Identification and quantification of baicalein, wogonin, oroxylin A and their major glucuronide conjugated metabolites in rat plasma after oral administration of Radix scutellariae product

The current study aims to identify and quantify three flavones (baicalein, wogonin and oroxylin A) and their major metabolites (baicalin, wogonoside and oroxylin A-7-O-glucuronide) in rat plasma after oral administration of Radix scutellariae product. A simple HPLC/UV method has been developed to simultaneously determine the three flavones and their major metabolites in rat plasma. The chromatographic separation of the six analytes was achieved by a Thermo C(18) column with linear gradient elution of a mobile phase containing acetonitrile and 20mM sodium dihydrogen phosphate buffer (pH 4.6). All the tested analytes were detected by PDA detector at a wavelength of 320nm. The intra-day and inter-day precision for the current assay of the six analytes was within the range of -2.23% to 15.13% and -10.83% to 6.42%, respectively. All the studied analytes could be efficiently extracted from the rat plasma using HLB cartridge with extraction recoveries above 70% and were stable under different storage conditions. The developed assay method was successfully applied to the pharmacokinetic study of baicalin, wogonoside after oral administration of a commercially available Radix scutellariae containing capsule at a dose of 3.2g/kg to Sprague-Dawley rats. In addition to wogonoside, a new metabolite of wogonin has been identified using LC/MS/MS for the first time.     

Pharmacological effects and pharmacokinetics properties of Radix Scutellariae and its bioactive flavones

Radix Scutellariae is the dried root of the medicinal plant Scutellariae baicalensis Georgi. It exhibits a variety of therapeutic effects and has a long history of application in traditional formulations as well as in modern herbal medications. It has been confirmed that flavonoids are the most abundant constituents and induce these therapeutic effects. Six flavones are proven to be the major bioactive flavones in Radix Scutellariae existing in the forms of aglycones (baicalein, wogonin, oroxylin A) and glycosides (baicalin, wogonoside, oroxylin A-7-glucuronide). All six flavones are pharmacologically active and show great potential in the treatment of inflammation, cancers and virus-related diseases. The current review covers the preparation of the herb Radix Scutellariae, quantification of its major bioactive ingredients, and pharmacological effects of the proposed six bioactive flavones. In addition, this review summarizes the pharmacokinetic profiles of the bioactive flavones reported so far that could be used for further improvement of their pharmacokinetic study. Moreover, due to abundant co-occurring bioactive components in Radix Scutellariae, our review further documents the pharmacokinetic interactions among them.     

HPLC–MS and HPLC–MS/MS analysis of seven active constituents of Xiao-Xu-Ming decoction and application to a pharmacokinetic study after oral administration to rat

Xiao-xu-ming decoction (XXMD) is a traditional Chinese medicine that has been widely used to treat theoplegia and its sequelae. This paper reports the development of three separate assays based on reversed phase high-performance liquid chromatography–mass spectrometry (HPLC–MS) and HPLC–MS/MS for the determination of seven active constituents of XXMD viz oroxylin A-7-O-glucuronide, wogonoside, liquiritigenin, cimifugin, 5-O-methylvisammiol, glycyrrhizic acid and glycyrrhetinic acid in rat plasma. All calibration curves were linear (r >0.99) with lower limits of quantitation (LLOQs)<12.4 ng/mL. Intra- and inter-day precisions (as relative standard deviation) were all <10.7% with recoveries in the range of 88.7–113%. In addition, the seven analytes were shown to be stable in rat plasma samples under relevant storage conditions. The validated methods were successfully applied to a pharmacokinetic study in rat after oral administration of XXMD.     

Regioselective sulfonation of dopamine by SULT1A3 in vitro provides a molecular explanation for the preponderance of dopamine-3-O-sulfate in human blood circulation

