Scopolamine Group Research Articles

Nootropic and Neuroprotective Effects of Dichrocephala integrifolia on Scopolamine Mouse Model of Alzheimer's Disease.

Alzheimer’s disease the most common form of dementia in the elderly is a neurodegenerative disease that affects 44 millions of people worldwide. The first treatments against Alzheimer’s disease are acetylcholinesterase inhibitors; however, these medications are associated with many side effects. Dichrocephala integrifolia is a traditional herb widely used by indigenous population of Cameroon to treat and prevent Alzheimer’s disease and for memory improvement. In this study, we evaluated the effect of the decoction prepared from leaves of D. integrifolia, on scopolamine-induced memory impairment in mice. Seven groups of six animals were used. The first two groups received distilled water for the distilled water and scopolamine groups. The four test groups received one of the four doses of the decoction of the plant (35, 87.5, 175 or 350 mg/kg p.o.) and the positive control group received tacrine (10 mg/kg), a cholinesterase inhibitor used in the treatment of Alzheimer’s disease, during 10 consecutive days. Scopolamine (1 mg/kg), a cholinergic receptor blocker, administered 30 min after treatments, was used to induce memory impairment to all groups except the distilled water group on day 10 of drug treatment. The behavioral paradigms used to evaluate the effects of the treatment were the elevated plus maze for learning and memory, Y maze for spatial short-term memory, the novel object recognition for recognition memory and Morris water maze for the evaluation of spatial long-term memory. After behavioral tests, animals were sacrificed and brains of a subset were used for the assessment of some biomarkers of oxidative stress (malondialdehyde and reduced glutathione levels) and for the evaluation of the acetylcholinesterase activity. From the remaining subset brains, histopathological analysis was performed. The results of this study showed that, D. integrifolia at the doses of 87.5 and 350 mg/kg significantly (p < 0.01) improved spatial short-term and long-term memory, by increasing the percentage of spontaneous alternation in the Y maze and reducing the escape latency in the Morris water maze. Furthermore, the results of histopathological evaluation showed that D. integrifolia attenuated the neuronal death in the hippocampus induced by scopolamine. The main finding of this work is that D. integrifolia improves learning capacities and counteracts the memory impairment induced by scopolamine. Thus, D. integrifolia can be a promising plant resource for the management of Alzheimer’s disease and memory loss.

Evaluation of cognition enhancing activity of pioglitazone in albino mice

Background: Worldwide, 47.5 million people have dementia, with just over half (58%) living in low- and middle-income countries. Every year, there are 7.7 million new cases. The estimated proportion of the general population aged 60 and over with dementia at a given time is between 5 to 8 per 100 people. The total number of people with dementia is projected to be 75.6 million in 2030 and almost triple by 2050 to 135.5 million.Methods: All animals were allowed to acclimatize with laboratory conditions at least two weeks before starting the experiment and they were maintained under the same condition throughout the experiment. They were given food and water ad libitum. The experiments were performed as per the Committee for the Purpose of Control and Supervision on Experiments on Animals (CPCSEA) guidelines. The animals were subjected to experimentation between 0900-1600 hours in noise free atmosphere with ambient temperature 23-300ºC.Results: The Pioglitazone treated groups showed statistically significant results in the SDL when compared to the control group (p&lt;0.01 on both days) and the scopolamine group (p&lt;0.01 on both days) on both acquisition day and retention day.Conclusions: There was no significant difference in SDL in standard and Pioglitazone treated groups on both acquisition day and retention day.

Walnut supplementation reverses the scopolamine-induced memory impairment by restoration of cholinergic function via mitigating oxidative stress in rats: a potential therapeutic intervention for age related neurodegenerative disorders.

