The hymenolepiosis by Hymenolepis nana is a major public health problem in developing countries, and the commercial drugs against this parasitosis are not enough effective. The combination of antiparasitic and antioxidant agents has improved the treatment of some parasitoses. Thus, the development of new cestocidal and antioxidant agents to treat the hymenolepiosis cases is important. In the present study, four hydroxy- and four dihydroxy-chalcones were synthesized using the catalyst boron trifluoride diethyl etherate (BF3•OEt2). The antioxidant activity and antiparasitic against H. nana of chalcones were tested, as well as the toxicity by the brine shrimp lethality bioassay and the method of Lorke. The antioxidant activity was measured by three radical scavenging assays: 2,2’-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). The hydroxyl substitution pattern (number and position), mainly in ring B, was responsible for the chalcone antiparasitic activity. At least one meta or para hydroxyl group in ring B was essential for activity of the synthetic chalcones against H. nana; The time taken for the parasite to die by the 3b and 3e chalcones (20 mg/mL) treatment was up to six times lower than the control drug Praziquantel. On the other hand, chalcones with catechol structure in ring B (3g and 3h) showed the highest antioxidant values. The toxicity evaluations suggests that synthetic hydroxychalcones with cestocidal (3b and 3e) and antioxidant (3g and 3h) activities are safe compounds and potential in vivo agents to treat this parasitosis.

ABSTRACT In Mexico, use of river water for households, agriculture and industry has adversely affected aquatic environment through chemical and microbial contamination. The aim of this study was to determine pesticide residues levels in water of rivers from central Sinaloa State, Northwestern Mexico. In samples obtained from July 2008 to June 2009 pesticides residues detected were lindane, heptachlor, endosulfan, dicloro difenil tricloroetano (DDT), diazinon, chlorpyrifos, permethrin, methyl parathion, cyromazine, ethion, carbofenothion, lambda cyhalotrine, pyrimicarb, malathion and aldrin. None exceeded water quality ecological criteria or those established by US Environmental Protection Agency. Comparatively low concentrations and frequencies suggest that pesticide contamination derived from runoffs toward river from contaminated soil particles and not from use of pesticides in intensive agriculture of region.

RESUMEN En México, el uso de agua de río para los hogares, la agricultura y la industria ha afectado negativamente al medio ambiente acuático a través de la contaminación química y microbiana. El objetivo de este estudio fue determinar los niveles de residuos de plaguicidas en agua de ríos del centro de Sinaloa, noroeste de México. En las muestras obtenidas de julio 2008 a junio de 2009, los residuos de plaguicidas detectados fueron lindano, heptacloro, endosulfán, dicloro difenil tricloroetano (DDT), diazinón, clorpirifos, permetrina, paratión metílico, ciromazina, etión, carbofenotión, lambda cialotrina, pirimicarb, malatión y aldrin. Ninguno superó los criterios ecológicos para la calidad del agua o de los establecidos por la Agencia de Protección Ambiental de Estados Unidos de América. Las concentraciones y frecuencias relativamente bajas sugieren que la contaminación por plaguicidas derivada de escurrimientos hacia el río de las partículas de suelo contaminado y no del uso de plaguicidas en la agricultura intensiva de la región.