Simultaneous determination of seven major isosteroidal alkaloids in bulbs of Fritillaria by gas chromatography

A distinction between Fritillaria Cirrhosa Bulbus and Fritillaria Pallidiflora Bulbus via LC-MS/MS in conjunction with principal component analysis and hierarchical cluster analysis

Fritillaria Cirrhosa Bulbus (known as chuanbeimu in Chinese, FCB) is one of the most used Chinese medicines for lung disease. However, a variety of substitutes have entered the market, with Fritillaria Pallidiflora Bulbus (FPB) being the most common. Due to their similarity in appearance, morphology, and chemical composition but a large price difference, the FCB has frequently been adulterated with the FPB, posing a serious challenge to the distinction and quality of the FCB. Therefore, we aimed to distinguish FCB and FPB based on their main nine isosteroidal alkaloid contents and test the potential of chemometrics as a discrimination approach for evaluating quality. The nine major isosteroidal alkaloids were measured using a liquid chromatography with tandem mass spectrometry (LC-MS/MS) approach in 41 batches of FCB and 17 batches of FPB. Additionally, they were categorized and distinguished using the methods of hierarchical cluster analysis (HCA) and principal component analysis (PCA). Quantitative analysis revealed that the nine alkaloids were present in different amounts in the two types of Fritillariae bulbus. In FCB, the highest amount was peimisine (17.92-123.53 μg/g) and the lowest was delavine (0.42-29.18 μg/g), while in FPB, imperialine was higher (78.05-344.09 μg/g), but verticinone and verticine were less than the other seven alkaloids. The FCB and FPB were successfully classified and distinguished by the HCA and PCA. Taken together, the method has a good linear relationship (R² > 0.9975). The LOD and LOQ of the nine alkaloids were in the range of 0.0651-0.6510 and 0.1953-1.9531 ng/mL, respectively. The intra- and inter-day precision were shown to be excellent, with relative standard deviations (RSDs) below 1.63% and 2.39%, respectively. The LC-MS/MS method in conjunction with HCA and PCA can effectively differentiate FCB and FPB. It may be a promising strategy for quality evaluation and control at the FCB.

LC–MS/MS Coupled with Chemometric Analysis as an Approach for the Differentiation of Fritillariae cirrhosae Bulbus and Fritillariae pallidiflorae Bulbus

Fritillariae cirrhosae bulbus (FCB) is one of the most important traditional Chinese medicines (TCM) for the treatment of cough and phlegm. Due to increasing demand and the complexity of FCB’s botanical origin, various substitutes have appeared in the market, resulting in a major challenge to distinguish FCB and its substitutes (F. pallidiflorae bulbus, FPB). Therefore, discriminating FCB from FPB has becoming an urgent necessity. In this study, an ultra-high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UPLC–ESI–MS/MS) method was developed for the simultaneous quantification of nine steroidal alkaloids (imperialine-3-β-D-glucoside, imperialine, verticine, verticinone, peimisine, yibeinoside A, delavine, delavinone, ebeidinone) within 8 min. According to the composition and content of the above nine compounds, multivariate chemometric analyses were applied for the classification of FCB and FPB. The quantitative results showed that there were both similarities and differences in the content of nine steroidal alkaloids between FCB and FPB, and it was difficult to directly distinguish these two species. Fortunately, with the aid of chemometric analyses, FCB and FPB were successfully differentiated by partial least squares discrimination analysis (PLS-DA) and orthogonal partial least squares discrimination analysis (OPLS-DA) models based on the nine alkaloids’ content. Moreover, four compounds (yibeinoside A, ebeiedinone, delavinone and imperialine) were discovered as potential markers for the identification and differentiation of FCB and FPB. Additionally, compared to other studies, this work collected a large number of samples (49 batches of FCB and 17 batches of FPB) to ensure the reliability of the results. In conclusion, this work established a new approach for the authentication of FCB based on its active components, which provides a good reference for the quality control of FCB and will help us to understand the chemical composition differences between FCB and its adulterants further.

