Ameliorating effect of emodin, a constitute of Polygonatum multiflorum, on cycloheximide-induced impairment of memory consolidation in rats

The aim of the present study was intended to investigate the ameliorating effects of emodin on memory consolidation via cholinergic, serotonergic and GABAergic neuronal systems in rats. First, we evaluated the ameliorating effects of emodin on cycloheximide (CXM)-induced impairment of passive avoidance response in rats. Secondly, we clarified the role of cholinergic, serotonergic or GABAergic system on the ameliorating effect of emodin by using 5-HT1A receptor partial agonist, 5-HT2 receptor antagonist, GABAB agonist, GABAA antagonist and muscarinic receptor antagonist. Emodin protected the rat from CXM-induced memory consolidation impairment. The beneficial effect of emodin on CXM-induced memory consolidation impairment was amplified by 8-OH-DPAT (5-HT1A receptor partial agonist) and ritanserin (5-HT2 receptor antagonist), but reduced by scopolamine. These results suggested that the beneficial effect of emodin on CXM-induced memory consolidation impairment was amplified by serotonergic 5-HT1A-receptor partial agonist and 5-HT2 receptor antagonist but reduced by muscarinic receptor antagonist.     

Effect of Indian Hypericum perforatum Linn on animal models of cognitive dysfunction

The effect of a standardised 50% ethanolic extract of Indian Hypericum perforatum (IHp) was investigated for its putative nootropic activity on various experimental paradigms of learning and memory, viz. transfer latency (TL) on elevated plus-maze, passive avoidance (PA), active avoidance (AA), scopolamine and sodium nitrite induced amnesia (SIA & NIA) in albino rats. Pilot studies indicated that single dose administration of IHp had little or no acute behavioural effects, hence the extract of IHp was administered orally at two dose levels (100 and 200 mg/kg, p.o.), once in daily for three consecutive days, while piracetam (500/kg, i.p.), a clinically used nootropic agent, was administered acutely to rats as the standard drug. Control rats were treated with equal volume of vehicle (0.3% carboxymethyl cellulose (CMC)). IHp and piracetam when given alone shortened the TL on day 1, 2, 9 and also antagonised the amnesic effects of scopolamine and sodium nitrite on the TL significantly. IHp had no significant per se effect on the retention of the PA in rats. Only the higher dose (200 mg/kg, p.o.) produced a significant reversal of scopolamine induced PA retention deficit but no significant reversal was observed with sodium nitrite. Piracetam showed significant per se facilitatory effect on PA retention and also reversed the scopolamine and sodium nitrite induced impaired PA retention. In the AA test, IHp in both the doses, and piracetam, facilitated the acquisition and retention of AA in rats and the IHp effects were found to be dose dependent. Both the doses of IHp and piracetam significantly attenuated the scopolamine and sodium nitrite induced impaired retention of AA. These results indicate a possible nootropic action of IHp, which was qualitatively comparable with that induced by piracetam.     

Psychopharmacological profile of the alkaloid psychollatine as a 5HT2A/C serotonin modulator

Behavioral effects of psychollatine, a new glycoside indole monoterpene alkaloid isolated from Psychotria umbellata, was investigated in models of anxiety, depression, memory, tremor, and sedation related to 5-HT and/or GABA neurotransmission. The GABA antagonist picrotoxin and the 5-HT2 antagonist ritanserin were used to examine the role of GABA and 5-HT2 receptors in psychollatine-induced effects. In the light/dark and hole-board models of anxiety, diazepam (0.75 mg/kg) and psychollatine (7.5 and 15 mg/kg) showed anxiolytic-like effect at doses that do not increase sleeping time nor alter spontaneous locomotor activity. The anxiolytic effect of psychollatine was prevented by prior administration of ritanserin, but not of picrotoxin, indicating that 5-HT2 but not GABA receptors are implicated. In the forced swimming model of depression, psychollatine (3 and 7.5 mg/kg) effects were comparable to the antidepressants imipramine (15 mg/kg) and fluoxetine (20 mg/kg). Psychollatine suppressed oxotremorine-induced tremors in all doses. In the step-down learning paradigm, diazepam (0.85 mg/kg), MK-801 (0.15 mg/kg), and psychollatine 100 mg/kg impaired the acquisition of learning and memory consolidation, without interfering with retrieval. It is concluded that the effects of psychollatine at the central nervous system involve serotonergic 5HT2(A/C) receptors.     