The brain is highly susceptible to the damaging effects of oxidative reactive species. The free radicals which are produced as a consequence of aerobic respiration can cause cumulative oxygen damage which may lead to age-related neurodegeneration. Scopolamine, the anti-muscarinic agent, induces amnesia and oxidative stress similar to that observed in the older age. Studies suggest that antioxidants derived from plant products may provide protection against oxidative stress. Therefore, the present study was designed to investigate the attenuation of scopolamine-induced memory impairment and oxidative stress by walnut supplementation in rats. Rats in test group were administrated with walnut suspension (400mg/kg/day) for four weeks. Both control and walnut-treated rats were then divided into saline and scopolamine-treated groups. Rats in the scopolamine group were injected with scopolamine (0.5mg/kg dissolved in saline) five minutes before the start of each memory test. Memory was assessed by elevated plus maze (EPM), Morris water maze (MWM), and novel object recognition task (NOR) followed by estimation of regional acetylcholine levels and acetylcholinesterase activity. In the next phase, brain oxidative status was determined by assaying lipid peroxidation, and measuring superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. Results showed that scopolamine-treatment impaired memory function, caused cholinergic dysfunction, and induced oxidative stress in rats compared to that saline-treated controls. These impairments were significantly restored by pre-administration of walnut. This study demonstrates that antioxidant properties of walnut may provide augmented effects on cholinergic function by reducing oxidative stress and thus improving memory performance.

Neuroprotective Effect of Green Synthesized Iron Oxide Nanoparticles Using Aqueous Extract of Convolvulus Pluricaulis Plant in The Management of Alzheimer’s Disease

To evaluate the neuroprotective effect of green synthesized iron oxide nanoparticles using aqueous extract of whole plant of Convolvulus pluricaulis (CPIO) in scopolamine induced amnesia model. CPIO were orally tested at the dose of 100 mg/kg, 200 mg/kg and 400 mg/kg for neuroprotective effect in scopolamine induced amnesia mice. In addition, neurobehavioral studies were carried out using elevated plus maze, Morris water maze to evaluate learning and memory in mice in normal and scopolamine induced amnesia mice. CPIO 400 mg/kg showed a significant improvement in learning and memory in the normal and scopolamine induced amnesia mice in exteroceptive models. Significant differences were observed in lipid peroxidation, catalase and acetylcholinesterase by 400 mg/kg of CPIO treated amnesic animals, when compared with untreated and scopolamine group animals. The highest dose of CPIO exhibited significant neuroprotective effect in normal and scopolamine induced amnesia mice. They also showed significant improvement in learning and memory in exteroceptive and interoceptive models and so might be of value in Alzheimer’s treatment.

Subchronic Amitriptyline Influences Open-field Behaviours and Spontaneous Working-memory in Healthy Mice

Objective: We assessed the effects of amitriptyline on open-field locomotion, stereotypic behaviours and spatial working-memory in healthy mice. Method: Five groups of mice were administered vehicle (distilled water), scopolamine (2 mg/kg), or one of three doses of amitriptyline (5, 10 and 15 mg/kg) for 21 days. Behaviours were assessed after the first and final dose of treatment. Result: Administration of the first dose of amitriptyline was associated with enhanced open-field horizontal locomotion, rearing and grooming; with repeated administration, there was suppression of horizontal locomotion and rearing. A dose-related decrease in Y-maze and radial-arm maze spatial working-memory was also observed after repeated administration. Compared to scopolamine, amitriptyline was associated with a significant reduction in open-field behaviours, but a significantly-higher spatial working-memory score. Conclusion: Repeated administration of amitriptyline in healthy mice was associated with suppression of locomotion and grooming; working-memory deficits were also observed. However, working-memory task performance is significantly better than the scopolamine group.

A comparative study of American ginseng (spp. Panax quinquefolius) and Donepezil on working memory in rats using scopolamine induced disruption of memory

Background: Treatment of Alzheimer’s disease (AD) includes acetylcholinesterase inhibitors like Donepezil. American ginseng has been postulated to enhance learning and memory owing to its antiapoptotic activity as well as inhibition of formation of β amyloid plaque. Scarce data is available on effect of combination of these two drugs. Hence, we have conducted this study to evaluate the same. Aim and objectives of the study were to evaluate the role of American ginseng on working memory in rats and to compare the effect of American ginseng with Donepezil on working memory in rats.Methods: Sprague-Dawley rats of either sex, weighing 150-200g were used and obtained from animal house of Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pimpri, Pune. To study the effects of the drugs on working memory in rats, they were trained for conditioned avoidance response (CAR) using Cook's pole climbing apparatus. The method of Fellow and Cook was used.Results: In the group C (i.e. the control group), 50% of rats showed the retention of CAR. In the group S (i.e. only scopolamine group), only 20% of rats showed the retention of CAR. In the group S+AG (i.e. scopolamine and American ginseng), 60% of rats showed the retention of CAR. In the group S+ D (i.e. scopolamine and Donepezil) 70% of rats showed retention of CAR. In the group S+D+AG (i.e. the combination group of scopolamine, Donepezil and American ginseng), 80% of rats showed the retention of CAR.Conclusions: From this study we can conclude that American ginseng and Donepezil have comparable effects in retention of working memory. The combination of American ginseng and Donepezil can have additive effect on the retention of working memory.

