Diene Valepotriates from <i>Valeriana glechomifolia</i> Prevent Lipopolysaccharide-Induced Sickness and Depressive-Like Behavior in Mice

Müller, Liz G.; Borsoi, Milene; Stolz, Eveline D.; Herzfeldt, Vivian; Viana, Alice F.; Ravazzolo, Ana Paula; Rates, Stela Maris K.

doi:https://doi.org/10.1155/2015/145914

Evidence-Based Complementary and Alternative Medicine

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Research Article | Open Access

Volume 2015 | Article ID 145914 | https://doi.org/10.1155/2015/145914

Diene Valepotriates from Valeriana glechomifolia Prevent Lipopolysaccharide-Induced Sickness and Depressive-Like Behavior in Mice

Liz G. Müller,¹Milene Borsoi,²Eveline D. Stolz,¹Vivian Herzfeldt,¹Alice F. Viana,¹Ana Paula Ravazzolo,³and Stela Maris K. Rates¹

Academic Editor: David Mischoulon

Received10 Mar 2015

Revised24 May 2015

Accepted26 May 2015

Published11 Jun 2015

Abstract

Valeriana glechomifolia, a native species from southern Brazil, presents antidepressant-like activity and diene valepotriates (VAL) contribute to the pharmacological properties of the genus. It is known that depression can develop on an inflammation background in vulnerable patients and antidepressants present anti-inflammatory properties. We investigated the effects of VAL (10 mg/kg, p.o.) on sickness and depressive-like behaviors as well as proinflammatory cytokines (IL-1β and TNF-α) and BDNF expression in the cortex of mice exposed to a 5 min swimming session (as a stressful stimulus) 30 min before the E. coli LPS injection (600 µg/kg, i.p.). The forced swim + LPS induced sickness and depressive-like behaviors, increased the cortical expression of IL-1β and TNF-α, and decreased BDNF expression. VAL was orally administered to mice 1 h before (pretreatment) or 5 h after (posttreatment) E. coli LPS injection. The pretreatment with VAL restored the behavioral alterations and the expression of cortical proinflammatory cytokines in LPS-injected animals but had no effects on BDNF expression, while the posttreatment rescued only behavioral alterations. Our results demonstrate for the first time the positive effects of VAL in an experimental model of depression associated with inflammation, providing new data on the range of action of these molecules.

1. Introduction

Major depressive disorder (MDD) is a recurrent and incapacitating mood disorder being related to high mortality and morbidity [1]. Despite the fact that the accepted “monoamine hypothesis” contributed to the comprehension about the neurobiology of mood disorders, the pathogenesis of MDD has not been completely elucidated yet [2]. Thus, the identification of novel biological targets and pathways that may play a role in MDD pathophysiology is required.

In this regard, several studies have been pointing to the association of the immune system activation with MDD [3, 4]. Of note, depressed patients display elevated plasma levels of proinflammatory cytokines such as interleukin- (IL-) 1, IL-6, and tumor necrosis factor-alpha (TNF-) [2, 5–7] as well as increased expression of proinflammatory cytokines in frontal cortex [8]. Also, some studies showed that the association of anti-inflammatories to conventional antidepressants increased the efficacy of these drugs [9–11].

Preclinical studies have been demonstrating that systemic administration of Escherichia coli lipopolysaccharide (LPS) to rodents results in behavioral time-dependent changes related to increased peripheral and central proinflammatory cytokines production [3, 12, 13]. It is known that LPS-injected rodents present behavioral signs of sickness (such as decreased locomotor and exploratory activities) that are followed by depressive-like behavior [3]. The switch from sickness to depression occurs after the activation of indoleamine 2,3-dioxygenase, which culminates in decreased central serotonin levels [14].

Recently, evidences have suggested the involvement of disrupted neuroplasticity in MDD pathophysiology [3, 15]. Furthermore, hippocampal neurogenesis and neurotrophins (especially the brain derived neurotrophic factor, BDNF) expression are thought to be necessary for the behavioral effects of antidepressants [16, 17]. In addition, some authors demonstrated that intraperitoneal administration of LPS to rodents is correlated with decreased BDNF levels in the hippocampus and cortex [13, 18, 19].

Noteworthy, the administration of antidepressants [18, 20] to animals subjected to the above mentioned model of depression prevents the development of sickness and depressive-like behavior. Interestingly, the antidepressant potential of anti-inflammatory drugs has been demonstrated in the forced swimming test in models of depression related to stress in rats [21]. Also, the anti-inflammatory properties of natural products in LPS-injected rodents have been shown by several studies [22–24].

In line with these observations, some studies have been pointing to the anti-inflammatory properties of the Valeriana genus, which is widely known by its sedative and anxiolytic properties [25], representing a new approach to the therapeutic use of the genus. The anti-inflammatory potential of species such as V. wallichii [26], V. amurensis [27], and V. officinalis, which prevents the sickness and depressive-like behavior in rats submitted to a model of depression related to inflammation [28], has been demonstrated. Furthermore, some authors have already shown the antidepressant potential of those species [25, 29, 30].

In this sense, our research group has been investigating the pharmacological properties of V. glechomifolia Meyer, one species native to southern Brazil that is especially enriched in valepotriates [31]. Valepotriates are nonglycosylated carbocyclic iridoids, comprising a family of terpenes [32] that contribute to the pharmacological properties of the genus [33–36]. The antidepressant potential of diene valepotriates was demonstrated by our research group as well as its action on noradrenergic and dopaminergic neurotransmission [37], suggesting a dual-action mechanism distinct of most of the conventional antidepressants.

Considering the above mentioned data, in the present study we investigated the effects of a diene valepotriates fraction (VAL) obtained from V. glechomifolia on sickness and depression-like behavior triggered by intraperitoneal administration of E. coli LPS, in mice previously submitted to a forced swimming session as a stressful stimulus [13]. We also investigated VAL effects on the cortical expression of proinflammatory cytokines (IL-1 and TNF-) and BDNF. This experimental protocol was chosen on the basis of the concept that internal and external stressors interact, resulting in an illness state that causes an allostatic overload [38, 39].