Natural drug sources for respiratory diseases from Fritillaria: chemical and biological analyses

Fritillaria naturally grows in the temperate region of Northern Hemisphere and mainly distributes in Central Asia, Mediterranean region, and North America. The dried bulbs from a dozen species of this genus have been usually used as herbal medicine, named Beimu in China. Beimu had rich sources of phytochemicals and have extensively applied to respiratory diseases including coronavirus disease (COVID-19). Fritillaria species have alkaloids that act as the main active components that contribute multiple biological activities, including anti-tussive, expectorant, and anti-asthmatic effects, especially against certain respiratory diseases. Other compounds (terpenoids, steroidal saponins, and phenylpropanoids) have also been identified in species of Fritillaria. In this review, readers will discover a brief summary of traditional uses and a comprehensive description of the chemical profiles, biological properties, and analytical techniques used for quality control. In general, the detailed summary reveals 293 specialized metabolites that have been isolated and analyzed in Fritillaria species. This review may provide a scientific basis for the chemical ecology and metabolomics in which compound identification of certain species remains a limiting step.

LC-MS/MS coupled with chemometric analysis as an approach for the differentiation of bulbus Fritillaria unibracteata and Fritillaria ussuriensis

INTRODUCTION

Bulbus Fritillaria unibracteata Hsiao et K.C. Hsia is an important traditional Chinese medicine, widely used for the treatment of coughs, phlegm and asthma for thousands of years. Due to an increasing demand in clinic practices, a variety of substitutes have appeared in the market, resulting in a big challenge in the differentiation of bulbus F. unibracteata and its substitutes.

AIM

To differentiate bulbus F. unibracteata and its substitutes (bulbus Fritillaria ussuriensis Maxim.) based on their main isosteroidal alkaloid contents, and to test the potentiality of chemometrics as a tool for discrimination.

MATERIALS AND METHODS

The nine isosteroidal alkaloids in 61 batches of Fritillariae bulbus were simultaneously quantitated by liquid chromatography with tandem mass spectrometry (LC-MS/MS) method. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied to classify the two kinds of Fritillariae bulbus.

RESULTS

Quantitative analysis showed that there were differences in the content of the nine alkaloids between two kinds of Fritillariae bulbus. According to the content of nine isosteroidal alkaloids, bulbus of F. unibracteata and F. ussuriensis were successfully distinguished by PCA model. Among these isosteroidal alkaloids, verticine and verticinone may be used as potential chemical markers for the identification and differentiation between the two kinds of Fritillaria bulbus.

CONCLUSION

The LC-MS/MS method coupled with PCA would be a powerful strategy to differentiate bulbus F. unibracteata and substitute specimens for quality evaluation and control.

Pharmacokinetics of ebeiedinone in mouse blood by UPLC–MS/MS

An ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was established to determine ebeiedinone in mouse blood, and the pharmacokinetics of ebeiedinone after intravenous (0.5 mg/kg) and oral (2, 4, and 8 mg/kg) administration was studied. Twenty-four mice were randomly divided into 4 groups, 1 group was for intravenous administration (0.5 mg/kg), and other 3 groups were for oral administration (2, 4, and 8 mg/kg), with 6 rats in each group. Yubeinine was used as an internal standard. Multiple reaction monitoring (MRM) mode was used to quantitatively analyzed ebeiedinone m/z 414.4 → 91.1 and the internal standard m/z 430.4 → 412.3 in the electrospray ionization (ESI) positive interface. In the concentration range of 1–2000 ng/mL, the ebeiedinone in the mouse blood was linear (r2 > 0.995), and the lower limit of quantification was 1.0 ng/mL. In the mouse blood, the intra-day precision coefficient of variation (CV) was less than 15%, and the inter-day precision CV was less than 15%. The accuracy ranged from 85.4% to 114.6%, and the average recovery was higher than 61.3%. The matrix effect was between 87.0% and 106.5%. These data met the pharmacokinetic study requirements of ebeiedinone. The UPLC–MS/MS method was sensitive, rapid, and selective and was successfully applied to the pharmacokinetic study of ebeiedinone in mice. The absolute bioavailability of ebeiedinone was 30.6%.

