Evaluation of nicotinic receptor of pedunculopontine tegmental nucleus in central cardiovascular regulation in anesthetized rat

Objective(s): Cholinergic neurons are important neurons in the Pedunculopontine tegmental nucleus (PPT). In this study, nicotinic receptor of the PPT in central cardiovascular regulation in the anesthetized rat was evaluated. Materials and Methods: Saline, acetylcholine (Ach; doses: 90 and 150 nmol), hexamethonium (Hexa; doses: 100 and 300 nmol) and higher doses of Hexa (300 nmol) + Ach (150 nmol) microinjected into the PPT. The femoral artery was cannulated and cardiovascular responses were continuously recorded by a power lab system. After injection of drugs, peak changes of mean arterial pressure (∆MAP), systolic blood pressure (∆SBP) and heart rate (∆HR) calculated and compared with saline group.Results: The ∆SBP and ∆MAP significantly decreased by two doses of Ach (PConclusion: These results indicate that nicotinic receptor of the PPT has an inhibitory effect on ∆HR with no significant effect on ∆MAP or ∆SBP

Effects of Zataria multiflora Extract and Carvacrol on Doxorubicin-Induced Oxidative Stress in Rat Brain

Background: Due to the antioxidant effects of Zataria multiflora (ZM) and Carvacrol (CAR) in various problems and the prominent role of the ROS in neurotoxicity induced by Doxorubicin (DOX), this study was designed to investigate the effects of ZM hydroalcoholic extract and CAR on DOX-induced oxidative stress in rat brain. Methods: 24 male rats were randomly divided into four groups including: 1)Control ,2)Doxorubicin (DOX) that received DOX via a tail vein on the first day of the study, 3,4) ZM+DOX and CAR+DOX which received ZM and CAR by gavage for 28 consecutive days. Brain tissue removed for redox markers evaluation. Results: MDA level in the DOX group was significantly increased compared to control group while in treated groups did not show any significant changes in comparison with the DOX group. Also, Thiol content in DOX group showed significant reduction compared to control group. Thiol contents in treated groups showed no significant difference compared to DOX group. Catalase (CAT) activity, an antioxidant enzyme, in the DOX group were significantly decreased compared to control group and increased in treated rats in comparison with the DOX group. Activity of Superoxide dismutase (SOD), an antioxidant enzyme, in the DOX group was significantly reduced compared to control group and increased in treated rats in comparison with the DOX group. Conclusion: The present study showed that ZM hydroalcoholic extract and CAR could inhibit DOX induced oxidative stress of the brain mainly with effect on the enzymatic antioxidant defense system

Effect of the cholinergic system of the lateral periaqueductal gray (lPAG) on blood pressure and heart rate in normal and hydralazine hypotensive rats

Objective(s): Due to the presence of the cholinergic system in the lateral periaqueductal gray (lPAG) column, the cardiovascular effects of Acetylcholine (ACH) and its receptors in normotensive and hydralazine (HYD) hypotensive rats in this area were evaluated.Materials and Methods: After anesthesia, the femoral artery was cannulated and systolic blood pressure (SBP), mean arterial pressure (MAP), heart rate (HR), and also electrocardiogram for evaluation of low frequency (LF) and high frequency (HF) bands, important components of heart rate variability (HRV), were recorded. ACH, atropine (Atr, a muscarinic antagonist), and hexamethonium (Hex, an antagonist nicotinic) alone and together microinjected into lPAG, changes (Δ) of cardiovascular responses and normalized (n) LF, HF, and LF/HF ratio were analyzed.Results: In normotensive rats, ACH decreased SBP and MAP, and enhanced HR while Atr and Hex did had no effects. In co-injection of Atr and Hex with ACH, only ACH+Atr significantly attenuated parameters. In HYD hypotension, ACH had no affect but Atr and Hex significantly improved the hypotensive effect. Co-injection of Atr and Hex with ACH decreased the hypotensive effect but the effect of Atr+ACH was higher. In normotensive rats, ACH decreased nLF, nHF, and nLF/nHF ratio. These parameters in the Atr +ACH group were significantly higher than in ACH group. In HYD hypotension nLF and nLF/nHF ratio increased which was attenuated by ACH. Also, Atr+ACH decreased nLF and nLF/nHF ratio and increased nHF.Conclusion: The cholinergic system of lPAG mainly via muscarinic receptors has an inhibitory effect on the cardiovascular system. Based on HRV assessment, peripheral cardiovascular effects are mostly mediated by the parasympathetic system

