Simvastatin attenuated sickness behavior and fever in a murine model of endotoxemia.

AIMS: During illnesses caused by infectious disease, a suite of brain-mediated responses called sickness syndrome occurs, triggering behavioral and physiological (fever) changes. Simvastatin is widely used as a lipid-lowering medication that has beneficial immunomodulatory properties. This study investigated the effects of simvastatin in a mouse model of sickness syndrome by systemic administration of lipopolysaccharide (LPS). MAIN METHODS: Male mice were pretreated with vehicle or simvastatin (40 mg/kg, p.o.) for 7 days and received LPS (200 µg/kg, i.p.) or sterile saline. We investigated the behavioral effects in male mice 2 h after LPS administration using tests screening for depressive-like behavior and locomotor activity alterations. Changes in body temperature were measured by biotelemetry probe preimplanted in the peritoneal cavity to evaluate the effect of simvastatin on the thermoregulatory response during immunological challenge. KEY FINDINGS: Pretreatment with simvastatin blunted most of the assessed parameters related to sickness syndrome, including depressive-like behavior and depressed locomotor activity, and attenuated LPS-induced fever. These data are consistent with simvastatin promoting alterations in peripheral febrigenic signaling (plasma levels of TNF-α, IL-1ß, and IL-10). SIGNIFICANCE: Our data provide further evidence of the capacity of simvastatin to attenuate sickness behavior and fever induced by immunological challenge through a mechanism related to changes in the profile of cytokine production.

Prenatal exposure to alcohol impairs social play behavior in adolescent male mice.

Prenatal ethanol exposure affects brain development and causes neural impairment, leading to both cognitive and behavioral consequences in the offspring. Therefore, the aim of this study was to investigate the impact of prenatal exposure to small amounts of alcohol on social play behavior in adolescent male offspring. Swiss mice were prenatally exposed to ethanol by feeding pregnant dams with a liquid diet containing 25% alcohol-derived calories during gestation (alcohol group). They were then compared to both pair-fed dams that received an isocaloric liquid diet containing 0% alcohol-derived calories (pair-fed group) and dams with ad libitum access to a liquid control diet (control group). Additionally, maternal behavior was evaluated in terms of neural activation indexed via c-fos expression in the prefrontal cortex. Although dams exposed to alcohol during pregnancy did not alter their maternal behavior, the offspring presented a decrease in their social play behavior compared with both control and pair-fed offspring. The decrease in social play behavior may be associated with a decrease in number of c-fos-positive cells in the prefrontal cortex. The exposure to small amounts of alcohol during intrauterine development causes both a deficit in social play behavior and a reduction in the neuronal activity seen in the prefrontal cortex.

P2 purinergic receptor antagonists disrupt maternal behavior in lactating rats.

The involvement of purinergic signaling in several brain functions has been recognized, but the modulation on maternal behavior by the purinergic system is not established, even though there are functional interactions between the purinergic and oxytocinergic systems. Therefore, the aim of our study was to investigate whether central administration of P2 receptor antagonists affected the maternal behavior of lactating rats and c-Fos immunoreactivity in the forebrain. On day 7 of lactation, female rats were treated with vehicle (5µL; i.c.v.), suramin (9.4-75.0µg/5µL; i.c.v.) or PPADS (9.4-75.0µg/5µL; i.c.v.) 30min before the experiment began. The maternal behavior was evaluated during the 30min following suramin or PPADS administration. In addition, c-Fos-positive nuclei were counted in the medial preoptic area (MPOA) and in the bed nucleus of the stria terminalis (BNST), and neurons that were double-labeled for c-Fos/OT were counted in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus of lactating rats. The results show that P2 receptor antagonists decreased maternal care and decreased neuronal activation in the MPOA and BNST and activation of oxytocinergic neurons in hypothalamic nuclei. Our results indicate that the purinergic system modulates maternal behavior and neuronal activation induced by suckling during lactation.

The Transient Receptor Potential Vanilloid 1 Antagonist Capsazepine Improves the Impaired Lung Mechanics during Endotoxemia.

Acute lung injury (ALI) caused by systemic inflammatory response remains a leading cause of morbidity and mortality in critically ill patients. Management of patients with sepsis is largely limited to supportive therapies, reflecting an incomplete understanding of the underlying pathophysiology. Furthermore, there have been limited advances in the treatments for ALI. In this study, lung function and a histological analysis were performed to evaluate the impact of transient receptor potential vanilloid-1 receptor (TRPV1) antagonist (capsazepine; CPZ) on the lipopolysaccharide (LPS)-induced lung injury in mice. For this, adult mice pre-treated with CPZ or vehicle received intraperitoneal injections of LPS or saline and 24 hr after, the mice were anaesthetized, and lung mechanics was evaluated. The LPS-challenged mice exhibited substantial mechanical impairment, characterized by increases in respiratory system resistance, respiratory system elastance, tissue damping and tissue elastance. The pre-treatment with CPZ prevented the increase in respiratory system resistance and decreased the increase in tissue damping during endotoxemia. In addition, mice pre-treated with CPZ had an attenuated lung injury evidenced by reduction on collapsed area of the lung parenchyma induced by LPS. This suggests that the TRPV1 antagonist capsazepine has a protective effect on lung mechanics in ALI during endotoxemia and that it may be a target for enhanced therapeutic efficacy in ALI.