Brain neurotransmitter receptor binding and nootropic studies on Indian Hypericum perforatum Linn

The high affinity binding sites for serotonin and benzodiazepine in the frontal cortex, for dopamine in the striatum and muscarinic cholinergic receptors in the hippocampus were investigated in the brains of Charles Foster rats treated for 3 days. Transfer latency on elevated plus maze (TL), passive and active avoidance behaviour (PA and AA) and electroconvulsive shock (ECS) induced amnesia were also studied. Pilot studies indicated that single dose administration of Indian Hypericum perforatum (IHp) had little or no acute behavioural effects and hence the extract of IHp was administered orally at two dose levels (100 and 200 mg/kg, p.o.) once daily for 3 consecutive days, while piracetam (500 mg/kg, i.p.), a clinically used nootropic agent, was administered acutely to rats as the standard nootropic agent. Control rats were treated with an equal volume of vehicle (0.3% carboxymethyl cellulose). The results indicate that IHp treatment caused a significant decrease in the binding of [3H] spiroperone (DA-D2 receptor) to the striatum and an increase in the binding of [3H] ketanserin (5-HT2A receptor) and [3H] flunitrazepam (BDZ receptor) to the frontal cortex in rats. Preliminary pharmacological studies with IHp extract indicate the presence of two major behavioural actions, namely, antidepressant and anxiolytic. The present findings tend to elucidate the mechanism of earlier observations, the downregulation of the dopamine D2 receptor being consonant with anxiolytic and the upregulation of 5-HT2A and BDZ receptors being consonant with antidepressant activity. Piracetam when given alone, shortened the TL on days 1, 2 and 9 day and also antagonized the amnesic effects of ECS on the TL significantly, whereas IHp antagonized the amnesia produced by ECS. IHp had no significant effect per se on the retention of the PA in rats but produced a significant reversal of ECS induced PA retention deficit. Piracetam showed a significant facilitatory effect per se on PA retention and also reversed the ECS induced impaired PA retention. In the AA test, piracetam facilitated the acquisition and retention of AA in rats but IHp had no effect per se. Both the doses of IHp and piracetam significantly attenuated the ECS induced impaired retention of AA. These results indicate a possible nootropic action of IHp in amnesic animals, which was comparable qualitatively to piracetam.     

Effects of Hypericum perforatum extract on diabetes‐induced learning and memory impairment in rats

Cognitive impairment occurs in diabetes mellitus. Hypericum perforatum has been used in folk medicine to improve mental performance. Here it is hypothesized that chronic treatment with an extract of Hypericum perforatum (6, 12 and 25 mg/kg, p.o.) would have effects on passive avoidance learning (PAL) and memory in control and streptozotocin‐induced diabetic rats. Treatments were begun at the onset of hyperglycaemia. PAL was assessed 30 days later. A retention test was done 24 h after training. At the end, the animals were weighed and blood samples were drawn for plasma glucose measurement. Diabetes caused impairment in acquisition and retrieval processes of PAL and memory. Hypericum treatment (12 and 25 mg/kg) improved learning and memory in control rats and reversed learning and memory deficits in diabetic rats. A dose of 6 mg/kg did not affect cognitive function. Hypericum administration did not alter the body weight and plasma glucose levels. Antioxidant properties and cholinergic facilitatory effects of Hypericum may be involved in its nootropic effects. These results show that Hypericum perforatum prevented the deleterious effects of diabetes on PAL and memory. As Hypericum would be free of major side effects compared with other nootropic medications, it may provide a new potential alternative for demented diabetic patients. Copyright © 2010 John Wiley & Sons, Ltd.     

