stepholidine and tetrahydropalmatine

Topics: Alkaloids; Antipsychotic Agents; Berberine; Berberine Alkaloids; Receptors, Dopamine

To study the effect of tetrahydropalmatine (THP) analogs on Fos protein expression induced by formalin-pain and elucidate analgesic mechanism of THP analogs.. The pain response to Sprague Dawley rats was induced with formalin injected s.c. into the plantar surface of the right hindpaw. Fos protein expression in brain and spinal cord was investigated with immunohistochemistry. The numbers of Fos-like immunoreactive (FLI) neurons were counted with Leica Q570 image analyzer.. In the groups of THP analogs and D2 antagonist spiperone, FLI neurons induced by intraperitoneal (i.p.) injection of THP analogs and spiperone were mainly located in the striatum and accumbens nucleus, and a few FLI neurons were also in sensorimotor cortex. In the D1 antagonist, D1 agonist, D2 agonist, saline and vehicle groups, FLI neurons were seldom seen in the striatum and accumbens nucleus. Moreover, the Fos protein expression induced by l-THP and spiperone could be prevented by the pre-treatment of the D2 agonist quinpirole but not D1 agonist SKF38393. In the formalin-pain group, FLI neurons were mainly distributed in ascending pain afferent system (APAS) and descending pain modulation system (DPMS). Following i.p. THP analogs, however, the numbers of FLI neurons induced by formalin-pain in the APAS, such as dorsal horn (mainly laminae I, II, IV-VI) were markedly decreased, while the numbers of FLI neurons in the DPMS, such as periaqueductal gray (PAG) and reticular paragigantocellular lateral nucleus (RPLN) were significantly increased.. THP analogs enhanced the activity of brainstem DPMS by the blockade of D2 receptors in the striatum and accumbens nucleus, and sequentially inhibited the inputs of peripheral pain afferent message in spinal cord level.

Topics: Analgesics, Non-Narcotic; Animals; Berberine; Berberine Alkaloids; Brain; Dopamine Agonists; Dopamine Antagonists; Formaldehyde; Male; Pain; Proto-Oncogene Proteins c-fos; Quinpirole; Rats; Rats, Sprague-Dawley; Spinal Cord; Spiperone

Seven bio-active alkaloids (stepholidine, sinoacutine, isocorydine, l-tetrahydropalmatine, crebanine, fanchinoline and tetrandrine) in Stephania plants were determined by RP-HPLC, using UV detection (282 nm) and gradient elution. The reversed phase system consisted of ODS column and methanol-water-triethylamine as mobile phase. The flow rate was 1.0 ml.min-1. Good linearity between peak heights and concentrations of the alkaloids was obtained in the concentration range. The HPLC method proved accurate, precise and sensitive. The results showed that there were some differences in the occurrence and content of the alkaloids between various species and between the same species from different habitats and collecting time. Based on the results, some species with high content of the 7 bio-active alkaloids were selected. The study provided some useful information for the utilization of medicinal plant resources in the genus Stephania.

Topics: Alkaloids; Aporphines; Benzylisoquinolines; Berberine; Berberine Alkaloids; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Morphinans; Species Specificity; Stephania

The antagonistic effect of tetrahydroproberberine (THP) homologues on alpha 1-adrenoceptor was studied by combination of radioligand binding assays and measurements of vasoconstriction responses. The results showed that l-tetrahydropalmatine (l-THP), l-stepholidine (l-SPD), THPB-18 and tetrahydroberberine (THB) competitively inhibited the 125I-BE2254 specific binding in rat cerebral cortex with pK1 values of 5.54 +/- 0.36, 5.56 +/- 0.47, 5.75 +/- 0.56 and 6.01 +/- 0.60, respectively, and the Hill efficiency was not significantly different from unity. They inhibited phenylephrine-induced constrictions with pA2 values of 5.48 +/- 0.58, 5.66 +/- 0.54, 5.64 +/- 0.34 and 5.45 +/- 0.76, respectively, and the slopes of Schild plot were not significantly different from unity. The results indicate that the 4 THP homologues are non-subtype selective competitive antagonists for alpha 1-adrenoceptor with similar affinities.

