Preeti Jain

DPP-4 inhibitor sitagliptin prevents inflammation and oxidative stress of heart and kidney in two kidney and one clip (2K1C) rats

BackgroundHyperglycemia and insulin resistance often develop cardiovascular and nephrological dysfunction in diabetic patients. Sitagliptin is used to treat diabetes and showed potential benefit in lowering increased blood glucose level in diabetes. This investigation reports the effect of sitagliptin treatment on oxidative stress in kidney and heart of 2K1C rats.MethodsMale Long Evans rats underwent unilateral surgical stenosis of the renal artery [2-kidney-1-clip (2K1C) method]. These animals entered a 4-weeks dosing period with sitagliptin. Blood and urine sampling and organ harvesting were finally performed. Blood plasma, heart, kidney tissues and urine were tested for the assessment of inflammation and oxidative stress in kidney and heart of 2K1C rats after 4xa0weeks of surgery.Results2K1C rats showed cardiac hypertrophy, increased left ventricular wet weight compared to sham which was not significantly altered by sitagliptin treatment. Uric acid and creatinin concentrations were also increased in 2K1C rats. Sitagliptin significantly prevented the elevation of uric acid and creatinin concentration in plasma and urine in this rat model. Oxidative stress markers in plasma such as malondialdehyde (MDA), nitric oxide (NO), and advanced protein oxidation product (APOP) concentrations were increased in the 2K1C rats as compared to sham-operated animals. Increased concentrations of these oxidative stress markers were also normalized by sitagliptin treatment. 2K1C rats also showed increased level of uric acid and creatinine both in plasma and urine; which are also reduced to normal level in sitagliptin treated rats. Moreover, 2K1C surgery initiated inflammatory cell infiltration, increased MPO activity and fibrosis in both heart and kidneys which were further ameliorated by sitagliptin treatment.ConclusionOur study suggests that sitagliptin treatment in 2K1C rats prevented inflammation and fibrosis of heart and kidney by ameliorating elevated oxidative stress in heart and kidney tissues.

Beneficial Role of Bitter Melon Supplementation in Obesity and Related Complications in Metabolic Syndrome

Diabetes, obesity, and metabolic syndrome are becoming epidemic both in developed and developing countries in recent years. Complementary and alternative medicines have been used since ancient era for the treatment of diabetes and cardiovascular diseases. Bitter melon is widely used as vegetables in daily food in Bangladesh and several other countries in Asia. The fruits extract of bitter melon showed strong antioxidant and hypoglycemic activities in experimental condition both in vivo and in vitro. Recent scientific evaluation of this plant extracts also showed potential therapeutic benefit in diabetes and obesity related metabolic dysfunction in experimental animals and clinical studies. These beneficial effects are mediated probably by inducing lipid and fat metabolizing gene expression and increasing the function of AMPK and PPARs, and so forth. This review will thus focus on the recent findings on beneficial effect of Momordica charantia extracts on metabolic syndrome and discuss its potential mechanism of actions.

Induction of Cr(VI) reduction activity in an Anoxybacillus strain under heat stress: a biochemical and proteomic study

A bacterial strain, designated as TSB-6, was isolated from the sediments of a Tantloi (India) hot spring at 65 °C. The strain showed 98% 16S rRNA gene sequence similarity with Anoxybacillus kualawohkensis strain KW12 and was found to grow optimally at 37 °C. However, growing cells, cell suspensions, and cell-free extracts from 65 °C cultures showed higher Cr(VI) reduction activities when assayed at either 37 or 65 °C than those obtained from 37 °C cultures. On fractionation of extracts from cells grown at 65 °C, the chromate reductase activity assayed at 65 °C was found mostly in the soluble fraction. When log-phase cells growing at 37 °C were shifted to 65 °C, the stressed cells produced larger quantities of reactive oxygen species. Consequently, growth of the cells was retarded, but specific Cr(VI) reduction activity increased. 2D gel electrophoresis followed by MALDI-TOF MS/MS identified the proteins whose expression level changed as a result of heat stress. The upregulated set included proteins involved in cellular metabolism of sugar, nucleotide, amino acids, lipids and vitamins, oxidoreductase activity, and protein folding. The downregulated proteins are also involved in cellular metabolism, DNA binding, and environmental signal processing.

