Chalcone Scaffolds, Bioprecursors of Flavonoids: Chemistry, Bioactivities, and Pharmacokinetics

Chalcones are secondary metabolites belonging to the flavonoid (C6-C3-C6 system) family that are ubiquitous in edible and medicinal plants, and they are bioprecursors of plant flavonoids. Chalcones and their natural derivatives are important intermediates of the flavonoid biosynthetic pathway. Plants containing chalcones have been used in traditional medicines since antiquity. Chalcones are basically α,β-unsaturated ketones that exert great diversity in pharmacological activities such as antioxidant, anticancer, antimicrobial, antiviral, antitubercular, antiplasmodial, antileishmanial, immunosuppressive, anti-inflammatory, and so on. This review provides an insight into the chemistry, biosynthesis, and occurrence of chalcones from natural sources, particularly dietary and medicinal plants. Furthermore, the pharmacological, pharmacokinetics, and toxicological aspects of naturally occurring chalcone derivatives are also discussed herein. In view of having tremendous pharmacological potential, chalcone scaffolds/chalcone derivatives and bioflavonoids after subtle chemical modification could serve as a reliable platform for natural products-based drug discovery toward promising drug lead molecules/drug candidates.

Pharmacokinetics-based comprehensive strategy to identify multiple effective components in Huangqi decoction against liver fibrosis

BACKGROUND

Huangqi decoction (HQD) has been used to treat chronic liver diseases since the 11th century, but the effective components in HQD against liver fibrosis have not been definitively clarified.

PURPOSE

To investigate and identify multiple effective components in HQD against liver fibrosis using a pharmacokinetics-based comprehensive strategy.

METHODS

The absorbed representative components in HQD and their metabolites were detected in human plasma and urine using high-resolution mass spectrometry combined with a database-directed method, and then pharmacokinetics in multiple HQD components in human plasma was analyzed by ultra-performance liquid chromatography coupled with triple-quadruple mass spectrometry. Furthermore, the anti-fibrotic effect of potential effective HQD components was studied in LX-2 cells and that of a multi-component combination of HQD (MCHD) was verified in a mouse CCl4-induced hepatic fibrosis model.

RESULTS

Twenty-four prototype components in HQD and 17 metabolites were identified in humans, and the pharmacokinetic characteristics of 14 components were elucidated. Among these components, astragaloside IV, cycloastragenol, glycyrrhizic acid, glycyrrhetinic acid, liquiritigenin, and isoliquiritigenin downregulated the mRNA expression of α-SMA; cycloastragenol, calycosin-7-O-β-D-glucoside, formononetin, glycyrrhetinic acid, liquiritin, and isoliquiritin downregulated the mRNA expression of Col I; and calycosin, liquiritigenin, isoliquiritigenin, cycloastragenol, and glycyrrhetinic accelerated the apoptosis of LX-2 cells. MCHD reduced serum aminotransferase activity and hepatic collagen fibril deposition in mice with CCl4-induced hepatic fibrosis.

CONCLUSION

Using the pharmacokinetics-based comprehensive strategy, we revealed that multiple effective HQD components act together against liver fibrosis.

Synergistic Combination of Sodium Aescinate-Stabilized, Polymer-Free, Twin-Like Nanoparticles to Reverse Paclitaxel Resistance

BACKGROUND

The development of paclitaxel (PTX) resistance seriously restricts its clinical efficacy. An attractive option for combating resistance is inhibiting the expression of P-glycoprotein (P-gp) in tumor cells. We have reported that flavokawain A (FKA) inhibited P-gp protein expression in PTX-resistant A549 (A549/T) cells, indicating that FKA combined with PTX may reverse PTX resistance. However, due to the variable pharmacokinetics of FKA and PTX, the conventional cocktail combination in clinics may cause uncertainty of treatment efficacy in vivo.

MATERIALS AND METHODS

To synergistically elevate the anti-cancer activity of PTX and FKA in vivo, the national medical products administration (NMPA) approved sodium aescinate (Aes) was utilized to stabilize hydrophobic PTX and FKA to form polymer-free twin like PTX-A nanoparticles (NPs) and FKA-A NPs.

