Pharmaceutical Biology 2004, Vol. 42, Nos. 4–5, pp. 332–337
In Vitro Antiparasitic Activity of Plant Extracts from Panama A. Gómez Barrio1, M.M. Martínez Grueiro1, D. Montero1, J.J. Nogal1, J.A. Escario1, S. Muelas1, C. Fernández1, C. Vega1, M. Rolón1, A.R. Martínez Fernández1, P.N. Solís2 and M.P. Gupta2 1
Departamento de Parasitologia, Facultad de Farmacia, Universidad Complutense, Ciudad Universitaria, Madrid, Spain; Center for Pharmacognostic Research on Panamanian Flora, College of Pharmacy, Estafeta Universitaria, Panama, Republic of Panama 2
Abstract As a contribution to the search of antiparasitic activity in plants from Panama, a total of 37 extracts obtained from 14 species were assessed against Trypanosoma cruzi (Trypanosomatidae), Trichomonas vaginalis (Trichomonadidae), and Heligmosomoides polygyrus (Heligmosomidae). Also, the cytotoxicity to macrophages was determined, in order to discard, among the active extracts, those cytotoxic to mammalian cells. Tripanocidal activity and cytotoxicity to macrophages were performed by a colorimetric method using the tetrazolium salt MTT, assays on T. vaginalis by counting viable protozoa, and the anthelmintic activity was determined by enzymatic assays of acetylcholinesterase and acid phosphatase activities. Extracts from Bixa orellana L. (Bixaceae) and Clusia rosea Jacy. (Clusiaceae) were the most interesting both as antiprotozoan and nematocides. Keywords: Antiparasitic activity, Heligmosomoides polygyrus, plant extracts, Trichomonas vaginalis, Trypanosoma cruzi.
Introduction Parasitic diseases remain a major public health problem affecting hundreds of millions of people, particularly in tropical developing countries. Because of the limited availability and high costs of drugs, the majority of the world’s population depends on traditional remedies, and it is estimated that some 20,000 species of higher plants are used medicinally throughout the world (Tagboto & Townson, 2001). In fact, the use of natural products with therapeutic properties is an ancient practice, which is correctly gaining more acceptance.
The treatment of two protozoan diseases so different both biologically and clinically as trichomoniasis and trypanosomiasis shares a similar problem, that is the variable efficacy of the nitro-derivatives used as drugs of choice (metronidazole and nifurtimox and/or benznidazole, respectively) against different strains of the parasites. Also toxic side effects, limited efficacy during the chronic phase of Chagas disease, and inaccessibility of a large percentage of the world’s population to conventional pharmacological treatment of these and other parasitoses have contributed to the interest in alternative therapies, especially in natural products derived from plants. In the search for new drugs, considerable efforts have been made to identify new compounds from plants in South America and elsewhere, and the mechanisms of action of several active plant products have been studied (De Castro, 1993; Sepulveda-Boza & Cassels, 1996). Unfortunately, those limitations are not exclusive of antiprotozoan therapy but also affect anthelmintics in use. Resistance to broad-spectrum anthelmintics in livestock helminthes, especially gastrointestinal nematodes of sheep and goats, has become a serious problem in many countries (Conder & Campbell, 1995; Waller, 1997), and there is an increased awareness of the potential problem of anthelmintic resistance in the treatment and control of human helminthes (Geerts & Gryseels, 2000). As a contribution to the search for therapeutical alternatives for antiparasitic chemotherapy, we assessed the in vitro activity of a total of 37 extracts obtained from 14 plant species from Panama, within the framework of a international cooperation Iberoamerican Program of Science and Technology for Development, CYTED.
Accepted: May 11, 2004 Address correspondence to: A. Gómez Barrio, Departamento de Parasitologia, Facultad de Farmacia, Universidad Complutense, Ciudad Universitaria 28040 Madrid, Spain. E-mail:
[email protected] DOI: 10.1080/13880200490511945
© 2004 Taylor & Francis Ltd.
Antiparasitic activity of Panamanian plants
Materials and Methods Plant collection and extracts The following plants were evaluated: Aegiphila anomala Pittier (Verbenaceae), Albizia adinocephala (Donn. Sm.) Britton & Rose (Fabaceae), Andira inermis (W. Wright) Kunth ex DC. (Fabaceae), Bixa orellana L. (Bixaceae), Clusia rosea Jacq. (Clusiaceae), Clusia coclensis Standl. (Clusiaceae), Lonchocarpus chiricanus Pittier (Fabaceae), Miconia schlimii Triana (Melastomataceae), Morinda panamensis Seem. (Rubiaceae), Morinda rojoc L. (Rubiaceae), Parathesis amplifolia Lundell (Myrsinaceae), Piper fimbrilatum C.DC. (Piperaceae), Chrysochlamys tenuis Hammel (Clusiaceae), and Trichospermum galeottii (Turcz.) Kosterm. (Tiliaceae). Plants were collected from the places and on dates indicated in Table 1 and were identified by Professor Mireya Correa, Director of the University of Panama Herbarium, where voucher specimens are deposited. Appropriate solvent was added to the dried ground plant material and macerated twice for 24 h, adding fresh solvent each time. After filtration, extracts were dried in vacuo at a temperature
