Potential role and mechanisms of subcellular remodeling in cardiac dysfunction due to ischemic heart disease

Several studies have revealed varying degrees of changes in sarcoplasmic reticular and myofibrillar activities, protein content, gene expression and intracellular Ca-handling during cardiac dysfunction due to ischemia-reperfusion (I/R); however, relatively little is known about the sarcolemmal and mitochondrial alterations, as well as their mechanisms in the I/R hearts. Because I/R is associated with oxidative stress and intracellular Ca-overload, it has been indicated that changes in subcellular activities, protein content and gene expression due to I/R are related to both oxidative stress and Ca-overload. Intracellular Ca-overload appears to induce changes in subcellular activities, protein contents and gene expression (subcellular remodeling) by activation of proteases and phospholipases, as well as by affecting the genetic apparatus, whereas oxidative stress is considered to cause oxidation of functional groups of different subcellular proteins in addition to modifying the genetic machinery. Ischemic preconditioning, which is known to depress the development of both intracellular Ca-overload and oxidative stress due to I/R, was observed to attenuate the I/R-induced subcellular remodeling and improve cardiac performance. It is suggested that a combination therapy with antioxidants and interventions, which reduce the development of intracellular Ca-overload, may improve cardiac function by preventing or attenuating the occurrence of subcellular remodeling due to ischemic heart disease. It is proposed that defects in the activities of subcellular organelles may serve as underlying mechanisms for I/R-induced cardiac dysfunction under acute conditions, whereas subcellular remodeling due to alterations in gene expression may explain the impaired cardiac performance under chronic conditions of I/R.

Neuropharmacological profile of Eclipta alba (Linn.) Hassk

The present study deals with the investigation of standardized and phytochemically evaluated aqueous and hydroalcoholic extracts of the plant Eclipta alba for sedative, muscle-relaxant, anxiolytic, nootropic and anti-stress activities. The hydrolyzed fraction of the aqueous extract was also subjected to similar studies in rats. The aqueous and hydroalcoholic extracts were administered in a dose of 150 and 300 mg/kg, p.o., while the hydrolyzed fraction was administered in a dose of 30 mg/kg, p.o. The findings indicated nootropic activity of the aqueous extract (300 mg/kg, p.o.) and its hydrolyzed fraction (30 mg/kg, p.o.). The effect of the extracts on stress-induced alterations was evaluated. The aqueous extract and the hydrolyzed fraction provided protection against cold restraint induced gastric ulcer formation and also normalized the white blood cell count in the milk induced leukocytosis challenge model. The hydroalcoholic extract on the other hand demonstrated a significant effect only in the milk induced leukocytosis challenge model. The results point towards the potential neuropharmacological activity of the plant Eclipta alba as a nootropic and also having the property of attenuating stress induced alterations. Further neurochemical investigations can unravel the mechanism of action of the plant drug with respect to nootropic activity and help to establish the plant in the armamentarium of nootropic agents.

Effect of leaves of Butea frondosa on stress, anxiety, and cognition in rats

The plant Butea frondosa has been indicated in the Indian system of medicine as a plant augmenting memory and as a rejuvenator. The effect of oral administration of the aqueous and alcoholic extracts of the leaves was assessed on stress, cognitive function, and anxiety in albino rats. The antistress activity was evaluated using cold restraint induced ulcers and leukocyte count after subcutaneous injection of milk. The aqueous extract provides protection against stress-induced gastric lesions while both the alcoholic as well as the aqueous extract normalizes the white blood cell count. Effect on cognitive function was evaluated using Cook and Weidley's pole apparatus. The results indicate that the aqueous extract and the alcoholic extract when administered at a dose of 300 mg/kg for a period of 7 days augment both the acquisition as well as the retention of memory of learned task. The absence of an increase in the occupancy of the open arm in the elevated plus maze and in the number of head dips in the hole-board paradigms indicates that both the extracts are devoid of anxiolytic activity. Nootropic activity was compared using piracetam (100 mg/kg po) as the standard, while for anxiolytic and antistress activity, diazepam (1.0 mg/kg ip) was employed as the standard drug. It is concluded that the aqueous and alcoholic extract of B. frondosa possesses antistress and weak nootropic activity.