RESULTS

The resulting nanoparticles prepared simply by nanoprecipitation possessed similar particle size, good stability and ultrahigh drug loadings of up to 50%. With the aid of Aes, these two drugs accumulated in tumor tissue by passive targeting and were efficiently taken up by A549/T cells; this resulted in significant suppression of tumor growth in A549/T homograft mice at a low PTX dose (2.5 mg·kg-1). Synergistic effects and reversed PTX resistance were achieved by the combination of PTX-A NPs and FKA-A NPs by inhibiting P-gp expression in tumor cells.

CONCLUSION

Using NMPA-approved Aes to prepare twin-like nanoparticles without introducing any new materials provides an efficient platform for combination chemotherapy and clinical translation.

Pharmacokinetic Study on Protocatechuic Aldehyde and Hydroxysafflor Yellow A of Danhong Injection in Rats with Hyperlipidemia

BACKGROUND

Protocatechuic aldehyde (PAL) and hydroxysafflor yellow A (HSYA) are 2 effective ingredients of Danhong Injection, which is extensively used for the clinical treatment of cardio-cerebrovascular diseases. This study aims to investigate the pharmacokinetic differences between single and combined medication of PAL and HSYA and analyze the interaction of the above effective components in hyperlipidemia rats.

METHODS

Thirty male SD rats were randomly divided into the control group (n = 6) and the model group (n = 24). The hyperlipidemia model was established by feeding with superfatted forage. The successful model rats were then randomly divided into the PAL group (16 mg/kg), the HSYA group (10 mg/kg), and the combination group (16 mg/kg + 10 mg/kg). Administration through tail-vein, and orbital blood was sampled at different time points. The mass concentration of PAL and HSYA was determined by high performance liquid chromatography (HPLC-DAD). Analysis of pharmacokinetic parameters was conducted by using DAS 3.2.6 software and SPSS 19.0 statistical analysis software.

RESULTS

According to the parameters of statistical moment of non-compartmental model, there was a significant difference in plasma clearance (CL) between the PAL group and the drug combination group (p < 0.01), as well as in the area under the first moment of the plasma concentration-time curve and the elimination half-life (t1/2) between the HSYA group and the drug combination group (p < 0.01) but no obvious differences about the blood concentration time curve area, the average dwell time (MRT), and the peak concentration (Cmax; p > 0.05).

CONCLUSION

The combined medication of PAL and HSYA could increase the plasma CL significantly and have a great influence on the absorption of HSYA in rats with hyperlipidemia.

Pharmacokinetic profiles of hydroxysafflor yellow A following intravenous administration of its pure preparations in healthy Chinese volunteers

ETHNOPHARMACOLOGICAL RELEVANCE

Hydroxysafflor yellow A (HSYA), the major active marker compound isolated from Carthamus tinctorius L., has been demonstrated to possess various attractive pharmacological activities. However, there is a lack of information about the complete clinical pharmacokinetic profiles of HSYA following the administration of its pure preparations. The purpose of this study was to fully characterize the pharmacokinetic (PK) properties of HSYA in healthy Chinese volunteers following drip intravenous infusion of injectable powder of pure HSYA (IPPH), a new drug recently approved for the phase I clinical study by China Food and Drug Administration.

MATERIALS AND METHODS

36 healthy subjects of either sex were recruited in this single-center, and open-label, single doses (25, 50, and 75 mg) and multiple doses (50 mg, once daily, 7 consecutive days) study. Plasma samples were analyzed with a validated LC-MS/MS method. Various PK parameters were estimated from the plasma concentration versus time data using non-compartmental methods.

RESULTS

After single dose administration of IPPH, the values of AUC(0-t), AUC(0-∞) and C(max) for HSYA were statistically proportional over the dose range of 25-75 mg. After 7 repeated doses of 50 mg IPPH, both C(max) and AUC(0-∞) were significantly decreased, from 3207 to 2959 μg L(-1), and from 12,811 to 12,135 µg h L(-1) respectively, while t(1/2) was significantly prolonged from 3.912 to 4.414 h. The minimum plasma concentrations on day 5, 6 and 7 showed good stability with no significant difference. Both Cmax and AUC of HSYA in male volunteers were generally lower than that in females. IPPH was generally well tolerated in healthy volunteers by either single or multiple dosing.