2. Materials and Methods

2.1. Drugs and Chemicals

For the extract characterization, grade HPLC acetonitrile and methanol were purchased from Merck (Germany). For the behavioral experiments, the following drugs were used: imipramine from Henrifarma (Porto Alegre, Brazil) and lipopolysaccharide (LPS) from Escherichia coli serotype 0111:B4 from Sigma Chemical Co. (St. Louis, MO, USA). All chemicals were obtained in the highest grade.

2.2. Plant Material

Valeriana glechomifolia above-ground and below-ground material was collected during its flowering stage in the region of São José dos Ausentes, state of Rio Grande do Sul, Brazil. The collection was authorized by SISBIO-IBAMA (protocol n° 29495-1). The identification was performed by Dr. M. Sobral (Universidade Federal de São João del-Rei, state of Minas Gerais, Brazil) and a voucher specimen (Sobral, 7733) was deposited in the Herbarium of the Universidade Federal do Rio Grande do Sul (ICN), Brazil.

2.3. VAL Extraction and Characterization by HPLC

To obtain the VAL fraction, 100 g (dry weight) of dried and powdered plant material was submitted to supercritical CO₂ (SCCO₂) extraction, using a Pilot Equipment as described elsewhere [37, 40, 41]. The conditions of the extraction were 40°C, 90 bar, SCCO₂ flow rate through the extraction vessel: kg s⁻¹. The SCCO₂ extraction recovery was 2.96 g%.

The VAL fraction was dissolved in HPLC grade methanol and filtered (0.22 m pore size, Merck) before the analysis by HPLC according to a method previously described [37, 41, 42], using Shimadzu HPLC system and Waters Nova-Pack C18 column (4 mm, 3.9 × 150 mm i.d. with Waters Nova-Pack C-18 guard column, 60 Å, 3.9 × 20 mm). The isocratic mobile phase consisted of acetonitrile and water (50 : 50 v/v); flow rate of 1 mL/min; UV detection at 254 nm. All diene valepotriates were quantified in terms of mg of valtrate equivalent/g extract. The VAL fraction was suspended in saline with 1% of polysorbate 80 (vehicle) prior to use.

2.4. Animals

Male CF1 mice (25–30 g) were from Fundação Estadual de Produção e Pesquisa em Saúde, Rio Grande do Sul, Brazil. Animals were housed in plastic cages (17 × 28 × 13 cm) at 23° ± 1°C under a 12-hour light/dark cycle, with food and water provided ad libitum. Experiments were approved by Animal Care Local Ethical Committee (CEUA-UFRGS; protocol n° 22648) and were conducted in accordance with Brazilian law [43–45] and European Communities Council Directive of 24 November 1986 (86/609/EEC).

2.5. Experimental Design

The experimental protocol was carried out according to Viana and coworkers [13] with minor modifications. The animals (n = 8–11 mice/group) were submitted to a prestressful stimulus (6 min forced swimming session, water at 23 ± 1°C) 30 min before receiving LPS from E. coli (600 g/kg, i.p.) or vehicle (0.9% NaCl solution, 10 mL/kg, i.p.). The animals were submitted to behavioral tests 6 h and 24 h after the LPS injection.

In order to verify the effects of VAL on forced swim + LPS-induced behavioral and neurochemical alterations, independent groups of mice were treated with VAL (10 mg/kg, p.o.) or vehicle (0.9% NaCl solution with 1% of polysorbate 80) 1 h before the forced swimming session (pretreatment protocol, in order to evaluate their preventive potential) or 5 h after LPS injection (posttreatment protocol, in order to evaluate their therapeutic potential). The antidepressant imipramine (IMI) was used as a positive control (20 mg/kg, p.o.). The doses of VAL and IMI were determined on the basis of previous studies from our group [37]. Mice were sacrificed by cervical dislocation 1 h after the final behavioral test for quantitative reverse transcription polymerase chain reaction (RT-qPCR) analysis. A naïve group was included for RT-qPCR analysis. A schematic overview of the experimental design is shown in Figure 1.

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(b)

2.6. Behavioral Paradigms

2.6.1. Open Field Test (OFT)

To assess the effects of the forced swimming session + LPS treatment (as well as the effects of VAL and IMI before and after treatment) on the locomotor activity, mice were evaluated in the OFT, 6 or 24 h after LPS administration. Animals were individually placed in an acrylic box (40 × 30 × 30 cm), with the floor being divided into 24 equal squares. The number of squares crossed with the four paws (crossing) was recorded in a 6 min session.

2.6.2. Tail Suspension Test (TST)

Mice depression-like behavior following the forced swimming session + LPS treatment (as well as the effects of VAL and IMI before and after treatment) was evaluated by using the TST as previously described by Steru and coworkers [46] with minor modifications. Immediately after being submitted to the OFT (6 or 24 h after LPS injection), the animals were suspended by the tail 60 cm above the floor using adhesive tape (1 cm from the tip of the end). The time during which mice remained immobile was recorded (in seconds) during the last 4 min of a total 6 min session [47].

2.7. Quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) for Quantification of IL-1β, TNF-α, and BDNF mRNA Expression

Mice cortices were collected and immediately immersed in liquid nitrogen and stored at −80°C until use. Total RNA was extracted using TRIzol Reagent (Invitrogen), according to the manufacturer’s instructions. The concentration and purity of the RNA were assessed at 260 nm and 260/280 nm absorbance measurements, respectively. Also, its integrity was evaluated by using agarose gel electrophoresis stained with ethidium bromide. Complementary DNA (cDNA) was synthesized from 2 g of total RNA using a High Capacity cDNA Transcription kit (Applied Biosystems Inc., Foster City, CA) in a 10 L reaction. After obtaining the cDNA, samples were stored at −20°C. IL-1, TNF-, and BDNF expression was carried out through fluorescence-based real-time PCR, by amplifying 100 ng of cDNA (in duplicates) using TaqMan-based chemistry with specific primers, FAM-labeled probes (Assays-by-Demand, Life Technologies) for mouse IL-1 (#Mm00434228_m1), TNF- (#Mm00443260_g1), and BDNF (#Mm00432069_m1) and VIC-labeled glyceraldehyde-3-phosphate dehydrogenase (GAPDH) (Assays-by-Demand, Life Technologies, #Mm99999915_g1) as the endogenous control for normalization. Amplifications were carried out in a thermal-cycler (StepOne Plus, Applied Biosystems) for 70 cycles; the fluorescence was collected at each amplification cycle and the data were analyzed using the method for relative quantification. Expression of the target genes was calibrated against conditions found in naïve mice.

