Phytochemistry and biological activities of corynanthe alkaloids.

Medicinal plants constitute a source for designing clinically useful drugs targeting diseases through various mechanisms. Plant secondary metabolites can be used as lead compounds of drugs. Corynanthe alkaloids are highly abundant natural bioactive substances of various core structures possessing important properties such as nerve excitation and antimalarial and analgesic effects. In this review, we summarize and review the state-of-the-art corynanthe-type alkaloid research focusing on phytochemistry, pharmacology, and structural chemistry. Approximately 120 articles reporting 231 alkaloids classified into simple corynanthe, yohimbine, oxindole corynanthe, mavacurane, sarpagine, akuammiline, strychnos, and ajmaline-type groups were compiled. Relevant biological properties discussed include antiviral, antibacterial, anti-inflammatory, antimalarial, muscle-relaxant, vasorelaxant, and analgesic activities and activities affecting the main nervous and cardiac systems, as well as NF-κB inhibitory and Na+-glucose cotransporter inhibitory properties. This review provides insights and a reference for future studies, thus paving the way for the discovery of drugs based on corynanthe alkaloids.

Four new corynanthe-type alkaloids from the roots of Alstonia scholaris.

Four new corynanthe-type alkaloids, meloslines C-F (1-4), together with four known ones (5-8) were isolated from the roots of Alstonia scholaris. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis and electronic circular dichroism (ECD) calculation. Compounds 1 and 2 exhibited potent vasorelaxant activity on endothelium-intact renal arteries precontracted with KCl.

Hypertensive Urgency: An Undesirable Complication of a "Male Performance" Herbal Product.

BACKGROUND: Hypertensive urgency is a clinical scenario that may be associated with herbal supplement use and that requires special consideration with regard to emergency department management. CASE REPORT: A 49-year-old man presented to the emergency department with palpitations and severely elevated blood pressure without evidence of end organ dysfunction. Hypertension failed to be controlled with multiple doses of oral clonidine and intravenous labetalol. The patient later admitted to using an herbal supplement containing yohimbine, a selective ⍺2-adrenoreceptor antagonist specifically linked to cases of refractory hypertension. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Between 17-35% of the U.S. adult population may use herbal supplements on a sporadic or regular basis; pharmacologically active agents in herbal supplements may affect both a patient's presentation and response to treatment. Most patients do not mention over-the-counter and herbal products in their medication profile unless specifically asked, and therefore it is important for emergency physicians to be aware of the pharmacologic effects of herbal supplements in the evaluation and treatment of refractory severe hypertension.

Effects of a topical lotion containing aminophylline, caffeine, yohimbe, l-carnitine, and gotu kola on thigh circumference, skinfold thickness, and fat mass in sedentary females.

BACKGROUND AND OBJECTIVE: Topical aminophylline, caffeine, yohimbe, l-carnitine, and gotu kola (Centella asiatica) may aid in reducing body fat. Lipoxyderm™ contains these ingredients and was used to test if fat loss of the thigh, in conjunction with a low intensity exercise program and restricted calorie intake, was enhanced via the topical application of this lotion. METHODS: This was a double-blind, placebo-controlled, within-group study that investigated the effects of Lipoxyderm™ on thigh fat mass, circumference, and skinfold thickness. Seven participants underwent pre/post-exercise testing for weight, bilateral thigh circumference/skinfold thickness, and body composition/thigh fat mass assessment via dual-energy X-ray absorptiometry. Participants followed a hypocaloric diet, walked 150 minutes/wk, and were randomly assigned to apply a placebo to one leg and Lipoxyderm™ to their other leg for 28 days. Separate two-way mixed factorial repeated measures ANOVAs were used to compare the effects of Lipoxyderm™ to the placebo on thigh circumference, skinfold thickness, and fat mass. RESULTS: A significant time x group interaction was found for thigh circumference (F1,6  = 18.2, P = 0.005), skinfold thickness (F1,6  = 14.6, P = 0.009), and fat mass (F1,6  = 37.1, P = 0.001). CONCLUSIONS: A twice-daily topical application of Lipoxyderm™ for 28 days compared to a placebo combined with a walking program and a restricted caloric intake is more effective at reducing thigh circumference (1.2 vs 0.8 cm), thigh skinfold thickness (3.7 vs 2.0 mm), and thigh fat mass (100.0 g vs 57.3 g).