Beneficial effect of commercial Rhodiola extract in rats with scopolamine-induced memory impairment on active avoidance

Rhodiola rosea L., family Crassulaceae also known as Golden Root or Arctic root is one of the most widely used medicinal plants with effect on cognitive dysfunction, psychological stress and depression. The aim of the study was to examine the effect of a standardized commercial Rhodiola extract on learning and memory processes in naive rats as well as its effects in rats with scopolamine-induced memory impairment. Materials and methodsSixty male Wistar rats were used in the study. The experiment was conducted in two series - on naive rats and on rats with scopolamine-induced model of impaired memory. The active avoidance test was performed in an automatic conventional shuttle box set-up. The criteria used were the number of conditional stimuli (avoidances), the number of unconditioned stimuli (escapes) as well as the number of intertrial crossings. ResultsThe chemical fingerprinting of the standardized commercial Rhodiola extract was performed by means of nuclear magnetic resonance (NMR). Naive rats treated with standardized Rhodiola extract increased the number of avoidances during the learning session and memory retention test compared to the controls. Rats with scopolamine-induced memory impairment treated with Rhodiola extract showed an increase in the number of avoidances during the learning session and on the memory tests compared to the scopolamine group. The other two parameters were not changed in rats treated with the extract of Rhodiola in the two series. ConclusionIt was found that the studied Rhodiola extract exerts a beneficial effect on learning and memory processes in naive rats and rats with scopolamine-induced memory impairment. The observed effect is probably due to multiple underlying mechanisms including its modulating effect on acetylcholine levels in the brain and MAO-inhibitory activity leading to stimulation of the monoamines‘ neurotransmission. In addition the pronounced stress-protective properties of Rhodiola rosea L. could also play a role in the improvement of cognitive functions.

Benzoate fraction from Gentiana rigescens Franch alleviates scopolamine-induced impaired memory in mice model in vivo

Ethnopharmacological relevanceG. rigescens Franch (Long Dan Cao in Chinese) is a well-known TCM herb. It is clinically used with other drugs for the treatment of brain diseases such as epilepsy, postherpetic neuralgia in China. Aim of studyIn our previous study, the 11 dihydroxybenzoates compounds with NGF mimicking activity from G. rigescens Franch were found. In the present study, the neurogenesis and neuroprotection of a mixture of benzoates ( n-GS) were investigated in animal level. Materials and methodsThe NGF mimicking activity of n-GS from G. rigescens Franch was examined in PC12 cells. The neurogenesis effects of n-GS were investigated in ICR mice with 5-bromo-2-deoxyuridine (BrdU) and neuronal neclei (NeuN) double immunostaining. Furthermore, the neuroprotection effects of n-GS on the memory in a scopolamine (SCO)-induced mouse model were evaluated with animal behavior tests. ResultsThe NGF-mimicking function and neurogenesis of n-GS were observed in PC12 cells and in normal mice. Subsequently, we investigated the effects of n-GS on the memory in a SCO-induced mouse model. In Y-maze test, SCO significantly lowered the alternation. This finding was reversed by n-GS and donepezil (DONE). SCO significantly impaired the mice's performance in novel object recognition (NOR) and Morris water maze (MWM) tests. The time spent to explore the novel object was longer in the n-GS- and DONE-treated groups than in the SCO control group. In the MWM test, the escape latency of n-GS- and DONE-treated groups was shorter than that of the SCO control group. Mechanism study showed that SCO significantly reduced superoxide dismutase (SOD) but increased the activities of acetylcholinesterase (AChE) and the levels of malondialdehyde (MDA) in the hippocampus and cerebral cortex, which all can be improved by n-GS and DONE. Additionally, the phosphorylation of type 1 insulin-like growth factor (IGF-1) receptor, extracellular signal-regulated kinase (ERK), and cAMP responsive element-binding (CREB) protein in the hippocampus was significantly up-regulated in the treatment group compared with that in the SCO group. Conclusionsn-GS could alleviate impaired memory of the SCO-induced mice model by inhibiting AChE activity and oxidative stress, and regulating the IGF-1R/ERK signaling pathway.

