Influence of puerarin,paeoniflorin,and menthol on structure and barrier function of tight junctions in MDCK and MDCK-MDR1 Cells

Objective:In this study,the influence of puerarin,paeoniflorin,and menthol on the structure and barrier function of tight junctions(TJs)in MadineDarby canine kidney epithelial(MDCK)and MDCK-multi-drug resistance 1(MDR1)cells was evaluated to determine the mechanisms by which the drugs cross the bloodebrain barrier(BBB).Method:Cells were treated with puerarin,paeoniflorin,and menthol followed by immunohistochemical staining with occludin,claudin-1,and F-actin.The cells were then observed using laser-scanning confocal microscopy.Average optical density(AOD)of the immunofluorescence images of the proteins were analyzed using ImageJ software while Transepithelial electrical resistance(TEER)was measured using an epithelial voltohmmeter.Results:Confocal microscopy revealed that puerarin-and paeoniflorin-treated tight junction proteins were conspicuous while menthol suppressed their expression.Correspondingly,AOD values of cells treated with puerarin or paeoniflorin,or both showed no difference compared to the control group(P>.05)while the menthol group value was downregulated.In 3 h,TEER of cells not treated with menthol were similar to the control group,while treatment with menthol significantly decreased TEER value(P<.05).In addition,application of menthol decreased TEER in MDCK cells earlier than in MDCK-MDR1 cells.Conclusion:Menthol but not puerarin and paeoniflorin may enhance paracellular transport and improve drug penetration of the BBB by disrupting the structure and,thereby,weakening the barrier function of TJs.

A multiscale study of the penetrationenhancing mechanism of menthol

Objective:Transdermal drug delivery systems represent a critical focus in the pharmaceutics field;however,their use is limited by the fact that many drugs usually pass through the skin with low permeability.Menthol is a common penetration enhancer because of its high penetration-enhancing efficiency and safety.Our research aimed to reveal the penetrationenhancing mechanisms of menthol via a multiscale study.Methods:First,the interaction of menthol with the stratum corneum was studied using vertical Franz diffusion cells obtained from the abdominal skin of rats as a model.Then,the skin samples were observed via transmission electron microscopy.Finally,the interaction of different concentrations of menthol with a mixed lipid model of the stratum corneum was investigated via molecular dynamics simulation using the GROMOS 54A7 force field on a microcosmic level.Results:At concentrations of 3.5%or lower,menthol changed the original structure of the stratum corneum to varying degrees,which increased its fluidity and facilitated the permeation and storage of menthol.Menthol increased the fluidity of the stratum corneum mainly via two mechanisms.First,menthol had strong hydrogen-bonding capability,and it could compete for the lipidelipid hydrogen bonding sites,thereby weakening the stability of the hydrogenbonding network connecting the skin lipids.In addition,menthol had strong affinity for cholesterol,probably due to their similar molecular structures,suggesting that the incorporation of menthol would increase the fluidity of the lipid membrane similarly to cholesterol.Conclusion:The penetration-enhancing mechanism of menthol was explained using in vitro and molecular dynamics simulation methods.These findings may advance the basic research of transdermal drug delivery systems and facilitate the discoveries of novel penetration enhancers.

Chemical Composition of the Essential Oil and Nitrogen Metabolism of Menthol Mint under Different Phosphorus Levels

The purpose of this work was to evaluate the effects of different phosphorus levels (0.05, 0.5, 1 and 2 mM) under nitrogen metabolism and the essential oil profile of menthol mint (Mentha arvensis L.). The relationship between the leaf maturity and the essential oil profile was also explored. The experiment was conducted in a hydroponic system located in a grow chamber during 41 days and after the harvest, nitrate reductase activity, and the -N, amino-N, and soluble sugars levels of each plant part were evaluated. Also the essential oil from young leaves (6th to 8th node) and adult leaves (3rd to the 5th node) was analyzed. An uptake mechanism related to the increase in fresh weight of the roots was promoted with the use of low P levels (0.05 and 0.50 mmol&middotL-1). With 1 mmol&middotL-1 P plants showed in all parts an increased nitrate reductase activity and high levels of nitrate and amino-N in leaves. Plants submitted to the lowest P level (0.05 mmol&middotL-1) presented high levels of menthol. In leaves from 6th to 8th node (mature leaves) menthol level was approximately 87% of the essential oil however leaves from the 3rd to the 5th node (young leaves) showed high levels of pulegone, that can be toxic for humans. The results indicate that the essential oil quality in menthol mint is influenced by the leaf maturity and the P levels. Also it was showed that the oil extracted from mature leaves of plants under low P levels has the best commercial profile.