2.8. Statistical Analysis

Data from behavioral experiments and RT-qPCR were analyzed by two- or one-way ANOVA, respectively, followed by Student-Newman-Keuls test when appropriate. The statistical procedures were performed using the Sigma Stat software 2.03 (Jandel Scientific Corporation). The level for statistical significance was set as p < 0.05. The results are given as mean ± S.E.M.

3. Results

3.1. VAL Fraction Characterization

The characterization of the VAL fraction by HPLC revealed that valtrate was the diene valepotriate present in larger quantity (643 ± 56 mg/g), followed by acevaltrate (172 ± 34 mg/g), 1--acevaltrate (87 ± 9 mg/g), 1--aceacevaltrate (39 ± 5 mg/g), and isovaltrate (37 ± 6 mg/g). Results are expressed in mean ± S.D. HPLC chromatograms of the VAL fraction have already been published [41]. The chemical structures of each diene valepotriate are presented in Figure 2.

3.2. Effects of VAL and IMI on Forced Swim + LPS-Induced Sickness and Depression-Like Behavior

The effects of VAL or IMI pretreatment protocol on forced swim + LPS-induced behavioral alterations are presented in Figure 3. The forced swim + LPS administration elicited a significant (p < 0.001) decrease in mice locomotor activity at 6 h after the injection (Figure 3(a)), which was prevented by mice pretreatment with VAL and IMI (1,59) = 17.589, p < 0.001; (1,59) = 4.037, p < 0.05; (1,59) = 4.307, p < 0.05. The oral administration of VAL and IMI significantly (p < 0.01) decreased mice immobility time in the TST 6 h after vehicle injection when compared to the vehicle-vehicle treated group and this effect was not observed when the animals were pretreated with VAL or IMI and received the LPS injection (Figure 3(b)) [(1,59) = 11.556, p < 0.001; (1,59) = 5.922, p < 0.01; (1,59) = 0.398, p = 0.674]. The locomotor activity of the animals returned to basal levels at 24 h (Figure 3(c)) [(1,59) = 0.0001; p = 0.992; (1,59) = 0.122, p = 0.885; (1,59) = 1.431, p = 0.248]. The forced swim + LPS administration significantly (p < 0.001) increased mice immobility time in the TST 24 h after the injection (Figure 3(d)) when compared to vehicle-vehicle treated animals, while VAL and IMI pretreatment prevented the forced swim + LPS-induced immobility injection [(1,59) = 6.601; p < 0.05; (1,59) = 4.721, p < 0.05; (1,59) = 10.863, p < 0.001].

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(d)

Figure 3

Effects of diene valepotriates from V. glechomifolia (VAL) pretreatment on sickness and depressive-like behavior induced by a stressful stimulus (6 min forced swimming session) + E. coli LPS injection in mice. The animals were orally treated with VAL (10 mg/kg, p.o.) or imipramine (IMI, used as a positive control, 20 mg/kg, p.o.) 1 hour before being exposed to the forced swim + LPS and were evaluated in the open field and tail suspension tests 6 h (Panels (a) and (b)) and 24 h after (Panels (c) and (d)) the immune challenge. Each column represents the mean ± S.E.M (n = 8–12 mice/group). Two-way ANOVA, post hoc Student-Newman-Keuls test. ; ; .

The effects of VAL or IMI posttreatment on forced swim + LPS-induced behavioral alterations are shown in Figure 4. Mice posttreatment with VAL, but not with IMI, prevented the forced swim + LPS-induced decrease in the locomotor activity assessed by the OFT 6 h after LPS injection (Figure 4(a)) [(1,58) = 9.755, p < 0.01; (1,58) = 8.3691, p < 0.001; (1,59) = 0.918, p = 0.406]. Mice orally posttreated with VAL and IMI presented a significant (p < 0.01) decrease in the immobility time in the TST 6 h after vehicle or LPS injection (Figure 4(b)) [(1,59) = 0.479, p = 0.492; (1,58) = 21.114, p < 0.001; (1,59) = 0.920, p = 0.406]. The locomotor activity of the animals returned to basal levels 24 h after LPS injection, as can be seen in Figure 4(c) [(1,59) = 0.135, p = 0.715; (1,59) = 0.896, p = 0.415; (1,59) = 2.036, p = 0.141]. Only VAL posttreatment was able to prevent (p < 0.01) the forced swim + LPS-induced increase in the immobility time in the TST 24 h after LPS injection [(1,59) = 3.405, p = 0.071; (1,59) = 1.749, p = 0.184; (1,59) = 9.876, p < 0.001].

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Figure 4

Effects of diene valepotriates from V. glechomifolia (VAL) posttreatment on sickness and depressive-like behavior induced by a stressful stimulus (6 min forced swimming session) + E. coli LPS injection in mice. The animals were orally treated with VAL (10 mg/kg, p.o.) or imipramine (IMI, used as a positive control, 20 mg/kg, p.o.) 5 hours after being exposed to the forced swim + LPS and were evaluated in the open field and tail suspension tests 6 h (Panels (a) and (b)) and 24 h after (Panels (c) and (d)) the immune challenge. Each column represents the mean ± S.E.M ( = 8–12 mice/group). Two-way ANOVA, post hoc Student-Newman-Keuls test. ; .

