Reduction of agonist‐induced contractions of guinea‐pig isolated ileum by flavonoids

Abstract

The effect of 13 flavonoids on the contraction of guinea-pig isolated ileum induced by prostaglandin E2 (PGE2) and leukotriene D4 (LTD4) have been investigated. Apigenin, quercetin and kaempferol at a concentration of 10-mu-M significantly (p < 0.001) reduced the contraction to either agonist. Crysin and flavone antagonized only PGE2 (p < 0.01). The other flavonoids were inactive. The blocking effect of apigenin, quercetin and kaempferol against PGE2 was also concentration- and time-dependent, and was augmented by the calcium channel blocker verapamil or by lowering the extracellular calcium to 25%, consistent with a calcium-mediated mechanism of protection which these flavonoids, at the same concentration, also showed against barium chloride (BaCl2)- or acetylcholine (ACh)-induced contraction (p < 0.05-0.001)

Modification of abomasum contractility by flavonoids present in ruminants diet: in vitro study

“…The antispasmodic effect of quercetin (10 and 100 μM) observed when the specimens were exposed numerous times to this flavonoid (Figure 3b) and spasmolytic effect of apigenin (0.1 to 100 μM) on bovine abomasum are in general agreement with the relaxant activity described previously in various gut preparations, such as mice stomach (Amira et al, 2008), guinea-pig ileum (Capasso et al, 1991a and1991b;Morales et al, 1994), rat ileum (Hammad and Abdallal, 1997), rabbit jejunum (Ghayur et al, 2007) and the results of in vivo studies (Di Carlo et al, 1993). Nevertheless, a dual effect of quercetin, spasmogenic in low doses and spasmolytic in high concentrations recalls analog observations.…”

“…This data justifies the assumption that most flavonoids might reach the GI smooth muscle tissue. Based on the results of in vitro studies carried out on different smooth muscle tissues (Capasso et al, 1991a and1991b;Duarte et al, 1993;Morales et al, 1994;Je et al, 2014) and in vivo observations (Di Carlo et al, 1993 and it might be hypothesized that flavonoids present in ruminant diet affect bovine GI smooth muscle. Therefore, the aim of the study at hand was to evaluate the effect of selected flavonoids on the motoric activity of bovine isolated abomasum specimens.…”

“…Possibly the contractile effect of quercetin and luteolin used in low doses was missed by some authors who studied the effect of those flavonoids on smooth muscle contractility only in the range of doses 1 to 100 μM (Capasso et al, 1991a and1991b;Hammad and Abdalla, 1997; Amira et al, 2008). Still, the results presented herein that refer to the use of flavonoids in high concentrations are in general agreement with data collected by other authors (Capasso et al, 1991a and1991b;Ghayur et al, 2007;Amira et al, 2008). Besides, plants' extracts containing flavonoids may cause variable effects dependent on the applied dose.…”

Effects of two medicinal plants Psidium guajava L. (Myrtaceae) and Diospyros mespiliformis L. (Ebenaceae) leaf extracts on rat skeletal muscle cells in primary culture

“…Flavonoids existing in the extracts could play an (Havsteen, 1983;Capasso et al, 1991) and antidiarrhoeal (Tona et al, 1999) activities. Flavonoids have been reported to have free radical scavenger properties (Bharani et al, 1995).…”

Antimicrobial, antioxidant and calcium channel blocking activities of <i>Amberboa divaricata</i>

“…Previously it has been described that phenolic compounds and some flavonoids have effects on intestinal motility both in vivo and in vitro (Di carlo et al, 1999). Flavonoids such as quercitin has well documented antispasmodic effects on gastrointestinal smooth muscles and some researchers also conclude that this antispasmodic effect is related to calcium release from intracellular stores and/ or interference with calcium entry through calcium channels (Capasso et al, 1991). A much recent study described that flavonoids contained in hexane extract of Syzygium Samarangense exhibited relaxant activity which was due to the blockade of calcium influx (Ghayur et al, 2006).…”