Inhibition of NO2, PGE2, TNF-α, and iNOS EXpression by Shorea robusta L.: An Ethnomedicine Used for Anti-Inflammatory and Analgesic Activity

This paper is an attempt to evaluate the anti-inflammatory and analgesic activities and the possible mechanism of action of tender leaf extracts of Shorea robusta, traditionally used in ailments related to inflammation. The acetic-acid-induced writhing and tail flick tests were carried out for analgesic activity, while the anti-inflammatory activity was evaluated in carrageenan-and dextran- induced paw edema and cotton-pellet-induced granuloma model. The acetic-acid-induced vascular permeability, erythrocyte membrane stabilization, release of proinflammatory mediators (nitric oxide and prostaglandin E2), and cytokines (tumor necrosis factor-α, and interleukins-1β and -6) from lipopolysaccharide-stimulated human monocytic cell lines were assessed to understand the mechanism of action. The results revealed that both aqueous and methanol extract (400 mg/kg) caused significant reduction of writhing and tail flick, paw edema, granuloma tissue formation (P < 0.01), vascular permeability, and membrane stabilization. Interestingly, the aqueous extract at 40 μg/mL significantly inhibited the production of NO and release of PGE2, TNF-α, IL-1β, and IL-6. Chemically the extract contains flavonoids and triterpenes and toxicity study showed that the extract is safe. Thus, our study validated the scientific rationale of ethnomedicinal use of S. robusta and unveils its mechanism of action. However, chronic toxicological studies with active constituents are needed before its use

Anomalous Price Behaviour around Open Market Stock Repurchase Announcements in India

Executive Summary This article examines the impact of open market share repurchase announcements on stock returns in the Bombay Stock Exchange (BSE). The main objective is to examine whether share repurchase announcements under the open market route have any significant impact on the returns of the stocks traded in the BSE. The article covers the period from 2009 to 2013. For sample selection, two criteria were used: first, the firm should have been listed in the BSE for at least 28 trading days before the repurchase announcement date, and second, the firm should have all relevant data required by this study. A total of 95 repurchase announcements fulfilled these criteria. The analysis period extended from –28 to +28 trading days relative to the repurchase announcement date ( t = 0). The findings of the study will help us to understand how the market responds to share repurchase announcements in India and whether a firm actually benefits by repurchasing its own shares from the market. This study uses a standard event methodology based on an ordinary least squares market model with the aim of finding out whether repurchase announcements generate any abnormal return around the repurchase announcement date. While applying the market model for estimating the abnormal returns, the regression is estimated based on the stock return of the firm and market return of the previous 120 trading days. So, here the estimation window takes into account 120 observations. Using this, the expected returns are generated and then the abnormal returns are derived for the event window, 28 days prior to the event date and 28 days after the event date. The findings of the study indicate that share repurchase announcements do not necessarily generate abnormal stock returns in the Indian equity market unlike developed economies like the US, Canada, and Australia. The whole sample is further divided into various subsamples on the basis of firm size and size of repurchase. The subsample analyses reveal that smaller firms do not necessarily experience higher abnormal stock returns following repurchase announcements than that of the larger firms. The findings weakly support the view that larger repurchase size generates greater abnormal stock returns than the smaller ones

A histopathological study of liver and biliary remnants with clinical outcome in cases of extrahepatic biliary atresia

Context: The indicators of poor prognosis in cases of extrahepatic biliary atresia (EHBA) continue to remain controversial. Aims: To correlate the histopathological findings of wedge biopsy from liver and tissue obtained from the shaving at the porta hepatis, during hepatic portoenterostomy, with the clinical outcome. Materials and Methods: All cases of EHBA surgically treated in our hospital from 1995 to 2006 have been reviewed. Wedge biopsies of the liver and biopsies from the porta hepatis were analyzed with hemotoxylin-eosin stains and immunohistochemistry. The parameters correlated with clinical outcomes were - presence of large bile ducts ( &gt; 150&#956;m diameter) in the portal tissue plaque, degree of fibrosis (semi-quantitative; graded as mild, moderate and severe), presence of ductal plate malformation (DPM) and age at operation. Results: The proportions of patients with small or large ductal diameter who remained clinically controlled (serum bilirubin &lt; 1.5mg/dl with no evidence of end stage liver failure) were 39&#x0025; and 66.6&#x0025; respectively (P=0.44). There was a highly significant correlation between the extent of fibrosis and clinical outcome. Mild, moderate and severe fibrosis resulted in clinical control rates of 78.5&#x0025;, 34.4&#x0025; and 24&#x0025; respectively (P=0.001). Ductal plate malformation was seen in 15&#x0025; of our cases and was uniformly associated with poor outcome. A non-significant trend towards poorer outcome was seen with increasing age at surgery. Conclusions: Histopathological correl ations with clinical outcome in EHBA have been rarely reported from the Indian subcontinent. A greater degree of fibrosis at the time of hepatic portoenterostomy and presence of ductal plate malformation is associated with a significantly poorer clinical outcome

Anti-herpes virus activities of bioactive fraction and isolated pure constituent of <it>Mallotus peltatus</it>: an ethnomedicine from Andaman Islands

Abstract Background Viral infections, particularly the infections caused by herpes simplex virus (HSV), represent one of the most serious public health concerns globally because of their devastating impact. The aim of this study was to evaluate the antiviral potential of methanolic crude extract of an ethnomedicine Mallotus peltatus, its active fraction and pure compound, against HSV-1 F and HSV-2 G. Result The cytotoxicity (CC50, the concentration of 50% cellular toxicity), antiviral effective concentration (EC50, the concentration required to achieve 50% protection against virus-induced cytopathic effect), plaque reduction and the selectivity index (SI, the ratio of CC50 and EC50) was determined. Results showed that the crude methanolic extract of M. peltatus possessed weak anti-HSV activity. In contrast, the active fraction A and isolated ursolic acid from fraction A exhibited potent antiherpesvirus activity against both HSV-1 (EC50 = 7.8 and 5.5 μg/ml; SI = 22.3 and 20) and HSV-2 (EC50 = 8.2 and 5.8 μg/ml, and SI = 21.2 and 18.97). The fraction A and isolated ursolic acid (10 μg/ml) inhibited plaque formation of HSV-1 and HSV-2 at more than 80% levels, with a dose dependent antiviral activity, compared to acyclovir. The time response study revealed that the anti-HSV activity of fraction A and isolated ursolic acid is highest at 2–5 h post-infection. Moreover, the time kinetics study by indirect immunofluorescence assay showed a characteristic pattern of small foci of single fluorescent cells in fraction A- treated virus infected cells at 2 h and 4 h post-infection, suggesting drug inhibited viral dissemination. Further, the PCR study with infected cell cultures treated with fraction A and isolated ursolic acid at various time intervals, failed to show amplification at 48–72 h, like acyclovir treated HSV-infected cells. Moreover, fraction A or isolated ursolic acid showed no interaction in combination with acyclovir. Conclusion This study revealed that bioactive fraction A and isolated ursolic acid of M. peltatus has good anti-HSV activity, probably by inhibiting the early stage of multiplication (post-infection of 0–5 h), with SI value of 20, suggesting its potential use as anti-HSV agents.</p