Injection Of Reserpine Research Articles

Blockade of spinal α5-GABAA receptors differentially reduces reserpine-induced fibromyalgia-type pain in female rats

The role of spinal α5 subunit-containing GABAA (α5-GABAA) receptors in chronic pain is controversial. The purpose of this study was to investigate the participation of spinal α5-GABAA receptors in the reserpine-induced pain model. Reserpine administration induced tactile allodynia and muscle hyperalgesia in female and male rats. Intrathecal injection of L-655,708 and TB 21007 (7 days after the last reserpine injection) decreased tactile allodynia and, at a lesser extent, muscle hyperalgesia in female rats. The effects of these drugs produced a lower antiallodynic and antihyperalgesic effect in male than in female rats. Contrariwise, these drugs produced tactile allodynia and muscle hyperalgesia in naïve rats and these effects were lower in naïve male than female rats. Intrathecal L-838,417 prevented or reversed L-655,708-induced antiallodynia in reserpine-treated female rats. Repeated treatment with α5-GABAA receptor small interfering RNA (siRNA), but not scramble siRNA, reduced reserpine-induced allodynia in female rats. Accordingly, α5-GABAA receptor siRNA induced nociceptive hypersensitivity in naïve female rats. Reserpine enhanced α5-GABAA receptors expression in spinal cord and dorsal root ganglia (DRG), while it increased CD11b (OX-42) and glial fibrillary acidic protein (GFAP) fluorescence intensity in the lumbar spinal cord. In contrast, reserpine diminished K+-Cl- co-transporter 2 (KCC2) protein in the lumbar spinal cord. Data suggest that spinal α5-GABAA receptors play a sex-dependent proallodynic effect in reserpine-treated rats. In contrast, these receptors have a sex-dependent antiallodynic role in naïve rats.

Serotonergic dysfunction in a model of parkinsonism induced by reserpine

Parkinson’s disease (PD) is mainly characterized by a dopamine deficiency accompanied by structural and functional changes in striatal neuronal projections. However, studies have considered PD as a multi-systemic disease in which the neurodegenerative process extends beyond the dopaminergic system. Therefore, the purpose of the present study was to investigate the time-course of serotonergic neuron damage in a progressive model of parkinsonism induced by a low dose of reserpine. Thus, male Wistar rats received 4 (ST, short-treatment of reserpine) or 10 (MT, middle-term treatment of reserpine) subcutaneous injections of vehicle or reserpine (0.1 mg/kg) at a volume of 1 mL/kg body weight, on alternate days. Animals were euthanized 48 h after the last injection for immunohistochemical analysis. After ST, 5-HT immunoreactivity decreased in hippocampal subareas (CA1 and CA3) and medial prefrontal cortex (mPFC) compared to vehicle. Furthermore, animals MT-treated also showed progressive decrease of 5-HT immunoreactivity in CA1 and CA3 subareas. Conversely, a significant increase of 5-HT immunoreactivity was found in mPFC and dorsal raphe nucleus (DRN) in animals submitted to MT when compared to ST exposure. The results showed that, in the repeated low-dose reserpine rat model, variations in the immunoreactivity of 5-HT start early in the course of progressive parkinsonism.

Electrocortical and Biochemical Evaluation of Antidepressant Efficacy of Formulated Nanocurcumin.

