Combinative method using HPLC quantitative and qualitative analyses for quality consistency assessment of a herbal medicinal preparation

A selective and efficient quality consistency assessment system was developed for monitoring the manufacturing processes of a Chinese herbal preparation, qingfu guanjieshu (QFGJS) capsule, and for assessing its stability over time. This system is based on quantitative determination of four marker compounds, i.e., sinomenine, paeoniflorin, paeonol, and curcumin, and on qualitative fingerprinting analysis of QFGJS using high-performance liquid chromatography-photodiode array detection (HPLC-DAD) method. The separation was performed on a Phenomenex ODS column by gradient elution with acetonitrile and aqueous phase (containing 0.1% phosphoric acid, adjusted with triethylamine to pH 3.5+/-0.2) at a flow-rate of 1.0 ml/min. In fingerprinting analysis, the chemical characteristics of four herbs present in QFGJS (excluding radix Aconiti Lateralis Preparata) were present in the HPLC chromatographic file. In addition, quantitative determination of hypaconitine was carried out with our published HPLC method as a supplement for quality control of the radix Aconiti Lateralis Preparata in QFGJS. The results showed that the contents of these five marker compounds and HPLC fingerprint profiles of three batches of QFGJS products collected at 3 months after production in the stability testing were relatively consistent. This well-developed method could be used for quality assessment of the complex preparations of herbal medicine.     

Influence of co-administered danshensu on pharmacokinetic fate and tissue distribution of paeonol in rats

Cortex Moutan (root bark of Paeonia suffruticosa Andrew) and Radix Salviae miltiorrhizae (root and rhizome of Salvia miltiorrhiza Bunge) are two herbs widely used in traditional Chinese medicine (TCM) to treat cerebrovascular and cardiovascular diseases. In clinical practice, these two herbs are prescribed together. Studies on the pharmacokinetic interaction between the active constituents of these two herbs (paeonol and danshensu, respectively) can provide substantial foundation for understanding its mechanism and empirical evidence to support the clinical practice. A simple and sensitive high-performance liquid chromatographic (HPLC) method coupled with ultraviolet detector was developed for determination of paeonol in plasma and different tissues (heart, liver, spleen, lung, kidney, and brain) of male Sprague-Dawley rats. When co-administering danshensu, the peak plasma concentration of paeonol was decreased (p?相似文献   

HPLC法测人血浆中丹皮酚浓度及其药代动力学研究

目的：建立HPLC丹皮酚胶囊血浓度测定方法，评价丹皮酚胶囊的药代动力学特点。方法：24名健康志愿者单剂量口服160mg丹皮酚胶囊，按设定时间采集肘静脉血经乙睛萃取处理，以XB—C18（250mm×4．6mm，5μm）色谱柱为固定相，四氢呋喃-甲醇-水-磷酸（6：60：34：0．1）为流动相测定丹皮酚血浆浓度。采用DAS2．0计算丹皮酚主要药动学参数。结果：丹皮酚线性范围10—500mg／mL，最低检出浓度为10ng／mL。主要药代动力学参数：Cmax为（116±46）ng／mL，tmax为（1．02±0．13）h，t1/2为1．03h。结论：建立的HPLC方法特异性强、灵敏度高，可用于丹皮酚血药浓度测定和人体药动学研究。     

Glucuronidation is the dominating in-vivo metabolism pathway of herbacetin:elucidation of herbacetin pharmacokinetics after intravenous and oral administration in rats

