Showing papers by "Alexander I. Gray published in 2012"

Resveratrol dimers are novel sphingosine kinase 1 inhibitors and affect sphingosine kinase 1 expression and cancer cell growth and survival

Abstract: Sphingosine kinase 1 catalyses formation of the bioactive lipid, sphingosine 1-phosphate, which protects cancer cells from apoptosis. Therefore, sphingosine kinase 1 is a novel target for intervention with anti-cancer agents. We have assessed the effect of the anti-cancer agent, resveratrol and its dimers (ampelopsin A and balanocarpol) on sphingosine kinase 1 activity and on survival of MCF-7 breast cancer cells. Ampelopsin A and balanocarpol were purified from Hopea dryobalanoides and their effect on sphingosine kinase 1 activity and expression, [3H] thymidine incorporation, ERK-1/2 phosphorylation and PARP activity assessed in MCF-7 cells. Resveratrol, ampelopsin A and balanocarpol were novel inhibitors of sphingosine kinase 1 activity. Balanocarpol was a mixed inhibitor (with sphingosine) of sphingosine kinase 1 with a Kic= 90 +/- 10 mu M and a Kiu of similar to 500 mu M. Balanocarpol and ampelopsin A also induced down-regulation of sphingosine kinase 1 expression and reduced DNA synthesis, while balanocarpol stimulated PARP cleavage in MCF-7 breast cancer cells. Resveratrol was a competitive inhibitor (with sphingosine) of sphingosine kinase 1 with a Kic= 160 +/- 40 mu M, reduced sphingosine kinase 1 expression and induced PARP cleavage in MCF-7 cells. Each molecule of balanocarpol may bind at least two sphingosine kinase 1 catalytic molecules to reduce the activity of each simultaneously. These findings suggest that resveratrol, ampelopsin A and balanocarpol could perturb sphingosine kinase 1-mediated signalling and this might explain their activity against MCF-7 breast cancer cells. This article is commented on by Hergst and Yun, pp. 16031604 of this issue. To view this commentary visit

Natural products isolation in modern drug discovery programs.

Abstract: Natural products play a vital role in drug discovery. They have served as the basic reference and initiators in drug discovery programs. Natural products as pure compounds have been involved in western medicine as drugs or lead compounds for drug discovery and development. In traditional medicine, they have been involved for a very long time as medicinal extracts, infusions, decoctions, or other therapeutic preparations. Modern drug discovery programs require an arsenal of drug candidate molecules in pure form whose activities (usually against cells or enzymes) are rapidly determined using high-throughput screening (HTS) and activities are expected in micro- (μM) to nanomolar (nM) levels. The difficulty in meeting today's standards for drug candidate molecules poses the question: are natural products still relevant in modern drug discovery programs? This and other issues, including the spectroscopic investigation of crude extracts, are discussed.

Scientific Investigation of Antitrypanosomal Activity of Crateva Adansonii DC Leaves Extracts

Abstract: Crateva adansonii DC is used in traditional medicines in the West of Africa. The crude hexane (CAN-1) and ethyl acetate (CAN-2) extracts were evaluated for their in vitro bioactivity against African trypanosome Trypanosoma brucei brucei (S427) blood stream forms. The crude extracts showed moderate anti-trypanosomal activity (MIC 12.5µg/ml). We recommend its use either alone or in combination with other natural/semi-synthetic/synthetic drugs for the treatment of Human African Trypanosomiasis. © 2011 IGJPS. All rights reserved.

Parmeliaceae- An Important Family of Lichens with Medicinal Importance

Abstract: Corresponding Author:Dr. John O Igoli,Assistant Professor, Natural Product Laboratories, SIPBS, University of Strathclyde, 161 Cathedral StreetGlasgow G4 0RE, - United KingdomSubmitting Author:Mr. Rajeev K Singla,Principal Investigator, Division of Biotechnology, Netaji Subhas Institute of Technology, University of Delhi, AzadHind Fauz Marg, Sector-3, Dwarka-110078 - IndiaArticle ID: WMC003807Article Type: Review articlesSubmitted on:04-Nov-2012, 11:47:16 AM GMT Published on: 06-Nov-2012, 07:48:19 PM GMTArticle URL: http://www.webmedcentral.com/article_view/3807Subject Categories:PHARMACEUTICAL SCIENCES Keywords:Parmeliaceae; Lichen; Medicinal Plants; Herbal Plants; Traditional Medicine; PharmacologyHow to cite the article:Kantheti P, Igoli JO, Gray AI, Clements CJ, Singla RK. Parmeliaceae- An ImportantFamily of Lichens with Medicinal Importance . WebmedCentral PHARMACEUTICAL SCIENCES2012;3(11):WMC003807Copyright: This is an open-access article distributed under the terms of the Creative Commons AttributionLicense(CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided theoriginal author and source are credited.Source(s) of Funding:It is a net based article collecting and compiled data from google, google scholar, science direct, Springer, Wiley,Pub Med etc.Competing Interests:No competing interests