Investigation on Learning and Memory Enhancing activity of Essential Oil inAlbizia julibrissin Flowers in Experimental Mice

Two doses (100 mg/kg and 200 mg/kg p.o) of the Albizia julibrissin essential oil (AJEO) were subjected for the evaluation of learning and memory enhancing activity against amnesia induced by scopolamine (0.4mg/kg, i.p) in young mice. Piracetam (400 mg/kg i.p) was served as standard in both the models. Biochemical parameter like Anticholinesterase activity was evaluated. Both the lower (100mg/kg) and higher dose (200mg/kg) of AJEO has shown dose dependent significant decrease in Transfer latency (TL) by EPM and decrease in AChE activity in brain estimation which in terms indicate improved learning and memory when compared with scopolamine group. Sub-acute treatment (long term) was more significant than acute treatment (short term) on learning and memory enhancing activity.

Effects of β adrenergic receptor blocker carvedilol and cholinergic receptor blocker scopolamine on biological behaviors of prostate cancer in mice

Objective To investigate the effects of β adrenergic receptor blocker carvedilol and cholinergic receptor blocker scopolamine on the biological behaviors of prostate cancer in C57BL/6 mice. Methods From June 2014 to November 2014, sixty male C57BL/6 mice, 10 weeks old, were injected with RM-1 cells (0.5×106) into bilateral dorsal prostate capsules of each mice by microsyringe and were randomly divided into three groups, including carvedilol group (K), scopolamine group (D) and saline group (N) after modeling. In K group, the carvedilol (10 mg/kg) was given to mice through gastric tube. The normal saline was given to them by subcutaneous injection. In D group, the normal saline was given to mice through gastric tube. Meanwhile, the scopolamine (1 mg/kg) was injected subcutaneously. In N group, daily normal saline was given by through gastric tube and subcutaneous injection. At the seventh day of postoperation, five mouse were sacrificed in each group every three days to observe the local growth, invasion and metastasis of prostate cancer to pelvic nodes and liver. Immunohistochemical determination of prostate tumor was made by TH staining and VAChT staining in each group. Results The volume of the prostate cancer was gradually increased in three groups. There was no statistical difference of prostate volume among three groups on the day 7 and 10 post-operatively (all P>0.05). The prostate volume of K group, D group and N group on the day 13 were 0.05±0.04, 0.18±0.08, 0.14±0.05 cm3, respectively (P 0.05). The AOD of TH and VAChT in prostate cancer of K group, D group and N group on the day 10 were [(0.0114±0.016), (0.114±0.002), (0.059±0.008)] and [(0.025±0.011), (0.0226±0.003), (0.009±0.003)], respectively (P 0.05). Conclusions β adrenergic receptor blocker carvedilol can suppress the growth of prostate cancer and cholinergic receptor blocker scopolamine may can inhibit metastasis of prostate cancer. Key words: Prostatic carcinoma; Mouse; Carvedilol; Scopolamine

Treatment with a muscarinic acetylcholine receptor antagonist impairs the acquisition of conditioned reward learning in rats

The neural mechanisms whereby a reward-associated stimulus gains reinforcing properties and comes to function as a conditioned reward (CR) are not understood. We propose that muscarinic acetylcholine (mACh) receptor stimulation is necessary for this type of learning. Here we tested the hypothesis that mACh receptor antagonism, with scopolamine, would attenuate the acquisition by a food-related stimulus of the capacity to function as a CR. Rats were exposed to 5 pre-exposure sessions during which two levers were present, one producing a light and the other a tone when pressed. This was followed by 3 conditioning sessions in which the levers were absent and the rats were presented with 30 light-food pairings delivered randomly. In the test session, the levers were present and presses on both levers were recorded. Different groups of rats received intraperitoneal injections of scopolamine (0, 0.375, 0.75 and 1mg/kg) either prior to each conditioning session or prior to the test session. All groups showed significantly greater responding on the light lever in the test compared to the pre-exposure sessions, demonstrating the CR effect. In animals treated prior to conditioning the scopolamine groups pressed significantly less on the light lever than the vehicle group. In animals treated prior to the test the increased lever pressing for light was similar for all groups. These data suggest that scopolamine impaired the acquisition of CR but not its expression. The results support the hypothesis that mACh receptor stimulation is important for the acquisition by reward-associated stimuli of the ability to function as CRs.

