Forced Degradation Studies of Aloe Emodin and Emodin by HPTLC

Anthraquinones are natural phenolic compounds, which are reported to act as anti-aging, anti-inflammatory, antioxidant, anti-cancer, laxative and antitumor agents. They are abudant in plants like candle bush, aloes, cascara bark and rhubarb. The present work was to observe the effect of different forced degradation conditions by high-performance thin layer chromatography on potential markers i.e. aloe emodin and emodin. Both aloe emodin and emodin were subjected to various forced degradation studies such as oxidation, acid and alkaline hydrolysis, photolysis, hydrolytic and thermal degradation. Aloe emodin, was more susceptible to acid hydrolysis and degradation was found to a lesser extent under thermal degradation whereas significant degradation was observed under acid hydrolysis, lesser extent was observed under alkali hydrolysis for emodin. Forced degradation studies on aloe emodin and emodin gives information about its storage and intrinsic stability conditions considering the advanced pharmaceutical aspects of formulation.     

高效液相色谱法测定肤舒宁喷雾剂中大黄素和芦荟苷含量简

目的建立测定肤舒宁喷雾剂中大黄素和芦荟苷含量的高效液相色谱法。方法色谱柱采用C18柱（250mm×4. 6mm,5 μm）。大黄素测定时流动相为甲醇-0. 1%嶙酸溶液（80 ： 20）,流速l.OmL/min,检测波长为254 nm,进样量为20 μL,柱温为30℃。芦荟苷测定时流动相为乙腈-水（25 ： 75,V/V）,流速l.OmL/min,检测波长为355 nm,进样量为20 pL,柱温为301。结果以峰面积（F）对进样质量浓度（;T,（ig/mL）进行线性回归,得大黄素回归方程F = 23 151X-3 768. 2,r = 0. 999 9,线性范围为2.400？48. 00 （ig/mL,平均回收率为101.36% ’ RSD为1. 72% ;芦荟苷回归方程F = 7 220. 4 JT - 2 476, r = 0. 999 9,线性范围为5. 000 - 100. 0 （Ag/mL,平均回收率为101.11%,RSD为1.57%。结论该法操作简单,测定结果准确,重复性好,可用于肤舒宁喷雾剂中大黄素和芦荟苷的含量测定。     

Synthesis and Antitumor Activity of Natural Compound Aloe Emodin Derivatives

In this study, we have synthesized novel water soluble derivatives of natural compound aloe emodin 4(a–j) by coupling with various amino acid esters and substituted aromatic amines, in an attempt to improve the anticancer activity and to explore the structure–activity relationships. The structures of the compounds were determined by ¹H NMR and mass spectroscopy. Cell growth inhibition assays revealed that the aloe emodin derivatives 4d, 4f, and 4i effectively decreased the growth of HepG2 (human liver cancer cells) and NCI‐H460 (human lung cancer cells) and some of the derivatives exhibited comparable antitumor activity against HeLa (Human epithelial carcinoma cells) and PC3 (prostate cancer cells) cell lines compared to that of the parent aloe emodin at low micromolar concentrations.     

Stability-indicating Simultaneous HPTLC Method for Olanzapine and Fluoxetine in Combined Tablet Dosage Form

A rapid, selective and stability-indicating high performance thin layer chromatographic method was developed and validated for the simultaneous estimation of olanzapine and fluoxetine in combined tablet dosage form. Olanzapine and fluoxetine were chromatographed on silica gel 60 F₂₅₄ TLC plate using methanol:toluene (4:2 v/v) as the mobile phase and spectrodensitometric scanning-integration was performed at a wavelength of 233 nm using a Camag TLC Scanner III. This system was found to give compact spots for both olanzapine (R_f value of 0.63±0.01) and fluoxetine (R_f value of 0.31±0.01). The polynomial regression data for the calibration plots showed good linear relationship with r²=0.9995 in the concentration range of 100-800 ng/spot for olanzapine and 1000-8000 ng/spot for fluoxetine with r²=0.9991. The method was validated in terms of linearity, accuracy, precision, recovery and specificity. The limit of detection and the limit of quantification for the olanzapine were found to be 30 and 100 ng/spot, respectively and for fluoxetine 300 and 1000 ng/spot, respectively. Olanzapine and fluoxetine were degraded under acidic, basic and oxidation degradation conditions which showed all the peaks of degraded product were well resolved from the active pharmaceutical ingredient. Both drugs were not further degraded after thermal and photochemical degradation. The method was found to be reproducible and selective for the simultaneous estimation of olanzapine and fluoxetine. As the method could effectively separate the drugs from their degradation products, it can be employed as a stability-indicating method.     

