Special Issue "Plant Natural Products against Human Parasites"
A special issue of Molecules (ISSN 1420-3049).
Deadline for manuscript submissions: closed (30 June 2013)
Prof. Dr. Michael Wink
Institute of Pharmacy & Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
Phone: +49 6221 544881
Fax: +49 6221 544884
Interests: molecular systematics and phylogeny of birds; reptiles; fish; insects and plants (genetic diversity); plant secondary metabolites (phytochemistry, biochemistry and molecular pharmacology): diversity of natural products
Plants produce a high diversity of secondary metabolites (SM) which have evolved as means against herbivores and microbial pathogens SM additionally serve as UV protective and signal compounds. Because SM have been shaped and selected in million years of evolution, they are biologically active and therefore useful in medicine to treat health disorders and diseases. Especially in the treatment of infectious diseases SM have served an important role in human history but could also be of relevance in the future. During the evolution of humans a wide range of parasites have evolved, that uses us as a host organism. Usually a parasite will not kill its host (at least not immediately), as this would by a dead end for a parasite. However, most parasites are either unpleasant for us (think of lice and fleas) or weaken our health (most internal parasites). However, a few parasite infections, such as malaria, trypanosomiasis or Chagas can be deadly if the patients are not treated with adequate therapeutics. Because humans usually live in close proximity and often without good hygienic conditions a transmission of parasites within a human population is often facilitated.
Unfortunately, infections by endoparasites can hardly be prevented by vaccination. Even for malaria, one of the most common parasitic diseases which infects over 200 million people and kills more than 1 million per year, an effective vaccine is not (yet) available because the parasites have clever strategies to outcompete our immune system, for example by continuously changing their surface coat. Medicinal chemists have synthesized a number of drugs which can be used against many but by far not all endoparasites. A major problem is that many drugs have been developed many years ago and some parasitic strains have become resistant to them. The development of new antiparasitic drugs has not much priority in the pharmaceutical industries because many of the parasitic diseases occur in poor countries which cannot afford to pay a high price for the drugs. Thus an investment for drug development against parasitic diseases is a risky affair.
An alternative to synthetic drugs is the search of secondary metabolites or of plant extracts. Natural products still play an important role in therapy: Between 1981 and 2006 1184 new drugs were registered of which 28% were natural products or their derivatives. Another 24% of the new drugs had pharmacophores derived from natural products. This special issue of Molecules welcomes previously unpublished manuscripts covering all aspects of natural products (including extracts) in relationship to parasites and parasitic diseases, including phytochemistry, pharmacology, methodology development and applications.
Prof. Dr. Michael Wink
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed Open Access monthly journal published by MDPI.
- phytochemistry of antiparasitic natural products
- pharmacology of antiparasitic natural products
- molecular modes of action of antiparasitic natural products
- clinical experience with antiparasitic natural products
- new experimental systems to study antiparasitic natural products
Article: Assessment of the Anti-Protozoal Activity of Crude Carica papaya Seed Extract against Trypanosoma cruzi
Molecules 2013, 18(10), 12621-12632; doi:10.3390/molecules181012621
Received: 27 August 2013; in revised form: 20 September 2013 / Accepted: 23 September 2013 / Published: 11 October 2013| PDF Full-text (617 KB)
Molecules 2013, 18(7), 7761-7847; doi:10.3390/molecules18077761
Received: 20 May 2013; in revised form: 23 June 2013 / Accepted: 26 June 2013 / Published: 3 July 2013| Cited by 1 | PDF Full-text (1179 KB)
Article: Design, Synthesis and Trypanocidal Evaluation of Novel 1,2,4-Triazoles-3-thiones Derived from Natural Piperine
Molecules 2013, 18(6), 6366-6382; doi:10.3390/molecules18066366
Received: 29 March 2013; in revised form: 16 May 2013 / Accepted: 21 May 2013 / Published: 29 May 2013| Cited by 1 | PDF Full-text (233 KB)
Communication: Anthraquinones of the Roots of Pentas micrantha
Molecules 2013, 18(1), 311-321; doi:10.3390/molecules18010311
Received: 4 December 2012; in revised form: 19 December 2012 / Accepted: 20 December 2012 / Published: 27 December 2012| Cited by 2 | PDF Full-text (310 KB) | Supplementary Files
Molecules 2012, 17(11), 12771-12791; doi:10.3390/molecules171112771
Received: 12 September 2012; in revised form: 19 October 2012 / Accepted: 26 October 2012 / Published: 31 October 2012| Cited by 4 | PDF Full-text (289 KB)
The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.
Type of Paper: Review
Title: Natural Products from Amazonian Plants: Perspectives for Drug Leads for Vivax and Falciparum Malaria
Authors: Adrian Martin Pohlit 1 and Fabio Trindade Maranhão Costa 2
Affiliations: 1 National Institute for Amazon Research (INPA), Manaus, Amazonas, Brazil
2 University of Campinas, Campinas, São Paulo, Brazil
Abstract: In the Amazon region, there is a rich local tradition of use of plant remedies to treat malaria and also the predominance of Plasmodium vivax and P. falciparum malaria parasite infections in the human population. Traditionally used plants are the sources of the antimalarial natural products quinine and artemisinin and the related classes of synthetic quinoline and semi-synthetic artemisinin antimalarials which make up most of the therapeutic arsenal available to mankind today, including the ACTs (Artemisinin Combined Therapies). In the Amazon region and other parts of the world, P. falciparum and P . vivax parasites are now resistant to, or showing signs of resistance to, chloroquine and other available antimalarial drugs used in therapy. Thus, there is a need for novel chemical entities having new mechanisms of antiplasmodial action and capable of blocking transmission of Plasmodium spp. from humans to Anopheles mosquito vectors and protecting the human liver from initial infection by Plasmodium spp. (prophylaxis). Plant extracts having important in vivo antimalarial activity in animal models or in vitro*activity against *P. falciparum have been described and are important starting points for chemical fractionation and isolation of natural products. Since 2006, researchers from FMT-HVD (Heitor Vieira Dourado Tropical Medicine Foundation), Embrapa (Brazilian Agronomic and Husbandry Research Company) and UFAM (Federal University of Amazonas) under the leadership of INPA´s (National Institute for Amazon Research´s) Laboratory of Amazonian Active Principles (LAPAAM) in Manaus, Amazonas State, Brazil have published work on: the composition of antimalarial plants from the Amazon jungle, the in vitro activity against standardized and field isolated strains of P. falciparum and the in vivo activity in P. berghei-infected mice of extracts and isolated natural products from plants and their semi-synthetic derivatives. Thus, the indole alkaloids ellipticine and aspidocarpine, the quassinoid neosergeolide and the biosynthetically mixed phenylpropyl-terpene 4-nerolidylcatechol and its more stable semi-synthetic derivatives exhibiting sub-micromolar IC50 values in vitro against P. falciparum have been described. Also, strong inhibition of P. berghei in infected mice by ellipticine and O,O-diacetyl nerolidylcatechol at 10-25mg/kg/day in the 4-day suppressive test have been described for the first time recently by LAPAAM. In collaboration with USP (University of São Paulo) a mechanism of antiplasmodial action of derivatives of 4-nerolidylcatechol has been shown to be inhibition of the biosynthesis of essential terpene metabolites within P. falciparum. In the future, these and other substances derived from Amazonian plants will be evaluated for in vitro activity against clinical samples of P. vivax in limited culture and for transmission-blocking and prophylactic activity of P. berghei in different laboratory models. Derivatives of ellipticine and 4-nerolidylcatechol are believed to have potential as lead compounds for the development of new antimalarial drugs.
Last update: 3 April 2013