Green Synthesis and Antibacterial Properties of Silver Nanoparticles from Eugenia uniflora Fruit Extract

The synthesis of nanoparticles by biological methods using microorganisms, enzymes, or plant extracts has been suggested as a possible ecofriendly alternative to chemical and physical methods that involve the use of harmful reducing agents. Green synthesis of silver nanoparticles (AgNPs) was achieved using Eugenia uniflora ripe fruit extract, which was characterized by phytochemical screening revealing the presence of polyphenols (quinones, flavonoids, and tannins), reducing compounds, and terpenes. These excellent antioxidants reduced silver nitrate to give the AgNPs, which were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and ζ potential analysis. The diameter of the AgNPs ranged from 10.56 ± 1.2 nm to 107.56 ± 5.7 nm. The antibacterial activity of the AgNPs was evaluated using a modification of the Kirby-Bauer technique with Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The inhibition halos were 11.12 ± 0.02 mm, 13.96 ± 0.07 mm, and 11.29 ± 0.76 mm, respectively. The synthesis using E. uniflora is an ecofriendly and low cost method of obtaining silver nanoparticles that could be used in health sciences because of their activity against bacteria with antibiotic resistance.

LC–MS characterization, anti-kinetoplastide and cytotoxic activities of natural products from Eugenia jambolana Lam. and Eugenia uniflora

Objective: To evaluate the trypanocidal, leishmanicidal and cytotoxic activity of Eugenia jambolana(E. jambolana) and Eugenia uniflora(E. uniflora) extracts and fractions.Methods: The products were characterized by LC–MS. Antiparasitic assays were performed and cytotoxicity was evaluated in fibroblastos. In vitro assays were performed using spectrophotometric evaluation. All assays were performed in thrice.Results: The results showed that the extracts and the tannic fraction from E. jambolana inhibited 100% of the epimastigote lines. The ethanolic extract was the most efficient in all concentrations tested against the three parasite strains. In the cytotoxicity assay the flavonoid fraction showed low toxicity. All E. uniflora samples showed cytotoxicity at the highest concentration tested, but the extract showed no toxic effect on the fibroblasts at the lowest concentration. The flavonoid and tannic fractions were more efficient against Leishmania braziliensis promastigotes compared to the extract. However, the extracts and the tannic fraction were more effective against Leishmania infantum strains. The effect on epimastigote cells was observed at all concentrations tested, with all E. uniflora samples. However, the samples were more effective at the highest concentration, where there was inhibition in 100% of the Trypanosoma cruzi strains.Conclusions: The species E. jambolana and E. uniflora presented antiparasitic activity against all tested parasite strains, indicating that these species can serve as an alternative therapy as they were efficient in the tests performed. The E. uniflora extract and the E. jambolana flavonoid fraction presented a low cytotoxicity, opening the floor for new biological studies.

Sex-specific effects of Eugenia punicifolia extract on gastric ulcer healing in rats

AIM To evaluate the sex-specific effects of a hydroalcoholic extract from Eugenia punicifolia(HEEP) leaves on gastric ulcer healing.METHODS In this rat study involving males, intact(cycling) females, and ovariectomized females, gastric ulcers were induced using acetic acid. A vehicle, lansoprazole, or HEEP was administered for 14 d after ulcer induction. Body weight was monitored throughout the treatment period. At the end of treatment, the rats were euthanized and the following in vivo and in vitro investigations were performed: macroscopic examination of the lesion area and organ weights, biochemical analysis, zymography, and evaluation of protein expression levels. Additionally, the concentration-dependent effect of HEEP was evaluated in terms of subacute toxicity and cytotoxicity.RESULTS Compared to the vehicle, HEEP demonstrated a great healing capacity by substantially reducing the ulcerative lesion area in males(52.44%), intact females(85.22%), and ovariectomized females(65.47%), confirming that HEEP accelerates the healing of acetic acidinduced gastric lesions and suggesting that this effect is modulated by female sex hormones. The antiulcer effect of HEEP was mediated by prostaglandin E2 only in male rats. Overall, the beneficial effect of HEEP was the highest in intact females. Notably, HEEP promoted the expression of vascular endothelial growth factor(intact vs ovariectomized females) and decreased the expression of Caspase-8 and Bcl-2(intact female vs male or ovariectomized female). Additionally, HEEP enhanced fibroblast proliferation and migration into a wounded area in vitro, confirming its healing effect. Finally, no sign of subacute toxicity or cytotoxicity of HEEP was observed.CONCLUSION In gastric ulcers, HEEP-induced healing(modulated by female sex hormones; in males, mediated by prostaglandin) involves extracellular matrix remodeling, with gastric mucosa cell proliferation and migration.

