Acaricidal activity and function of mite indicator using plumbagin and its derivatives isolated from Diospyros kaki Thunb. roots (Ebenaceae)

Acaricidal effects of materials derived from Diospyros kaki roots against Dermatophagoides farinae and D. pteronyssinus were assessed using impregnated fabric disk bioassay and compared with that of the commercial benzyl benzoate. The observed responses varied according to dosage and mite species. The LD50 values of the chloroform extract of Diospyros kaki roots were 1.66 and 0.96 microg/cm2 against D. farinae and D. pteronyssinus. The chloroform extract of Diospyros kaki roots was approximately 15.2 more toxic than benzyl benzoate against D. farinae, and 7.6 times more toxic against D. pteronyssinus. Purification of the biologically active constituent from D. kaki roots was done by using silica gel chromatography and high-performance liquid chromatography. The structure of the acaricidal component was analyzed by GCMS, 1H-NMR, 13C-NMR, 1H-13C COSY-NMR, and DEPTNMR spectra, and identified as plumbagin. The acaricidal activity of plumbagin and its derivatives (naphthazarin, dichlon, 2,3-dibromo-1,4-naphthoquinone, and 2-bromo-1,4- naphthoquinone) was examined. On the basis of LD50 values, the most toxic compound against D. farinae was naphthazarin (0.011 microg/cm2) followed by plumbagin (0.019 microg/cm2), 2- bromo-1,4-naphthoquinone (0.079 microg/cm2), dichlon (0.422 microg/ cm2), and benzyl benzoate (9.14 microg/cm2). Additionally, the skin color of the dust mites was changed from colorless-transparent to dark brown-black by the treatment of plumbagin. Similar results have been exhibited in its derivatives (naphthazarin, dichlon, and 2-bromo-1,4-naphthoquinone). In contrast, little or no discoloration was observed for benzyl benzoate. From this point of view, plumbagin and its derivatives can be very useful for the potential control agents, lead compounds, and indicator of house dust mites.     

Mite-control activities of active constituents isolated from Pelargonium graveolens against house dust mites

The mite-control activities of materials obtained from Pelargonium graveolens oil against Dermatophagoides farinae and D. pteronyssinus were examined using an impregnated fabric disk bioassay and were compared with those shown by commercial benzyl benzoate and N,N-diethylm- toluamide (DEET). Purification of the biologically active constituents from P. graveolens oil was done by silica gel chromatography and high performance liquid chromatography. The structures of the active components were analyzed by EI/MS, (1)H-NMR, (13)C-NMR, (1)H-(13)C COSYNMR, and DEPT-NMR spectra, and were identified as geraniol (C(10)H(18)O, MW 154.25, trans-3,7-dimethyl-2,6- octadien-1-ol) and beta-citronellol (C(10)H(20)O, MW 156.27, 3,7-dimethyl-6-octen-1-ol). Based on the LD50 values, the most toxic compound was geraniol (0.26 microg/cm(2)), followed by beta-citronellol (0.28 microg/cm(2)), benzyl benzoate (10.03 microg/ cm(2)), and DEET (37.12 microg/cm(2)) against D. farinae. In the case of D. pteronyssinus, geraniol (0.28 microg/cm(2)) was the most toxic, followed by beta-citronellol (0.29 microg/cm(2)), benzyl benzoate (9.58 microg/cm(2)), and DEET (18.23 microg/cm(2)). These results suggest that D. farinae and D. pteronyssinus may be controlled more effectively by the application of geraniol and beta-citronellol than benzyl benzoate and DEET. Furthermore, geraniol and beta-citronellol isolated from P. graveolens could be useful for managing populations of D. farinae and D. pteronyssinus.     

Clinical Significance of Skin Reactions to Mite Extracts in Children with Asthma

The mite Dermatophagoides pteronyssinus has been identified in dust from the houses of children in Birmingham suffering from asthma. Skin tests were carried out on 150 asthmatic children with extracts of D. pteronyssinus, of the related species D. farinae, of other mites found in house dust, and of crude house dust. Though positive reactions to D. pteronyssinus were obtained more frequently and were of greater size than those to the other extracts, it was considered that D. farinae is a suitable substitute for D. pteronyssinus for skin testing.In further tests on 302 asthmatic children with mite extracts and with extracts of allergens obtained commercially reactions to the former extracts were much more common than reactions to the latter.Major skin reactions (weals with diameter of 5 mm. or more) were present in 77% of children with a history of perennial asthma and house-dust sensitivity. Hence allergy to house-dust mites, particularly D. pteronyssinus, is of considerable importance in childhood asthma, and further study of the ecology and control of the mites in dust is desirable.     