Crocin prevents acute angiotensin II-induced hypertension in anesthetized rats

Objective: Angiotensin II (Ang II), the main product of renin-angiotensin system (RAS) has a well-known role in cardiovascular regulation. Over-production of Ang II is one of the important underlying mechanisms of hypertension. In this study, the effect of crocin on cardiovascular responses in rats with acute hypertension induced by Ang II was evaluated. Materials and methods: Rats were divided into six groups (n = 6): 1) Control: rats that received saline, 2) Ang II: rats that received Ang II (300 ng/kg) infused in two min, 3) Losartan (Los) + Ang II : rats that received Los (10 mg/kg, i.v) before Ang II, and 4-6) Crocin (Cro) + Ang II groups: rats that received three doses of crocin (50, 100 and 200 mg/kg, slow i.v) 10 min before Ang II. Femoral artery and vein were cannulated for recording of cardiovascular parameters and injection of drugs, respectively. Systolic blood pressure (SBP), mean arterial blood pressure (MAP) and heart rate (HR) were continuously recorded by power lab system. After injection of reagents and extracts, maximum changes (∆) of MAP, SBP and HR were recorded and compared with control group. Results: Ang II (300 ng/kg) increased maximal changes in MAP, SBP and HR compared to control group (

Cardiovascular effects of nitrergic system of the pedunculopon-tine tegmental nucleus in anesthetized rats

Objective(s): Nitric oxide (NO) is an important neurotransmitter in central nervous system involved in central cardiovascular regulation. The presence of NO in the pedunculopontine tegmental (PPT) nucleus has been shown, but its cardiovascular effect has not been determined. In the present study, the cardiovascular effect of NO in the PPT nucleus was evaluated. Materials and Methods: After induction of anesthesia, a polyethylene catheter (PE-50) filled with heparinized saline inserted into the femoral artery, and the blood pressure (BP) and heart rate (HR) were continuously recorded. Animals were then placed in a stereotaxic apparatus and maximum changes of mean arterial pressure (∆MAP) and heart rate (∆HR) after microinjection of two doses of NG-nitro-L-arginine methyl ester (L-NAME, 30 and 90 nmol), L-arginine (L-Arg 10 and 50 nmol) and sodium nitroprusside (SNP, 9 and 27 nmol) into the PPT were provided and compared with control group (One-way ANOVA). Results: Both doses of L-NAME significantly increased ∆MAP compared to control (P

Effect of total hydroalcholic extract of Nigella sativa and its n-hexane and ethyl acetate fractions on ACHN and GP-293 cell lines

AbstractMedicinal plants are noted for their many advantages including the ability to treat diseases such as cancer. In this study, we examined the antitumor effect of the medicinal plant Nigella sativa on the morphology, survival, and apoptosis of ACHN (human renal adenocarcinoma) and GP-293 (normal renal epithelial) cell lines. From a hydroalcoholic extract of N. sativa, n-hexane and ethyl acetate fractions were extracted. Cells were treated with various concentrations of total hydroalcholic extract and n-hexane and ethyl acetate fractions; cell viability, morphological changes, and apoptosis were then determined. Results were presented as mean ± standard error of the mean (SEM). One-way analysis of variance (ANOVA) was applied for the statistical analysis of the data. The total extract and the fractions in a dose- and time-dependent manner reduced the cell viability in ACHN with no effect on the GP-293 cell line. In addition, the total extract resulted in more morphological changes in the ACHN cells compared to the GP-293 cells. The effect of the total extract in inducing apoptosis after 48 hours in the ACHN cell line was greater than in GP-293. In addition, the effect of the two fractions was lower than the total extract at all used concentrations. Therefore, the effect of total extract and n-hexane and ethyl acetate fractions of N. sativa on cell viability and apoptosis in the ACHN cell line is greater than in the GP-293 cell line. However, the effect of the total extract is higher than either of the two fractions on their own

