Molecular mechanisms of the antiglycative and cardioprotective activities of Psidium guajava leaves in the rat diabetic myocardium.

Context: Antiglycative potential of Psidium guajava L. (Myrtaceae) leaves has been established. However, the molecular basis of its antiglycative potential remains unknown.

Effect of ursolic acid on cardiac marker enzymes, lipid profile and macroscopic enzyme mapping assay in isoproterenol-induced myocardial ischemic rats.

This study investigates the antihyperlipidemic effect of ursolic acid (UA) on isoproterenol (ISO) induced male albino Wistar rats. Myocardial ischemia was induced by subcutaneous injection of ISO (85 mg/kg BW) twice at an interval of 24 h, for two consecutive days. A significant increase in the activities of the serum marker enzymes [creatine kinase, creatine kinase-MB and lactate dehydrogenease (LDH)], a prominent expression of LDH 1 and LDH 2 isoenzymes, increased levels of plasma total cholesterol (TC), low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol, triglycerides (TG), free fatty acids (FFA), phospholipids (PL) and atherogenic index and decreased level of high density lipoprotein-cholesterol were observed in ISO-induced rats.

Rat sperm immobilisation effects of a protein from Ricinus communis (Linn.): an in vitro comparative study with nonoxynol-9.

Previous study conducted in our department showed that 50% ethanolic extract of the root of Ricinus communis possess reversible antifertility effect and a 62-kDa protein (Rp) from this extract is responsible for the antifertility effects. In this study, we compared the spermicidal effect of this Rp with nonoxynol-9 (N-9) in vitro. The sperm immobilisation studies showed that 100 μg ml(-1) of Rp was able to immobilise the sperms completely within 30 s.

Effect of ursolic acid treatment on apoptosis and DNA damage in isoproterenol-induced myocardial infarction.

The present study was designed to evaluate the protective effect of ursolic acid (UA) against isoproterenol-induced myocardial infarction. Myocardial infarction was induced by subcutaneous injection of isoproterenol hydrochloride (ISO) (85 mg/kg BW), for two consecutive days. ISO-induced rats showed elevated levels of cardiac troponins T (cTn T) and I (cTn I) and increased activity of creatine kinase-MB (CK-MB) in serum.

Beneficial effects of Psidium guajava leaf extract on diabetic myocardium.

Non enzymatic glycosylation (glycation) between reducing sugar and protein results in the formation of advanced glycation end products (AGEs), which is believed to play an important role in diabetes associated cardiovascular complications. Thus agents that inhibit the formation of AGEs are believed to have therapeutic potential against diabetic complications. In the present study we evaluated the antiglycative potential of ethyl acetate fraction of Psidium guajava leaves (PGEt) by administering the extract into streptozotocin induced diabetic rats.

Spermicidal action of a protein isolated from ethanolic root extracts of Achyranthes aspera: an in vitro study.

A previous study conducted in our department, showed that 50% ethanolic extract of the roots of Achyranthes aspera possess spermatotoxic effects. Preliminary studies also revealed that the active principle may be a protein. In this study a 58 kDa Achyranthes protein (Ap) was isolated from Achyranthes aspera using standard protocols and their effects on the rat sperm was studied in vitro in comparison with nonoxynol-9 (N-9).

Effects on spermatogenesis in swiss mice of a protein isolated from the roots of Ricinus communis (Linn.) (Euphorbiaceae).

This study was aimed to evaluate the effect on spermatogenesis of a 62 kDa protein (Rp) isolated from 50% ethanolic extract of the root of Ricinus communis in mice. A dose response study in mice revealed that 25mg/kg body weight/day was the most effective dose. Swiss strain mature male mice of 30 days old were divided into two group namely control and Rp treated (25mg/kg body weight/day).

Role of cardiac isoform of alpha-2 macroglobulin in diabetic myocardium.

Earlier studies from one of the investigator's laboratory have demonstrated the presence of a high molecular weight protein (182 kDa) in the blood serum of laboratory animals subjected to pressure-induced cardiac hypertrophy and suggested that this protein may be involved in the development of cardiac hypertrophy. Studies have shown that this protein is also involved in earlier stages of cardiac complications associated with diabetes, but the role of this protein in diabetic heart is less understood. So we aimed to check whether this protein is having any protective role in diabetic heart.