山西省晋中市及周边地区螨虫分布状况和优势螨种的研究

目的 研究山西省晋中市及周边地区的尘螨种类和优势螨种.方法 以就诊于晋中市第一人民医院耳鼻喉科门诊的尘螨过敏患者为研究对象,从2009年12月至2011年10月对居住在晋中市及周边地区的30户家庭进行入户采集调查.采集尘样后经过分离,制片,最后进行鉴定.结果 共采集尘样196份,户尘螨占成螨总数的60.1％,粉尘螨占39.8％.通过对不同采集地点的调查结果显示,楼房的样本阳性率为35.8％,平房的样本阳性率为21.8％.通过对不同环境样本中螨密度的统计,枕头的螨密度最高,为166.7头/g.平均螨密度在全年有2个高峰期,分别是7-8月份和12～2月.结论 晋中市及周边地区的主要螨种为麦食螨科的户尘螨和粉尘螨,户尘螨为优势螨种.     

Acaricidal effects of herb essential oils against Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae) and qualitative analysis of a herb Mentha pulegium(pennyroyal)

This experiment was undertaken to screen the acaricidal effects of herb essential oils (pennyroyal, ylang ylang, citronella, lemon grass, tea tree, and rosemary) at different doses (0.1, 0.05, 0.025, 0.0125, and 0.00625 microliter/cm(2)) and exposure times (5, 10, 20, 20, 30 and 60 min) on house dust mites Dermatophgoides farinae and D. pteronyssinus. The most effective acaricidal components of pennyroyal (Mentha pulegium) were analyzed using a gas chromatography-mass spectrometer (GC-MS). Of these essential oils, the most effective was pennyroyal, which is composed essentially of pulegone (> 99%), at a dose of 0.025 microliter/cm(2), which at an exposure time of 5 min killed more than 98% of house dust mites. In the pennyroyal fumigation test, the closed method was more effective than the open method and maximum acaricidal effect was 100% at 0.025 microliter/cm(2), 60 min. The results show that herb essential oils, in particular, pennyroyal was proved to have potent acaricidal activity.     

Acaricidal activities of bicyclic monoterpene ketones from Artemisia iwayomogi against Dermatophagoides spp.

The acaricidal properties of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one isolated from Artemisia iwayomogi and its structural analogues were evaluated against Dermatophagoides farinae and D. pteronyssinus, and their effects were compared with that of the commercial acaricide benzyl benzoate. Based on the 50 % lethal dose (LD₅₀) values against D. farinae, 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (0.82 μg/cm²) was 9.71 times more effective than benzyl benzoate (7.96 μg/cm²), followed by (1R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (1.03 μg/cm²), (1S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (1.58 μg/cm²), and (1R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one oxime (3.05 μg/cm²) in a filter paper bioassay. The acaricidal activities of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one and its structural analogues against D. pteronyssinus were similar to those against D. farinae. These results demonstrate that naturally occurring A. iwayomogi-isolated 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one and its structural analogues are suitable for the production of natural acaricides against house dust mites.     

Insecticidal activity of selected monoterpenoids and rosemary oil to Agriotes obscurus (Coleoptera: Elateridae)

Acute toxicities of three naturally occurring monoterpenoid essential oil constituents and the essential oil of rosemary were tested against late instars of Agriotes obscurus (L.) (Coleoptera: Elateridae). Both contact and volatile toxicities of thymol, citronellal, eugenol, and rosemary oil were determined. Also, phytotoxicity of these compounds was evaluated on corn germination and seedling development. Thymol had the greatest contact toxicity (LD50 = 196.0 microg/larva), whereas citronellal and eugenol were less toxic (LD50 = 404.9 and 516.5 microg/larva, respectively). Rosemary oil did not show any significant contact toxicity, even at 1,600 microg/larva. In terms of volatile toxicity, citronellal was the most toxic to wireworm larvae (LC50 = 6.3 microg/cm3) followed by rosemary oil (LC50 = 15.9 microg/cm3), thymol (LC50 = 17.1 microg/cm3), and eugenol (LC50 = 20.9 microg/cm3). Thymol, eugenol, and citronellal significantly inhibited corn seed germination and development, whereas rosemary oil had only minimal phytotoxic effects.     