Effect of Hypericum perforatum on marble-burying by mice

The effect of Hypericum perforatum extract (LI 160) at a dose that exerts an antidepressive-like effect was studied in mice in the marble-burying test. Acute Hypericum perforatum (150, 300 and 500 mg/kg, p.o.) reduced immobility time in the forced swimming test. The number of marbles buried, but not locomotor activity, was reduced by acute treatment with Hypericum perforatum (150 and 300 mg/kg, p.o.). However, this effect was not seen after chronic treatment (21 days) with Hypericum perforatum (300 mg/kg, p.o.). Thus, Hypericum perforatum extract, at antidepressant dose, exerts an acute anxiolytic drug effect on the marble-burying test, which could indicate a potential anti-obsessive effect, although the development of tolerance could be an important drawback.     

Pharmacological study on antidepressant activity of 50% ethanol extract of a formulated ayurvedic product in rats

The effects of 50% ethanol extract of one formulated ayurvedic product, consisting of a mixture of medicinal plant species, was investigated on behavioral despair test (forced swimming test, FST), central dopaminergic and serotonergic activity in rats. The effects on the forced swimming test were assessed along with the levels of dopamine (DA), serotonin (5-HT) and its metabolites homovanillic acid (HVA) and 5-hydroxyindoleaceticacid (5-HIAA) in striatum, frontal cortex, hippocampus, hypothalamus and brain stem after 21 days of chronic oral administration of the extract (500 and 1500 mg/kg-body weight). The extract significantly increased climbing behavior at 500 mg/kg and increased swimming behavior by reducing immobility time at 1500 mg/kg when compared with the control group in forced swimming test (P<0.05). This showed that the active substances present in 50% ethanol extract of the ayurvedic preparation possess antidepressant activity and their specificity towards particular behavior, depends on the concentration of the extract. Further it showed that the enhancement of active behavior in FST is not due to generalized motor activity. The neurochemical estimations revealed the swim stressor inducing alterations in the levels of DA, 5-HT and their metabolites HVA and 5-HIAA in the brain regions assayed as compared with the non-stressed control rats. These changes were prevented extract treated rats. The 500 mg/kg extract treated group had significantly increased the levels of DA in frontal cortex, hypothalamus and hippocampus whereas the 5-HT in hypothalamus (P<0.05). However, there were no significant changes in the levels of HVA and 5-HIAA. These behavioral and biochemical results indicate antidepressant properties of the extract, which may be mediated by the dopaminergic and serotonergic mechanisms in rat brain.     

罗布麻叶总黄酮抗抑郁作用参与5-HT能系统可能机制的研究

该研究采用经典抗抑郁模型强迫游泳实验对罗布麻叶总黄酮的抗抑郁活性进行了评价,同时选择相关5-HT受体阻断剂(5-HT1A→Way100635、5-HT2→赛庚啶、5-HT2A→酮舍林)采用小鼠悬尾实验来探讨罗布麻叶总黄酮的抗抑郁机制。结果表明罗布麻叶总黄酮具有明确的抗抑郁作用;同时,5-HT2A、5-HT2受体阻断剂酮舍林(5mg/kg)、赛庚啶(3mg/kg)与罗布麻叶总黄酮50mg/kg联合连续灌胃给药10天后与罗布麻叶总黄酮50mg/kg单独给药相比,能明显延长悬尾小鼠累计不动时间(P<0.05),表明罗布麻叶总黄酮的抗抑郁活性与5-羟色胺能系统(5-HT2A、5-HT2受体)有关。     

