Activation of sphingosine 1-phosphate receptor-1 by SEW2871 improves cognitive function in Alzheimer's disease model rats

Sphingosine-1 phosphate (S1P) is involved in a variety of cellular processes via activation of S1P receptors (S1PRs; S1PR1 to S1PR5) that are highly expressed in the brain. It has been shown that the level of S1P is reduced in the brain of Alzheimer's disease (AD) patients. However, there is no study designed to evaluate the expression of S1PRs in AD brains. The objectives of the present work are (1) to examine the expression of S1PR1-3 in the hippocampus of beta amyloid (Aβ) 1-42 injected rats and (2) to clarify the effects of chronic S1PR1 activation on S1PR1-3 levels, spatial memory deficit and hippocampal damage in AD rats. SEW2871, the S1PR1 selective agonist, repeatedly was injected intraperitoneally during a period of two weeks. Upon Western Blot data bilateral intrahippocampal injection of Aβ1-42 decreased the expression of S1PR1 while increased S1PR2 level and did not affect that of S1PR3. We found that chronic administration of SEW2871 inhibited the reduction of S1PR1 expression and ameliorated spatial memory impairment in the Morris water maze task in rats. In addition, SEW 2871 attenuated the Aβ1-42-induced hippocampal neuronal loss according to Nissl staining findings. Data in the current study high lights the importance of S1PR1 signaling pathway deregulation in AD development and suggests that activation of S1PR1 may represent a potential approach for developing new therapeutics to manage memory deficit and apoptosis associated with neurodegenerative disorders such as AD

Effect of Myrtus Communis Hydro-Alcoholic Extract on Chronic Restraint Stress-Induced Spatial Memory Deficit in Adult Male Rats

Background and Aim: Chronic restraint stress impairs spatial learning and memory. Myrtle (Myrtus communis) has antioxidant, antidiabetic, hepatoprotective and neuroprotective properties. The aim of this study was to investigate the effect of myrtle hydroalcoholic extract on chronic restraint stress-induced spatial learning and memory deficit in adult male Wistar rats. Materials and Methods: In this experimental study, 80 adult male Wistar rats were allocated to eight groups (10 in each) included control group (intact), myrtle0.75, myrtle1.5, myrtle3 groups (were gavaged with hydroalcoholic extract of myrtle at 0.75, 1.5 and 3 mg/ kg bw doses), stress group (restrained in restrainers for 6 hours per day for 21 consecutive days), stress- myrtle0.75, stress-myrtle1.5 and stress- myrtle3 groups (received myrtle extract at 0.75, 1.5 and 3 mg/ kg bw doses and exposed to chronic immobility stress). Spatial learning and memory were examined through the Morris water maze test. Findings: Chronic immobilization stress caused spatial learning and memory impairment. Consuming doses 1.5 and 3 of Myrtle extract to stressed animals caused significant decrease in spent time and swam distance to reach the hidden platform (p<0.05) and increased time lapsed in target quadrant comparing with stress group (p<0.05). Conclusion: It has been concluded that myrtle extract can improve spatial learning and memory in rats exposed to stress in a dose dependent manner

Dried lemon peel extract improves memory and reduces anxiety-like behavior in rats exposed to chronic immobilization

Background and Aims: Chronic immobilization is a type of stress that causes behavioral disorders such as anxiety and memory deficits by inducing oxidative stress and inflammation and changing the level of neurotransmitters in the brain. In this research, we investigated the effect of the hydroalcoholic extract of dried lemon peel (Citrus aurantifolia) on learning, spatial memory, and anxiety-like behavior in adult male rats exposed to chronic immobilization. Materials and Method: To induce immobilization stress, the rats were placed in the restrainer for 6 hours every day for 21 consecutive days. Lemon extract (400 mg/kg) was also treated by gavage to the animals. Spatial learning and memory were assessed using the Morris blue maze, and anxiety was studied using an elevated plus maze. Results: The lemon extract treatment made the animals exposed to immobilization stress swim more time and distance in the target quarter in the water maze compared with the stress group (P < 0.05). The extract increased the percentage of entry into the open arm (P < 0.01) and the percentage of time spent in the open arm (P < 0.05) of the elevated plus maze in these animals. Conclusion: Dried lemon peel extract improved learning and spatial memory in animals exposed to chronic immobilization and reduced anxiety-like behavior in them. Dried lemon peel extract probably has a neuroprotective effect

Anxiolytic and antidepressant effects of tarragon (Artemisia dracunculus L.) hydro-alcoholic extract in male rats exposed to chronic restraint stress

Tarragon (Artemisia dracunculus L.) has antioxidant, anti-diabetic, anti-bacterial and anti-inflammatory proper-ties. The aim of this study was to evaluate the effect of tarragon hydro-alcoholic extract on anxiety and depression in male rats exposed to chronic restraint stress. Forty eight male rats were randomly divided into six groups including 1) control, 2) stress, 3) tarragon 100, 4) tarragon 500, 5) stress-tarragon 100 and 6) stress-tarragon 500. Groups 2, 5, and 6 were placed in restrainer for 21 consecutive days, 6 hours a day. Groups 3, 4, 5, and 6 were gavaged with tarragon extract of different do-ses (100 and 500mg/kg). At the end of this 21-day period, anxiety and depression were evaluated by elevated plus maze and forced swimming test. Data analysis was performed using one-way ANOVA, p<0.05 being considered significant. The pe-rcentages of open arm entry and time spent in open arm increased significantly in tarragon-stress groups compared with st-ress group (p<0.05). Tarragon extract decreased significantly the immobility time in rats exposed to stress in forced swim-ming test (p<0.01). The results suggested that hydro-alcoholic extract of Artemisia dracunculus L. reduced the anxiety and depression in rats exposed to chronic immobilization stress, probably due to its anti-oxidant compound