Development and Validation of HPTLC Method for Estimation of Tenoxicam and its Formulations

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the estimation of tenoxicam in the microemulsion gels. Tenoxicam was chromatographed on silica gel 60 F₂₅₄ TLC plate, as a stationary phase. The mobile phase was toluene: ethyl acetate: formic acid (6:4:0.3 v/v/v), which gave a dense and compact spot of tenoxicam with a R_f value of 0.38±0.03. The quantification was carried out at 379 nm. The method was validated in terms of linearity, accuracy, precision and specificity. To justify the suitability, accuracy and precision of the proposed method, recovery studies were performed at three concentration levels. Statistical analysis proved that the proposed method is accurate and reproducible with linearity in the range of 100 to 400 ng. The limit of detection and limit of quantification for tenoxicam were 25 and 50 μg/spot, respectively. The proposed method can be employed for the routine analysis of tenoxicam as well as in pharmaceutical formulations.     

Development and validation of a high-performance thin layer chromatography method for the determination of cholesterol concentration

An accurate, sensitive, precise, reliable, and quick method for the determination of cholesterol content by high-performance thin layer chromatography is developed. In this method, aluminum-backed precoated silica gel 60 F₂₅₄ plates were used as the stationary phase and the samples were sprayed with the help of CAMAG sample applicator Linomat 5. The chromatogram was developed with the mobile phase consisting of chloroform:methanol (9.5:0.5, v/v). The samples were detected using CAMAG Scanner 4 and evaluated using the method developed on winCATS software. Densitometric analysis of cholesterol was performed in absorbance mode at 200 nm. In this solvent system, cholesterol gave a compact spot with an R_f value of 0.63 ± 0.03. The linear regression analysis of data for the calibration curve showed good linearity over a concentration range of 2–7 μg/spot with a regression value of 0.99933 and standard deviation of 1.44%. The limit of detection and limit of quantification were found to be 100 ng/spot and 500 ng/spot, respectively. Using the developed method, the concentration of cholesterol in the saponified and unsaponified egg yolk sample was determined. This method was found to be reproducible and can even be used for samples containing complex matrices.     

芦荟大黄素对人永生化角质形成细胞增殖和凋亡作用研究

目的研究芦荟大黄素（AE）对人永生化角质形成细胞（HaCaT）的生长抑制效应和诱导细胞凋亡能力,探讨其治疗银屑病的可能机制。方法四甲基偶氮唑蓝（MTT）法检测芦荟大黄素对HaCaT细胞增殖的抑制作用,倒置显微镜观察细胞形态学变化,流式细胞术检测细胞周期变化及凋亡。结果芦荟大黄素质量浓度在20～80μg／mL范围内可抑制HaCaT细胞增殖且呈剂量依赖性;镜下观察到细胞稀疏,生长减慢,细胞形态拉长,细胞被阻滞于S期而凋亡。结论芦荟大黄素能抑制HaCaT细胞的增殖、诱导HaCaT细胞的凋亡。可用于治疗银屑病。     

Aloe‐Emodin Quinone Pretreatment Reduces Acute Liver Injury Induced by Carbon Tetrachloride

Aloe contains several active compounds including aloin, a C‐glycoside that can be hydrolyzed in the gut to form aloe‐emodin anthrone which, in turn, is auto‐oxidized to the quinone aloe‐emodin. On the basis of the claimed hepatoprotective activity of some antraquinones, we studied aloe‐emodin in a rat model of carbon tetrachloride (CCl₄) intoxication, since this xenobiotic induces acute liver damage by lipid peroxidation subsequent to free radical production. Twelve rats were treated with CCl₄ (3 mg/kg) intraperitoneally and six were protected with two intraperitoneally injections of aloe‐emodin (50 mg/kg; CCl₄+aloe‐emodin); six other rats were only aloe‐emodin injected (aloe‐emodin) and six were untreated (control). Histological examination of the livers showed less marked lesions in the CCl₄+aloe‐emodin rats than in those treated with CCl₄ alone, and this was confirmed by the serum levels of L‐aspartate‐2‐oxoglutate‐aminotransferase (394±38.6 UI/l in CCl₄, 280±24.47 UI/l in CCl₄+aloe‐emodin rats; P<0.05). We also quantified changes in hepatic albumin and tumour necrosis factor‐α mRNAs. Albumin mRNA expression was significantly lower only in the liver of CCl₄ rats (P<0.05 versus control) and was only slightly reduced in the CCl₄+aloe‐emodin rats. In contrast tumour necrosis factor‐α mRNA was significantly higher (P<0.05) in the CCl₄ than the control rats and almost equal in the CCl₄+aloe‐emodin, aloe‐emodin and control groups. In conclusion, aloe‐emodin appears to have some protective effect not only against hepatocyte death but also on the inflammatory response subsequent to lipid peroxidation.     