OBJECTIVE To map a comprehensive metabolic pathway of herbacetin in rats,specifically,to elucidate the biotransformation of herbacetin in vivo and to simultaneously monitor the pharmacokinetic process of both parent drug and its major metabolites.METHODS liquid chromatography/ion trap mass spectrometry(LC/MS n) and ultra-liquid chromatography coupled with mass spectrometry(UPLC/MS) were combined in the current study for qualitative and quantitative determinations of herbacetin and its metabolites in bile,urine and feces after both oral and intravenous administration of herbacetin to rats.Enzyme kinetic studies on the intestinal and hepatic metabolism of herbacetin were further conducted to elucidate metabolic profiles of herbacetin in rat tissues and organs.Additionally,plasma concentration profiles of herbacetin and its metabolites in rats were obtained to characterize the overall pharmacokinetic behavior of herbacetin.RESULTS It was found that herbacetin was excreted primarily from rat urine in the form of glucuronide-conjugations.Subsequent in vitro enzyme kinetic studies and in vivo pharmacokinetic investigations suggested an extensive hepatic metabolism of herbacetin and the high exposure of herbacetin-glucuronides in systemic circulation.The clearance,half-life and bioavailability of herbacetin in rats were determined as(16.4±1.92)mL·kg~(-1)·min~(-1),(11.9±2.7)min,and 1.32%,respectively.On basis of these findings,a comprehensive metabolic pathway of herbacetin in rats was composed.In addition,a physiology based pharmacokinetic(PBPK) model was successfully developed with the aid of the Gastro Plus to simulate the pharmacokinetic process of herbacetin in rats.Application of the PBPK modeling can provide a useful starting point to understand and extrapolate pharmacokinetic parameters among different species,populations,and disease states.CONCLUSION After oral administration,herbacetin was subjected to colonic degradation and extensive first pass metabolism,with glucuronidation as its dominating in vivo metabolic pathway.     

Metabolism of aromatic plant ketones in rats: acetovanillone and paeonol

1. The metabolism of the plant ketones acetovanillone (4-hydroxy-3-methoxyacetophenone) and paeonol (2-hydroxy-4-methoxyacetophenone), was studied in rats. Identification and quantification of metabolites was carried out by g.l.c.-mass spectometry and g.l.c., respectively, following intragastric doses of 1 mmol/kg. 2. Acetovanillone was rapidly excreted in the urine, mainly unchanged but also as the demethylated compound and three ring-hydroxylated metabolites. Minor additional metabolic pathways produced the para-methoxy derivative, acetoisovanillone, a dimethoxy-hydroxy derivative and two 1-phenylethanol derivatives formed by ketone reduction of acetovanillone and 3,4-dihydroxyacetophenone. 3. Paeonol was metabolized more extensively and larger amounts of the demethylated (resacetophenone) and hydroxylated (mainly 2,5-dihydroxy-4-methoxyacetophenone and a trihydroxyacetophenone) metabolites were excreted. Paeonol was not found to undergo ketone reduction, however, small amounts of the hydroxymethyl derivative formed by omega-oxidation were detected. 4. The metabolites were excreted mainly as glucuronide and/or sulphate conjugates. Faecal recoveries of metabolites were very small and the urinary excretion (48 h) was 97% (acetovanillone) and 61% (paeonol).     

Metabolism of aromatic plant ketones in rats: Acetovanillone and paeonol

1. The metabolism of the plant ketones acetovanillone (4-hydroxy-3-methoxyacetophenone) and paeonol (2-hydroxy-4-methoxyacetophenone), was studied in rats. Identification and quantification of metabolites was carried out by g.l.c.-mass spectometry and g.l.c., respectively, following intragastric doses of 1 mmol/kg.

2. Acetovanillone was rapidly excreted in the urine, mainly unchanged but also as the demethylated compound and three ring-hydroxylated metabolites. Minor additional metabolic pathways produced the para-methoxy derivative, acetoisovanillone, a dimethoxy-hydroxy derivative and two 1-phenylethanol derivatives formed by ketone reduction of acetovanillone and 3,4-dihydroxyacetophenone.

3. Paeonol was metabolized more extensively and larger amounts of the demethylated (resacetophenone) and hydroxylated (mainly 2,5-dihydroxy-4-methoxyacetophenone and a trihydroxyacetophenone) metabolites were excreted. Paeonol was not found to undergo ketone reduction, however, small amounts of the hydroxymethyl derivative formed by ?M-oxidation were detected.

4. The metabolites were excreted mainly as glucuronide and/or sulphate conjugates. Faecal recoveries of metabolites were very small and the urinary excretion (48 h) was 97% (acetovanillone) and 61% (paeonol).     

Diuretic action of paeonol.