Vinpocetine Improves Scopolamine Induced Learning and Memory Dysfunction in C57 BL/6J Mice.

Vinpocetine is an inhibitor of phosphodiesterase type 1 (PDE1), which has been used for treating stroke for over 40 years. However, according to current clinical dosage and treatment period, its direct effect on memory is unclear. In this study, we investigated whether vinpocetine could reverse the scopolamine (SCO)-induced cognitive deficits in animals. Behavioral experiments, including open field, Y-maze, and fear conditioning tests were used to determine the possible role of vinpocetine on scopolamine-induced memory dysfunction. In the open field and Y-maze tests, there were significant differences between the control (CON) group and SCO group. Vinpocetine (4 mg/kg) administration for consecutive 28 d significantly improved the scopolamine-induced memory dysfunction. In the fear conditioning test, vinpocetine (2, 4 mg/kg) administration had certain beneficial effect on emotional memory. Our results suggest that vinpocetine could improve cognitive function in memory deficient mice and high clinic dosage might be better.

Repeated administration of almonds increases brain acetylcholine levels and enhances memory function in healthy rats while attenuates memory deficits in animal model of amnesia.

Dietary nutrients may play a vital role in protecting the brain from age-related memory dysfunction and neurodegenerative diseases. Tree nuts including almonds have shown potential to combat age-associated brain dysfunction. These nuts are an important source of essential nutrients, such as tocopherol, folate, mono- and poly-unsaturated fatty acids, and polyphenols. These components have shown promise as possible dietary supplements to prevent or delay the onset of age-associated cognitive dysfunction. This study investigated possible protective potential of almond against scopolamine induced amnesia in rats. The present study also investigated a role of acetylcholine in almond induced memory enhancement. Rats in test group were orally administrated with almond suspension (400 mg/kg/day) for four weeks. Both control and almond-treated rats were then divided into saline and scopolamine injected groups. Rats in the scopolamine group were injected with scopolamine (0.5 mg/kg) five minutes before the start of each memory test. Memory was assessed by elevated plus maze (EPM), Morris water maze (MWM) and novel object recognition (NOR) task. Cholinergic function was determined in terms of hippocampal and frontal cortical acetylcholine content and acetylcholinesterase activity. Results of the present study suggest that almond administration for 28 days significantly improved memory retention. This memory enhancing effect of almond was also observed in scopolamine induced amnesia model. Present study also suggests a role of acetylcholine in the attenuation of scopolamine induced amnesia by almond.

Effects of Matricaria chamomilla extract on motor coordination impairment induced by scopolamine in rats

ObjectiveTo evaluate the effect of ethanolic extract of chamomile on balance and motor learning in rats receiving scopolamine and intact rats. MethodsFourty-two rats were divided into 6 groups (n = 7). Control group received distilled water. Rats in Group 2 were given 1 mg/kg scopolamine. Groups 3 and 4 received chamomile extract 200 mg/kg and 500 mg/kg, respectively, and scopolamine simultaneously for 20 days. Intact groups (Groups 5 and 6) only received chamomile extract 200 mg/kg and 500 mg/kg, respectively. Motor coordination of rats was assessed with rotarod apparatus. ResultsAccording to the obtained results, compared with the control group, scopolamine significantly decreased time spent on rotarod performance (P < 0.001). Compared with scopolamine group, the strength and staying on rotarod apparatus in Group 3 significantly increased (P < 0.05). The results of this research showed that intact groups that received only chamomile extract at doses of 200 mg/kg and 500 mg/kg significantly increased time spent on rotarod, compared with scopolamine group (P < 0.001). ConclusionsThe results of this study indicated the high antioxidant property and protective effect of chamomile extract on motor coordination in the groups that received scopolamine.