高度富集黄酮类成分的贯叶连翘提取物抗抑郁作用

目的探讨贯叶连翘提取物中高度富集的黄酮类成分的抗抑郁作用。方法采用小鼠强迫游泳实验、小鼠悬尾实验、开野实验和拮抗利血平所致的体温降低实验,分别以小鼠不动时间、自主活动数和体温下降值作为评价指标。结果在强迫游泳和悬尾实验中,40,80,160,240mg/kg剂量组贯叶连翘提取物均能显著缩短小鼠不动时间,20mg/kg剂量组无显著性差异;开野实验结果表明给药后小鼠的自主活动不同程度地减少;在利血平拮抗实验中,30,60,120mg/kg剂量组在3h,4h和5h各时间点体温下降值与模型对照组相比有显著性差异,240和480mg/kg两剂量组在各测定时间点体温下降值与模型对照组相比均有显著性差异。结论高度富集总黄酮的贯叶连翘提取物(弃除贯叶金丝桃素)有抗抑郁作用。     

贯叶连翘提取物抗抑郁作用研究

目的：研究贯叶连翘提取物对小鼠的抑制郁作用。方法：选取了强迫小鼠游泳实验，小鼠尾悬吊应激实验，拮抗利血平所致的抑制症状等实验指标。结果：贯叶连翘提取物150mg/kg,300mg/kg显著缩短迫游泳小鼠及尾悬吊小鼠的不动时间；显著拮抗利血平所致的体温下降作用和小鼠眼睑下垂作用。结论：贯叶连翘提取物具有一定的抗抑郁作用。     

Effects of an aqueous extract of Puerariae flos (Thomsonide) on impairment of passive avoidance behavior in mice

The effects of an aqueous extract of Puerariae flos (Thomsonide) on ethanol-induced learning and memory impairment and scopolamine-induced amnesia were investigated. Thomsonide exerted an ameliorating effect on the impairment of both memory registration and memory retrieval induced by ethanol. These results indicate that Thomsonide has an antiamnesic effect on the central nervous system in alcoholic intoxication and support the traditional use of Puerariae flos for the treatment of alcoholic intoxication. Thomsonide also improved the scopolamine-induced impairment of memory registration in passive avoidance behavior in mice. The results of this study suggest that it may be possible to use Thomsonide for the treatment of age-related memory impairment and dementia.     

Role for monoaminergic systems in the antidepressant-like effect of ethanol extracts from Hemerocallis citrina

Ethnopharmacological relevance

Hemerocallis citrina, a traditional herbal medicine, has been used for the improvement of emotions in Eastern-Asia countries.

Aim of the study

Herein, we explored the antidepressant-like effect and its monoaminergic mechanism of the ethanol extracts from Hemerocallis citrina (HCE).

Materials and methods

Effect of HCE (90, 180 and 360 mg/kg, p.o.) on the immobility time was assessed in the mouse forced swim test (FST) and tail suspension test (TST), and locomotor activity was evaluated in the open-field test (OFT). Additionally, the monoamine neurotransmitters serotonin (5-HT), noradrenaline (NA) and dopamine (DA) levels involved in the antidepressant-like effect of HCE were also measured in the mice brain regions of frontal cortex and hippocampus.

Results

HCE (90, 180 and 360 mg/kg, p.o.) administration significantly reduced the immobility time in both the FST and TST without accompanying changes in locomotor activity in the OFT. The pretreatment of mice with WAY 100635 (0.1 mg/kg, s.c., a 5-HT_1A receptor antagonist), cyproheptadine (3 mg/kg, i.p., a 5-HT₂ receptor antagonist), prazosin (62.5 μg/kg, i.p., an α₁-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an α₂-adrenoceptor antagonist), propranolol (5 mg/kg, i.p., a β-adrenoceptor antagonist) or sulpiride (50 mg/kg, i.p., a dopamine D₂ receptor antagonist), but not SCH23390 (0.05 mg/kg, s.c., a dopamine D₁ receptor antagonist) prevented the antidepressant-like effect of HCE (360 mg/kg, p.o.) in the TST. In addition, HCE enhanced 5-HT and NA levels in the frontal cortex and hippocampus as well as elevated DA levels in the frontal cortex.