Safety evaluation of Eugenia jambolana seed extract

Objective:To evaluate the safety of ethanolic seed extract of Eugenia jambolana（EJSE） using acute and sub-chronic toxicity assays in Swiss albino mice as per Organisation for Economic Co-operation and Development（OECD） guidelines.Methods:Possible behavioral changes and lethality were observed in mice administered a single dose[1 000,2 000,3 000,4 000 or 5 000mg/kg body weight（BW）]of EJSE,Plasma levels of metabolic,hepatic,cardiac and renal function markers, electrolytes,blood count and histopathology of major organs were monitored in mice chronically treated with EJSE（1 000,2 000 or 3 000 mg/kg BW） for 28 days.Results:Since no mortality was recorded in the acute toxicity evaluation up to a dose of 5 000 mg/kg bodyweight of EJSE,50% lethal dose(LD50) was assumed to be 】5 000 mg/kg BW.In the sub-chronic toxicity evaluation, no adverse observations were recorded in mice administered with 2 000 mg/kg BW of EJSE; however at 3 000 mg/kg BW dose,moderately significant increase in the plasma levels of urea and creatinine was observed.Hence,the lowest observable adverse effect level（LOAEL） for EJSE was found to be 3 000 mg/kg BW and the no observable adverse effect level（NOAEL） was adjudged as 2 000 mg/kg BW.Conclusions:It can be concluded from this study that,orally administered EJSE is safe up to a10 fold higher dose than its reported therapeutic dose.

Effect of Eugenia winzerlingii Extracts on Bemisia tabaci and Evaluation of Its Nursery Propagation

The development of plant-derived products to control Bemisia tabaci Genn.(Hemiptera:Aleyrodidae)is an urgent need for production of horticultural crops.Plant extracts and essential oils of several species of the genus Eugenia(Myrtaceae)have shown insecticidal activity.In southern Mexico,leaf extracts from Eugenia winzerlingii showed nematicidal effect but its insecticidal properties have not been explored.Therefore,the objective of this study was to evaluate the insecticidal effect of aqueous and organic extracts from E.winzerlingii leaves on B.tabaci egg,nymph and adult stages,and else to explore its nursery propagation.Then,extracts of this species were obtained by maceration with different polarity solvents.Bioassays were carried out on Capsicum chinense leaves.Mortality assays showed that aqueous and total crude ethanol(TCE)extracts necrosed the eggs(LC50=0.21%w/v and 4.68 mg/mL,respectively),whereas hexane,ethyl acetate(ETA),residual ethanol and TCE extracts affected the nymphs(LC50=0.25-4.85 mg/mL).In adults,oviposition inhibition by free choice assay indicated that TCE and ETA extracts had major activity(EC50=14.62 and 27.86μg/cm2,respectively).On other hand,the sexual and vegetative propagation of E.winzerlingii showed that this species can be easily cultivated by seeds.In conclusion,extracts of E.winzerlingii leaves are highly effective in controlling B.tabaci.TCE extract,in particular,was toxic to three stages of B.tabaci.This plant could be a potential alternative to develop a novel botanical insecticide to manage this destructive pest.

Chemical Composition and Antibacterial Activity of the Essential Oils from Different Parts of <i>Eugenia caryophylata</i>, Thunb Grown in Amboina Island

This study aims to investigate the antibacterial activities of essential oils isolated from various parts (buds, leaves and stems) of Eugenia caryophylata. The essentials oils were distillated by steam distillation, and the isolated was analyzed by GC and GC-MS. Five components of each sample of oils (buds, leaves and stems) were identified. Main component in the bud are eugenol (75.30%), eugenyl acetate (20.93%) and β-caryophyllene (3.00%) and eugenol (82.97%), β-caryophyllene (12.84%) in leaf oil, while in stem oil eugenol (97.75%). The oils were tested for in vitro antimicrobial activities against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), the Gram-negative bacteria (Escherichia coli and Salmonella typhimurium). The essential oils of bud, leaf and stem oil show that antibacterial activity against Gram-positive and Gram-negative bacteria.