The present study aims to evaluate the antidepressant efficacy of curcumin nanoparticles on rat model of depression induced by reserpine. Rats were divided into control, the rat model of depression induced by daily i.p. injection of reserpine (0.2mg/kg for 21days), and the rat model of depression treated daily with the formulated CNPs (20mg/kg for 7 and 15days). The behavioral evaluation was assessed for all groups of animals by the forced swim test (FST). Monoamine neurotransmitters were measured in the cortex and hippocampus via fluorescence spectroscopy. The electrophysiological evaluation was carried out by recording and analyzing the electrocorticogram (ECoG) in a group of animals that served as self-control. The chronic administration of reserpine resulted in a significant decrease in the duration of the active phase in the FST; a significant decrease in the cortical and hippocampal levels of serotonin, norepinephrine, and dopamine; a significant increase in spectral power of alpha and delta waves; and a significant decrease in spectral power of theta, beta-1, and beta-2 waves with respect to control values. Administration of CNPs for 7days has improved the performance of animals in FST indicated by the increase in the duration of the active phase. Additionally, the levels of serotonin and dopamine have been restored; however, the level of norepinephrine has been not completely recovered in both cortex and hippocampus. A significant increase in alpha and beta-2 waves, an increase in theta and beta-1, and a decrease in delta waves have been recorded after 7days of treatment. Extending treatment with CNPs for 15days has succeeded in restoring the active phase in FST and monoamine level in the cortex and hippocampus to control like values. In addition, ECoG waves have returned to near control like values. It could be concluded that the formulated nanocurcumin has an effective and potent antidepressant activity that was evidenced by electrical, chemical, and behavioral tests.

Monoamine system disruption induces functional somatic syndromes associated symptomatology in mice.

Functional somatic syndromes (FSS), a clinical condition manifesting a variety of unexplained somatic symptoms, has been proposed as an inclusive nosology encompassing individual syndromes such as fibromyalgia syndrome and irritable bowel syndrome. Accumulating evidence suggests that disturbance of the endogenous monoamine system could be involved in the aetiology of FSS. Therefore, the purpose of present study was to investigate whether the disturbance of the monoamine system would cause FSS-associated symptomatology in mice. The optimal dose of reserpine, an inducer of endogenous monoamines reduction, was first explored in mice. General body condition (body weight, rectal temperature, and ptosis) and FSS-associated symptomatology (paw withdrawal threshold, small intestinal transit, and locomotor activity) were measured. The concentration of monoamines was measured in central and peripheral tissues. Mice dosed with reserpine (0.25 mg/kg s.c., once daily for 3 consecutive days) exhibited a decrease in paw withdrawal threshold, delay in small intestinal transit, and reduction of locomotor activity without deterioration of general body condition on day 5 after the first reserpine injection. The concentration of monoamines was decreased in the central nervous system and skeletal muscle, but not in the small intestine. A reserpine dose of 0.5 mg/kg or more caused deterioration of general body condition. In conclusion, the optimal protocol of reserpine treatment for inducing pain symptom without deterioration of general physical condition is 0.25 mg/kg s.c., once daily for 3 consecutive days in mice. This protocol causes not only pain but also FSS-associated symptomatology which are associated with disruption of the endogenous monoamine system. The reserpine-treated animal may be useful for the research of not only fibromyalgia syndrome but also FSS, especially for the research focusing on the hypothesis that FSS is associated with the disturbance of endogenous monoamine system.

L-Theanine Decreases Orofacial Dyskinesia Induced by Reserpine in Rats.

Reserpine (RES)-induced orofacial dyskinesia (OD) has been used as an animal model for human tardive dyskinesia (TD) for decades, due to its strong pathophysiological association with striatal oxidative stress and neural cytoarchitecture alteration. L-Theanine (LT), one of the major amino acid components in green tea, has potent antioxidative, anti-inflammatory, and neuroprotective effects. In this study, we examined the potential protective effects of LT on RES-induced behavioral and neurochemical dysfunction in rats. RES treatment (1mg/kg s.c., 3 injections 1day apart) induced significant increases (p < 0.001) in the frequency of vacuous chewing movements (VCM), tongue protrusion (TP), as well as the duration of facial twitching (FT). LT treatment (100, 300mg/kg orally for 14days, starting 10days before RES injection) was able to prevent most of the RES-induced OD. Moreover, LT treatment reduced the RES-induced lipid peroxidation (LPO) production, increased the antioxidation power and catecholamines in the striatum, and significantly reduced the levels of neuroinflammatory and apoptotic markers. Our results indicated that LT was able to counteract the increased oxidative damage, neurotransmitter deficiency, neuroinflammation, and apoptosis induced by RES, and these results have demonstrated the possible neuroprotective effects of LT against RES-induced OD, including antioxidation, neurochemical deficiency prevention, antineuroinflammation, and antiapoptosis. These findings, therefore, suggest a potential role for LT to have a clinically relevant therapeutic effect in delaying or treating human TD.

