Rolee Sharma

Verbascoside isolated from Tectona grandis mediates gastric protection in rats via inhibiting proton pump activity

Evidences have suggested that Tectona grandis (TG) attenuates gastric mucosal injury; however its mechanism has not yet been established. The aim of present study was to evaluate the gastroprotective mechanism of ethanolic extract of TG (E-EtOH), butanolic fraction (Fr-Bu) and to identify its active constituents. Anti-ulcer activities were evaluated against cold restraint (CRU) and pyloric ligation (PL) induced gastric ulcer models and further confirmed through H(+) K(+)-ATPase inhibitory activity. Cytoprotective activity was evaluated in alcohol (AL) induced gastric ulcer model and further through PGE(2) level. E-EtOH and Fr-Bu attenuated ulcer formation in CRU. Moreover E-EtOH and Fr-Bu displayed potent anti-secretory activity as evident through reduced free acidity and pepsin activity in PL, confirmed further by in vitro inhibition of H(+) K(+)-ATPase activity. In addition cytoprotective potential of E-EtOH and Fr-Bu were apparent with protection in AL model, increased PGE(2) content and enhanced mucin level in PL. Phytochemical investigations of Fr-Bu yielded terpenoides and a phenolic glycoside, verbascoside. The anti-secretory mechanism of verbascoside mediated apparently through inhibition of H(+) K(+)-ATPase with corresponding decrease in plasma gastrin level, is novel to our finding. Gastroprotection elicited by TG might be through proton pump inhibition and consequent augmentation of the defensive mechanism.

Anti-ulcer constituents of Annona squamosa twigs.

Phytochemical investigation of Annona squamosa twigs, resulted in isolation and identification of twelve known (1-12) compounds among them one 1-(4-β-D-glucopyranosyloxyphenyl)-2-(β-D-glucopyranosyloxy)-ethane (11) is synthetically known but first time isolated from natural sources. Their structures were elucidated using 1D and 2D NMR spectroscopic analysis. The isolated compounds (2-8, 11) were evaluated for H(+) K(+)-ATPase activity. Three of these compounds (+)-O-methylarmepavine (2), N-methylcorydaldine (3), isocorydine (6) showed promising anti-secretory activity. Activity of these compounds, comparable to the standard drug omeprazole is novel to our finding. Moreover, there is no information accessible regarding the pharmacological effect of A. squamosa on the gastrointestinal system. This study is the first of its kind to show the significant anti-ulcer effect of A. squamosa. The present study aimed to evaluate the gastroprotective effect of A. squamosa (AS) and to identify its active constituents. Anti-ulcer activity was evaluated against cold restraint (CRU), pyloric ligation (PL), aspirin (ASP), alcohol (AL) induced gastric ulcer and histamine (HA) induced duodenal ulcer model and further confirmed through in vitro assay of H(+) K(+)-ATPase activity and plasma gastrin level. AS and its chloroform and hexane fraction attenuated ulcer formation in CRU, PL, HA model and displayed anti-secretory activity in vivo through reduced free, total acidity and pepsin in PL, confirmed by in vitro inhibition of H(+) K(+)-ATPase activity with corresponding decrease in plasma gastrin level. Cytoprotection of AS was apparent with protection in AL, ASP models and enhanced mucin level in PL.

Cypermethrin induces astrocyte damage: Role of aberrant Ca 2+ , ROS, JNK, P38, matrix metalloproteinase 2 and migration related reelin protein

Cypermethrin is a synthetic type II pyrethroid, derived from a natural pyrethrin of the chrysanthemum plant. Cypermethrin-mediated neurotoxicity is well studied; however, relatively less is known of its effect on astrocyte development and migration. Astrocytes are the major components of blood brain barrier (BBB), and astrocyte damage along with BBB dysfunction impair the tight junction (TJ) proteins resulting in altered cell migration and neurodegeneration. Here, we studied the mechanism of cypermethin mediated rat astrocyte damage and BBB disruption, and determined any change in expression of proteins associated with cell migration. Through MTT assay we found that cypermethrin reduced viability of cultured rat astrocytes. Immunolabelling with astrocyte marker, glial fibrillary acidic protein, revealed alteration in astrocyte morphology. The astrocytes demonstrated an enhanced release of intracellular Ca(++) and ROS, and up-regulation in p-JNK and p-P38 levels in a time-dependent manner. Cypermethrin disrupted the BBB (in vivo) in developing rats and attenuated the expression of the extracellular matrix molecule (ECM) and claudin-5 in cultured astrocytes. We further observed an augmentation in the levels of matrix metalloproteinase 2 (MMP2), known to modulate cellular migration and disrupt the developmental ECM and BBB. We observed an increase in the levels of reelin, involved in cell migration, in cultured rat astrocytes. The reelin receptor, α3β1integrin, and a mammalian cytosolic protein Disabled1 (Dab1) were also up-regulated. Overall, our study demonstrates that cypermethrin induces astrocyte injury via modulation in Ca(++), ROS, JNK and P38 pathways, which may alter MMP expression and reelin dependent astrocyte migration during brain development.

