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Leiden, Netherlands

Yuliana N.D.,Leiden University | Yuliana N.D.,Bogor Agricultural University | Jahangir M.,Leiden University | Korthout H.,Fytagoras BV Plant Science | And 3 more authors.
Obesity Reviews | Year: 2011

The obesity drug development is present not a bright and successful story. So far, drugs reported to be effective, either from synthetic or natural sources, mostly stimulated controversy because of serious adverse effects, which ended with stopping clinical trials or even withdrawal from the market. However, obesity and its comorbidities have become rapidly a major problem in both developed and developing countries. This has encouraged pharmaceutical companies and academia to keep on struggling on developing novel effective but safe obesity drugs, and on characterizing novel obesity drug targets. From existing scientific work on obesity drug discovery and commercial slimming preparations, compounds originating from nature, especially from plants, seem to be the first choice. Traditional belief that herbal medicine is safer than synthetic ones is one of the classical arguments, although scientifically this is not always true (e.g. ban on Ephedra). But in general, it has been widely acknowledged that a plant compound, with its unique scaffolds and rich diversity is an unlimited source of novel lead compounds. This paper aims to summarize all works focused on screening plant materials by targeting important pathways related to energy intake regulation, either by in vivo or in vitro experiments. © 2010 The Authors. obesity reviews © 2010 International Association for the Study of Obesity. Source


Ali K.,Leiden University | Ali K.,Shaheed Zulfiqar Ali Bhutto Institute of Science and Technology | Iqbal M.,Leiden University | Fortes A.M.,Center for Biodiversity | And 4 more authors.
Food Chemistry | Year: 2013

Nuclear magnetic resonance (NMR) spectroscopy and multivariate data analyses methods are applied to the metabolic profiling of different red wines from Portugal. The water, methanol-water (1:1), and methanol fractions from solid phase extraction (SPE) with C18 resin were subjected to in vitro TNFa activity assay. Principal component analysis allowed the clear separation among the different SPE fractions according to the activity. Various supervised data reduction algorithms were tested and compared to highlight the TNF α inhibition by SPE fractions of wines. Partial least squares-discriminant analysis and orthogonal bidirectional PLS-DA were found most effective in discriminating the samples with different activities. By calculating variable importance in the projection, the active ingredients in the high activity samples have been identified as caftaric acid, quercetin, and catechin. Among the different vintages, samples from 2010 vintage were found with maximum anti-TNF α activity. The effectiveness of NMR spectroscopy in combination with chemometrics to identify the possible bioactivity in the several crude extracts is highlighted. © 2013 Elsevier Ltd. All rights reserved. Source


Yuliana N.D.,Leiden University | Yuliana N.D.,Bogor Agricultural University | Korthout H.,Fytagoras BV Plant Science | Wijaya C.H.,Bogor Agricultural University | And 2 more authors.
Critical Reviews in Food Science and Nutrition | Year: 2014

The development of obesity is related to the regulation of energy intake, energy expenditure, and energy storage in the body. Increasing energy expenditure by inducing lipolysis followed by fat oxidation is one of the alternatives which could help to reverse this increasingly widespread condition. Currently, there is no approved drug targeting on stimulation of energy expenditure available. The use of herbal medicines has become a preferred alternative, supported by the classical consensus on the innocuity of herbal medicine vs synthetic drugs, something that often lacks a scientific basis (ban on Ephedra, for example). The inclusion of functional food in the daily diet has also been promoted although its efficacy requires further investigation. This review summarizes the results of recent work focused on the investigation of edible plant materials targeted at various important pathways related to stimulation of energy expenditure. The aim is to evaluate a number of plants that may be of interest for further studies because of their potential to provide novel lead compounds or functional foods which may be used to combat obesity, but require further studies to evaluate their antiobesity activity in humans. © 2014 Copyright Taylor and Francis Group, LLC. Source


Ali K.,Leiden University | Iqbal M.,Leiden University | Korthout H.A.A.J.,Fytagoras BV Plant Science | Maltese F.,Leiden University | And 4 more authors.
Metabolomics | Year: 2012

The identification of active ingredients in crude plant extracts offers great advantages. In this study, nuclear magnetic resonance and chemometrics were used for the screening of in vitro anti-TNFα activity in different berry types. Solid phase extraction was applied and the resulting water, methanol-water (1:1), and methanol fractions were tested for the activity. The methanol-water fraction contained most of the phenolics and showed significantly higher activity than the other two fractions. In the second phase of this study, grapes from 'Trincadeira', 'Touriga Nacional', and 'Aragonês', at four developmental stages were metabolically classified and tested for the TNFα inhibition. The initial stages of grape development, green and veraison, were found more active against TNFα production as compared to the later ripe and harvest stages. Among the cultivars, 'Touriga Nacional' was found to be the most potent inhibitor. Different multivariate data analyses algorithms based on projections to latent structures were applied to correlate the NMR and TNFα inhibition data. The variable importance in the projections plot showed that phenolics like quercetin, myricetin, (+)-catechin, (-)-epicatechin, caftarate, and coutarate, were positively correlated with high activity. This work demonstrates the great potential of NMR spectroscopy in combination with chemometrics for the screening of large set of crude extracts, to study the effects of different variables on the activity, and identifying active compounds in complex mixtures like plant extracts. © 2012 The Author(s). Source


Yuliana N.D.,Leiden University | Yuliana N.D.,Bogor Agricultural University | Iqbal M.,Leiden University | Jahangir M.,Leiden University | And 5 more authors.
Food Chemistry | Year: 2011

The potential health effects of 30 spices, commonly used for daily consumption, were submitted to bioactivity screening with several anti-obesity related bioassays: adenosine A1 receptor binding, cannabinoid CB1 receptor binding, TNF-α and 3T3-L1 adipocytes differentiation induction. Sesame seed and red chilli exhibited high binding activity to the adenosine A1 receptor and nutmeg, mace, black pepper and turmeric to the cannabinoid CB1 receptor, while piment and turmeric showed high inhibition of TNF-α accumulation. Black onion seed proved to be the only spice with high 3T3-L1 adipocyte differentiation induction activity. Several well known major compounds found in these active spices were tested with the respective bioassays but did not show activity. Thus, it appears that other minor compounds or the synergistic effects of different constituents are responsible for the observed activity. © 2010 Elsevier Ltd. All rights reserved. Source

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