Antioxidant activity of propolis: role of caffeic acid phenethyl ester and galangin

Propolis, a natural product produced by the honeybee, has been used for thousands of years in folk medicine for several purposes. The extract contains amino acids, phenolic acids, phenolic acid esters, flavonoids, cinnamic acid, terpenes and caffeic acid. It possesses several biological activities such as antiinflammatory, immunostimulatory, antiviral and antibacterial. The exact mode of physiological or biochemical mechanisms responsible for the medical effects, however, is yet to be determined. In this work, we have investigated the antioxidant activity of a propolis extract deprived of caffeic acid phenethyl ester (CAPE). In addition, the activity of CAPE and galangin was also examined. Propolis extract (with and without CAPE) and its active components showed a dose-dependent free radical scavenging effect, a significant inhibition of xanthine oxidase activity, and an antilipoperoxidative capacity. Propolis extract with CAPE was more active than propolis extract without CAPE. CAPE, used alone, exhibited a strong antioxidant activity, higher than galangin. The experimental evidence, therefore, suggests that CAPE plays an important role in the antioxidant activity of propolis.     

The role of the phenethyl ester of caffeic acid (CAPE) in the inhibition of rat lung cyclooxygenase activity by propolis

In this study we investigated the effect of an ethanolic extract of propolis, with and without CAPE, and some of its components on cyclooxygenase (COX) activity. Propolis (0.00003-0.03%) significantly and concentration-dependently inhibited COX activity from lung homogenate of saline- or LPS-treated rats. Same results were obtained with CAPE (0.1-100 microM). COX activity from lung homogenate of saline- or LPS-treated rats was also inhibited by galangin (0.1-100 microM), although the inhibition induced by the lowest concentration was not significant. Caffeic, ferulic, cinnamic and chlorogenic acids and pinocembrin, (0.1-100 microM) did not affect COX activity. The inhibition curves showed that CAPE and propolis were equipotent inhibitors, whereas galangin was significantly (P<0.001) less potent than propolis and CAPE. In order to better investigate the role of CAPE, we tested the action of an ethanolic extract of propolis (0.00003-0.03%) without CAPE. This extract significantly and concentration-dependently inhibited COX activity from lung homogenate of saline- or LPS-treated rats, however, it resulted to be approximately 10 times less potent than the extract containing CAPE. The analysis of the inhibition curves of the extract with and without CAPE showed a significant (P<0.001) difference. These results suggest that both CAPE and galangin contribute to the overall activity of propolis, CAPE being more effective.     

In vitro permeation through porcine buccal mucosa of caffeic acid phenetyl ester (CAPE) from a topical mucoadhesive gel containing propolis

Recent studies have shown that propolis has on the oral cavity appreciable antibacterial, antifungal and antiviral actions, as well as anti-inflammatory, anaesthetic and cytostatic properties. In light of these studies, an assessment of the diffusion and permeation of caffeic acid phenetyl ester (CAPE) through porcine buccal mucosa was considered useful as a possible application in the stomatological field. To do so, a mucoadhesive topical gel was prepared to apply to the buccal mucosa. The gel was formulated in such a way as to improve the solubility of the propolis, conducting to an increase of the flux. The mucosal permeation of CAPE from the formulation was evaluated using Franz cells, with porcine buccal mucosa as septum between the formulation (donor compartment) and the receptor phase chamber. The diffusion through the membrane was determined by evaluating the amount of CAPE present in the receiving solution, the flux and the permeation coefficient (at the steady state) in the different formulations at set intervals. Qualitative and quantitative determinations were done by HPLC analysis. From the results, CAPE allowed a high permeability coefficient in comparison to the coefficient of other molecules, as expected from its physical-chemical structure. Moreover, the developed gel improved the CAPE flux approximately 35 times more with respect to an ethanol solution formulated at the same gel concentration. The developed gel was also tested in order to evaluate the mucoadhesive behaviour and comfort in vivo on 10 volunteers in a period of 8 h. The in vivo evaluation of mucoadhesive gel revealed adequate comfort and non-irritancy during the period of study and it was well accepted by the volunteers.     

