RESUMEN
Amygdalin, despite possessing anticancerous properties, has been viewed as a controversial choice due to the presence of the cyanide group. Here, we synthesise and investigate the potential of alginate-chitosan nanoparticles (ACNPs) as drug delivery agents for amygdalin encapsulation and its delivery to cancer cells. Amygdalin loaded ACNPs were made with both anionic and cationic outer layer to further investigate charge dependency on drug delivery and cytotoxicity. ACNPs encapsulating amygdalin were monodisperse, colloidally stable with ~90% drug encapsulation efficiency and were entirely made from natural materials. The nanoparticles exhibited sustained drug release for a duration of 10 h and significant swelling rates in neutral and slightly acidic environments. The ACNPs successfully adhered to porcine mucin type II when assessed for its mucoadhesion and shown to transmigrate with an average velocity of 1.68 µm/s in uncoated channels, under biomimicked flow conditions. To investigate charge dependency on drug delivery and cytotoxicity, amygdalin loaded ACNPs were made with both anionic and cationic outer layer and assessed. ACNPs demonstrated greater yet sustained anti-cancerous effect on H1299 cell lines in a dose-dependent manner than free amygdalin suggesting greater cellular uptake of the former. In conclusion, biocompatible and biodegradable alginate-chitosan nanoparticles can be used as an effective drug delivery system for sustained and controlled amygdalin release with its improved cytotoxic effect on cancerous cells while protecting normal cells and tissues.
Asunto(s)
Amigdalina , Antineoplásicos , Quitosano , Portadores de Fármacos , Neoplasias Pulmonares , Ensayo de Materiales , Nanopartículas , Amigdalina/química , Amigdalina/farmacocinética , Amigdalina/farmacología , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacología , Línea Celular Tumoral , Quitosano/química , Quitosano/farmacocinética , Quitosano/farmacología , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Nanopartículas/química , Nanopartículas/uso terapéuticoRESUMEN
Amygdalin, named as 'laetrile' and 'vitamin B-17' was initially supposed to be a safe drug for cancer treatment and was recognized by followers of natural medicine since it has been considered to be hydrolyzed only in cancer cells releasing toxic hydrogen cyanide (HCN), and thus destroying them. Unfortunately, current studies have shown that HCN is also released in normal cells, therefore it may not be safe for human organism. However, there have still been research works conducted on anti-cancer properties of this compound. In vitro experiments have shown induction of apoptosis by amygdalin as a result of increased expression of Bax protein and caspase-3 and reduced expression of antiapoptotic BcL-2protein. Amygdalin has also been shown to inhibit the adhesion of breast cancer cells, lung cancer cells and bladder cancer cells by decreased expression of integrin's, reduction of catenin levels and inhibition of the Akt-mTOR pathway, which may consequently lead to inhibition of metastases of cancer cells. It has also been revealed that amygdalin in renal cancer cells increased expression of p19 protein resulting in inhibition of cell transfer from G1-phase to S-phase, and thus inhibited cell proliferation. Other studies have indicated that amygdalin inhibits NF-kß and NLRP3 signaling pathways, and consequently has anti-inflammatory effect due to reducing the expression of proinflammatory cytokines such as pro-IL-1ß. Moreover, the effect of amygdalin on TGFß/CTGF pathway, anti-fibrous activity and expression of follistatin resulting in activation of muscle cells growth has been reported. This compound might be applicable in the treatment of various cancer cell types.
