Posted by admin on Oct 1, 2014 in |
The objective of this study was to extract ursolic acid (UA) from Ocimum sanctum, to synthesize its derivatives and to examine the improvement of the antioxidative activity. Present work involved structural modification of UA at the C-3 and C-28 positions. UA derivatives, namely UA-4 and UA-7 with distinct property were synthesized. Comparative evaluation of antioxidant activity of UA, UA-4 and UA-7 using in-vitro assays and lymphocyte model system involved: (i) inhibition of liposomal lipid peroxidation by UA and its derivatives (ii) assessment of trolox equivalent antioxidative capacity (TEAC) (iii) ABTS and DPPH radicals scavenging ability and (iv) cell death (MTT assay) under hydrogen peroxide (H2O2) induced oxidative stress. A moderate increase in antioxidant activity of compound UA-4 compared to UA was observed. In contrast, significant improvement in the antioxidant activity of UA-7 was observed. To evaluate antioxidant effects on lymphocytes, we exposed cells with UA and its derivatives along with hydrogen peroxide. This was followed by measurement of cell viability by trypan blue exclusion assay and cell death using...
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Posted by admin on Oct 1, 2014 in |
Thromboembolic disorders are the leading cause of human mortality. Therefore, development of effective anticoagulant therapy is critical. Factor XIIIA (FXIIIA) protein is a crucial factor in the blood coagulation cascade, and hence, it is a vital target for the evolution of new antithrombotic agents. Structure-function studies of clotting factor active sites, clot formation, and thrombus structure have gained prominence in the efforts to develop novel anticoagulants. Factor XIIIA was homology modeled with the human transglutaminase-2 crystal structure as a base template for BLAST analysis. Docking and comparative binding site analysis revealed active site residue conservation and inhibitor-protein interactions. Nineteen small molecules possessing suspected anticoagulant properties were successfully docked into the FXIIIA active site following the best CoMFA and CoMSIA prediction values. Dabigatran etexilate was anticipated to be the best FXIIIA inhibitor among the nineteen anticoagulants with the highest binding affinity for the FXIIIA protein, and the highest FlexX docks score of -29.8 KJ/mol. Structural properties of FXIIIA inhibitors with increased antithrombotic activity were predicted by this docking...
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Posted by admin on Oct 1, 2014 in |
The present study was aimed to improve the water solubility and bioavailability of telmisartan by solid dispersion technique. Telmisartan is 4′-[(1,4′-dimethyl-2′-propyl[2,6′-bi-1H-benzimidazol]-1 ‘- yl) methyl]- [1, 1’-biphenyl]- 2- carboxylic acid. Telmisartan is practically insoluble in water. Telmisartan is an angiotensin II receptor antagonist (ARB), used in the management of hypertension. Solid dispersions of telmisartan were prepared by using polyethylene glycol 4000 and mannitol as hydrophilic carriers in different weight ratios by a solvent evaporation method. The drug and the solid dispersions were characterized by saturation solubility studies, in-vitro dissolution study, Fourier-transform infrared spectroscopy, differential scanning calorimetry, drug content estimation, and stability study. Based on physical characters and drug release pattern, formulation F2 (1 g drug, 4 g PEG 4000 and 1 g mannitol) exhibited the best results. The carriers, polyethylene glycol 4000 and mannitol, were found to be effective in increasing the aqueous solubility and dissolution rate of telmisartan in solid dispersions when compared to the pure...
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Posted by admin on Oct 1, 2014 in |
Chronotherapy involves the release of drug to the systemic circulation based on the circadian rhythm associated with the pathophysiology of a disease. Candesartan Cilexetil, an anti-hypertensive drug, is formulated to contribute to the chronotherapy of hypertension. Solubility study of the drug (BCS Class II) in various media indicated maximum solubility in pH 6.8 sodium phosphate buffer containing 1% SLS. Solid dispersion of Candesartan Cilexetil with PVP K30 was prepared by melt dispersion. Core tablet containing solid dispersion equivalent to 16mg Candesartan Cilexetil was prepared by direct compression. The % dissolution efficiency (DE60) of the pure drug was 31.05% and increased for the solid dispersion to 56%. Compression coating was applied to this core tablet by direct compression using release rate retardants HPMC K15M and Eudragit S100 in various proportions to give timed-release. In-vitro drug release test carried out in 0.1 N HCl for the first 2 h and pH 6.8 buffer containing 1% SLS for next 8 hrs showed formulation F4 containing 75 % of HPMC K15M and 25%...
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Posted by admin on Oct 1, 2014 in |
The present study investigated the antioxidant and antiproliferative efficacy of Andrographis paniculata, a well-known medicinal plant, using in-vitro systems. The dried leaves of A. paniculata were powdered and subjected to successive solvent extraction taking from polar to non-polar solvents (descending polarity) and simultaneously from non-polar to polar solvents (ascending polarity). Solvents used for extraction were hexane, chloroform, ethyl acetate, acetone, methanol, and water. All the extracts were screened for the presence or absence of various secondary metabolites. The antioxidant activity of all extracts at 100 μg/ml was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Further DPPH assay and reducing power assay were used to check the free radical scavenging capacity of methanolic and water extracts at their lower concentrations. The methanolic and water extracts of A. paniculata exhibited maximum DPPH inhibition of 20.75% and 17.71% respectively, at 100 μg/ml. A positive correlation between reducing power and concentration was found. Thin Layer Chromatography (TLC) of methanolic and water extracts of A. paniculata was performed. The antiproliferative effect of different concentrations of methanolic...
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