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Aim: Aminoguanidine (AG), a well known inhibitor of advanced glycation end products, has been reported to attenuate cardiac hypertrophy and fibrosis. However, the underlying mechanism by which AG exerts its anti-fibrotic activity is not well understood. Reactive oxygen species (ROS) and matrix metalloproteinases (MMPs) are implicated as playing a major role in the development of cardiac fibrosis. Hence, the present study was designed to investigate the effect of AG on ROS generation and MMPs during the progress of hypertrophic growth., Main Methods: Isoproterenol (ISO) (7 mg/kg/day, s.c., for 15 days) was used to induce cardiac hypertrophy in experimental adult Wistar rats. ISO-treated rats were co-treated with AG (50 mg/kg/day, i.p., for 15 days). Ventricular collagen deposition, gelatinase activity of MMP-2 and MMP-9, and the level of tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) were investigated. In addition, in silico docking of MMP-2 and MMP-9 proteins, ROS generation, and nuclear translocation of NF-κB-p65 were also studied., Key Findings: AG co-treatment markedly attenuated the ISO-induced hypertrophic growth and fibrosis. Heart-weight-to-body weight ratio and ventricular collagen levels were normalized upon AG co-treatment. A significantly decreased level of ventricular ROS generation (p < 0.001) and NF-κB-p65 nuclear translocation was observed in the rat hearts co-treated with AG. Furthermore, in silico docking analysis revealed that AG interacts at the active site of MMP-2 and MMP-9., Significance: Anti-fibrotic and anti-hypertrophic activities of AG were mainly attributed to its ROS quenching efficacy and its direct interaction with MMP-2 and MMP-9.

Advanced glycation end products (AGEs) play a major role in the development of cardiovascular disorders in diabetic patients. Recent studies evidenced the beneficial role of phytochemicals in reducing the risk of cardiovascular diseases. Hence the present study was framed to investigate the protective role of Gallic acid (GA) on AGEs induced cardiac fibrosis. Rats were infused with in vitro prepared AGEs (50mg/kg BW-intravenous injection) for 30 days. Further, GA (25mg/kgBW) was administered to rats along with AGEs. On infusion of AGEs, induction of fibrotic markers, collagen deposition, oxidative marker NADPH oxidase (NOX-p47 phox subunit), AGE receptor (RAGE) and cytokines expression was evaluated in the heart tissues using RT-PCR, Western blot and immunostaining methods. AGEs infusion significantly (P<0.01) increased the HW/BW ratio and fibrosis (4-fold) with increased expression of matrix genes MMP-2 and -9 (P<0.01, respectively) in the heart tissues. Whereas, administration of GA along with AGEs infusion prevented the fibrosis induced by AGEs. Further, GA treatment effectively prevented the AGEs mediated up-regulation of pro-fibrotic genes and ECM proteins such as TNF-α, TGF-β, MMP-2 and -9 expression. In addition, the increased expression of NOX (P<0.01), RAGE (P<0.01), NF-κB (P<0.01) and ERK 1/2 on AGEs infusion were normalized by GA treatment. Thus the present study shows the protective effect of GA on the fibrotic response and cardiac remodeling process induced by advanced glycation end products from external sources., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

A series of biodegradable low molecular weight PLGA-PEG-PLGA tri-block copolymers have been synthesized in powder form. The anti-tuberculosis drug Isoniazid (INH) loaded polymeric core-shell nanoparticles (CSNPs) have been prepared by sonication followed by water-in-oil-in-water (w/o/w) double emulsification technique. The nanoparticles (NPs) have been characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD) and X-ray photo electron spectroscopic (XPS) techniques. The drug loaded CSNPs were found to be 150-400 nm in size with spherical shape. The drug loading efficiency and drug content of the polymer NPs were determined by UV-vis spectrophotometry. The drug loading efficiency and drug content of the NPs were (12.8-18.67%) and (6.4-8.9%) respectively. The in vitro release behavior of the polymer NPs has been investigated by UV-vis spectrophotometry and the release kinetics mechanism has been evaluated by Korsemeyer-Peppas (KP) and Higuchi models. The in vitro release studies show initial burst release followed by controlled and uniform release for longer duration. The pharmacokinetic studies show that the INH bioavailability of INH loaded CSNPs is 28 fold higher than that of free INH and also the CSNPs show sustained drug release for longer duration., (Copyright © 2013 Elsevier B.V. All rights reserved.)