Impact of spasmolytic on polyp and adenoma detection during colonoscopy: a meta-analysis

To investigate the impact of intestinal spasmolytic on colon polyps and adenoma detection rate during colonoscopy. Literatures related to the effect of intestinal spasmolytic on colon polyp or adenoma detection rate were retrieved from PubMed, Medline, EBSCO, High Wire Press, OVID, EMBASE, and the China National Knowledge Articles, etc. published before July 2014. Unified data were extracted by two researchers independently and organized using Jadad scale to evaluate the quality of the enrolled studies through Review manager 5.2 Meta-analysis software. Six articles were enrolled with total 47,509 cases, including 16,867 cases in the scopolamine group and 30,642 cases in the placebo group. Meta analysis showed spasmolytic could increase the detective rate of polyps (OR=1.24, 95% CI:1.19-1.30), adenoma (OR=1.25, 95% CI:1.19-1.30) and high-risk adenoma (OR=1.22, 95% CI:1.16-1.29). Using colonoscopy spasmolytic scopolamine can increase the detection rate of colonic polyp and adenoma.

Effect of Jyotiṣmatī seed oil on spatial and fear memory using scopolamine induced amnesia in mice

Background:Treatment of memory impairment associated with dementia such as Alzheimer's disease is still inadequate and requires development of new drugs.Objective:The objective was to evaluate the memory enhancing effect of Celastrus paniculatus seed oil.Materials and Methods:C. paniculatus seed oil was mixed with equal amount of pure ghee and administered orally to mice in the dose of 200 mg/kg/day. Piracetam was used as a standard nootropic. Elevated plus maze and passive avoidance tests were used as a models to test spatial and fear memory respectively. Scopolamine (3 mg/kg, i.p.), was used as an amnestic agent.Results:Mice receiving C. paniculatus showed significant memory enhancement as compared to scopolamine group. The effect of C. paniculatus and combination of C. paniculatus with piracetam was comparable to that with piracetam alone.Conclusion:The present study demonstrates that C. paniculatus seed oil has memory enhancing effect and hence can be developed as a potential drug in the treatment of dementia.

Extraorbital lacrimal gland excision: a reproducible model of severe aqueous tear-deficient dry eye disease.

The aim of this study was to establish and characterize extraorbital lacrimal gland excision (LGE) as a model of aqueous tear-deficient dry eye disease in mice. Female C57BL/6 mice at 6 to 8 weeks of age were randomized to extraorbital LGE, sham surgery, or scopolamine groups. Mice that underwent extraorbital LGE or sham surgery were housed in the standard vivarium. Scopolamine-treated mice were housed in a controlled environment chamber that allowed for the continuous regulation of airflow (15 L/min), relative humidity (30%), and temperature (21-23°C). Clinical disease severity was assessed over the course of 14 days using the phenol red thread test and corneal fluorescein staining. Real-time polymerase chain reaction was performed to assess corneal mRNA expression of interleukin 1β, tumor necrosis factor α, and matrix metalloproteinase 9. Flow cytometry was used to assess T helper cell frequencies in the conjunctivae and draining lymph nodes. Extraorbital LGE markedly reduced aqueous tear secretion as compared with the sham procedure and induced a more consistent decrease in aqueous tear secretion than was observed in mice that received scopolamine while housed in the controlled environment chamber. Extraorbital LGE significantly increased corneal fluorescein staining scores as compared with those of both the sham surgery and scopolamine-treated groups. Extraorbital LGE significantly increased the corneal expression of interleukin 1β, tumor necrosis factor α, and matrix metalloproteinase 9. Further, extraorbital LGE increased T helper 17-cell frequencies in the conjunctivae and draining lymph nodes. Extraorbital LGE induces aqueous tear-deficient dry eye disease in mice as evidenced by decreased aqueous tear secretion, increased corneal epitheliopathy, and induced ocular surface inflammation and immunity.

Ameliorative effect of rosmarinic acid on scopolamine-induced memory impairment in rats

Rosmarinic acid (RA) is a natural phenol that exerts different biological activities, such as antioxidant activity and neuroprotective effects. In this study, we hypothesized that administration of RA (8, 16, and 32mg/kg, p.o.) for 7 days would effect on scopolamine-induced cognitive dysfunction as an extensively used model of cognitive impairment.The rats were divided into 10 groups. The acquisition trial was done 1h after the last administration of RA. Animals were divided into control, RA (8, 16, and 32mg/kg) and donepezil (2mg/kg) treated controls, scopolamine, RA (8, 16, and 32mg/kg), and donepezil (2mg/kg) treated scopolamine groups. Memory impairment was induced by scopolamine treatment (1mg/kg, i.p.) 30min after the administration of RA, donepezil, or saline.Scopolamine administration caused cognition deficits in the PAL and memory paradigm. While orally RA administration (16 and 32mg/kg) improved learning and memory in control rats, it reversed learning and memory deficits of scopolamine received groups.Administration of RA at the dose of 8mg/kg did not alter cognitive function in control and scopolamine treated groups. The combination of anticholinesterase, neuroprotective, and antioxidant properties of RA may all be responsible for the observed effects. These results indicate the beneficial effects of subchronic RA administration in passive avoidance learning and memory in control rats as well as in a pharmacological model of cholinergic deficit which continue to expand the knowledge base in creating new treatment strategies for cognition deficits and dementia. Of course, further studies are warranted for clinical use of RA in the management of demented subjects.