Effect of superfine grinding on the physicochemical properties of bulbs of Fritillaria unibracteata Hsiao et K.C. Hsia powder

This work aimed to determine the influence of superfine grinding on the physicochemical properties of bulbs of Fritillaria unibracteata Hsiao et K.C. Hsia (BFU) powder. For this purpose, fine powder (FP) and two superfine powders (SPs) were obtained via superfine and conventional grinding methods. The properties of different powders were studied and compared. Compared with FP, SPs exhibited higher values in terms of the angle of repose, swelling capacity, ethanol extraction yield, total alkaloid content, and imperialine content, while lower values in terms of particle size and bulk density. Especially, the total alkaloid content of SP-I increased by 66.7%. Proper grinding is more conducive to reduce particle size and improve alkaloid content. FTIR analysis indicates that no new functional groups produced after superfine grinding. XRD analysis suggests that grinding treatment lead to decreases in the crystallinity. Therefore, superfine grinding displays immense potential in the BFU application.

Fritillariae Thunbergii Bulbus: Traditional Uses, Phytochemistry, Pharmacodynamics, Pharmacokinetics and Toxicity

Fritillariae Thunbergii Bulbus (FTB) has been widely used as an antitussive herb for thousands of years in China. However, FTB's traditional uses, chemical compounds and pharmacological activities have not been systematically reviewed. This study aimed to review its traditional uses, phytochemistry, pharmacodynamics, pharmacokinetics and toxicity. We searched the Encyclopedia of Traditional Chinese Medicine to explore the historical records which indicate that it acts to clear heat, resolve phlegm, relieve cough, remove toxicity and disperse abscesses and nodules. We searched 11 databases to identify potential phytochemical or pharmacological studies. Characteristics of its chemical constituents, pharmacological effects, pharmacokinetic and toxicity were descriptively summarized. A total of 9706 studies were identified and 83 of them were included. As a result, 134 chemical constituents were identified, including 26 alkaloids, 29 compounds found in essential oils, 13 diterpenoids, two carbohydrates, two sterols, 18 amino acids, six nucleosides, four nucleobases, four fatty acids, three lignans, and 27 elements. Thirteen pharmacological effects of FTB were identified, including anti-cancer, tracheobronchial relaxation, antitussive, expectorant, anti-muscarinic, anti-inflammation, anti-thyroid, regulation of blood rheology, antiulcer, anti-diarrhea, pain suppression, antioxidation and neuroprotection. These pharmacological activities may be mainly attributed to the alkaloids in FTB. Further phytochemical, pharmacological and network pharmacological studies are recommended.

Investigation of association of chemical profiles with the tracheobronchial relaxant activity of Chinese medicinal herb Beimu derived from various Fritillaria species

ETHNOPHARMACOLOGICAL RELEVANCE

Fritillariae Bulbus (Beimu in Chinese) is derived from the bulbus of many Fritillaria species (family Liliaceae), which has been used as an antitussive herb in traditional Chinese medicine for more than 2000 years. Due to the complexity of plant origins and significant variations in chemical profiles, the characterization of the profile of the major bioactive constituents and its association with pharmacological activity are important for the quality control of Beimu herbs from different origins.

AIM OF THE STUDY

This study aims to investigate the distribution of major bioactive isosteroidal alkaloids in Beimu herbs of different origins and its correlation with the tracheobronchial relaxant activity.