CONCLUSION

HSYA displayed moderately linear PK properties over the doses ranging from 25 to 75 mg of IPPH. Repeated administration of IPPH once daily could not lead to the in-vivo drug accumulation, but significantly affect PK behavior of HSYA. Gender difference should be considered for dosage recommendation in the clinic.

[Studies on effects of Achyranthes bidentata on tongsaimai pellets main active ingredients chlorogenic acid, isoliquiritin, harpagoside and glycyrrhizin in vivo pharmacokinetics]

To study on the effects of Achyranthes bidentata on Tongsaimai pellets main active ingredients chlorogenic acid, isoliquiritin, harpagoside and glycyrrhizin in rats in vivo pharmacokinetic behaviors, a method for the simultaneous determination of chlorogenic acid, isoliquiritin, harpagoside and liquiritigenin in rat plasma was established by UPLC-MS/MS. The analysis was performed on a waters Acquity BEH C18 column (2.1 mm x 100 mm, 1.7 microm) with the mixture of acetonitrile and 0.1% formic acid/water as mobile phase, and the gradient elution at a flow rate of 0.3 mL x min(-1). The analytes were detected by tandem mass spectrometry with the electrospray ionization (ESI) source and in the multiple reaction monitoring (MRM) mode. It turned out that the analytes of Tongsaimai pellets groups C(max) and AUC(Q-infinity) values were higher than that with A. bidentata group, and the C(max) values of chlorogenic acid had significantly difference (P < 0.05), the AUC(0-infinity) values of chlorogenic acid and glycyrrhizin had significantly difference (P < 0.05); The T(max) and CL values of two groups had no significantly difference. Results showed that the established method was specific, rapid, accurate and sensitive for the studies of Tongsaimai pellets four main active ingredients in rat in vivo pharmacokinetic, and A. bidentata have varying degrees of effects on Tongsaimai pellets four main active ingredients in rat in vivo pharmacokinetic behaviors.

[Pharmacokinetic effect of Sappan Lignum on hydroxysafflor yellow A in Carthami Flos]

OBJECTIVE

To investigate the pharmacokinetic effect of Sappan Lignum on hydroxysafflor yellow A (HSYA) in Carthami Flos.

METHOD

Concentration of HSYA in rat plasma was detected by RP-HPLC after rats were orally administered with extracts of Carthami Flos or Carthami Flos combined with Sappan Lignum. Pharmacokinetic parameters were calculated by DAS 2.0 pharmacokinetic software.

RESULT

In vivo pharmacokinetic models of HSYA were two-compartment open models in both of the Carthami Flos group and the Carthami Flos combined with Sappan Lignum group. After compatibility, HSYA showed a significant lower in apparent volumes of distribution of t(1/2Ka), t(1/2alpha) and V1/F, with slight advance in T(max).

CONCLUSION

Sappan Lignum can accelerate absorption, distribution and metabolic process of HSYA in vivo and reduce its accumulation in vivo.

[Studies on pharmacokinetics of hydroxysafflor yellow A in Carthamus tinctorius and its compound preparation in rat]

OBJECTIVE

To develop a RP-HPLC method for the determination of the concentration of hydroxysafflor yellow A in rat plasma, to study the pharmacokinetics of Carthamus tinctorius extration and Naodesheng tablet, and to investigate the effect of other components on the pharmacokinetics of hydroxysafflor yellow A.

METHOD

The rats were orally treated with Carthamus tinctorius extration and Naodesheng capsule respectively. Blood samples were collected in heparinized eppendorf tube via the oculi chorioideae vein. Plasma was separated by centrifugation at 10 000 r x min(-1) for 10 min, and two-times methanol in volume was added to deposit proteins. After centrifugation, the upper liquid was transferred to filter. The concentration of hydroxysafflor yellow A in serum was determined by RP-HPLC. The stationary phase was C18, and methanol-acetonitrile-0.7% orthophosphoric acid (26: 2:72) was taken as the mobile phase, A UV detector was used at 403 nm. The pharmacokinetic parameters were calculated with 3p97 program.

