醒脑静口服制剂中冰片在脑缺血及假手术大鼠脑组织和血浆中药物动力学研究

为了研究醒脑静中冰片在脑中风病理状态脑和血中的药动学特征,并评价脑中风对冰片透过血脑屏障能力的影响。该实验采用大脑中动脉线栓再灌注法建立并选取脑中风模型大鼠,并设立假手术组,灌胃给予醒脑静混悬液,不同时间点采血后进行GC测定,以Kinetica 软件拟合,计算相关药动学参数。 结果表明在脑中风状态下的脑、血的C_max为(1.82±0.825),(1.35±0.43) mg·L^-1,AUC_0-t为(123.39±55.82),(87.91±39.81) mg·L^-1·min,T_e (脑/血药物比) (71.3±3.24)%,大于假手术组的各个参数。从结果中可以看出脑中风的发生能够促进醒脑静中冰片透过血脑屏障,增加冰片的入脑量,为冰片的合理使用以及醒脑静口服制剂的研究提供了参考。     

An LC/MS/MS method for simultaneous quantitation of two homoisoflavones: Protosappanin B and brazilin with hypoglycemic activity in rat plasma and its application to a comparative pharmacokinetic study in normal and streptozotocin-treated rats

Ethnopharmacological relevance

The heartwood of Caesalpinia sappan L. (Leguminosae), a widely used Chinese medicine in folk, has been used for the treatment of traumatic injury, stasis pain, amenorrhea, dysmenorrheal, as well as stabbing pain in the chest, abdomen and so on. Protosappanin B and brazilin, as the major bioactive homoisoflavones of Sappan Lignum, are used as the marker components for the quality control of the herb in China Pharmacopoeia.

Aim of the study

To establish a sensitive LC/MS/MS method for investigating the pharmacokinetic properties of protosappanin B and brazilin in rats after oral administration of Sappan Lignum extract, and compare their pharmacokinetics difference between normal and streptozotocin-treated rats.

Material and methods

A rapid, selective and sensitive LC/MS/MS method was developed and validated for the simultaneous quantification of protosappanin B and brazilin in rat plasma. Normal and streptozotocin-treated rats were orally administered with the Sappan Lignum extract at the same dose of 2.83 g extract/kg body weight (equivalent to 35.56 mg/kg of protosappanin B and 52.25 mg/kg of brazilin), respectively.

Results

After oral administration of Sappan Lignum extract, a remarkable increase (p<0.05) in the value of AUC_0–24 h, AUC_0–∞, C_max and T_1/2 associated with protosappanin B and brazilin was observed in the streptozotocin-treated group. Compared with the normal rats, elimination of both compounds in the streptozotocin-treated rats was slower.

Conclusion

The established method was successfully applied to compare the pharmacokinetic behaviors of protosappanin B and brazilin in rat plasma after oral administration of Sappan Lignum extract between normal and streptozotocin-treated groups; the results might suggest the accumulation of both compounds in diabetic pathologic states and the adverse reaction should be considered when it was used.     

A simple high-performance liquid chromatographic method for the determination of brazilin and its application to a pharmacokinetic study in rats

Ethnopharmacological relevance

Caesalpinia sappan is a medicinal plant native to China popularly used to treat chronic pelvic inflammation, dysmenorrhea and hysteromyoma. Its main bioactive component is brazilin which had presented antibacterial, anti-inflammatory and anti-platelet aggregation activities. To establish a sensitive, selective, reproducible, and accurate high performance liquid chromatographic (HPLC) method for the quantitative determination of brazilin in plasma, and study the pharmacokinetics of brazilin in rats after intravenous administration of brazilin.

Materials and methods

Rats received intravenous injection of 25, 50 and 100 mg/kg of brazilin. Concentrations of brazilin in plasma were determined by HPLC method at different time points and all pharmacokinetic parameters were estimated by non-compartmental analysis with WinNonLin 6.2 software.