METHODS

Quantification of 7 main bioactive 5α-cevanine isosteroidal alkaloids, including ebeiedine, ebeiedinone, hupehenine, isoverticine, verticine, verticinone and imperialine, in 23 Fritillaria species was performed using gas chromatography. The relaxant effect of different extracts of 4 commonly used Beimu herbs, namely Zhe-Beimu (F. thunbergii Miq.), Chuan-Beimu (F. cirrhosa D. Don), Hubei-Beimu (F. hupehensis Hsiao et K. C. Hsia) and Yi-Beimu (F. pallidiflora Schrenk), was evaluated using rat isolated tracheal and bronchial preparations pre-contracted with carbachol, the well established in vitro antitussive model.

RESULTS

Amongst 23 Fritillaria species detected, significant variations of the types and quantities of 7 major isosteroidal alkaloids were determined, which served as an important indicator for the classification of different Beimu herbs with distinct geographic distributions. Based on the type and quantity of these alkaloids, different origins of Beimu could be clearly clustered into several subgroups by principal component analysis. Furthermore, both crude alkaloid and water extracts of all 4 Beimu herbs showed a dose-dependent tracheobronchial relaxation with different potencies. The total content of alkaloids (weight adjusted based on the activity of individual alkaloids) in Beimu extracts significantly correlated with their tracheobronchial relaxation effects (r² > 0.9, p < 0.001).

CONCLUSIONS

The results demonstrated that the differences in chemical profile of major bioactive isosteroidal alkaloids and pharmacological activity of Beimu could be incorporated into a simple and unified method for quality control and potential prediction of activity of Beimu herbs from different origins.

A non-derivative method for the quantitative analysis of isosteroidal alkaloids from Fritillaria by high performance liquid chromatography combined with charged aerosol detection

A non-derivative method was developed for the qualitative and quantitative analysis of isosteroidal alkaloids from Fritillaria thunbergii. During method development the performance of two universal detectors, the charged aerosol detector (CAD) and evaporative light scattering detector (ELSD), were evaluated. The CAD was found to be 30 to 55 times more sensitive than ELSD enabling the measurement of low levels of reference compound impurities that could not be detected by ELSD. The peak area percent of the reference compound, peimisine, obtained by CAD was 50.10%, but 91.66% by ELSD showing that CAD is suitable to estimate the presence of impurities. The CAD showed good reproducibility with overall intra- and inter-day peak area RSD values of less than 1.8% and 2.7%, respectively and had a linear dynamic range of up to 4 orders of magnitude (0.06-44mg/L) for peimine and peiminine. The optimized method was used for the quantitative analysis of peimine and peiminine from F. thunbergii.

Simultaneous Determination of Five Alkaloid Compounds in a Drug Based on a Hydrophilic Monolithic Column by Capillary Electrochromatography

A novel capillary electrochromatography (CEC) method was developed by using a hydrophilic monolithic column for the simultaneous determination of five alkaloids in a drug. The monolithic stationary phase was first prepared via in situ polymerization of acrylamide (AM), glycidyl methacrylate (GMA), N,N'-methylenebisacrylamide (MBA) and 2-acrylamido-2-methyl-1-propane-sulfonic acid (AMPS) in a ternary porogen solvent system consisting of cyclohexanol, dodecanol and toluene. The obtained monolithic stationary phase was subsequently modified by 0.1 mol/L ammonia water for opening epoxide groups of GMA. The separation performance and efficiency of the resulting monolithic column were investigated by the use of five compounds (thiourea, aniline, naphthylamine, diphenylamine and dimethyl acetamide) by CEC. The optimized monolithic column has obtained high column efficiencies with 74,000-121,000 theoretical plates/m. Finally, the prepared monolithic column was used to separate and determine five alkaloids (piperine, nuciferine, kukoline, berberine and tetrandrine) using CEC. Under the conditions of acetonitrile/10 mM phosphate buffer solution (65/35, v/v, pH 8.5) and 15 kV applied voltage, the baseline separation of five alkaloids was achieved. The proposed method has been successfully applied to the determination of berberine in a tablet sample. The percentage of recovery of spiked tablet samples ranged from 93.4 to 108.0% with relative standard deviations (RSDs) <9.20%.