3.3. Effects of VAL and IMI on Forced Swim + LPS-Induced Alterations in the Expression of IL1-β, TNF-α, and BDNF Expression in the Cortex of Mice

The effects of pretreatment with VAL and IMI on forced swim + LPS-induced changes in the cortical expression of IL1-, TNF-, and BDNF are shown in Figure 5. The forced swim + LPS elicited a significant increase in the expression of IL1- (p < 0.001) (Figure 5(a)) and TNF- (p < 0.01) (Figure 5(b)) in the cortex of mice, while VAL and IMI pretreatment prevented this effect [IL1-: (6,28) = 23.76, p < 0.001; TNF-: F(6,28) = 32.21, p < 0.001]. Cortical BDNF expression was significantly (p < 0.001) reduced by the forced swim + LPS (Figure 5(c)). Nevertheless, mice pretreatment with VAL and IMI was not effective in preventing this effect [F(6,28) = 25.48, p < 0.001].

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Figure 5

Effects of diene valepotriates from V. glechomifolia (VAL) pretreatment on the alterations in the cortical expression of IL1- (Panel (a)), TNF- (Panel (b)), and BDNF (Panel (c)) induced by a stressful stimulus (6 min forced swimming session) + E. coli LPS injection in mice. The animals were orally treated with VAL (10 mg/kg, p.o.) or imipramine (IMI, used as a positive control, 20 mg/kg, p.o.) 1 hour before being exposed to the forced swim + LPS and the tissues were collected 25 h later. Each column represents the mean (n = 4 mice/group). One-way ANOVA, post hoc Student-Newman-Keuls test. ; versus Naïve group; versus Vehicle+LPS-treated group.

The effects of mice posttreatment with VAL and IMI on forced swim + LPS-induced alterations in the expression of IL1-, TNF-, and BDNF in mice cortex are depicted in Figure 6. The forced swim + LPS significantly increased (p < 0.001) the expression of IL1- (Figure 6(a)) and TNF- (Figure 6(b)), while a significant (p < 0.001) decrease in BDNF expression was found in the cortex of mice. The posttreatment with VAL or IMI did not prevent these alterations in the expression of proinflammatory cytokines [IL1-: F(5,28) = 23.89, p < 0.001; TNF-: (5, 28) = 83.54, p < 0.001] or BDNF [(5,58) = 31.84, p < 0.001].

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Figure 6

Effects of diene valepotriates from V. glechomifolia (VAL) posttreatment on the alterations in the cortical expression of IL1- (Panel (a)), TNF- (Panel (b)), and BDNF (Panel (c)) induced by a stressful stimulus (6 min forced swimming session) + E. coli LPS injection in mice. The animals were orally treated with VAL (10 mg/kg, p.o.) or imipramine (IMI, used as a positive control, 20 mg/kg, p.o.) 5 hours after being exposed to the forced swim + LPS and the tissues were collected 25 h later. Each column represents the mean (n = 4 mice/group). One-way ANOVA, post hoc Student-Newman-Keuls test. versus Naïve group; versus Vehicle + LPS-treated group.

4. Discussion

The present study demonstrated the positive effects of Valeriana glechomifolia diene valepotriates (VAL) in an animal model of depression that correlates the activation of inflammatory pathways with the manifestation of depression-like behavior. Also, the antidepressant-like effect of VAL was accompanied by normalization in the expression of cortical proinflammatory cytokines in E. coli LPS-injected animals previously submitted to a 6 min swimming session as a stressful stimulus. These findings are in accordance with Neamati and coworkers’ study [28], who reported that a hydroalcoholic extract of V. officinalis prevented the development of sickness and depression-like behavior in ovalbumin sensitized rats, which is an animal model of depression associated with inflammation. In line with these findings, accumulating evidence points to the antidepressant and anti-inflammatory potential of Valeriana species [25–27, 29, 30, 48].

Sickness behavior is a usual response to infection characterized by endocrine, autonomic, and behavioral changes triggered by the activation of the peripheral innate immune system [3]. In rodents, the sickness behavior can be detected by a reduction in locomotor activity and exploratory behaviors [49]. Herein, we demonstrated that the administration of LPS to mice previously submitted to a 6 min swimming session significantly decreased the locomotor activity 6 h after LPS, indicating the development of sickness behavior. There were no differences between the immobility time of the vehicle-treated and LPS-treated groups in the TST 6 h after the peripheral immune challenge, corroborating with the hypothesis that depression-like behavior develops over a background of sickness and peaks 24 h later [3]. No alterations in mice locomotor activity were observed 24 h after the immune challenge, confirming that the increased immobility time in the TST 24 h after LPS is due to the manifestation of depression-like behavior.

The pre- and posttreatment with VAL resulted in normalization of behavioral alterations elicited by LPS in mice previously submitted to a forced swimming session. On the other hand, mice posttreatment with IMI was not able to restore the forced swim + LPS-triggered effects. In fact, there are several studies in the literature demonstrating the preventive, but not the therapeutic, effects of antidepressants or natural products on LPS-induced behavioral alterations [13, 23, 24, 50]. However, other authors [18] demonstrated that mice posttreatment with IMI restored the depressive-like behavior elicited by the LPS injection. This could be due to the different experimental protocols used, since the animals used in our study were submitted to a forced swimming session before LPS injection (600 g/kg) and received an oral administration of IMI, whereas Ferreira Mello and coworkers [18] performed the LPS injection only (500 g/kg) and the administration of IMI by the i.p. route.

In our experiments, the antidepressant-like effects of VAL and IMI were accompanied by a decrease in the expression of IL-1 and TNF- in mice cortex, which is a cerebral area related to the pathophysiology of depression [51, 52]. Consistently, the pivotal proinflammatory cytokines involved in sickness and depression-related behaviors following infection are IL-1 and TNF- [3]. Thus, the effects of VAL and IMI on these cytokines may explain the positive results of VAL and IMI pretreatment in the behavioral tests. Of note, Jacobo-Herrera and coworkers [53] demonstrated that sesquiterpenes from V. officinalis showed inhibitory activity against the nuclear factor NF-kB in in vitro studies. These findings are particularly relevant, since this nuclear factor has been considered to play a role in the proinflammatory signaling pathway, mainly in the expression of proinflammatory genes including cytokines, such as IL-1 and TNF- [54] and is activated upon the interaction of Toll-like receptors with the LPS [55]. Considering that the valepotriates comprise a large family of terpenes [32], we may suggest that these compounds decrease the production of proinflammatory cytokines by inhibiting the NF-kB activation and modulating the activation of cytokine signaling, which results in the decrease of cortical cytokines expression and, consequently, normalization of behavioral alterations. In line with our findings, some ex vivo studies demonstrated that antidepressants decrease the levels of proinflammatory cytokines in the serum and brain of LPS-injected rodents [18, 20]. These data are supported by in vitro studies demonstrating the anti-inflammatory potential of antidepressants by using central and peripheral derived cells [56–58]. Also, the inhibition of microglia activation by terpenes has been demonstrated in an in vitro study [59] as well as the anti-inflammatory potential of these molecules in vivo [60–62]. To the best of our knowledge, there are no previous studies regarding the anti-inflammatory properties of diene valepotriates.