Results

After single intravenous doses of 25, 50 and 100 mg/kg brazilin in rats, the main PK parameters were as follows: C_max were 18.1±4.1, 46.7±8.7 and 82.2±9.6 µg/mL; AUC_0–24 were 20.4±4.3, 48.7±6.8 and 90.4±10.3 µg h/mL; and t_1/2 were 5.4±1.5, 5.8±0.9 and 6.2±1.2 h, respectively.

Conclusion

It showed that the brazilin was eliminated moderately in rat by intravenous injection route with t_1/2 of 6 h and showed a dose-dependence profile of C_max and AUC_0–24 at the doses of 25~100 mg/kg of brazilin for injection in rats.     

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 100 mg/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.     

Glycyrrhizin accelerates the metabolism of triptolide through induction of CYP3A in rats

Ethnopharmacological relevance

Triptolide (TP), a major active component of Tripterygium wilfordii, possesses various pharmacological activities with narrow therapeutic window and severe toxicities. Glycyrrhizin (GL), the principal bioactive ingredient of licorice root extract, has been reported to be concomitantly administered with TP in treatment of rheumatoid arthritis with the aim of potentiated efficacy and reduced toxicity. The aim of the study is to investigate the effect of GL on the pharmacokinetic profiles of TP and related mechanisms.

Materials and methods

Male and female Wistar rats were randomly divided into two groups: Control group and GL group (pretreated with GL at 100 mg/kg/day for seven consecutive days). After oral administration of TP at a single dose of 450 μg/kg, plasma concentrations of TP were determined using HPLC–MS/MS and pharmacokinetic parameters were calculated by non-compartmental analysis using Phoenix WinNonlin 6.3 software. Since CYP3A is the primary isoform of cytochrome P450s responsible for the metabolism of TP, we further determined to what extent ketoconazole (KCZ), a potent CYP3A inhibitor, could influence the effect of GL on the pharmacokinetics of TP by comparing the pharmacokinetic profiles of TP in GL group (pretreated with GL) and GL+KCZ group (pretreated with both GL and KCZ), as well as verified whether pretreatment of GL could induce the activity of hepatic CYP3A by comparing the AUC parameters after intravenous administration of midazolam (MDZ), a typical probe drug for CYP3A, in rats pretreated with vehicle or GL.

Results

Our study revealed marked differences in pharmacokinetic profiling patterns of TP between male and female rats in the Control group; the plasma level of TP in males was far lower than that in females. After pretreatment with GL, the pharmacokinetic profiles of TP were significantly altered in both male and female rats; a remarkable decrease was found in the value of AUC_∞, MRT_∞ and t_1/2 in the GL group, compared with the Control group. But such a decrease was reversed by KCZ; compared with the GL group, the values of AUC_∞, MRT_∞ and t_1/2 were significantly increased in the GL+KCZ group. Pretreatment with GL notably increased the AUC_∞ of 1?-hydroxymidazolam (OH-MDZ) and the ratio of AUC_∞ of OH-MDZ to MDZ, demonstrating induction of the activity of CYP3A by GL.

Conclusion

Pretreatment with GL significantly accelerates the metabolic elimination of TP from the body mainly through induction of hepatic CYP3A activity. These results may help explain why toxicity of TP may be attenuated with concomitant use of GL.     

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 μg/mL after the administration of single doses of 35, 70, and 140 mg of HSYA, respectively. The corresponding values of AUC_0–15h were 6.57 ± 1.20, 25.90 ± 4.62 and 48.47 ± 12.11 μg/(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_0–15h 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.     

UPLC-MS/MS-ESI assay for simultaneous determination of magnolol and honokiol in rat plasma: Application to pharmacokinetic study after administration emulsion of the isomer

Ethnopharmacological relevance

Magnolia officinalis is one of the commonly used in traditional Chinese medicine for the treatment of fever, chronic bronchitis and stomach ailments. Magnolol and honokiol are isomers with hydroxylated biphenol compound in the extract of Magnolia officinalis. This study aims to determine the isomers in rat plasma and evaluate their pharmacokinetic pattern after administration emulsion.