Effects of paeonol, a major component of the root bark of PAEONIA SUFFRUTICOSA, on urinary excretion of water (UV), sodium (U (Na)V), potassium (U (K)V), chloride (U (cl)V) and osmolality (U (osm)V) were investigated in bicarbonate saline loaded rats. Paeonol at the doses of 62.5 to 250 mg/kg p.o. produced dose-dependent increases in UV, U (Na)V and U (Cl)V (P < 0.05 or 0.01 vs. control). U (K)V was unchanged at the lower doses and decreased at the highest dose. U (osm)V was also increased by paeonol (P < 0.05 or 0.01). The lowest effective dose of paeonol in diuretic action was 62.5 mg/kg which is somewhat lower than those reported to produce an antiinflammatory action or a reduction of gastric secretion (125 to 500 mg/kg). The highest dose of paeonol produced the same degree of increase in UV as hydrochlorothiazide (HTZ) (10 mg/kg), while the increases in electrolytes excretion by HTZ were significantly greater than by paeonol. These data demonstrate that paeonol has a diuretic action, and suggest that its sites of action in the kidney are different from those of HTZ.     

灯盏花素在正常和模型大鼠中的药代动力学及代谢物研究

目的研究灯盏花素在正常和角叉菜胶致血栓形成大鼠中的药代动力学，并对其血浆样品中主要代谢物进行初步鉴定。方法RP-HPLC法测定静注36 mg·kg^-1灯盏花素后正常和模型大鼠不同时间血浆样品中灯盏乙素浓度，3P97软件拟合房室模型，计算药动学参数；HPLC-PDA(光电二极管阵列)、LC-MS/MS技术分析鉴定血浆样品中的主要色谱峰。结果血浆中灯盏乙素在0.625～80.0 μg·mL^-1(r=0.999 5)线性关系良好，最低定量浓度：0.312 μg·mL^-1；正常和角叉菜胶致血栓形成状态下，灯盏乙素药时曲线均呈现二室开放模型。血浆样品中4个主要色谱峰的可能结构分别为4′，5-二羟基黄酮-7-氧-β-D-葡糖醛酸甲酯苷(M1)、灯盏乙素(M2)、7-甲氧基-4′，5-二羟基-黄酮(M3)和7-甲氧基-4′,5,6-三羟基-黄酮(M4)。结论正常和模型大鼠体内灯盏乙素的药动学参数有显著性差异；灯盏乙素在大鼠血浆样品中的代谢主要是脱羟基和甲基化途径。     

中药水煎剂和免煎颗粒剂牡丹皮中丹皮酚的含量与有效性的比较

目的 比较中药水煎剂与免煎颗粒剂牡丹皮中丹皮酚的含量和有效性并为临床用药提供参考.方法 采用高效液相色谱法测定牡丹皮中丹皮酚的含量,以十八烷基硅烷键合硅胶为填充剂,甲醇-水(45:55)为流动相,检测波长为274nm.结果 免煎颗粒剂牡丹皮中丹皮酚的含量为2.35%,中药饮片的水煎剂中丹皮酚的含量为0.99%.结论 中药水煎剂和免煎颗粒剂牡丹皮中丹皮酚的含量存在差异,但中药水煎剂比免煎颗粒剂的临床疗效更佳.     

Anti-inflammatory and analgesic effects of paeonol in carrageenan-evoked thermal hyperalgesia

1. Paeonol was tested for its anti-inflammatory and analgesic effects in a rat model of carrageenan-evoked thermal hyperalgesia. The possible mechanisms involved in these effects were also investigated. 2. Pre- and post-treatment with paeonol (30, 50 or 100 mg kg(-1), i.p.) dose-dependently inhibited the carrageenan-evoked thermal hyperalgesia. 3. Treatment with paeonol dose-dependently inhibited tumour necrosis factor-alpha (TNF-alpha) and interleukin-lbeta (IL-1beta) formation, but enhanced IL-10 production in the rat paw exudates both at the early (1.5 h) and late phase (4 h) after carrageenan injection. However, inhibition of IL-6 formation by paeonol was only observed at the late phase. 4. Paeonol dose-dependently decreased the formation of prostaglandin E(2) (PGE(2)) in rat paw exudates with a greater inhibition at the late phase. However, inhibition of nitrate generation was observed only during the late phase (at 4 h after carrageenan injection), accompanied by an attenuation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression in paw tissue. 5. Elevated myeloperoxidase activity, an indicator of neutrophil infiltration, in carrageenan-injected paws was also dose-dependently reduced in paeonol-treated rats. 6. Our results suggest that the mechanisms by which paeonol exerts its anti-inflammatory and analgesic effects in this inflammatory model may be associated with decreased production of proinflammatory cytokines, NO and PGE(2) and increased production of IL-10, an anti-inflammatory cytokine, in carrageenan-injected rat paws. In addition, attenuation of the elevated iNOS and COX-2 protein expression as well as neutrophil infiltration in carrageenan-injected paws may also be involved in the beneficial effects of paeonol.     

