Shrimps can be used as indicators of the quality of aquatic systems exposed to a variety of pollutants. Chlorpyrifos is one of the most common pesticides found in environmental samples. In order to evaluate the effects of chlorpyrifos, adult organisms of Litopenaeus vannamei were exposed to two sublethal concentrations of the pesticide (0.7 and 1.3 μg/L) for four days. The LC 50 (96-hours) value was determined and Lipid oxidation levels (LPO) and the activities of catalase (CAT), glutathion peroxidase (GPx), glutathion-S-transferase (GST) were assessed on the muscle, hepatopancreas and gills from the exposed organisms. In addition, inhibition of acetylcholinesterase (AChE) was determined in the brain. LC 50 (96hours) was 2.10 μg/L of chlorpyrifos. Catalase activity and LPO were elevated in the three tissues, whereas a decrease of AChE activities in the brain and an increase of GST activity in the hepatopancreas were observed.

The essential oil from the fresh leaves of Kyllinga pumila (Michx) was obtained by hydrodistillation and characterized by gas chromatography-mass spectrometry (GC-MS). Twenty-eight volatile compounds were identified, major constituents of the oil were Methyl E,E-10,11-epoxyfarnesoate (43.8%), β-elemene (12.5%), Z-caryophyllene (11.3%), germacrene D (7.1%) and E-caryophyllene (5.6%). Repellent and fumigant activities of the oil against Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), were done using the area preference method. Additionally, we studied their antioxidant and phytotoxic effects. Essential oils exhibited a dose-dependent repellent activity, with values 90% at the applied concentration (0.01%), for both two and four hour's exposure. Essential oil from K. pumila showed 92% mortality at 500 μL L-1 air against T. castaneum on 24 hours of exposure. The value LC 50 was 153.4 μL L-1. With moderate selective phytotoxic effects on L. perenne root growth (±70% inhibition). Kyllinga pumila shows high antioxidant potential (91.5%), an effect that is comparable with ascorbic acid (92.9%) used as a standard. The results indicated that K. pumila essential oil could be a promising alternative to new natural antioxidants, repellents, and biocides.

No abstract

No abstract

The objectives of this work were the study of the volatile chemical composition of essential oils (EO’s) from Swinglea glutinosa, as well as to evaluate their antioxidant, repellent and fumigant properties. The EO was obtained by hydrodistillation from the peel of the fruit, gathered in the city of Cartagena, Bolívar (Colombia). The volatile composition was analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The major compounds found in S. glutinosa were germacrene D (4.8%), limonene (5.2%), a-terpineol (6.5%), b-pinene (8.5%), nerolidyl acetate (9.8%), and trans-nerolidol (34.6%). S. glutinosa showed antioxidant potential (85.8%) (IC50=142.49 µg mL-1). The EO deployed repellent activity against the Tribolium castaneum weevil at a concentration of 15.73 nL cm-1 at 2 hours of exposure (72%), while the result for the commercial repellent was 50% at the same concentration. EO from S. glutinosa displayed the best fumigant activity with LC50 of 153.4 μg mL-1 air. The essential oil from S. glutinosa can be considerated as a natural source of biocides and antioxidants.