Extract-induced muscle contraction

Small doses of garlic are purported to increase the tone of smooth muscle in the gastrointestinal tract, while large doses decrease such actions (Tyler, 1993). An ethanol—chloroform extract of fresh bulb antagonized acetylcholine and prostaglandin E induced rat fundus smooth muscle contraction at a concentration of 0.002 mg/mL however, an ethanol extract of fresh garlic bulb caused rat fundus smooth muscle stimulation at a concentration of 0.016 mg/mL (Ross, 1998). 

Furthermore, the giant type extract produced the contraction of the longitudinal smooth muscle of the isolated guinea-pig ileum in a dose-dependent manner. The giant type extract at the concentration of 1 pg/ml produced 50 % contraction of the maximum contraction induced by 40 mM KCl in lower doses against the normal type extract (3 pg/ml) (data not shown). 

Smooth muscle relaxant activity. Hexane extract of the dried fruit, administered to guinea pigs at a concentration of 0.15 mg/ mL, was active on bladder and ileum vs KCl-induced contractions R . Administration to... 

Ryania consists of the powdered stem of the tropical shrub, Ryania speciosa. The extract contains ryanodine and related compounds, and has a low toxicity to mammals. The powder is used as a stomach poison on vegetables and fruit. Ryanodine induces paralysis in insects by direct action on the muscles, resulting in sustained contraction and paralysis. 

Aniseed is used in folk medicine as an antispasmodic agent. Tirapelli et al. (2007) report that ethanokwater (40 60) extract of aerial parts of anise (50pg/ml) inhibited acetylcholine-induced contraction in rat smooth muscle. 

The presence of proctolin in the reproductive tract of a variety of insects and the action of this peptide on such tissues has been a current focus for many studies. The visceral muscles of the oviducts of Locusta migratoria. for example, are remarkably sensitive to proctolin (30)- Amounts of the peptide as low as 2 fmol induce a tonic contraction that is dose-dependent up to 200 fmol. A proctolin-like immunoreactive substance was found in the axons of nerves leading to the oviduct as well as in a number of cell bodies in the Vllth abdominal ganglion. Moreover, reverse-phase HPLC of tissue extracts of oviducts, oviducal nerves, and the Vllth abdominal ganglia indicate that the proctolin-like bioactive substance co-elutes with authentic proctolin. The peptide was present in areas of the oviduct that receive extensive innervation while it was ten-fold less in areas that receive little or no innervation. 

Tortoriello and Aguilar-Santamaria [120] investigated in detail the spasmolytic mechanisms of action of one of these plants, B. serraefolia. The results suggest that the extract does not interact with classical receptors and its effects, at least that produced on smooth muscle, may be due to a probable interference with calcium influx and/or calcium release from an intracellular store. Different chemical compounds, such as clerodane diterpenes and flavonoids, which are typical constituents from the Baccharis genus, have been considered as the active principles of many spasmolytic drugs. A bioassay-monitored fractionation of an extract from B. genistelloides yielded a mixture that blocked the calcium-induced contractions of KCl-depolarized rat portal vein preparations [121], Pharmacological tests of two pure compounds isolated from the mixture revealed a dilactonic clerodane-diterpene, Fig. (70) as the active compound. 

Lemos et al. studied the nonspecific and reversible smooth muscle relaxant activities of the ethanol extract of A. papillaris (EE), a fraction containing tertiary alkaloids (TAF) and three alkaloids isolated from it [120]. In non pregnant rat uterus, EE and TAF inhibited both the oxytocin-induced contractions and the amplitude of rhythmic spontaneous contractions with the IC50 values of 0.91 and 0.22 pg/ml in the first experiment and 1.0 and 0.17 pg/ml in the second, respectively. The rythmic contractions of the uterus obtained from 21-day pregnant rats... 

Figure 111.4 Isometric twitch contraction times. Time to peak twitch force (a) and half relaxation time of twitch force (b) are plotted for rat diaphragm muscle strips. Hypothyroidism was induced for 3 months in the rats prior to tissue extraction and in vitro evaluation. Hypothyroidism resulted in prolonged time to peak twitch force and half relaxation time. lndicates statistically significant difference from control muscle strips (p < 0.05). Error bars are SEM.

Kassinin, DVPKSDQFVG LMa, a 12-peptide amide belonging to the tachykinin family. Kassinin was isolated from methanol extracts of the skin of the African frog Kassina senegalensis in 1977. It causes contraction of smooth muscle preparations at an activity of only 0.5% compared with substance P. The aqueous- and lipid-induced structure of kassinin has been studied using 2D H-NMR [A. Anastasi et al., Experientia 1977, 33, 857 R. C. Grace etal.,J. Biomol. Struct. Dyn. 2001, 18, 611]. 

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