Angiotensin-converting enzyme inhibitor prevents oxidative stress, inflammation, and fibrosis in carbon tetrachloride-treated rat liver

Abstract Hepatic fibrosis is a common feature of chronic liver injury, and the involvement of angiotensin II in such process has been studied earlier. We hypothesized that anti-angiotensin II agents may be effective in preventing hepatic fibrosis. In this study, Long Evans female rats were used and divided into four groups such as Group-I, Control; Group-II, Controlu2009+u2009ramipril; Group-III, CCl4; and Group-IV, CCl4u2009+u2009ramipril. Group II and IV are treated with ramipril for 14 d. At the end of treatment, the livers were removed, and the level of hepatic marker enzymes (aspartate aminotransferase, Alanine aminotransferase, and alkaline phosphatase), nitric oxide, advanced protein oxidation product , catalase activity, and lipid peroxidation were determined. The degree of fibrosis was evaluated through histopathological staining with Sirius red and trichrome milligan staining. Carbon-tetrachloride (CCl4) administration in rats developed hepatic dysfunction and raised the hepatic marker enzymes activities significantly. CCl4 administration in rats also produced oxidative stress, inflammation, and fibrosis in liver. Furthermore, angiotensinogen-inhibitor ramipril normalized the hepatic enzymes activities and improved the antioxidant enzyme catalase activity. Moreover, ramipril treatment ameliorated lipid peroxidation and hepatic inflammation in CCl4-treated rats. Ramipril treatment also significantly reduced hepatic fibrosis in CCl4-administered rats. In conclusion, our investigation suggests that the antifibrotic effect of ramipril may be attributed to inhibition of angiotensin-II mediated oxidative stress and inflammation in liver CCl4-administered rats.

Human Umbilical Cord Lining Cells as Novel Feeder Layer for Ex Vivo Cultivation of Limbal Epithelial Cells.

PURPOSEnTo determine the effectiveness of human umbilical cord-derived mucin-expressing cord lining epithelial cells (CLEC-muc) as feeder cells in a coculture system for the cultivation of human limbal stem cells.nnnMETHODSnHuman CLEC-muc were cultured in PTTe-1 medium and treated with mitomycin C to arrest their growth to make the feeder layer. Single-cell suspension of limbal cells was prepared from corneal rim collected from the Singapore Eye Bank. Limbal cells were cultured in a coculture system with CLEC-muc as well as 3T3 cells as feeder layer. We compared the colony-forming efficiency and cell morphology of the limbal cells cultured in the two different feeder layers. We also compared the expression level of several putative limbal stem cell markers, such as HES1, ABCG2, ΔNP63, and BMI1, in the cultured limbal cells by immunostaining and quantitative (q)RT-PCR. Expression of cytokeratins CK14, CK15, CK19, CK3, and CK4 was further compared.nnnRESULTSnHuman limbal epithelial cells cultured in both types of feeder layers showed comparable cell morphology and colony-forming efficiency. These cells exhibited a similar expression pattern of HES1, ABCG2, ΔNP63, BMI1, CK14, CK15, CK19, and CK3 as detected by immunostaining and PCR.nnnCONCLUSIONSnHuman CLEC-muc may be a suitable alternative to conventional mouse 3T3 feeder cells, which may reduce the risk of zoonotic infection.

Market Reaction to Stock Dividends: Evidence from India

Theoretically, stock dividends have no impact on financial position of the announcing company as net worth and total assets remain the same, though empirical evidence across the globe shows that markets react to stock dividend announcements. The present study analyses the market reaction pertaining to stock dividend decisions in the Indian context. Market reaction has been captured in terms of impact on returns, liquidity, and risk. The sample includes 51 ‘pure’ stock dividend announcements from January 1, 2002 to June 30, 2010. The study finds that the announcement of stock dividends induces an increase in the wealth of the shareholders in India. A consistent pattern of positive average abnormal returns during the pre-announcement window till the announcement day and a pattern of negative average abnormal returns during the post-announcement window have been observed. On cumulating these results, the shareholders of the companies that issued stock dividends gain significant returns. The justification for such results seems to be that the information about the stock dividends announcement reaches the investors prior to the decision date as it is manda-tory for the issuing company to inform the exchange (where it is listed) about the date of the board meeting. It has been observed that the companies usually inform the exchange seven days prior to the day of the board meeting. In most of the cases, the companies provide the agenda item information along with the board meeting date to the exchange. In such a situation, the moment this information about the agenda item is given to the exchange, this becomes public information and investors start reacting to it. The cumulative average abnormal return values over various size event windows depict that an investor can earn substantial returns if he purchases the shares on the day the news of board meeting (to announce stock dividends) comes to the market and sells them one day after the announcement day. The investor can also gain if the shares are purchased one day prior to the announcement day and are sold one day after the announcement day. The trading quantity reduces significantly immediately after these decisions are announced. On a short-term basis, the investors seem to perceive that the announcement of stock dividends provides signals about the firms bright future prospects. This leads to a decline in trading quantity as investors, who own the shares at the time of announcement, prefer to hold the shares expecting an increase in their wealth in future. In the long-run, a marginally positive impact has been observed. The announcement of stock dividends reduces variability of returns in the short-run as well as in the long run, lending price stability to the stocks of the announcing companies.

