[Effect of hydroalcoholic extract onion [allium cepa L.] peel of on the male rat ileum contractility]

Onion [Allium cepa] bulb from Liliaceae has antioxidant, spasmolytic and antihypertensive activities. The goal of this study was to investigate the effect of onion peel extract on the rat ileum contractility. Onion peel powder was extracted by maceration in 70% alcohol for 72 h. A terminal portion of ileum from Wistar male rat was dissected and its contractions were recorded isotonically in an organ bath containing Tyrode solution [37°C] under 1 g tension. Cumulative concentrations of the extract [0.1, 0.2, 0.4 mg/ml] reduced the ileum contractions induced by KCl [60 mM] and by carbachol [10 micro M] dose-dependently [p<0.0001]. The spasmolytic effect of extract was not reduced by tissue incubation with propranolol [1 micro M, 30 min], naloxone [1 micro M, 30 min], L-NAME [100 micro M, 20 min], glibenclamide [10 micro M, 5 min] and neither by tetraethylammonium [1mM, 5 min]. In Ca[2+]-free with high K+ [60mM] Tyrode solution, the extract [0.0125-0.1mg/ml] reduced the ileum contractions induced by cumulative concentrations of CaCl2 [0.225-2.7 mM] dose-dependently [p<0.05-p<0.01]. Onion peel extract reduced the ileum contraction, however, neither the beta -adrenoceptors opioid receptors, nor the potassium channels activation were involved in this activity. It seems that the voltage dependent calcium channels are involved in the spasmolytic effect of the extract. Nevertheless, the quercetin extract might be responsible for this activity

[Antispasmodic effect of Teucrium polium leaf extract on rat ileum]

Teucrium polium [locally called as chez or kalporeh in Khuzestan Province, Iran] is used traditionally as a remedy for treatment of headache, convulsion and dysmenorrhea and moreover, its hypoglycemic, hypolipidemic and antibacterial effects have been reported in recent researches. In addition, it is also used traditionally to treat gastrointestinal disorders. The aim of the present study was to investigate the effects of Teucrium polium aqueous leaf extract on rat ileum contractions evoked by receptor and non-receptor stimulants and also to study the mechanism[s] involved. Freshly dried leaves of Teucrium polium were extracted with boiling water. Pieces of ileum from adult male Wistar rat were mounted in an organ bath containing Tyrode solution and an isotonic transducer recorded contractile responses under 1g initial tension. Data indicate that cumulative concentrations of the extract [0.25, 0.5, 1, 2, 4 and 8 mg/ml] reduced the ileum contractions induced by KCl [60 mM] and acetylcholine [1 microM] in a dose-dependent manner [P<0.0001]. The spasmolytic effect of the extract on KCl-induced contraction was more potent than on the ACh-induced contractions. The spasmolytic effect of extract was totally reversible. The spasmolytic effect of the extract was not affected by L-NAME [100 microM, 20min] in KCl-induced contractions. Spasmolytic effect of extract was not reduced by ileum incubation [30 min] with propranolol, phentolamine and naloxone [all at 1microM] in KCl-induced contractions. The cumulative concentrations of calcium evoked contractions in a dose dependent manner in Ca[2+]-free Tyrode solution with high potassium. These contractions were attenuated by the extract, significantly. The results suggested that the voltage dependent calcium channels might be involved in spasmolytic effects of Teucrium polium aqueous leaf extract. In this inhibitory effect, however, neither NO, opioid receptors, nor adrenoceptors [alpha and beta] were involved