The fauna, number and spatial distribution of mites (Acari) in house dust in Moscow

There is a wide and strong allergenic background in Moscow, which is determined by relatively high population density and regular frequency of the allergenic mites in various premises. 34 species have been identified, 5 of them are allergen producers. The mites of the family Pyroglyphidae are the main component of the house dust fauna. Dermatophagoides pteronyssinus and D. farinae distributed all over the world are predominate. A comparative evaluation of the fauna structure, numbers and frequency of the allergenic mites in the flat dust of the allergic patients and healthy people as well as premises is given. Possible importance of the premises in prevalence and circulation of the allergenic mites in the modern town is estimated for the first time.     

The comparative characteristics of different forms of allergens from mites of the genus Dermatophagoides]

The comparative study of allergenic preparations of Dermatophagoides mites [correction of ticks] from different manufacturers and the international standard preparations of such allergens was made. D. pteronyssinus and D. farinae allergens from the USSR and the Netherlands were studied. The samples under study were evaluated in a complex of in vivo and in vitro experiments. The preparations produced in the USSR and in the Netherlands exhibited pronounced specificity, but the allergens of both species from the Netherlands were more active. Some differences in the immunochemical characteristics of the preparations were noted.     

Isolation and characterisation of a 13.8-kDa bacteriolytic enzyme from house dust mite extracts: homology with prokaryotic proteins suggests that the enzyme could be bacterially derived

Bacteriolytic activity was detected in extracts of whole mite and spent growth medium (SGM) from the clinically important Dermatophagoides pteronyssinus and Dermatophagoides farinae mites and was most abundant in whole mite extract. Gram-positive organisms Micrococcus lysodeikticus, Bacillus megaterium and Listeria monocytogenes were preferentially lysed and the lytic activity was enhanced by thiols, destroyed by mite proteases, inhibited by HgCl2 and high concentrations of NaCl but was resistant to heat and acid treatment. Substrate SDS-PAGE analysis indicated the presence of several lytic enzymes, two of which were isolated from D. pteronyssinus spent growth medium extract by hydroxyapatite chromatography. The N-terminal amino acid sequence of one of them was then used in PCR-based cloning studies. The complete amino acid sequence of this protein was determined and cDNA found to encode a 130-amino acid residue mature protein with a 20-amino acid leader sequence. The deduced protein demonstrated sequence similarity with the C-terminal regions of a group of bacterial proteins belonging to the P60 superfamily. These data suggest that the enzyme is derived from bacteria within the mites rather than from mites per se.     

Allergenic mites (Acariformes, Pyroglyphidae) in house dust

Paper is the second part of the literature review on house dust mites (including 1985). It deals with the diagnosis of the dust mite allergy, the nature of the mite allergens, distribution and population density of the mites in various premises, seasonal population dynamics and population age structure of the dermatophagoid mites, life cycle and breeding of Dermatophagoides pteronyssinus and D. farinae on different food substrates. The methods of the house dust mite control are discussed. The original data on the house dust mite distribution in Moscow is shown. A comparative estimation of the results of mite antigens in the house dust discovering by the acarological and three immunological methods are given.     

Abundance of house dust mites in relation to climate in contrasting agricultural settlements in Israel