Heart Toxicity Related to Herbs and Dietary Supplements: Online Table of Case Reports. Part 4 of 5.

BACKGROUND: The purpose of this review was to create an online research summary table of heart toxicity case reports related to dietary supplements (DS; includes herbs). METHODS: Documented PubMed case reports of DS appearing to contribute to heart-related problems were used to create a "Toxic Table" that summarized the research (1966 to April, 2016, and cross-referencing). Keywords included "herb," "dietary supplement," and cardiac terms. Case reports were excluded if they were herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, mushrooms, poisonous plants, self-harm (e.g. suicide), excess dose (except vitamins/minerals), drugs or illegal drugs, drug-herbal interactions, and confounders of drugs or diseases. The spectrum of heart toxicities included hypertension, hypotension, hypokalemia, bradycardia, tachycardia, arrhythmia, ventricular fibrillation, heart attack, cardiac arrest, heart failure, and death. RESULTS: Heart related problems were associated with approximately seven herbs: Four traditional Chinese medicine herbs - Don quai (Angelica sinensis), Jin bu huan (Lycopodium serratum), Thundergod vine or lei gong teng (Tripterygium wilfordii Hook F), and Ting kung teng (Erycibe henryi prain); one an Ayruvedic herb - Aswagandha, (Withania somnifera); and two North American herbs - blue cohosh (Caulophyllum thalictroides), and Yohimbe (Pausinystalia johimbe). Aconitum and Ephedra species are no longer sold in the United States. The DS included, but are not limited to five DS - bitter orange, caffeine, certain energy drinks, nitric oxide products, and a calming product. Six additional DS are no longer sold. Licorice was the food related to heart problems. CONCLUSION: The online "Toxic Table" forewarns clinicians, consumers and the DS industry by listing DS with case reports related to heart toxicity. It may also contribute to Phase IV post marketing surveillance to diminish adverse events that Government officials use to regulate DS.

Dietary supplement for energy and reduced appetite containing the ß-agonist isopropyloctopamine leads to heart problems and hospitalisations.

In 2013 the Dutch authorities issued a warning against a dietary supplement that was linked to 11 reported adverse reactions, including heart problems and in one case even a cardiac arrest. In the UK a 20-year-old woman, said to have overdosed on this supplement, died. Since according to the label the product was a herbal mixture, initial LC-MS/MS analysis focused on the detection of plant toxins. Yohimbe alkaloids, which are not allowed to be present in herbal preparations according to Dutch legislation, were found at relatively high levels (400-900 mg kg(-1)). However, their presence did not explain the adverse health effects reported. Based on these effects the supplement was screened for the presence of a ß-agonist, using three different biosensor assays, i.e. the validated competitive radioligand ß2-adrenergic receptor binding assay, a validated ß-agonists ELISA and a newly developed multiplex microsphere (bead)-based ß-agonist assay with imaging detection (MAGPIX(®)). The high responses obtained in these three biosensors suggested strongly the presence of a ß-agonist. Inspection of the label indicated the presence of N-isopropyloctopamine. A pure standard of this compound was bought and shown to have a strong activity in the three biosensor assays. Analysis by LC-full-scan high-resolution MS confirmed the presence of this 'unknown known' ß3-agonist N-isopropyloctopamine, reported to lead to heart problems at high doses. A confirmatory quantitative analysis revealed that one dose of the preparation resulted in an intake of 40-60 mg, which is within the therapeutic range of this compound. The case shows the strength of combining bioassays with chemical analytical techniques for identification of illegal pharmacologically active substances in food supplements.

Pharmaceutical quantities of yohimbine found in dietary supplements in the USA.

