Gizelda Maia Rêgo

Yield of advanced lines of peanut under rainfed conditions in northeast Brazil

Eleven upright and runner peanut advanced lines were conducted conditions in four states located in the northeast region aiming to evaluate their pod and seed yield. Assays were carried out in the agricultural year 2005/2007 in the states of Pernambuco (Araripina and Parnamirim), Sergipe (Lagarto), Bahia (Cruz das Almas and Caetite) and Paraiba (Campina Grande and Itabaiana). A completely randomized block experimental design with five replications was used with 13 treatments (8 upright and 5 runner genotypes). The analyzed variables were pod and seed yields. Individual and joint variance analysis were carried out and Tukey (p < 0.05) test was used to compare treatments. The BR 1 cultivar was adopted as a control. The highest pod and seed yields were obtained by LN-1B, with 2,450 and 1,665 kg ha-1, respectively, overcoming the mean of upright lines in 22 and 21%, and of the BR 1 cv. in 11 and 10%. As to runner lines, the pod and seed yields were not satisfactory under the conditions, however, LI-3, LI-5 and LI-1 overcame the group, with 1,722 and 1,154 kg ha-1, corresponding to 9.8 and 10% over general mean, respectively.

Effects of a Flavonoid-Rich Fraction on the Acquisition and Extinction of Fear Memory: Pharmacological and Molecular Approaches.

The effects of flavonoids have been correlated with their ability to modulate the glutamatergic, serotoninergic, and GABAergic neurotransmission; the major targets of these substances are N-methyl-D-aspartic acid receptor (NMDARs), serotonin type1A receptor (5-HT1ARs), and the gamma-aminobutyric acid type A receptors (GABAARs). Several studies showed that these receptors are involved in the acquisition and extinction of fear memory. This study assessed the effects of treatment prior to conditioning with a flavonoid-rich fraction from the stem bark of Erythrina falcata (FfB) on the acquisition and extinction of the conditioned suppression following pharmacological manipulations and on gene expression in the dorsal hippocampus (DH). Adult male Wistar rats were treated before conditioned fear with FfB, vehicle, an agonist or antagonist of the 5-HT1AR, GABAARs or the GluN2B-NMDAR or one of these antagonists before FfB treatment. The effects of these treatments on fear memory retrieval, extinction training and extinction retrieval were evaluated at 48, 72, and 98 h after conditioning, respectively. We found that activation of GABAARs and inactivation of GluN2B-NMDARs play important roles in the acquisition of lick response suppression. FfB reversed the effect of blocking GluN2B-NMDARs on the conditioned fear and induced the spontaneous recovery. Blocking the 5-HT1AR and the GluN2B-NMDAR before FfB treatment seemed to be associated with weakening of the spontaneous recovery. Expression of analysis of DH samples via qPCR showed that FfB treatment resulted in the overexpression of Htr1a, Grin2a, Gabra5, and Erk2 after the retention test and of Htr1a and Erk2 after the extinction retention test. Moreover, blocking the 5-HT1ARs and the GluN2B-NMDARs before FfB treatment resulted in reduced Htr1a and Grin2b expression after the retention test, but played a distinct role in Grin2a and Erk2 expression, according session evaluated. We show for the first time that the serotoninergic and glutamatergic receptors are important targets for the effect of FfB on the conditioned fear and spontaneous recovery, in which the ERK signaling pathway appears to be modulated. Further, these results provide important information regarding the role of the DH in conditioned suppression. Taken together, our data suggest that FfB represents a potential therapy for preventing or treating memory impairments.

Flavones-bound in benzodiazepine site on GABA A receptor: Concomitant anxiolytic-like and cognitive-enhancing effects produced by Isovitexin and 6-C-glycoside-Diosmetin

Abstract Increasing evidence suggests that flavones can modulate memory and anxiety‐like behaviour. However, these therapeutic effects are inconsistent and induce of adverse effects, which have been associated with interactions at the Benzodiazepine (BZ)‐binding site. To improve our understanding of flavone effects on memory and anxiety, we employed a plus‐maze discriminative avoidance task. Furthermore, we evaluated the potential of the compounds in modulating GABAA receptors via BZ‐binding site using molecular modelling studies. Adult male Wistar rats were treated 30 min before training session with Vicenin‐2 (0.1 and 0.25 mg/kg), Vitexin (0.1 and 0.25 mg/kg), Isovitexin (0.1 and 0.25 mg/kg) and 0.1 mg/kg 6‐C‐glycoside‐Diosmetin, vehicle and a GABAA receptor agonist. The analysis of the time spent in the non‐aversive vs aversive enclosed arms during the test session and percentage of time in the open arms within the training session revealed that treatment with Isovitexin and 6‐C‐glycoside‐Diosmetin had memory‐enhancing and anxiolytic‐like effects (P < 0.001). In contrast, treatment with a higher dose of Diazepam impaired short‐and long‐term memory when it alleviated anxiety level. Docking studies revealed that flavones docked in a very similar way to that observed to the Diazepam, except by a lack of interaction in residue &agr;1His101 in the BZ‐binding site on GABAA receptors, which may be related to memory‐enhancing effect. The occurrence of the &agr;1His101 interaction could justify the memory‐impairing observed following Diazepam treatment. These findings provide the first evidence that Isovitexin and 6‐C‐glycoside‐Diosmetin could exert their memory‐enhancing and anxiolytic‐like effects via GABAA receptor modulation, which likely occurs via their benzodiazepine‐binding site.