Materials and methods

Sprague Dawley male rats received either an intravenous (i.v.25, mg/kg) or oral (50 mg/kg) dose of the emulsion of the isomer. A sensitive and specific ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed for the investigation of the pharmacokinetics of magnolol and honokiol in rats. Kaempferol was employed as an internal standard.

Results

The plasma samples were deproteinized with acetonitrile, the post-treatment samples were analyzed on an Agela C₁₈ column interfaced with a triple quadrupole tandem mass spectrometer in negative electrospray ionization mode. Acetonitrile and 5 mmol/L ammonium acetate buffer solution (65: 35, v/v) was used as the mobile phase at a flow rate of 0.2 mL/min. Following oral administration of emulsion to rats, magnolol attained mean peak plasma concentrations of 426.4±273.8 ng/mL at 1.20 h, whereas honokiol reached peak plasma concentrations of 40.3±30.8 ng/mL at 0.45 h. The absolute bioavailability of magnolol and honokiol is 17.5±9.7% and 5.3±11.7%. By comparison, the AUC_0–∞ of magnolol was 5.4 times higher than that of honokiol after intravenous administration, but AUC_0–∞ of magnolol was about 18-fold higher than honokiol after oral administration.     

Gender-related pharmacokinetics and absolute bioavailability of diosbulbin B in rats determined by ultra-performance liquid chromatography-tandem mass spectrometry

Ethnopharmacological relevance

Diosbulbin B (DB) is the main constituent of furano-norditerpenes in Dioscorea bulbifera Linn., which is widely distributed in China and was usually used as a remedy for sore throat, struma and tumor. Owing to its potential antitumor activity, DB has been considered as a promising candidate for drug development.

Aim of the study

To study the pharmacokinetic properties and excretion of DB in rats by a sensitive UPLC–MS/MS method. Absolute bioavailability and gender-related pharmacokinetic properties, as well as excretion fractions of DB in urine and feces after oral and intravenous administrations would be addressed for the first time.

Materials and methods

Sprague–Dawley rats were administrated orally (32 mg/kg) and intravenously (0.5 mg/kg) of DB, respectively. The concentrations of DB in rat plasma were determined by a sensitive and well-validated LC–MS/MS method. Main pharmacokinetic parameters including area under the plasma concentration–time curve (AUC), elimination half time (t_1/2), mean residence time (MRT), apparent volume of distribution (V_d) and clearance rate (CL) were estimated using a non-compartmental pharmacokinetics data analysis software. Urine and feces of rats were collected within 48 h after oral administration (32 mg/kg) and detected by UPLC–MS/MS and HPLC, respectively.

Results

The standard curves of DB in rat plasma and urine showed good linearity in the concentration range of 1.0–515 ng/mL in the method, with acceptable selectivity, precisions, recoveries, and stability. The oral absolute bioavailability of DB in female rats was 2.0%, significantly higher than that of males (0.3%) (p<0.05). Female rats demonstrated longer t_1/2 and MRT (p<0.01), bigger V_d and higher CL (p<0.05) than males after intravenous administration of DB. Bigger but no significant difference in excretion fractions of urine and feces in female rats were observed, comparing to those in males.

Conclusion

A simple and sensitive UPLC–MS/MS method was developed to determine the pharmacokinetic profiles of DB in rats, as well as the excretion in rat urine. Gender exerted a significant influence on the pharmacokinetics and bioavailability of DB in rats. Female rats showed significantly better absorption of DB than males after oral administration.     

Interaction of five anthraquinones from rhubarb with human organic anion transporter 1 (SLC22A6) and 3 (SLC22A8) and drug–drug interaction in rats

Ethnopharmacological relevance

Rhubarb is a well-known traditional Chinese medicine and has been used in China for thousands of years. Anthraquinone derivatives including rhein, emodin, aloe-emodin, chrysophanol and physcion are the important components in rhubarb.

Materials and methods

Here we studied the interaction of five anthraquinone derivatives with human renal organic anion transporter 1 (hOAT1) and hOAT3 stably expressed in cells, and interaction of rhein or rhubarb extract (RE) with furosemide (FS, substrate of OATs) in rats.