RESULT

A good linear relationship of hydroxysafflor yellow A was obtained in the range of 0.03 and 2.56 mg x L(-1), the lowest limit of determination was 10 microg x L(-1), and the lowest limit of quantitation was 30 microg x L(-1). The mean recoveries were (99.3 +/- 1.4)%, (92.8 +/- 1.8)%, (98.4 +/- 2.0)% for high, middle, low concentrations of the samples respectively. The plasma concentration-time curves of hydroxysafflor yellow A were fitted with two-compartments model. The AUC)0-t), AUC(0-infinity), C(max) and T(max) of hydroxysafflor yellow A were increased in the Naodesheng group, compared with 50 mg x kg(-1) C. tinctorius extract group.

CONCLUSION

The HPLC method was selective, accurate and sensitive. The results indicated that the other herbs improved the absorption of hydroxysafflor yellow A and increased the bioavailability of hydroxysafflor yellow A significantly.

Diphenylpropynone derivatives as probes for imaging β-amyloid plaques in Alzheimer's brains

A new series of diphenylpropynone (DPP) derivatives for use in vivo to image β-amyloid (Aβ) plaques in the brain of patients with Alzheimer's disease (AD) were synthesized and characterized. Binding experiments in vitro revealed high affinity for Aβ (1-42) aggregates at a K(i) value ranging from 6 to 326 nM. Furthermore, specific labeling of plaques was observed in sections of brain tissue from Tg2576 transgenic mice stained using one of the compounds, 1. In biodistribution experiments with normal mice, [(125)I]1 displayed moderate uptake (1.55%ID/g at 2 min) and clearance from the brain with time (0.76 ID/g at 60 min). Taken together, DPP can serve as a new molecular scaffold for developing novel Aβ imaging agents by introducing appropriate substituted groups.

Pharmacokinetic comparisons of hydroxysafflower yellow A in normal and blood stasis syndrome rats

ETHNOPHARMACOLOGICAL RELEVANCE

Safflower is a popular Traditional Chinese Medicine (TCM) to invigorate the blood and dispel 'blood stasis', which arises from poor blood circulation. The differences of pharmacokinetic properties between normal and blood stasis syndrome rats were seldom reported.

AIM OF THE STUDY

The present study was conducted to evaluate the pharmacokinetics of hydroxysafflower yellow A (HSYA) following oral administration of hydroxysafflower yellow A and safflower extract with approximately the same dose of HSYA 100mg/kg in both normal and acute blood stasis rats.

MATERIALS AND METHODS

The animals were orally administered with HYSA monomer and safflower extract. The blood samples were collected according to the time schedule. The concentrations of HSYA in rat plasma were determined by HPLC. Various pharmacokinetic parameters were estimated from the plasma concentration versus time data using non-compartmental methods.

RESULTS

It was found that AUC(0-t), C(max), Vd and CL of HSYA in both HSYA monomer and safflower extract in acute blood stasis rats were with significant difference (P<0.05) comparing with that in normal rats.

CONCLUSIONS

The results indicated that HSYA was with high uptake and eliminated slowly in the animals with blood stasis syndrome, suggesting that the rate and extent of drug metabolism was altered in acute blood stasis animals.

The mechanisms for enhanced oral absorption of hydroxysafflor yellow A by chuanxiong volatile oil

The aims of this study were to investigate the effect of ligusticum chuanxiong volatile oil (CVO) on the oral absorption of hydroxysafflor yellow A (HSYA). The effects were studied both IN VITRO and IN VIVO. The contents of CVO were measured by GC-MS. The Caco-2 cell model was used to evaluate HSYA permeation with or without the presence of CVO. Transepithelial electrical resistance (TEER) of the Caco-2 cell monolayers was monitored and the alteration in the subcellular localization of claudin-1, the tight junction protein, was observed by immunofluorescence. The irritation of CVO on rat intestine was studied by paraffin slice technology. Our results demonstrated that CVO mainly contained ligustilide (47.82 %). The Papp of HSYA was improved by 5.34-fold and 4.62-fold in the presence of 0.02 mg/mL and 0.01 mg/mL of CVO, respectively. After opening of the tight junctions of the Caco-2 cell monolayer, TEER decreased, the position of claudin-1 changed, and its expression increased. CVO at different concentrations (10, 25, 100 and 200 mg/kg) caused no significant irritation on rat intestine. The bioavailability of HSYA in rats was increased by 6.48-fold and 4.91-fold when 100 and 25 mg/kg of CVO were co-administrated, respectively. CVO was an effective absorption enhancer for oral delivery of BCS III drugs. It can cause redistribution of claudin-1 proteins and open the tight junctions.

