Planta Med 2010; 76 - L_3
DOI: 10.1055/s-0030-1264197

Infectious diseases and herbal medicines

L Pieters 1
  • 1Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium

For many years the Laboratory of Pharmacognosy and Pharmaceutical Analysis has been involved in collaborative projects with research institutes in developing countries, where traditional medicine still plays an important role in local health care systems, for economic as well as cultural reasons. The aim of our work is twofold: Firstly, to provide a scientific basis for the therapeutic use of medicinal plants in these countries (or to discourage their use if not), and to sustain the development of standardised herbal medicinal products, the quality of which can be controlled, with proven safety and efficacy; secondly, to characterise lead compounds that can be used to develop new therapeutic agents. During the past years our attention has mainly been focused, from a geographical point of view, on Tanzania, DR Congo and Guinea-Conakry; and from a medicinal point of view, on malaria. A biological screening programme of plants used in Tanzania against infectious diseases led to the selection of Elaeodendron schlechteranum (Celastraceae) and Ormocarmpum kirkii (Papilionaceae) for further investiagtion, based on their antibacterial and antiplasmodial properties, respectively. From E. schlechteranum a quinone-methide triterpene, 22β-hydroxytingenone or tingenin B, with a pronounced activity against a range of microorganisms was isolated, although a high cytotoxicity was observed as well. From O. kirkii a series of (3–3′)-biflavonoids was obtained, including several new ones, showing antiplasmodial activity to a various degree, which allowed to establish some structure-activity relationships. In a screening programme of plants traditionally used in DR Congo against malaria, Nauclea pobeguinii (Rubiaceae) was selected for further investigation. The main constituent of N. pobeguinii was the alkaloid strictosamide, and an HPLC method was developed and validated for the quantification of this compound in an 80% EtOH stem bark extract. The antimalarial activity of this standardised extract was established in vivo, and clinical studies in DR Congo have been initiated in order to provide a herbal medicinal product with proven safety and efficacy for non-severe malaria for the local market.