Diadenosine Polyphosphates Suppress the Effects of Sympathetic Nerve Stimulation in Rabbit Heart Pacemaker.

The modulatory influence of diadenosine tetraphosphate (Ap4A) and diadenosine pentaphosphate (Ap5A) on the effect of intramural autonomic nerve stimulation in isolated rabbit sinoatrial node were examined. Electrical activity of the sinoatrial node was recorded intracellularly. Against the background of blockade of adrenergic effects with propranolol (3×10-6 M) or in preparations isolated 2 h after injection of reserpine (2 mg/kg), nerve stimulation induced short-term membrane hyperpolarization and diminished the sinus node firing rate. These phenomena were not affected by Ap4A or Ap5A (10-5 M). Under the action of atropine (3×10-6 M) that completely eliminated the cholinergic influences, nerve stimulation enhanced the sinus node firing rate by 17.30±3.45% from the initial rate. Both Ap4A and Ap5A moderated the stimulation-induced elevation of firing rate to 9.9±2.8 and 10.5±2.9%, respectively. The data suggest that diadenosine polyphosphates significantly modulate the sympathetic influences on the heart rhythm, but have no effect on the parasympathetic control over activity of sinoatrial node.

Effects of Fluorencarbonic Acid Derivative on the Levels of Monoamines and Their Metabolites in Brain Structures of Rats with Modeled Depression-Like State.

The effects of the new structural analogue of benactyzine, a derivative of fluorencarbonic acid, on monoamine levels in brain structures were studied in male Wistar rats with experimental depression. Depressive state in rats was modeled by single injection of reserpine (4 mg/kg). The concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT), and their metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), homovanilic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) in the hypothalamus and striatum were measured by HPLC. It was found that preliminary treatment (30 days) with the derivative of fluorencarbonic acid prevented a decrease in monoamine level in the hypothalamus (NE, 5-HT, and 5-HIAA) and striatum (DA, 5-HT, and 5-HIAA). The neurochemical shifts (correction of 5-HT deficiency and stabilization of DA and NE levels) correlated with the high antidepressant activity of this agent observed in Porsolt forced swimming test.

5-HT in the dorsal raphe nucleus is involved in the effects of 100-Hz electro-acupuncture on the pain-depression dyad in rats.

The pain-depression dyad is becoming widespread in the clinic and is attracting increasing attention. A previous study by our group found that 100-Hz electro-acupuncture (EA), but not 2-, 50- and 2/100-Hz EA, was effective against the reserpine-induced pain-depression dyad. This finding is in contrast to the fact that low-frequency EA is commonly used to treat supraspinal-originating diseases. The present study aimed to investigate the mechanism underlying the effects of 100-Hz EA on the pain-depression dyad. Repeated reserpine injection was found to induce allodynia and depressive behaviors in rats. It decreased 5-hydroxytryptamine (5-HT) levels and immunoreactive expressions in the dorsal raphe nucleus (DRN). 100-Hz EA alleviated the pain-depression dyad and upregulated 5-HT in the DRN of reserpine-injected rats. Intracerebroventricular injection of para-chlorophenylalanine, an inhibitor of 5-HT resynthesis, suppressed the upregulation of 5-HT in the DRN by 100-Hz EA and partially counteracted the analgesic and anti-depressive effects of 100-Hz EA. The present study was the first to demonstrate that 5-HT in the DRN is involved in mediating the analgesic and anti-depressive effects of 100-Hz EA on the pain-depression dyad. This finding provided a scientific basis for high-frequency EA as a potential treatment for the pain-depression dyad.