Asunto(s)
Amigdalina/uso terapéutico , Fase G1/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Proteínas de Neoplasias/biosíntesis , Neoplasias , Fase S/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Amigdalina/farmacocinética , Animales , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patologíaRESUMEN
BACKGROUND: It is well-known that the public still have been facing on a severe issue about the inconsistency of quality and therapeutic efficacy of traditional medicines. Recently, Professor Chang-Xiao Liu has created a new promising concept for identifying relevant quality-markers (Q-marker) from herbs, their formulas and manufacturing products. Therefore, building up a new approach is necessary for us to bridge over quality to efficacy of pharmaceutical products. STUDY DESIGN: In this paper, five candidate Q-markers, astragaloside IV, paeonflorin, amygdalin, tetramethylpyrazine, ferulic acid in Buyanghuanwu injection (BYHWI) had been designed to carry out in rat by using single and polypharmacokinetic models for total quanta to ascertain adequate Q-marker. METHODS: The Q-marker transitivity in vivo was studied with polypharmacokinetic model and its similarity approach, which were modeled with TQSM principle. The Q-marker was ascertained with transitive similarity and bioavailability in polypharmacokinetics. Their concentrations in plasma sample of white rat were determined by RP-HPLC. Data analyses were used by the DAS software for singles and myself-written-program with EXCEL for multiples. RESULTS: In BYHWI, five candidate Q-marker pharmacokinetic profiles were singly fixed to two compartmental models in rat using classical compartmental analysis, but there were tremendous differences among which the candidate parameters were fluctuated from nearly 3552 folds to equivalency. The theoretical value of TQSM polypharmacokinetic parameters such as AUCT, MRTT, VRTT, CLT, VT over the mixure of five drugs were 110.8⯱â¯51.91â¯mg min ml-1, 176.0⯱â¯36.5â¯min, 39,921⯱â¯4311 min2, 0.3116⯱â¯0.02347â¯ml min-1 kg-1, 54.83⯱â¯7.683â¯ml kg-1 respectively. The TQSM polypharmacokinetic parameters in astragaloside â £ ordered by AUCT, MRTT, VRTT, CLT, VT were 110.8⯱â¯51.91â¯mg min ml-1, 176.0⯱â¯36.5â¯min, 39,921⯱â¯4311 min2, 0.3116⯱â¯0.02347â¯ml min-1 kg-1, 54.83⯱â¯7.683â¯ml kg-1, respectively, which were closed to the theoretical values. TQSM similarity versus astragaloside â £ was 0.9661. CONCLUSION: The results represented that the optimum Q-marker in BYHWI is astragaloside â £, whose transitivity in vivo similarity was close to the behavior of polypharmacokinetics with maximum bioavailability to the total quanta. It is feasible for Q-marker in CMMs to screen on the comparison of single pharmacokinetic behavior and bioavailability to the total quanta.
Asunto(s)
Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacocinética , Amigdalina/sangre , Amigdalina/farmacocinética , Animales , Disponibilidad Biológica , Biomarcadores/sangre , Cromatografía Líquida de Alta Presión/métodos , Ácidos Cumáricos/sangre , Ácidos Cumáricos/farmacocinética , Medicamentos Herbarios Chinos/administración & dosificación , Glucósidos/sangre , Glucósidos/farmacocinética , Inyecciones , Monoterpenos/sangre , Monoterpenos/farmacocinética , Pirazinas/sangre , Pirazinas/farmacocinética , Ratas Wistar , Saponinas/sangre , Saponinas/farmacocinética , Triterpenos/sangre , Triterpenos/farmacocinéticaRESUMEN
BACKGROUND AND OBJECTIVES: Ephedra alkaloids, including ephedrine (EP), pseudoephedrine (PEP) and methylephedrine (MEP), are sympathomimetic compounds with known toxicities but many Ephedra (Ephedrae herba) preparations, such as Ephedra decoction, have been clinically applied for centuries. In order to explore the possible detoxification mechanism of Ephedra alkaloids, four representative compounds in Ephedra decoction (cinnamic acid, amygdalin, glycyrrhizic acid and liquiritin) were studied for their pharmacokinetic effects on Ephedra alkaloids in Sprague-Dawley rats. METHODS: Animals were randomly divided into six groups, with six rats in each. Rats were treated orally with EP-PEP-MEP (20 mg/kg EP + 20 mg/kg PEP + 20 mg/kg MEP) and different combinations of cinnamic acid (3.03 mg/kg), amygdalin (56.97 mg/kg), glycyrrhizic acid (12.42 mg/kg), liquiritin (3.79 mg/kg) with EP-PEP-MEP, and 20 mg/kg EP + 20 mg/kg PEP + 20 mg/kg MEP + 3.03 mg/kg cinnamic acid + 56.97 mg/kg amygdalin + 12.42 mg/kg glycyrrhizic acid + 3.79 mg/kg liquiritin. Blood samples (0.5 mL) were taken from the orbital sinus venous plexus into heparinized tubes at 5, 10, 20, 30, 45, 60, 90, 120, 180, 240, 300 and 360 min (6 rats per time point in each group) following single administration. The concentrations of Ephedra alkaloids in rat plasma were determined using a validated high performance liquid chromatography method. RESULTS: Area under the concentration-time curve from 0 to 360 min (AUC0-t ) of EP, PEP and MEP were 666.99, 650.76 and 632.37 µg·min/mL, respectively. Maximum plasma concentration (C max) of EP, PEP and MEP were 4.15, 4.08 and 3.59 µg/mL, respectively. Mean residence time (MRT) of EP, PEP and MEP were 197.00, 173.97 and 183.87 min, respectively, when the rats were treated with EP-PEP-MEP. Cinnamic acid increased the AUC0-t of EP while decreased C max of EP, amygdalin and glycyrrhizic acid increased C max and AUC0-t of EP and PEP, while liquiritin decreased AUC0-t of EP and PEP. The four representative compounds reduced MRT of EP, PEP and MEP, four compounds decreased AUC0-t of MEP. The EP-PEP-MEP + cinnamic acid + amygdalin + glycyrrhizic acid + liquiritin group increased AUC0-t of EP while decreased MRT of EP, increased MRT of PEP while decreased AUC0-t of PEP. The EP-PEP-MEP + cinnamic acid + amygdalin + glycyrrhizic acid + liquiritin group decreased MRT, AUC0-t and C max of MEP. CONCLUSIONS: Significant changes in pharmacokinetic parameters of EP, PEP and MEP were observed after oral administration with different combinations. The pharmacokinetic results reported here might provide reference for clinical usage of Ephedra alkaloids.