Protection against brain tissues oxidative damage as a possible mechanism for the beneficial effects of Rosa damascena hydroalcoholic extract on scopolamine induced memory impairment in rats

ObjectivesHypnotic, analgesic, anticonvulsant, and antioxidant effects of Rosa damascena have been reported. This study, investigated the effect of R. damascena hydroalcoholic extract on memory performance in a scopolamine-induced memory impairment model.MethodsThe rats were divided into control group received just saline; scopolamine group was treated by saline for 2 weeks, but was injected by scopolamine 30 minutes before each trial in Morris water maze test; treatment groups (scopolamine + extract 50; Sco + Ext 50) and (scopolamine + extract 250; Sco + Ext 250) were daily treated by 50 and 250 mg/kg of R. damascena extract (2 weeks) and were finally injected by scopolamine before each trial in Morris water maze. The brains were removed for biochemical measurements.ResultsTime latency and path length in the scopolamine group were higher than control (P < 0.01 to <0.001). Both treatment groups showed shorter traveled distance and time latency compared with scopolamine group (P < 0.05 to <0.001). Time spent in target quadrant by scopolamine group was lower than control (P < 0.05), while Sco + Ext 250 group spent longer time in target quadrant than scopolamine group (P < 0.05). Malondialdehyde concentrations in hippocampal and cortical tissues of scopolamine group were higher, while thiol concentrations were lower than control ones (P < 0.001). Treatment by both doses of the extract decreased the malondialdehyde concentration, while increased the thiol concentration (P < 0.05 to <0.001).DiscussionThe results of this study showed that the hydroalcoholic extract of R. damascena prevents scopolamine-induced memory deficits. This finding suggests that memory improvement may be in part due to the antioxidant effects.

The cannabinoid-memory and the Angiotensin-memory paradoxes: Another penrose triangle?

This study aims to evaluate the efficacy of two different drugs in their effects on memory and discrimination learning in a dual, controlled mouse model of amnesia, and to relate the findings to their pharmacokinetic and pharmacodynamics profiles. It also aims at validating a sub-acute scopolamine dose protocol as a model of rodent amnesia, specifically of emotional memory. The Exteroceptive models used include a Y-maze and an Elevated plus Maze (EPM). The Interoceptive models used are two different dose protocols of an amnesic drug, Scopolamine in forty-eight Swiss Albino mice, categorized into an acute and a sub-acute induction division, each of which later received fixed human equivalent doses of two drugs, apart from saline and scopolamine. Each animal was then evaluated for their Novelty Object Recognition (NOR) memory, and visuo-spatial memory, on the Y-maze and the EPM, respectively. The results of the Novelty Preference Test (NPT) and EPM test were analysed using Analysis of Variance. The efficacy of Rimonabant in improving NOR memory was statistically higher than in saline and model control groups, more so in the acute induction. Its efficacy in enhancing visuo-spatial memory was less, although comparable to that on NOR memory. The efficacy of Valsartan was lower than the NOR Recognition Indices of other groups, although insignificant statistically. Sub- acute induction resulted in increased amnesia and anxiety in the Valsartan group on both mazes, the former being comparable to that noted in scopolamine group. Rimonabant is a memory enhancer, in terms of both recognition and spatial memory. Valsartan is a pro-amnesic drug in a sub-acute induction, in which it lead to increased anxiety additionally. Hence, sub acute scopolamine protocol could be a novel model of emotional memory. Though many drawbacks were noted in the study, the drug effects could be explained by pharmacokinetic data and pharmacodynamic effects. This pilot study could be used for correlating the results in human conditions involving memory.