Protective effects of long-term administration of Ziziphus jujuba fruit extract on cardiovascular responses in L-NAME hypertensive rats

Objective: Ziziphus jujuba stimulates the release of nitric oxide (NO).  Because NO is involved in cardiovascular regulations, in this study the effects of hydroalcoholic extract of Z. jujuba on cardiovascular responses in acute NG-nitro-L-arginine methyl ester (L-NAME) hypertensive rats were evaluated. Materials and Methods: Rats were divided into 6 group (n=6): 1) saline, 2) L-NAME received (10mg/kg) intravenously, 3) sodium nitroprusside (SNP) (50µg/kg)+L-NAME group received SNP before L-NAME and 4-6) three groups of Z. jujuba (100, 200 and 400mg/kg) that treated for four weeks and on the 28th day, L-NAME was injected. Femoral artery and vein were cannulated for recording cardiovascular responses and drug injection, respectively. Systolic blood pressure (SBP), Mean arterial pressure (MAP) and heart rate (HR) were recorded continuously. Maximal changes (∆) of SBP, MAP and HR were calculated and compared to control and L-NAME groups. Results: In L-NAME group, maximal ΔSBP (L-NAME: 44.15±4.0 mmHg vs control: 0.71±2.1 mmHg) and ΔMAP (L-NAME: 40.8±4.0 mmHg vs control: 0.57±1.6 mmHg) significantly increased (p0.05). All doses of Z. jujuba attenuated maximal ∆SBP and ∆MAP induced by L-NAME but only the lowest dose (100 mg/kg) had significant effects (ΔSBP: 20.36±5.6 mmHg vs L-NAME: 44.1±4.0 mmHg and ΔMAP: 20.8±4.5 mmHg vs L-NAME: 40.8±3.8 mmHg (p0.05). Conclusion: Because long-term consumption of Z. jujuba extract, especially its lowest dose, attenuated cardiovascular responses induced by L-NAME, we suggest that Z. jujuba has potential beneficial effects in prevention of hypertension induced by NO deficiency

Doxorubicin-induced renal inflammation in rats: Protective role of Plantago major

Objective: The aim of the present study was to evaluate the possible protective effect of Plantago major (P. major) extract against doxorubicin (DXR)-induced renal inflammation in rats. Materials and Methods: 80 male albino rats were randomly divided into 8 groups as follows: control, DXR, Ext (extract) 600, Ext1200, dexamethasone+DXR, vitamin E+DXR, Ext600+DXR, and Ext1200+DXR. Duration of the study was 35 days and DXR was intravenously injected on the 7th day of the experiment. Tumor necrosis factor-alpha (TNF-α) production and monocyte chemoattractant protein-1 (MCP-1) expression levels were assessed in the left kidney. Serum creatinine concentration and osmolarity were determined on the 1st, 14th, 21st, 28th and 35th days of the experiment. Results: DXR caused a significant increase in renal expression of MCP-1 and TNF-α production compared to control animals. Administration of dexamethasone, vitamin E and P. major extract significantly improved the expression of these inflammatory mediators compared to DXR group. Compared to day 1 in DXR group, serum osmolarity showed a significant increase on days 21, 28 and 35. Also, on these days, serum osmolarity in DXR group was significantly higher than that on the same days in control group. In Vit E+DXR and Ext 1200+DXR groups, there was no significant changes in serum osmolarity among different days of the study. However, in these groups, serum osmolarity on days 21, 28 and 35 showed a significant decrease compared to the same days in DXR group. Conclusion: Present results suggest that hydroethanolic extract of P. major protected renal tissue against DXR–induced renal inflammation