Trypanocidal Constituents in Plants 5. Evaluation of Some Mexican Plants for Their Trypanocidal Activity and Active Constituents in the Seeds of Persea americana

Abstract

As a preliminary screening test for the trypanocidal activity against epimastigotes of Trypanosoma cruzi in vitro, we examined some crude extracts of Mexican medicinal plants. 2)T. cruzi is the etiological agent for Chagas' disease (American trypanosomiasis), one of the most serious protozoan diseases in Latin America. Then we started on identification of the principal compounds of the active extracts seeking new chemotherapeutic agents for Chagas' disease. Lignans 2) from Guaco (roots of Aristolochia taliscana) and xanthones 3) from Bari (stems of Calophyllum brasiliense) were isolated as active components against epimastigotes in vitro.T. cruzi exhibits three developmental stages: epimastigote in the insect gut; trypomastigote, an infectious form in the mammalian blood stream; and an amastigote, a proliferative form in mammalian cells. In this paper we describe the results of continuous preliminary screening tests for trypanocidal activity against trypomastigotes as well as against epimastigotes in some Mexican plants.The edible fruit of Persea americana MILL. (Lauraceae), avocado, is grown throughout the tropics worldwides. The MeOH extract of seeds of Persea americana also showed moderate activity in the screening test. Herein we also describe the identification of the active constituents in seeds of P. americana. MATERIALS AND METHODS Plant Materials and Preparation of Their ExtractsPlant materials were mainly purchased at a medicinal plant market in Guadalajara, Jalisco, and collected in the fields. Identification of the plants was done by M. A. Martinez-Alfaro, one of the co-authors. The voucher specimens were deposited in the Herbarium of Jardín Botánico del Instituto de Biologia, Universidad Nacional Autonoma de Mexico.The plants examined are listed in Table 1 including those referred to in ref. 2. Dried and powdered materials were extracted with MeOH or MeOH-CH 2 Cl 2 at room temperature overnight. In the case of fresh materials, chopped materials were soaked in MeOH and filtered. The residue was extracted again with MeOH. The solvent was concentrated in vacuo to give each extract.Cultivation of T. cruzi The strain of T. cruzi used in this study and the cultivation method of epimastigotes were the same as those described in the previous paper.2) The trypomastigotes were harvested from the culture supernatant of rhesus monkey kidney (LLC-MK2) cells infected with T. cruzi as described in the previous paper.4,5) LLC-MK-2 cells were maintained in DMEM containing 10% FBS at 37°C under 5% CO 2 . After inoculation of trypomastigotes into LLC-MK2 cells, the medium was changed to DMEM containing 10% NCS.Instruments and Reagents The instruments and reagents used in this study are the same as those described in the preceding paper. 1)Trypanocidal Assay The detailed assay procedure against epimastigotes was described in the previous paper.2) The activity was expressed as the MC 100 value (mg/ml or mM), which was defined as the minimum concentration at which all the epimastigotes were terminated after incubation fo...

Oleanonic acid from Lippia lupulina (Verbenaceae) shows strong in vitro antileishmanial and antitrypanosomal activity

“…Our findings corroborate previously reported data on trypanocidal activity of Lippia species polar extracts (Abe et al 2005;Sülsen et al 2006). Sülsen et al (2006) reported in vitro activity of an organic and an aqueous extracts obtained from leaves of Lippia integrifolia against epimastigote forms of T. cruzi, with 34.5 and 71.2% inhibition, respectively, at 10 µg mL -1 .…”

“…Sülsen et al (2006) reported in vitro activity of an organic and an aqueous extracts obtained from leaves of Lippia integrifolia against epimastigote forms of T. cruzi, with 34.5 and 71.2% inhibition, respectively, at 10 µg mL -1 . On the other hand, Abe et al (2005) reported in vitro activity of a methanol extract of Lippia dulcis leaves against trypomastigote forms of T. cruzi, with MIC (minimum inhibitory concentration) between 125 and 250 µg mL -1 . Similar inhibitory activities have been observed in our experiments against epimastigote forms of T. cruzi, with IC 50 between 20 and 375 µg mL -1 (Table 1).…”

Screening of Latin American plants for antiparasitic activities against malaria, Chagas disease, and leishmaniasis

“…The antitrypanosomal activity of these species has not been reported previously in the literature except in the case of Annona muricata, which has been used in the folk medicine of Nicaragua for diarrhea (Coee & Anderson, 1996) and for fever in Colombia (Blair et al, 1991). Its antitrypanosomal activity against epimastigotes was reported previously (Abe et al, 2005). The 95% ethanol extract of seeds of Annona cherimola Mill.…”

Evaluación in vitro de la actividad anti Trypanosoma cruzi de aceites esenciales de diez plantas medicinales

“…Se ha reportado que el extracto de la hoja de B. dracunculifolia, a una concentración de 3 mg/mL, produjo 100% de lisis de formas tripomastigotes de T. cruzi (13) ; los extractos y fracciones de A. amazonicus mostraron lisis de las formas tripomasigotes de T. cruzi in vitro (14) ; otros investigadores también han demostrado el efecto tripanocida de diversos extractos vegetales (10,15,16) , así como de diversas estructuras terpénicas contra uno o todos los estadíos de T. cruzi (17)(18)(19)(20) . También han mostrado efecto tripanocida algunos alcaloides (21)(22)(23) , flavonoides (24)(25)(26) , lignanos (27) y artemisininas (28) .…”