Rats were kindled by pentylenetetrazole injections every other day over four weeks, together with daily oral treatment by either vehicle, vitamin D, lamotrigine or combination of vitamin D and lamotrigine. The non-treated kindled rats developed generalized seizures and had poor cognitive performance in water maze, associated with prooxidative status; elevated malondialdehyde and nitric oxide with lowered glutathione levels; in brain tissues. Treatment with either vitamin D, lamotrigine or both leads to significant reduction of seizure activity score, improvement of cognitive performance, and amelioration of the disturbed oxidative stress biomarkers. These findings indicate that, vitamin D has anti-epileptic, cognitive improving and antioxidant effects, on its own and enhance the effects of lamotrigine, in a chronic model of epileptic seizures. Thus, vitamin D supplementation may be a useful addition to antiepileptic drugs improving seizure control and cognitive function in patients with epilepsy.

Therapeutic adherence: A prospective drug utilization study of oral hypoglycemic in patients with type 2 diabetes mellitus

Abstract Objective To determine the drug utilization patterns and outcomes of treatment in terms of metabolic control in the type 2 diabetic patients on oral hypoglycemic agents in the outpatient department in the teaching hospital of Hamdard University, New Delhi, India. Methods Patients with established type 2 diabetes (n=184) visiting the outpatient department were interviewed using a structured questionnaire over a period of five months. Results Majority of the type 2 diabetic patients in this setting were treated with a multiple oral hypoglycemic agents. The most commonly prescribed oral hypoglycemic agent was biguanides (metformin) followed by sulfonylureas (glimepiride), thiazolidinediones (pioglitazone), alpha-glucosidase inhibitors (miglitol) and dipeptidyl peptidase-4 inhibitors (vildagliptin). As monotherapy metformin was the most common choice followed by glimepiride and voglibose, the most prevalent multiple therapy was a three-drug combination of glimepiride + metformin + pioglitazone. The study showed poor compliance to the prescribed therapy. Conclusions This study prospected the need of patient education and counselled to enhance the patient compliance for prescribed oral hypoglycemic agents and concomitant drugs. There is need for diet control as well as blood glucose and HbA1c monitoring. Metabolic control was found to be poor in the study population. HbA1c monitoring was underutilized. Clinical monitoring of patients adherence to the prescribed treatment to achieve good glycemic control is recommended. Measures should be taken to improve patients adherence to the prescribed treatment.

In vitro and In vivo Study of Effect of α-Adrenergic Agonist-Methyldopa on the Serum Biochemical Laboratory Findings

Objectives: The effects of the antihypertensive drug methyldopa on biochemical laboratory findings were monitored both in vitro and in vivo particularly those of metabolites and enzymes which are routinely requested by physicians. Methods: In vitro and in vivo studies were performed. For the in vitro study, solutions of methyldopa concentrations were prepared according to its maximum serum concentration as reported in the literature and were added to blank, normal serum. The samples were then analyzed in parallel with a standard test using the same laboratory techniques. For the in vivo study, blood was collected before starting and two weeks after starting methyldopa therapy from 40 subjects that were newly diagnosed with essential hypertension. The control sera were collected from 30 healthy volunteers of comparable ages. The samples were analyzed for glucose, Total Protein (TP), urea, creatinine, Total Cholesterol (TC), Triglyceride (TG), Aspartate Transaminase (AST), Alanine Transaminase (ALT), Lactate Dehydrogenase (LDH) and Creatine Kinase (CK). Results: In the in vitro study, methyldopa induced a decrease in the readings of serum glucose, TP, urea, TC, AST, ALT, and CK, whereas the LDH levels recorded an increase. In vivo study of methyldopa leads to increase the levels of serum glucose, TP, urea, TC, TG, AST, ALT and LDH. Conclusions: Methyldopa induced significant alterations in the in vitro as well as in the in vivo measurements. These alterations are required to be taken seriously by physicians to avoid misinterpretations of data generated during routine practice. All the in vitro changes in biochemical parameters are a result of chemical or physical reactions, whereas the in vivo changes resulted mostly from physiological or metabolic factors.