Mariangela S. Azevedo

Ethanolic extract from bulbs of Cipura paludosa reduced long-lasting learning and memory deficits induced by prenatal methylmercury exposure in rats.

Previous studies from our group have indicated important biological properties of the ethanolic extract (EE) and isolated compounds from the bulbs of Cipura paludosa (Iridaceae), a native plant widely distributed in northern Brazil. In the present study, the effects of chronic treatment with the EE on the memory of adult rats exposed to methylmercury (MeHg) during early development were assessed. Pregnant rats were treated by gavage with a single dose of MeHg (8 mg/kg) on gestational day 15, the developmental stage critical for cortical neuron proliferation. Adult offspring were administered orally with the EE of C. paludosa (1, 10 or 100mg/kg) over 14 consecutive days. EE improved short-term social memory in a specific manner and facilitated the step-down inhibitory avoidance of short- and long-term memory. MeHg exposure induced pronounced long-lasting impairments in social recognition memory that were improved by EE. Moreover, EE significantly increased the step-down latencies specifically during the short-term session in prenatal MeHg-exposed rats. These results demonstrate that EE reduced the long-lasting short-term learning and memory deficits induced by MeHg exposure. These findings may encourage further studies evaluating the cognitive enhancing properties of C. paludosa and its components on neuropathological conditions associated with exposure to environmental contaminants.

Cipura paludosa attenuates long-term behavioral deficits in rats exposed to methylmercury during early development.

In the present study, we evaluated the effects of the ethanolic extract (EE) of Cipura paludosa on locomotor, and anxiety- and depression-like behaviors of adult rats exposed to MeHg during early development. Additionally, the antioxidant enzymes catalase (CAT) and selenium-glutathione peroxidase (Se-GPx) were measured in cortical, hippocampal, and cerebellar tissues. Pregnant Wistar rats were treated by gavage with a single dose of MeHg (8 mg/kg) on gestational day 15, the developmental stage critical for cortical neuron proliferation. Moreover, prenatal MeHg exposure inhibited CAT and Se-GPx in the cortex and cerebellum. Chronic treatment with the EE of C. paludosa attenuated these emotional and antioxidant deficits induced by prenatal MeHg toxic exposure. This study provides novel evidence that developmental exposure to MeHg can affect not only cognitive functions but also locomotor, and anxiety- and depression-like behaviors.

Contaminação de aqüífero por hidrocarbonetos: estudo de caso na Vila Tupi, Porto Velho - Rondônia

Underground storage tanks (UST) are widely used in the Porto Velho area. A large number of these USTs are in bad condition due to corrosion processes causing groundwater contamination. A large number of these leaking underground fuel tanks (LUFT) are in urban areas but due to the lack of water quality monitoring, they are only detected when there is a high contamination level. This study identified petroleum hydrocarbons, derived from a LUFT, by a silica gel/petroleum ether partitioning gravimetric method and by gas chromatographic analysis of samples collected in wells dug in a gas station and in houses in the aforementioned neighborhood.

Effects of Ethanolic Extract and Naphthoquinones Obtained from the Bulbs of Cipura paludosa on Short-Term and Long-Term Memory: Involvement of Adenosine A1 and A2A Receptors

Previous studies from our group have indicated important biological properties of the ethanolic extract and isolated compounds from the bulbs of Cipura paludosa (Iridaceae), a native plant widely distributed in northern Brazil, including antioxidant, neuroprotective and anti‐nociceptive activities. In the present study, the effects of the ethanolic extract and its two naphthoquinones (eleutherine and isoeleutherine) on the short‐ and long‐term memory of adult rodents were assessed in social recognition and inhibitory avoidance tasks. Acute pre‐training oral administration of the ethanolic extract improved the short‐term social memory in rats as well as facilitated the step‐down inhibitory avoidance short‐ and long‐term memory in mice. Moreover, the co‐administration of ‘non‐effective’ doses of the extract of Cipura paludosa and the adenosine receptor antagonists caffeine (non‐selective), DPCPX (adenosine A1 receptor antagonist) and ZM241385 (adenosine A2A receptor antagonist) improved the social recognition memory of rats. In the inhibitory avoidance task, the co‐administration of sub‐effective doses of the extract with caffeine or ZM241385, but not with DPCPX, improved the short‐ and long‐term memory of mice. Finally, the acute oral administration of eleutherine and isoeleutherine facilitated the inhibitory avoidance short‐ and long‐term memory in mice. These results demonstrate for the first time the cognitive‐enhancing properties of the extract and isolated compounds from the bulbs of Cipura paludosa in rodents and suggest a possible involvement of adenosine A1 and A2A receptors in these effects.