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Background: This study aimed to evaluate the effect of two weeks oral administration of pomegranate seed extract (PGSE) on active and passive avoidance memories after permanent bilateral common carotid arteries occlusion (2CCAO) to induce permanent cerebral ischemia in adult female rats. Methods: Seventy adult female Wistar rats (250 ± 20 g) were used. Animals were divided randomly into seven groups with 10 in each: 1) Sham-operated; 2) Ischemic; 3–6) Ischemic received PGSE (100, 200, 400 and 800 mg/2mL/kg, orally) for 14 days; 7) Ischemic received vehicle. In order to create 2CCAO, carotid arteries were ligatured and then cut bilaterally. Active and passive avoidance task were measured using criterion condition responses (CCRs) in Y-maze and step-through latency (STL) in two-way shuttle box in all female rats. Results: Both active and passive avoidance memories were significantly impaired in rats after cerebral hypoxia-ischemia (CHI) (P < 0.001). PGSE treatment significantly improved passive and active memory impairments with 2CCAO (P < 0.05, P < 0.01, and P < 0.001). No toxicity was observed even with high-dose PGSE consumption (800 mg/kg, for 14 days). Conclusion: PGSE exhibits therapeutic potential for avoidance memories, which is most likely related at least in part to its antioxidative and free radical scavenging actions.
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Background: Terminalia chebula Retz is traditionally used to relieve constipation. The current study was performed to investigate the pharmacological action of aqueous extract of Terminalia chebula seeds (ATC) in vitro and in vivo. Methods: Terminal pieces of rat ileum were suspended in organ bath containing Tyrode solution. The ileum spontaneous motility frequency and contractility were recorded isotonically. To induce ileal contraction, carbachol and ATC were added to the organ bath. In addition, the effect of hexamethonium, indomethacin, atropine, and verapamil on the ATC-induced ileal contractions was also investigated. The effectiveness of ATC on relieving morphine-induced constipation was investigated in an in vivo study by measuring the faecal number, faecal water content, and intestinal transit ratio. Results: ATC increased the frequency of ileum motility and tension of contraction dosedependently (P < 0.05). Responses induced by ATC were inhibited by pre-treatment of the tissue with verapamil. The ATC activities were not affected by atropine, hexamethonium, and indomethacin. The faecal number and faecal water content were increased dose-dependently by ATC (P < 0.05). Conclusion: The excitatory effects of ATC on ileal contractile frequency and tension are possibly mediated through Ca2+ channels activation. The results of the present study support the traditional usage of ATC for the treatment of constipation.
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Background: The antidiabetic and antilipaemic effects of Phoenix dactylifera leaf extract (PDE) and its fractions were investigated in various rat models. Methods: Diabetes was induced in male Wistar rats by alloxan monohydrate. Diabetic animals were randomly divided into 8 groups (1 diabetic control and 7 treated groups). Diabetic control animals received saline (5 mL/kg) orally, whereas the treatment groups received different doses of PDE (100, 200, and 400 mg/kg), PDE fractions (50, 100, and 200 mg/kg), or glibenclamide (4 mg/kg) orally once a day for 14 days. Blood was withdrawn for glucose determination on the 1st, 6th, 10th, and 14th days. The rats were fasted overnight and then sacrificed on the 14th day; blood was collected for biochemical evaluation, including the levels of blood glucose, plasma insulin, serum triglyceride, and cholesterol. Results: Subacute administration of PDE or its fractions in alloxan-induced diabetic rats significantly reduced blood glucose (P < 0.01). Water intake, serum triglyceride, and cholesterol also decreased in treated animals compared with the control group (P < 0.01). Plasma insulin level increased in the treated groups relative to the control group (P < 0.01). Conclusion: The results suggested that PDE exhibits antidiabetic and antilipaemic effects in alloxan-induced diabetic rats.