Conclusion

The results indicate that the antidepressant-like effect of HCE is dependent on the serotonergic (5-HT_1A and 5-HT₂ receptors), noradrenergic (α₁-, α₂- and β-adrenoceptors) and dopaminergic (D₂ receptor) systems as well as the elevation of 5-HT, NA and DA levels in the mouse brain.     

Antidepressant activity of standardised extract of Marsilea minuta Linn

AIM OF THE STUDY: Marsilea minuta Linn. (Marsileaceae) has been referred in Indian traditional medicine system (Ayurveda) for the treatment of insomnia and other mental disorders. Marsiline isolated from Marsilea minuta was reported to have sedative and anticonvulsant property. The ethanol extract of Marsilea minuta was standardised for marsiline (1.15%, w/w) and studied for its antidepressant activity. MATERIALS AND METHODS: Antidepressant activity was studied using forced swimming test (FST), tail suspension test (TST), learned helplessness test (LHT) and 5-hydroxytryptophan (5-HTP) induced head twitches response in rodents. Standardised extract of Marsilea minuta in doses of 100, 200 and 400 mg/kg/day were administered orally for three consecutive days and evaluated on day 3, 1h after the last dose treatment. Imipramine (15 mg/kg/day, i.p.) was used as the standard drug. Neurochemical mechanism of antidepressant activity was elucidated by using radioligand receptor binding assays for 5-HT2A and benzodiazepine receptors in rat frontal cortex. RESULTS: Immobility time in FST and TST was significantly (P<0.05) reduced by ethanol extract of Marsilea minuta treated animals. A decrease in number of escape failures in LHT was also observed in Marsilea minuta treated rats. Head twitch response induced by 5-HTP was significantly attenuated by Marsilea minuta (400 mg/kg, p.o.) and imipramine showing the involvement of serotonergic system. This effect was corroborated with radioligand receptor binding study where Marsilea minuta (400 mg/kg, p.o.) significantly (P<0.05) down regulated 5-HT2A receptor in frontal cortex, whereas, no marked effect was observed for benzodiazepine receptor. CONCLUSION: The antidepressant effect exhibited by Marsilea minuta extract may be due to its effect on 5-HT2A density in rat frontal cortex.     

Anxiolytic effects of the aqueous extract of Uncaria rhynchophylla

The purpose of this study was to characterize the putative anxiolytic-like effects of the aqueous extract of hooks with stem of Uncaria rhynchophylla using the elevated plus maze (EPM) and the hole-board apparatus in rats and mice. Control rats were treated with an equal volume of saline, and positive control rats with buspirone (1 mg/kg). Single or repeated treatments of the aqueous extract of Uncaria rhynchophylla (200 mg/kg/day, p.o.) for 7 days significantly increased the time-spent and entries into open arms of the EPM, and reduced the time-spent and entries into the closed arms versus saline controls (P<0.05). However, no changes in spontaneous locomotor activity or myorelaxant effects were observed versus saline controls. In the hole-board test, repeated treatment with the aqueous extract of Uncaria rhynchophylla (100 or 200 mg/kg/day, p.o.) significantly increased the number of head-dips (P<0.05). In addition, the anxiolytic-like effects of Uncaria rhynchophylla extract as assessed using the EPM test were abolished by WAY 100635 (0.3 mg/kg, i.p.), a 5-HT(1A) receptor antagonist. These results suggest that Uncaria rhynchophylla is an effective anxiolytic agent, and acts via the serotonergic nervous system.     