Inhibition of Sortase, a Bacterial Surface Protein Anchoring Transpeptidase, by β-Sitosterol-3-O-glucopyranoside fromFritillaria verticillata

A glucosylsterol, beta-sitosterol-3-O-glucopyranoside, has been isolated as an active principle with sortase inhibitory effect from the bulbs of Fritillaria verticillata by bioassay-guided chromatographic fractionation. The isolate was a potent inhibitor of sortase, with an IC(50) value of 18.3 microg/ml and had antibacterial activity against Bacillus subtilis, Staphylococcus aureus, and Micrococcus leuteus with MIC values of 50, 200, and 400 microg/ml, respectively, indicating that this compound is a possible candidate for the development of a bacterial sortase inhibitor. In addition, sitosterol was found to be inactive upon sortase and bacterial cell growth. These results suggest that the inhibitory potency of beta-sitosterol-3-O-glucopyranoside is sensitively dependent upon the glucopyranoside side chain moiety.

Sex dependent pharmacokinetics, tissue distribution and excretion of peimine and peiminine in rats assessed by liquid chromatography-tandem mass spectrometry

ETHNOPHARMACOLOGICAL RELEVANCE

Fritillaria thunbergii Miq. has been traditionally used in China as antitussive and expectorant herbs, and newly used in the clinical treatment of leukemia in recent years.

AIM

To investigate whether gender exerted a significant influence on the pharmacokinetics, tissue distribution and excretion of peimine and peiminine in Sprague-Dawley rats who were given a single oral administration of 4.25 g/kg Fritillaria thunbergii Miq. extract.

MATERIALS AND METHODS

Sprague-Dawley rats were assigned into two groups based on the gender and orally administered 4.25 g/kg Fritillaria thunbergii Miq. extract for each individual pharmacokinetics, tissue distribution and excretion study.

RESULTS

Compared with female rats, peimine and peiminine were eliminated slowly from male rat plasma, and significant gender-related differences were observed in the pharmacokinetic parameters. Drug blood and tissue levels in male rats were significantly higher than the female counterparts except for several tissues, such as fat, muscle and skin. Gender also exerted a significant influence on the urine excretion but such effect was not observed in the feces excretion study.

CONCLUSIONS

Gender exerted a significant influence on the pharmacokinetics, tissue distribution and urine excretion of peimine and peiminine. It is assumed that the sex-associated differences of peimine and peiminine in rats might be mainly result from sex-dependent expression and activity of drug metabolism enzymes and P-glycoprotein.

Determination of peimine and peiminine in Bulbus Fritillariae Thunbergii by capillary electrophoresis by indirect UV detection using N-(1-naphthyl)ethylenediamine dihydrochloride as probe

A simple and inexpensive CE method was developed for the determination of peimine and peiminine. Because of the lack of an UV chromophore of peimine and peiminine, the detection method chosen was indirect UV detection, with N-(1-naphthyl)ethylenediamine dihydrochloride (NED) as the UV absorbing probe. It was thought that NED, a chromophoric ion, may form hydrogen bonding pairs with the analytes to cause significant changes in separation selectivity. Additionally, the hydrophobic interactions between analytes and the probe also play a crucial role in achieving a resolution between the two analytes. The analyses were carried out with a background electrolyte composed of 66% MeOH-ACN (1:1, v/v), 34% aqueous buffer containing 15 mM NaH₂PO₄, 2.5 mM NED, 4 mM H₃PO₄. MeOH-ACN mixtures used as organic modifiers can not only reduce the adsorption of NED to the capillary wall, but also decrease the baseline noise and drift. The method provided a linear response ranging from 5 to 200 μg/mL. The limits of detection (LODs) for peimine and peiminine were 3.9 and 4.1 μg/mL, respectively. The repeatabilities (n = 3) reached relative standard deviation values (RSDs) of 3.4 and 4.1% for the peak areas, 4.0 and 4.4% for the peak heights, and 0.29 and 0.30% for the migration time of peimine and peiminine, respectively. Regression equations revealed linear relationships (r = 0.9995-0.9996) between the peak area of each analyte and the concentration. The method developed was successfully applied to quantify peimine and peiminine in chloroform extracts of the ground Bulbus Fritillariae Thunbergii.