Antioxidant and antiglycative potential of ethyl acetate fraction of Psidium guajava leaf extract in streptozotocin-induced diabetic rats.

Hyperglycemia causes increased protein glycation and the formation of early glycation products and advanced glycation end products (AGEs) which are major factors responsible for the complications associated with diabetes. The aim of the present study was to investigate the antioxidant as well as antiglycative potential of ethyl acetate fraction of guava leaves. Oral administration of the extract at different doses showed a significant decrease in blood glucose level.

Spermatotoxicity of a protein isolated from the root of Achyranthes aspera: a comparative study with gossypol.

Background: A previous study showed that 50% ethanolic extracts of the roots of Achyranthes aspera possess spermatotoxic effects.

Study Design: A 58-kDa protein (Ap) was isolated, and its spermatotoxic effects were studied in comparison with gossypol. Ap (25 mg/kg body weight a day) and gossypol (40 mg/kg body weight a day) were administered orally to Swiss male albino mice for 35 days.

Evaluation of the cardiac isoform of alpha2-macroglobulin as a factor inducing cardiac hypertrophy.

Earlier studies from our laboratory showed that a 182-kDa high-molecular-weight protein appeared during early stages of development of cardiac hypertrophy in animals subjected to aortic constriction. Later it was confirmed that this protein is a cardiac isoform of alpha2-macroglobulin belonging to the macroglobulin family. Furthermore, it has been demonstrated that direct injection of the purified 182-kDa protein intravenously (through the tail vein) into the normal animals led to the development of cardiac hypertrophy.

Delineation of sequences essential for specific promoter activation during pressure overloaded hypertrophy or factor-induced hypertrophy.

Earlier studies from our laboratory have demonstrated the appearance of a high Mr (182-kDa) phosphoprotein during early stages of development of cardiac hypertrophy in the sera of animals subjected to aortic constriction. Furthermore, it has been reported that the injection of purified 182-kDa protein into normal animals led to the development of hypertrophy, and the injection of polyclonal antibodies into the aorta constricted animals completely, abolished the development of hypertrophy, and downregulated the expression of the beta-Myosin heavy chain (MHC) gene. To identify the cis-acting regulatory element(s), which controls induction of the beta-MHC gene in acute pressure-overloaded cardiac hypertrophy induced by the 182-kDa protein, the beta-MHC promoter fragments of various lengths linked to the chloramphenicol acetyl transferase (CAT) reporter were injected into the left ventricular apex of adult rats, which underwent aortic constriction/182-kDa protein injection or were sham-operated.

Toxicity of PCB 1232 on mitochondria of fish Arius caelatus (Valenciennes).

Mitochondrial proteins and phospholipids were estimated and SDH, Na(+)-K(+)-ATPase and Mg(2+)-ATPase activities were analysed in the gill, liver and heart tissues of PCB 1232 (sublethal doses) treated fish A. caelatus. Protein and phospholipids were found to be decreased significantly and SDH, Na(+)-K(+)-ATPase, Mg(2+)-ATPase and other enzyme systems displayed an inverse relationship with PCB dosage.

Photodynamic effects of two hydroxyanthraquinones.

The aim of this work was to investigate the photodynamic action of electron-rich anthraquinones, viz., cynodontin (CYN) and cynodontin-5,8-dimethylether (CYNM). Both optical and EPR methods are used to detect the generation of singlet oxygen.

Novel deletions in MYH7 and MYBPC3 identified in Indian families with familial hypertrophic cardiomyopathy.

Mutations causing familial hypertrophic cardiomyopathy (HCM) have been described in at least 11 genes encoding cardiac sarcomeric proteins. In this study, three previously unknown deletions have been identified in the human cardiac genes coding for beta-myosin heavy chain (MYH7 on chromosome 14) and myosin-binding protein-C (MYBPC3 on chromosome 11). In family MM, a 3-bp deletion in MYH7 was detected to be associated with loss of glutamic acid in position 927 (DeltaE927) of the myosin rod.

Direct injection and expression in vivo of full-length cDNA of the cardiac isoform of alpha-2 macroglobulin induces cardiac hypertrophy in the rat heart.