Pharmacological analysis of the increases in heart rate and diastolic blood pressure produced by (S)-isometheptene and (R)-isometheptene in pithed rats

BackgroundIsometheptene is a sympathomimetic drug effective in acute migraine treatment. It is composed of two enantiomers with diverse pharmacological properties. This study investigated in pithed rats the cardiovascular effects of (S)- isometheptene and (R)-isometheptene, and the pharmacological profile of the more potent enantiomer.MethodsThe effects of i.v. bolus injections (0.03, 0.1, 0.3, 1 and 3 mg/kg) of isometheptene racemate, (S)-isometheptene or (R)-isometheptene on heart rate and blood pressure were analyzed in control experiments. The enantiomer producing more pronounced tachycardic and/or vasopressor responses was further analyzed in rats receiving i.v. injections of prazosin (0.1 mg/kg), rauwolscine (0.3 mg/kg), propranolol (1 mg/kg) or intraperitoneal reserpine (5 mg/kg, -24 h).ResultsCompared to (R)-isometheptene, (S)-isometheptene produced greater vasopressor responses, whilst both compounds equipotently increased heart rate. The tachycardic responses to (S)-isometheptene were abolished after propranolol, but remained unaffected by the other antagonists. In contrast, the vasopressor responses to (S)-isometheptene were practically abolished after prazosin. Interestingly, after reserpine, the tachycardic responses to (S)-isometheptene were abolished, whereas its vasopressor responses were attenuated and subsequently abolished by prazosin.ConclusionsThe different cardiovascular effects of the isometheptene enantiomers are probably due to differences in their mechanism of action, namely: (i) a mixed sympathomimetic action for (S)-isometheptene (a tyramine-like action and a direct stimulation of α1-adrenoceptors); and (ii) exclusively a tyramine like action for (R)-isometheptene. Thus, (R)-isometheptene may represent a superior therapeutic benefit as an antimigraine agent.

Spontaneously Hypertensive Rats (SHR) Are Resistant to a Reserpine-Induced Progressive Model of Parkinson's Disease: Differences in Motor Behavior, Tyrosine Hydroxylase and α-Synuclein Expression.

Reserpine is an irreversible inhibitor of vesicular monoamine transporter-2 (VMAT2) used to study Parkinson’s disease (PD) and screening for antiparkinsonian treatments in rodents. Recently, the repeated treatment with a low-dose of reserpine was proposed as a progressive model of PD. Rats under this treatment show progressive catalepsy behavior, oral movements and spontaneous motor activity decrement. In parallel, compared to Wistar rats, spontaneously hypertensive rats (SHR) are resistant to acute reserpine-induced oral dyskinesia. We aimed to assess whether SHR would present differential susceptibility to repeated reserpine-induced deficits in the progressive model of PD. Male Wistar and SHR rats were administered 15 subcutaneously (s.c.) injections of reserpine (0.1 mg/kg) or vehicle, every other day and motor activity was assessed by the catalepsy, oral movements and open field tests. Only reserpine-treated Wistar rats presented increased latency to step down in the catalepsy test and impaired spontaneous activity in the open field. On the other hand, there was an increase in oral movements in both reserpine-treated strains, although with reduced magnitude and latency to instauration in SHR. After a 15-day withdrawn period, both strains recovered from motor impairment, but SHR animals expressed reduced latencies to reach control levels. Finally, we performed immunohistochemistry for tyrosine hydroxylase (TH) and α-synuclein (α-syn) 48 h after the last injection or 15 days after withdrawn. Reserpine-treated animals presented a reduction in TH and an increase in α-syn immunoreactivity in the substantia nigra and dorsal striatum (dSTR), which were both recovered after 15 days of withdraw. Furthermore, SHR rats were resistant to reserpine-induced TH decrement in the substantia nigra, and presented reduced immunoreactivity to α-syn in the dSTR relative to Wistar rats, irrespective of treatment. This effect was accompanied by increase of malondaldhyde (MDA) in the striatum of reserpine-treated Wistar rats, while SHR presented reduced MDA in both control and reserpine conditions relative to Wistar strain. In conclusion, the current results show that SHR are resilient to motor and neurochemical impairments induced by the repeated low-dose reserpine protocol. These findings indicate that the neurochemical, molecular and genetic differences in the SHR strain are potential relevant targets to the study of susceptibility to PD.