Antisense expression of a caffeic acidO-methyltransferase ofStylosanthes humilis in transgenic poplar: Effect of expression onO-methyltransferase activity and lignin composition

Poplar (Populus tremula) was transformed with a construct carrying an antisense caffeic acidO-methyltransferase (COMT) cDNA (pOMT8) from a tropical pasture legume,Stylosanthes humilis. pOMT8 shows 83% overall homology to the corresponding COMT gene (pPCLA) of poplar. Of the 200 putatively-transformed plants regenerated on selective media after co-cultivation of poplar stem explants withAgrobacterium tumefaciens harbouring a CaMV 35S-antisensepOMT8 construct, a subset of 20 plants were randomly chosen for further analysis. PCR and Southern blot analysis demonstrated the stable integration of T-DNA into the genome of these plants. Antisense expression ofpOMT8 resulted in reductions in total COMT activity in the majority of the transgenic plants with the lowest total COMT activities (61–70% of untransformed control plants) being observed in four transgenic plants. The composition of lignin in transgenic plants was also changed, as detected by reductions in the content of syringyl units using infrared spectroscopy. However, no changes were found in the amount of insoluble lignin in transgenic plants as compared to untransformed control plants. These results indicate the potential of thepOMT8 gene to partially suppress COMT activity and modify the composition of lignin in transgenic poplar. This work was partly supported by General Management of Turkish Pulp and Paper Mills.     

Effect of Semecarpus anacardium nut milk extract on rat serum alpha-fetoprotein level in aflatoxin B1-mediated hepatocellular carcinoma

An increased level of serum alpha-fetoprotein is observed in aflatoxin B₁ (AFB₁)-induced hepatocellular carcinoma (HC) in rats. Semecarpus anacardium nut milk extract (200 mg/kg, p.o., for 14 days) significantly reduced serum alpha-fetoprotein levels within the normal range, suggesting an antitumour activity against AFB₁-induced HC.     

Contractile effect of the aqueous extract of Psidium guajava leaves on aortic rings in rat

Aqueous leaves extract of Psidium guajava significantly and dose-dependently (0.25-2 mg/ml) contracted aorta rings. The effect was evaluated also in presence of nifedipine and phentolamine. The sensitivity of the aortic rings to cumulative doses of P. guajava was significantly enhanced in the presence of phentolamine suggesting that the effect of P. guajava was to a large extent mediated by activation of alpha-adrenoceptor and to a lesser extent by acting via calcium ion channel.     

Effect of Garcinia cambogia extract on serum leptin and insulin in mice

In this study we examined the effects of 3.3% Garcinia cambogia extract on 10% sucrose loading in mice for 4 weeks. Treatment was found to have no effect on body weight, fat pad weight or serum glucose level. On the other hand, serum total cholesterol, triglycerides, NEFA were observed. Levels of serum insulin and leptin, as well as the leptin/WAT ratio, were lower in the treated mice than in the control. These findings suggested that G. cambogia extract efficiently improved glucose metabolism and displayed leptin-like activity.     

Myorelaxant and antispasmodic effects of the aqueous extract of Mitragyna inermis barks on Wistar rat ileum

Mitragyna inermis is used in the Senegal traditional medicine for treating stomach and intestinal disorders. At concentrations of 0.5, 0.75 and 1 mg/ml, the aqueous extract of M. inermis bark (AEMIB) significantly induced a decrease of the ileal basal tonus, respectively, from 37+/-1, 51+/-1 and 75+/-2% (P<0.05; n=5), compared to the baseline values. As well as atropine, AEMIB inhibited submaximal contractions induced by 0.01 mg/ml ACh with IC(50) value of approximately 0.75 mg/ml (n=5). These results show that AEMIB possesses both myorelaxant and antispasmodic actions in the ileum. This may justify the pharmacological basis for the popular use of Mitragyna for the treatment of gastrointestinal disorders.     

Effect of a standardized extract of red orange juice on proliferation of human prostate cells in vitro

A standardized extract of red orange juice (ROE) was shown to inhibit proliferation of fibroblast and epithelial prostate cells. These data suggest that the antiproliferative properties of ROE cannot be ascribed to cytotoxic effect and highlight its potential usefulness in the management of benign prostatic hyperplasia.     