HPTLC Method for the Simultaneous Estimation of Valsartan and Hydrochlorothiazide in Tablet Dosage Form

A simple, precise, accurate and rapid high performance thin layer chromatographic method has been developed and validated for the simultaneous estimation of valsartan and hydrochlorothiazide in combined dosage forms. The stationary phase used was precoated silica gel 60F₂₅₄. The mobile phase used was a mixture of chloroform: methanol: toluene: glacial acetic acid (6:2:1:0.1 v/v/v/v). The detection of spots were carried out at 260 nm. The method was validated in terms of linearity, accuracy, precision and specificity. The calibration curve was found to be linear between 300 to 800 ng/spot for valsartan and 100 to 600 ng/spot for hydrochlorothiazide. The limit of detection and the limit of quantification for the valsartan were found to be 100 and 300 ng/spot respectively and for hydrochlorothiazide 30 and 100 ng/spot respectively. The proposed method can be successfully used to determine the drug content of marketed formulation.     

Development and Validation of a HPTLC Method for Simultaneous Estimation of L-Glutamic Acid and γ-Aminobutyric Acid in Mice Brain

A new robust, simple and economic high performance thin layer chromatographic method was developed for simultaneous estimation of L-glutamic acid and γ-amino butyric acid in brain homogenate. The high performance thin layer chromatographic separation of these amino acid was achieved using n-butanol:glacial acetic acid:water (22:3:5 v/v/v) as mobile phase and ninhydrin as a derivatising agent. Quantitation of the method was achieved by densitometric method at 550 nm over the concentration range of 10-100 ng/spot. This method showed good separation of amino acids in the brain homogenate with R_f value of L-glutamic acid and γ-amino butyric acid as 21.67±0.58 and 33.67±0.58, respectively. The limit of detection and limit of quantification for L-glutamic acid was found to be 10 and 20 ng and for γ-amino butyric acid it was 4 and 10 ng, respectively. The method was also validated in terms of accuracy, precision and repeatability. The developed method was found to be precise and accurate with good reproducibility and shows promising applicability for studying pathological status of disease and therapeutic significance of drug treatment.     

Development and Validation of a HPTLC Method for Simultaneous Quantitation of Flunarizine Dihydrochloride and Propranolol Hydrochloride in Capsule Dosage Form

A simple, precise, accurate, and rapid high-performance thin layer chromatographic method has been developed and validated for the simultaneous quantitation of flunarizine dihydrochloride and propranolol hydrochloride in a combined capsule dosage form. The method was carried out on precoated silica gel 60 F₂₅₄ TLC aluminum plate, (20×10 cm²). The solvent system was ethyl acetate:methanol:glacial acetic acid in the proportion of 8:1:1, (v/v/v). R_f value for flunarizine dihydrochloride and propranolol hydrochloride was found to be 0.62±0.02 and 0.18±0.02, respectively. The linearity regression analysis for calibration showed 0.999 and 0.999 for flunarizine dihydrochloride and propranolol hydrochloride with respect to peak area and height in the concentration range of 50-350 ng/spot and 500-3500 ng/spot, respectively. Accuracy of recovery studies was found to be 98-100.28 and 99.11-99.45% for flunarizine dihydrochloride and propranolol hydrochloride, respectively. The amounts of drug in marketed formulation were 100.5 and 101.25% of flunarizine dihydrochloride and propranolol hydrochloride, respectively. The method developed can be used for routine analysis in bulk drug and capsule dosage form.     