Effect of Evolvulus alsinoides Linn. on learning behavior and memory enhancement activity in rodents

In the Ayurvedic system of medicine, the whole herb of ‘Shankhpushpi’ has been employed clinically for centuries for its memory potentiating, anxiolytic and tranquilizing properties. The present study was undertaken to investigate the effects of Evolvulus alsinoides (EA), considered as Shankhpushpi on learning and memory in rodents. Nootropic activity using Cook and Weidley's pole climbing apparatus, passive avoidance paradigms and active avoidance tests were used to test learning and memory. The ethanol extract of EA and its ethyl acetate and aqueous fractions were evaluated for their memory enhancing properties. Two doses (100 and 200 mg/kg p.o.) of the ethanol extract and ethyl acetate and aqueous fractions were administered in separate groups of animals. Both doses of all the extracts of EA significantly improved learning and memory in rats. Furthermore, these doses significantly reversed the amnesia induced by scopolamine (0.3 mg/kg i.p.). Nootropic activity was compared using piracetam as the standard. EA also exhibited potent memory enhancing effects in the step‐down and shuttle‐box avoidance paradigms. Copyright © 2009 John Wiley & Sons, Ltd.     

Psychopharmacological screening of Pfaffia glomerata Spreng. (Amarathanceae) in rodents

The alcoholic extract of Pfaffia glomerata roots (100, 500, 1000 mg/kg, intraperitoneally (i.p.), and 500, 1000, 1500 mg/kg, per os) was studied in several behavioral animal models for the evaluation of central activity: open field, barbiturate sleeping time, pentilenotetrazole (PTZ)-induced convulsions, elevated plus-maze, step-down inhibitory avoidance and forced swimming test. The acute treatment (500 mg/kg, i.p.) interfered with the open-field habituation, decreased sleep latency and increased barbiturate-induced sleeping time, protected partially the animals of PTZ-induced convulsions, decreased the memory retention in step-down inhibitory avoidance, and did not have an important effect in the elevated plus-maze test and forced swimming test. The same extract at 1000 mg/kg per os did not cause any effect in barbiturate sleeping time and pentilenotetrazole-induced convulsions models. Thus, the effect on the memory was deeper evaluated in the step-down inhibitory avoidance task. When administered by intraperitoneal route, the extract showed a dose-dependent effect causing full amnesia at 1000 mg/kg. On the other hand, when it was given by oral route at 500, 1000 and 1500 mg/kg, no influence on the memory retention was observed. These results suggest that the alcoholic extract of P. glomerata roots presents different effects depending on the route of administration: by i.p route, it seems to be a central nervous system depressant agent; by oral route, it seems to be ineffective, at least in the tested doses.     

Central Nervous System Activities of Hypericum origanifolium Extract via GABAergic and Opioidergic Mechanisms

Pharmacological effects of hydroalcoholic extract prepared from Hypericum origanifolium Willd. (Guttiferae) on behavioral parameters and pain perceptions of mice were investigated in this study. Depression, anxiety, spontaneous locomotor activity, and motor coordination parameters of mice were assessed by modified forced swimming, hole board, activity cage, and rota‐rod tests, respectively. In addition, antinociceptive effect was evaluated by performing hot‐plate, tail‐clip, and formalin tests. Reboxetine (20 mg/kg), diazepam (1 mg/kg), and morphine (10 mg/kg) were used as reference antidepressant, anxiolytic, and analgesic drugs, respectively. Phytochemical analyses exhibited that chlorogenic acid (2317.12 ppm) and rutin (2108.79 ppm) were the main phenolic compounds in the H. origanifolium extract. The extract (50, 100, and 250 mg/kg) induced significant antidepressant, anxiolytic, and antinociceptive activities following the acute administrations. Anxiolytic effect was antagonized by flumazenil (a benzodiazepine receptor antagonist, 2.5 mg/kg, i.p.) pre‐treatment, which indicated the participation of GABA(A)‐benzodiazepine receptor complex in the activity. Moreover, centrally and peripherally mediated antinociception reversed by naloxone (a non‐selective opioid receptor antagonist, 5 mg/kg, i.p.) pre‐treatment, indicating the involvement of opioid system in the pharmacological action. These findings are the first to indicate the pharmacological effects of the H. origanifolium extract on the emotional state and pain perceptions of mice. Copyright © 2012 John Wiley & Sons, Ltd.     