LC-MS/MS法测定大鼠血浆中吴茱萸碱的浓度及其药代动力学研究

目的：建立用于测定吴茱萸碱血药浓度的液相色谱-串联质谱联用分析方法,并研究吴茱萸碱在大鼠体内的药代动力学。方法：6只大鼠灌胃给药吴茱萸碱100mg/kg,眼底取血,LC-MS/MS法测定血药浓度,并用DAS药代动力学程序拟合计算药代动力学参数。结果：吴茱萸碱浓度在0.2～50ng/mL内,线性关系良好（r^2=0.9997）。提取回收率96.12%～99.46%,日内、日间RSD分别为4.61%～13.51%和5.65%～11.49%。主要药代动力学参数为：Cmax=（5.3±1.5）ng/mL;tmax=（22±8）min;t1/2=（451±176）min。结论：建立的LC-MS/MS方法专属性强,灵敏度高,可用于吴茱萸碱的体内定量分析。     

基于微乳凝胶新载体的丹皮酚经皮给药系统的构建及药代动力学研究

为构建基于微乳凝胶 (microemulsion-based gels, MBGs) 新载体的丹皮酚经皮给药系统, 采用皮肤、血液双位点同步微透析结合LC/MS联用技术测定丹皮酚微乳、微乳凝胶及市售丹皮酚软膏在大鼠皮肤、血液中的药物浓度随时间的变化过程, 并对其药代动力学参数进行比较分析。方法学研究表明, 丹皮酚线性探针体内回收率 (R_{in vivo}) 为 (69.7 ± 4.8) %, 同心圆探针体内回收率为 (51.6 ± 7.2) %。大鼠腹部脱毛, 分别给予丹皮酚微乳 (1% 丹皮酚)、微乳凝胶和市售丹皮酚软膏, 以PBS (pH 7.4) 溶液作为灌流液, 灌流速度为5 μL·mL⁻¹, 每隔20 min收集1次微透析样品, 共收集12 h, 透析液采用LC/MS进行测定。皮肤药动学结果表明丹皮酚微乳、微乳凝胶与市售软膏相比, 显著提高了药物在皮肤组织中的浓度; 血液药动学结果表明微乳凝胶与市售软膏具有相近的生物利用度, 但前者的血药浓度更平稳。本研究所构建的丹皮酚微乳凝胶有望为皮肤湿疹的治疗提供一种新的制剂; 所建立的微透析/LC-MS联用技术能够在体、同步、实时监测大鼠皮肤、血液中的药物浓度, 为经皮给药药代动力学研究提供了新的方法。     

The effects of paeonol on the electrophysiological properties of cardiac ventricular myocytes

Previous studies have shown that "Mudanpi", a Chinese herbal medicine, has a significant cardioprotective effect against myocardial ischaemia. Based on these findings we hypothesised that paeonol, the main component of Mudanpi, might have an effect on the cellular electrophysiology of cardiac ventricular myocytes. The effects of paeonol on the action potential and ion channels of cardiac ventricular myocytes were studied using the standard whole-cell configuration of the patch-clamp technique. Ventricular myocytes were isolated from the hearts of adult guinea-pig by enzymic dispersion. The myocytes were continuously perfused with various experimental solutions at room temperature and paeonol applied in the perfusate. Action potentials and membrane currents were recorded using both current and voltage clamp modes of the patch-clamp technique. Paeonol, at concentrations 160 microM and 640 microM, decreased the action potential upstroke phase, an action associated with the blockade of the voltage-gated, fast sodium channel. The effects of paeonol on both action potential and Na(+) current were concentration dependent. Paeonol had a high affinity for inactivated sodium channels. Paeonol also shortened the action potential duration, in a manner not associated with the blockade of the calcium current, or the enhancement of potassium currents. These findings suggest that paeonol, and therefore Mudanpi, may possess antiarrhythmic activity, which may confer its cardioprotective effects.     