More accurate matrix-matched quantification using standard superposition method for herbal medicines

Various analytical technologies have been developed for quantitative determination of marker compounds in herbal medicines (HMs). One important issue is matrix effects that must be addressed in method validation for different detections. Unlike biological fluids, blank matrix samples for calibration are usually unavailable for HMs. In this work, practical approaches for minimizing matrix effects in HMs analysis were proposed. The matrix effects in quantitative analysis of five saponins from Panax notoginseng were assessed using high-performance liquid chromatography (HPLC). Matrix components were found to interfere with the ionization of target analytes when mass spectrometry (MS) detection were employed. To compensate the matrix signal suppression/enhancement, two matrix-matched methods, standard addition method with the target-knockout extract and standard superposition method with a HM extract were developed and tested in this work. The results showed that the standard superposition method is simple and practical for overcoming matrix effects for quantitative analysis of HMs. Moreover, the interference components were observed to interfere with light scattering of target analytes when evaporative light scattering detection (ELSD) was utilized for quantitative analysis of HMs but was not indicated when Ultraviolet detection (UV) were employed. Thus, the issue of interference effects should be addressed and minimized for quantitative HPLC-ELSD and HPLC-MS methodologies for quality control of HMs.

Simultaneous determination of peimine and peiminine in rat plasma by LC-ESI-MS employing solid-phase extraction

A simple and reliable LC-ESI-MS method for the determination of peimine and peiminine in rat plasma was developed for the first time. The method was proven to be specific and sensitive by carrying out validation. The analytes were extracted from rat plasma via solid-phase extraction on Waters Oasis MCX cartridges. Chromatography separation was achieved on a C(18) column using 10 mM ammonium acetate (adjusted to pH 3.0 with glacial acetic acid)-acetonitrile (85:15, v/v) as mobile phase. The linear range was 1-100 ng/mL for peimine and peiminine. Intra- and inter-day precisiond were less than 10%. Accuracies were within 85-115% of their nominal concentrations. The limit of quantification was 1 ng/mL for both analytes. The developed assay was successfully applied to pharmacokinetic study of peimine and peiminine in rats orally administered the alkaloids extracts from Bulbus Fritillariae, demonstrating a possible broader spectrum of applications of this method.

Simultaneous determination of nine nucleosides and nucleobases in different Fritillaria species by HPLC-diode array detector

A sensitive and reliable HPLC-diode-array detector method was developed for the first time to simultaneously determine nine nucleosides and nucleobases including uracil, cytidine, guanine, uridine, thymine, inosine, guanosine, thymidine and adenosine in 13 different Fritillaria species. The analysis was performed on a BaseLine C18 column with a gradient of acetonitrile in water at a flow rate of 0.8 mL/min. The diode-array detector wavelength was set at 260 nm for the UV detection of nucleosides and nucleobases. Satisfactory separation of these compounds was obtained in less than 40 min. The optimized method provided good linear relation (r(2)>0.9995 for all the investigated analytes), satisfactory precision (RSD <1.51%) and good recovery (from 97.64 to 101.16%). The established method was successfully applied to simultaneous determination of nine nucleosides and nucleobases in 61 batches of samples from 13 Fritillaria species collected from different habitats in China, which could be helpful to control the quality of Fritillaria bulbs.

