Protective effects of water extract of Morus Nigra L. on 6-Hydroxydopamine induced Parkinson's disease in male rats

Background: Parkinson's disease [PD] is a neurodegenerative disorder characterized by progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Although the etiology of PD is unknown, but major biochemical processes such as oxidative stress is largely described. Angiotensin II activates NADPH depending oxidases and produce superoxides formation. Morus nigra L. extract is an Angiotensin Converting Enzyme [ACE] inhibitor and tested for anti-Parkinsonism effects by biochemical and behavioral evaluations

Materials and Methods: In total 48 Male Wistar rats weighting 200-250 g were divided into 4 groups: [1] Sham [normal saline was injected in the left SNC], [2] Neurotoxin [injection of 6-hydroxydopamine into left SNC], [3] Morus nigra L. aqueous extract and [4] captopril. Morus nigra [10 mg/kg] and captopril [5 mg/kg] were daily-injected i.p. from 6 days before neurotoxin injection, until one day after 6-hydroxydopamine injection. Muscle stiffness and apomorphine test were assessed in 6 rats of any groups after two weeks. Protein oxidation, lipid peroxidation and ACE activity were assessed in brains of 6 rats of each group after 24 hours

Results: Rotation test with apomorphine, Rigidity with Murprogo's test, and lipid peroxidation in sham, captopril and Morus nigra groups were significantly lower than neurotoxin group. Protein oxidation in Morus nigra group was significantly lower than neurotoxin group. Brain ACE activity in neurotoxin, captopril and Morus nigra groups were inhibited

Conclusion: Morus nigra L. extract had protective effects on neuronal oxidation and death and improved signs of PD possibly by ACE inhibition

[Stimulus induced signal improvement in 6-hydroxydopamine model of Hemi- Parkinsonian in rat]

Background and Objectives: Parkinson's disease is a degenerative disorder of the central nervous system. Parkinson's symptoms are mainly motor related symptoms movement. Deep brain stimulation [DBS] has been considered as a last resort in severe cases of the disease. Our objective was to improve the stimulus signal for DBS in a controlled manner

Materials and Methods: In current experiment, Parkinson's model in rats was implemented using 6- hydroxydopamine. Some feedback was needed to improve the parameters of DBS signals. We used electrocardiogram [ECoG] signal feedback. The stimulation and recording were synchronized so it was able to adjust the condition at the real time. In each process the 13 band energy of recorded ECoG was studied and the best option for next stimulation settings was selected

Results: Quasi-statistic stimulation signal showed better result than normal signal. Significant improvement for the stimulus signal parameters was reached

Conclusion: The present method of DBS could be considered as a therapeutic method and could be examined in larger studies in future

Neuroprotective effect of thymoquinone, the nigella sativa bioactive compound, in 6-hydroxydopamine-induced hemi-parkinsonian rat model

Parkinson disease [PD] is the most common movement disorder with progressive degeneration of midbrain dopaminergic neurons for which current treatments afford symptomatic relief with no-prevention of disease progression. Due to the neuroprotective property of the Nigella sativa bioactive compound thymoquinone [TQ], this study was undertaken to evaluate whether TQ could improve behavioral and cellular abnormalities and markers of oxidative stress in an experimental model of early PD in rat. Unilateral intrastriatal 6-hydroxydopamine [6-OHDA]-lesioned rats were daily pretreated p.o. with TQ at doses of 5 and/or 10 mg/Kg three times at an interval of 24 h. After 1 week, apomorphine caused contralateral rotations, a reduction in the number of neurons on the left side of the substantia nigra pars compacta [SNC] was observed, malondialdehyde [MDA] and nitrite level in midbrain homogenate increased and activity of superoxide dismutase [SOD] reduced in the 6-OHDA lesion group. TQ pretreatment significantly improved turning behavior, prevented loss of SNC neurons,and lowered level of MDA. These results suggest that TQ could afford neuroprotection against 6-OHDA neurotoxicity that is partly due to the attenuation of lipid peroxidation and this may provide benefits, along with other therapies, in neurodegenerative disorders including PD

[Effects of kerack used in addict Iranian people on fertility of adult mice]