Interestingly, mice posttreatment with VAL, but not with IMI, prevented the forced swim + LPS-induced behavioral alterations and had no effects on IL-1 and TNF- expression in the cortex, while VAL pretreatment decreased the cortical expression of IL-1 and TNF-. These findings may suggest that the effects of VAL posttreatment on behavioral alterations could be due to its action on dopaminergic and noradrenergic neurotransmissions. Our research group showed that the acute antidepressant-like effect of VAL was prevented by mice pretreatment with yohimbine (2 adrenoceptor antagonist), SCH 23390 (D1 dopamine receptor antagonist), and sulpiride (D2 dopamine receptor antagonist) [37]. The findings of the present study may also suggest that VAL prevents the activation of IL-1 and TNF- signaling cascades, but it is not able to block these cascades once they were activated. Another possibility is that other brain regions, than cortex, might be involved in the anti-inflammatory effects of VAL posttreatment.

Our results demonstrate that the stressful stimulus followed by the peripheral immune challenge decreases the cortical expression of BDNF mRNA at 24 h after LPS and these findings are in agreement with several studies that used animal models of depression associated to inflammation [13, 18–20]. However, mice before and after treatment with VAL or IMI were not effective in preventing these alterations. In fact, several authors have reported that the acute administration of conventional antidepressants, including IMI, is not able to increase the expression of BDNF [63–67]. Moreover, our results suggest that VAL could exert its effects in the cortex acting mainly by inhibiting an inflammatory pathway and not by interfering with BDNF.

5. Conclusion

Altogether, the results so far reinforce the antidepressant-like potential of V. glechomifolia diene valepotriates and demonstrate the positive effects of these compounds in an animal model that associates the activation of inflammatory pathways to depression etiology. The behavioral effects of diene valepotriates administration to the animals were accompanied by the normalization of proinflammatory cytokines expression, which brings a new focus on the range of action of these molecules.

Abbreviations

ANOVA:	Analysis of variance
BDNF:	Brain derived neurotrophic factor
HPLC:	High performance liquid chromatography
IL:	Interleukin
IMI:	Imipramine
LPS:	Lipopolysaccharide
MDD:	Major depressive disorder
OFT:	Open field test
RT-qPCR:	Quantitative reverse transcription polymerase chain reaction
S.E.M:	Standard error of the mean
SCCO₂:	Supercritical CO₂
	Sistema de Autorização e Informação em Biodiversidade do Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis
TNF-α:	Tumor necrosis factor alpha
TST:	Tail suspension test
VAL:	Diene valepotriates fraction.

Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this paper.

Acknowledgments

The authors wish to acknowledge CNPq (Grant 480647/2011-9) and CAPES (PRODOC Edital 2010) Brazilian agencies as well as Programa de Pós Graduação em Ciências Farmacêuticas (PPGCF-UFRGS) for the financial support. The authors are thankful to Dr. Eduardo Cassel, Dr. Rubem Vargas, and Dr. Gilsane Lino von Poser, for assistance with the extraction and characterization of the fraction.