Pharmacokinetic properties of hydroxysafflor yellow A in healthy Chinese female volunteers

ETHNOPHARMACOLOGICAL RELEVANCE

Hydroxysafflor yellow A (HSYA) was isolated from the dried flower of Carthamus tinctorius L. which was extensively used in traditional Chinese medicine to treat diseases due to blood stasis. However, there have been few detailed pharmacokinetic studies about HSYA on human beings.

AIM OF THE STUDY

The aim was to investigate the pharmacokinetic characteristics of HSYA in healthy Chinese female volunteers.

MATERIALS AND METHODS

The volunteers were given intravenous infusion of single doses of safflor yellow injection (containing HSYA 35, 70 and 140 mg) in separate trial periods with 1 week washout period. The concentration levels of HSYA in plasma were determined with HPLC. Various pharmacokinetic parameters were estimated from the plasma concentration versus time data using non-compartmental methods.

RESULTS

The C(max) values were 2.02+/-0.18, 7.47+/-0.67 and 14.48+/-4.71 microg/mL after the administration of single doses of 35, 70, and 140 mg of HSYA, respectively. The corresponding values of AUC(0-15 h) were 6.57+/-1.20, 25.90+/-4.62 and 48.47+/-12.11 microg/(mL h(-1)), and the values of t(1/2) were 3.21+/-1.26, 3.33+/-0.68 and 2.98+/-0.09 h. The Student-Newman-Keuls test results showed that C(max) and AUC(0-15 h) were both linearly related to dose.

CONCLUSIONS

In this study, the pharmacokinetic properties of HSYA are based on first-order kinetics over the dose range tested.

HPLC determination of safflor yellow A and three active isoflavones from TCM Naodesheng in rat plasma and tissues and its application to pharmacokinetic studies

A high-performance liquid chromatographic method was developed for the simultaneous determination and pharmacokinetic studies of safflor yellow A, puerarin, 3'-methoxyl-puerarin, and puerarinapioside in the plasma and tissues of rats that had been administered with the traditional Chinese medicine (TCM) preparation Naodesheng via the caudal vein. Samples taken from rats were subjected to protein precipitation with acetone. Separation of these four compounds was accomplished on a Kromisil C18 stationary phase using a mobile phase of acetonitrile-0.1% phosphoric acid-tetrahydrofuran (8:92:2, v/v/v) at a flow-rate of 1.0 mL/min. The detection wavelength was set at 250 nm. The calibration curves of the four components were linear in the given concentration ranges. The intra- and inter-day precisions in plasma and tissues were less than 15% and the extraction recoveries were higher than 60%. The lower limits of quantitation of four components were low enough to determine the four components. These four components all exhibited kinetics that fitted a two-compartment model in rats. The elimination half-life was 1.19 h for safflor yellow A, 2.69 h for puerarin, 2.94 h for 3'-methoxyl-puerarin, and 0.87 h for puerarinapioside, respectively. Following administration of a single injection of Naodesheng, the concentration (C) of the four components in the tissues showed C(kidney) > C(lung), C(liver) > C(spleen), C(stomach), C(heart), approximately. The method is a reliable tool for performing studies of safflor yellow A and three puerarin isoflavones in different biological material.

Pharmacokinetics and excretion of hydroxysafflor yellow A, a potent neuroprotective agent from safflower, in rats and dogs