SULT1A3 is an enzyme that catalyzes the sulfonation of many endogenous and exogenous phenols and catechols. The most important endogenous substrate is dopamine (DA), which is often used as a probe substrate for SULT1A3. We developed a new method for analyzing the SULT1A3 reaction products by high-performance liquid chromatography (HPLC) with electrochemical detection. The sulfonate donor 3′-phosphoadenosine-5′-phosphosulfate (PAPS), DA and the two dopamine sulfates, DA-3-O-sulfate and DA-4-O-sulfate, can be separated within 3 min. This enables quantitation of the sulfates without radioactive PAPS or the precipitation of unreacted PAPS. Both sulfates were synthesized as reference substances and characterized by ¹H and ¹³C nuclear magnetic resonance (NMR), mass spectrometry (MS) and tandem mass spectrometry (MS/MS). The purity of the dopamine sulfates was estimated by HPLC using a diode array detector. We determined the enzyme kinetic parameters for formation of DA-3-O-sulfate and DA-4-O-sulfate using purified recombinant human SULT1A3. The reactions followed Michaelis-Menten kinetics up to 50 μM DA concentration, and strong substrate inhibition was observed at higher concentrations. The apparent K_m values for sulfonation at both hydroxy groups were similar (2.21 ± 0.764 and 2.59 ± 1.06 μM for DA-4-O-sulfate and DA-3-O-sulfate, respectively), but the V_max was approximately six times higher for the formation of the 3-O-sulfate (344 ± 139 nmol/min/mg protein) than the 4-O-sulfate (45.4 ± 16.5 nmol/min/mg protein). These results are in accordance with the observation that DA-3-O-sulfate is more abundant in human blood than DA-4-O-sulfate and that in the crystal structure of SULT1A3 with dopamine bound to the active site, the 3-hydroxy group is aligned to form hydrogen bonds with catalytic residues of the enzyme.     

Simultaneous quantitation of levodopa and 3-O-methyldopa in human plasma by HPLC-ESI-MS/MS: application for a pharmacokinetic study with a levodopa/benserazide formulation

A sensitive and simple method was developed for the quantitation of levodopa and its metabolite 3-O-methyldopa, in human plasma, after oral administration of tablet formulations containing levodopa (200 mg) and benserazide (50 mg). The analytes were extracted by a protein precipitation procedure, using carbidopa as an internal standard. A mobile phase consisting of 0.2% formic acid and acetonitrile (94:6, v/v) was used and chromatographic separation was achieved using ACE C₁₈ column (50 mm × 4.6 mm i.d.; 5 μm particle size). Selected reaction monitoring was performed using the fragmentation transitions m/z 198 → m/z 107, m/z 212 → m/z 166 and m/z 227 → m/z 181 for levodopa, 3-O-methyldopa and carbidopa, respectively. Calibration curves were constructed over the range 50.0-6000.0 ng/mL for levodopa and 25.0-4000.0 ng/mL for 3-O-methyldopa. The method shown to be specific, precise, accurate and provided recovery rates higher than 85% for all analytes. No matrix effect was detected in the samples. The validated method was applied in a pharmacokinetic study with a levodopa/benserazide tablet formulation in healthy volunteers.     

Generic systems for the enantioseparation of basic drugs in NACE using single-isomer anionic CDs

The enantioseparation of 10 basic drugs was evaluated in NACE systems using heptakis(2-O-methyl-3-O-acetyl-6-O-sulfo)-β-CD (HMAS-β-CD). For this purpose, a D-optimal design with 21 experimental points was applied. Four antifungal agents (econazole, isoconazole, miconazole, sulconazole), three local anesthetics (bupivacaine, mepivacaine and prilocaine), two sympathomimetics (salbutamol and terbutaline) and one β-blocker (carvedilol) were selected as basic model analytes. The influence on the enantiomeric resolution of anionic CD and BGE anion concentrations as well as the BGE anion nature was investigated. For all studied analytes, the enantiomeric resolution was shown to be significantly influenced by the CD concentration. Based on the observed results, a generic NACE system was recommended, namely 20 mM HMAS-β-CD and 10 mM ammonium camphorSO₃⁻ in methanol acidified with 0.75 M formic acid. Moreover, this NACE system was compared to previous conditions with heptakis(2,3-di-O-methyl-6-O-sulfo)-β-CD (HDMS-β-CD) or heptakis(2,3-di-O-acetyl-6-O-sulfo)-β-CD (HDAS-β-CD). Finally, two generic systems using either HDAS-β-CD or HMAS-β-CD were proposed and evaluated for the enantioseparation of ketamine and norketamine after incubation of ketamine in phenobarbital-induced male rat liver microsomes systems.     