Laxative Effect of Eugenia Jambolana Crude Leaf Bud Extract

The therapeutic value of Eugenia jambolana Lam. commonly known as ‘Jamun’ has been recognized in different system of traditional medication for the treatment of different diseases and ailments. It contains several phytoconstituents belonging to category of alkaloids, glucosides, flavonoides and volatile oils. It has been reported as digestive, astringent to the bowels, anthelmintic, sore throat, bronchitis, asthma, thirst, biliousness, dysentery, blood purifier, ulcers and diabetes. There are few reports available on clinical uses of Eugenia jambolana in diabetes that have shown promising results. In south India ayurvedic practitioners were using the leaf buds of Eugenia jambolana to induce laxative effect and to clean up the intestinal contents before starting any medication. The result showed that of E. jambolana stimulates the contractile action of frog and mice through an acetylcholine-like mechanism and effectively stimulates gastrointestinal motility in mice and frogs. In this paper we have discussed the laxative effect of Eugenia jambolana leaf bud extract which was never reported scientifically.

Habitat components and population density drive plant litter consumption by Eudrilus eugeniae(Oligochaeta)under tropical conditions

The ingestion of organic and mineral materials by earthworms is a prominent functional role that has profound consequences for the decomposition and stabilization of soil organic matter.To investigate the litter consumption of the African nightcrawler earthworm Eudrilus eugeniae under different tropical conditions,we used DNA barcoding to identify specimens of E.eugeniae collected from sites across the Adamawa region in Cameroon,and studied the influence of habitat suitability(soil properties),soil moisture,litter type,and population density on litter consumption.A total of four litter consumption experiments were carried out using soils collected from refuse disposal sites,agricultural lands,and savannahs dominated by the Mexican sunflower Tithonia diversifolia.The results revealed that litter consumption significantly increased in the refuse disposal and agricultural soils as opposed to the Mexican sunflower(T.diversifolia)soil,a cow dung enriched substrate,and a sterile soil horizon from the savannah(P<0.05).The optimum moistures for litter consumption were between 24%and 50%.Litter type did not affect the consumption rate of the earthworms(P>0.05).We observed a general positive density-dependent consumption with litter mass loss increasing with increasing density.Our results suggest that E.eugeniae has a strong direct effect on the decomposition of plant materials than expected from previous estimations,and that litter consumption rates are determined by several habitat components and population density.

全球工业主义下“创客”的在华发生——评《中国的本土工业主义:化妆品帝国建立中的本土创新以及外来科技,1900—1940》

林郁沁的新著《中国的本土工业主义:化妆品帝国建立中的本土创新以及外来科技,1900—1940》通过研究陈蝶仙的生平对近代科学技术知识的在华传播做了具有特色的阐述,从总体格局上看,它属于全球工业主义下“创客”的在华发生。

乙醇熏蒸对巴西番樱桃保鲜工艺的研究

以中山市海枣椰农业科技有限公司引种栽培的巴西番樱桃为研究对象,以果实呼吸强度为考察指标,采用单因素试验和正交试验筛选最优熏蒸乙醇浓度、熏蒸时间、熏蒸温度。研究结果表明,熏蒸乙醇浓度250μL·L^(-1),熏蒸时间4.0 h、熏蒸温度40℃为最佳保鲜工艺,该条件对采后巴西番樱桃呼吸强度抑制效果最为显著。

丁香挥发油对小鼠皮肤影响的初步研究

目的:为了培养学生的科学素养能力,引导学生将科研课题“丁香挥发油对小鼠正常皮肤及破损皮肤的影响”设计成本科生初步研究性实验。通过考察丁香挥发油的皮肤刺激性,评价该挥发油的安全性。方法:参照《化妆品安全技术规范》(2015版),采用急性皮肤刺激性实验和多次给药皮肤刺激实验。结果:急性皮肤刺激性实验中,实验组小鼠正常皮肤和破损皮肤的皮肤反应平均积分值都为0;多次给药皮肤刺激实验中,实验组小鼠正常皮肤和破损皮肤的每天每只动物皮肤反应平均积分分别为0和0.31,以上各组积分均小于0.5,初步表明该挥发油为无刺激性。结论:广西产地的丁香挥发油对小鼠的正常皮肤和破损皮肤刺激性小,具有一定的安全性,展示了丁香一定的应用价值。该实验包含提取制备技术和急性皮肤刺激性实验的原理、操作,对本科生的客观实际分析能力和解决问题能力起到正向反馈的作用,以便为学生今后进行科学研究打下初步的基础。

公丁香挥发油化学成分的GC-MS分析

公丁香为桃金娘科植物丁香Eugenia caryophyllata的干燥花蕾.原植物系常绿乔木,主产于桑给巴尔、马达加斯加、斯里兰卡、印度尼西亚等地,我国南方已大量引种.作为中药,公丁香具有温中降逆和补肾助阳的功效,可用于治疗脾胃虚寒、呃逆呕吐、食少吐泻、心腹冷痛和肾虚阳痿[1,2].……