Asunto(s)
Alcaloides/farmacocinética , Amigdalina/farmacocinética , Cinamatos/farmacocinética , Ephedra/química , Flavanonas/farmacocinética , Glucósidos/farmacocinética , Ácido Glicirrínico/farmacocinética , Extractos Vegetales/farmacocinética , Animales , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos , Masculino , Ratas , Ratas Sprague-Dawley , Espectrometría de Masas en Tándem/métodosRESUMEN
Guizhi Fuling capsule (GZFL), a traditional Chinese medicine formulation, is widely used in China to relieve pain from dysmenorrhea and is now in a Phase II clinical trial in the USA. Due to the low exposure of the five main medicative ingredients (amygdalin, cinnamic acid, gallic acid, paeoniflorin and paeonol) of GZFL in human, a strategy was built to qualitatively and quantitatively identify the possible metabolites of GZFL and to describe the pharmacokinetic profiles of GZFL in human. In this strategy, LC-Q-TOF/MS was used to identify and structurally elucidate the possible metabolites of GZFL in vivo; and a time-based metabolite-confirming step (TBMCs) was used to confirm uncertain metabolites. The simultaneously quantitation results by LC-MS/MS showed low exposure of the five medicative ingredients. According to the strategy we built, a total of 36 metabolites were found and structurally elucidated. The simultaneously semi-quantitative analysis by LC-MS/MS showed that obvious time-concentration curves could be established for 12 of the metabolites, and most of them showed a relatively higher exposure. This study provides a better understanding of the metabolic processes of GZFL in human.
Asunto(s)
Medicamentos Herbarios Chinos/farmacocinética , Acetofenonas/administración & dosificación , Acetofenonas/química , Acetofenonas/farmacocinética , Amigdalina/administración & dosificación , Amigdalina/química , Amigdalina/farmacocinética , Cápsulas , Cromatografía Líquida de Alta Presión/métodos , Cinamatos/administración & dosificación , Cinamatos/química , Cinamatos/farmacocinética , Medicamentos Herbarios Chinos/administración & dosificación , Medicamentos Herbarios Chinos/química , Femenino , Ácido Gálico/administración & dosificación , Ácido Gálico/química , Ácido Gálico/farmacocinética , Glucósidos/administración & dosificación , Glucósidos/química , Glucósidos/farmacocinética , Voluntarios Sanos , Humanos , Masculino , Estructura Molecular , Monoterpenos/administración & dosificación , Monoterpenos/química , Monoterpenos/farmacocinética , Espectrometría de Masas en Tándem/métodosRESUMEN
OBJECTIVE: To analyze the transdermal profile of pseudoephedrine and amygdalin in the Traditional Chinese Medicine majiepingchuan in rat skin and to reveal their interaction. METHODS: A Franz diffusion cell was used in vitro to evaluate the transdermal parameters of cumulative transdermal flux (Q(tot)), cumulative transmission (T(tot)), and mean penetration rate (Kp) of pseudoephedrine and amygdalin in majiepingchuan. Linear regression analyses of Q(tot) over time of pseudoephedrine vs amygdalin and their ratios was adopted for correlation evaluation. RESULTS: At 1, 2, 4, 6, and 8 h, the Q(tot), T(tot) and Kp of pseudoephedrine showed a good correlation with that of amygdalin. CONCLUSION: There was a small difference in the ratios of Q(tot), T(tot) and Kp between pseudoephedrine and amygdalin, and a correlation between them.