Inhibitory effect of ethanol extract of Magnolia officinalis and 4-O-methylhonokiol on memory impairment and neuronal toxicity induced by beta-amyloid

The components of the herb Magnolia officinalis have exhibited antioxidant and neuroprotective activities. In this study, we investigated effects of ethanol extract of M.officinalis and its major component 4-O-methylhonokiol on memory dysfunction and neuronal cell damages caused by Aβ. Oral pretreatment of ethanol extract of M. officinalis (2.5, 5 and 10 mg/kg) and 4-O-methylhonokiol (1 mg/kg) into drinking water for 5 weeks suppressed the intraventricular treatment of Aβ_1-42 (0.5 μg/mouse, i.c.v.)-induced memory impairments. In addition, 4-O-methylhonokiol prevented the Aβ_1-42-induced apoptotic cell death as well as β-secretase expression. 4-O-methylhonokiol also inhibited H₂O₂ and Aβ_1-42-induced neurotoxicity in cultured neurons as well as PC12 cells by prevention of the reactive oxygen species generation. 4-O-methylhonokiol also directly inhibited β-secretase activity and Aβ fibrilization in vitro. Thus, ethanol extract of M. officinalis may be useful for prevention of the development or progression of AD, and 4-O-methylhonokiol may be a major active component.     

Electrophysiologic characterization of a novel hERG channel activator

Activators of the human ether-a-go-go-related gene (hERG) K⁺ channel have been reported recently to enhance hERG current amplitude (five synthetic small molecules and one naturally occurring substance). Here, we characterize the effects of a novel compound A-935142 ({4-[4-(5-trifluoromethyl-1H-pyrazol-3-yl)-phenyl]-cyclohexyl}-acetic acid) on guinea-pig atrial and canine ventricular action potentials (microelectrode techniques) and hERG channels expressed in HEK-293 cells (whole-cell patch clamp techniques). A-935142 shortened cardiac action potentials and enhanced the amplitude of the hERG current in a concentration- and voltage-dependent manner. The fully activated current-voltage relationship revealed that this compound (60 μM) increased both outward and inward K⁺ current as well as the slope conductance of the linear portion of the fully activated I-V relation. A-935142 significantly reduced the time constants (τ) of hERG channel activation at two example voltages (−10 mV: τ = 100 ± 17 ms vs. 164 ± 24 ms, n = 6, P < 0.01; +30 mV: τ = 16.7 ± 1.8 ms vs. 18.9 ± 1.8 ms, n = 5, P < 0.05) and shifted the voltage-dependence for hERG activation in the hyperpolarizing direction by 9 mV. The time course of hERG channel deactivation was slowed at multiple potentials (−120 to −70 mV). A-935142 also reduced the rate of inactivation and shifted the voltage-dependence of inactivation in the depolarizing direction by 15 mV. Recovery of hERG channel from inactivation was not affected by A-935142. In conclusion, A-935142 enhances hERG current in a complex manner by facilitation of activation, reduction of inactivation, and slowing of deactivation, and abbreviates atrial and ventricular repolarization.     

Biological potentials and cytotoxicity of various extracts from endemic Origanum minutiflorum O. Schwarz & P.H. Davis

The aim of the present study was to investigate antioxidative, antimicrobial and cytotoxic effects of endemic Origanum minutiflorum (O. Schwarz & P.H. Davis). Antioxidant activities of the extracts from O. minutiflorum were evaluated by using DPPH radical scavenging, β-carotene bleaching and metal chelating activity assays. In addition, the amounts of total phenol components in the plant extracts were determined. In the β-carotene bleaching test, the extracts exhibited in the range of 58.1 ± 0.2% – 98.2 ± 0.3% inhibition against linoleic acid oxidation. The antimicrobial efficiency of the plant was evaluated according to agar well diffusion and microdilution broth methods. The n-hexane extract of O. minutiflorum having an inhibition zone of 20.2 ± 0.2 mm, had the maximum antibacterial efficiency against Shigella sonnei RSKK 878. Cytotoxic effects of the extracts were determined by MTT assay. O. minutiflorum extracts (at concentration of 10–100 μg/ml) did not show any cytotoxic effect on baby hamster kidney fibroblast cell line. The results showed that O. minutiflorum could be used as a natural source in food industry.     

