👤 Umar Nishan

Alzheimer's disease (AD) is characterized by the gradual deterioration of cognitive functions, speech impairment, and memory loss. It can potentially be treated by targeting the beta-site amyloid precursor protein cleavage enzyme 1 (BACE1), which plays a key role in amyloid plaque formation, neurofibrillary tangles, and hyperphosphorylated tau protein. Current drugs have limitations in terms of safety, efficacy, and blood-brain barrier permeability. In view of this, this study was designed to determine the potential inhibitors of the BACE1 enzyme by virtual screening using a curated library of 415 natural products including terpenoids, phenolic compounds, and alkaloids from different medicinal plants. Based on the docking score and interaction analysis, 50 compounds were selected for the downstream analysis, such as ligand binding interactions, pharmacokinetics, druglikness and physicochemical parameters. Among the lead compounds, Palmatine (compound 45) and Berberine (compound 49), demonstrated optimal drug-likeness and blood-brain barrier permeability among the top compounds. 2-[(9Z,12Z)-heptadeca-9,12-dienyl]-6-hydroxybenzoic acid (compound 4) was inactive in most toxicity parameters. Pharmacophore analysis revealed that Palmatine and Berberine share similar features with the standard, highlighting their potential as effective compounds. Furthermore, structural chemistry analysis provided insights on their shared isoquinoline alkaloid framework, illustrating their structural similarities. Molecular dynamics simulations confirmed the stability of the Palmatine-BACE1 and Berberine-BACE1 complexes during a 50 ns production run. Overall, these findings highlighted the potential of Palmatine and Berberine as promising candidates for the experimental validation and the development of the drugs for the treatment of AD. Show less

To evaluate the diagnostic performance of APOA4, CEACAM1, CD147, DJ-1/PARK7, Gamma-synuclein, S100A1, and Stathmin-1 in urothelial carcinoma and establish optimal immunohistochemical cutoffs for their use as diagnostic markers. This cross-sectional study included 141 histologically confirmed urothelial carcinoma cases and controls. Immunohistochemical staining was optimized for each biomarker, and semiquantitative scoring was applied. Diagnostic validity was assessed using receiver operating characteristic (ROC) analysis, comparing sensitivity and specificity across several cutoffs and biomarker panels. Among seven biomarkers, APOA4, DJ-1/PARK7, Gamma-synuclein, and Stathmin-1 demonstrated high diagnostic accuracy (≥80% sensitivity and specificity). Using an Allred score ≤2 as a cutoff, the sensitivity/specificity were as follows: APOA4, 96%/100%; DJ-1/PARK7, 97%/94%; Gamma-synuclein, 98%/84%; and Stathmin-1, 98%/90%. A combined panel of these four biomarkers achieved near-perfect diagnostic performance, reaching almost 100% sensitivity and specificity. A biomarker panel comprising Stathmin-1, DJ-1/PARK7, Gamma-synuclein, and APOA4 reliably distinguished urothelial carcinoma from benign urothelium. These markers, when integrated with cytology, could enhance the diagnostic precision and reduce dependence on invasive cystoscopy. The proposed cutoffs (10%-20% positive cells or Allred score ≤2) offer clinically actionable threshold for histopathological practice. Show less

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive decline, driven by the accumulation of amyloid-beta plaques and neurofibrillary tangles. It involves the dysfunction of key enzymes such as Acetylcholinesterase (AChE) and β-secretase (BACE1), making them critical targets for therapeutic intervention. In this study we investigated an in-house library of 820 secondary metabolites obtained from Ayurvedic plants against AChE and BACE1 with the aim to discover novel leads for AD. Virtual screening resulted in 15 ligands, mostly belonging to the ursane-type or dammarene-type triterpene saponins of Centella asiatica, reestablishing the potency of this plant in drug discovery against AD. The binding affinities were further verified by molecular dynamics (MD) simulation trajectories, including root mean square fluctuations (RMSF), root mean square deviation (RMSD), hydrogen bonding analysis, Coulomb interaction calculation, Lennard-Jones interactions, and the total interaction energy. Moreover, extensive Principal Component Analysis (PCA) and Gibbs free energy landscape were performed. Our results demonstrated three compounds, namely (S)-eriodictyol 7-O-(6-β-O-trans-p-coumaroyl)-β-d-glucopyranoside, sitoindoside-X and 1,5-di-o-caffeoyl quinic acid as more effective in treating AD due to their comparable drug-like properties. Drug-likeness, structural chemistry, pharmacophore, and ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) analysis support their potential for future drug development. To establish the effectiveness of these lead compounds against AD, additional experimental testing should be performed. Show less

In the current study, we examined the antioxidant activity and anti-amyloidogenic potential of 6-aminoflavone in an adult mice model of d-galactose-induced aging. Male albino eight-week-old mice were assigned into four groups: 1. the control group (saline-treated), 2. d-galactose-treated mice (100 mg/kg/day, intravenously) for eight weeks, 3. d-galactose-treated mice (100 mg/kg/day, intravenously for eight weeks) and 6-AF-treated mice (30 mg/kg/day, intravenously for the final four weeks), and 4. 6-AF-treated mice (30 mg/kg/day i.p. for four weeks). We conducted many assays for antioxidant enzymes, including lipid peroxidation, catalase, glutathione (GSH), peroxidase (POD), and sulfoxide dismutase (SOD) (LPO). Western blotting was used to assess protein expression while the Morris water maze (MWM) and Y-maze (YM) were used to study behavior. The findings show that 6-AF greatly improved neuronal synapse and memory impairment brought on by d-galactose and it significantly inhibited BACE1 to reduce the amyloidogenic pathway of A (both amyloid β production and aggregation) by upregulating Nrf2 proteins (validated through molecular docking studies) and suppressing phosphorylated JNK and TNF-α proteins in adult albino mice's brain homogenates. These findings suggest that 6-AF, through the Nrf2/p-JNK/TNF-α signaling pathway, can diminish the oxidative stress caused by d-galactose, as well as the amyloidogenic route of A formation and memory impairment. Show less