Anti-platelet effect of the constituents isolated from the barks and fruits of<Emphasis Type="Italic">Magnolia obovata</Emphasis>

In the course of our work on anti-platelet constituents from plants, five phenolic compounds, magnolol, honokiol, obovatol, methyl caffeate, and syringin, were isolated from the methanol extracts of the barks and fruits of Magnolia obovata. The compounds were identified based on the spectroscopic data. Methyl caffeate was isolated for the first time from the genus Magnolia and it showed 3 approximately 4-folds higher potency than ASA. The activities of obovatol and honokiol were comparable to ASA. Magnolol and syringin showed only very mild inhibitory effects to all the stimulators.     

高效液相色谱法测定上消合剂中厚朴酚与和厚朴酚的含量研究

目的:运用反相高效液相色谱法测定上消合剂中厚朴酚及和厚朴酚的含量.方法:采用ZorbaxC18柱,甲醇-水(73:27)为流动相,检测波长为294nm.结果:厚朴酚的回收率为94.88%、RSD为0.97%(n=9);和厚朴酚的回收率为94.79%、RSD为1.55%(n=9).结论:简便、快速、重现性好,可作为上消合剂的含量测定方法.     

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.     

气相色谱法测定加味藿香正气丸中百秋李醇、厚朴酚、和厚朴酚含量

目的建立加味藿香正气丸中百秋李醇、厚朴酚、和厚朴酚的GC含量测定方法.方法色谱柱Rtx-5柱(30 m×0.32 mm×0.5 μm);以正十八烷为内标;柱温采用程序升温起始150 ℃,保持23 min,8℃/min升至230℃,保持35 min;进样口温度300℃;检测器(FID)温度300℃;载气为氮气,流速为1.0 ml·min-1;进样量1μl,分流比为201.结果百秋李醇在0.082～0.82 mg·ml-1浓度范围内,与对照品峰面积与内标峰面积之比值呈良好的线性关系(r=0.999 9),平均回收率为99.6%(RSD1.5%,n=6);厚朴酚在0.504～5.04 mg·ml-1浓度范围内,与对照品峰面积与内标峰面积之比值呈良好的线性关系(r=0.999 6),平均回收率为100.2%(RSD=1.4%,n=6);和厚朴酚在0.254～2.54 mg·ml-1浓度范围内,与对照品峰面积与内标峰面积之比值呈良好的线性关系(r=0.999 8),平均回收率为100.4%(RSD=1.4%,n=6)结论该方法简单、准确,可作为加味藿香正气丸的质量控制.     

Construction,characterization, and bioavailability evaluation of honokiol-loaded porous starch by melting method without any solvent

In the present study, the porous starch (PS) was used as an efficient carrier of honokiol (HK), and the HK-loaded PS (HPS) delivery system was prepared by melting method without using organic solvents. Its physical-chemical properties, solubility and oral bioavailability were also investigated. The obtained results proved that the HK in the HPS was mostly amorphous when it was loaded into the PSs with 87.54 ± 1.52% of encapsulation efficiency (EE) and 12.51 ± 0.22% of drug loading (DL) capacity. The water-solubility of the HPS was increased to 115.27 ± 2.92 μg/mL (pH = 1.2, artificial gastric juice (AGJ)), 161.58 ± 3.42 (pH = 6.8, artificial intestinal juice (AIJ)) and 148.5 ± 1.89 μg/mL (pH = 5.5, simulated tumor microenvironment), being 6.07, 4.38 and 4.87-folds higher than free HK. In vitro dissolution tests showed the HK was significantly higher from HPS than from free HK. Furthermore, compared with free HK, the release rate and the bioavailability was also substantially improved for HK from the HPS. Meanwhile, the HPS generated a higher inhibition to HepG2 cells than free HK.     

Honokiol, a natural therapeutic candidate, induces apoptosis and inhibits angiogenesis of ovarian tumor cells

OBJECTIVES: To observe the anti-tumor activities of honokiol on human ovarian tumor in vitro and in vivo. STUDY DESIGN: Cells were treated with honokiol, and the effects on proliferation and apoptosis were examined by MTT, DNA ladder, Hoechst staining, and flow cytometry assays. Expression of Bcl-2 members and caspase-3 were assessed. Measurements of tumor volume and microvessel densities (MVDs) were performed. RESULTS: Honokiol significantly inhibited proliferation and induced apoptosis, with alteration of Bcl-2 members and caspase-3. Administration of honokiol to tumor-bearing animals decreased MVD and resulted in inhibition of tumor growth. CONCLUSIONS: Honokiol could induce apoptosis and inhibit angiogenesis in vitro and in vivo, suggesting a novel and attractive therapeutic candidate for ovarian tumor treatment.     