Nicotine and menthol independently exert neuroprotective effects against cisplatin-or amyloid-toxicity by upregulating Bcl-xl via JNK activation in SH-SY5Y cells

Nicotine and menthol,agonists of nicotinic acetylcholine receptor(nAChR)and transient receptor potential melastatin type 8(TRPM8),serve important roles in the prevention of cell death-involved neurodegenerative diseases.However,the potential synergistic effects of nicotine and menthol on anti-apoptotic ability are still uncertain.In the present study,the potential synergistic effects of nicotine and menthol on cisplatin or amyloidβ1-42 induced cell model of the neurodegenerative diseases were explored by assessing cell viability,TNF-αexpression,caspase-3 activation,and the collapse of mitochondrial membrane potential in human SH-SY5Y neuroblastoma cells.Statistical significance was tested using Student’s t-test or one-way ANOVA with post hoc Newman-Keuls test.The results showed that:Firstly,SH-SY5Y cell viability was obviously increased by the treatments with nicotine and menthol.Secondly,nicotine and menthol independently alleviated cisplatin or amyloidβ1-42 induced TNF-αup-regulation.Thirdly,nicotine and menthol abrogated the effect of cisplatin and amyloidβ25-35 on caspase-3 activation.Interestingly,the effect of cisplatin and amyloidβ1-42 on the collapse of mitochondrial membrane potential was efficiently attenuated by nicotine and menthol treatments.Most importantly,the inhibition of c-jun kinase(JNK)activation abolished the effect of cisplatin,and amyloidβ1-42 stimulated Bcl-xl expression.All these findings indicate that nicotine and menthol independently exert neuroprotective effects by upregulating Bcl-xl via JNK activation.Nicotine and menthol augmented Bcl-xl expression and JNK phosphorylation,and thus they are potential therapeutic targets for altering the progress of neurodegenerative diseases.

Analysis of pathomechanisms involved in side effects of menthol treatment in respiratory diseases

Menthol is frequently used in over the counter medications for common colds and coughs. It was formerly considered to be under the class of herbal medicine, but identification of menthol receptor (TRPM8) moved it from the class of herbal medicine to the molecular pharmacology. It has been documented that menthol reduces dyspnoea and nasal obstruction via stimulation of nasal cold or flow receptors. It has also antitussive and antiirritative effect. Menthol can also induce adverse reactions such as airway irritation, dyspnoea, chest tightness and potentially respiratory failure, mainly in children. The mechanisms responsible for adverse reactions of menthol are not known completely. The adverse reactions of menthol could be due to its effects on TRPA1 channel, relevant to airway irritation. Higher concentrations of menthol stimulate TRPA1 channel causing airway irritation. It also increases mucus production and at the same time reduces cilliary activity leading to mucus stagnation. As the adverse effects were reported mainly at the night it is supposed that suppressed cough reflex during sleep potentiated by menthol induced cough suppression might be responsible for lack of airway mucus clearing and obliteration of small airways. Adverse effects could also be due to consequences of reflexes induced by the menthol action on trigeminal afferents, like apnoea or bronchoconstriction. Menthol is effective in relieving respiratory symptoms, but cough and cold medications should be used with caution. Recommendations are low concentrations of menthol used locally (intranasal) and not combined with camphor or cineole, as they may have additive effects and should be avoided in children under 2 years. Further data are necessary to completely elucidate potential risks of over the counter menthol medication in children but based on the meta analysis of documented case reports, menthol can be used safely if its contraindications for use are followed as with any other over the counter medications.