ABSTRACT
It is well established that the esophageal distention [ED] leads to gastric relaxation, partly by vago-vagal reflex, but till now, the effect of ED on gastric acid secretion has not been investigated. The aim of this study was to investigate the effect of ED on basal and stimulated gastric acid secretion. Adult male Wistar rats [200-240 g] were deprived of food but not the water 24 h before the experiments. Under urethane anesthesia [1.2 g/kg, i.p.], animals underwent tracheostomy and laparotomy. A catheter was inserted in the stomach through duodenum for gastric distention and gastric washout and the esophagus was cannulated with a distensible balloon orally to distend esophagus [0.3 ml, 10 min]. Gastric acid secretion was stimulated by gastric distention, carbachol [4 ?g/kg, i.p.] or histamine [5 mg/kg, s.c.]. Effects of vagotomy, NG-nitro-L-arginine methyl ester [L-NAME, 10 mg/kg, i.v.] and also hexamethonium were investigated. Basal and gastric distention- and carbachol, histamine-stimulated acid secretion were reduced by the ED [P<0.05, P<0.0001, P<0.01 and P<0.02, respectively]. L-NAME [10 mg/kg, i.v.] elevated the acid output [P<0.002]. Vagotomy reduced the inhibitory effect of the esophagus distention on gastric distention-induced acid secretion [P<0.01]. These results indicate that the vagus nerves are involved in the inhibitory effect of the ED on the basal and stimulated gastric acid secretion. Furthermore, nitric oxide could be involved
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Several reports have shown the various effects of grape [Vitis vinifera] seed extract such as antioxidant, hypotensive, hypolipidemic and vasodilatory effects. The aim of present study was to investigate the effect of grape leaf hydroalcoholic extract on isolated rat tracheal contractions induced by KCl and acetylcholine. The trachea was removed from male adult Sprague-Dawley rat and placed in an organ bath containing Krebs-Henseleit solution and contractions were recorded isometrically. The results demonstrate that the grape leaf extract at 0.5, 1, 2, 4 and 8 mg/ml significantly reduces the tracheal contractions induced by KCl [60 micro M] dose-dependently [P<0.0001]. Acetylcholine [55 micro M]-induced tracheal contractions were also attenuated at the same concentration of the extract [P<0.0001]. The grape leaf extract induced relaxation in the KCl-induced contraction in trachea was unaffected neither by nitric oxide [NO] synthase inhibitor [L-NAME, 100 microM] nor by beta-adrenoceptor antagonist [propranolol 1 microM]. Our results suggest that the bronchodilatory effect of grape leaf extract is mediated via the voltage dependent calcium channels. Furthermore, the beta-adrenergic and NO are not involved
Subject(s)
Animals, Laboratory , Plant Leaves , Plant Extracts/pharmacology , Plant Extracts , Rats, Sprague-Dawley , Bronchodilator AgentsABSTRACT
Zataria multiflora Boiss. is used in Iranian traditional medicine to treat gastrointestinal disorders and menrrhalgia. The inhibitory effect of this herb on rat ileum contractions is also reported. The aim of this study was to investigate the effect of Zataria multiflora Boiss. hydroalcoholic leaf extract [ZHLE] on isolated rat uterus in presence of some known uterus stimulants. Pieces of virgin adult rat uterus were mounted in an organ bath containing Tyrode or De Jalon solutions. Uterus contraction was induced by KCI, oxytocin and BaCl2 in presence and absence of certain concentrations of ZHLE. In the oxytocin studies, animals received an injection of oestradiol valerate [5mg/kg, S.C.] 24h prior to the experiment. ZHLE [0.125, 0.25, 0.5, 1 and 2 mg/ml] relaxed the uterus precontracted by KCI [60mM] in a dose-dependent manner [P<0.0001] and at 2mg/ml attenuated the BaCl[2] [4mM]-induced uterus contraction [P<0.001]. The inhibitory effect of ZHLE on KCl-induced uterus contraction was unaffected by propranolol [1microM]. In normal De Jalon solution, ZHLE [0.125, 0.25, 0.5, and Img/ml] reduced the oxytocin [10mU/ml]-induced contraction dose-dependently [P<0.0001] but in Ca[2]+-free De Jalon solution, the stimulatory effect of oxytocin was lesser nevertheless, the inhibitory effect of ZHLE was higher. In presence of atropine [0.5microM], acetylcholine [0.5microM] was failed to induce contraction but KCI [30mM] evoked contraction and the extract diminished the contractile response of KCI. The spasmolytic effect of extract [2mg/ml] on KCl-induced contraction was unaffected by naloxone [ImicroM]. From the obtained results it may be concluded that, the ZHLE may induce the inhibitory effect through blockage of the voltage dependent calcium channels and releasing calcium from intracellular stores in rat uterus smooth muscle. The ineffectiveness of propranolol and naloxone on ZHLE inhibitory effect indicates that adrenergic and opioid agonist substance[s] does not exist in the extract. It seems that there is no anticholinergic substance[s] in the extract. The results support the usage of this plant in traditional medicine
ABSTRACT
Reports have shown the antioxidant, hypotensive, hypolipidemic and vasodilatory effects of grape [Vitis vinifera L.] seed extract. We have recently shown the relaxatory effect of grape leaf extract on rat uterus and reduction of frog heart rate and contractility. The aim of the present study was to investigate the relaxant effect of Vitis vinifera leaf hydroalcoholic extract [VLHE] on rat thoracic aorta contractions induced by phenylephrine and KCl and the role of aorta endothelium on this action. Rat aorta was removed and placed in an organ bath containing Krebs-Henseleit solution and aorta contractions were recorded isometrically. The results demonstrate that VLHE [0.125-2 mg/ml] reduces the endothelial intact aorta reconstructed by phenylephrine [1 micro M] dose-dependently [P<0.0001]. Extract induced the same response in endothelial denuded aorta, but in a much lesser extent. The IC50 for both groups were 0.45 +/- 0.08 and 1.73 +/- 0.23 mg/ml, respectively. However, the contractile responses of these groups were similar. VLHE [0.125-2 mg/ml] reduced the contractions induced by KCl [80 mM] dose-dependently [P<0.0001]. The relaxatory effect of VHLE on KCl_induced contractions was less than those evoked by Phenylephrine. Vasorelaxatory effect of VHLE on intact aorta was attenuated by nitric oxide synthase inhibitor [L-NAME, 100 microM] and gaunyl cyclase inhibitor [methylene blue, 10 microM] significantly, but was unaffected by atropine [1 microM]. The results suggest that the greatest vasorelaxant effect of VHLE on rat aorta is endothelium-dependent and nitric oxide [NO] and cGMP are mostly responsible but cholinergic receptors are not involved