Effects of ginsenoside Re on rat jejunal contractility

Abstract

Ginsenoside Re (GRe) exerts diverse effects. Based on our observations, the present study was designed to investigate GRe-exerted bidirectional regulation (BR) on the contractility of isolated jejunal segment. Six pairs of different low and high contractile states of rat jejunal segment were established and used in the study. Stimulatory effects on the contractility of jejunal segment were exerted by GRe (10.0 μM) in all 6 low contractile states, and inhibitory effects were exerted in all 6 high contractile states, indicating that GRe exerted BR on the contractility of jejunal segment. The effects of GRe on the phosphorylation of 20 kDa myosin light chain, protein contents of myosin light chain kinase (MLCK) and MLCK mRNA expression in jejunal segment in low and high contractile states were also bidirectional. GRe-exerted BR was abolished in the presence of neurotoxin tetrodotoxin or Ca2+ channel blocker verapamil or c-Kit receptor tyrosine kinase inhibitor imatinib. Atropine blocked the stimulatory effects of GRe on jejunal contractility in low-Ca2+-induced low contractile state; phentolamine, propranolol and l-NG-nitro-arginine blocked the inhibitory effects in high-Ca2+-induced high contractile state, respectively. In summary, GRe-exerted BR depends on jejunal contractile state and requires the presence of enteric nervous system, Ca2+, and interstitial cells of Cajal; the stimulatory effects of GRe on jejunal contractility are related to cholinergic stimulation and inhibitory effects are related to adrenergic activation and nitric oxide relaxing mechanisms.

Ameliorative effects of atractylodin on intestinal inflammation and co-occurring dysmotility in both constipation and diarrhea prominent rats

“…Atractylodin-induced contractile-state-dependent regulation is not an exception. Our previous studies indicated that ginsenoside Re (four-membered ring), emodin (three-membered ring), and diprophylline (two-membered ring) were also found respectively to have contractile-state-dependent regulation on rat jejunal contractility [495051]. …”

Anti-Inflammatory Response and Muscarinic Cholinergic Regulation during the Laxative Effect of Asparagus cochinchinensis in Loperamide-Induced Constipation of SD Rats

“…Furthermore, saponin as well as extracts containing saponin inhibit the pro-inflammatory responses in cecal ligation, puncture (CLP)-induced sepsis mice, and dextran sulfate sodium (DSS)-induced mouse colitis models [16,17,18]. Ginsenoside Re exerts cholinergic stimulation and inhibitory effects on the contractility of isolated jejunal segments [19,20]. The laxative effects, inflammatory response, and cholinergic regulation of saponin-enriched extracts of Asparagus cochinchinensis (SPA) in the Lop-induced constipation model have not been fully investigated, although seven steroidal saponins were detected in the roots of A. cochinchinensis [21,22].…”

Berberine depresses contraction of smooth muscle via inhibiting myosin light-chain kinase

“…Finally, MLC 20 phosphorylation triggers cycling of myosin crossbridges along with actin filaments, resulting in motive force. [ 6 7 ] To reveal the underlying mechanism of how berberine affects the contraction of smooth muscle, we investigate the effect of berberine on the activity of MLCK, which is a key enzyme involved in the signal pathway related to smooth muscle contraction. Since both phosphorylation level and Mg 2+ -ATPase activity of the myosin are dependent on catalyzation of MLCK, they may be used as a reliable index for measuring the activity of MLCK.…”

“…Finally, MLC 20 phosphorylation triggers cycling of myosin crossbridges along with actin filaments, producing a motive force. [ 7 ] As a result, inhibiting MLCK can effectively depress the smooth muscle contraction.…”