INDUCTION OF DEPRESSION MODEL IN MICE: IMPLICATION OF DIFFERENT RESERPINE DOSES

Depression is a mood disorder whose main clinic characteristics include lasting low motion, decrease in motivate ability and slowness in function of thinking and recognizing .It is showed in national survey that the suicide rate of people suffering from depression is 20 times higher than that of normal people. The present study aimed to select the most suitable dose of reserpine for induction of depression in mice with minimal side effects and minimal mortality rate. Depression was induced in mice by a single i.p. reserpine injection at different dose (0.1, 0.5 and 1 mg/kg) at the day 1, then forced swimming test was performed 1 hour later at the first day. The duration of the experiment was 2 days. The mortality rate was recorded, The brain was excised and prepared for determination of the content of the Adenosine monophosphate (AMP), adenosine Diphosphate (ADP) and Adenosine triphosphate (ATP), Monoamine neurotransmitters (5-HT, DA and NE), Malondialdehyde (MDA), Nitric oxide (NO), Glutathione reduced (GSH), oxidized (GSSG) and 8- hydroxyl-2-deoxyguanosine (8-OHDG). The forced swimming test and number of jumping showed no significant difference between different doses while the mortality rate was markedly variable. The results concluded that the most suitable reserpine dose for inducing depression with minimal mortality was 0.1 mg/kg of body weight.

ESTABLISHMENT AND EVALUATION OF ORTHOTOPIC HEPATOCELLULAR CARCINOMA AND DRUG-INDUCED HEPATOCELLULAR CARCINOMA IN MICE WITH SPLEEN-DEFICIENCY SYNDROME IN TRADITIONAL CHINESE MEDICINE.

Background:Spleen-deficiency syndrome (SDS) in Traditional Chinese Medicine (TCM) played pivotal roles on the development of hepatocellular carcinoma (HCC). This study was performed to establish and evaluate HCC model in mice with SDS in TCM.Material and Methods:A total of 90 C57BL/6 mice were randomized in six groups (n=15 for each group): A, Control group; B, SDS group; C, orthotopic HCC (OHCC) group; D, OHCC based on SDS (SDS-OHCC) group; E, Drug-induced HCC (DHCC) group; F, DHCC based on SDS (SDS-DHCC) group. The SDS model were established by subcutaneous injection of reserpine, followed by the OHCC or DHCC model establishment. The SDS scores, tumor formation rate and survival time were recorded and calculated, as well as the histochemical stain was performed.Results:The SDS scores of mice in Group B, D, F were 17.57±4.86 (P<0.05 vs. Group A), 18.13±4.53 (P<0.05 vs. Group A and C) and 23.32±4.94 (P<0.05 vs. Group A and E) respectively. The tumor formation rate of mice in Group C, D, E and F were 73.33%, 100%, 60% and 80% respectively. The survival time of mice in Group C, D, E and F were 26.42±5.27, 17.33±4.76 (P<0.05 vs. Group C), 35.77±6.12 and 22.61±5.05 (P<0.05 vs. Group E) respectively.Conclusion:The SDS-oriented HCC mice models were simple and easily-operated models for further studies on SDS oriented tumor. Meanwhile, SDS was a pivotal factor for low outcome of hepatic tumor.Abbreviations: HCC, Hepatocellular carcinoma; OHCC, Orthotopic hepatocellular carcinoma; DHCC, Drug-induced hepatocellular carcinoma; SDS, Spleen-deficiency syndrome; TCM, Traditional Chinese Medicine; SPF, Specific pathogen-free; DEN, Diethylnitrosamine; CCl4, Carbon tetrachloride; HE, Hematoxylin-eosin; IACUC, Institutional Animal Care and Use Committee.