Gastroprotective effect of anti-cancer compound rohitukine: possible role of gastrin antagonism and H+ K+-ATPase inhibition

The present study was designed to evaluate the anti-ulcerogenic properties of an alkaloid chromane, rohitukine from Dysoxylum binectariferum. Anti-ulcer potential of rohitukine was assessed in cold restrained, pyloric ligated and ethanol induced ulcers in rats. In addition, rohitukine was tested in vitro for H+ K+-ATPase inhibitory activity in gastric microsomes. Moreover, we studied the role of rohitukine on the cytosolic concentration of Ca2+ in parietal cell-enriched cell suspension in order to ascertain its mechanism of action. Cytoprotective activity was evaluated through PGE2 level. Rohitukine significantly attenuated the ulcers in cold restraint ulcer (CRU) model in a dose-related manner. Moreover, it significantly lowered the free acidity and pepsin activity in pyloric ligated rats while improved the depleted level of mucin. Furthermore, rohitukine significantly reversed the cold restrained-induced increase in gastrin level. Our in vitro study revealed that rohitukine moderately inhibited the microsomal H+ K+-ATPase activity with respect to positive control omeprazole. Furthermore, rohitukine potently antagonized the gastrin-elicited increase in cytosolic Ca2+ level in parietal cell-enriched suspension. In ethanol-induced gastric lesions in rats, rohitukine significantly inhibited the formation of erosions and increased PGE2 content showing more potency than reference drug sucralfate. Our results thus suggest that rohitukine possess significant anti-ulcer and anti-gastrinic activity in rats. It is likely that gastro-protective influences of rohitukine are dependent partly on its acid-lowering potential and partly on cytoprotective property. The acid-reducing effect of rohitukine might be attributed to its lowering effect on gastrin production and/or antagonism of gastrin-evoked functional responses of parietal cells. Thus, rohitukine represent a useful agent in the treatment of peptic ulcer disease.

Labda‐8(17),12,14‐trien‐19‐oic Acid Contained in Fruits of Cupressus sempervirens Suppresses Benign Prostatic Hyperplasia in Rat and In Vitro Human Models Through Inhibition of Androgen and STAT‐3 Signaling

Fruit extract of Cupressus sempervirens (CS), which is used traditionally to treat Benign Prostatic Hyperplasia (BPH)‐like urinary symptoms in patients, was scientifically validated for anti‐BPH activity. The ethanolic fruit extract of CS inhibited proliferation of human BPH‐stromal cells and the activity was localized to its chloroform‐soluble, diterpene‐rich fraction. Eight major diterpenes isolated from this fraction exhibited moderate to potent activity and the most active diterpene (labda‐8(17),12,14‐trien‐19‐oic acid) exhibited an IC50 of 37.5 μM (antiproliferative activity against human BPH‐stromal cells). It significantly inhibited activation (phosphorylation) of Stat‐3 in BPH‐stromal cells and prevented transactivation of androgen sensitive KLK3/PSA and TMPRSS2 genes in LNCaP cells. Labda‐8(17),12,14‐trien‐19‐oic acid‐rich CS fraction prevented prostatic hyperplasia in rat model and caused TUNEL labeling of stromal cells with lower expressions of IGF‐I, TGF‐ß and PCNA, and bcl‐2/bax ratio. Human BPH tissues exhibited precise lowering of stromal component after incubation in labda‐8(17),12,14‐trien‐19‐oic acid, ex vivo. We conclude that labda‐8(17),12,14‐trien‐19‐oic acid contained in CS exhibits anti‐BPH activity through inhibition of stromal proliferation and suppression of androgen action in the prostate, presenting a unique lead structure for further optimization of anti‐BPH activity. Copyright