Topics: Adrenergic alpha-Antagonists; Animals; Berberine; Berberine Alkaloids; Binding, Competitive; Male; Rats; Receptors, Adrenergic, alpha-1; Vasoconstriction

Effect of tetrahydroberberine (THB), l-tetrahydropalmatine (THP) and l-stepholidine (SPD) were supposed to be related to the blocking of calcium influx. In this paper, using Fura-2/AM and AR-CM-MIC cation measurement system, the effects of THB, THP and SPD on cytosolic free calcium ([Ca2+]i) in cultured rat single myocardial cells were examined and compared with verapamil (Ver). THB, THP and SPD (10-100 mumol.L-1) were found to increase resting [Ca2+]i gently, which was not depressed by tetrodotoxin. THB, THP and SPD (1-100 mumol.L-1) were also shown to inhibit the KCl-induced [Ca2+]i elevation, the IC50 values of THB and SPD were 50.9 (95% confidence limits: 18.5-140) mumol.L-1 and 23.5 (95% confidence limits 7.6-73.4) mumol.L-1, respectively. THB, THP and SPD 30 mumol.L-1 were also shown to inhibit the elevation of [Ca2+]i induced by high extracellular calcium and norepinephrine; but the inhibitory effects of these drugs were weaker than those of Ver. The three compounds showed no significant effect on ouabain induced [Ca2+]i increase. These results suggest that the inhibitory effects of THB, THP and SPD on [Ca2+]i in myocite by blocking voltage-dependent calcium channels were similar but inferior to Ver.

Topics: Animals; Animals, Newborn; Berberine; Berberine Alkaloids; Biological Transport, Active; Calcium; Calcium Channel Blockers; Cells, Cultured; Myocardium; Rats; Rats, Sprague-Dawley; Verapamil

The effects of (-) SPD and (-) THP on the noradrenergic neurons in rat locus coeruleus were investigated by recording the in vivo spontaneous firing. It was found that (-) SPD could increase the firing frequency of the NE neurons via antagonistic action on alpha 2 autoreceptors in a dose-dependent manner, while alpha 2 receptor agonist clonidine exerted an inhibitory effect. (-) THP induced inhibitory firing of the neurons, however, irreversible.

Topics: Adrenergic Agents; Adrenergic alpha-Antagonists; Animals; Berberine; Berberine Alkaloids; Electrophysiology; Locus Coeruleus; Male; Neurons; Norepinephrine; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, alpha

Topics: Animals; Berberine; Berberine Alkaloids; Dopamine Antagonists; Drugs, Chinese Herbal; Stereoisomerism; Structure-Activity Relationship

The effects of tetrahydroberberine (THB) on ischemic and reperfused myocardium were studied in comparison with verapamil (Ver). In anesthetized rats, THB and its analogues, l-THP and l-SPD, reduced the infarct size after 4 h of left anterior descending coronary artery (LAD) ligation. In Langendorff hearts, in common with Ver, THB 1 and 10 mumol.L-1 markedly decreased the incidences of ventricular tachycardia (VT) and ventricular fibrillation (VF) in the reperfusion period. The malondialdehyde content and xanthine oxidase activity were also decreased in global ischemic-reperfused hearts pretreated with THB (P < 0.01, or P < 0.05). It suggested that THB could protect the myocardium from ischemic and reperfusion injury.

Topics: Animals; Anti-Arrhythmia Agents; Berberine; Berberine Alkaloids; In Vitro Techniques; Male; Malondialdehyde; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocardium; Rats; Rats, Sprague-Dawley; Verapamil; Xanthine Oxidase

The activity of tyrosine hydroxylase by accumulation of L-dopa content in the striatum under decarboxylase inhibitor (benserazide, 400 mg.kg-1) was measured by HPLC-ECD to ascertain whether l-SPD possesses an agonistic or antagonistic effect on D2 receptor subtype. The accumulated L-dopa content was increased with 1,4-butyrolactone (BL, 750 mg.kg-1) to 1.8 +/- s 0.6 micrograms.g-1 in rat striatum. After the rats were ip l-SPD 5 mg.kg-1 or l-tetrahydropalmatine (l-THP) 10-20 mg.kg-1, the increment of L-dopa level was much more than that in the BL group (P < 0.01) in a dose related manner. On the contrary, apomorphine (ip 5 mg.kg-1) abolished the accumulation of L-dopa induced by BL. Furthermore, l-SPD and l-THP not only reversed the negative feed-back regulation by apomorphine on the accumulated level of L-dopa, but also increased this level over the accumulation by BL. These results showed that l-SPD and l-THP do possess the antagonistic effect on presynaptic DA receptor (D2) without agonistic effect.