Postnatal overnutrition in mice leads to impaired pulmonary mechanics in response to salbutamol.

Obesity increases the risk of respiratory disease, which is associated with airway hyperresponsiveness. Although the molecular underpinnings of this phenomenon are not well established, lung remodeling is known as an important factor in this process and could potentially explain compromised lung functions. In the present study, the obesity was induced by postnatal overnutrition in Swiss mice and we investigated the pulmonary mechanics after aerosolization of saline, methacholine, and salbutamol. The lungs were prepared for morphometric analysis. Obese animals showed bronchoconstriction in response to methacholine, as evidenced by airway and tissue resistance, tissue elastance, and hysteresivity. Salbutamol was effective at recovering the response only for airway resistance but not for tissue mechanics. We suggest that this impaired response in obese mice is related to collapsed alveolar, to inflammatory cells, and to elevated deposition collagen fibers in parenchymal tissue.

Anti-inflammatory and antipyretic effects of Sonchus oleraceus in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Sonchus oleraceus L. has been used to relieve headaches, general pain, hepatitis, infections, inflammation and rheumatism in Brazilian folk medicine. Nevertheless, scientific information regarding this species is scarce; there are no reports related to its possible anti-inflammatory effects. AIM OF THE STUDY: This study was aimed at evaluating the scientific basis for the traditional use of Sonchus oleraceus using in vivo inflammatory models. MATERIALS AND METHODS: Carrageenan-induced paw edema, peritonitis and febrile response induced by lipopolysaccharide tests, as well as fibrovascular tissue growth induced by s.c. cotton pellet implantation were used to investigate the anti-inflammatory activity of Sonchus oleraceus hydroethanolic extract (SoHE) in rats. RESULTS: The SoHE at test doses of 100-300 mg/kg p.o. clearly demonstrated anti-inflammatory effects by reduced paw edema induced by carragenan, inhibited leukocyte recruitment into the peritoneal cavity and reduced LPS-induced febrile response, and in the model of chronic inflammation using the cotton pellet-induced fibrovascular tissue growth in rats, the SoHE significantly inhibited the formation of granulomatous tissue. The extract administered at 300 mg/kg p.o. had a stronger anti-inflammatory effect than indomethacin (10mg/kg) or dexamethasone (1mg/kg). CONCLUSION: The hydroethanolic extract of Sonchus oleraceus markedly demonstrated anti-inflammatory action in rats, which supports previous claims of its traditional use.

Pyrostegia venusta attenuate the sickness behavior induced by lipopolysaccharide in mice.

AIM OF THE STUDY: Pyrostegia venusta (Ker.) Miers (Bignoniaceae) is native to the Brazilian Cerrado and popularly known as "cipó-de-são-joão." In traditional Brazilian medicine, the Pyrostegia venusta are used as a general tonic as well as a treatment for diarrhea, vitiligo, cough, and common diseases of the respiratory system related to infections, such as bronchitis, flu and cold. This study was conducted to evaluate the effects of a hydroethanolic extract of flowers of Pyrostegia venusta on sickness behaviors induced by lipopolysaccharide in mice. MATERIALS AND METHODS: To evaluate the effects of orally administered Pyrostegia venusta hydroethanolic extract (PvHE) on lipopolysaccharide-induced sickness behaviors, mice were submitted to the forced swim test (FST) and the open field test. RESULTS: Lipopolysaccharide (LPS, 100 µg/kg, i.p.) administration increased the time spent floating in the FST and depressed locomotor activity in the open field. Pretreatment with PvHE at test doses of 100 and 300 mg/kg, p.o. attenuated the behavioral changes induced by LPS in the FST and open field test. This effect was similar to pretreatment with dexamethasone (1 mg/kg), which is a steroidal drug that inhibits immune and inflammatory responses, including cytokine production. CONCLUSION: The extract of Pyrostegia venusta attenuated the depressive-like and exploratory behaviors induced by lipopolysaccharide. Thus, our results supported previous claims of the usefulness of these plants in traditional therapies and suggest that these plants may be useful in the treatment of disorders that induced sickness behavior, such as flu and cold.

Anti-inflammatory and antinociceptive effects of the hydroethanolic extract of the flowers of Pyrostegia venusta in mice

Pyrostegia venusta (Ker Gawl.) Miers, Bignoniaceae, is native to the Brazilian Cerrado and popularly known as "cipó-de-são-joão". In Brazilian folk medicine, the flowers of P. venusta are used as a general tonic and a treatment for diarrhea, vitiligo, cough, and common infections and inflammatory diseases of the respiratory system. Nevertheless, there are still no studies on its possible anti-inflammatory and antinociceptive effects. The P. venusta hydroethanolic extract (PvHE) was used to evaluate the anti-inflammatory and analgesic effects in carrageenan-induced paw edema, peritonitis induced by lipopolysaccharide, acetic acid-induced writhing, and formalin-induced paw-licking tests in Swiss male mice. PvHE at doses of 30-300 mg/kg p.o. demonstrated anti-inflammatory effect. PvHE reduced paw edema induced by carrageenan and inhibited leukocyte recruitment into the peritoneal cavity. The extracts showed antinociceptive activity in acetic acid-induced writhing and formalin tests. Our results showed that the PvHE demonstrated anti-inflammatory and antinociceptive action in mice. All the anti-inflammatory actions obtained are also suggested to due the presence of acacetin-7-O-β-glucopyranoside.