Spasmolytic effect of Cuscuta pentagona fruit aqueous extract on rat ileum

Cuscuta pentagona [convolvulaceae] has been used in Iran for gastrointestinal disorders. The aim of the present study was to investigate the effect of Cuscuta pentagona fruit aqueous extract [CPE] on rat ileum contractility. The fruit extract was prepared according to the traditional method by boiling the fruits in distilled water. Ileum was dissected from adult male Wistar rat, mounted in an organ bath [10 ml] containing Tyrode solution [37°C, pH 7.4]. I leal contractions were recorded under 1 g initial tension, by an isotonic transducer. In many in-vitro studies, potassium chloride and acetyl cholin induced contractions of rat ileum in the absence or presence of some antagonists had been assessed. In some in vivo studies gastrointestinal transit time in different groups of rats after administration of saline, three doses of fruit extract or atropine, had been measured. Cumulative concentrations of CPE [0.5-8 mg/ml] reduced the ileal contractions induced by KC1 [60 mM] and ACh [1 microM] revealing a dose dependent effect [p<0.0001]. The spasmolytic effect of CPFAE was not reduced after 20-30 minutes of tissue incubation with phentolamine [ImicroM], propranolol [lmicroM] L-NAME 100 microM] and naloxone [1 microM]. In.a Ca[2+]-free Tyrode solution the ileum depolarized by KC1, 120 mM was contracted by addition of cumulative concentration of CaCl[2] [0.225 to 3.6 mM] but CPE [2 and 4 mg/ml] reduced the contractions in a dose dependent manner [p<0.0001]. Furthermore, fruit extract in concentrations of 250, 500 and 750 mg/kg [p.o.] reduced the transit time of charcoal meal in small intestine in a dose dependent manner. Our results suggest that the CPE spasmolytic effect is mediated via calcium channels without involvement of adrenoceptors [alpha and beta] or opioid receptors or any influence on NO synthesis. The results of the present study showed that Cuscuta pentagona fruit aqueous extract reduces rat ileum motility in both in vivo and in vitro studies

[Effect of chronic psychological stress on carbohydrate metabolism in rat]

Several studies have shown that stress has major effects on carbohydrate metabolism. There are some evidences suggesting that stress may induce type 1 and type 2 diabetes mellitus. The effects of psychological stress however need to be investigated. The present study has investigated the role of chronic psychological stress on carbohydrate metabolism in male rats. Animals were assigned in two groups of control and stressed [n=8/group]. The animals of the stressed group were exposed to different restraint stressors [1 hour twice daily] for 15 and 30 days. At the beginning and end of the experimental periods fasting blood samples were obtained by tail snipping and oral glucose tolerance test [OGTT] was carried out. Glucose was measured by glucose oxidase method. Insulin and corticosterone were assayed by their respective RIA kits. Fasting plasma glucose level on the 15th day of the experiment showed significant increase in the stressed rats compared to the controls. The plasma levels of glucose at 15 and 60 min after performing OGTT were significantly increased on the 15th and 30th days of the experiment in the stressed group. Fasting plasma insulin showed significant decrease on the 15th and 30th days of the experiment in the stressed group compared to the controls. On the 15th day of the experiment, at 15 and 60 min after performing OGTT the plasma level of insulin showed significant decrease in the stressed group as compared to the control group. Fasting plasma corticosterone concentration was significantly increased on the 15th day of the experiment in the stressed rats compared with the control rats and the 1st day of the experiment. In the stressed group immediately after stress exposure plasma corticosterone was significantly higher than before stress exposure, only on the 1st day of the experiment. Results have revealed that chronic psychological stress can impair glucose metabolism and this effect may be mediated by changes in insulin and corticosterone secretion. However the role of other stress hormones has to be investigated

[Spasmolytic activity of Piper nigrum fruit aqueous extract on rat nonpregnant uterus]

Piper nigrum [Black pepper] from Piperaceae is main constituent of food spice and piperine as its main component increases bile and small intestine secretions, but reduces the gastric emptying and increases intestine transit time in rat and mouse. In traditional medicine, black pepper is used for relief of menorrhalgia in women but this effect has not been evaluated scientifically. The study was performed to investigate the effect of black pepper fruit aqueous extract on rat non-pregnant uterus contractions and the mechanism[s] of its action. Aqueous extract of black pepper was prepared by adding 10 g of black pepper powder to 200 ml of boiling distilled water for 15 min and after filtering, solvent was evaporated. Uterus was dissected from non-pregnant adult rat [Wistar] and in an air bubbled De Jalon solution; contractions were recorded isometrically under 1 g tension. Cumulative concentrations of black pepper aqueous extract [0.125, 0.25, 0.5, 1 and 2 mg/ml] reduced the uterus contractions induced by KCl [60mM] and oxytocin [10mU/ml] dose dependently [p<0.0001]. The spasmolytic effect of extract on the KCl-induced contractions was unaffected by L-NAME [100 micro M] but rather increased by phentolamine [1 micro M] and naloxone [1 micro M]. However, propranolol [1 micro M] reduced the extract spasmolytic effect significantly [p<0.01-p<0.0001]. In calcium free De Jalon solution with high potassium [60mM], extract [0.0312, 0.625, 0.125 and 0.25 mg/ml] reduced the contractions induced by cumulative concentrations of calcium chloride [0.1-0.5mM] dose dependently [p<0.05- p<0.0001]. Our results suggest that the spasmolytic effect of black pepper aqueous extract on rat uterus was mediated via voltage dependent calcium channels and also beta-adrenoceptors could be involved in this action. However, the alpha-adrenoceptors, opioid receptors and nitric oxide generation were not involved. Our results may support the usage of black pepper for relief of menorrhalgia in women