Down-regulated GFAPα: a major player in heavy metal induced astrocyte damage

Exposure to a mixture of As, Pb and Cd induces apoptosis and morphological alterations in the cortical astrocytes of rat brain. The levels of the glial fibrillary acidic protein (GFAP) undergo a reduction. The GFAP exists in several isoforms, viz., α, β, κ, δ and ϵ. However, contribution of the isoforms towards astrocyte damage is not understood. We investigated the effect of the metal mixture (MM) on the expression profiles of mRNAs encoding the GFAP isoforms in astrocytes. The MM was administered in drinking water to developing rats till postnatal day (PD) 60. We observed a fall (10.20 ± 1.04%, 18.91 ± 2.12% and 30.26 ± 3.21% at PD24, PD45 and PD60 respectively) in GFAPα. This may have been compensated by a rise in β, κ, and ϵ. The GFAPδ remained unchanged. To determine the role of the GFAPα, we silenced its gene using SiRNA technology in the rat primary astrocytes. We observed a 23.73 ± 1.56% increase in the number of apoptotic cells. The cleaved PARP and Bax levels increased by 2.48 ± 0.14-fold and 3.73 ± 0.23-fold respectively, and the Bcl-2 and Bcl-xl decreased by 2.38 ± 0.08-fold and 1.76 ± 0.09-fold respectively. The change was comparable to the cells treated with MM. Moreover, silencing the GFAPα gene induced a reduction in the area (6.19 ± 0.18-folds), perimeter (12.65 ± 1.68-folds) and the number of processes (5.88 ± 1.5-folds) in the astrocytes, which closely matched the MM-treated ones. Taken together, these observations are the first to show that MM disturbs the composition of the GFAP isoforms, and a suppressed GFAPα promotes apoptosis in the matured rat astrocytes.

Risk factors for antituberculosis drug-induced hepatotoxicity and its association with oxidative stress in North Indian population

Background: Antituberculosis drug-induced hepatotoxicity (anti-TB-DIH) is a worldwide serious medical problem among TB patients. Oxidative stress has also been proposed as one of the possible mechanisms involved in anti-TB-DIH. Aims: The main aim of this study was to evaluate the risk factors for anti-TB-DIH and further, to investigate the possible association of anti-TB-DIH with oxidative stress. Materials and Methods: This prospective cohort study was conducted in 244 TB patients receiving anti-TB treatment. Liver function (ALT, AST, Bilirubin) and oxidative stress parameters (Malondialdehyde, Glutathione, Superoxide dismutase) were estimated before and during the treatment period, along with clinical observation. Results: 14.3% patients developed Anti-TB-DIH. Patients with female gender, low body mass index, extra-pulmonary TB and positive HIV were significant risk factors for anti-TB-DIH. During the treatment period, patients with DIH showed a significant (P<0.0001) higher level of malondialdehyde, superoxide dismutase and a significant (P<0.0001) lower level of glutathione as compared to patients without DIH. Conclusion: In summary, we found that TB patients with female gender, low body mass index, extrapulmonary and positive HIV were at higher risk for anti-TB-DIH. Our finding further conclude that higher level of MDA with altered level of antioxidants in patients with DIH, may be due to oxidative stress-resulting from anti-TB drugs.

Evaluation of genetic and non-genetic factors on foot and mouth disease (FMD) virus vaccine-elicited immune response in Hardhenu ( Bos taurus x Bos indicus ) cattle

Foot and mouth disease (FMD) is the most contagious disease of mammals and a major threat to animal husbandry sector. In India, vaccination with the inactivated trivalent (O, A and Asia1) vaccine is one proven way for protecting the livestock from FMD. However, many outbreaks have been reported in different parts of the country. Therefore, present study was aimed at elucidating the effects of genetic and non-genetic factors on FMD viral vaccine-elicited immune response in Hardhenu cattle. The effect of season of vaccination was not consistent. The effect of status of animal was significant for all the pre and post AB titres except for pre AB titre of serotype O and post AB titre of Asia1.The estimates of heritability for response to vaccination were low to high ranging from 0.11 to 0.45. The highest heritability estimate was obtained for serotype O and the lowest for Asia1. The heritability estimates for pre and post AB titres ranged from 0.15 to 0.33. All the pre and post AB titres and responses to vaccination had genetic correlations ranged from high negative to high positive among them. Results of this study highlight the variation in vaccine response which needs to be further exploited on large-scale animal data for better immunization and protection against highly contagious viral vesicular disease of cloven-hoofed animals.