Schizandrin reverses memory impairment in rats

The present study investigated the effect of schizandrin, a component of the fruit of Schizandra chinesis Baill (Fructus Schizandrae), on memory impairment in rats. Scopolamine (0.5 mg/kg, i.p.), a non-selective muscarinic receptor antagonist, markedly impaired spatial memory in an eight-arm radial maze. A higher dose of scopolamine (3 mg/kg, i.p.) also impaired the passive avoidance response. Schizandrin (1 and 10 mg/kg, p.o.) significantly reversed the scopolamine-induced impairment of spatial memory. Similarly, schizandrin (1 mg/kg, p.o.) significantly reversed the scopolamine-induced impairment of the passive avoidance response. Moreover, in mice, schizandrin (1 and 10 mg/kg, p.o.) enhanced tremors induced by oxotremorine, a muscarinic M(1) receptor agonist. Taken together these findings suggest that schizandrin reverses scopolamine-induced memory impairment, in part, by enhancing cholinergic function, and that schizandrin might be useful for treating memory deficits.     

Nootropic-like effect of ashwagandha (Withania somnifera L.) in mice

Ashwagandha (Withania somnifera L.) root extract (50, 100 and 200 mg/kg; orally) improved retention of a passive avoidance task in a step-down paradigm in mice. Ashwagandha (50, 100 and 200 mg/kg; orally) also reversed the scopolamine (0.3 mg/kg)-induced disruption of acquisition and retention and attenuated the amnesia produced by acute treatment with electroconvulsive shock (ECS), immediately after training. Chronic treatment with ECS, for 6 successive days at 24 h intervals, disrupted memory consolidation on day 7. Daily administration of ashwagandha for 6 days significantly improved memory consolidation in mice receiving chronic ECS treatment. Ashwagandha, administered on day 7, also attenuated the disruption of memory consolidation produced by chronic treatment with ECS. On the elevated plus-maze, ashwagandha reversed the scopolamine (0.3 mg/kg)-induced delay in transfer latency on day 1. On the basis of these findings, it is suggested that ashwagandha exhibits a nootropic-like effect in naive and amnesic mice.     

Effects of an Atractylodes lancea rhizome extract and a volatile component β-eudesmol on gastrointestinal motility in mice

Aim of the study

The rhizomes of Atractylodes lancea DC (Compositae) are used clinically to treat gastrointestinal symptoms, including functional dyspepsia and gastroparesis, in China and Japan, but their influence and mechanism on gastrointestinal motility are not yet proven in detail.

Materials and methods

This study examined the effects of an Atractylodes lancea extract, and isolated β-eudesmol, on gastric emptying and small intestinal motility in atropine-, dopamine-, and 5-hydroxytryptamine (5-HT)-treated mice.

Results and conclusions

The extract (500 or 1000 mg/kg) and β-eudesmol (50 or 100 mg/kg), as well as itopride hydrochloride (a dopamine D₂ receptor antagonist, 10 or 50 mg/kg), stimulated small intestinal motility in normal mice. They inhibited reductions in gastric emptying and gastrointestinal motility induced by dopamine (1 mg/kg, intraperitoneal injection, ip). The extract (1000 mg/kg) and β-eudesmol (100 mg/kg) inhibited the atropine-induced decrease in small intestinal motility, but not gastric emptying. Furthermore, the extract (500 or 1000 mg/kg) and β-eudesmol (25, 50, or 100 mg/kg) inhibited reductions in gastric emptying and small intestinal motility caused by 5-HT (4 mg/kg, ip) or the 5-HT₃ receptor agonist 1-(3-chlorophenyl) biguanide (0.5 mg/kg, ip), but not a 5-HT_2C receptor agonist. These findings suggest that the extract of Atractylodes lancea and β-eudesmol may stimulate gastric emptying or small intestinal motility by inhibiting the dopamine D₂ receptor and 5-HT₃ receptor.