Carnitine palmitoyltransferase-I, a new target for the treatment of heart failure: perspectives on a shift in myocardial metabolism as a therapeutic intervention

Although the heart is capable of extracting energy from different types of substrates such as fatty acids and carbohydrates, fatty acids are the preferred fuel under physiological conditions. In view of the presence of diverse defects in myocardial metabolism in the failing heart, changes in metabolism of glucose and fatty acids are considered as viable targets for therapeutic modification in the treatment of heart failure. One of these changes involves the carnitine palmitoyltransferase (CPT) enzymes, which are required for the transfer of long chain fatty acids into the mitochondrial matrix for oxidation. Since CPT inhibitors have been shown to prevent the undesirable effects induced by mechanical overload, e.g. cardiac hypertrophy and heart failure, it was considered of interest to examine whether the inhibition of CPT enzymes represents a novel approach for the treatment of heart disease. A shift from fatty acid metabolism to glucose metabolism due to CPT-I inhibition has been reported to exert beneficial effects in both cardiac hypertrophy and heart failure. Since the inhibition of fatty acid oxidation is effective in controlling abnormalities in diabetes mellitus, CPT-I inhibitors may also prove useful in the treatment of diabetic cardiomyopathy. Accordingly, it is suggested that CPT-I may be a potential target for drug development for the therapy of heart disease in general and heart failure in particular.

Comparative effect of oral administration and topical application of alcoholic extract of Terminalia arjuna bark on incision and excision wounds in rats

The effects of 50% ethanolic extract of the bark Terminalia arjuna and tannins isolated from the bark were studied for wound healing activity in incision and excision wound models, after oral or topical application in form of a hydrogel. The findings revealed a statistically significant increase in the tensile strength of the incision wounds and increase in the percent reduction in wound size of excision wounds as compared to control. However, the topical treatment with tannins was found to be superior in both incision and excision wound studies. The estimated increase in hydroxyproline content of the granulation tissue of the excision wounds indicated rapid collagen turnover thus, leading to rapid healing of the wounds.

Hypolipidemic activity of Acorus calamus L. in rats

The rhizomes of Acorus calamus are empirically used in the treatment of a wide variety of human diseases. Administration of the 50% ethanolic extract (100 and 200 mg/kg) as well as saponins (10 mg/kg) isolated from the extract demonstrated significant hypolipidemic activity. On the contrary, the aqueous extract showed hypolipidemic activity only at a dose of 200 mg/kg.

Pathogenesis of atherosclerosis: A multifactorial process

Atherosclerosis is a leading cause of mortality and morbidity in the western world. It has been recognized for over a century, and the understanding of its pathogenesis has undergone many changes. Pathophysiological studies have unravelled the interactions of molecular and cellular elements involved in atherogenesis. The focus has shifted to the novel risk factors as well as characteristics and stability of atherosclerotic plaque; the genetic predisposition has further broadened the pathogenetic mechanisms. This review focuses on the molecular mechanisms involved in the evolution of the atherosclerotic plaque that may pave the way for selecting optimal therapies and preventing plaque complications. Atherosclerosis is no longer a disease attributed mainly to the high lipid content of the body. New insight into the disease pathology has shown it to be a disease of much greater ramifications. Endothelial damage and reactive oxygen species (and other free radicals) have predominantly emerged as factors in virtually all pathways leading to the development of atherosclerosis due to hyperlipidemia, diabetes, hypertension or smoking. Novel risk factors such as hyperhomocysteinemia, infections and systemic lupus erythematosus have emerged. Atherosclerosis has come to be regarded as a chronic inflammatory disease with an autoimmune component. The genetic basis of the disease assumes significance as candidate genes are identified and gene therapy becomes a promising new addition to the existing, less substantial conventional therapies.

Comparative evaluation of Butea frondosa and flurbiprofen for ocular anti-inflammatory activity in rabbits

The roots and leaves of the plant Butea frondosa were evaluated for ocular anti-inflammatory activity on the subacute model of ocular inflammation in rabbits. The arkas (liquid preparations obtained by distillation of certain liquids or drugs soaked in water, using the Arka-Yantra or any other convenient modern distillation apparatus) were prepared using the roots and leaves of the plant. The arkas were formulated as gels using Pluronic F-127 (PF-127) 30% w/w as the polymer. The anti-inflammatory activity of the preparations were assessed by determining their effects on elevated intraocular pressure consequent to breakdown of blood/aqueous humour barrier. A commercial eyedrop of flurbiprofen 0.03% w/w was used to compare the ocular anti-inflammatory activity of the arkas of the plant. A marketed root arka was included in the study for comparison. The anti-inflammatory activity of the arkas formulated as gels were compared with flurbiprofen gel prepared using the same polymer. The changes in intraocular pressure were monitored at various time intervals after a single dose administration of the aqueous as well as gel formulations. In multiple dose studies the aqueous preparations were administered three times a day, while the gels were administered once a day up to day 30 and the intraocular pressure was monitored on different days post-administration. The findings reveal statistically significant differences (P < 0.05) between the arkas of the plant and the commercial eyedrop of flurbiprofen. The arkas of the plant proved to be better than the eyedrop of flurbiprofen, while with respect to gels, the intraocular pressure monitored at various time intervals revealed no statistically significant difference (P > 0.05) between the gel formulations. However, the changes in intraocular pressure monitored on different days post-administration until day 30, demonstrated that the gel produced from B. frondosa leaves arka was superior to all the other gels with respect to the extent of reduction of elevated intraocular pressure elicited experimentally.