A New Convenient Method for the Resolution of 1, 1'-Binaphthalene-2, 2'-diol Via a Phosphite Using (-)-Menthol as Resolving Agent

Menthol reacts with phosphorus trichloride to afford menthyl phosphorodichloridite 2, which further reacts with racemic 1, 1-binaphthalene-2, 2-diol to give phosphite (+)-3 in the presence of triethylamine. (+)-3 can be easily separated by fractional crystallization to form the crystal (+)-(S)-3 and the mother liquor (-)-(R)-3. Then both the crystal and the mother liquor are treated with AcOH-H2O to obtain enantiomeric pure (-)-(S)-1 and (+)-(R)-1 respectively, with enantiomeric excess up to 99.7%.

Gold Determination by Electrothermal Atomic Absorption Spectrometry After Preconcentration Using Natural Deep Eutectic Solvent Based on Menthol and Camphor

A novel analytical procedure for the determination of gold by electrothermal atomic absorption spectrometry combined with selective liquid-liquid extraction by natural deep eutectic solvents(NADESs)is presented.The extraction ability of the NADESs prepared using menthol,thymol and camphor toward gold in hydrochloric acid solutions was studied.The extraction efficiency was improved by optimizing the parameters including the composition of the NADES s,the volume ratio of organic and aqueous phases,kinetics,and acidity of the solution.Quantitative determination of gold was carried out by electrothermal atomic absorption spectrometry directly in the NADES s phase dissolved in isopropyl alcohol.The extraction recovery of gold from 1 mol/L HCl with the NADESs based on menthol and camphor mixed in a molar ratio 1:1 was 99.7%at an enrichment factor of 100.The limits of detection and quantification of the proposed procedure were 1μg/L and 3.3μg/L,respectively,with a relative standard deviation of less than 5%.The developed procedure was applied for determination of gold in the certified reference material of ore,environmental and waste waters.

鼻吸能量棒中挥发性成分的GC-MS法检验

鼻吸能量棒在中小学生中的风靡引起社会各界的普遍关注和极大担忧,对其成分进行检验可为明确其是否具有身体危害性提供依据。利用固相微萃取结合气相色谱-质谱法(GC-MS)对收集到的15个品牌21种不同气味的30个鼻吸能量棒样品进行检验,共检出69种化合物,除包装标明的樟脑、冰片、薄荷脑所含有的左旋樟脑、右旋樟脑、龙脑、异龙脑、薄荷醇等主要成分外,还检出化妆品行业常用溶剂C11、C12、C13、C16的异构烷烃和丰富的烯烃、酯类、醇类、醛类等植物精油、合成香料原料及中间体成分。对相同品牌不同气味、不同品牌相同气味的鼻吸能量棒检出成分进行综合分析和分类比对,结果表明,鼻吸能量棒成分复杂,含量各异,且与包装标示不符,长期滥用能够危害人的身体健康,加之使用方式有诱导吸毒的负面示范效应,急需规范整治。

Menthol-modified casein nanoparticles loading 10-hydroxycamptothecin for glioma targeting therapy

Chemotherapy outcomes for the treatment of glioma remains unsatisfactory due to the inefficient drug transport across the blood–brain barrier(BBB) and insufficient drug accumulation in the tumor region. Although many approaches, including various nanosystems, have been developed to promote the distribution of chemotherapeutics in the brain tumor, the delivery efficiency and the possible damage to the normal brain function still greatly restrict the clinical application of the nanocarriers.Therefore, it is urgent and necessary to discover more safe and effective BBB penetration and gliomatargeting strategies. In the present study, menthol, one of the strongest BBB penetration enhancers screened from traditional Chinese medicine, was conjugated to casein, a natural food protein with brain targeting capability. Then the conjugate self-assembled into the nanoparticles to load anti-cancer drugs.The nanoparticles were characterized to have appropriate size, spheroid shape and high loading drug capacity. Tumor spheroid penetration experiments demonstrated that penetration ability of mentholmodified casein nanoparticles(M-CA-NP) into the tumor were much deeper than that of unmodified nanoparticles. In vivo imaging further verified that M-CA-NPs exhibited higher brain tumor distribution than unmodified nanoparticles. The median survival time of glioma-bearing mice treated with HCPT-MCA-NPs was significantly prolonged than those treated with free HCPT or HCPT-CA-NPs. HE staining ofthe organs indicated the safety of the nanoparticles. Therefore, the study combined the advantages of traditional Chinese medicine strategy with modern delivery technology for brain targeting, and provide a safe and effective approach for glioma therapy.