Estimation of the sulfur ester content of cellulose nanocrystals prepared by sulfuric acid hydrolysis: a reproducible and fast infrared method

A fast and reproducible method for estimating the sulfur ester content of cellulose nanocrystals (CNCs) prepared by a pilot plant (Alberta Innovates Technology Futures—Alberta, Canada) is discussed. CNCs from sulfuric acid hydrolysis form electrostatically stabilized suspensions because of the introduction of sulfate ester groups onto the surface of the crystallites during the chemical production. The surface charge of the crystals and indirectly the sulfur ester content has implications when considering several applications. In the past, tedious and time-consuming methods such as X-ray photoelectron spectroscopy, X-ray diffraction, and elemental analysis have been used to estimate the sulfur content of CNCs. As of late, conductometric titrations have surpassed these techniques for estimating the sulfur content of CNC. In this communication, a technique is explored that is specific, fast, and reproducible across a number of samples for determining the quantity of C–O–S linkages in CNC samples. The method is based on integrating key peaks characteristic of sulfur functionalities obtained via Fourier transform infrared spectroscopy. The samples were analyzed as obtained, and no time was needed for extra sample cleanup prior to analysis. Finally, good correlation was obtained between the results obtained for the different samples and comparable to the results obtained from the widely used conductometric method.     

Effect of alcoholic extract of Ayurvedic herb Tinospora cordifolia on the proliferation and myeloid differentiation of bone marrow precursor cells in a tumor-bearing host

The present study investigates the effect of in vivo administration of alcoholic extract of Tinospora cordifolia whole plant (ALTC) on the proliferation and myeloid differentiation of bone marrow hematopoietic precursor cells in mice bearing a transplantable T cell lymphoma of spontaneous origin designated as Dalton's lymphoma (DL). BMC obtained from ALTC administered DL-bearing mice showed an enhanced BMC proliferation and colony forming ability in vitro in response to L929 conditioned medium as a source of colony stimulating factor (CSF). The number of granulocyte-macrophages colony (CFU-GM) was predominantly higher in the cultures of BMC obtained from ALTC administered mice as compared to mice injected with PBS alone. An increase in the count of bone marrow derived macrophages (BMDM) from ALTC administered mice was also observed along with an increase in the count of tumor associated macrophages. The BMDM obtained from ALTC administered mice showed an enhanced response to signal of LPS for activation to produce IL-1 and TNF. This study indicates that the T. cordifolia can influence the myeloid differentiation of bone marrow progenitor cells and the recruitment of macrophages in response to tumor growth in situ.     

Inhibitory effect of a propolis on Di-n-Propyl Disulfide or n-Hexyl salycilate-induced skin irritation,oxidative stress and inflammatory responses in mice

PurposeThermal imaging has been utilised, both preclinically and clinically, as a tool for assessing inflammation. Psoriasis is a chronic inflammatory skin disease characterised by hyperkeratosis, dermal inflammatory infiltrate and increased angiogenesis. The aim of the present study was to assess the usefulness of thermography in psoriatic lesion regression after topical treatment with bee propolis, recognised as potent antioxidants and anti-inflammatory agents.MethodsWe monitored the inflammation process induced by irritants such as n-Hexyl salycilate (HXS) or Di-n-Propyl Disulfide (PPD) by histopatological assessment of the skin, thermographic scanning, total number of inflammatory cells in the peritoneal cavity, differential analysis of cells in the peritoneal cavity, macrophage spreading index, haematological and biochemical parameters, frequencies of micronucleated reticulocytes, lipid peroxidation and glutathione assay in the skin.ResultsTopically applied ethanolic extract of propolis (EEP) with HXS or PPD reduced the lipid peroxidation in the skin and total number of inflammatory cells in the skin and peritoneal cavity, functional activity of macrophages, the number of micronuclei in mouse peripheral blood reticulocytes and enzymatic activity of ALP and AST.ConclusionThese results demonstrate that topical application of EEP may improve psoriatic-like skin lesions by suppressing functional activity of macrophages and ROS production. Taken together, it is suggested that EEP can safely be utilised in the prevention of psoriasis-related inflammatory changes without causing any toxic effect.     

水杨酸对盐胁迫下大豆生长和渗透调节能力的影响

砂基培养大豆,盐胁迫下进行水杨酸处理,NaCl和SA处理的预定浓度分别为0 0(对照)、100 0、100 0.3、200 0、200 0.3mmol/L。结果表明:SA处理后提高盐胁迫下大豆Pro、SS、AA和叶绿素含量;增强根系活力、硝酸还原酶(NR)活性。综合各项生长和生理指标表明,SA处理有利于增加渗透调节能力,减缓水分胁迫,缓解盐害;且SA对NaCl 100mmol/L处理的大豆生长缓解效应优于NaCl200mmol/L胁迫的。     

