Abstract Previous pre-clinical studies demonstrated that a valepotriates enriched fraction from Valeriana glechomifolia F.G. Mey., Caprifoliaceae, was effective against lipopolysaccharide from Escherichia coli (LPS)-induced sickness behavior as well as significantly decreased the cortical expression of pro inflammatory cytokines interleukin-1β and tumor necrosis factor-α. Other studies revealed anti-inflammatory properties of V. wallichii and V. amurensis. These findings open up new perspectives for Valeriana genus pharmacology, once it has been commonly associated to sedative and anxiolytic properties. The aim of this study was to investigate the antichemotactic, antinociptive and anti-inflammatory activities of a valepotriate-enriched fraction obtained from aerial and subterranean parts of V. glechomifolia submitted to supercritical CO2 extraction. The biological activities were assessed by means of formalin test in CF1 mice and Wistar rat's leukocytes migration assay (modified Boyden chamber method). Valepotriate-enriched fraction (1, 10 and 30 mg/kg, p.o.) inhibited the nociceptive behavior in the late phase of the formalin test in a dose dependent manner. The effect of the valepotriate-enriched fraction highest dose was comparable with that of diclofenac 50 mg/kg (p.o.). Valepotriate-enriched fraction (0.1–1 µg/ml) inhibited the leukocyte migration induced by lipopolysaccharide from Escherichia coli in a concentration dependent manner. This antichemotatic effect was comparable with that of indomethacin (0.1–1 µg/ml) and better than diclofenac (1 µg/ml) effect. This study demonstrated for the first time that a valepotriate-enriched fraction obtained from V. glechomifolia display a peripheral anti-inflammatory like activity.

ABSTRACT Immobility time in the forced swimming has been described as analogous to emotional blunting or apathy and has been used for characterizing schizophrenia animal models. Several clinical studies support the use of NMDA receptor antagonists to model schizophrenia in rodents. Some works describe the effects of ketamine on immobility behavior but there is variability in the experimental design used leading to controversial results. In this study, we evaluated the effects of repeated administration of ketamine sub-anesthetic doses in forced swimming, locomotion in response to novelty and novel object recognition, aiming a broader evaluation of the usefulness of this experimental approach for modeling schizophrenia in mice. Ketamine (30 mg/kg/day i.p. for 14 days) induced a not persistent decrease in immobility time, detected 24h but not 72h after treatment. This same administration protocol induced a deficit in novel object recognition. No change was observed in mice locomotion. Our results confirm that repeated administration of sub-anesthetic doses of ketamine is useful in modeling schizophrenia-related behavioral changes in mice. However, the immobility time during forced swimming does not seem to be a good endpoint to evaluate the modeling of negative symptoms in NMDAR antagonist animal models of schizophrenia.

ABSTRACT Uliginosin B, a phloroglucinol isolated from Hypericum polyanthemum Klotzsch ex Reichardt, Hypericaceae, has antidepressant-like effect in the forced swimming test in rodents and inhibits monoamines neuronal reuptake without binding to their neuronal carriers. Studies showed the involvement of Na+,K+-ATPase brain activity in depressive disorders, as well as the dependence of neuronal monoamine transport from Na+ gradient generated by Na+,K+-ATPase. This study aimed at evaluating the effect of uliginosin B on Na+,K+-ATPase activity in mice cerebral cortex and hippocampus (1 and 3 h after the last administration) as well as the influence of veratrine, a Na+ channel opener, on the antidepressant-like effect of uliginosin B. Mice were treated (p.o.) with uliginosin B single (10 mg/kg) or repeated doses (10 mg/kg/day, 3 days). Acute administration reduced the immobility in the forced swimming test and tail suspension test and increased Na+,K+-ATPase activity in cerebral cortex 1 h after treating, whereas the repeated treatment induced the antidepressant-like effect and increased the Na+,K+-ATPase activity at both times evaluated. None treatment affected the hippocampus enzyme activity. Veratrine pretreatment prevented uliginosin B antidepressant-like effect in the forced swimming test, suggesting the involvement of Na+ balance regulation on this effect. Altogether, these data indicate that uliginosin B reduces the monoamine uptake by altering Na+ gradient.