Studies were conducted to characterize the pharmacokinetics and excretion of hydroxysafflor yellow A (HSYA) in rats and dogs after administration by intravenous injection or infusion. Plasma, urine, feces and bile concentrations of HSYA were measured using five validated mild HPLC methods. Linear pharmacokinetics of HSYA after the intravenous administrations were found at doses ranging from 3 to 24 mg/kg in rats and from 6 to 24 mg/kg in dogs. At a dose of 3 mg/kg, HSYA in urine, feces and bile was determined. For 48 h after dosing, the amount of urinary excretion accounted for 52.6 +/- 17.9 % (range: 31.1 - 78.7%, n = 6) of the dose, and the amount of fecal amount accounted for 8.4 +/- 5.3% (range 1.7 - 16.4%, n = 6) of the dose. Biliary excretion amount accounted for 1.4 +/- 1.0% (range 0.4-2.9%; n = 6) of the dose for 24 h after dosing. Percent plasma protein binding of HSYA ranged from 48.0 to 54.6% at 72 h. In summary, five mild HPLC methods for the determinations of HSYA in rat plasma, urine, feces, bile and dog plasma have been developed and successfully applied to preclinical pharmacokinetics and excretion of HSYA in rats and dogs. The results of excretion studies indicated that HSYA was rapidly excreted as unchanged drug in the urine. In view of previous pharmacological work, the concentration-dependent neuroprotective effect of HSYA in rats was defined.

[Study on distribution of safflor yellow A in tissues of mice]

AIM

To study the distributive character of safflor yellow A in mice.

METHODS

A RP-HPLC method for the determination of safflor yellow A in tissues was established and applied to determine safflor yellow A in biological samples.

RESULTS

After iv injection of Safflor yellow A in mice, the AUC of safflor yellow A was hightest in plasma, followed by kidney, liver, lung, heart, spleen. But it was not found in the brain.

CONCLUSION

The distribution of safflor yellow A in the body is abroad and the speed of its process is swift.

[Pharmacokinetical study of safflor yellow on rat acute model of blood stasis syndrome]

OBJECTIVE

To study the pharmacokinetical character of safflor yellow in rat acute model of blood stasis syndrome.

METHODS

The rat acute model of blood stasis syndrome was made by i.p. adrenalin (0.07 ml/kg) and the stimulation of ice-water. At the time of 5, 10, 30, 60, 120, 180, 320, 480 min, the concentration of safflor yellow in the serum after i.v. safflor yellow (37.08 ml/kg) was determined.

RESULTS

The concentration-time date of safflor yellow in rat acute model of blood stasis syndrome was shown to fit a double-compartment open model, t1/2 alpha = 1.43 min, t1/2 beta = 95.65 min, AUC = 49,632.90 micrograms.min/ml; while the concentration-time data of safflor yellow in normal rat was shown to fit a single-compartment open model, t1/2 alpha = 66.27 min, AUC = 42,267 micrograms.min/ml.

CONCLUSION

The metabolism of safflor yellow was evidently later in rat acute model of blood stasis syndrome than in normal rat.

Influence of the level of cytosolic epoxide hydrolase on the induction of sister chromatid exchanges by trans-beta-ethylstyrene 7,8-oxide in human lymphocytes

trans-beta-Ethylstyrene 7,8-oxide, a substrate of cytosolic epoxide hydrolase, and 4-fluorochalcone oxide, an inhibitor of this enzyme, were investigated on induction of sister chromatid exchanges (SCE) in human lymphocytes. Both epoxides enhanced the frequency of SCE. 4-Fluorochalcone oxide at low concentration (2.5 microM) inhibited cytosolic epoxide hydrolase activity towards trans-beta-ethylstyrene 7,8-oxide in lymphocytes by 74% and had no effect on glutathione transferase activity using this substrate. At this concentration it did not induce SCE itself, but it potentiated the effect of trans-beta-ethylstyrene 7,8-oxide several fold. In lymphocytes from different subjects, the number of SCE induced by a low concentration of trans-beta-ethylstyrene 7,8-oxide correlated negatively with the individual cytosolic epoxide hydrolase activity (r = -0.72; -0.73 in two series of experiments). The number of SCE induced by a high concentration of trans-beta-ethylstyrene 7,8-oxide did not correlate with cytosolic epoxide hydrolase activity (r = 0.004; -0.24), but a negative correlation was found with glutathione transferase activity (r = -0.50). This finding is consistent with the results of biochemical studies in lymphocytes in which we determined the relative contribution of cytosolic epoxide hydrolase and glutathione transferase to the metabolism of trans-beta-ethylstyrene 7,8-oxide at varying substrate concentrations. The study demonstrates that the level of genotoxic effects induced in human lymphocytes is influenced by the individual level of detoxifying enzymes. At low concentrations, cytosolic epoxide hydrolase was more important than glutathione transferase activity.