天然薄荷醇改性聚丙烯酸酯防细菌黏附剂的制备及其在棉织物中的应用

利用天然小分子薄荷醇(MT)的立体防细菌黏附功能,通过酯化反应将其接枝到丙烯酸酐(AC)上,继而聚合生成新型含MT防细菌黏附侧链的聚丙烯酸酯共聚物[P(MAC-co-AA)]。采用浸轧法处理棉织物,赋予棉织物优良的防细菌黏附效果。结果表明,当MT和AC物质的量比为2∶1,反应温度为70℃,反应时间为5 h时,P(MAC-co-AA)酯化率高达70.9%,对大肠杆菌和金黄色葡萄球菌的防细菌黏附效果最好。相比MT,P(MAC-co-AA)的最大分解温度由130℃提高到252℃,其热稳定性大幅提升。当P(MAC-co-AA)整理液用量为20 g/L时,P(MAC-co-AA)整理棉织物对大肠杆菌和金黄色葡萄球菌的防细菌黏附率高达99.9%。

静电纺丝技术制备料香包埋材料及其性能研究

本研究针对加热卷烟滤嘴料香挥发性强、有效释放率低的问题,利用壳聚糖和聚己内酯通过静电纺丝和加热混合包埋技术,成功制备了新型料香包埋材料.通过红外光谱、热重分析和气相色谱等测试,评估了该材料的结构、留着率、释放性能及稳定性.结果表明,该材料对薄荷醇的负载率高达59.72%,常温留着率达78.58%,抽吸时的释放率超过85%,在14 d稳定性测试中,薄荷醇留存率较晶体形态提高15%.细胞实验进一步验证了其高生物相容性和低浓度依赖性的优势.这一研究为提升加热卷烟滤嘴的香料释放效率和感官品质提供了新策略.

薄荷醇在加热卷烟中的迁移行为研究

目的探究卷烟中加香香味物质在烟支中的迁移行为。方法设计并制备7组薄荷型加热卷烟样品,通过定期分析烟支各段中薄荷醇相对质量来考察其迁移行为。结果随着贮存时间的延长,3种贮存条件下烟支各段中薄荷醇相对质量呈现不同幅度的变化,其中冷藏条件下相对质量变化幅度小于其他2种条件,更利于样品的贮存。同一贮存条件下,烟支各段中香精施加量影响其相对质量的变化趋势及幅度,当该段香精施加量越多时,其相对质量呈现降低趋势且降低幅度越大,反之则呈现升高趋势且升高幅度越大。通过动力学拟合可知,烟支各段中薄荷醇的迁移行为符合伪一级动力学方程,其较好地描述了薄荷醇在烟支中的迁移过程。结语研究为探索加香香味物质在卷烟中的迁移行为提供了思路,可用于加香型卷烟产品的设计开发与贮存。

难度可调的仪器分析实验:气相色谱法测定风油精中薄荷脑、水杨酸甲酯等主要成分的含量

风油精是一种常见的家庭用药,其中含有桉油精、樟脑、薄荷脑、水杨酸甲酯及丁香酚5种主要成分。教师可根据实验条件及教学目标确定检测其中一种或多种成分。该研究推荐一个气相色谱测定风油精中各成分含量的实验。它既可以设计为高职院校的简单实验,也可设计为本科院校难度较高的实验;设计课时4h或8h,适合化学、药学或其他相关专业本、专科学生选用。