Effects of gut microflora on pharmacokinetics of hesperidin: a study on non-antibiotic and pseudo-germ-free rats

Hesperidin is a biologically active flavanone glycoside occurring abundantly in citrus fruits. In the present study, effects of intestinal microflora on pharmacokinetics of hesperidin were investigated using a pseudo-germ-free rat model treated with antibiotics. After administration of hesperidin to rats, hesperetin, hesperetin glucuronides, and metabolites postulated to be eriodictyol, hemoeriodictyol, and their glucuronides were detected in urine while hesperetin glucuronide was predominantly found in plasma. The plasma concentration-time profile of hesperetin was compared between non-antibiotic-exposed and pseudo-germ-free rats administered this compound. The maximal concentration (C(max)) values of hesperetin in non-antibiotic-exposed and pseudo-germ-free rats were 0.58 and 0.20 μg/ml, respectively, and area under the curve (AUC) values were 6.3 and 2.8 μg-h/ml, respectively. Thus, systemic exposure as evidenced by AUC and C(max) was significantly higher in normal compared to pseudo-germ-free rats. Fecal β-glucosidase activities of non-antibiotic-exposed and pseudo-germ-free rats were 0.21 and 0.11 nmol/min/mg, while fecal α-rhamnosidase activities were 0.37 and 0.12 nmol/min/mg, respectively. The rate of hesperidin transformation to hesperetin was 6.9 and 2.9 nmol/min/g in fecal samples in non-antibiotic-exposed and pseudo-germ-free rats, respectively. Taken together, these results showed that pharmacokinetic differences between non-antibiotic-exposed and pseudo-germ-free rats may be attributed to differing hesperidin uptake, as well as alterations in metabolic activities of intestinal flora.     

Pharmacokinetics of gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, in rat and dog

The pharmacokinetics of gefitinib and its metabolites in rat and dog were investigated in preclinical studies conducted to support the safety evaluation and clinical development of gefitinib, the first EGFR tyrosine kinase inhibitor approved for the treatment of non-small-cell lung cancer. Following intravenous dosing (5 mg kg(-1), gefitinib plasma half-life was 3-6h in rats and dogs, although studies using a more sensitive HPLC-MS assay produced longer estimates of half-life (7-14h). In these studies, plasma clearance was high (male rat: 25 ml min(-1) kg(-1); female rat: 16 ml min(-1) kg(-1); male dog: 16 ml min(-1) kg(-1)), as was the volume of distribution (8.0-10.41 kg(-1) in rat; 6.31 kg(-1) in dog), and exposure in female rats was double that in males. Following administration of [14C]-gefitinib, concentrations of radioactivity in plasma exceeded gefitinib throughout the profile, indicating the presence of circulating metabolites in both rat and dog. An HPLC-MS assay was developed to measure concentrations of gefitinib and five potential metabolites in plasma. All five metabolites were detected in the rat, but at levels much lower than gefitinib. In the dog, exposure to gefitinib and M523595 was similar, with much lower concentrations of M537194 and only trace levels of the other metabolites. This profile of metabolites is similar to that observed in man.     

丹皮酚对体外培养乳鼠心肌细胞~(45)Ca摄取的影响

通过测定体外培养乳鼠心肌细胞~(45)Ca摄取及其搏动频率的变化,观察丹皮酚对心肌细胞Ca~(2+)内流的影响。结果50～400μg/ml的丹皮酚,能显著降低心肌细胞搏动频率,对心肌细胞快相(5min)和慢相(120min)~(45)Ca摄取均有显著抑制作用,且400μg/ml丹皮酚与10μmol/L的维拉帕米的作用相似。提示丹皮酚能抑制心肌细胞的Ca~(2+)内流,可能与阻滞慢钙通道有关。     

Sex difference in the oxidative metabolism of delta 9-tetrahydrocannabinol in the rat.

Oxidative metabolism of delta 9-tetrahydrocannabinol (THC), one of the major components of marihuana, was studied using liver microsomes of adult male and female rats. There was no significant difference in the rates of the cannabinoid oxidation in terms of nmol per min per nmol of liver microsomal cytochrome P450 or of nmol per min per mg of microsomal protein between male and female rats. delta 9-THC was biotransformed to various metabolites including 11-hydroxy-delta 9-THC (11-OH-delta 9-THC), 8 alpha-OH-delta 9-THC, 8 alpha,11-diOH-delta 9-THC, 3'-OH-delta 9-THC by liver microsomes of male rats, while it was oxidized selectively to 11-OH-delta 9-THC by liver microsomes of female rats. After intraperitoneal administration of delta 9-THC, various metabolites were again found in the liver of the male rat, while in the female rat oxidation of the methyl group at the 9-position was a major metabolic pathway. These results demonstrate that an apparent sex-related difference exists in the oxidative metabolism of delta 9-THC in the rat.     