The Role of Intestinal Microflora in Anti-Inflammatory Effect of Baicalin in Mice

Baicalin, a main constituent of the rhizome of Scutellaria baicalensis, is metabolized to baicalein and oroxylin A in the intestine before its absorption. To understand the role of intestinal microflora in the pharmacological activities of baicalin, we investigated its anti-inflammatory effect in mice treated with and without antibiotics. Orally administered baicalin showed the anti-inflammatory effect in mice than intraperitoneally treated one, apart from intraperitoneally administered its metabolites, baicalein and oroxylin A, which potently inhibited LPS-induced inflammation. Of these metabolites, oroxylin A showed more potent anti-inflammatory effect. However, treatment with the mixture of cefadroxil, oxytetracycline and erythromycin (COE) significantly attenuated the anti-inflammatory effect of orally administered baicalin in mice. Treatment with COE also reduced intestinal bacterial fecal β-glucuronidase activity. The metabolic activity of human stools is significantly different between individuals, but neither between ages nor between male and female. Baicalin was metabolized to baicalein and oroxylin A, with metabolic activities of 1.427 ± 0.818 and 1.025 ± 0.603 pmol/min/mg wet weight, respectively. Baicalin and its metabolites also inhibited the expression of pro-inflammatory cytokines, TNF-α and IL-1β, and the activation of NF-κB in LPS-stimulated peritoneal macrophages. Of them, oroxylin A showed the most potent inhibition. Based on these findings, baicalin may be metabolized to baicalein and oroxylin A by intestinal microflora, which enhance its anti-inflammatory effect by inhibiting NF-κB activation.     

Simultaneous determination of 11 active components in two well-known traditional Chinese medicines by HPLC coupled with diode array detection for quality control

A simple and sensitive high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) method was investigated for simultaneous determination of 11 components (chlorogenic acid, coptisine, epiberberine, jatrorrhizine, berberine, palmatine, baicalin, wogonoside, baicalein, wogonin and chrysin) in Qinhuanghouzheng (QHHZ) capsule and Xiaoerqingre (XEQR) tablet, for quality control of these two well-known traditional Chinese medicines (TCMs). The method was established using an Eclipse Plus C₁₈ (150 mm × 4.6 mm i.d., 5 μm) column. The mobile phase comprising methanol (A) 3% phosphoric acid (B) (pH 2.0, adjusted by triethylamine) was used to elute the targets in gradient elution mode. Flow rate and detection wavelength were set at 0.8 mL/min and 270 nm, respectively. All calibration curves showed good linearity with R² > 0.9995. Inter- and intra-day precisions for all investigated components expressed as relative standard deviation (R.S.D.) ranged from 0.26% to 1.77%. Recoveries measured at three concentrations were in the range of 95.0–103.0% with R.S.D. ≤ 3%. The validated method is simple, reliable, and successfully applied to determine the contents of the selected compounds in QHHZ capsule and XEQR tablet for quality evaluation and control. The 11 main active marker compounds measured occur only in 2 or 3 plant species out of 7–10 species comprising the two TCMs. Additional procedures need to be developed for the quality control of plant materials other than Coptis chinensis Franch, Scutellaria baicalensis Georgi and Phellodendron amurense Rupr.     

Inhibitory activity of quercetin and its metabolite on lipopolysaccharide-induced activation of macrophage U937 cells

The potential of quercetin and its metabolite 3-O-methyl quercetin in inhibiting lipopolysaccharide (LPS)-mediated activation of macrophage U937 cells was investigated. Cells were pre-incubated for different periods with 100 ng/mL phorbol myristate acetate (PMA), and later with LPS and quercetin or 3-O-methyl quercetin (30 μM). Later, the supernatant of each cell culture was assessed for catalase activity, nitric oxide, and the production of tumour necrosis factor-α (TNF-α), interleukin 6 (IL-6), and interleukin 1 (IL-1). The results showed that when the cells were incubated with LPS, there were elevations in the levels of all the markers over the cells not incubated with LPS (P < 0.05). For the cells that were incubated with LPS, there were significant differences between the various cells when they were pre-incubated with PMA for various periods (P < 0.05). However, greatest production of the markers was attained when the cells were pre-treated with PMA for 48 h. Both quercetin and 3-O-methyl quercetin (at 30 mM) reduced the levels of all the markers with 3-O-methyl quercetin possessing more inhibitory potential (P < 0.05). This suggests that the flavonoids possessed significant immunomodulatory activities which depend on methylation especially at position 3.     

Anti-pruritic effect of baicalin and its metabolites, baicalein and oroxylin A, in mice Anti-tumorPharmacology

Aim:

To explore whether intestinal microflora plays a role in anti-pruritic activity of baicalin, a main constituent of the rhizome of Scutellaria baicalensis (SB).

Methods:

Baicalin was anaerobically incubated with human fecal microflora, and its metabolites, baicalein and oroxylin A, were isolated. The inhibitory effect of baicalin and its metabolites was accessed in histamine- or compound 48/80-induced scratching behavior in mice.

