Antispasmodic effect of Tecoma stans [L.] Juss leaf extract on rat ileum

Tecoma stans [L.] Juss or Yellow bells from Bignoniaceae is a ornamental tropical shrub or small tree predominantly found in central, and south America and in Latin America is used traditionally for reducing blood glucose. However, its other pharmacological effects have not been yet elucidated. The aim of present study was to investigate the effect of its leaves extract on rat ileum contractility and involved mechanism[s]. Tecoma stans Juss hydroalcoholic leaf extract [TLE] was prepared by macerated method using 70% alcohol. Distal segment of ileum [2 cm] from male Wistar rat was mounted in an organ bath containing Tyrode solution [10 ml, pH 7, 37 °C] and pre-contracted by carbachol [CCh, 10 micro M] or by KCl [60 mM]. The antispasmodic effects of TLE [0.125-2 mg/ml] were studied prior and after 20-30 min incubation of ileum with propranolol [1micro M], naloxone [1micro M], L-NAME [100 micro M], or 5 min incubation with glibenclamide [10 micro M] and tetraethylammonium [TEA, 1mM]. The effect of TLE on CaCl[2]-induced contraction in Ca[2+] -free with high K[+] Tyrode solution was also studied. The CCh- and KCl-induced ileal contractions were reduced by TLE [P<0.0001]. This effect was not attenuated by propranolol, naloxone, L-NAME, glibenclamide and TEA. In Ca[2+]-free Tyrode solution with high K[+], cumulative concentrations of CaCl2 induced contractions which were inhibited by TLE dose-dependently. Our results indicate that the Tecoma stans [L.] Juss leaf extract induces its antispasmodic effects without involvement beta-adrenoceptors, opioid receptors, potassium channels and NO production. It seems that, the calcium channels are involved in this spasmolytic effect

Spasmolytic effect of Vitis vinifera leaf extract on rat colon

Vitis vinifera [grape] leaf has been used traditionally to treat diarrhea and its extract induces relaxation in rat aorta and uterus. The aim of present study was to investigate the effect of grape leaf hydroalcoholic extract [GLHE] on rat colon contractions induced by some spasmogens. A piece of distal colon from male adult Wistar rats were dissected and mounted in an organ bath containing Tyrode solution and colon contractions recorded by an isotonic transducer under 1g resting tension. The GLHE [0.5- 4 mg/ml] reduced the contractions induced by KCl [60 mM], BaCl2 [4 mM], acetylcholine [1 micro M] dose-dependently [P<0.001]. The spasmolytic effect of GLHE on ACh-induced contraction was unaffected by propranolol [1 micro M], phentolamine [1 micro M], L-NAME [300 micro M], and naloxone [1micro M]. In Ca2+-free but rich in KCl [120 mM] Tyrode solution, cumulative concentrations of CaCl2 induced colon contractions which, were inhibited by the extract. Glibenclamide [3 micro M] had no effect on the extract spasmolytic activity, but tetraethylammonium [5 mM] contracted the pre-relaxed colon induced by the extract. Results suggest that the grape leaf hydroalcoholic extract spasmolytic effect is due to the blockade of the voltage dependent calcium channels and activation of Ca2+-operated potassium channels

[Spasmolytic effect of zataria multiflora boiss leaf extract on rat uterus]

Zataria multiflora Boiss is used in traditional medicine to treat gastrointestinal disorders and menrrhalgia. The inhibitory effect of this herb on rat ileuni contractions has also been reported. The aim of this study was to investigate the effect of Zataria multiflora Boiss hydroalcoholic leaf extract [ZHLE] on isolated rat uterus in the 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 contractions were induced by KCI, oxytocin and BaC1[2] in presence and absence of ZHLE. Animals in oxytocin studies received an injection of oestradiol valerate [5mg/kg, s.c.] 24 h prior experiment. ZHLE [0.125, 0.25, 0.5, 1 and 2 mg/ml] relaxed the uterus precontracted by KC1 [60mM] in a dose-dependent manner [p<0.0001] and at 2mg/mi attenuated the BaC1[2] [4mM]-induced uterus contraction significantly [p<0.001]. The inhibitory effect of ZLHE on KC1-induced uterus contraction was unaffected by propranolol [1 micro M]. in normal IDe Jalon solution, ZHLE [0.125, 0.25, 0.5, and 1 mg/ml] reduced the oxytocin [10mU/ml]-induced contraction dose-dependently [p<0.0001] but in Ca[2+]-free Dc Jalon solution, the stimulatory effect of oxytocin was weaker and also the inhibitory effect of ZHLF was more consistent. In presence of atropine [0.5jiM], acetylcholine [0.5jiM] failed to induce contraction but KC1 [30mM]-evoked contraction and extract diminished the contractile response of KC1. The spasmolytic effect of extract [2mg/ml] on KC1-induced contraction was unaffected by naloxone [1 micro M]. From the obtained results it may be concluded that, the ZHLE may induce its 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 ZLHE inhibitory effect indicates that adrenergic and opoids agonist substance[s] did not exist in the extract. it seems that there was no anticholinergic substance[s] in the extract. The results support the usage of this plant in traditional medicine