Molecular phylogenetic analysis of bacterial community and characterization of Cr(VI) reducers from the sediments of Tantloi hot spring, India

BackgroundA geothermal ecosystem located at Tantloi, India has been found to be an interesting habitat for microbes of diverse nature. However, the microbial diversity of this habitat is poorly explored. In this study, a detailed phylogenetic study has been carried out to understand the bacterial diversity of this habitat and to identify prospective metal reducers using culture independent approach. The bacterial diversity of the sediments, which contain undetectable levels of Cr(VI), was analysed with respect to chromium reduction and the strains highly resistant to and efficiently reducing chromium under aerobic conditions were isolated and characterized.Results16S rRNA gene sequence analysis of Tantloi hot spring microbial community revealed a significant bacterial diversity represented by at least ten taxonomic divisions of Bacteria with clear predominance of Thermus. Similar sequence analysis of rRNA gene library clones derived from bacterial consortia enriched from sediments in presence of Cr(VI) revealed the abundance of the family Bacillaceae. Under aerobic conditions at 65°C, the consortia reduced 1xa0mM of Cr(VI) completely within 24xa0h and 5xa0mM in 6xa0days. A complete reduction of 1xa0mM Cr(VI) has been shown by five of our isolates within 36xa0h. 16S rRNA gene sequences of all the isolates showed high degree of similarity (97-99%) to Bacillaceae with ten of them being affiliated to Anoxybacillus. Crude extract as well as the soluble fraction from isolates TSB-1 and TSB-9 readily reduced Cr(VI); TSB-1 showed higher chromium reductase activity.ConclusionMost of the Tantloi Spring Bacterial (TSB) sequences analyzed in different taxonomic divisions could be related to representatives with known metabolic traits which indicated presence of organisms involved in redox processes of a variety of elements including iron, sulphur and chromium. Approximately 80% of the sequences obtained in this study represented novel phylotypes indicating the possibility of discovery of bacteria with biotechnologically important new biomolecules. Again, highly chromium-resistant and remarkably active Cr(VI)-reducing Anoxybacillus strains isolated in this study could serve as potential candidates for designing chromium bioremediation strategies at high temperatures and also at high chromium concentrations.

Pretreatment With Risperidone Ameliorates Systemic LPS-Induced Oxidative Stress in the Cortex and Hippocampus

Risperidone (RIS), an atypical antipsychotic has been found to show anti-inflammatory effect against lipopolysaccharide (LPS)-induced inflammation. In vitro study has revealed that RIS inhibits the LPS-induced reactive oxygen species (ROS) formation. We investigated the antioxidant effects of RIS on LPS-induced oxidative stress markers in Swiss albino mice. Ten weeks old male Swiss albino mice (30 ± 2 g) were pretreated with either distilled water (control) or RIS (3 mg/kg) for 7 days. On day 8, animals were challenged with a single dose of LPS (0.8 mg/kg) while control animals received distilled water only. The animals were sacrificed after 24 h of LPS administration and tissue samples were collected. RIS administration significantly (p < 0.05) reduced the LPS-induced elevated levels of lipid peroxidation product malondialdehyde (MDA), advanced protein oxidation products, and nitric oxide (NO) in the cortex. Catalase (CAT) and superoxide dismutase (SOD) levels were also diminished while the level of glutathione (GSH) was enhanced. Hippocampus data showed that RIS significantly (p < 0.05) reduced the LPS-induced increased levels of MDA and NO, and SOD activity. Our results suggest that LPS-induced neuronal oxidative damage can be alleviated by the pretreatment with RIS and the effect is shown presumably by scavenging of the ROS by risperidone as an antioxidant.

Antinociceptive and Anti-Inflammatory Activities of Mycetia longifolia (Wall.) O. Kuntze

Mycetia longifolia is used traditionally for the treatment of pain, inflammation, ulcers, and wounds. Phytochemical analysis revealed the presence of alkaloids, flavonoids, tannins, glycosides, and polyphenols. The ethanol extract of the plant was investigated for its antinociceptive and anti-inflammatory activities in mice models and compared to the reference drug diclofenac sodium and control. In the acetic acid-induced writhing model, the extract showed a good antinociceptive effect characterized by the reduction in the number of writhes. The percent inhibition of writhing response by the extract was 74.56% at 500 mg.kg−1 dose. The extract caused decrease in licking time and licking frequency in mice when placed on a hot plate. The extract at doses of 250 and 500 mg.kg−1 b.w. inhibited the formation of paw edema induced by carrageenan.

Phytochemical and pharmacological investigation of ethanol extract of Cissampelos Pareira

In this study, the ethanol extract of Cissampelos pareira has been evaluated. The extract was tested for analgesic properties using both hot plate and acetic acid-induced writhing methods. Antiinflammatory effect was investigated using two different doses of 250 and 500 mg/kg body weight on Evans rats by carrageenan-induced paw edema test. The antipyretic activity was evaluated using Brewers yeast-induced pyrexia in Wistar rats. The phytochemical screening of the extract of Cissampelos pareira exhibited the presence of several phytochemical compounds including saponins, gums and carbohydrates, reducing sugars, alkaloids and terpenoids. Ethanol extract of Cissampelos pareira exhibited significant analgesic, antiinflammatory and antipyretic activity in a dose-dependent manner. The results obtained from these studies confirm its therapeutic value against diseases caused by various pain and fever.