Results

Uptake of 6-carboxyl fluorescein via hOAT1 and fluorescein via hOAT3 were markedly inhibited by rhein, emodin and aloe-emodin, and slightly inhibited by chrysophanol and physcion. The estimated IC₅₀ values for rhein, emodin, aloe-emodin and probenecid (typical inhibitor of hOAT1 and hOAT3) were 0.23, 0.61, 2.29 and 18.34 μM for hOAT1, and 0.08, 1.22, 5.37 and 5.83 μM for hOAT3, respectively. Furthermore, the data from the cellular accumulation assay indicated that these five compounds were not substrates of hOAT1 or hOAT3. Pharmacokinetic interaction between rhein and FS in rats showed that area under the curve (AUC_0–t) for FS was increased by 65% when coadministrated with rhein. RE was also used to interact with FS in rats and results showed that AUC_0–t of FS was increased by 32% and by 52% when coadministrated with single-dose or multiple-dose of RE, respectively.

Conclusions

These findings suggested that five anthraquinones inhibited hOAT1 and hOAT3, but these compounds were not transported by hOAT1 or hOAT3. Furthermore, rhein or RE, might cause drug–drug interaction when coadministrated with substrates of OAT1 or OAT3 in vivo.     

Comparative pharmacokinetics of swertiamarin in rats after oral administration of swertiamarin alone,Qing Ye Dan tablets and co-administration of swertiamarin and oleanolic acid

Ethnopharmacological relevance

Qing Ye Dan is a well-known herbal drug that is widely used to treat viral hepatitis in the Yi and Hani minority regions in the Yunnan province of China.

Materials and methods

An LC–MS/MS method was developed to determine the levels of swertiamarin in rat plasma. Swertiamarin and naringin (internal standard, IS) were extracted from rat plasma using solid-phase extraction (SPE) to purify the samples. The pharmacokinetics of the following different administration methods of swertiamarin in rats were studied: oral administration of swertiamarin alone, a Qing Ye Dan tablet (QYDT) and co-administration of swertiamarin and oleanolic acid, with each method delivering approximately 20 mg/kg of swertiamarin. Non-compartmental pharmacokinetic profiles were constructed by using the software DAS (version 2.1.1), and the pharmacokinetic parameters were compared using an unpaired Student's t-test.

Results

The results showed that the pharmacokinetic parameters C_max, AUC_0–∞, V_z/F and CL_z/F were significantly different (P<0.05) among the three types of swertiamarin administration.

Conclusions

The data indicate that oleanolic acid and the other ingredients present in QYDT could affect the pharmacokinetic behaviour of swertiamarin in rats.     

Pharmacokinetic comparisons of berberine and palmatine in normal and metabolic syndrome rats

Ethnopharmacological relevance

San-Huang formula is a popular traditional Chinese medicine (TCM) preparation to replenish Qi, resolve phlegm, dissipate blood stasis, and therapy metabolic syndrome in China. Metabolic syndrome, which is accompanied by Qi and blood stasis, mainly arises from spleen deficiency in essence. There is limited information available for differences of pharmacokinetic properties of San-Huang formula between normal and metabolic syndrome rats. The present study was conducted to compare the pharmacokinetics of berberine as well as palmatine in normal and metabolic syndrome rats following oral administration of San-Huang formula extract.

Materials and methods

The animals were orally administered with San-Huang formula extract with the equivalent dose of 60.4 and 12.5 mg/kg for berberine and palmatine, respectively. The blood samples were collected according to the time schedule. The concentrations of berberine and palmatine in rat plasma were determined by LC–ESI/MS. 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 berberine and palmatine in metabolic syndrome rats were significantly different (P<0.05) from normal rats.

Conclusions

The results indicated that berberine and palmatine have higher uptake and slower elimination in the rats with metabolic syndrome, which suggests that the rate and extent of drug metabolism were altered in metabolic syndrome rats.     

