Prophylactic effects of asiaticoside-based standardized extract of Centella asiatica (L.) Urban leaves on experimental migraine: Involvement of 5HT1A/1B receptors / 中国天然药物

The present study aimed at evaluation of prophylactic efficacy and possible mechanisms of asiaticoside (AS) based standardized extract of Centella asiatica (L.) Urban leaves (INDCA) in animal models of migraine. The effects of oral and intranasal (i.n.) pretreatment of INDCA (acute and 7-days subacute) were evaluated against nitroglycerine (NTG, 10 mg·kg(-1), i.p.) and bradykinin (BK, 10 μg, intra-arterial) induced hyperalgesia in rats. Tail flick latencies (from 0 to 240 min) post-NTG treatment and the number of vocalizations post-BK treatment were recorded as a measure of hyperalgesia. Separate groups of rats for negative (Normal) and positive (sumatriptan, 42 mg·kg(-1), s.c.) controls were included. The interaction of INDCA with selective 5-HT1A, 5-HT1B, and 5-HT1D receptor antagonists (NAN-190, Isamoltane hemifumarate, and BRL-15572 respectively) against NTG-induced hyperalgesia was also evaluated. Acute and sub-acute pre-treatment of INDCA [10 and 30 mg·kg(-1) (oral) and 100 μg/rat (i.n.) showed significant anti-nociception activity, and reversal of the NTG-induced hyperalgesia and brain 5-HT concentration decline. Oral pre-treatment with INDCA (30 mg·kg(-1), 7 d) showed significant reduction in the number of vocalization. The anti-nociceptive effects of INDCA were blocked by 5-HT1A and 5-HT1B but not 5-HT1D receptor antagonists. In conclusion, INDCA demonstrated promising anti-nociceptive effects in animal models of migraine, probably through 5-HT1A/1B medicated action.

Design, synthesis and antidepressive activity of duloxetine derivatives / 药学学报

In this paper, duloxetine was chosen as the lead compound. The pharmacophores with 5-HT(1A) antagonism activity were used to replace the naphthyl of duloxetine. A series of duloxetine derivatives had been designed and synthesized and whose structures were confirmed with elemental analysis, MS and H NMR. All synthesized compounds were tested by tail suspension test and forced swimming test in vivo. The test results revealed that most of the compounds have shown better activity than duloxetine at the same dosage. Some of them are worth to be studied further.

5-HT1A/1B receptors, alpha2-adrenoceptors and the post-receptor adenylate cyclase activation in the mice brain are involved in the antidepressant-like action of agmatine / 药学学报

This study is to explore the possible mechanisms of the antidepressant-like effect of agmatine. By using two traditional "behavior despair" model, tail suspension test and forced swimming test, we examined the effects of some monoamine receptor antagonists (including beta-adrenergic receptor antagonist propranolol, beta-adrenergic receptor antagonist/5-HT1A/1B receptor antagonist pindolol, alpha2-adrenergic receptor antagonists yohimbine and idazoxan and 5-HT3 receptor antagonist tropisetron) on the antidepressant-like action of agmatine in mice. Activity of adenylate cyclase (AC) in the synapse membrane from rat frontal cortex was determined by radioimmunoassay. Single dose of agmatine (5-40 mg x kg(-1), ig) dose-dependently decrease the immobility time in tail suspension test in mice, indicating an antidepressant-like effect. The effect of agmatine (40 mg x kg(-1), ig) was antagonized by co-administration of beta-adrenergic receptor antagonist/5-HT1A/1B receptor antagonist pindolol (20 mg x kg(-1), ip), alpha2-adrenergic receptor antagonists yohimbine (5-10 mg x kg(-1), ip) or idazoxan (4 mg x kg(-1), ip), but not beta-adrenergic receptor antagonist propranolol (5-20 mg x kg(-1), ip) and 5-HT3 receptor antagonist tropisetron (5-40 mg x kg(-1), ip). Agmatine (5-40 mg x kg(-1), ig) also dose-dependently decrease the immobility time in forced swimming test in mice. The effect of agmatine (40 mg x kg(-1), ig) was also antagonized by pindolol (20 mg x kg(-1), ip), yohimbine (5-10 mg x kg(-1), ip), or idazoxan (4 mg x kg(-1), ip). Incubation of agmatine (0.1-6.4 micromol x L(-1)) with the synaptic membrane extracted from rat frontal cortex activated the AC in a dose-dependent manner in vitro. While the effect of agmatine (6.4 micromol x L(-1)) was dose-dependently antagonized by pindolol (1 micromol x L(-1)) or yohimbine (0.25-1 micromol x L(-1)). Chronic treatment with agmatine (10 mg x kg(-1), ig, bid, 2 w) or fluoxetine (10 mg x kg(-1), ig, bid, 2 w) increased the basic activity, as well as the Gpp (NH)p (1-100 micromol x L(-1)) stimulated AC activity in rat prefrontal cortex. These results indicate that regulation on 5-HT1A/1B and alpha2 receptors, and activation AC in the frontal cortex is one of the important mechanisms involving in agmatine's antidepressant-like action.

