Search

Introduction: In tropical and developing countries, pathogenic protozoa are a major public health problem. Objective: The main objective of this study was the evaluation of ethanol extracts of Curcuma longa and Berberis vulgaris, as well as their main components curcumin (Cur) and berberine (Ber) in non-encapsulated form and encapsulated into polymeric nanoparticles (NPs) on Entamoeba histolytica and Trichomonas vaginalis trophozoites as well as to evaluate the hemolytic activity. Additionally, we studied the morphology of the NPs, average particle size, polydispersity index (PDI), and encapsulation percentages (%EE) of the formulations. Methods: For this purpose, the activity of the encapsulated and non-encapsulated treatments against E. histolytica and T. vaginalis was evaluated by the microassay technique (in-vitro). In addition, the cytotoxic capacity was determined by the hemolysis technique in healthy erythrocytes. The size and morphology of the NPs were determined by photon correlation spectroscopy and scanning electron microscopy (SEM). Results: Phytochemical analysis of the extracts showed that C. longa had mainly tannins, phenols and flavonoids, and B. vulgaris alkaloids. The NPs were significantly (P < 0.001) more effective compared to their non-encapsulated counterparts, but CurNPs and BerNPs were the most efficient treatments. CurNPs showed IC50 values (μg/mL) of 9.48 and 4.25, against E. histolytica and T. vaginalis respectively, and BerNPs 0.24 and 0.71. The respective particle sizes and encapsulation percentages for CurNPs and BerNPs were 66.5 and 73.4 nm, 83.59 and 76.48 %, respectively. SEM shows that NPs had a spherical morphology. Finally, we analyzed whether ethanolic extracts and NPs induced hemolytic activity and found that significantly NPs reduced hemolysis compared to the non-encapsulated extracts. Conclusions: Therefore, these findings suggest that the use of NPs represent a valuable and novel source of administration of bioactive compounds for the therapeutic treatment of diseases caused by protozoa of clinical interest since they potentiate the amebicidal and trichomonicidal activity of the administered products without significant hemolytic activity. Introducción: En los países tropicales y en desarrollo, los protozoos patógenos constituyen un importante problema de salud pública. Objetivo: El objetivo principal de este estudio fue la evaluación de los extractos etanólicos de Curcuma longa y Berberis vulgaris, y de sus componentes principales curcumina (Cur) y berberina (Ber) en forma no encapsulada y encapsulada en nanopartículas poliméricas (NPs) sobre los trofozoítos de Entamoeba histolytica y Trichomonas vaginalis, así como evaluar la actividad hemolítica. Además, se estudió la morfología de las NPs, el tamaño medio de las partículas, el índice de polidispersidad (PDI) y los porcentajes de encapsulación (%EE) de las formulaciones. Métodos: Para ello, se evaluó la actividad de los tratamientos encapsulados y no encapsulados frente a E. histolytica y T. vaginalis, mediante la técnica del microensayo (in-vitro). Además, se determinó la capacidad citotóxica mediante la técnica de hemólisis en eritrocitos sanos. El tamaño y la morfología de las NPs se determinó mediante espectroscopia de correlación fotónica y mediante microscopia electrónica de barrido (SEM). Resultados: El análisis fitoquímico de los extractos mostró que C. longa tenía principalmente taninos, fenoles y flavonoides, y B. vulgaris alcaloides. Las NPs fueron significativamente (P < 0.001) más eficaces en comparación con sus homólogas no encapsuladas, sin embargo, CurNPs y las BerNPs fueron los tratamientos más eficaces. CurNPs mostró valores de IC50 (μg/mL) de 9.48 y 4.25, contra E. histolytica y T. vaginalis respectivamente, y las BerNPs 0.24 y 0.71. Los tamaños de partícula respectivos y porcentajes de encapsulación para las CurNPs y BerNPs fueron de 66.5 y 73.4 nm, y de 83.59 y 76.48 %, respectivamente. La SEM muestra que las NPs tenían una morfología esférica. Finalmente, se analizó si los extractos etanólicos y las NPs inducían actividad hemolítica y encontramos que significativamente las NPs reducían la hemólisis en comparación con los extractos no encapsulados. Conclusiones: Estos hallazgos sugieren que el uso de las NPs representa una valiosa y novedosa fuente de administración de compuestos bioactivos para el tratamiento terapéutico de enfermedades causadas por protozoos de interés clínico ya que potencian la actividad amebicida y tricomonicida de los productos administrados sin actividad hemolítica significativa.

Entamoeba histolytica (protozoan, family Endomoebidae) is the cause of amoebiasis, a disease related to high morbidity and mortality. Nowadays, this illness is considered a significant public health issue in developing countries. In addition, parasite resistance to conventional medicinal treatment has increased in recent years. Traditional medicine around the world represents a valuable source of alternative treatment for many parasite diseases. In a previous paper, we communicated about the antiprotozoal activity in vitro of the methanolic (MeOH) extract of Ruta chalepensis (Rutaceae) against E. histolytica. The plant is extensively employed in Mexican traditional medicine. The following workup of the MeOH extract of R. chalepensis afforded the furocoumarins rutamarin (1) and chalepin (2), which showed high antiprotozoal activity on Entamoeba histolytica trophozoites employing in vitro tests (IC50 values of 6.52 and 28.95 µg/mL, respectively). Therefore, we offer a full scientific report about the bioguided isolation and the amebicide activity of chalepin and rutamarin.

Amoebiasis caused by Entamoeba histolytica is associated with high morbidity and mortality is becoming a major public health problem worldwide, especially in developing countries. Because of the side-effects and the resistance that pathogenic protozoa build against the standard antiparasitic drugs, e.g., metronidazole, much recent attention has been paid to plants used in traditional medicine around the world in order to find new antiprotozoal agents. We collected 32 plants used in Northeast Mexican traditional medicine and the methanolic extracts of these species were screened for antiprotozoal activity against E. histolytica trophozoites using in vitro tests. Only 18 extracts showed a significant inhibiting activity and among them six plant extracts showed more than 80% growth inhibition against E. histolytica at a concentration of 150 µg/mL and the IC50 values of these extracts were determined. Lippia graveolens Kunth and Ruta chalepensis Pers. showed the more significant antiprotozoal activity (91.54% and 90.50% growth inhibition at a concentration of 150 µg/mL with IC50 values of 59.14 and 60.07 µg/mL, respectively). Bioassay-guided fractionation of the methanolic extracts from these two plants afforded carvacrol (1) and chalepensin (2), respectively, as bioactive compounds with antiprotozoal activity.