Infertility is one of the most serious social problems. Illicit drug use can be an important cause of male factor infertility. Kerack which its use is rising up in Iran refers to a high purity street-level heroin [heroin Kerack]. Heroin Kerack used in Iran is an opioid and has harmful effects on body organs. The aim of this study is to investigate the effects of Kerack used in Iran on fertility adult mice. In this study, 25 male mice were divided into five groups [control, sham and three experimental]. Experimental groups of Kerack-dependent mice [received ascending dose of Kerack for seven days] were divided into three categories, experimental I, II and III. Experimental I was given Kerack at a dose of 5 mg/kg, experimental II 35 mg/kg and experimental III 70 mg/kg, intraperitoneally twice a day for a period of 35 days. The sham group received normal saline and lemon juice [2.6 micro l/ml] whilst the control group just received water and food. Mice were then scarified and sperm removed from cauda epididymis were analyzed for sperm count, motility, morphology [normal/abnormal] and viability. Testes were also removed, weighed and processed for light microscopic studies. The results showed that fertility were significantly decreased in addicted mice compared with control groups [P

Endothelium-dependent effect of sesame seed feeding on vascular reactivity of streptozotocin-diabetic rats: underlying mechanisms

Cardiovascular disorders continue to constitute major causes of morbidity and mortality in diabetic patients. In this study, the effect of chronic administration of sesame [Sesamum indicum L] seed feeding was studied on aortic reactivity of streptozotocin [STZ]-diabetic rats. Male diabetic rats received sesame seed-mixed food at weight ratios of 3% and 6% for 7 weeks, one week after diabetes induction. Contractile responses to KCl and phenylephrine [PE] and relaxation response to acetylcholine [ACh] and sodium nitroprusside [SNP] were obtained from aortic rings. Maximum contractile response of endothelium-intact rings to PE was significantly lower in sesame-treated diabetic rats [at a ratio of 6%] relative to untreated diabetics and endothelium removal abolished this difference. Endothelium-dependent relaxation to ACh was also significantly higher in sesame-treated diabetic rats [at a ratio of 6%] as compared to diabetic rats and pretreatment of rings with nitric oxide synthase inhibitor, N[G]-nitro-l-arginine methyl ester [L-NAME] significantly attenuated the observed response. Two-month diabetes also resulted in an elevation of malondialdehyde [MDA] and decreased superoxide dismutase [SOD] activity and sesame treatment significantly reversed the increased MDA content and restored activity of SOD. We thus conclude that chronic treatment of diabetic rats with sesame seed could in a dose- manner prevent some abnormal changes in vascular reactivity through nitric oxide and via attenuation of oxidative stress in aortic tissue and endothelium integrity is necessary for this beneficial effect

Antinociceptive effect of curcumin, an effective constituent of turmeric, in diabetic rats and evaluation of the involvement of lipid peroxidation

This study was designed to investigate the antinociceptive effect of curcumin in diabetic rats by using the formalin and hot tail immersion tests. Wistar rats were divided into the following six groups: control; curcumin-treated control [50 mg/kg]; diabetic; sodium salicylate [SS]-treated diabetic; and two curcumin-treated diabetic groups [10 and 50 mg/kg]. Curcumin was administered seven days after streptozotocin injection for a total of five weeks. High-dose curcumin treatment of diabetic rats reduced the pain score in both acute and chronic phases of the formalin test [p<0.05]. SS-treated diabetic rats had a reduction in pain score only in the chronic phase of the formalin test [p<0.05]. In the hot tail immersion test, diabetic rats showed a significant reduction in tail flick latency compared to the control group [p<0.01]. High-dose curcumin treated diabetic rats showed significantly increased latency relative to untreated diabetic rats [p<0.05]. Diabetic rats also showed a significant increase in the tissue level of malondialdehyde [MDA; p<0.01]. High-dose curcumin treated diabetic rats had a significantly reduced level of MDA [p<0.05]. Chronic administration of curcumin could attenuate the nociceptive score in both the acute and chronic phases of the formalin test in a streptozotocin-induced experimental model of diabetes mellitus and increase thermal pain threshold. The beneficial effect of curcumin is partly attributed to attenuation of lipid peroxidation in the periphery