Topics: Alkaloids; Animals; Apomorphine; Berberine; Berberine Alkaloids; Corpus Striatum; Dopamine D2 Receptor Antagonists; Dose-Response Relationship, Drug; Levodopa; Male; Rats; Rats, Sprague-Dawley; Stereoisomerism

Tetrahydroprotoberberines (THPBs), including (-)-stepholidine ((-)-SPD), (-)-tetrahydropalmatine ((-)-THP) and tetrahydroberberine (THB), have been demonstrated to be a new class of DA antagonists in biochemical and neuropharmacological studies. In this paper, the antagonistic action of THPBs was examined by means of single unit recording from nigral DA neuron in chloral hydrate-anesthetized and gallamine-paralyzed rats. Intravenous injection of these compounds could promptly and completely reverse the inhibition of the spontaneous firing induced by DA agonist apomorphine (APO) in a dose-dependent way. Pretreatment with (-)-SPD, (-)-THP or THB could significantly reduce the inhibitory effect of APO and shift the dose-action curve to the right. Besides, the compounds could increase the spontaneous firing of DA neurons. The above results not only strongly support the conclusion that (-)-SPD, (-)-THP and THB are DA antagonists, but also demonstrate that one of their blocking sites is at somatodendritic DA autoreceptors (D-2 receptors). In other words, (-)-SPD did not exhibit any DA agonistic action in this acute electrophysiological study, although its DA agonistic action can be demonstrated in rotational behavior of 6-OHDA-lesioned rats. The dual actions of (-)-SPD, dependent upon different experimental conditions, are discussed.

Topics: Alkaloids; Animals; Apomorphine; Berberine; Berberine Alkaloids; Dopamine Antagonists; Dose-Response Relationship, Drug; Electrophysiology; Neurons; Rats; Rats, Inbred Strains; Substantia Nigra

The protective effects of tetrahydroprotoberberines (THPB), viz., l-tetrahydropalmatine (THP), l-stepholidine (SPD), and tetrahydroberberine (THB) on experimental myocardial infarction by ligating the left coronary artery were estimated in rats. The myocardial infarction size (MIS) was determined by nitro-blue tetrazolium technique. THP, SPD, and THB, as well as propranolol, played a remarkable role in diminishing the MIS within 24 h and decreasing the rise of creatine kinase (CK) and aspartate aminotransferase (AST) in the serum within 4 h after the ligation of the coronary artery. Among these drugs, SPD provided the myocardium with the best protective benefit. Systolic and diastolic blood pressures (SBP and DBP) were rapidly lowered after SPD 2.5 mg.kg-1 iv by 39.5% and 48.5%, respectively. The value of the MBP x HR x LVET was concomitantly decreased by 35.1% in the anaesthetized rats. The myocardial contractility and diastolic compliance were not implicated during the experimental regimen. The prophylactic administration of SPD 2.5 mg.kg-1 improved the cardiac hemodynamic alterations caused by ligating the left coronary artery. SPD depressed the elevation of T and LVEDP, and reduction of +dP/dtmax, Vpm, and Vmax besides complete resistance to the reduction of -dP/dtmax and LVSP, underlying the precautions against the damage of the myocardial contractility and diastolic compliance, especially the latter.

Topics: Alkaloids; Animals; Aspartate Aminotransferases; Berberine; Berberine Alkaloids; Creatine Kinase; Female; Hemodynamics; Male; Myocardial Infarction; Rats; Rats, Inbred Strains

The extracellular (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) in rat striatum were measured by in vivo voltammetry to elucidate the effects of 3 tetrahydroprotoberberines on DA neurotransmission. l-tetrahydropalmatine (l-THP, 2 mg.kg-1) or l-stepholidine (l-SPD, 0.5 mg.kg-1) iv increased the striatal DA release by 225% and 233%, respectively; and l-SPD increased the DOPAC level by 70%. Moreover, the enantiomer d-THP (2 mg.kg-1) increased the DA release by 97%, and a large dose of d-THP (20 mg.kg-1) dramatically increased the extracellular DA by 1456% while it slightly elevated the DOPAC level by 123%. These results support the previous ideas that l-SPD and l-THP can block DA receptors and d-THP can deplete neuronal DA.

