Positive inotropic action of saponins on isolated atrial and papillary muscles from the guinea‐pig

Abstract

The effects of several saponins of animal and plant origin on the contractile activity of atrial and papillary muscles of the guinea‐pig were tested. In a concentration of 1 × 10−5 M, holothurin‐A (HL‐A), holothurin‐B, echinoside‐A, echinoside‐B and sakuraso‐saponin (Saku) exhibited positive inotropic and chronotropic actions whereas desacyl‐jego‐saponin and ginsenoside‐Rd did not. Saponins having a positive inotropic action caused haemolysis of rabbit erythrocytes whereas those without inotropic action did not cause haemolysis. The positive inotropic action of saponins was not affected by practolol, chlorpheniramine, cimetidine and indomethacin. Verapamil (10−6 M) inhibited the inotropic actions due to HL‐A and isoprenaline (10−8 M) to the same extent but had a small efect on those due to ouabain (10−7 M). In high K+ (30 mM K+) medium where the action potential and the contraction were depressed, HL‐A, Saku and isoprenaline restored the action potential and the contraction of the ‘slow response’ type whereas ouabain failed to do so. In normal medium HL‐A and Saku reduced the resting membrane potential by 15–20 mV. These results suggest that modification of the Ca channel is involved in the positive inotropic action of saponins.

The biological action of saponins in animal systems: a review

“…Membrane fluidity controls the enzyme activity of biological membranes and has an important role in ion transport (Ma & Xiao, 1998) and the ability of saponins to affect this parameter may explain their effects on cellular function. The inotropic action of saponins, supposed to be caused by their effect on membrane Ca 2+ channels, also did not have any simple correlation with membrane permeability effect (Enomoto et al 1986). Saponins such as ophiopogonins and ginsenocides haemagglutinated human, rabbit, and sheep erythrocytes but were not haemolytic (Takechi & Tanaka, 1995a).…”

Structural characteristics, bioavailability and cardioprotective potential of saponins

“…Enomoto et al (1986) studied the positive inotropic effect of saponins of Panax species and concluded that modification of calcium channel might be involved in this effect. 68 Saponins with positive inotropic effect were showed haemolysis in rabbit erythrocytes. A cardioactive steroidal saponin containing rare neogetogenin as aglycon named cistocardin from Ayurvedic medicinal plant Tribulus cistoides (thistle of the hot country) exhibited strong positive inotropic effect at 10 −6 M to 10 −5 M concentration in papillary muscles of Guinea pigs.…”

Separation of two main triterpene glycosides from sea cucumberPearsonothuria graeffeiby high-speed countercurrent chromatography

“…Sea cucumber has been a traditional healthy food for thousands of years. Triterpene glycosides are the most important secondary metabolites of sea cucumbers because of their biological activities, including antifungal, cytotoxic, hemolytic, cytostatic, and immunomodulatory effects [1][2][3][4]. More than 100 of these compounds have been isolated from sea cucumbers.…”