干旱胁迫对马尾松苗木脯氨酸及游离氨基酸含量的影响

[目的]证实脯氨酸及游离氨基酸在马尾松苗木抵御干旱胁迫中积累并发挥作用,揭示其在不同胁迫时期含量的变化规律。[方法]选择5个种源马尾松苗木,设计3种水分梯度,开展为期54d干旱胁迫试验,分别于胁迫处理18d、36d和54d后测定苗木针叶内脯氨酸及游离氨基酸含量。[结果](1)脯氨酸及游离氨基酸含量在干旱胁迫18d后均无明显变化规律,但脯氨酸含量在干旱胁迫54d后、游离氨基酸含量在干旱胁迫36d后均呈随胁迫程度加深而上升的变化。(2)随胁迫时间的延长,脯氨酸的平均含量呈先降后升趋势,而游离氨基酸的平均含量呈先升后降趋势。(3)脯氨酸和游离氨基酸含量在不同种源苗木内的分布差异显著。在5个种源中,脯氨酸平均含量以浙江江山和湖南汝城种源排最高和最低,分别为91.33μg/g(DW)和69.16μg/g(DW);游离氨基酸平均含量以广东信宜和湖北大悟种源排最高和最低,分别为1 597.88μg/g(DW)和1 279.04μg/g(DW)。[结论]干旱胁迫下,脯氨酸及游离氨基酸均能在苗木体内合成,使苗木适应干旱环境而继续生长。     

Differential behavior between acacia and Japanese larch woods in the formation and decomposition of hexenuronic acid during alkaline cooking

The effects of anthraquinone (AQ) and polysulfide (PS) on the hexenuronic acid (HexA) content of pulp during kraft cooking were studied using Acacia mearnsii (acacia) and Larix leptolepis (Japanese larch) sapwood. In contrast to the results of cooking Japanese larch at an H-factor of 1200, the HexA contents of acacia pulp with a kappa number of 20 at an H-factor of 291 did not differ greatly between the kraft, kraft-AQ, and PS-AQ cooking methods, although the hydroxide ion concentration in the acacia cooking liquor decreased on the addition of AQ or sulfur. To explain this difference, we studied the behavior of the formation and degradation of HexA during alkaline cooking of glucuronoxylan from cotton linter, which was cooked with 1.0 and 2.0 mol/l NaOH. The relationship between HexA content and H-factor during alkaline cooking of glucuronoxylan was clarified. The amount of HexA and its rate of decomposition were higher in the 2.0 mol/l solution than in the 1.0 mol/l solution. At a low H-factor similar to that for hardwood cooking, HexA content increased to a maximum level and then started to decrease at high hydroxide ion concentrations such as 2.0 mol/l, whereas it slowly decreased at low hydroxide concentrations such as 1.0 mol/l. At an H-factor of around 450, the HexA formation/degradation curve for 1.0 mol/l of hydroxide crossed the decomposition curve for 2.0 mol/l of hydroxide. Therefore, it was shown that at a low H-factor, a decrease in hydroxide ion concentration during acacia wood cooking had little effect on the HexA content of pulp.     

氨基酸活性液肥对葡萄园土壤肥力及产量和品质的影响

日光温室红地球葡萄分别施用绿能牌、绿丰牌和冠菌牌3种氨基酸活性液肥后,对比分析了不同肥料对葡萄土壤微生物种群数量、土壤肥力、产量和品质的影响。结果表明:绿能牌氨基酸活性液肥处理后土壤有益微生物亚硝化细菌、硝化细菌、乳酸菌、纤维素分解细菌和放线菌的数量,土壤有机质含量,葡萄果实单粒重、可溶性固形物含量、Vc含量和产量最高,分别为1.30×104个/g干土样、1.70×104个/g干土样、9.10×104个/g干土样、6.10×104个/g干土样、27.00×104个/g干土样、49.90g/kg、18.06g、18.79%、148.08μg/g和33065.92kg/hm2,土壤有害微生物反硝化细菌、霉菌,果实可滴定酸含量最低,分别为13.00×104个/g干土样、0.03×104个/g干土样和0.29%,且果实色泽为深红。在日光温室红地球葡萄栽培中可施用氨基酸来提质增产。     