Antiepileptic effect of vitamin E on kainic acid-induced temporal lobe epilepsy in rats

Epilepsy is a chronic neurological disease with the prevalence of around one percent. Despite the introductions of several anti-epileptic drugs, around 1/3 of epileptic patients are resistant to the anti-epileptic medications. Considering the evidence regarding the anti-oxidant action of Vitamin E and its beneficiary effect in the treatment of epilepsy, we investigated the anti-convulsive effect of Vitamin E in a rat model of kainic acid-induced epilepsy. Forty male rats were divided to five groups [sham, Vit E, epileptic, epileptic treated with Vit E and epileptic treated with valproic acid]. Epilepsy was induced by intra hippocampal injection of 4 microgram of kainic acid. Rats receiving daily intraperitoneal injections of Vit E [100 mg/kg] or valproic acid [200 mg/kg] in the week preceding the surgery. Intensity of epileptic convulsions was graded using Racine's criteria. No convulsions were observed in the sham-Vit E groups. Widespread convulsions were observed in the kainic acid-treated group. Intensity of convulsions were significantly reduced in the epileptic rats receiving either Vit E or valproic acid [P < 0.05 and P < 0.01, respectively]. Pre-treatment with Vit E decreases the convulsion intensity in kainic acid-induced epilepsy in rats

effect of alpha-lipoic acid on learning and memory deficit in a rat model of temporal lobe epilepsy

Epilepsy is a chronic neurological disorder in which patients experience spontaneous recurrent seizures and deficiency in learning and memory. Although the most commonly recommended therapy is drug treatment, some patients do not achieve adequate control of their seizures on existing drugs. New medications with novel mechanisms of action are needed to help those patients whose seizures are resistant to currently-available drugs. While alphalipoic acid as a antioxidant has some neuroprotective properties, but this action has not been investigated in models of epilepsy. Therefore, the protective effect of pretreatment with alpha-lipoic acid was evaluated in experimental model of temporal lobe epilepsy in male rats. In the present study, Wistar male rats were injected intrahippocampally with 0.9% saline[Sham-operated group], kainic acid[4 micro g] alone, or alpha-lipoic acid [25mg and 50mg/kg] in association with kainic acid[4 micro g]. We performed behavior monitoring[spontaneous seizure, learning and memory by Y-maze and passive avoidance test], intracranial electroencepholography [iEEG] recording, histological analysis, to evaluate the anti- epilepsy effect of alpha-lipoic acid in kainate-induced epileptic rats. Behavior data showed that the kainate rats exhibit spontaneous seizures, lower spontaneous alternation score inY-maze tasks [p<0.01], impaired retention and recall capability in the passive avoidance test [p<0.05]. Administration of alpha-lipoic acid, in both doses, significantly decrease the number of spontaneous seizures, improved alternation score in Y-maze task [p<0.005] and impaired retention and recall capability in the passive avoidance test [p<0.01] in kainite rats. Moreover, lipoic acid could improve the lipid peroxidation and nitrite level and superoxid dismutase activity. This study indicates that lipoic acid pretreatment attenuates kainic acid-induced impairment of short-term spatial memory in rats probably due to its antioxidant activity

Antiepileptic and antioxidant effect of brassica nigra on pentylenetetrazol-induced kindling in mice

Considering the high rate of epilepsy today, with respect to the insufficiency of the available therapies, new strategies and methods are recommended for medical treatment of epileptic patients. Therefore, the present study experimentally investigated the anticonvulsant effect of a herbal medicine candidate brassica nigra, by using kindling method. Sixty male mice were randomly selected and divided into six experimental groups [n = 10] including: 1-control, 2-pentylentetrazole [PTZ]-kindled mice, 3-positive control group received valproate [100 mg/Kg] as anti-convulsant drug, 4-5 and 6 received brassica nigra seed extract in three doses [75, 150 and 300 mg/Kg; IP]. All groups except for the control ones were kindled by 11 period injections of PTZ [35 mg/Kg; IP]. In the 12th injection, all groups except for the control group were tested for PTZ challenge dose [75 mg/Kg]. However, the exhibited phases of seizure [0-6] were observed and noted till 30 min after the PTZ injection. At last, the brains of all the mice were removed and then malondialdehyde [MDA], superoxide dismutase [SOD] and nitric oxide [NO] levels of the brain tissues were determined. Statistical analysis of the data shows that the seed extract could reduce the intensity, improvement and duration of seizure. In addition, the brassica nigra extract increased the SOD and NO levels and decreased the MDA level in the brain tissues. Attained results show that the extract of Brassica nigra seed can be used in grand mal seizure treatment. Moreover, the antiepileptic effect of this extract is probably caused by its antioxidant properties and acts via enzyme activity mechanism