用高效液相色谱法同时测定藿香正气口服液中厚朴酚和厚朴酚与橙皮苷的含量

目的测定藿香正气口服液中有效成分厚朴酚、和厚朴酚与橙皮苷的含量而用于其质量控制。方法采用高效液相色谱(HPLC)的梯度洗脱法,在ODS柱上以甲醇-水(50∶50￣80∶20)为流动相进行分离,于294nm测定。结果橙皮苷、厚朴酚与和厚朴酚进样量分别在0.4400￣0.7920μg、0.0324￣0.1620μg和0.0392￣0.1960μg范围内与峰面积线性关系良好,相关系数为0.9997、0.9990和0.9991,平均回收率为100.1%、99.1%和101.3%。结论建立的HPLC方法对于所测定的三种有效成分具有良好的色谱分离性。该方法表现出了精密度好、准确度高、简便和稳定等特点,可用于制剂的质量控制。     

厚朴温中丸质量标准的研究

目的:建立和完善厚朴温中丸的质量标准。方法:采用薄层色谱法对方中木香、厚朴、甘草进行定性鉴别;采用HPLC法测定了方中君药厚朴中厚朴酚与和厚朴酚的总含量。结果:鉴别结果理想,阴性对照无干扰;厚朴酚平均加样回收率为99.2%,RSD=1.2%(n=6);和厚朴酚的平均加样回收率为100.0%,RSD=2.5%(n=6)。结论:本方法快速简便,准确,可控制该制剂的质量。     

Honokiol up-regulates prostacyclin synthease protein expression and inhibits endothelial cell apoptosis

Honokiol is a bioactive compound extracted from the Chinese medicinal herb Magnolia officinalis. We recently demonstrated that honokiol inhibited arterial thrombosis through stimulation of prostacyclin (PGI2) generation and endothelial cell protection. The current study is designed to investigate its mechanism of stimulation of PGI2 generation and cell protection. 6-keto-PGF1alpha, the stable metabolite of PGI2, in the media of rat aortic endothelial cells was measured with radioimmunoassay kits. Indomethacin, an inhibitor of cyclooxygenase (COX) and tranylcypromine, a prostacyclin synthease inhibitor were used to ascertain the target enzyme affected by honokiol. Prostacyclin synthease protein levels in endothelial cells were determined by Western blot analysis using an anti-PGI2 synthease rabbit polyclonal antibody. Flow cytometry was used to quantify the apoptotic cells and spectrophotometry was used to test the caspase-3 activity. Honokiol (0.376-37.6 microM) increased the level of 6-keto-PGF1alpha in the media of normal endothelial cells. It counteracted the inhibitory effect of tranylcypromine on the PGI2 generation, but did not influence the effect of indomethacin; evidently, honokiol up-regulated the expression of prostacyclin synthease in the endothelial cells. These effects showed perfect concentration-dependent behavior. In addition, at lower concentration (0.376-3.76 microM), honokiol significantly decreased the percentage of apoptotic endothelial cells induced by oxidized low-density lipoprotein (ox-LDL) and significantly lowered the activity of caspase-3 stimulated by ox-LDL. A high dose of honokiol (37.6 microM), however, failed to influence either of them. In conclusion, honokiol augments PGI2 generation in normal endothelial cells; its effect on PGI2 generation attributes to up-regulation of prostacyclin synthease expression; its cell protection may be correlated with its inhibition on apoptosis of endothelial cells. These findings have partly revealed the molecular mechanism of honokiol on inhibiting arterial thrombosis.     

HPLC法测定暑湿清胶囊中厚朴酚及和厚朴酚的含量

目的:建立HPLC法测定暑湿清胶囊中厚朴酚与和厚朴酚含量的方法。方法:采用高效液相色谱法,色谱柱:Waters C18柱(250mm×4·6mm,5μm),流动相:甲醇-水(78:22),检测波长:294nm,流速:1·0mL·min-1。结果:厚朴酚的线性范围为0·08～4·06μg,平均加样回收率为98·23%(RSD=1·28%,n=6);和厚朴酚的线性范围为0·32～16·04μg,平均加样回收率为98·10%(RSD=0·54%,n=6)。结论:本方法简便、准确、可靠,灵敏度高,重现性好,可用于暑湿清胶囊的质量控制。