采收期对3种笋用竹竹笋营养及氨基酸含量的影响

为探明不同采笋期对竹笋品质及营养成分的影响,对红哺鸡竹(Phylostachys iridescens)、白哺鸡竹(Ph.dulcis)和黄秆乌哺鸡竹(Ph.vivax'aureocaulis')3种笋用竹不同采笋期竹笋蛋白质、粗纤维、还原糖、灰分含量和氨基酸质量分数进行了测定.结果表明,3种笋用竹竹笋蛋白质干基含量均在310 g/kg以上,红哺鸡竹还原糖干基含量为107.0—188.1 g/kg,而白哺鸡竹和黄秆乌哺鸡竹还原糖含量分别为66.1—117.2,72.1—121.0 g/kg.3种笋用竹竹笋中粗纤维含量为43.0—84.2 g/kg,脂肪为26.0—36.0 g/kg.采收期异同不仅影响竹笋的粗纤维和灰分含量,也会影响到竹笋中蛋白质、脂肪、还原糖,但不同竹种的含量变化有所不同.红哺鸡竹竹笋中脂肪、蛋白质含量随采集时间的推后含量递减,但还原糖含量递增,而白哺鸡竹和黄秆乌哺鸡竹竹笋中脂肪、蛋白质含量随采集时间的变化不明显.3种笋用竹竹笋氨基酸总量(T)变化在13.06—35.4 g/kg,E/T值均在33.0以上.红哺鸡竹竹笋的T值随采收期的延后含量增加,而白哺鸡竹和黄秆乌哺鸡竹竹笋的T值则呈现出随采收期的延后含量递减,儿童必需氨基酸总量(CE)呈现类似的变化.竹笋营养成分和氨基酸的时令变化对于指导竹笋采集和竹林经营具有一定指导意义.     

Effect of the helix angle of router bits on chip formation and energy consumption during milling of solid wood

The effect of the helix angle of a router bit on chip formation and electric energy per volume (specific energy) under different feed speeds and cutting depths during the milling of maple and China fir by a computer numerically controlled (CNC) router was investigated. The peripheral cutting edge of router bits were custom-made at helix angles of 0°, 2°, 4°, 6°, and 8°. The feed speed varied from 600 to 4800mm/min, and the depths of cut were set at 1,2,3,4, and 6mm. The chips were classified by sieving into a flake type, a splinter type (5 and 10 mesh), a flow type (20 and 40 mesh), and a granule type (< 40 mesh). As the feed speed and the cutting depth increased for the five router bits, more chips of the flake type and the splinter type were produced. However, the number of granule-type chips under the larger helix angle was reduced. The energy per volume removed (specific energy) increased with the feed speed and the depth of cut while milling maple and China fir. More specific energy per cubic centimeter was consumed under the lower feed speeds and the smaller depth of cut. The specific energy can be expressed as a negative power function of the feed speed or the cutting depth for maple and China fir.     

贵州麻阳河黑叶猴家域及影响因素初探

通过对麻阳河自然保护区国家一级重点保护野生动物－－黑叶猴（Presbytis francoisi）家域及影响因素的调查研究表明：该区黑叶猴家域受自然及人为干扰程度较大；主食植物相对丰富，但存在与牛羊抢夺食物的现象；黑叶猴种群数量受人为干扰严重，建议采取有效措施保护和改善该区黑叶猴生存环境。     

山杏叶桦木酸、齐墩果酸和熊果酸的研究

我国山杏资源十分丰富,是绿化荒山的优良树种。采用HydersirBDSC18色谱柱（150×4．6mm,5μm）,流动相体积比为90：10的0．3‰硫酸甲醇溶液一3‰硫酸水溶液,检测波长210nm,建立了山杏叶中三萜酸测定的高效液相色谱法。结果表明：桦木酸、齐墩果酸与熊果酸的浓度在30～2000μg／mL（r桦=0．9971,r齐=0．9986,r熊=0．9978）范围内与色谱峰面积呈良好线性关系;平均加标回收率分别为99．9％、101．1％和98．9％。以山杏叶为材料,采用高效液相色谱法和紫外可见分光光度法分别对山杏叶中的三萜酸成分进行分析,结果表明,山杏叶富含三萜酸,落叶期山杏叶中总三萜酸（17078#g／g）、桦木酸（1842μg／g）、齐墩果酸（2536μg／g）和熊果酸（5706μg／g）含量均高于非落叶期。本研究首次建立了山杏叶中桦木酸、齐墩果酸和熊果酸同时测定的反向高效液相色谱法（HPLC）,发现落叶期山杏叶富含三萜酸,为山杏叶综合开发利用提供了基础数据。