Gender-dependent pharmacokinetics of lignans in rats after single and multiple oral administration of Schisandra chinensis extract

Ethnopharmacological relevance

Schisandra chinensis (S. chinensis), a traditional Chinese medicine, has been widely used as sedatives and tonics in clinic. Schisandra lignans are believed to be the major bioactive components in S. chinensis. However, there is a lack of information about the effects of gender and repeated-dose on the pharmacokinetic properties of the schisandra lignans.

Aim of the study

The study was performed to investigate the influence of gender on the pharmacokinetics of schisandra lignans after administration of S. chinensis extract and to compare their pharmacokinetic behaviors between single and multiple administration.

Materials and methods

Two groups of rats (half male and half female) were received a single dose or multiple doses of S. chinensis extract, respectively. A liquid chromatography–tandem mass spectrometry method was developed and validated to determine the plasma concentrations of schisandra lignans.

Results

The pharmacokinetic parameters of schisandrin, schisandrol B, deoxyschisandrin, γ-schisandrin and schisantherin A were significantly different by gender difference. The t_1/2 of all the tested schisandra lignans in female rats were 2–9 times longer than the corresponding values in male rats. The C_max and AUC_0−t of these schisandra lignans except schisantherin A in female rats were 5–50 times higher than those in male rats. The pharmacokinetic profiles of schisandrin, schisandrol B, deoxyschisandrin and schisantherin A in both gender rats after multiple doses were similar to the corresponding profile after single dose.

Conclusion

All the tested schisandra lignans showed slower elimination and higher bioavailability in female rats after single or multiple administration of S. chinensis extract compared with male rats. Their pharmacokinetic profiles were not affected by repeated-dose except γ-schisandrin, which was eliminated more slowly in female rats after multiple administration.     

醒脑静中各成分对栀子提取物中栀子苷大鼠鼻腔吸收的影响

目的:研究醒脑静中冰片(天然或人工)、人工麝香及合方后对栀子提取物大鼠鼻腔吸收的影响.方法:以体积校正法,采用改良的大鼠在体鼻灌流模型,研究与不同成分配伍后栀子苷的大鼠鼻腔吸收情况.结果:质量浓度为100,250,1 000 mg·L-1的栀子提取物溶液(分别含栀子苷36.8,92,368 mg·L-1)中栀子苷吸收速率常数K分别为(2.15±0.70)×10-3,(1.97±0.48) ×10-3,(1.87±0.81) ×10-3min-1,栀子苷的鼻腔吸收符合一级速率过程,为被动扩散吸收.栀子提取物按组方配比分别与天然冰片(艾片)、人工冰片、人工麝香及合方配伍时栀子苷K值分别为单用栀子提取物组的1.4,1.7,1.1,1.3倍.大鼠鼻腔吸收系数与体外黏膜渗透系数有很好的相关性,KA =0.2206K1+ 0.559(r =0.991 0).结论:醒脑静组方配伍后可显著增加栀子苷的鼻腔吸收,方中冰片发挥了主要的促吸收作用.     

The effects of notoginsenoside R₁ on the intestinal absorption of geniposide by the everted rat gut sac model

Ethnopharmacological relevance

Geniposide is derived from Gardenia jasminoides Ellis (Rubiaceae). Its anti-inflammatory, antithrombotic effects as well as its preventive effect against ischemic stroke have been reported. Radix notoginseng (Chinese name tienchi or sanqi) is the dried root of Panax notoginseng (Burk.) F.H. Chen, an herb noted for its promotion of blood circulation, blood stasis removal and pain alleviation, and has been widely utilized for the prevention and treatment of microcirculatory disturbances in China and other Asian countries for many years. Notoginsenoside R₁ is an effective and structurally representative bioactive constituent of R. notoginseng. In our preliminary study, notoginsenoside R₁ was able significantly to improve the bioavailability of geniposide in beagle dogs, but the underlying mechanisms remain unknown.

Materials and Methods

The present study aimed to investigate the intestinal kinetic absorptive characteristics of geniposide as well as the absorptive behavior influenced by the co-administration of notoginsenoside R₁ using an in vitro everted rat gut sac model.