Chronic oral epigallocatechin-gallate alleviates streptozotocin-induced diabetic neuropathic hyperalgesia in rat: involvement of oxidative stress

Due to the anti-diabetic and antioxidant activity of green tea epigallocatechin-gallate [EGCG], this research study was conducted to evaluate, for the first time, the efficacy of chronic treatment of EGCG on alleviation of hyperalgesia in streptozotocin-diabetic [STZ-diabetic] rats. Male Wistar rats were divided into control, diabetic, EGCG-treated-control and diabetic and sodium salicylate [SS]-treated control and diabetic groups. For induction of diabetes, STZ was intraperitoneally injected [IP] at a single dose of 60 mg/Kg. EGCG was orally administered daily at doses of 20 and 40 mg/Kg for seven weeks; one week after diabetes induction. Finally, hyperalgesia was assessed using standard formalin, hot tail immersion and paw pressure tests. Meanwhile, markers of oxidative stress in brain were measured. Diabetic rats showed a marked chemical, thermal and paw pressure hyperalgesia, indicating that the development of diabetic neuropathy and EGCG treatment at a dose 40 mg/Kg significantly ameliorated the alteration in hyperalgesia [p < 0.05] in diabetic rats as compared with untreated diabetics. EGCG treatment [40 mg/Kg] also significantly decreased diabetes-induced thiobarbituric acid reactive substances formation [p < 0.05] and nitrite [p < 0.05] content and reversed the reduction of antioxidant defensive enzyme superoxide dismutase [p < 0.05]. The results may suggest therapeutic potential of EGCG for the treatment of diabetic hyperalgesia through the attenuation of oxidative stress

[ effect of curcumin on serum level of aspartate and alanine amoinotransferase and cardiac level of oxidative stress markers in diabetic rats]

Diabetes mellitus in long term accompanies with enhanced oxidative stress and decreased activity of antioxidant defense system. Due to antidiabetic and antioxidant activity of effective constituent of turmeric, curcumin, the effect of this component on serum level of aspartate and alanine aminotransferase and cardiac level of some oxidative stress markers were determined. In this experimental study, rats were divided into 5 groups, i.e. control, curcumin-treated control [50 mg/kg], diabetic, and curcumin-treated diabetic groups [10 and 50 mg/kg]. Curcumin was administered 7 days after streptozotocin injection for 5 weeks. Serum level of aspartate and alanine aminotransferase and heart tissue level of malondialdehyde [MDA] and nitrite and activity of Superoxide dismutase [SOD] were measured. Diabetic rats showed a significant increase in serum level of aspartate and alanine aminotransferase [p<0.01-0.05], while high-dose curcumin significantly reduced serum level of these enzymes [p<0.05]. In addition, diabetes was followed by increased level of MDA and nitrite in heart tissue [p<0.05-0.01] and non-significant decrease of SOD activity, whlie high-dose curcumin treatment significantly reduced MDA and nitrite level [p<0.05] and did not significantly change activity of SOD. Chronic treatment with curcumin could improve serum level of alanine and aspartate aminotransferase and some oxidative stress markers in cardiac tissue of diabetic rats

[ effect of thymoquinone on short-term spatial memory, passive avoidance learning and memory of diabetic rats and the involvement of hippocampal oxidative stress]