Asunto(s)
Amigdalina/farmacocinética , Medicamentos Herbarios Chinos/farmacocinética , Seudoefedrina/farmacocinética , Administración Cutánea , Amigdalina/administración & dosificación , Animales , Medicamentos Herbarios Chinos/administración & dosificación , Masculino , Seudoefedrina/administración & dosificación , Ratas , Ratas Sprague-Dawley , Piel/química , Piel/metabolismoRESUMEN
PURPOSE: Huoxue-Tongluo lyophilized powder for injection (HTLPI), a traditional Chinese medicine preparation, is a compound of Persicae semen and Paeoniae Radix Rubra that is used mainly for treating blood-stasis obstruction syndrome in the acute stage of cerebral ischemic stroke. Amygdalin (AD) and paeoniflorin (PF) are 2 typical bioactive components in HTLPI and were selected as indicators for this pharmacokinetic study of HTLPI. The objective of this study was to investigate the safety profile, tolerability, and pharmacokinetic properties of AD and PF after single and multiple intravenous infusions of HTLPI in healthy Chinese volunteers. METHODS: Twenty-one healthy Chinese subjects were recruited for this open-label, single ascending-dose (3, 6, and 9 g) and multiple-dose (6 g, once daily) study. Safety profile was assessed by adverse events and physical examination throughout the study. Serial plasma and urine samples were analyzed by HPLC-MS/MS. Pharmacokinetic parameters of AD and PF were calculated using noncompartmental analysis. FINDINGS: In the single-dose phase of the study, the mean maximum plasma concentration and the mean area under the plasma concentration-time curve of AD and PF increased proportionally with each dose escalation. In the multiple-dose phase, the steady state was achieved by day 4 after multiple-dose administration of 6 g HTLPI. Mean pharmacokinetic parameters achieved on day 1 were similar to those on day 7. No significant accumulation was observed after repeat doses of 6 g HTLPI. Approximately 79.6% of the administered AD and 48.4% of the administered PF were excreted unchanged in urine within 24 hours. No serious adverse events were observed during the entire study. IMPLICATIONS: The pharmacokinetic properties of AD and PF were linear after a single intravenous infusion of HTLPI in the dose range of 3-9 g. No systemic accumulation was observed with repeat doses of HTLPI. Sex had no significant effect on the pharmacokinetic properties of AD and PF. Intravenous infusion of HTLPI was well tolerated in healthy Chinese subjects.
Asunto(s)
Amigdalina/administración & dosificación , Glucósidos/administración & dosificación , Monoterpenos/administración & dosificación , Adulto , Amigdalina/efectos adversos , Amigdalina/farmacocinética , Pueblo Asiatico , Cromatografía Líquida de Alta Presión , Medicamentos Herbarios Chinos/administración & dosificación , Femenino , Glucósidos/efectos adversos , Glucósidos/farmacocinética , Humanos , Infusiones Intravenosas , Masculino , Monoterpenos/efectos adversos , Monoterpenos/farmacocinética , Polvos , Espectrometría de Masas en Tándem , Adulto JovenRESUMEN
The Mahuang-Xingren herb-pair (MX), the combination of Herba Ephedrae (Mahuang in Chinese) and Semen Armeniacae Amarum (Xingren in Chinese), is a classical combination used in traditional Chinese Medicine to treat asthma and bronchitis. A simple and reliable ultra-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously quantify and compare the pharmacokinetics of 5 ephedra alkaloids and epimers of amygdalin and prunasin in rat plasma after oral administration of Mahuang, Xingren, and MX aqueous extracts. Samples were pretreated by a single-step protein precipitation with acetonitrile, and diphenhydramine hydrochloride and puerarin were used as internal standards. Pharmacokinetic parameters were investigated using DAS 3.2.2 (Mathematical Pharmacology Professional Committee of China, Shanghai, China). The validated method demonstrated adequate sensitivity, selectivity, and process efficiency for the bioanalysis of 8 compounds, including 3 pairs of epimers. MX administration improved the bioavailability of amygdalin and prunasin. Furthermore, MX facilitated intake of lower doses of ephedra alkaloids and increased elimination rates in comparison with Mahuang alone. These results illustrate the rationale behind the preferred use of the combination of Mahuang and Xingren. To our knowledge, this is the first report of stereo-selective metabolism of amygdalin. Further, the metabolic mechanism underlying this phenomenon merits future research attention.