Pain-depression dyad induced by reserpine is relieved by p,p'-methoxyl-diphenyl diselenide in rats

Depression and pain comorbidity represent a neuropsychiatric condition with substantial socioeconomic impact to society. The commonly used antidepressants and analgesics to treat this comorbidity have shown restricted clinical efficacy. In this way, the aim of this study was to investigate the behavioral, biochemical and neurochemical effects of a p,p'-methoxyl-diphenyl diselenide (OMePhSe)2 supplemented diet on pain-depression dyad induced by reserpine in rats. Adult Wistar rats were fed with 10mg (MeOPhSe)2 per kg of rat chow supplemented diet for 30 days. Pain-depression dyad was induced by daily subcutaneous reserpine injection (0.5mg/kg for three consecutive days) from 22 to 24 day of (MeOPhSe)2 supplementation. The results showed that the reserpine injected rats had behavior phenotypes typical of depression-pain dyad and the (MeOPhSe)2-supplemented diet protected against these modifications. Furthermore, the (MeOPhSe)2 dietary supplementation was effective against the increase in the prefrontal cortical MDA levels caused by reserpine. (MeOPhSe)2-supplemented diet triggered a per se augmentation of Nrf-2 levels. The [3H] serotonin uptake, [3H] glutamate uptake and release and MAO activity were not altered in the prefrontal cortices of rats from any experimental group. Therefore, the results indicate that protective effects of a (MeOPhSe)2-supplemented diet can be mediated, at least in part, by its antioxidant property.

P.7.d.003 - Polyunsaturated omega-3 fatty acids are not effective for depressive and compulsive symptoms in adolescent girls with anorexia nervosa

Depression and pain comorbidity represent a neuropsychiatric condition with substantial socioeconomic impact to society. The commonly used antidepressants and analgesics to treat this comorbidity have shown restricted clinical efficacy. In this way, the aim of this study was to investigate the behavioral, biochemical and neurochemical effects of a p,p'-methoxyl-diphenyl diselenide (OMePhSe)2 supplemented diet on pain-depression dyad induced by reserpine in rats. Adult Wistar rats were fed with 10 mg (MeOPhSe)2 per kg of rat chow supplemented diet for 30 days. Pain-depression dyad was induced by daily subcutaneous reserpine injection (0.5 mg/kg for three consecutive days) from 22 to 24 day of (MeOPhSe)2 supplementation. The results showed that the reserpine injected rats had behavior phenotypes typical of depression-pain dyad and the (MeOPhSe)2-supplemented diet protected against these modifications. Furthermore, the (MeOPhSe)2 dietary supplementation was effective against the increase in the prefrontal cortical MDA levels caused by reserpine. (MeOPhSe)2-supplemented diet triggered a per se augmentation of Nrf-2 levels. The [3H] serotonin uptake, [3H] glutamate uptake and release and MAO activity were not altered in the prefrontal cortices of rats from any experimental group. Therefore, the results indicate that protective effects of a (MeOPhSe)2-supplemented diet can be mediated, at least in part, by its antioxidant property.

Coadministration of Resveratrol and Rice Oil Mitigates Nociception and Oxidative State in a Mouse Fibromyalgia-Like Model.