[Spasmolytic effect of Teucrium polium on virgin rat uterus]

Teucrium polium [locally known as chez or kalporeh in Khuzestan Province, Iran] is used traditionally as remedy for treatment of headache, convulsion and dysmenorrheal; and also its hypoglycemic, hypolipidemic and antibacterial effects has been reported. But its spasmolytic effect on uterine smooth muscle remained to be identified. The aim of the present study was to investigate the effect of Teucrium polium aqueous extract [TPAE] on virgin rat uterus contractions evoked by some stimulants. Freshly dried aerial parts of plant were extracted. Contractile responses were recorded isometrically in an organ bath containing Tyrode's or De Jalon solutions under 1g initial tension. Results indicated that extract [0.125, 0.25, 0.5, 1, 2, 4 and 8 mg/ml] reduced the uterus contractions induced by KCl [60mM], oxytocin [10mU/ml] and BaCl2 [4mM] dose dependently and significantly [P<0.0001]. The spasmolytic effect of extract was totally reversible in less than 10min. The spasmolytic effect of TPAE was unaffected by L-NAME [300 and 100 microM] in KCl- or oxytocin-induced contractions receptively. Spasmolytic effect of extract was unaffected by propranolol [1microM for 5 min] in KCl-induced contractions but, reduced significantly in oxytocin-induced contraction. In normal calcium De Jalon solution, the contractions-induced by BaCl[2], were more attenuated by extract than in calcium free solution. The data presented seem to suggest that the spasmolytic effect of Teucrium polium aqueous extract is partially induced via blocking the voltage dependent calcium channels and remaining effect is through involvement of the 3-adrenoceptors and stimulating the cAMP synthesis. In this inhibitory effect, NO is not involved

Effect of Anthum graveolens fruit extract on rat uterus contractions

Dill [Anethum graveolens] from Umbelliferae is used traditionally to treat convulsions and increasing milk production. Also, in Darab [Fars Province] and Yazd dill fruit is used traditionally to prevent abortion. Its antimicrobial, antihyperlipidaemic, anti-hypercholesteroaemic effects and reducing gastric acid secretion have been reported. The aim of the present study was to investigate the effects of dill fruit hydroalcoholic [DFHE] extract on virgin rat uterus contractions induced by KCI [60mM] and oxytocin [10 mU/ml]. Macerated method was used for extract preparation. Virgin Sprague Dawley female rats were pretreated with an injection of estradiol valerate [5mg/kg, s.c.] 24 hours prior to experiment. Rats were killed and uteri were dissected and mounted in an isolated organ bath containing De Jalon solutions [29°C] bubbled by oxygen. Contractile responses were recorded isometrically under 1g initial tension. The DFHE [0.5, 1, 2, 4 and 8 mg/ml] relaxed both KC1- and oxytocin-induced contractions dosedependently [p<0.0001]. However, the spasmolytic effect of extract on oxytocin-induced contractions was more potent. In Ca[2+] -free, rich K+ [120mM] De Jalon solution, cumulative adding of calcium [0.15, 0.3, 0.6, 1.2 and 2.4 mM], increased contractions dose dependently [p<0.0001]. DFHE [4 mg/ml] shifted this dose-response curve to the right [p<0.05]. In Ca[2+] free solution, oxytocin induced strong contractions if calcium [0.3 mM] was added to the bath. However, DFHE [8 mg/ml] reduced calcium-induced contraction [p<0.001]. The spasmolytic effect of DFHE was reversible. The spasmolytic effect of DFHE [4 mg/ml] was affected neither by propranolol [1micro M] nor by L-NAME [100 micro M]. These results suggest that the relaxatory effect of DFHE on KCI and oxytocin-induced uterus contractions is due, at least in part, to blockade voltage dependent calcium channels and partly by disturbing in releasing calcium from intracellular pool indirectly. In addition, the beta-adrenoceptors and NO are not involved in this inhibitory effect of DFHE. Our results may also support the traditionally usage of dill fruit for preventing abortion