Results:

Baicalin was metabolized to baicalein and oroxylin A, with metabolic activities of 40.2±26.2 and 1.2±1.1 nmol·h⁻¹·mg⁻¹ wet weight of human fecal microflora, respectively. Baicalin (20, 50 mg/kg) showed more potent inhibitory effect on histamine-induced scratching behavior when orally administered than intraperitoneally. In contrast, baicalein and oroxylin A had more potent inhibitory effect when the intraperitoneally administered. The anti-scratching behavior activity of oral baicalin and its metabolites was in proportion to their inhibition on histamine-induced increase of vascular permeability with oroxylin A more potent than baicalein and baicalin. In Magnus test using guinea pig ileum, oroxylin A is more potent than baicalein and baicalin in inhibition of histamine-induced contraction. The anti-scratching behavioral effect of oral baicalin was significantly reduced when oral antibiotics were simultaneously administered, whereas the effect of baicalein and oroxylin A were not affected.

Conclusion:

Oral baicalin may be metabolized by intestinal microflora into baicalein and oroxylin A, which ameliorate pruritic reactions through anti-histamine action.     

Metabolism of the masked mycotoxin deoxynivalenol-3-glucoside in pigs

Plants can metabolize the Fusarium mycotoxin deoxynivalenol (DON) by forming the masked mycotoxin deoxynivalenol-3-β-d-glucoside (D3G). D3G might be cleaved during digestion, thus increasing the total DON burden of an individual. Due to a lack of invivo data, D3G has not been included in the various regulatory limits established for DON so far. The aim of our study was to contribute to the risk assessment of D3G by determination of its metabolism in pigs. Four piglets received water, D3G (116 μg/kg b.w.) and the equimolar amount of DON (75 μg/kg b.w.) by gavage on day 1, 5 and 9 of the experiment, respectively. Additionally, 15.5 μg D3G/kg b.w. were administered intravenously on day 13. Urine and feces were collected for 24 h and analyzed for DON, D3G, deoxynivalenol-3-glucuronide (DON-3-GlcA), deoxynivalenol-15-GlcA (DON-15-GlcA) and deepoxy-deoxynivalenol (DOM-1) by UHPLC–MS/MS. After oral application of DON and D3G, in total 84.8 ± 9.7% and 40.3 ± 8.5% of the given dose were detected in urine, respectively. The majority of orally administered D3G was excreted in form of DON, DON-15-GlcA, DOM-1 and DON-3-GlcA, while urinary D3G accounted for only 2.6 ± 1.4%. In feces, just trace amounts of metabolites were found. Intravenously administered D3G was almost exclusively excreted in unmetabolized form via urine. Data indicate that D3G is nearly completely hydrolyzed in the intestinal tract of pigs, while the toxin seems to be rather stable after systemic absorption. Compared to DON, the oral bioavailability of D3G and its metabolites seems to be reduced by a factor of up to 2, approximately.     

Simultaneous determination of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside from hawthorn leaves flavonoids in rat plasma by HPLC method and its application to pharmacokinetic studies

The present study was to investigate the pharmacokinetics of the two similar flavonoid glycosides, vitexin-4″-O-glucoside (VGL) and vitexin-2″-O-rhamnoside (VRH) in rats after intravenous administration of hawthorn leaves flavonoids (HLF). Blood samples were collected via tail vein at time intervals after drug administration and the plasma concentrations of the studied ingredients were analyzed by HPLC after the plasma protein was precipitated directly with methanol. VGL and VRH were successfully separated using a C₁₈ column with a UV detection at 330 nm and a mobile phase of methanol–acetonitrile–tetrahydrofuran–0.5% acetic acid (1:1:19.4:78.6, v/v/v/v). The assay linearities of VGL and VRH were confirmed over the range 0.23–138.42 and 0.36–218.49 μg/ml, respectively. The accuracy and precision of the two analytes at high, medium and low concentration were within the range of −3.13% to 3.51% and below 4%, the mean assay recoveries of them (n = 5) ranged from 96.87% to 101.75% and 96.88% to 103.51% for intra- and inter-day assays and the mean extraction recoveries of them (n = 5) varied from 92.68% to 95.74% for VGL and 93.45% to 99.26% for VRH, respectively. After intravenous administration of HLF to rats over the doses range of 10–40 mg/kg, the plasma concentration–time curves of VGL and VRH were both conformed to the three-compartment open pharmacokinetic model and linear pharmacokinetic characteristics.     

