Abdul Wadood

Anti-Alzheimer’s Studies on β-Sitosterol Isolated from Polygonum hydropiper L.

The family Polygonaceae is known for its traditional use in the management of various neurological disorders including Alzheimer’s disease (AD). In search of new anti-AD drugs, β-sitosterol isolated from Polygonum hydropiper was subjected to in vitro, in vivo, behavioral and molecular docking studies to confirm its possibility as a potential anti-Alzheimer’s agent. The in vitro AChE, BChE inhibitory potentials of β-sitosterol were investigated following Ellman’s assay. The antioxidant activity was tested using DPPH, ABTS and H2O2 assays. Behavioral studies were performed on a sub-strain of transgenic mice using shallow water maze (SWM), Y-maze and balance beam tests. β-sitosterol was tested for in vivo inhibitory potentials against cholinesterase’s and free radicals in the frontal cortex (FC) and hippocampus (HC). The molecular docking study was performed to predict the binding mode of β-sitosterol in the active sites of AChE and BChE as inhibitor. Considerable in vitro and in vivo cholinesterase inhibitory effects were observed in the β-sitosterol treated groups. β-sitosterol exhibited an IC50 value of 55 and 50 μg/ml against AChE and BChE respectively. Whereas, the activity of these enzymes were significantly low in FC and HC homogenates of transgenic animals. Molecular docking studies also support the binding of β-sitosterol with the target enzyme and further support the in vitro and in vivo results. In the antioxidant assays, the IC50 values were observed as 140, 120, and 280 μg/ml in the DPPH, ABTS and H2O2 assays respectively. The free radicals load in the brain tissues was significantly declined in the β-sitosterol treated animals as compared to the transgenic-saline treated groups. In the memory assessment and coordination tasks including SWM, Y-maze and balance beam tests, β-sitosterol treated transgenic animals showed gradual improvement in working memory, spontaneous alternation behavior and motor coordination. These results conclude that β-sitosterol is a potential compound for the management of memory deficit disorders like AD.

A method optimization study for atomic absorption spectrophotometric determination of total zinc in insulin using direct aspiration technique

Abstract A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring the absorbance at 213.9 nm for determination of total zinc. System suitability parameters were evaluated and were found to be within the limits. Linearity was evaluated through graphical representation of concentration versus absorbance. Repeatability (intra-day) and intermediate precision (inter-day) were assessed by analyzing working standard solutions. Accuracy and robustness were experimented from the standard procedures. The percentage recovery of zinc was found to be 99.8%, relative standard deviation RSD 1.13%, linearity of determination LOD 0.0032 μg/mL, and limit of quantization LOQ 0.0120 μg/mL. This developed and proposed method was then validated in terms of accuracy, precision, linearity and robustness which can be successfully used for the quantization of zinc in insulin.

Conventional Versus Microwave Assisted Synthesis, Molecular DockingStudies and In Vitro Evaluation of Benzohydrazide Derivatives as NewAcetylcholinesterase and Butyrylcholinesterase Inhibitors

In the course of studies directed towards the synthesis of novel AChE and BChE inhibitors, for the treatment of Alzheimer disease, we focused on the conventional versus microwave assisted synthesis of seventeen benzohydrazide derivatives and tested their ability as AChE and BChE inhibitors. These derivatives were characterized by FT-IR, 1H-NMR, 13C-NMR and EI-MS. Seventeen derivatives exhibited varied acetylcholinesterase inhibition with IC50 values ranging between 72.04 ± 1.12 to 1320.65 ± 0.95 μM as well as butyrylcholinesterase activity with IC50 values ranging between 3.04 ± 1.48-1876.17 ± 0.95 μM as compared with standard eserine (IC50=0.85 ± 0.0001 μM). Only two analogs 3k and 3o exhibited moderate acetylcholinesterase inhibitor potential with IC50 values 72.04 ± 1.12 and 94.06 ± 1.17 μM respectively. Five analogs 3d, 3h, 3q, 3o and 3l exhibited good potent butyrylcholinesterase inhibitory potential with IC50 values 3.04 ± 1.48, 9.01 ± 0.58, 15.12 ± 0.66, 45.00 ± 0.99 and 50.19 ± 0.62 μM respectively. Molecular docking studies were carried out in order to find out the binding affinity of benzohydrazide derivatives with the enzyme.