References

R. C. Kessler, P. Berglund, O. Demler et al., “The epidemiology of major depressive disorder: results from the National Comorbidity Survey Replication (NCS-R),” Journal of the American Medical Association, vol. 289, no. 23, pp. 3095–3105, 2003.
View at: Publisher Site | Google Scholar
J. Hannestad, N. Dellagioia, and M. Bloch, “The effect of antidepressant medication treatment on serum levels of inflammatory cytokines: a meta-analysis,” Neuropsychopharmacology, vol. 36, no. 12, pp. 2452–2459, 2011.
View at: Publisher Site | Google Scholar
R. Dantzer, J. C. O'Connor, G. G. Freund, R. W. Johnson, and K. W. Kelley, “From inflammation to sickness and depression: when the immune system subjugates the brain,” Nature Reviews Neuroscience, vol. 9, no. 1, pp. 46–56, 2008.
View at: Publisher Site | Google Scholar
M. Maes, I. Mihaylova, M. Kubera, M. Uytterhoeven, N. Vrydags, and E. Bosmans, “Increased plasma peroxides and serum oxidized low density lipoprotein antibodies in major depression: markers that further explain the higher incidence of neurodegeneration and coronary artery disease,” Journal of Affective Disorders, vol. 125, no. 1–3, pp. 287–294, 2010.
View at: Publisher Site | Google Scholar
M. Maes, “The cytokine hypothesis of depression: inflammation, oxidative & nitrosative stress (IO&NS) and leaky gut as new targets for adjunctive treatments in depression,” Neuroendocrinology Letters, vol. 29, no. 3, pp. 287–291, 2008.
View at: Google Scholar
Y. Dowlati, N. Herrmann, W. Swardfager et al., “A meta-analysis of cytokines in major depression,” Biological Psychiatry, vol. 67, no. 5, pp. 446–457, 2010.
View at: Publisher Site | Google Scholar
C. L. Raison and A. H. Miller, “Is depression an inflammatory disorder?” Current Psychiatry Reports, vol. 13, no. 6, pp. 467–475, 2011.
View at: Publisher Site | Google Scholar
R. C. Shelton, J. Claiborne, M. Sidoryk-Wegrzynowicz et al., “Altered expression of genes involved in inflammation and apoptosis in frontal cortex in major depression,” Molecular Psychiatry, vol. 16, no. 7, pp. 751–762, 2011.
View at: Publisher Site | Google Scholar
J. Mendlewicz, P. Kriwin, P. Oswald, D. Souery, S. Alboni, and N. Brunello, “Shortened onset of action of antidepressants in major depression using acetylsalicylic acid augmentation: a pilot open-label study,” International Clinical Psychopharmacology, vol. 21, no. 4, pp. 227–231, 2006.
View at: Publisher Site | Google Scholar
S. Akhondzadeh, S. Jafari, F. Raisi et al., “Clinical trial of adjunctive celecoxib treatment in patients with major depression: a double blind and placebo controlled trial,” Depression and Anxiety, vol. 26, no. 7, pp. 607–611, 2009.
View at: Publisher Site | Google Scholar
S.-H. Abbasi, F. Hosseini, A. Modabbernia, M. Ashrafi, and S. Akhondzadeh, “Effect of celecoxib add-on treatment on symptoms and serum IL-6 concentrations in patients with major depressive disorder: randomized double-blind placebo-controlled study,” Journal of Affective Disorders, vol. 141, no. 2-3, pp. 308–314, 2012.
View at: Publisher Site | Google Scholar
F. Frenois, M. Moreau, J. O'Connor et al., “Lipopolysaccharide induces delayed FosB/DeltaFosB immunostaining within the mouse extended amygdala, hippocampus and hypothalamus, that parallel the expression of depressive-like behavior,” Psychoneuroendocrinology, vol. 32, no. 5, pp. 516–531, 2007.
View at: Publisher Site | Google Scholar
A. F. Viana, I. S. Maciel, F. N. Dornelles et al., “Kinin B1 receptors mediate depression-like behavior response in stressed mice treated with systemic E. coli lipopolysaccharide,” Journal of Neuroinflammation, vol. 7, article no. 98, 2010.
View at: Publisher Site | Google Scholar
N. Müller, A.-M. Myint, and M. J. Schwarz, “Inflammatory biomarkers and depression,” Neurotoxicity Research, vol. 19, no. 2, pp. 308–318, 2011.
View at: Publisher Site | Google Scholar
K. T. Ota and R. S. Duman, “Environmental and pharmacological modulations of cellular plasticity: role in the pathophysiology and treatment of depression,” Neurobiology of Disease, vol. 57, pp. 28–37, 2013.
View at: Publisher Site | Google Scholar
T. Saarelainen, P. Hendolin, G. Lucas et al., “Activation of the TrkB neurotrophin receptor is induced by antidepressant drugs and is required for antidepressant-induced behavioral effects,” The Journal of Neuroscience, vol. 23, no. 1, pp. 349–357, 2003.
View at: Google Scholar
M. Adachi, M. Barrot, A. E. Autry, D. Theobald, and L. M. Monteggia, “Selective loss of brain-derived neurotrophic factor in the dentate gyrus attenuates antidepressant efficacy,” Biological Psychiatry, vol. 63, no. 7, pp. 642–649, 2008.
View at: Publisher Site | Google Scholar
B. S. Ferreira Mello, A. S. Monte, R. S. McIntyre et al., “Effects of doxycycline on depressive-like behavior in mice after lipopolysaccharide (LPS) administration,” Journal of Psychiatric Research, vol. 47, no. 10, pp. 1521–1529, 2013.
View at: Publisher Site | Google Scholar
J. Guo, P. Lin, X. Zhao et al., “Etazolate abrogates the lipopolysaccharide (LPS)-induced downregulation of the cAMP/pCREB/BDNF signaling, neuroinflammatory response and depressive-like behavior in mice,” Neuroscience, vol. 263, pp. 1–14, 2014.
View at: Publisher Site | Google Scholar
Y. Ohgi, T. Futamura, T. Kikuchi, and K. Hashimoto, “Effects of antidepressants on alternations in serum cytokines and depressive-like behavior in mice after lipopolysaccharide administration,” Pharmacology Biochemistry and Behavior, vol. 103, no. 4, pp. 853–859, 2013.
View at: Publisher Site | Google Scholar
R. M. Santiago, J. Barbiero, B. J. Martynhak et al., “Antidepressant-like effect of celecoxib piroxicam in rat models of depression,” Journal of Neural Transmission, vol. 121, no. 6, pp. 671–682, 2014.
