hirsuteine and hirsutine

Hirsutine and hirsuteine are the main pharmacological activity ingredients of Uncaria rhynchophylla (UR), playing an important role in treating mental and cardiovascular diseases, such as Alzheimer's disease, hypertension, Parkinson's disease, potential anti-cancer activities and so on.. To develop a cyclodextrin-modified micellar electrokinetic capillary chromatography (CD-MEKC) method for the simultaneous separation and determination of hirsutine and hirsuteine from UR and its formulations.. The optimal method was developed by investigating influences of significant factors on the separation, and this method was successfully applied for the determination of hirsutine and hirsuteine in UR and its formulations.. The optimal background electrolyte (BGE) consisted of 40 mM sodium dihydrogen phosphate (pH 7.0), 150 mM 2,6-dimethyl-β-cyclodextrin (DM-β-CD), 3 mM mono-(6-ethylenediamine-6-deoxy)-β-cyclodextrin (ED-β-CD), and 30 mM sodium cholate (SC). Under these conditions, hirsutine and hirsuteine were successfully separated within 13 min at the separation voltage of 15 kV, temperature of 25°C and the detection wavelength of 224 nm. For the analytes, linear calibration curves were performed within the range 5.0-160.0 μg/mL. The limit of detection (LOD, S/N = 3) and the limit of quantitation (LOQ, S/N = 10) were 0.41, 1.42 μg/mL for hirsutine and 0.60, 2.17 μg/mL for hirsuteine, respectively. The recoveries of three samples were from 97.9% to 102.3%.. The method was successfully applied to the determination of hirsutine and hirsuteine in UR and its formulations. Meanwhile, it provides an effective reference of the quality control of UR and its formulations.

Topics: Alkaloids; Chromatography, Micellar Electrokinetic Capillary; Cyclodextrins

One new alkaloid, 4-geissoschizine N-oxide methyl ether (1), was isolated from the EtOH extract of the hook-bearing branch of Uncariarhynchophylla, together with 10 known alkaloids, 3-epi-geissoschizine methyl ether (2) isolated from U.rhynchophylla for the first time, geissoschizine methyl ether (3), 4-hirsuteine N-oxide (4), hirsuteine (5), hirsutine (6), 3α-dihydro-cadambine (7), 3β-isodihydro-cadambine (8), cadambine (9), strictosamide (10), and akuammigine (11). The structures were elucidated by spectroscopic methods including UV, ESI-QTOF MS, NMR, and circular dichroism experiments. Neuroprotective effects of 1-9 were investigated against 3 mM glutamate-induced HT22 cell death. The activity assay showed that 2, 3, 5, and 6 exhibited potent neuroprotective effects against glutamate-induced HT22 cell death. However, only weak neuroprotective activities were observed for 1, 4, 7, 8, and 9.

Topics: Alkaloids; Cell Death; Cell Survival; Drugs, Chinese Herbal; Glutamic Acid; Indole Alkaloids; Molecular Structure; Neuroprotective Agents; Nuclear Magnetic Resonance, Biomolecular; Uncaria

Effects of the kampo medicine yokukansan on gene expression of the cystine/glutamate antiporter system Xc-, which protects against glutamate-induced cytotoxicity, were examined in Pheochromocytoma cells (PC12 cells). Yokukansan inhibited glutamate-induced PC12 cell death. Similar cytoprotective effects were found in Uncaria hook. Experiments to clarify the active compounds revealed that geissoschizine methyl ether, hirsuteine, hirsutine, and procyanidin B1 in Uncaria hook, had cytoprotective effects. These components enhanced gene expressions of system Xc- subunits xCT and 4F2hc, and also ameliorated the glutamate-induced decrease in glutathione levels. These results suggest that the cytoprotective effect of yokukansan may be attributed to geissoschizine methyl ether, hirsuteine, hirsutine, and procyanidin B1 in Uncaria hook.

Topics: Alkaloids; Amino Acid Transport Systems, Acidic; Animals; Cell Death; Drug Evaluation, Preclinical; Drugs, Chinese Herbal; Fusion Regulatory Protein 1, Heavy Chain; Gene Expression Regulation; Glutamates; Glutathione; Indole Alkaloids; Medicine, Kampo; PC12 Cells; Protective Agents; Rats