Earlier studies from this laboratory have shown that the serum protein of molecular weight of 182 kDa, which plays an indispensable role in the development of cardiac hypertrophy, may be a cardiac isoform of alpha-2 macroglobulin belonging to macroglobulin family (36). Furthermore, reports on the stable expression in vivo of several reporter genes injected directly into the myocardium of rat and the approach of direct gene transfer into adult mammalian heart to characterize the activity of a cellular gene and to modulate overall cardiac function in vivo prompted us to evaluate the hypertrophy inducing potential of a full-length cDNA for the 182 kDa protein upon direct injection. The full-length cDNA of the cardiac isoform of alpha-2 M obtained from hypertrophied rat heart mRNA and cloned in an eukaryotic expression vector namely pcDNA 3.

Cardiac isoform of alpha-2 macroglobin, a novel serum protein, may induce cardiac hypertrophy in rats.

Earlier studies from this laboratory have identified a novel high molecular weight (182 kDa) serum protein suggested to be involved in the development of cardiac hypertrophy. In the present case the role of this novel serum protein in the development of pressure-induced cardiac hypertrophy and the molecular events associated with it in experimental rats has been investigated. Multiple injections of this purified protein intravenously (through tail vein) into the normal animals lead to the development of cardiac hypertrophy and this is accompanied by an induction of muscle specific genes such as that of MLC2 and beta-MHC characteristic of pressure overloaded heart.

A novel serum protein of molecular weight 182 kDa: a molecular marker for an early detection of increased left ventricular mass in patients with cardiac hypertrophy.

Background: Earlier studies in our laboratory have shown the presence of a cardiac-hypertrophy-specific high-molecular-weight protein of 182 kDa in the sera of laboratory rats which were subjected to aortic stenosis. On the basis of a number of criteria, these studies have pointed out that this protein may be a molecular signal of hypertrophic growth in the aorta-constricted animals. Further, a similar high-molecular-weight protein has been observed in the sera of normal humans and patients with cardiac anomalies.

Epidemiology of gastro-intestinal nematodes of sheep in wet tropical conditions in Malaysia.

A study on the seasonal variations in the population structure of Haemonchus contortus and Trichostronglyus colubriformis was conducted for a period of 12 months in a typical large scale sheep farm on improved pasture in Peninsular Malaysia which has a wet tropical climate. Successive groups of helminth-free tracer lambs were grazed for 4 weeks together with naturally infected sheep and were necropised for worm counts 2 weeks after their removal from the pasture. The monthly populations of H.

Expression of proto-oncogenes, genes for muscle specific isoforms and heat shock protein (HSP) -70 gene in hypertrophied cardiac muscles from patients with atrial septal defect or tetralogy of Fallot.

Studies on the expression of proto-oncogenes and muscle specific genes in hypertrophied human hearts have shown that proto-oncogenes such as c-myc, c-fos and c-ras are activated in both atrial and ventricular tissues of patients with atrial septal defect (ASD) and tetralogy of Fallot (TOF). Although the expression of muscle specific genes such as MLC2 and skeletal alpha-actin are induced the expression of tissue specific cardiac actin remained the same in both the control and diseased tissues. Further, an increased synthesis of messengers of heat shock protein gene-HSP70 was observed in the ventricular tissues of TOF patients, with out much of a change in atrial tissues of patients with ASD.

Serum protein of 135-kDa molecular weight--a molecular signal for cardiac hypertrophy.

A serum protein, similar to the 135-kDa protein which appears during experimentally induced cardiac hypertrophy in rats, was identified in human serum by Western blot analysis using anti-rat 135-kDa protein antibody. The rat protein antibody gave a very strong positive signal when reacted with sera obtained from cardiac patients, suggesting an induced level of this protein in patients' sera when compared to normal sera from healthy individuals. Multiple injections of polyclonal anti-rat 135-kDa protein antibody to aorta-constricted animals completely inhibited the development of cardiac hypertrophy, suggesting that this protein could be hypertrophy specific.

Effect of cytosol on the regulation of expression of myosin heavy chain genes during cardiac hypertrophy.

In vitro translation of RNA transported from the rat heart nuclei has suggested that the transport of translatable messages from hypertrophic heart nuclei is greater than from sham-operated heart nuclei. An increased translation activity was observed in cell-free system with RNA transported from sham-operated heart nuclei in presence of hypertrophic heart cytosol, than from sham-operated heart cytosol. Similar results were obtained when myosin heavy chain (MHC) mRNA in the transported RNA was analyzed by slot-blot hybridization using beta cDNA probe.