Asunto(s)
Asteraceae/química , Medicamentos Herbarios Chinos/análisis , Medicamentos Herbarios Chinos/farmacocinética , Ephedra/química , Amigdalina/análisis , Amigdalina/farmacocinética , Animales , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Masculino , Nitrilos/análisis , Nitrilos/farmacocinética , Control de Calidad , Ratas , Ratas Sprague-Dawley , Estándares de Referencia , Reproducibilidad de los Resultados , Estereoisomerismo , Espectrometría de Masas en TándemRESUMEN
A simple and sensitive HPLC-MS/MS method was developed and fully validated for the simultaneous determination of amygdalin (AD) and paeoniflorin (PF) in human plasma. For both analytes, the method exhibited high sensitivity (LLOQs of 0.6ng/mL) by selecting the ammonium adduct ions ([M+NH4](+)) as the precursor ions and good linearity over the concentration range of 0.6-2000ng/mL with the correlation coefficients>0.9972. The intra- and inter-day precision was lower than 10% in relation to relative standard deviation, while accuracy was within ±2.3% in terms of relative error for both analytes. The developed method was successfully applied to a pilot pharmacokinetic study of AD and PF in healthy volunteers after intravenous infusion administration of Huoxue-Tongluo lyophilized powder for injection.
Asunto(s)
Amigdalina/sangre , Amigdalina/química , Cromatografía Liquida/métodos , Glucósidos/sangre , Glucósidos/química , Monoterpenos/sangre , Monoterpenos/química , Espectrometría de Masas en Tándem/métodos , Amigdalina/farmacocinética , Medicamentos Herbarios Chinos/química , Glucósidos/farmacocinética , Humanos , Monoterpenos/farmacocinética , Proyectos PilotoRESUMEN
A sensitive and specific liquid chromatography-tandem mass spectrometric (LC-MS-MS) method was developed for the determination and pharmacokinetics of amygdalin in rats. Rat plasma pretreated by solid-phase extraction was analyzed by LC-MS-MS with negative electrospray ionization in the multiple reaction monitoring mode. Amygdalin and geniposide [the internal standard (IS)] were separated on a C18 column eluted with a mobile phase of methanol and water (85:15; v/v) at a flow rate of 0.25 mL/min in a run time of 3.0 min. The precursor to product ion transitions were monitored at m/z 457.2 â 279.1 for amygdalin and m/z 387.1 â 224.9 for the IS. The calibration curve of amygdalin showed good linearity over a concentration range of 10-2,000 ng/mL. The limit of quantification was 10 ng/mL. Intra-day and inter-day precisions and accuracy (percent relative standard deviation) were both within 10%. The method was fully validated for its selectivity, sensitivity, matrix effect, recovery and stability. This accurate and specific assay produced a useful LC-MS-MS method, which was successfully applied to pharmacokinetic studies after the oral administration of amygdalin to rats.
Asunto(s)
Amigdalina/sangre , Amigdalina/farmacocinética , Cromatografía Liquida/métodos , Espectrometría de Masas en Tándem/métodos , Animales , Masculino , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los ResultadosRESUMEN
Psoriasis is one of the most prevalent immune-mediated illness worldwide. The disease can still only be managed rather than cured, so treatments are aimed at clearing skin lesions and preventing their recurrence. Several treatments are available depending on the extent of the psoriatic lesion. Among the topical treatments corticostereoids, vitamin D3 analogs and retinoids are commonly used. However, these treatments may have adverse effects in the long term. Conversely, systemic conventional treatments include immunosuppresors such as cyclosporin or methotrexate associated with high toxicity levels. Biologicals are alternative therapeutical agents introduced in the last 10 years. These include fusion proteins or monoclonal antibodies designed to inhibit the action of specific cytokines or to prevent T-lymphocyte activation. However, due to recent knowledge on the etiology of the disease, diverse new small molecules have appeared as promising alternatives for the treatment of psoriasis. Among them, inhibitors of JAK3, inhibitors of PDE 4 and amygdalin analogs. The latter are promising small molecules presently in preclinical studies which are the object of the present report.