The selective 5-HT(1A) receptor antagonist WAY-100635 increases neuronal activity of the basolateral nucleus of the amygdala in 6-hydroxydopamine-lesioned rats / 生理学报

In the present study, extracellular recording was used to examine the neuronal activity of the basolateral nucleus (BL) of the amygdala and the effects of systemic administration of the selective 5-HT(1A) receptor antagonist WAY-100635 on the neuronal activity in the normal rats and rats with 6-hydroxydopamine (6-OHDA)-produced lesions in the substantia nigra pars compacta (SNc). The results showed that the firing rates of BL projection neurons and interneurons were (0.39±0.04) Hz and (0.83±0.16) Hz in the normal rats, and (0.32±0.04) Hz and (0.53±0.12) Hz in 6-OHDA-lesioned rats. There was no significant difference in the firing rates of BL projection neurons and interneurons between the normal and 6-OHDA-lesioned rats. In the normal rats, all BL projection neurons fired in burst; 94% of BL interneurons fired in burst and 6% fired irregularly. In 6-OHDA-lesioned rats, 85% of BL projection neurons displayed a burst firing pattern and 15% fired irregularly; 86% of BL interneurons had a burst firing pattern and 14% fired irregularly. The distribution of firing patterns of projection neurons and interneurons in the BL in 6-OHDA-lesioned rats did not differ from that in the normal rats. Systemic administration of WAY-100635 at 0.1 mg/kg body weight did not change the mean firing rates of projection neurons and interneurons in the BL in both normal and 6-OHDA-lesioned rats. However, a higher dose of WAY-100635 at 0.5 mg/kg body weight significantly decreased the mean firing rate of BL projection neurons from (0.43±0.07) to (0.15±0.02) Hz in the normal rats (P<0.01), but significantly increased the activity of BL projection neurons in 6-OHDA-lesioned rats from (0.37±0.08) to (0.69±0.18) Hz (P<0.004). The mean firing rates of BL interneurons in the normal and 6-OHDA-lesioned rats did not change after administration of a higher dose of WAY-100635 at 0.5 mg/kg body weight. These results demonstrate that the activity of BL neurons after substantia nigra dopaminergic lesion in the SNc is regulated by activation of intrinsic and extrinsic inputs, and that 5-HT(1A) receptors significantly contribute to the regulation of the activity of BL projection neurons in both normal and 6-OHDA-lesioned rats. Furthermore, WAY-100635 induced an increase in the mean firing rate of projection neurons in the BL in 6-OHDA-lesioned rats, suggesting that 5-HT(1A) receptor is likely to play a role in generating affective symptoms in Parkinson's disease.

The selective 5-HT1A receptor antagonist WAY-100635 inhibits neuronal activity of the ventromedial prefrontal cortex in a rodent model of Parkinson's disease / 神经科学通报·英文版

<p><b>OBJECTIVE</b>The ventral part of the medial prefrontal cortex (mPFC) plays an important role in initiation and control of voluntary movement, mood and cognition. However, after the degeneration of the nigrostriatal pathway, the neuronal activity of the ventral mPFC and the role of serotonin(1A) (5-hydroxytryptamine, 5-HT(1A)) receptors in the firing of the neurons are still unknown. The present study is to investigate the change of neuronal activity in the ventral mPFC and the effect of systemic administration of the selective 5-HT(1A) receptor antagonist WAY-100635 on the activity of the neurons in normal and 6-hydroxydopamine (6-OHDA)-lesioned rats.</p><p><b>METHODS</b>Single unit responses were recorded extracellularly with glass microelectrodes from ventral mPFC neurons in normal rats and 6-OHDA unilaterally lesioned rats in vivo.</p><p><b>RESULTS</b>6-OHDA lesion of the substantia nigra pars compacta (SNc) significantly increased the firing rate with no change in the firing pattern of neurons of the ventral mPFC in rats. Systemic administration of WAY-100635 (0.1 mg/kg, i.v.) did not change the mean firing rate and firing pattern of ventral mPFC neurons in normal rats. In contrast, WAY-100635 significantly decreased the mean firing rate of the neurons in rats with 6-OHDA lesion of the SNc.</p><p><b>CONCLUSION</b>These data suggest that the degeneration of the nigrostriatal pathway results in an increase of neuronal activity of ventral mPFC and dysfunction of 5-HT(1A) receptor.</p>