Metabolic profile of Fructus Gardeniae in human plasma and urine using ultra high-performance liquid chromatography coupled with high-resolution LTQ-orbitrap mass spectrometry

1. In China, Fructus Gardeniae was used as a traditional Chinese medicine (TCM) with a wide array of biological activities. The bioactive components identified in Fructus Gardeniae mainly included iridoids, flavonids, pigments, and so on. Among them, iridoids were regarded as important compounds in Fructus Gardeniae. Though analyses of the constituents in biological samples after oral administration of Fructus Gardeniae effective fraction or its active compounds have been reported, few efforts have been made to investigate the metabolic profile of Fructus Gardeniae in humans. In this study, the constituents and metabolites of Fructus Gardeniae in human blood and urine after oral administration of Fructus Gardeniae were investigated using ultra high-performance liquid chromatography (UHPLC) coupled with high-resolution LTQ-Orbitrap mass spectrometery.

2. Totally, 14 constituents (two parent compounds and 12 metabolites) of Fructus Gardeniae were identified in human plasma and urine either by comparing the retention time and mass spectrometry data with that of reference compounds or by the accurate high-resolution MS/MS data of the chemicals. The compounds identified were mainly iridoid glycosides such as geniposide and the derivatives of genipin-O-glucuronide. Among them, 11 metabolites were detected in human plasma and urine while the other three metabolites including geniposidic acid (M1), demethylation derivative of genipin-O-glucuronide (M2), and dehydration product of mono-hydroxylated genipin-O-glucuronide (M9) were only discovered in human urine. Further, the possible metabolic pathways of Fructus Gardeniae in vivo were proposed and the peak area–time curve of the most abundant metabolite genipin-O-glucuronide (M13) in human plasma after oral administration of Fructus Gardeniae was depicted. The results suggested that a metabolic difference existed between rats and humans.

3. The results obtained in the present research would provide basic information to understand the metabolic profile of Fructus Gardeniae in humans and explore the chemicals responsible for the hepatotoxicity of Fructus Gardeniae in vivo. Moreover, it would be beneficial for us to further study the pharmacokinetic behavior of Fructus Gardeniae in humans systematically.     

采用UFLC-IT-TOF/MS鉴定大鼠口服黄芩提取物后胆汁、血浆和尿液中的主要成分(英文)

黄酮类化合物是中国传统中药黄芩的主要活性成分。大鼠口服黄芩提取物后, 采用超快速液相色谱-离子阱飞行时间质谱(UFLC-IT-TOF/MS)对胆汁、血浆和尿液进行分析, 鉴定入血成分和代谢产物。根据对这些成分质谱裂解规律的分析, 共鉴定了36种不同的黄酮类化合物, 其中包括13个新的代谢产物。本实验在体外对黄芩提取物进行分析,鉴定了其中16个黄酮类成分, 大鼠胆汁中鉴定了25个黄酮类化合物, 血浆中15个黄酮类化合物, 尿液中14个黄酮类化合物。结果表明, 黄芩提取物中的黄酮类化合物以葡萄糖醛酸化、硫酸化和甲基化的为主要代谢途径。本实验首次对黄芩提取物的代谢产物进行综合分析。     

Anxiolytic-like effect of paeonol in mice

The present study in mice compared the putative anxiolytic-like effect of paeonol, a phenolic component from the root bark of Paeonia moutan, with the benzodiazepine diazepam in the elevated plus maze and the light/dark box-test. The comparison was also with regard to locomotor activity (open-field test) and myorelaxant potential (inclined plane test). As with 2 mg/kg diazepam, paeonol (at 17.5 mg/kg) increased the percentage of time spent on open arms in the elevated plus maze and increased the time spent in the light area of the light/dark box (at 8.75 and 17.5 mg/kg). Since paeonol, in contrast to diazepam, had no effect on either the number of squares entered in the open-field test or in the inclined plane test, its side-effect profile is considered as superior to the benzodiazepine.