View at: Publisher Site | Google Scholar
M. Nöldner and K. Schötz, “Inhibition of lipopolysaccharid-induced sickness behavior by a dry extract from the roots of Pelargonium sidoides (EPs 7630) in mice,” Phytomedicine, vol. 14, no. 1, pp. 27–31, 2007.
View at: Publisher Site | Google Scholar
C. C. Veloso, A. D. Bitencourt, L. D. M. Cabral et al., “Pyrostegia venusta attenuate the sickness behavior induced by lipopolysaccharide in mice,” Journal of Ethnopharmacology, vol. 132, no. 1, pp. 355–358, 2010.
View at: Publisher Site | Google Scholar
S.-M. Park, M.-S. Choi, N.-W. Sohn, and J.-W. Shin, “Ginsenoside Rg₃ attenuates microglia activation following systemic lipopolysaccharide treatment in mice,” Biological & Pharmaceutical Bulletin, vol. 35, no. 9, pp. 1546–1552, 2012.
View at: Google Scholar
M. Hattesohl, B. Feistel, H. Sievers, R. Lehnfeld, M. Hegger, and H. Winterhoff, “Extracts of Valeriana officinalis L. s.l. show anxiolytic and antidepressant effects but neither sedative nor myorelaxant properties,” Phytomedicine, vol. 15, no. 1-2, pp. 2–15, 2008.
View at: Publisher Site | Google Scholar
F. Khuda, Z. Iqbal, A. Khan, F. Nasir, and Y. Shah, “Anti-inflammatory activity of the topical preparation of Valeriana wallichii and Achyranthes aspera leaves,” Pakistan Journal of Pharmaceutical Sciences, vol. 26, no. 3, pp. 451–454, 2013.
View at: Google Scholar
Z.-L. Zhang, Y.-M. Zuo, Q.-H. Wang, H.-B. Xiao, and H.-X. Kuang, “Effects of Valeriana amurensis on the expressions of iNOS, COX-2 and IkappaCB-alpha in Alzheimer's disease model rat's brain,” Zhong Yao Cai, vol. 33, no. 4, pp. 581–583, 2010.
View at: Google Scholar
A. Neamati, F. Chaman, M. Hosseini, and M. H. Boskabady, “The effects of Valeriana officinalis L. hydro-alcoholic extract on depression like behavior in ovalbumin sensitized rats,” Journal of Pharmacy and Bioallied Sciences, vol. 6, no. 2, pp. 97–103, 2014.
View at: Publisher Site | Google Scholar
F. Subhan, N. Karim, A. H. Gilani, and R. D. E. Sewell, “Terpenoid content of Valeriana wallichii extracts and antidepressant-like response profiles,” Phytotherapy Research, vol. 24, no. 5, pp. 686–691, 2010.
View at: Publisher Site | Google Scholar
S. P. Sah, C. S. Mathela, and K. Chopra, “Antidepressant effect of Valeriana wallichii patchouli alcohol chemotype in mice: behavioural and biochemical evidence,” Journal of Ethnopharmacology, vol. 135, no. 1, pp. 197–200, 2011.
View at: Publisher Site | Google Scholar
L. D. A. Salles, A. L. Silva, S. B. Rech, N. Zanatta, and G. L. Von Poser, “Constituents of Valeriana glechomifolia Meyer,” Biochemical Systematics and Ecology, vol. 28, no. 9, pp. 907–910, 2000.
View at: Publisher Site | Google Scholar
F. Geu-Flores, N. H. Sherden, V. Courdavault et al., “An alternative route to cyclic terpenes by reductive cyclization in iridoid biosynthesis,” Nature, vol. 491, no. 7427, pp. 138–142, 2012.
View at: Publisher Site | Google Scholar
R. Andreatini and J. R. Leite, “Effect of valepotriates on the behavior of rats in the elevated plus-maze during diazepam withdrawal,” European Journal of Pharmacology, vol. 260, no. 2-3, pp. 233–235, 1994.
View at: Publisher Site | Google Scholar
A. Backlund and T. Moritz, “Phylogenetic implications of an expanded valepotriate distribution in the Valerianaceae,” Biochemical Systematics and Ecology, vol. 26, no. 3, pp. 309–335, 1998.
View at: Publisher Site | Google Scholar
R. Andreatini, V. A. Sartori, M. L. V. Seabra, and J. R. Leite, “Effect of valepotriates (valerian extract) in generalized anxiety disorder: a randomized placebo-controlled pilot study,” Phytotherapy Research, vol. 16, no. 7, pp. 650–654, 2002.
View at: Publisher Site | Google Scholar
N. Maurmann, G. K. Reolon, S. B. Rech, A. G. Fett-Neto, and R. Roesler, “A valepotriate fraction of valeriana glechomifolia shows sedative and anxiolytic properties and impairs recognition but not aversive memory in mice,” Evidence-Based Complementary and Alternative Medicine, vol. 2011, Article ID 720853, 7 pages, 2011.
View at: Publisher Site | Google Scholar
L. G. Müller, L. A. Salles, A. C. Stein et al., “Antidepressant-like effect of Valeriana glechomifolia Meyer (Valerianaceae) in mice,” Progress in Neuro-Psychopharmacology and Biological Psychiatry, vol. 36, no. 1, pp. 101–109, 2012.
View at: Publisher Site | Google Scholar
M. Maes, “Evidence for an immune response in major depression: a review and hypothesis,” Progress in Neuropsychopharmacology and Biological Psychiatry, vol. 19, no. 1, pp. 11–38, 1995.
View at: Publisher Site | Google Scholar
M. J. Robinson, S. E. Edwards, S. Iyengar, F. Bymaster, M. Clark, and W. Katon, “Depression and pain,” Frontiers in Bioscience, vol. 14, no. 13, pp. 5031–5051, 2009.
View at: Publisher Site | Google Scholar
E. Cassel, R. M. F. Vargas, G. W. Brun et al., “Supercritical fluid extraction of alkaloids from Ilex paraguariensis St. Hil,” Journal of Food Engineering, vol. 100, no. 4, pp. 656–661, 2010.
View at: Publisher Site | Google Scholar
L. G. Müller, L. de Andrade Salles, S. Sakamoto et al., “Effect of storage time and conditions on the diene valepotriates content of the extract of Valeriana glechomifolia obtained by supercritical carbon dioxide,” Phytochemical Analysis, vol. 23, no. 3, pp. 222–227, 2012.
View at: Publisher Site | Google Scholar
A. L. Silva, S. B. Rech, and G. L. Von Poser, “Quantitative determination of valepotriates from Valeriana native to South Brazil,” Planta Medica, vol. 68, no. 6, pp. 570–572, 2002.
View at: Publisher Site | Google Scholar
Ministério Público, Brasília, Brazil, Lei no. 11.794, de 8 de outubro de 2008, Publicada no DOU 9.10.2008.