丁香总黄酮抗氧化活性研究

以2,6-二叔丁基-4-甲基苯酚(BHT)对照品、槲皮素对照品和丁香(Eugenia caryophyllata Thunb.)挥发油为对照,对丁香总黄酮还原力、清除1,1-二苯基-2-三硝基苯肼(DPPH·自由基)能力进行了评价。结果表明,丁香总黄酮有较好的抗氧化活性,其还原力略低于阳性对照BHT而高于丁香挥发油,清除DPPH·自由基能力则随浓度增大明显增强,浓度达到0.15、0.20 mg/mL时,其DPPH·自由基清除率分别超过丁香挥发油和阳性对照BHT。

肉桂等3种挥发油对苯甲酸透皮吸收的影响

目的 :研究肉桂油、高良姜油、丁香油对苯甲酸透皮吸收的影响。方法 :采用体外透皮双室扩散池和HPLC法 ,测定模型药物苯甲酸的累积渗透量 ,以考察不同浓度的肉桂油、高良姜油、丁香油对苯甲酸的促渗效果及挥发油与乙醇、丙二醇合用后的情况。结果 :肉桂油、丁香油、丁香酚、高良姜油对苯甲酸均具有一定的促渗作用 ,挥发油与乙醇、丙二醇合用 ,使苯甲酸的累积渗透量增大 ,但渗透系数减小。结论 :肉桂油、高良姜油。

超临界CO_2流体萃取-分子蒸馏提取丁香精油的研究

用超临界CO2流体萃取技术(SCDE)萃取丁香精油,然后用分子蒸馏技术(MD)进行精制,所得精油经气相色谱-质谱(GC-MS)分析并与传统提取方法比较。正交试验分析结果显示,SCDE最佳工艺条件为:萃取温度45℃、萃取压力12 MPa、解析温度50℃。SCDE得油率达到21.04%,经GC-MS分析共检测出22种成分,主要成分丁香酚GC含量为67.56%,经MD精制后,尽管丁香酚、β-石竹烯、乙酰基丁香酚3种有效成分的总含量与水蒸气蒸馏法和有机溶剂回流法相差不大,但精油中丁香酚提高至68.75%,精油色泽和流动性明显改善,品质明显提高。SCDE-MD技术萃取丁香精油的得油率为19.18%,高于水蒸气蒸馏法(11.38%)和正己烷回流法(17.40%),而且萃取时间短,色素、树脂含量低。

当归、丁香挥发油的促透皮吸收作用

目的研究当归、丁香挥发油的促透皮吸收作用。方法以丹参酮ⅡA、葛根素、人参皂苷Rg1为模型药物,测定这两种挥发油（0.5%、2%、5%）对小鼠离体皮肤的促透皮吸收作用。结果当归、丁香挥发油对丹参酮ⅡA和人参皂苷Rg1的促透皮吸收作用相当,与对照组相比,其增透倍数为2～17,前者对葛根素的促透皮吸收作用略大于后者。挥发油体积分数越高,渗透系数越大。结论当归、丁香挥发油可作为天然透皮吸收促进剂。

可见光及紫外光分光光度法测定丁香总黄酮含量的研究

目的研究可见光及紫外分光光度法测定丁香总黄酮含量的方法。方法可见光分光光度法是以芦丁为参照品,硝酸铝作显色剂,在510 nm波长测定总黄酮含量。紫外分光光度法是以芦丁为参照品,在359 nm波长测定总黄酮含量。结果可见光法平均回收率是99.46%,紫外光法是99.13%。RSD分别是1.15%和0.90%。结论紫外分光光度法是一种较理想的测定方法。

丁香对幽门螺杆菌的体外抑菌作用

目的考察丁香挥发油及丁香酚体外抑制幽门螺杆菌的活性。方法水蒸气蒸馏法提取丁香挥发油,采用高效液相色谱法测定挥发油丁香酚的含量。以氨苄西林为对照,体外法测定丁香挥发油、丁香提取挥发油后的水提取物及丁香酚对8种幽门螺杆菌菌株的最小抑菌浓度(MIC)。结果氨苄西林对8种幽门螺杆菌菌株的MIC范围为1.25～2.50μg.mL-1,丁香挥发油的MIC范围为5.00～10.00μg.mL-1,丁香酚的MIC范围为2.50～5.00μg.mL-1,丁香提取挥发油后的水提取物无抑菌作用。结论丁香抑制幽门螺杆菌的活性成分是其挥发油中的主要成分丁香酚。