Chronic diabetes mellitus accompanies disturbance in learning, memory, and cognitive skills. With regard to anti-diabetic and antioxidant activity of thymoquinone [TQ], the effect of its chronic administration on learning and memory of diabetic rats was investigated. In this experimental study, male rats were divided into control, high dose TQ-treated control, diabetic, and low and high dose TQ- treated diabetic groups. TQ was administered i.p. at doses of 2.5 and 5 mg/kg one week after diabetes induction by streptozotocin, for 5 weeks. For evaluation of learning and memory, initial [IL] and step-through latencies [STL] were determined at the end of the study using passive avoidance test, and alternation behavior percentage was obtained using Y maze. In addition, hippocampal homogenate malondialdehyde [MDA] level was measured. STL significantly decreased in diabetic [p<0.01] and TQ-treated diabetic groups [p<0.001]; TQ treatment did not improve it in any of its doses. Alternation percentage was significantly lower in the diabetic group compared to the control [p<0.005]. TQ-treated diabetic group [at a dose of 5 mg/kg] showed a significantly higher score compared with diabetic group [p<0.01]. Diabetic rats also showed a significant increase in tissue level of malondialdehyde [p<0.01] and TQ treatment significantly reduced the level of MDA [p<0.05]. Although chronic treatment of diabetic rats with TQ could not enhance the capability of consolidation and recall in diabetic rats, it could improve spatial memory in them; part of its effect is via attenuation of lipid peroxidation

effect of the flavonoid quercetin on pain sensation in diabetic rats

Introduction: Hyperalgesia is considered as one of the marked signs of subchronic diabetes mellitus in patients that could affect their lifestyle. This study was designed to investigate the anti-nociceptive effect of chronic administration of quercetin in streptozotocin [STZ]-diabetic rats using formalin and hot tail immersion tests. Methods: Rats were divided into control, control or diabetic groups receiving sodium salicylate, untreated diabetic, and quercetin-treated control and diabetic groups. The treatment groups received i.p. administration of quercetin at a dose of 10 mg/kg for 6 weeks. Finally, hyperalgesia were assessed using standard formalin and hot tail immersion tests. Meanwhile, some markers of oxidative stress were also measured in brain tissue. Results: Quercetin or SS treatment of diabetic rats significantly reduced pain score in chronic phase of formalin test [p<0.05]. Regarding hot tail immersion test, diabetic rats showed a significant reduction in tail flick latency as compared to control ones [p<0.05] and quercetin treatment of diabetic rats did significantly increase this latency relative to untreated diabetics [p<0.05]. Quercetin treatment of diabetic rats also significantly decreased brain level of malondialdehyde [MDA] [p<0.05] and nitrite [p<0.05] and slightly increased activity of superoxide dismutase [SOD] relative to diabetics. Discussion: Taken together, chronic administration of quercetin could attenuate nociceptive score in chronic phase of formalin test in streptozotocin-diabetic rats and could also increase threshold of thermal nociception

Varenicline ameliorates learning and memory deficits in amyloid beta[25-35] rat model of Alzheimer's Disease

Alzheimer's disease [AD] is a enfeeble neurodegenerative disorder characterized by increased beta-amyloid [Abeta] deposition and neuronal dysfunction leading to impaired learning and recall. Among proposed risk factors, impaired cholinergic transmission is a main cause for incidence of disease. In the present study, effects of the intracerebroventricularly administration of an agonist of nicotinic cholinergic receptors, varenicline[0.5 and 2 microg/microl], on learning and memory impairments induced by intrahippocampal Abeta[25-35] injection was assessed in rats. The results showed that the intrahippocampal Abeta[25-35] injected rats exhibit lower spontaneous alternation score inY-maze tasks [p<0.05], impaired retention and recall capability in the passive avoidance test [p<0.05], and fewer correct choices [p<0.001] and more errors[p<0.001] in the RAM task. Varenicline, almost in both doses, significantly improved alternation score in Y-maze task [p<0.001], impaired retention and recall capability in the passive avoidance test [p<0.05], and correct choices in the RAM task [p<0.001]. This study indicates that varenicline pretreatment attenuates Abeta- induced impairment of short-term spatial memory in rats probably due to its agonist activity at nicotinic receptors.

flavonoid hesperetin alleviates behavioral abnormality in 6-hydroxydopamine rat model of hemi-parkinsonism

