Levels of persistent organic pollutants in cane toads (Rhinella marina) differ among sites with varying industrial and agricultural activities.

In this study, we captured cane toads (Rhinella marina) in four sites located in different regions affected by anthropogenic activities in Mexico. Subsequently we analyzed liver tissue for the presence of organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) The levels of these POPs in the toads' livers ranged from 863.2 to 3109.6 ng/g of lipid weight across all sites. A multivariate statistical analysis highlighted two sites with the highest POPs levels, with the most polluted site displaying a high level of PCBs, suggesting influence of industrial activities. The second most polluted site displayed significant amounts of OCs, linking this location to agricultural activity. Additionally, we found pesticide metabolites and isomers that allowed us to distinguish past and recent exposure events. Our observations indicate that R. marina is suitable bioindicator of sites impacted by anthropogenic activities.

Antihyperalgesia induced by Heliopsis longipes extract.

Heliopsis longipes is an herbaceous plant found in Mexico. Heliopsis longipes is traditionally used for its analgesic and anesthetic properties. Plant extracts may represent a therapeutic advantage for the clinical treatment of pain. Therefore, the main objective of this study was to determine the possible antihyperalgesic effect produced by the Heliopsis longipes ethanolic extract (HLEE) in the Hargreaves model of thermal hyperalgesia in the mouse. HLEE was administrated systemically to mice and the antihyperalgesic effect was evaluated using the thermal hyperalgesia test. Oral Administration of HLEE produced a dose-dependent antihyperalgesic effect. Previously, it was reported that Heliopsis longipes extract was able to release GABA in mice temporal cortex slices. Therefore, it is likely that the antihyperalgesic effect observed in our study could result from GABA liberation and its inhibition of excessive excitation of nociceptive circuits in the thalamus and cortex evoked by tissue injury. Our results suggest that HLEE may represent a therapeutic advantage for the clinical treatment of inflammatory pain.