The mechanism underlying pain symptoms in fibromyalgia (FM) is not fully understood. Oxidative stress has emerged as pathophysiological event occurring during the development of the disease. The present study aimed at investigating the efficacy of resveratrol associated with rice bran oil on fibromyalgia-like mice model. Subcutaneous injection of reserpine (0.25 mg/Kg) during 3 days produced fibromyalgia-like symptoms. Resveratrol and/or rice oil or pregabalin were administered through oral route in therapeutic (single dose) and preventive (four doses) schemes. In both schemes, treatment with resveratrol associated with rice bran oil and pregabalin significantly reduced mechanical allodynia and thermal hyperalgesia in animals. The preventive scheme displayed antidepressant effect which was demonstrated by the forced swimming test as well as reduced reactive species in the cerebrospinal fluid of reserpinized animals. Taken together, our data provide evidences that the intake of resveratrol associated with rice bran oil plays antinociceptive and antidepressant actions probably through reducing reactive species and suggests the involvement of oxidative stress in this model of FM as possible underlying mechanism of pathogenesis of the disease.

Nitric oxide pathway activity modulation alters the protective effects of (−)Epigallocatechin-3-gallate on reserpine-induced impairment in rats

Reserpine (RES) has been reported to increase the brain’s neural oxidative stress and cause cognitive dysfunction. Having powerful antioxidative properties, green tea catechins, especially (−)epigallocatechin-3-gallate (EGCG), are able to protect against many oxidative injuries. In this study, we examined the protecting properties of EGCG on RES-induced impairment of short-term memory in three-month-old male Wistar rats. RES (1mg/kg i.p.) induced memory impairment (p<0.001) as evaluated by the social recognition task. EGCG treatment (100mg/kg i.p. for 7days, starting 6days before RES injection) was able to improve the impaired memory caused by RES. RES treatment increased the nitric oxide (NO) level and lipid peroxidation (LPO) production, and decreased the antioxidation power in hippocampi. EGCG treatment was able to counteract the RES-induced NO level and LPO production, as well as enhanced the hippocampal antioxidation power in RES-treated rats. In order to examine the implication of NO pathway activity in RES treatment, either NO precursor (L-arginine; L-A) or NO synthase inhibitor (L-NAME; L-N) was co-pretreated with EGCG; NO precursor treatment eliminated the protective effect of EGCG, in contrast to that NO synthase inhibitor treatment significantly increased the EGCG effects on cognitive and biochemical protection in RES-treated rats. These results suggested that the NO pathway was implicated, at least in part, in the RES-induced impairment, as well as in the protective effect of EGCG in treating RES-induced impairment of memory. The above evidence provides a clinically relevant value for EGCG in preventing RES-induced cognitive dysfunction.

Response of Hematopoietic Stem and Progenitor Cells to Reserpine in C57Bl/6 Mice.

We studied the response of hematopoietic stem cells and progenitor cells to sympatholytic reserpine in intact C57Bl/6 mice and in animals with cyclophosphamide-induced leukopenia. The count of long-term hematopoietic stem cells (Lin(-)Sca-1(+)c-kit(+)CD34(-)) in the bone marrow of healthy mice increased in 7 min after reserpine injection and remained elevated in 2 h in parallel with elevated content of short-term stem (Lin(-)Sca-1(+)c-kit(+)CD34(+)) and progenitor (Lin(-)Sca-1(+)c-kit(+)) cells. Reserpine produced no effect on recruitment of hematopoietic stem and progenitor cells into the peripheral blood, but increased the serum level of granulocyte CSF and increased the count of metamyelocytes and neutrophilic granulocytes in the blood (in 2 h postinjection). Transplantation of bone marrow hematopoietic stem and progenitor cells from reserpine-treated donor C57Bl/6 mice to recipient CBA mice with 5-fluorouracil-induced leukopenia accelerated regeneration of the granulocytic lineage cells in leukemic mice. In cyclophosphamide-treated C57Bl/6 mice, reserpine reduced the level of short-term hematopoietic stem cells and increased the count of progenitor hematopoietic cells in the bone marrow in parallel with recruitment of the progenitors into the peripheral blood.