Fast Determination of Essential Oil from Dried Menthol Mint and Orange Peel by Solvent Free Microwave Extraction Using Carbonyl Iron Powder as the Microwave Absorption Medium

An improved solvent free microwave extraction, in which a kind of microwave absorption medium （carbonyl iron powder） was used, was applied to the extraction of essential oil from dried menthol mint and orange peel without addition of any solvent and pretreatment. It took much less time of extraction （30 min） than microwave-assisted hydrodistillation （90 min） and conventional hydrodistillation （180 min）. The kinds of chemical compositions in essential oil extracted by different methods were almost the same and such improved solvent free microwave extraction can be a feasible way in extraction of essential oil from dried plant materials.

薄荷醇对果蝇产卵驱避作用及毒杀效果

【目的】研究薄荷醇对常见几种果蝇Drosophila产卵的驱避作用,并通过后代存活率和发育历期及成虫死亡率以评价薄荷醇毒杀作用。【方法】应用产卵双向选择装置,在0.05%,0.1%和0.2%薄荷醇作用下检测果蝇的产卵选择性;利用双染料食物偏好实验检测薄荷醇对果蝇的摄食行为影响;利用产卵装置,检测薄荷醇对黑腹果蝇D.melanogaster的位置的影响;利用黑暗条件、摘除触角和前腿以及Orco 2突变体测定薄荷醇对黑腹果蝇产卵选择性的影响;并测定薄荷醇对黑腹果蝇后代存活率与发育历期的影响;测定薄荷醇对黑腹果蝇成虫寿命、奔跑速度和攀爬速度的影响;利用二氢乙锭(dihydroethidium,DHE)荧光染色技术,评估喂食1%薄荷醇3 d后黑腹果蝇成虫肠道内活性氧(reactive oxygen species,ROS)水平。【结果】薄荷醇对果蝇雌成虫产卵有驱避性,在0.05%,0.1%和0.2%薄荷醇作用下黑腹果蝇雌成虫的产卵指数分别为-0.42,-0.58和-0.98;铃木氏果蝇D.suzukii、雅库巴果蝇D.yakuba和拟暗果蝇D.pseudoobscura雌成虫对薄荷醇的产卵避性反应与黑腹果蝇雌成虫相同。在摄食过程中,黑腹果蝇及铃木氏果蝇成虫均对薄荷醇培养基产生明显排斥反应。薄荷醇培养基对黑腹果蝇成虫有明显的位置驱避性,0.05%,0.1%和0.2%薄荷醇处理下位置指数分别为-0.32,-0.44和-0.84。各个浓度的薄荷醇对黑暗环境和摘除前足的黑腹果蝇雌成虫仍然表现出显著的产卵驱避性,但在摘除黑腹果蝇成虫触角的条件下,薄荷醇对它们的产卵驱避性显著降低,0.05%,0.1%和0.2%薄荷醇作用下产卵指数分别为-0.04,-0.06和-0.26,薄荷醇对Orco 2突变体仍旧有产卵驱避性。与对照组相比,1%薄荷醇处理组黑腹果蝇成蛹和成虫羽化时间明显延长,分别延长了0.74和0.73 d,存活率明显下降,分别下降了63.2%和91.3%。随着薄荷醇浓度的增加黑腹果蝇成虫存活率呈现下降的趋势,且明显降低其奔跑和攀爬速度,即薄荷醇降低了亲代黑腹果蝇的适合度。1%薄荷醇处理3 d显著提升了黑腹果蝇成虫肠道内的ROS水平。【结论】薄荷醇通过嗅觉介导了果蝇的产卵避性反应,且薄荷醇降低了后代和亲代的适合度和存活率。

L-薄荷基甲酸的分离和纯化

寻找一种适合工业化分离L-薄荷基甲酸与其杂质新薄荷基甲酸的方法。试验采用薄荷基甲酸盐结晶法、胺盐结晶法、碱性水相通气(二氧化碳)法、弱碱提纯法,比较其分离纯化L-薄荷基甲酸的效果。结果显示,碱性水相通气(二氧化碳)法、弱碱提纯法对分离薄荷基甲酸杂质有效果。经优先比较,弱碱提纯法联合溶剂结晶法操作简便、产物纯度高、收率高,对工业化生产有一定的参考价值。