Topics: 3,4-Dihydroxyphenylacetic Acid; Alkaloids; Animals; Berberine; Berberine Alkaloids; Calcium Channel Blockers; Caudate Nucleus; Corpus Striatum; Dopamine; Male; Microelectrodes; Polarography; Rats; Stereoisomerism

l-Tetrahydropalmatine (l-THP), tetrahydroberberine (THB) and l-stepholidine (l-SPD) are the homologues of tetrahydroproto berberines and have a common antagonistic effect to central dopamine receptors. In the present experiment, the potassium iontophoretic dolorimetry was used to determine the pain threshold of rabbits. Unilateral "Hegu" point (the dorsum of the front paw, between 1st and 2nd metacarpals) and "Waiguan" point (the dorsum of the foreleg, between radius and ulna, 2 cm above the wrist joint) of each rabbit were electrically needled. The effects of iv l-THP 8 mg/kg, THB 16 mg/kg or l-SPD 4 mg/kg on electroacupuncture analgesia were investigated. The experimental results indicated that these 3 agents enhanced the potency of electroacupuncture analgesia and prolonged the duration as well. This investigation gives the evidence that the drug possessing antagonistic effect to central dopamine receptors could be used as a synergist of acupuncture analgesia.

Topics: Acupuncture Analgesia; Alkaloids; Animals; Berberine; Berberine Alkaloids; Electroacupuncture; Female; Male; Pain; Rabbits; Sensory Thresholds

The effects of 12 tetrahydroprotoberberines (THPBs) on D1 and D2 receptors labelled with [3H]DA, [3H]Sch-23390 and [3H]spiperone were evaluated. Their effects on the activity of adenylate cyclase stimulated with DA 40 mumols/L were also assessed. All of the l-THPBs tested behaved as DA receptor antagonists with preferential affinity toward the D1 receptors. Among them, l-stepholidine (l-SPD), a THPB analog with 2 hydroxy groups at the C2 and C10 positions, was the most potent. Its affinity toward D1 receptors was 4-7 times higher than that toward D2 receptors. The results suggest that the hydroxy groups in l-THPBs are very important factors in determining the affinity to DA receptors. Moreover, d-tetrahydropalmatine (d-THP), a dextro-THPB analog, displayed no affinity for the D2 receptor subtype, while its optical isomer, l-THP, was a DA receptor antagonist. This indicates that the levo-optical configuration is necessary for the affinity of THPBs to DA receptors. In addition, l-SPD was 18 times more potent than haloperidol with respect to binding to D1 receptors, but 14 times weaker for D2 receptors. Thus, it is expected that the clinical effects of l-SPD can be distinguished from that of haloperidol.

Topics: Adenylyl Cyclases; Alkaloids; Animals; Berberine; Berberine Alkaloids; Brain; Cattle; Corpus Striatum; Rats; Receptors, Dopamine; Receptors, Dopamine D1; Receptors, Dopamine D2; Stereoisomerism

Topics: Alkaloids; Animals; Berberine; Berberine Alkaloids; Cattle; Molecular Conformation; Quantum Theory; Rats; Receptors, Dopamine; Stereoisomerism; Structure-Activity Relationship

In rats lesioned by unilateral micro-injection of 6-OHDA into substantia nigra, the apomorphine-induced contralateral rotation and the amphetamine-induced ipsilateral rotation were antagonized by THB, l-THP and haloperidol. Scopolamine reversed the antagonistic effect of THB against amphetamine. Thus, THB and l-THP exhibited the DA-receptor antagonistic property which was similar to that of haloperidol. l-SPD (10 mg/kg), however, only antagonized the amphetamine-challenged rotational response, while it could not antagonize, but potentiate, the apomorphine-challenged rotational response. So, l-SPD might be a partial agonistic antagonist of DA-receptors, and its effect was more potent than that of THB and l-THP. l-SPD would be ascertained further in clinic trial. From these results and others, the authors suggest that THPB is a new chemical type of antagonist of brain DA-receptors.

Topics: Alkaloids; Animals; Antipsychotic Agents; Berberine; Berberine Alkaloids; Corpus Striatum; Haloperidol; Rats; Receptors, Dopamine; Scopolamine; Substantia Nigra