Asunto(s)
Amigdalina/uso terapéutico , Antineoplásicos Fitogénicos/uso terapéutico , Psoriasis/tratamiento farmacológico , Amigdalina/análogos & derivados , Amigdalina/farmacocinética , Animales , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacocinética , Humanos , Inhibidores de Fosfodiesterasa 4/química , Inhibidores de Fosfodiesterasa 4/farmacocinética , Inhibidores de Fosfodiesterasa 4/uso terapéutico , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacocinética , Inhibidores de Proteínas Quinasas/uso terapéutico , Relación Estructura-Actividad , Linfocitos T/inmunología , Linfocitos T/metabolismoRESUMEN
Evidence is accumulating that glucose-conjugated compounds may be carried across the gut mucosa via the epithelial sodium-dependent monosaccharide transporter SGLT1. A modification of the everted intestinal sac technique was utilized to study the transport of the cyanogenic glycoside amygdalin (D-mandelonitrile beta-D-gentiobioside) and its metabolite D-mandelontrile beta-D-glucoside (prunasin). Everted sacs of rat jejunum and ileum were bathed in isotonic oxygenated sodium chloride-potassium phosphate buffer containing 2.8 microCi D-[(3)H]-mannose and 0.187 microCi D-[(14)C]-glucose. For treatment groups, buffers contained phloridzin, galactose, amygdalin or prunasin. The rate constant (k) for the transport process was calculated. Compared with the control (n = 33), phloridzin (n = 25) significantly reduced the rate constants of both D-[(14)C]-glucose and D-[(3)H]-mannose. Substitution of sodium with choline and incremental galactose treatments similarly reduced D-[(14)C]-glucose influx, indicating that a fraction of the transport is carrier-mediated. Treatment with amygdalin did not significantly affect the rate constants of D-[(14)C]-glucose or D-[(3)H]-mannose transport. However, treatment with 1 mM prunasin (n = 16) did reduce the influx of D-[(14)C]-glucose without affecting D-[(3)H]-mannose values. This is consistent with the reports finding that glycoside absorption may be mediated by SGLT1.
Asunto(s)
Amigdalina/farmacocinética , Hexosas/metabolismo , Absorción Intestinal , Nitrilos/farmacocinética , Animales , Transporte Biológico , Femenino , Ratas , Ratas Long-Evans , Factores de TiempoRESUMEN
A DNA polymerase beta (pol. beta) inhibitor has been isolated independently from two organisms; a red perilla, Perilla frutescens, and a mugwort, Artemisia vulgaris. These molecules were determined by spectroscopic analyses to be the cyanogenic glucoside, D-mandelonitrile-beta-D-glucoside, prunasin. The compound inhibited the activity of rat pol. beta at 150 microM, but did not influence the activities of calf DNA polymerase alpha and plant DNA polymerases, human immunodefficiency virus type 1 reverse transcriptase, calf terminal deoxynucleotidyl transferase, or any prokaryotic DNA polymerases, or DNA and RNA metabolic enzymes examined. The compound dose-dependently inhibited pol. beta activity, the IC(50) value being 98 microM with poly dA/oligo dT(12-18) and dTTP as the DNA template and substrate, respectively. Inhibition of pol. beta by the compound was competitive with the substrate, dTTP. The inhibition was enhanced in the presence of fatty acid, and the IC(50) value decreased to approximately 40 microM. In the presence of C(10)-decanoic acid, the K(i) value for substrate dTTP decreased by 28-fold, suggesting that the fatty acid allowed easier access of the compound to the substrate-binding site.
Asunto(s)
ADN Polimerasa beta/antagonistas & inhibidores , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacocinética , Nitrilos/química , Nitrilos/farmacocinética , Amigdalina/química , Amigdalina/farmacocinética , Animales , Artemisia/química , Artemisia/enzimología , Bovinos , Ácidos Decanoicos/farmacología , Didesoxinucleótidos , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/aislamiento & purificación , Humanos , Concentración 50 Inhibidora , Cinética , Lamiaceae/química , Nitrilos/aislamiento & purificación , Plantas Medicinales , Ratas , Nucleótidos de Timina/químicaRESUMEN
We report the case of a 56-year-old woman who was accidentally poisoned when she ingested choke cherries whose pulp contained cyanide, and describe the acute clinical picture, the neurological sequelae and the neuroradiological findings. After recovery from coma, the patient showed signs of a parkinsonian syndrome, retrobulbar neuritis and sensory-motor neuropathy. MRI showed abnormal signal intensities involving the basal ganglia. Since no memory deficits were observed, we argue that the parkinsonian syndrome was caused by cyanide intoxication rather than by subcortical damage due to hypoxia.