Antibacterial Activity of the Iraqi Rheum ribes. Root

Abstract

The antibacterial activity of the ethanol, aqueous, and organic extracts from the root of Rheum ribes. Linn (Polygonaceae) was examined. Four anthraquinone aglycone components, chrysopahnol, physcion, aloe emodin, and emodin, were isolated from the biologically active extract and identified by spectroscopic analysis. Emodin is recorded for the first time in this species. The MIC values of the biologically active extracts, aloe emodin, and emodin, were 500, 125, 250, and 63 µg/mL against Staphylococcus aureus., respectively. The extracts and compounds did not inhibit Pseudomonas aeruginosa. and Escherichia coli. at the highest concentration tested, 4000 and 250 µg/mL, respectively.     

Central composite design expert-supported development and validation of HPTLC method: Relevance in quantitative evaluation of protopine in Fumaria indica

The current study was executed for method development, validation and to estimate the concentration of protopine in methanolic extract of Fumaria indica by high-performance thin-layer chromatography (HPTLC). Isolation of bioactive compounds was carried out using the mobile phase, toluene:ethyl acetate:diethyl amine (8:2.5:0.5 v/v/v), and detected at wavelength 290 nm. This method was validated for precision, specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), etc. The calibration range was found to be 500–5000 ng/spot for the bioactive compound. Protopine was separated with an R_f value of 0.22 ± 0.03. The method was validated for linearity (r2 ≥ 0.996 ± 0.082), accuracy 98.75–102.12%), and RSD of precision (0.49–2.07) with a calibration curve range of 500.00–5000.00 ng/spot. The LOD and LOQ were found to be 83.92 ng/spot and 254.30 ng/spot., respectively. The Central Composite design expert was applied for the validation of robustness. Three independent variables such as the volume of toluene in solvent system, chamber saturation time and wavelength were investigated. The results indicated that a slight change in these variables had no significant effect on the peak response. This developed HPTLC method is simple, precise, robust, specific, rapid, and cost effective. It could be used for quality control study and quantification of protopine in the plant extract and different herbal formulations containing the plant species.     

High-Performance Liquid Chromatographic and High-Performance Thin-Layer Chromatographic Method for the Quantitative Estimation of Dolutegravir Sodium in Bulk Drug and Pharmaceutical Dosage Form

Simple, sensitive, precise, and specific high-performance liquid chromategraphic (HPLC) and high-performance thin-layer chromatographic (HPTLC) methods for the determination of dolutegravir sodium in bulk drug and pharmaceutical dosage form were developed and validated. In the HPLC method, analysis of the drug was carried out on the ODS C₁₈ column (150 × 4.6 mm, 5 μm particle size) using a mixture of acetonitrile: water (pH 7.5) in the ratio of 80:20 v/v as the mobile phase at the flow rate 1 mL/min at 260 nm. This method was found to be linear in the concentration range of 5–35 μg/mL. The peak for dolutegravir sodium was observed at 3.0 ± 0.1 minutes. In the HPTLC method, analysis was performed on aluminum-backed plates pre-coated with silica gel G60 F₂₅₄ using methanol: chloroform: formic acid in the proportion of 8:2:0.5 v/v/v as the mobile phase. This solvent system was found to give compact spots for dolutegravir sodium with the Rf value 0.77 ± 0.01. Densitometric analysis of dolutegravir sodium was carried out in the absorbance mode at 265 nm. Linear regression analysis showed good linearity with respect to peak area in the concentration range of 200–900 ng/spot. The methods were validated for precision, limit of detection (LOD), limit of quantitation (LOQ), accuracy, and specificity. Statistical analysis showed that both of the methods are repeatable and specific for the estimation of the said drug. The methods can be used for routine quality control analysis of dolutegravir sodium.     

Emodin is a novel alkaline nuclease inhibitor that suppresses herpes simplex virus type 1 yields in cell cultures

Background and purpose:Most antiviral therapies directed against herpes simplex virus (HSV) infections are limited to a small group of nucleoside analogues that target the viral polymerase. Extensive clinical use of these drugs has led to the emergence of resistant viral strains, mainly in immunocompromised patients. This highlights the need for the development of new anti-herpesviral drugs with novel targets. Herein the effects of a plant anthraquinone, emodin, on the HSV-1 alkaline nuclease activity and virus yields were investigated.Experimental approach:HSV-1 alkaline nuclease activity was examined by nuclease activity assay. Inhibition of virus yields was measured by plaque reduction assay and immunohistochemical staining. Interaction between emodin and alkaline nuclease was analysed by docking technology.Key results:Emodin specifically inhibited the nuclease activity of HSV-1 UL12 alkaline nuclease in a biochemical assay. Plaque reduction assay revealed that emodin reduced the plaque formation with an EC(50) of 21.5+/-4.4 muM. Immunohistochemical staining using the anti-nucleocapsid protein antibody demonstrated that emodin induced the accumulation of viral nucleocapsids in the nucleus in a dose-dependent manner. Docking analysis further suggested that the inhibitory effect of emodin on the UL12 activity may result from the interaction between emodin and critical catalytic amino acid residues of UL12.Conclusions and implications:Our findings suggest that emodin is a potent anti-HSV agent that inhibits the yields of HSV-1 via the suppression of a novel target, UL12.British Journal of Pharmacology (2008) 155, 227-235; doi:10.1038/bjp.2008.242; published online 16 June 2008.     