Results

The results showed good linear correlation between the geniposide absorption in sac contents and the incubation time from 0 to 120 min. The concentration dependence showed a non-linear correlation between the geniposide absorption and the concentrations 0.356–1.424 mg/mL, the absorption was saturated about 1.424 mg/mL. Notoginsenoside R₁ at 0.1 and 0.2 mg/mL concentrations was able significantly to enhance the absorption of geniposide (1.424 mg/mL) by 1.7- and 1.4-fold. Moreover, verapamil, a well-known P-glycoprotein inhibitor, was able significantly to elevate the absorption of geniposide 2.4-fold. Notoginsenoside R₁ influenced geniposide's absorption in a way similar to that of a P-glycoprotein inhibitor.

Conclusions

In conclusion, notoginsenoside R₁ significantly enhances the intestinal absorption of geniposide. As for the mechanism underlying the improvement of geniposide's bioavailability, it is proposed that notoginsenoside R₁ was able to decrease the efflux transport of geniposide by P-glycoproteins.     

Anti-diabetic and anti-cataract effects of Chromolaena odorata Linn., in streptozotocin-induced diabetic rats

Ethnopharmacological relevance

Chromolaena odorata Linn., is used in traditional Indian medicine in the treatment of diabetes and eye problems.

Aim of the study

The present study was designed to investigate the effect of the ethanol extract Chromolaena odorata leaves (ACO) in streptozotocin (STZ; 45 mg/kg, i.v) induced diabetes and cataract in rats.

Materials and methods

Different doses of ACO (200 and 400 mg/kg) was administered once daily for eight weeks to STZ-induced diabetic rats. To know the mechanism of action of title plant, AUC_glucose, AUC_insulin, Homeostatic Model Assessment (HOMA), insulin tolerance test (ITT) and glucose uptake by rat hemi-diaphragms were carried out. Further, cataract score was taken once in a week upto eight weeks and opacity index was measured. HPLC fingerprinting profiling of ACO was also carried out.

Results

Administration of ACO exhibited significant reduction in glucose, HOMA, lipid profiles and significantly improved glucose and insulin tolerance, glycogen content, glucose uptake by skeletal muscle, serum insulin and HDL-c levels. In addition, ACO also decreased oxidative stress by improving endogenous antioxidants. Further, treatment of ACO showed significantly reduced onset and extent of cataract.

Conclusion

The present data suggested that the treatment of ACO reversed the STZ-induced diabetes and cataract in rats. The observed beneficial effects may be mediated by interacting with multiple targets operating in diabetes mellitus and its complication. Taken together, this study provided the scientific evidence for the traditional use of Chromolaena odorata.     

Effect of decursin on the pharmacokinetics of theophylline and its metabolites in rats

Ethnopharmacological relevance

Decursin is used as a traditional Asian medicine to treat various women's diseases.

Aim of the study

Herb–drug interaction has become a serious problem since herbal medicine is extensively used in the modern world. This study investigates effects of decursin, on the pharmacokinetics of theophylline, a typical substrate of cytochrome P450 1A2 enzyme, in rats.

Materials and methods

After decursin pretreatment for 3 days, on the fourth day rats were administered decursin and theophylline concomitantly. The blood theophylline and its major metabolites (1-methylxanthine (1-MX), 3-methylxanthine (3-MX), 1-methyluric acid (1-MU), and 1,3-dimethyluric acid (1,3-DMU)) levels were monitored with LC–MS/MS.

Results

The results indicated that the clearance, elimination rate constant (K_el) of theophylline was significantly decreased and area under concentration–time curve (AUC), C_max, half-life was increased in decursin (25 mg/kg) pretreatment when theophylline (10 mg/kg) was given. In the presence of decursin, the pharmacokinetic parameters of three metabolites (1-MX, 1,3-DMU, and 1-MU) were affected and the differences were statistically significant about AUC_24 h parameter.

Conclusion

Our results suggest that patients who want to use CYP1A2-metabolized drugs such as caffeine and theophylline should be advised of the potential herb–drug interaction, to reduce therapeutic failure or increased toxicity of conventional drug therapy.     