In the USA, botanical dietary supplements are presumed to be safe, but this is not necessarily always the case. Extracts of the evergreen tree yohimbe, Pausinystalia johimbe, though banned in many countries, are sold in hundreds of dietary supplements in the USA. We analyzed 49 brands of supplements labelled as containing yohimbe or yohimbine available for sale from seven major retailers in the USA. Supplements were analyzed using ultra high-performance liquid chromatography coupled to photodiode and quadrupole time-of-flight mass spectrometry detectors for quantity of three alkaloids found in P. johimbe (yohimbine, rauwolscine, and corynanthine). The alkaloids were confirmed on the basis of retention time, ultraviolet spectra, and mass spectra against reference standards. The quantity of the most active alkaloid, yohimbine, per recommended serving ranged from none detected to 12.1 mg. Thirty-nine percent of the supplements (19/49) did not contain rauwolscine and corynanthine suggesting that the yohimbine was either from highly processed plant extract or synthetic in origin. Only 11 supplement brands (22%, 11/49) listed a specific quantity of yohimbine on the label. Most of these were inaccurately labelled (actual content ranged from 23% to 147% of the content on the label). Eighteen percent (9/49) of the supplements' labels did not provide any information about yohimbine's adverse effects. Of the 49 yohimbine supplement brands sold at seven major retail chains in the USA, only 4.1% (2/49) provided consumers with both accurate information about the quantity of yohimbine as well as information about yohimbine's known adverse effects. Copyright © 2015 John Wiley & Sons, Ltd.

Determination of Yohimbine in Yohimbe Bark and Related Dietary Supplements Using UHPLC-UV/MS: Single-Laboratory Validation.

A single-laboratory validation was performed on a practical ultra-HPLC (UHPLC)-diode array detector (DAD)/tandem MS method for determination of yohimbine in yohimbe barks and related dietary supplements. Good separation was achieved using a Waters Acquity ethylene bridged hybrid C18 column with gradient elution using 0.1% (v/v) aqueous ammonium hydroxide and 0.1% ammonium hydroxide in methanol as the mobile phases. The method can separate corynanthine from yohimbine in yohimbe bark extract, which is critical for accurate quantitation of yohimbine in yohimbe bark and related dietary supplements. Accuracy of the method was demonstrated using standard addition methods. Both intraday and interday precisions of the method were good. The method can be used without MS since yohimbine concentration in yohimbe barks and related dietary supplements are usually high enough for DAD detection, which can make it an easy and economical method for routine analysis of yohimbe barks and related dietary supplements. On the other hand, the method can be used with MS if desired for more challenging work such as biological and/or clinical studies.

Cytotoxic vobasine, tacaman, and corynanthe-tryptamine bisindole alkaloids from Tabernaemontana and structure revision of tronoharine.

Seven new indole alkaloids (1-7) comprising four vobasine, two tacaman, and one corynanthe-tryptamine bisindole alkaloid were isolated from the stem-bark extract of a Malayan Tabernaemontana. Two of the new vobasine alkaloids (1, 3), as well as 16-epivobasine (15) and 16-epivobasenal (17), showed appreciable cytotoxicity toward KB cells (IC50 ca. 5 µg/mL). The structure of the known Tabernaemontana alkaloid tronoharine (8) was revised based on newly acquired NMR data, as well as X-ray diffraction analysis.

Microscopic and UPLC-UV-MS analyses of authentic and commercial yohimbe (Pausinystalia johimbe) bark samples.

Yohimbine is the major alkaloid found in the stem bark of yohimbe, Pausinystalia johimbe (Rubiaceae), an evergreen tree native to Africa. The objectives of the current study were to provide a detailed anatomy of yohimbe bark, as well as to determine the quantity of yohimbine in the raw yohimbe products sold online. Twelve commercial raw materials of yohimbe were analyzed by microscopic and ultra performance liquid chromatography-UV-MS methods. The study revealed that three samples were probably adulterated and four other samples contained various levels of impurities. Yohimbine was not detected in one sample, whereas its presence in other samples was found to be in the range 0.1-0.91%. The present work also provides a detailed anatomy of the stem bark of yohimbe, with light and scanning electron microscopy images, for proper identification and authentication.

Chromatographic fingerprint analysis of yohimbe bark and related dietary supplements using UHPLC/UV/MS.