Ministério da Ciência, Tecnologia e Inovação, and CONCEA, “Diretrizes da prática de eutanásia do CONCEA,” Portaria no. 596, de 25 de junho de 2013, Brasília, Brazil, 2013.
View at: Google Scholar
Ministério da Ciência, Tecnologia e Inovação, and CONCEA, “Diretriz brasileira para o cuidado e a utilização de animais para fins científicos e didáticos—DBCA,” Portaria no. 465, de 23 de maio de 2013, Brasília, Brazil, 2013.
View at: Google Scholar
L. Steru, R. Chermat, B. Thierry, and P. Simon, “The tail suspension test: a new method for screening antidepressants in mice,” Psychopharmacology, vol. 85, no. 3, pp. 367–370, 1985.
View at: Publisher Site | Google Scholar
S. Kwon, B. Lee, M. Kim, H. Lee, H.-J. Park, and D.-H. Hahm, “Antidepressant-like effect of the methanolic extract from Bupleurum falcatum in the tail suspension test,” Progress in Neuro-Psychopharmacology and Biological Psychiatry, vol. 34, no. 2, pp. 265–270, 2010.
View at: Publisher Site | Google Scholar
M. Neill and P. S. Dixon, “Effects of a preincisional 14-day course of valerian on natural killer cell activity in Sprague-Dawley male rats undergoing abdominal surgery,” Holistic Nursing Practice, vol. 21, no. 4, pp. 187–193, 2007.
View at: Publisher Site | Google Scholar
R. Dantzer, “Cytokine-induced sickness behavior: where do we stand?” Brain, Behavior, and Immunity, vol. 15, no. 1, pp. 7–24, 2001.
View at: Publisher Site | Google Scholar
J.-S. Lee, J.-H. Song, N.-W. Sohn, and J.-W. Shin, “Inhibitory effects of ginsenoside Rb1 on neuroinflammation following systemic lipopolysaccharide treatment in mice,” Phytotherapy Research, vol. 27, no. 9, pp. 1270–1276, 2013.
View at: Publisher Site | Google Scholar
E. J. Nestler and W. A. Carlezon Jr., “The mesolimbic dopamine reward circuit in depression,” Biological Psychiatry, vol. 59, no. 12, pp. 1151–1159, 2006.
View at: Publisher Site | Google Scholar
V. Krishnan and E. J. Nestler, “The molecular neurobiology of depression,” Nature, vol. 455, no. 7215, pp. 894–902, 2008.
View at: Publisher Site | Google Scholar
N. J. Jacobo-Herrera, N. Vartiainen, P. Bremner, S. Gibbons, J. Koistinaho, and M. Heinrich, “NF- $κ$ B modulators from Valeriana officinalis,” Phytotherapy Research, vol. 20, no. 10, pp. 917–919, 2006.
View at: Publisher Site | Google Scholar
T. Lawrence, “The nuclear factor NF-κB pathway in inflammation,” Cold Spring Harbor Perspectives in Biology, vol. 1, no. 6, Article ID a001651, 2009.
View at: Publisher Site | Google Scholar
J. A. C. de Souza, C. Rossa Jr., G. P. Garlet, A. V. B. Nogueira, and J. A. Cirelli, “Modulation of host cell signaling pathways as a therapeutic approach in periodontal disease,” Journal of Applied Oral Science, vol. 20, no. 2, pp. 128–138, 2012.
View at: Publisher Site | Google Scholar
M. Diamond, J. P. Kelly, and T. J. Connor, “Antidepressants suppress production of the Th1 cytokine interferon-γ, independent of monoamine transporter blockade,” European Neuropsychopharmacology, vol. 16, no. 7, pp. 481–490, 2006.
View at: Publisher Site | Google Scholar
H. Horikawa, T. A. Kato, Y. Mizoguchi et al., “Inhibitory effects of SSRIs on IFN-γ induced microglial activation through the regulation of intracellular calcium,” Progress in Neuro-Psychopharmacology and Biological Psychiatry, vol. 34, no. 7, pp. 1306–1316, 2010.
View at: Publisher Site | Google Scholar
D. Liu, Z. Wang, S. Liu, F. Wang, S. Zhao, and A. Hao, “Anti-inflammatory effects of fluoxetine in lipopolysaccharide(LPS)-stimulated microglial cells,” Neuropharmacology, vol. 61, no. 4, pp. 592–599, 2011.
View at: Publisher Site | Google Scholar
H. Chen, C. Xie, H. Wang et al., “Sesquiterpenes inhibiting the microglial activation from laurus nobilis,” Journal of Agricultural and Food Chemistry, vol. 62, no. 20, pp. 4784–4788, 2014.
View at: Publisher Site | Google Scholar
A. Jardón-Delgado, G. A. Magos-Guerrero, and M. Martínez-Vázquez, “Isolation of a new anti-inflammatory 20, 21, 22, 23, 24, 25, 26, 27-octanorcucurbitacin-typetriterpene from Ibervillea sonorae,” Natural Product Communications, vol. 9, no. 1, pp. 15–16, 2014.
View at: Google Scholar
U. R. Juergens, “Anti-inflammatory properties of the monoterpene 1.8-cineole: current evidence for co-medication in inflammatory airway diseases,” Drug Research, vol. 64, no. 12, pp. 638–646, 2014.
View at: Publisher Site | Google Scholar
S.-A. Tang, H. Zhu, N. Qin et al., “Anti-inflammatory terpenes from flowers of Inula japonica,” Planta Medica, vol. 80, no. 7, pp. 583–589, 2014.
View at: Publisher Site | Google Scholar
A. L. Coppell, Q. Pei, and T. S. C. Zetterström, “Bi-phasic change in BDNF gene expression following antidepressant drug treatment,” Neuropharmacology, vol. 44, no. 7, pp. 903–910, 2003.
View at: Publisher Site | Google Scholar
R. Molteni, F. Calabrese, F. Bedogni et al., “Chronic treatment with fluoxetine up-regulates cellular BDNF mRNA expression in rat dopaminergic regions,” International Journal of Neuropsychopharmacology, vol. 9, no. 3, pp. 307–317, 2006.
View at: Publisher Site | Google Scholar
R. S. Duman and L. M. Monteggia, “A neurotrophic model for stress-related mood disorders,” Biological Psychiatry, vol. 59, no. 12, pp. 1116–1127, 2006.
View at: Publisher Site | Google Scholar
E. Castrén, V. Võikar, and T. Rantamäki, “Role of neurotrophic factors in depression,” Current Opinion in Pharmacology, vol. 7, no. 1, pp. 18–21, 2007.
View at: Publisher Site | Google Scholar
K. Martinowich, H. Manji, and B. Lu, “New insights into BDNF function in depression and anxiety,” Nature Neuroscience, vol. 10, no. 9, pp. 1089–1093, 2007.
View at: Publisher Site | Google Scholar

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Copyright © 2015 Liz G. Müller et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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