Superoxide dismutase activity and isoenzyme profiles in bulbs of snake's head fritillary in response to cold treatment

The activities and isoenzyme profiles of superoxide dismutase (SOD) in in vitro Fritillaria meleagris bulbs in response to cold treatment (4?C) were investigated. Differences in SOD activity and isoenzyme profiles in bulbs under standard growth conditions, six weeks chilling, as well as seven days after the completion of cold treatment are presented. SOD activity initially decreased but then rapidly increased seven days after cold treatment. Four isoforms of SOD are active under standard and chilling conditions, while three isoforms are presented 7 days after cold treatment. Native gel electrophoresis indicated the presence of mitochondrial and chloroplast localized SODs. .

Indirect somatic embryogenesis from petal explant of endangered wild population of Fritillaria imperialis

Fritillaria imperialis is an endangered bulbous plant and therefore in vitro micropropagation of this plant will have a great importance for germplasm conservation and commercial production. Petal explants, for the first time, were cultured on media containing various concentrations of plant growth regulators. In addition, the effects of cold pretreatment and light on induction and regeneration of somatic embryogenesis trough callus were studied in detail. Cold pretreatment had inhibitory effects on somatic embryogenesis pathway. Among the different combinations of 6-Bnzylaminopurine (BAP), alpha-naphthaleneacetic acid (NAA) and indole-3-aceticacid (IAA) tested, B5 medium supplemented with 0.1 mg L(-1) BAP + 0.6 mg L(-1) NAA + 0.4 mg L(-1) IAA was the best treatment for bulblet production (6 bulblets per somatic embryogenesis callus). This research presents petal as a reliable material for micropropagation and germplasm conservation of Fritillaria imperialis.

Effects of bulbus Fritillaria water extract on blood pressure and renal functions in the L-NAME-induced hypertensive rats

A pharmacological inhibition of nitric oxide synthase (NOS) in rats produces renal vasoconstriction, renal dysfunction, and hypertension. The present study was aimed at investigating whether Bulbus Fritillaria water extract (BFWE) ameliorates NG-nitro-L-arginine methylester (L-NAME)-induced hypertension. Treatment of rats with L-NAME (60 mg/l drinking water, 4 weeks) caused a sustained increase in systolic blood pressure (SBP). The NO concentration in plasma and NO productions in the vascular tissues of the L-NAME-treated group were significantly reduced as compared with those in the control, whereas the expressions of NOS proteins were not altered. BFWE restored SBP to normal level in the L-NAME-treated hypertensive rats. Moreover, BFWE was able to preserve the vascular NO production and plasma NO metabolites concentration without changes of the expression NOS proteins. The renal functional parameters including urinary volume, sodium excretion, and creatinine clearance (Ccr) were significantly restored in rats co-treated with BFWE and L-NAME compared to the L-NAME-treated group. Taken together, these results suggest that BFWE prevents the increase of SBP in the L-NAME-induced hypertension that may have been caused by enhanced generation of vascular NO and amelioration of renal functions.

Effects of bulb of Fritillaria ussuriensis maxim. on angiotensin converting enzyme and vascular release of NO/cGMP in rats

The present study was designed to investigate whether the Bulbus Fritillaria shows a hypotensive effect via the angiotensin converting enzyme (ACE) inhibition and elicit NO/cGMP release in rat aortic rings. Intravenous injection of Bulbus Fritillaria water extract lowered the mean arterial pressure of anesthetized rats in a dose-dependent manner. The ACE activities were inhibited significantly by the additions of ethylacetate and butanol extracts from Bulbus Fritillaria, of which IC(50) values were 292 and 320 microg/ml, respectively. Moreover, angiotensin I-induced vasoconstriction was also strongly inhibited by the additions of ethylacetate and butanol extracts from Bulbus Fritillaria. In order to assess whether NO production was induced by Bulbus Fritillaria extracts, we directly measured NO and cGMP production levels from the aortic ring elicited by extracts of Bulbus Fritillaria. Our results showed that the hexane, butanol, and water extracts of Bulbus Fritillaria increased NO and cGMP productions in intact vascular tissue. These findings suggest that Bulbus Fritillaria extracts have a hypotensive effect in rats via the inhibition of ACE activity and direct release of NO/cGMP in the vascular tissue.