Effects of Thai Musa species on prevention of UVB-induced skin damage in mice

The effects of oral administration of Musa sapientum and Musa suerier on prevention of UVB induced skin damages were investigated in male ICR mice. Animals were orally administered 50 mg/day ascorbic acid, or M. sapientum or M. suerier’s fruit pulps at dose of 0.5, 1 or 1.5 mg/g body weight/day for 12 weeks. Concurrently, the shaved backs of animals were irradiated with UVB for 12 weeks. The intensity of irradiation was progressively increased, from 54 mJ/cm² per exposure at week 1–126 mJ/cm² at week 11. A significant decrease (p < 0.05) in skin elasticity (from 0.82 ± 0.02 to 0.42 ± 0.09) and total glutathione (from (193.6 ± 18.7 to 152.7 ± 7.8 ng/mg protein) as compared with the control group (water-administered UVB-irradiated mice) was observed after 12 weeks of UVB exposure. When l-ascorbic acid (0.72 ± 0.01) or 1 mg/g body weight/day M. suerier (0.84 ± 0.06) were administered to UVB-irradiated mice, the reduction in skin elasticity was significantly inhibited (p < 0.05). Moreover, the significant increase (p < 0.05) in level of total glutathione was found in these groups (220.8 ± 13.3 ng/mg protein for l-ascorbic acid and 224.9 ± 20.1 ng/mg protein for M. suerier). These findings suggest the potential effect of daily consumption of M. suerier on prevention of skin damage from repeated UVB exposure.     

Differential ion current activation by human 5-HT(1A) receptors in Xenopus oocytes: evidence for agonist-directed trafficking of receptor signalling

The subject of the present study was the functional and pharmacological characterization of human 5-HT_1A receptor regulation of ion channels in Xenopus oocytes. Activation of the heterologously expressed human 5-HT_1A receptor induced two distinct currents in Xenopus oocytes, consisting of a smooth inward current (I_smooth) and an oscillatory calcium-activated chloride current, I_Cl(Ca). 5-HT_1A receptor coupling to both ionic responses as well as to co-expressed inward rectifier potassium (GIRK) channels was pharmacologically characterized using 5-HT_1A receptor agonists. The relative order of efficacy for activation of GIRK current was 5-HT ≈ F13714 ≈ L694,247 ≈ LY228,729 > flesinoxan ≈ (±)8-OH-DPAT. In contrast, flesinoxan and (±)8-OH-DPAT typically failed to activate I_Cl(Ca). The other ligands behaved as full or partial agonists, exhibiting an efficacy rank order of 5-HT ≈ L694,247 > F13714 ≈ LY228,729. The pharmacological profile of I_smooth activation was completely distinct: flesinoxan and F13714 were inactive and rather exhibited an inhibition of this current. I_smooth was activated by the other agonists with an efficacy order of L694,247 > 5-HT ≈ LY228,729 > (±)8-OH-DPAT. Moreover, activation of I_smooth was not affected by application of pertussis toxin or the non-hydrolyzable GDP-analogue, guanosine-5′-O-(2-thio)-diphosphate (GDPβS), suggesting a GTP binding protein-independent pathway. Together, these results suggest the existence of distinct and agonist-specific signalling states of this receptor.     

Rapid resolution liquid chromatography (RRLC) analysis and studies on the stability of Shuang-Huang-Lian preparations

Shuang-Huang-Lian (SHL) is a traditional Chinese formula which comprises of three medicinal herbs: Flos Lonicerae, Radix Scutellariae and Fructus Forsythiae, and is commonly used to treat acute upper respiratory tract infection, acute bronchitis and light pneumonia. A simple, reliable and reproducible rapid resolution liquid chromatography (RRLC) method was developed for the quality control of SHL preparations, which baseline separates the major bioactive compounds within 6 min. The method uses a C18-HST column (2.5 μm, 100 mm × 3.0 mm) kept at 40 °C. The mobile phases consist of 0.1% phosphoric acid aqueous solution and acetonitrile. Flow rate is 1.0 ml/min and UV detection is performed at 327 nm from 0 to 4 min and 229 nm from 4 to 7 min. This method was further validated according to the ICH guidelines. Eight batches of commercial SHL preparations obtained from different pharmaceutical manufacturers as well as individual herbs were examined and their chromatographic profiles were compared. The stability test revealed that chlorogenic acid is stable only at acidic pH, and hence it is necessary to further evaluate and optimize the preparatory procedures and storage conditions for commercial SHL preparations.