The metabolic fate of hirsuteine (HT) and hirsutine (HS), the major indole alkaloids of Uncaria rhynchophylla, was investigated using rats. On HPLC analysis, urine from rats orally administered HT were found to contain two metabolites (HT1 and HT2) together with unchanged HT. Similarly HS also was metabolized to two compounds (HS1 and HS2). Metabolite structures were determined to be 11-hydroxyhirsuteine-11-O-beta-D-glucuronide (HT1), 11-hydroxyhirsuteine (HT2), 11-hydroxyhirsutine-11-O-beta-D-glucuronide (HS1) and 11-hydroxyhirsutine (HS2), based on spectroscopic and chemical data. HT1 and HS1 were also detected in bile from rats administered HT and HS, respectively. Total cumulative urinary excretion within 72 h of oral administration was approximately 14% and 26% of the HT and HS doses, respectively, while total cumulative biliary excretion was 35% and 46%, respectively. HT and HS 11-hydroxylation were catalyzed by rat liver microsomes. This 11-hydroxylation activity was inhibited by addition of SKF-525A (a nonselective CYP inhibitor) or cimetidine (a CYP2C inhibitor). These results indicate that orally administered HT and HS are converted to 11-hydroxy metabolites in rats, and that the metabolites are predominantly excreted in bile rather than urine following glucuronidation. Furthermore, the results suggest that CYP2C enzymes are involved, at least in part, in the specific 11-hydroxylation of HT and HS.

Topics: Alkaloids; Animals; Chromatography, High Pressure Liquid; Hydroxylation; Magnetic Resonance Spectroscopy; Male; Rats; Rats, Sprague-Dawley; Spectrophotometry, Infrared; Uncaria

The crude drug, Chotoko (Uncariae Uncis cam Ramlus), the hooks of Uncaria spp. (Rubiaceae), has been claimed to possess sedative and anti-spasmodic actions, and is contained in a Chinese traditional preparation, Choto-san, as a main crude drug. Examinations were made on the anti-convulsion effects of Choto-san and Chotoko against some animal models of epilepsy conducted by the stimulation of drugs or electricity. Oral administration of the Choto-san extract to mice at the doses of 1.0 g/kg and 3.0 g/kg tended to inhibit the glutamate-induced convulsion in a dose-dependent manner, and the effect of the Chotoko extract at a 3.0 g/kg dose was significant, while both the extracts showed no activity against the picrotoxine-induced, strychinine-induced, and electroshock convulsions. The Choto-san preparation without Chotoko was inactive, and the activity of the Chotoko extract was more potent than that of the every crude drug comprising Choto-san, suggesting that Chotoko plays the most important role in the Choto-san prescription and contains some active compounds. Bioassay-guided fractionation of the Chotoko extract led to the location of the active components in the less polar alkaloids-containing fraction, from which three indole alkaloids, geissoschizine methylether (1), hirsuteine (2) and hirsutine (3), and an oxyindole alkaloid, isocorynoxeine (4) were isolated and identified. Oral administration of 1 and 2 to mice at the doses of 50, 100, and 200 mg/kg inhibited the glutamate-induced convulsion in a dose-dependent manner. The effect of 3, the dihydro derivative of 2, was less potent than those of 1 and 2. Compound 4 showed no activity at a 100 mg/kg dose compared with control. The above results support the Chinese herbal description of the anti-spasmodic action of Chotoko, and show that 1 and 2 contained in Chotoko must be mainly contributed to the activity. It is also suggested that Choto-san may be clinically available for treatment of epilepsy.

Topics: Alkaloids; Animals; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Glutamic Acid; Indole Alkaloids; Indoles; Male; Mice; Mice, Inbred Strains; Picrotoxin; Seizures; Strychnine

Vasodilative effects of hirsutine (HS) and hirsuteine (HST) which were isolated from the domestic plant Uncaria rhynchophylla Miq. and beta-yohimbine (beta-Y) which was isolated from the domestic plant Amsonia elliptica Roem. et Schult. were carried out. In the hind-limb artery of anesthetized dogs, intra-arterial administration of HS, HST and beta-Y caused a vasodilatation. The vasodilative potency of HS was somewhat stronger than that of HST, and the potency of both alkaloids was approximately equal to that of papaverine. The vasodilative effect of beta-Y was similar to that of yohimbine, which is considered to be derived from its alpha-adrenoceptor blocking effect, and the potency of both alkaloids was approximately the same, while the effect of beta-Y was stronger than that of papaverine. In the coronary artery, HS showed a vasodilatation and its potency was weaker than that of papaverine. Also, HS showed the same effect in the cerebral artery, and the potency of HS was approximately the same as that of papaverine. These results suggest that the mode of the vasodilative effect induced by HS may partly differ from that of papaverine.

Topics: Alkaloids; Animals; Cerebral Arteries; Coronary Vessels; Dogs; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Female; Leg; Male; Regional Blood Flow; Vasodilation; Yohimbine