• Analytical Science and Technology
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• v.6 no.4
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• pp.395-399
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• 1993

Corynoxeine, rhynchophylline, isocorynoxeine, isorhychophylline were isolated from Uncaria hooks and determined by HPLC. Their contents were : isocorynoxeine 0.21%, isorhynchophylline 0.16%, corynoxeine 0.28%, rhynchophylline 0.23%, respectively. Corynoxeine and isocorynoxeine, rhynchophylline and isorhychophylline were interconverted each other by heat treatment.

• Natural Product Sciences
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• v.22 no.4
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• pp.263-269
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• 2016

Rhynchophylline (RP) is a major tetracyclic oxindole alkaloid of Uncariae Ramulus et Uncus which has been used to treat hypertension, seizures, pain and anxiety in the oriental countries. A recent report revealed that RP attenuated ischemia-induced neuronal damage and kainite-induced convulsions in animals. This study was performed to investigate whether RP enhances pentobarbital-induced sleep behaviors and modulates sleep architecture in mice. Locomotor activity was significantly inhibited by RP at 0.25 and 0.5 mg/kg, similar to 2 mg/kg diazepam (a benzodiazepine agonist) in mice. RP shortened sleep latency and increased total sleep time in a dose-dependent manner when administrated with pentobarbital (42 mg/kg, i.p.). RP also increased the number of sleeping mice and total sleep time by concomitant administration with the sub-hypnotic dosage of pentobarbital (28 mg/kg, i.p.). On the other hand, RP (0.25 mg/kg, p.o.) itself significantly inhibited sleep-wake cycles, prolonged total sleep time, and rapid eye movement in rats. In addition, RP also increased chloride influx in the primary cultured hypothalamic neuronal cells. In addition, we found that glutamic acid decarboxylase ($GAD_{65/67}$) was activated by RP. In conclusion, RP augments pentobarbital-induced sleeping behaviors, and can be a candidate for treating insomnia.

• Biomolecules & Therapeutics
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• v.12 no.3
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• pp.138-144
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• 2004

Therapeutic effect of a Kampo medicine, Choto-san, in patients with vascular dementia was demonstrated by a double-blind and placebo-controlled clinical trial. To clarify the therapeutic efficacy of Choto-san, anti-ischemic effect in mice, hypotensive effect in spontaneously hypertensive rats (SHR), anti-oxidative effects in vitro, and N-methyl-D-aspartate (NMDA) receptor-blocking activity using Xenopus oocytes were studied. (1) Pretreatment with Choto-san (0.75-6.O g/kg, P.O.) or a component herb Chotoko (Uncaria genus: 75 - 600 mg/kg, P.O.) prevented ischemia-induced impairment of spatial learning behaviour in mice. Indole alkaloids- and phenolic fractions extracted from Chotoko also improved significantly the learning deficit. (2) Subchronic administration of Choto-san (0.5 g/kg, p.o.) caused a significant hypotensive effects in SHR. (3) Choto-san, Chotoko, and the phenolic constituent, (-) epicatechin, significantly protected the NG108-15 cell injury induced by $H_20_2$ exposure in vitro and also inhibited lipid peroxidation in the brain homogenate. (4) Indole alkaloids, rhynchophylline and isorhynchophylline (1-100 uM), reversibly reduced NMDA-induced current in the receptor-expressed Xenopus oocytes. These results suggest that anti-vascular dementia effects of Choto-san are mainly due to the effect of Chotoko. From these results, it is possible to make a novel dietary supplement through several extraction steps from Chotoko.