Parkinson's disease [PD] is a neuropathologieal and debilitating disorder involving the degeneration of mesencephalic dopaminergieneurons. Neuroproteetive effect of hesperetin has already been reported, therefore, this study examined whether the administration of this flavonoid would attenuate behavioral abnormalities in an experimental model of PD in rat. For this purpose, unilateral intrastriatal 6-hydroxydopamine [6-OHDA, 12.5 microg/5micro1 of saline-ascorbate]-lesioned rats were pretreated i.p. with hesperetin [10 mg/ kg]. It was found out that hesperetin administration attenuates the rotational behavior in lesioned rats. In summary, hesperetin administration attenuates behavioral abnormality in hemiparkinsonian rats and this may be of benefit, along with other therapies, in neurodegenerative disorders including PD

[Antinociceptive effect of chronic administration of the flavonoid hesperetin in diabetic rats: behavioral evidence]

This study was designed to investigate the antinociceptive effect of chronic administration of the flavonoid hesperetin in streptozotocin-diabetic rats using formalin and hot tail immersion tests. Rats were divided into 5 control groups, hesperetin-treated control, diabetic, sodium salicylate [SS] -treated diabetic, and hesperetin-and glibenclamide-treated diabetic groups. Hesperetin [10 mg/kg] was administered i. p. one other day 1 week after diabetes induction for 6 weeks. Finally, thermal pain tolerance and nociception were evaluated using hot water tail immersion and formalin tests respectively. Diabetic rats exhibited a higher score of pain at both phases of the formalin test [P<0.05] and hesperetin-treated diabetic rats exhibited a lower nociceptive score at both phases of the test [P<0.05]. Regarding thermal pain tolerance, diabetes significantly reduced tail immersion latency [P<0.01] and hesperetin treatment did produce a significant change in this respect [P<0.05]. Chronic treatment with hesperetin for 6 weeks does mildly increase thermal pain tolerance and reduces chemical nociception in an experimental model of diabetes mellitus and this may be considered as an auxiliary treatment for diabetic hyperalgesia

Effect of oral feeding of Allium ascalonicum L. on thoracic aorta contractile response in diabetic rats

Diabetes mellitus is accompanied with higher incidence of cardiovascular disorders. There is some evidence on antidiabetic potential of Allium ascalonicum L. [AA]. Therefore, this study was conducted to evaluate the beneficial effect of oral two-month administration of AA on contractile reactivity of isolated thoracic aorta from diabetic rats. Male Wistar rats were divided into control, AA-treated control, diabetic, and AA-treated diabetic groups. For induction of diabetes, streptozotcin [STZ] was intraperitoneally administered [60 mg/Kg]. Meanwhile, treated groups received AA mixed with standard pelleted food at a weight ratio of 6.25% for 2 months. Serum glucose level was measured in weeks 4 and 8. Also after 2 months contractile reactivity of thoracic aortic rings to KC1 and noradrenaline was determined using isolated tissue setup. Serum glucose level showed a significant increase in diabetic animals [p<0.001] and this was significantly attenuated in AA-treated diabetic group [p<0.005]. In addition, AA-treated diabetic group showed a lower contraction to KC1 and noreadrenaline [p<0.05] as compared to diabetic group. Meanwhile, there was no significant difference between control and AA-treated control groups regarding contractile reactivity. Oral administration of AA for 2 months could improve hyperglycemia and also attenuate the contractile responsiveness of the vascular system and this may prevent the development of hypertension in diabetic rats

effect of crataegus spp branchlet feeding on endothelium-dependent contractile and relaxatory response of thoracic aorta from diabetic rats

