http://memorias.ioc.fiocruz.br/issues/special-issues/item/1180-a-review-of-antimalarial-plants-used-in-traditional-medicine-in-communities-in-portuguese-speaking-countries-brazil-mozambique-cape-verde-guinea-bissau-s%C3%A3o-tom%C3%A9-and-pr%C3%ADncipe-and-angola
Jefferson Rocha de A SilvaI; Aline de S RamosII; Marta MachadoIII; Dominique F de MouraI; Zoraima NetoIII; Marilene M Canto-CavalheiroIV; Paula FigueiredoIII; Virgilio E do RosárioIII; Ana Claudia F AmaralII; Dinora LopesIII, +
Jefferson Rocha de A SilvaI; Aline de S RamosII; Marta MachadoIII; Dominique F de MouraI; Zoraima NetoIII; Marilene M Canto-CavalheiroIV; Paula FigueiredoIII; Virgilio E do RosárioIII; Ana Claudia F AmaralII; Dinora LopesIII, +
ILaboratório de Cromatografia, Departamento de Química, Universidade Federal do Amazonas, Manaus, AM, Brasil
IILaboratório de Plantas Medicinais e Derivados, Departamento de Produtos Naturais, Farmanguinhos
IIIUnidade de Parasitologia, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal
IVInstituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
IILaboratório de Plantas Medicinais e Derivados, Departamento de Produtos Naturais, Farmanguinhos
IIIUnidade de Parasitologia, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal
IVInstituto Oswaldo Cruz-Fiocruz, Rio de Janeiro, RJ, Brasil
Abstract
The isolation of bioactive compounds from medicinal plants, based
on traditional use or ethnomedical data, is a highly promising
potential approach for identifying new and effective antimalarial drug
candidates. The purpose of this review was to create a compilation of
the phytochemical studies on medicinal plants used to treat malaria in
traditional medicine from the Community of Portuguese-Speaking Countries
(CPSC): Angola, Brazil, Cape Verde, Guinea-Bissau, Mozambique and São
Tomé and Príncipe. In addition, this review aimed to show that there are
several medicinal plants popularly used in these countries for which
few scientific studies are available. The primary approach compared the
antimalarial activity of native species used in each country with its
extracts, fractions and isolated substances. In this context, data shown
here could be a tool to help researchers from these regions establish a
scientific and technical network on the subject for the CPSC where
malaria is a public health problem.
key words:
Malaria is a serious parasitic disease from tropical regions caused by a species of Plasmodium and transmitted by Anopheles
mosquitoes. It is prevalent in approximately 100 countries in Africa,
Southeast Asia and South America, where approximately 2.4 million people
are at risk (Kager 2002). According to the World Malaria Report (WHO
2009a), there are approximately 250 million malaria cases and
approximately one million people die from malaria each year.The emergence and rapid spread of multidrug-resistant strains of Plasmodium, particularly Plasmodium falciparum, represent a major problem for prophylaxis and treatment, which becomes more difficult and limits the choice of drugs used. This has been identified as the current primary cause of control failure.
The well-known use of chloroquine (CQ) and antifolates [sulfadoxine-pyrimethamine (S/P)] for malaria treatment are no longer effective in most endemic areas. Combination therapy has emerged as the best practical solution in overcoming the resistance of select strains. Therapeutics based on combinations with artemisinin and derivatives (ACTs), recommended by the World Health Organization (WHO), presently represent the most effective treatment of P. falciparum malaria infection (WHO 2008). Clinical resistance to these combinations has been recently reported in Cambodia (Noedl et al. 2008), suggesting that P. falciparum parasites have already developed the ability to grow in the presence of these antimalarials, which strongly suggests the need for further research into new antimalarials.
There is broad consensus on the urgent need for new, affordable and efficient compounds that could serve as primary molecules for antimalarial treatment. New highly-effective antimalarial drug candidates, based on new mechanisms of action or with new structures, are urgently needed to overcome the problem of rapid emergence of drug resistance and achieve long-term clinical efficacy.
Due to the crucial role that plant-derived compounds have played in drug discovery and development for the treatment of several diseases, the isolation of new bioactive compounds from medicinal plants based on traditional use or ethnomedical data appears to be a very promising approach (Newman 2008, Turschner & Efferth 2009).
There is a consensus among the scientific community that natural products have a dominant presence in discovering new leads for the development of drug treatment for human diseases. In fact, of the 877 novel medicines that were developed in the period between 1981-2002, 6% were natural products, 27% were derivatives of natural products and 16% were synthetics developed based on a natural product (Newman et al. 2003). At least 80% of the world population is estimated to be continuing use of such traditional medicines in primary health care, including 40,000-70,000 medicinal plants, approximately 20% of all higher-plant species (Verpoorte et al. 2006). In most cases, very little is known about the plants used in folk medicines.
In malaria therapy, 11 drugs out of the antimalarials included in WHO therapeutic schemes for malaria treatment are natural products or their analogues or were design-based on the pharmacophores from natural products (Bourdy et al. 2008). The great significance of plant-derived drugs for the treatment of the disease is highlighted by quinine (derived from Cinchona tree), artemisinin (derived from Artemisia annua) and atovaquone (Malarone®), which is a synthetic compound (2-alkyl-3-hydroxynaphthoquinone) analogue of lapachol from the Tabebuia species (Bignoniaceae) (Oliveira et al. 2009).
This review was based on compilation of medicinal plants used in traditional medicine in the treatment of malaria infections in some countries of the Community of Portuguese-Speaking Countries (CPSC), which includes Angola, Brazil, Cape Verde, Guinea-Bissau, Mozambique and São Tomé and Príncipe (STP) and involved the comparison of popularly used native species and studies on the antimalarial activity of extracts, fractions and isolated substances.