Combination of resveratrol and fluoxetine in an acute model of depression in mice: Prevention of oxidative DNA fragmentation and monoamines degradation

Resveratrol (RSV) is a natural polyphenol with diverse biological activities, including potent hepato-protective and antidepressant-like effects. Fluoxetine (FLX) is one of the most commonly prescribed antidepressant drugs, however; it has recently been postulated to induce liver damage. The present study aimed to assess the benefits of combining half the conventional doses of RSV and FLX in an acute reserpine model of depression. Depression was induced in mice by a single i.p. reserpine injection. Oral administration of FLX (10 mg/kg), RSV (80 mg/kg) or their combination (FLX; 5 mg/kg and RSV; 40mg/kg) started one hour after reserpine injection and daily for the following two consecutive days. Behavioral tests were performed on the third day. Brain monoamines were assessed. Prevention of neurodegeneration and preservation potential of the DNA integrity were determined according to the brain nitric oxide and 8 -hydroxy-2 –deoxyguanosine contents. Effect on oxidative stress in both brain and liver was evaluated. Results revealed that combining half the dose of FLX with RSV showed antidepressant activity that was comparable to the effect of using FLX alone and in conclusion; we recommend that further investigations should be conducted to assess the applicability of using combinations of RSV and FLX to treat depression.

(-)Epigallocatechin-3-gallate prevents the reserpine-induced impairment of short-term social memory in rats.

Reserpine has been confirmed to induce cognitive dysfunction and increase brain neural oxidative stress. Green tea catechins, particularly (-)epigallocatechin-3-gallate (EGCG), have strong antioxidative properties and can protect against numerous oxidative damages. In this study, we examined the possible protective effects of EGCG on reserpine-induced impairment of short-term memory in rats. Reserpine (1 mg/kg, intraperitoneal)-induced memory impairment was assessed using the social recognition task method; locomotor activity and the olfactory discrimination ability were not altered as measured by an open-field test and an olfactory discrimination test, respectively. EGCG treatment (100 and 300 mg/kg, intraperitoneal, for 7 days, starting 6 days before the reserpine injection) could improve the worsened social memory of reserpine-treated rats. Also, EGCG treatment reduced reserpine-induced lipid peroxidation and enhanced the antioxidation power in the hippocampi of reserpine-treated rats. These results suggest a protective effect of EGCG in treating reserpine-induced impairment of memory, most probably through its powerful antioxidative activities. Accordingly, EGCG may hold a clinically relevant value in preventing reserpine-induced cognitive dysfunction.

The metabolism of histamine in rat hypothalamus and cortex after reserpine treatment

The effect of reserpine on histamine (HA) and tele-methylhistamine (Nτ-MHA) in hypothalamus and cortex of rats was analyzed and compared to catecholamines. IP injection of reserpine (5 mg/kg) confirmed the effectiveness of reserpine treatment on noradrenaline and dopamine levels. Our in-vitro experiment with synaptosomal/crude mitochondrial fraction from hypothalamus and cortex confirmed that while mono amine oxidase (MAO) is an efficient metabolic enzyme for catecholamines, HA is not significantly affected by its enzymatic action. HMT activity after reserpine, pargyline and L-histidine treatment showed no differences compared to the control values. However HDC was significantly increased in both hypothalamus and cortex. In this study, Ws/Ws rats with deficiency of mast cells were used to clarify aspects of HA metabolism in HAergic neurons by eliminating the contribution of mast cells.The irreversible MAO-B inhibitor Pargyline (65 mg/kg) failed to accumulate Nτ-MHA in the hypothalamus. However, when animals treated with reserpine and pargyline/reserpine were compared, the last group showed higher Nτ-MHA values (p < 0.01). Moreover, the precursor of HA, L-histidine (1 g/kg), produced an increase of HA in the hypothalamus to 166% and the cortex to 348%.In conclusion, our results suggest that the effect of reserpine on the HA pools in the brain might be different. The neuronal HA pools are more resistant to reserpine as compared to those of catecholamine. Moreover, the HAergic pool appears to be more resistant to depletion than mast cells' pool, and thus HDC/HMT activity and its localization may play a key role in the understanding of HA metabolism in brain after reserpine treatment.