Diabetes mellitus is accompanied with higher incidence of cardiovascular disorders. There is some evidence on antidiabetic and cardiovascular improving potential of Crataegus spp [CS]. Thus, the endothelium-dependent effect of oral administration of CS branchlet for 6 weeks on contractile and relaxatory response of thoracic aorta from diabetic rats was investigated. Male Wistar rats were divided into control, CS-treated control, diabetic, CS-treated diabetic, and glibenclamide-treated diabetic groups. Treated groups received CS-mixed pelleted food at a weight ratio of 6.25%. Body weight and serum glucose level was measured before the study and at weeks 3 and 6. At the end of study, contractile reactivity of thoracic aortic rings to KC1 and phenylephrine and relaxatory response to acetylcholine and sodium nitroprusside was determined using isolated tissue setup. Serum glucose level significantly decreased in CS-treated diabetic group [p<0.01] versus untreated diabetics. In addition, endothelium-intact CS-treated diabetic group showed a significantly lower contraction to KC1 and phenylephrine [p<0.05] as compared to diabetic group and endothelium removal abolished this response. Meanwhile, relaxation response of endothelium-intact rings to acetylcholine was significantly higher in CS-treated diabetic group as compared to diabetics [p<0.05]. In addition, there were no significant changes amongst the groups regarding relaxatory response to sodium nitroprusside. Chronic oral administration of CS through affecting endothelial-related agents could decrease contractile response and enhance relaxatory response in aortic tissue of diabetic rat and this may be beneficial in prevention of long-term vascular complications of diabetes

[Endothelium-dependent and- independent effects of vaccinium myrtillus feeding on contractile reactivity of thoracic aorta from diabetic rats]

Diabetes mellitus is followed by higher incidence of cardiovascular disorders. There is some evidence on protective and antidiabetic effects of Vaccinium myrtillus [VM]. Thus, the endothelium-dependent and -independent effect of oral administration of VM for 6 weeks on contractile and relaxatory response of thoracic aorta from diabetic rats was investigated. Male rats were divided into control, VM-treated control, diabetic and VM-treated diabetic groups. Treated groups received VM-mixed pelleted food at a weight ratio of 5%. Body weight and serum glucose levels were measured before the study and at weeks 3 and 6. At the end of study, contractile reactivity of thoracic aortic rings to KCl and phenylephrine and relaxatory response to acetylcholine [with endothelium] and sodium nitroprusside [without endothelium] was determined using isolated tissue setup. Serum glucose levels significantly decreased in VM-treated diabetic group versus untreated diabetics [P=0.04]. In addition, endothelium-intact VM-treated diabetic group showed a significantly lower contraction to KCl and phenylephrine [p=0.04] as compared to diabetic group and endothelium removal reduced this difference. Meanwhile, relaxation response of endothelium-intact rings to acetylcholine was significantly higher in VM-treated diabetic group as compared to diabetics [p=0.02]. Chronic oral administration of VM through affecting synthesis and release of endothelial vasoactive agents and also via direct effects on vascular smooth muscle could decrease contractile and enhance relaxatory responses in aortic tissue of diabetic rat. These effects may have the beneficial effects in prevention of some long-term vascular complications of diabetes

beneficial effect of [-]-epigallocatechin-3-gallate in an experimental model of Alzheimer's disease in rat: a behavioral analysis

Progressive cognitive decline is one of the hallmark symptoms of Alzheimer's disease [AD] which can be modeled by beta-amyloid injection into specific regions of brain. Since epigallocatechin-3-gallate [EGCG] is a potent antioxidant agent which its role against oxidative stress and inflammation has been shown in prior studies, we tried to determine whether EGCG administration protects against beta-amyloid-induced memory and coordination impairment in rats. Animals [male Wistar rats] were divided into four groups: sham operated, EGCG-pretreated sham operated [sham + EGCG], untreated lesion [lesion], and EGCG-pretreated lesion [lesion + EGCG]. Animals in lesion, lesion + EGCG, and sham + EGCG groups received sterile saline or saline plus EGCG [10 mg/kg] intraperitoneally one day pre-surgery and every other day for three weeks. The lesion was induced one day after EGCG pretreatment by injection of 4 microl of sterile saline or water containing 2 nmol/microl beta-amyloid [1-40] into the hippocampal fissure. For behavioral analysis, psychomotor coordination [PMC] index and spontaneous alternation behavior were assessed using Rota-rod Treadmill and Y-maze, respectively at the third week post-lesion. We found that beta-amyloid [1-40] injection into hippocampus can decrease these behavioral indexes in lesion group in comparison with sham group which is similar to behavioral changes in AD. On the other hand, pretreatment with EGCG can improve the PMC index and spatial Y-maze alternation in the lesion + EGCG group in comparison with lesion group. We concluded that EGCG can be effective in restoring beta-amyloid-induced behavioral derangements in rats regarding coordination and memory abilities