Anxiolytic and antidepressant effects of Basil (Ocimum basilicum L.) hydro-alcoholic extract in male rats exposed to chronic restraint stress

Introduction: Studies show that chronic stress can lead to anxiety and depression. Basil (Ocimum basilicum&nbsp;L.) has antioxidant, anti-inflammatory, anti-apoptotic, anti-diabetic and anti-nociceptive properties. The aim of this study was to investigate the effect of basil hydro-alcoholic extract on chronic restraint stress-induced anxiety and depression in male Wistar rats. Methods: In this experimental study, 48 rats were allocated to 6 groups including: Control, Basil200 and Basil400 (receiving doses 200, 400 mg/kg/bw of Basil extract during 21 days), Stress (restrained in restrainers for 6hours per day for 21 consecutive days), Stress-Basil200 and Stress-Basil400 (received Basil extract in addition to chronic immobility stress). At the end of this period, anxiety and depression were evaluated using elevated plus maze (EPM) and forced swimming test, respectively. Results: Results show that chronic immobility causes anxiety and depression like behaviors in rats. Taking both doses of the Basil extract led to significant increase in percentages of open arm entry and time spent in open arm in EPM test compared with Stress Group (P<0.05). The results of forced swimming test showed significant increase in latency time (p<0.05) and decrease in immobility time (p<0.05) in Stress-Basil groups compared with Stress group. Conclusion: It is concluded that the Basil hydro-alcoholic extract, reduced anxiety and depression like behaviors in rats exposed to chronic restraint stress

Effect of Royal Jelly on Blood Glucose and Lipids in Streptozotocin Induced Type 1 Diabetic Rats

Abstract Background: Diabetes is the most common endocrine disorder that leads to hyperglycemia and hyperlipidemia. Royal jelly is as a bee-collected natural product has diverse biological properties and that is rich in natural antioxidants. The aim of this study was to investigate the effects of royal jelly on serum glucose and lipids profile in streptozotocin induced type 1 diabetic rats. Materials and Methods: In this experimental study, 40male Wistar rats were divided into 5 groups(8 in each): control, diabetic rats, Glibenclamide, and two groups of royal jelly- treated diabetic. Diabetes was induced in the rats by injection of streptozotocin (60 mg/kg b.w) intraperitoneally. The royal jelly was gavaged at doses of 100 and 200 mg/kg after streptozotocin injection for30 days. At the end of this period, levels of glucose, cholesterol, triglyceride, LDL and HDL in serum were measured. Results: Royal jelly and Glibenclamide significantly decreased the levels of glucose, cholesterol, triglyceride and LDL in diabetic rats (p<0.01). In addition, significant increase (p<0.01) in HDL level was observed in royal jelly-treating rats in comparison to the diabetic rats. Conclusion: The results indicated that royal jelly may be used effectively in controlling and attenuating the complications of diabetes. The hypoglycemic and hypolipidemic effects of royal jelly may be due to the presence of antioxidants

Effect of Menthol on SFRP1 Expression Level and HIF-1α/VEGF Signaling in Diethylnitrosamine-induced Kidney Damage in Male Mice

Background: Many scientific Researches have shown that diethylnitrosamine, which is used to induce liver carcinoma, has destructive effects on the kidney. Menthol is a monoterpene type with antioxidant, anti-inflammatory, and anti-cancer effects. In the current study, we investigated the effect of menthol on the expression of tumor-related factors and HIF-1α/VEGF signaling in the kidney cells of mice receiving diethylnitrosamine. Methods: In this research, 16 male mice at the age of 14 days were divided into four groups including Control, Menthol, Nitrosamine, and Nitrosamine-Menthol groups. Nitrosamine and Nitrosamine-Menthol groups received diethyl-nitrosamine intraperitoneally (25 mg/kg) at the age of 14 days. Menthol and Nitrosamine-Menthol groups also received menthol by gavage (50 mg/kg) three times a week for 6 consecutive months. At the end of this period, the expression level of SFRP1, VHL, CTNNB1, HIF-1α, and VEGF in the kidney cells was measured using real-time PCR method. Results: Menthol treatment caused a significant increase in the expression level of SFRP1 (P=0.021) and VHL (P=0.013) and a significant decrease in the expression level of CTNNB1 (P=0.001), HIF-1α (P=0.000) and VEGF (P=0.000) in the kidney cells of Nitrosamine-Menthol treated group compared to the Nitrosamine group. Conclusion: The results of this study showed that menthol prevents the decrease in the expression of tumor suppressor factors and the increase in the expression of tumor stimulating factors and factors effective in angiogenesis in the kidney of mice treated with diethyl-nitrosamine, so menthol is probably useful in prevention and treatment of renal cancer