Pharmacokinetic study of salvianolic acid A in beagle dog after oral administration by a liquid chromatography–mass spectrometry method: A study on bioavailability and dose proportionality

Ethnopharmacological relevance

Salvianolic acid A (SAA) is one of the main water-soluble components isolated from Salvia miltiorrhiza Bunge. Pharmacological researches revealed that it had various curative activities after oral and intravenous administration, including beneficial effects on diabetes and its complications, cardioprotective effect, anti-platelet aggregation, and so on. However, there is no report regarding the pharmacokinetics of SAA in beagle dogs after oral administration up to now.

Aim of the study

To study the pharmacokinetics of different doses of SAA in beagle dogs and figure out the absolute bioavailability and dose proportionality of SAA after oral administration.

Materials and methods

Male and female beagle dogs were orally administered SAA 5, 10 and 20 mg/kg randomly. The plasma drug concentration was detected by a rapid, sensitive and reproducible liquid chromatography–mass spectrometry (LC–MS) method. The pharmacokinetic parameters were calculated from plasma concentration–time data using the DAS pharmacokinetic software Data Analysis System Version 3.0 program.

Results

After single-dose oral administration of SAA, the mean peak plasma concentration (C_max) values for groups treated with 5, 10 and 20 mg/kg doses ranged from 14.38 to 38.18 µg/L, and the mean area under the concentration–time curve (AUC_(0–t)) values ranged from 38.77 to 130.33 (µg/L⋅ h). SAA showed lack of dose proportionality over the dose range 5–20 mg/kg, based on the power model. However, the increase in systemic exposure with dose appeared linear. The absolute bioavailability was calculated to range from 1.47% to 1.84%.

Conclusion

The pharmacokinetic properties of SAA in beagle dogs after oral administration were characterized as rapid oral absorption, quick clearance, and poor absolute bioavailability. Systemic exposure exhibited lack of dose proportionality over the dose range 5–20 mg/kg. Furthermore, a readily preparative LC–MS method was demonstrated in this study for the research of traditional Chinese medicine.     

Extract of the Chinese herbal formula Huo Luo Xiao LingDan inhibited adjuvant arthritis in rats

Ethnopharmacological relevance

The herbal formula Huo Luo Xiao Ling Dan (HLXL) and its modifications have been used in traditional Chinese medicine for about one hundred years to alleviate pain and inflammation.

Aim

To investigate the effects of HLXL on complete Freund's adjuvant (CFA)-induced multiple-joint arthritis in rats.

Materials and methods

Male Lewis rats, 190–210 g, were immunized subcutaneously at the base of the tail with 200 μl of heat-killed Mycobacterium tuberculosis in mineral oil (5 mg/ml). HLXL (2.30 and 4.60 g/kg) or vehicle control (n = 8 per group) was administered orally (i.g.) once a day between days 16 and 25 post-CFA injection. The rats were observed for signs of arthritis with arthritic changes (erythema, edema, induration) being scored on a scale of 0–4 of increasing severity using a standard scoring system. The maximum arthritis score per rat was 16. A plethysmometer was used to measure edema volume in each paw. Adverse effects of HLXL were monitored by closely observing the animals for unusual behavioral changes. Levels of tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) in local tissue were measured by enzyme-linked immunosorbent assay on day 25 post-CFA.

Results

HLXL significantly decreased arthritis scores between days 23–25 in the 2.30 g/kg group and 21–25 in the 4.60 g/kg group (p < 0.05). It reduced paw edema on days 22 and 24 in the 2.30 g/kg group and on days 20, 22 and 24 in the 4.60 g/kg group compared to control (p < 0.05). Local tissue TNF-α and IL-1β levels on day 25 post-CFA injection were significantly (p < 0.05) lower in rats treated with HLXL than in control rats. No observable adverse effects were found.

Conclusion

The data suggest that HLXL produces significant anti-arthritic effects that may be mediated by suppressing pro-inflammatory cytokines, and it appears to be safe.