高效液相色谱法测定穿虎痛风合剂中大黄素含量

目的 建立测定穿虎痛风合剂中大黄素含量的高效液相色谱法.方法 采用Agilent Zorbax C18柱(250 mm×4.6 mm,5μm),以甲醇-0.1%磷酸溶液(80:20)为流动相,柱温为35℃,流速为1.0 mL/min,检测波长为254 nm.结果 大黄素进样量在5.742～860.13 μg范围内与峰面积呈良好线性关系(r=0.999 9),平均加样回收率为98.95%,RSD=0.99%(n=9).结论 所建立的方法简便可靠、分离度好,可用于穿虎痛风合剂的质量控制.     

Development and Validation of a Reversed-Phase High-performance Liquid Chromatography Method for Determination of Desmopressin in Chitosan Nanoparticles

A simple isocratic reversed-phase high performance liquid chromatographic method was developed for determination of released desmopressin from chitosan nanoparticles in the in vitro media. The chromatographic separation was achieved with acetonitrile/water (25:75, v/v), in which water contained 0.1% v/v trifluoroacetic acid with pH=2.5 as mobile phase, a Chromolith^® Performance RP-18e column (150×4.6 mm; 5 μm) kept at 40° and ultraviolet detection at 220 nm. The compound was eluted isocritically at a constant flow rate of 1.6 ml/min. The method was validated according to the International Conference on Harmonisation guidelines. The validation characteristics included accuracy, precision, linearity rang, selectivity, limit of detection, limit of quantitation and robustness. The calibration curve was linear (r>0.9999) over the concentration rang 0.5-100 μg/ml. The limit of detection and limit of quantitation in the release media were 0.05 and 0.5 μg/ml, respectively. The proposed method had an accuracy of and intra- and inter-day precision <4.2. Furthermore, to evaluate the performance of the proposed method, it was used in the analysis of desmopressin level in real samples containing chitosan nanoparticles in the in vitro media.     

HPLC法测定脑塞安胶囊中大黄素和大黄酚含量

目的用HPLC方法测定脑塞安胶囊中大黄素和大黄酚的总含量。方法采用外标法以甲醇-0．1％磷酸（85：15）为流动相,检测波长为254nm,流速为1．0mL／min。结果大黄素和大黄酚分别在0．2～6．4μg／mL（r=1．0000）和0．8—25．6μg/mL（r=0．9994）范嗣内呈良好的线性,大黄素与大黄酚总平均回收率为96．9％,其RSD值为0．5％（n=9）。结论本法简便、准确、灵敏、重复性良好,适用于脑塞安胶囊的质量控制。     

高效液相色谱法测定肝炎宁胶囊中大黄素的含量

报道了肝炎宁胶囊中大黄素的提取方法，采用高效液相色谱法测定了肝炎宁胶囊中大黄素的含量．为评价含大黄素类药材及其制剂的质量提供了一个准确、灵敏和快速的测定方法．     

不同产地首乌藤的大黄素含量比较

目的建立首乌藤中大黄素含量测定方法，并比较不同产地首乌藤的大黄素含量。方法采用酸水解和氯仿回流提取方法制备供试品溶液，用高效液相色谱（HPLC）法测定首乌藤药材的大黄素含量。流动相为甲醇-0．2mol／L磷酸二氢钠溶液（80：20，用磷酸调pH值至3．0），检测波长为444nm，灵敏度为1．0AUFS。结果大黄素进样量在0．046～0．152μg范围内与峰面积线性关系良好（r=0．9996），加样回收率为98．94％，RSD=0．93％（n=6）。江苏（两批次）、贵州、河南、湖北产首乌藤药材的大黄素含量分别为0．0756％，0．0504％，0．1721％，0．0184％，0．055％。结论不同产地的首乌藤药材的大黄素含量差异显著。