A practical ultra high-performance liquid chromatography (UHPLC) method was developed for fingerprint analysis of and determination of yohimbine in yohimbe barks and related dietary supplements. Good separation was achieved using a Waters Acquity BEH C(18) column with gradient elution using 0.1% (v/v) aqueous ammonium hydroxide and 0.1% ammonium hydroxide in methanol as the mobile phases. The study is the first reported chromatographic method that separates corynanthine from yohimbine in yohimbe bark extract. The chromatographic fingerprint analysis was applied to the analysis of 18 yohimbe commercial dietary supplement samples. Quantitation of yohimbine, the traditional method for analysis of yohimbe barks, were also performed to evaluate the results of the fingerprint analysis. Wide variability was observed in fingerprints and yohimbine content among yohimbe dietary supplement samples. For most of the dietary supplements, the yohimbine content was not consistent with the label claims.

Palliative effect of Pausinystallia macroceras on testicular ischemic reperfusion injury in Wistar rats: a histological study / Efecto paliativo de Pausinystallia macroceras sobre la lesión testicular por isquemia-reperfusión en ratas Wistar: un estudio histológico

Testicular torsion is a disorder involving the scrotum that results in a compromise of its blood supply. The aim was to investigate the effect of Pausinystallia macroceras (PM) on testicular histology following torsion-detortion at different time intervals ranging from 1 to 4 hours 65 mature male Wister rats allotted randomly into seven groups (A to G; E& F further divided into 4-subgroups). Each group/subgroup comprised 5 rats. Testis maintained in the torted position (T) for 1, 2, 3 and 4 hours in Groups A (AT1+PM), B (BT2+PM), C (CT3+PM) and D (DT4+PM). Group E subgroups (E1+PM, E2+PM, E3+PM, E4+PM -) were sham operated, without torsion served as the sham control. Group F subgroups (F1T1, F2T2, F3T3 and F4T4) were torted as in A. All animals (except groups F & G) treated with PM extract (0.1 g/kg.b.w/day) for 56 days. Group G rats (normal control). Testes processed for histological studies. In AT1+PM showed preserved seminiferous tubules. BT2+PM, revealed varying number of necrosed and apoptotic seminiferous tubules. Group CT3+PM rats were similar to BT2+PM although with a slightly higher proportion of seminiferous tubules had undergone necrosis. In DT4+PM, sections showed few viable spermatozoa within the seminiferous tubules. When compared to the torted group F; showed extensive areas of seminiferous tubular necrosis (F3T3) as well as damage to the interstitium; while in F4T4 there were no viable testicular tissues seen. In conclusion, PM significantly prevented the cellular changes and cell death observed especially in group AT1+PM and BT2+PM.

La torsión testicular es un trastorno que involucra el escroto resultando en un compromiso del suministro sanguíneo. El objetivo fue investigar el efecto de Pausinystallia macroceras (PM) en la histología testicular tras torsión-detorsión a intervalos de tiempo diferentes que van desde 1 a 4 horas en 65 ratas macho Wistar maduras, asignando aleatoriamente en siete grupos (desde A a G, mientras que E y F se dividieron en 4 subgrupos). Cada grupo/subgrupo estuvo compuesto por 5 ratas. Los testículos se mantuvieron en posición torsionada (T) durante 1, 2, 3 y 4 horas en los grupos A (AT1 + PM), B (BT2 + PM), C (CT3 + PM) y D (DT4 + PM). El grupo E, subgrupos (E1 + PM, E2 + PM + PM E3, E4 + PM) fueron operados por modelo sham sin torsión, que sirvió de control. El grupo F, subgrupos (F1T1, F2T2, F3T3 y F4T4) fueron torsionados como en A. Todos los animales (excepto los grupos F y G) fueron tratados con extracto de AM (0,1 g/kg peso corporal/día) durante 56 días. El grupo G fueron ratas control (control normal). Los testículos fueron procesados para el estudio histológico. En AT1 + PM se observó preservación de los túbulos seminíferos. BT2 + PM, reveló un número variable de túbulos seminíferos con necrosis y apoptosis. El grupo de ratas CT3 + PM fue similar a BT2 + PM, aunque un porcentaje ligeramente superior de los túbulos seminíferos mostraron necrosis. En DT4 + PM, los cortes mostraron pocos espermatozoides viables dentro de los túbulos seminíferos. En comparación con el grupo F torsionado mostró extensas áreas de necrosis tubular (F3T3), así como daños en el intersticio; mientras que en F4T4 no hubo tejido testicular viable. En conclusión, PM previno significativamente cambios celulares y la muerte celular observada, especialmente en el grupo AT1 + PM y BT2 + PM.