The extraction of imperialine and imperialine-3 beta-glucoside from Fritillaria pallidiflora Schrenk and quantitative determination by HPLC-evaporative light scattering detection

The extraction procedure and quantitative determination by HPLC-evaporative light scattering detection (ELSD) of the main bioactive components, namely, imperialine (1) and imperialine-3 beta-glucoside (2), of bulbs of Fritillaria pallidiflora Schrenk have been investigated. The most efficient method for the simultaneous extraction of 1 and 2 involved pre-treatment of the bulb powder with ammonia, followed by reflux with dichloromethane:methanol at 90 degrees C for 4 h. Simultaneous determination of non-chromophoric 1 and 2 by HPLC-ELSD employed a Kromasil C18 column eluted with acetonitrile:water:diethylamine. The assay was accurate and reproducible with an overall variation lower than 4% and a sample recovery higher than 98%. The methods described have been successfully used to evaluate the quality of three batches of the crude traditional Chinese medicinal herb derived from the bulbs of F. pallidiflora.

Gas chromatography and high-performance liquid chromatography of natural steroids

This review article underlines the importance of gas chromatography (GC), high-performance liquid chromatography (HPLC) and their hyphenated techniques using mass spectrometry (MS) for the determination of natural steroids, especially in human biological fluids. Steroids are divided into eight categories based on their structures and functions, and recent references using the above methodologies for the analysis of these steroids are cited. GC and GC-MS are commonly used for the determination of volatile steroids. Although HPLC is a widely used analytical method for the determination of steroids including the conjugated type in biological fluids, LC-MS is considered to be the most promising one for this purpose because of its sensitivity, specificity and versatility.

Chromatographic analysis of Fritillaria isosteroidal alkaloids, the active ingredients of Beimu, the antitussive traditional Chinese medicinal herb

Bulbus Fritillariae derived from plants of various Fritillaria species is the most commonly used antitussive traditional Chinese medicinal herb and is called Beimu. Herbs derived from similar and/or different species of Fritillaria are also used in Japan and Turkey as traditional or folk medicines. Isosteroidal alkaloids are the main bioactive ingredients in Fritillaria species. As the contents and structure types of these bioactive alkaloids vary in different Fritillaria species, quality control of these active principles in herbal Beimu is very important to ensure its safe and effective clinical use. This review describes the development of chromatographic analyses for the simultaneous qualitative and quantitative determination of the main bioactive Fritillaria isosteroidal alkaloids in herbal and biological samples. The recently developed direct HPLC-evaporative light scattering detection method is the most simple, selective and sensitive assay, and is readily used as a suitable quality control method for the analysis of the active principles of herbal Beimu.

Determination of the major isosteroidal alkaloids in bulbs of Fritillaria by high-performance liquid chromatography coupled with evaporative light scattering detection

A new direct HPLC analytical method using evaporative light scattering detection coupled with a low-temperature adapter for the simultaneous determination of the major biologically active isosteroidal alkaloids in Bulbus Fritillariae, a commonly used antitussive traditional Chinese medicinal (TCM) herb, has been developed. The simultaneous separation of eight Fritillaria alkaloids was achieved on a reversed-phase C8 column with an isocratic mobile phase system consisting of acetonitrile-methanol-water (66.5:3.5:30, v/v) containing 0.006% triethylamine. This method provides good reproducibility and sensitivity for the quantification of six major isosteroidal alkaloids, namely peimissine, verticine, verticinone, imperialine, isoverticine and ebeiedine in different Fritillaria species with overall intra- and inter-day precision and accuracy of less than 11% and higher than 90%, respectively. The assay was successfully utilized to quantify the major biologically active alkaloids in five Fritillaria species. The results demonstrate that this method is simple, selective, and suitable for the quality control of this commonly used antitussive TCM herb, Bulbus Fritillariae. reserved.