基于HS-GC-Orbitrap联用定性与定量测定活血止痛膏挥发性成分

目的建立活血止痛膏中挥发性成分定性、定量检测方法。方法采用顶空进样-气相色谱-静电场轨道阱质谱(HS-GC-Orbitrap)技术进行分析。样品除去背膜,以乙腈为溶剂,顶空进样;以高纯氦气为载气,TG-5SILMS色谱柱,程序升温,恒压模式,电子轰击源(EI源),全扫描监测模式测定。结果可定性活血止痛膏中5味药的12个主要成分,同时定量测定樟脑、异龙脑、龙脑、薄荷脑、水杨酸甲酯和丁香酚等6个成分。结论研究建立的方法提升了活血止痛膏质量控制水平,操作简便。

薄荷挥发油的主要成分及其制剂质量控制的研究进展

薄荷挥发油具有抗炎、抗氧化、抗菌和抗病毒等药理作用,被广泛用于复方制剂中。本文对薄荷挥发油主要成分、提取方式、薄荷素油及其制剂质量控制的研究状况进行综述,为制剂中薄荷素油的质量控制研究提供参考。

气相色谱法测定清宣止咳颗粒中薄荷脑的含量

目的:建立测定清宣止咳颗粒中薄荷脑含量的气相色谱法。方法:采用DB-FFAP弹性石英毛细管柱(25 m×0.32 mm×0.50μm);FID检测器;载气:N_(2);流速1 mL/min,进样口温度200℃,检测器温度250℃;柱温:初始温度70℃,保持4 min,然后以10℃/min升温至120℃,保持5 min,再以5℃/min升温至180℃,保持2 min,最后以25℃/min升温至200℃,保持5 min;进样量1μL;分流比2∶1。结果:薄荷脑质量浓度在0.01~0.10 mg/mL范围内与峰面积呈良好线性关系(r=0.9985),平均回收率为99.9%(n=9,RSD=3.8%)。结论:本方法快速、简便,结果可靠、准确,重现性好,适用于清宣止咳颗粒中薄荷脑含量的测定。

薄荷醇对低压低氧诱导小鼠肺动脉高压的作用及机制研究

目的 探讨薄荷醇对低压低氧诱导小鼠肺动脉高压的作用和机制。方法 健康雄性10~12周C57小鼠、瞬时受体电位通道M8基因敲除(TRPM8-/-)小鼠各40只,分为对照组、薄荷醇组、低压低氧组、低压低氧+薄荷醇组,超声测量肺动脉加速时间(PAT)和肺动脉射血时间(PET),右心导管测量右心室收缩压(RVSP),计算右心室肥厚指数(RVHI),观察肺小动脉重构(<100μm)情况,Western blot检测Krüppel样因子4(KLF-4)和增殖细胞核抗原(PCNA)蛋白表达。肺动脉平滑肌细胞(PASMCs)经低氧(3%氧浓度)、低氧+薄荷醇(100μmol·L^(-1))处理,测定增殖和迁移能力。结果 薄荷醇处理野生型小鼠后,PAT和PAT/PET比值增加(P<0.05),RVSP和RVHI降低(P<0.05),同时肺小动脉增厚和管腔狭窄程度减轻(P<0.05),KLF4表达增加(P<0.05)、PCNA表达降低(P<0.05);薄荷醇处理TRPM8-/-小鼠后,PAT、PAT/PET、RVSP、RVHI、KLF4、PCNA表达和肺血管重构均未见明显改变(P>0.05)。薄荷醇干预PASMCs后增殖、迁移能力下降(P<0.01、P<0.05)。结论薄荷醇可能通过TRPM8抑制PASMCs增殖、迁移,改善低压低氧诱导的小鼠肺血管重构和肺动脉高压,其机制可能与上调KLF4表达有关。