Profiling the indole alkaloids in yohimbe bark with ultra-performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry.

An ultra-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry (UPLC/IM-QTOF-MS) method was developed for profiling the indole alkaloids in yohimbe bark. Many indole alkaloids with the yohimbine or ajmalicine core structure, plus methylated, oxidized and reduced species, were characterized. Common fragments and mass differences are described. It was shown that the use of IMS could provide another molecular descriptor, i.e. molecular shape by rotationally averaged collision cross-section; this is of great value for identification of constituents when reference materials are usually not available. Using the combination of high resolution (~40000) accurate mass measurement with time-aligned parallel (TAP) fragmentation, MS(E) (where E represents collision energy), ion mobility mass spectrometry (IMS) and UPLC chromatography, a total 55 indole alkaloids were characterized and a few new indole alkaloids are reported for the first time.

Refractory priapism associated with ingestion of yohimbe extract.

Extracts of the bark of the central African tree Pausinystalia yohimbe contain yohimbine, an indole alkaloid, which is used to treat erectile dysfunction. The reported side effects of over-the-counter preparations of yohimbine include gastrointestinal upset, anxiety, increased blood pressure, headache, agitation, rash, tachycardia, and frequent urination. In this report, we describe a severe case of intractable priapism associated with the ingestion of yohimbe extract. Management required insertion of a proximal cavernosal spongiosum shunt (Quackles shunt) in the operating room.

Qualitative and quantitative determination of yohimbine in authentic yohimbe bark and in commercial aphrodisiacs by HPLC-UV-API/ MS methods.

The development and validation of a rapid qualitative and quantitative method based on an HPLC-UV-MS technique with atmospheric pressure chemical ionisation and electrospray ionisation for the analysis of yohimbine in a number of commercial aphrodisiac products is reported. HPLC with multiple-stage mass spectrometry experiments allowed the identification of the target compound and increased the selectivity of complex analyses such as those involved with multi-botanical preparations. The precision and the robustness of the method were improved by the use of two internal standards: codeine for UV detection and deuterium-labelled yohimbine for MS detection. Twenty commercial aphrodisiac preparations were analysed and the amount of yohimbine measured and expressed as the maximal dose per day suggested on product labels ranged from 1.32 to 23.16 mg.

Endothelin-like action of Pausinystalia yohimbe aqueous extract on vascular and renal regional hemodynamics in Sprague Dawley rats.

The bark of the African tree Pausinystalia yohimbe has been used as a food additive with aphrodisiac and penile erection enhancing properties. The effect of an aqueous extract of P. yohimbe (CCD-X) on renal circulation was assessed in order to test the hypothesis that it possesses additional effects on nitric oxide production and/or endothelin-1 (ET-1)-like actions. In vivo studies with CCD-X in Sprague Dawley rats demonstrated a dose-dependent (1-1000 ng/kg) increase in mean blood pressure (p < 0.001) and an increase in medullary blood flow (MBF) (p < 0.001). Both the pressor action and renal medullary vasodilation were blocked by endothelinA (ETA) receptor antagonist BMS182874 and endothelinB (ETB) receptor antagonist BQ788 in combination. L-Nomega-nitro-l-arginine methyl ester (L-NAME; 10 mg/kg) also inhibited the increase in MBF induced by CCD-X. In vitro studies in isolated perfused kidney and in pressurized renal microvessels confirmed the dose-dependent vasoconstrictor action of this extract. ETA receptor antagonist BQ610 and ETB receptor antagonist BQ788 separately and significantly attenuated the renal vasoconstrictor actions of the extract (p < 0.001 ANOVA). These preliminary observations indicate that, in addition to the alpha-adrenergic antagonist actions that characterize yohimbine, CCD-X possesses endothelin-like actions and affects nitric oxide (NO) production in renal circulation. These findings suggest a strong possibility of post-receptor cross-talk between alpha2-adrenoceptors and endothelin, as well as a direct effect of alpha2-adrenoceptors on renal NO production.