The correlation between climatic conditions and mite numbers in houses from rural areas was studied in 13 agricultural communities (kibbutzim and moshavim) in nine geo-climatic subregions of Israel. Mites were present in 97% of the dust samples. The average number of mites per gram of dust in the different localities ranged between 84 and 2053. The maximum number of mites (7440/g dust) was found in a carpet from a house in Geva Carmel in the northern coastal region. The most prevalent species of mites were Dermatophagoides pteronyssinus and Dermatophagoides farinae, which were found in 85.6% and 71.3% of the samples, respectively. The house dust mites D. pteronyssinus, D. farinae and Euroglyphus maynei constituted 94.8% of the mites. Most of the mites were isolated from the carpets and sofas (37.0% and 33.7%, respectively), and a smaller number from beds (29.3%). The smallest number of mites (< or = 250/g dust) were found at a minimum relative humidity (RH) of 30% and lower, with a maximum temperature of 32 degrees C and higher, i.e. in the Jordan valley and Negev mountains. A greater number of mites (250-500/g dust) were found at a minimum ambient RH of 35-40% and a maximum temperature of 32 degrees C and higher, i.e. the Hula valley. A large number of mites (500-1000/g dust) were found at a minimum RH of 35-40% with a maximum temperature of 30 degrees C and lower, i.e. in the Judean and Samarian range, as well as in upper Galilee. The largest number of mites (1000-2000/g dust) was found at a minimum RH of 45% and higher, with a maximum temperature ranging between 30 and 32 degrees C. These conditions occur in the coastal strip, the coastal plain and in the Judean and Samarian foothills. A monthly examination of two houses in Zova, a kibbutz in the Judean hills next to Jerusalem, and two houses from Palmachim, a kibbutz in the coastal region, revealed that the highest prevalence of mites was found in the months April-November and May-November, respectively. In Zova, the highest number of mites were found during the months of June and July while the highest concentrations of D. pteronyssinus-antigen (Der p I) were measured during the month of September. A positive correlation between mite numbers and the quantity of Der p I in house dust was found.     

Mites allergy in children from Tula region

Characteristics of allergy to mites in children living in Tula region have been revealed. It was shown that mites from Pyroglyphidae (Dermatophagoides pteronyssinus, Dermatophagoides farinae), Cheyletidae and Glycyphagidae (G. destructor, G. domesticus) families play important role in development of atopic allergy in children from this region. Efficacy of plant-origin acaricide "Milbiol" as part of prophylactic measures was evaluated. Its use in children with mild and intermediate asthma led to decrease of number of wheezing episodes, improvement of respiratory function, lessening of clinical signs of allergic rhinitis, decrease or discontinuation of usage of vasoconstrictive preparations.     

Effect of mite allergens on the electrophoretic mobility of guinea pig lymphocytes

The use of the method of electrophoretic mobility measurement has made it possible to demonstrate that Dermatophagoides pteronyssinus and Dermatophagoides farinae allergens are species-specific and possess common antigenic properties. The allergenic properties of D. pteronyssinus allergens are more pronounced than those of D. farinae allergens.     

Steroidal pyrazolines evaluated as aromatase and quinone reductase-2 inhibitors for chemoprevention of cancer

The aromatase and quinone reductase-2 inhibition of synthesized heterocyclic pyrazole derivatives fused with steroidal structure for chemoprevention of cancer is reported herein. All compounds were interestingly less toxic than the reference drug (Cyproterone(?)). The aromatase inhibitory activities of these compounds were much more potent than the lead compound resveratrol, which has an IC(50) of 80 μM. In addition, all the compounds displayed potent quinone reductase-2 inhibition. Initially the acute toxicity of the compounds was assayed via the determination of their LD(50). The aromatase and quinone reductase-2 inhibitors resulting from this study have potential value in the treatment and prevention of cancer.     

Detection of mite antigens in house dust in Moscow

The acarological+ study of dust samples from the homes of allergic patients and normal persons in Moscow mite antigens were detected, respectively, in 66.7% and 38.1% of homes. The indirect mast cell degranulation test and the brain gliacyte volume change test in white rats gave similar results. The occurrence of Dermatophagoides pteronyssinus was approximately twice as great of D. farinae, and the numerical prevalence of the former species over the latter one was 1.3-fold. Dermatophagoides mites occurred in the homes of allergic patients 1.8-2.3 times as frequently as in the homes of normal persons.     

Efficacy of various synthetic pyrethroid-impregnated encasement materials against house dust mite under laboratory conditions

The acaricidal activity of synthetic pyrethroid and benzyl benzoate against Dermatophagoides pteronyssinus was examined in the laboratory, using a specially designed test set up. On the basis of median lethal dose (LD₅₀) values, the compound found to be most toxic to D. pteronyssinus was benzyl benzoate (LD₅₀ = 50 mg/m²), followed by permethrin (LD₅₀ = 76.7 mg/m²), deltamethrin (LD₅₀ = 146.7 mg/m²), esbioallenthrin (LD₅₀ = 186.6 mg/m²) and lamdacyhalothrin (LD₅₀ = 756.6 mg/m²). Very low toxicity was observed with bifenthrin (LD₅₀ = 5157.8 mg/m²). A laboratory control trial was also carried out to compare the acaricidal activity (residual effect) of four pyrethroids impregnated on woven and non-woven encasement materials against house dust mites during a 4-month period. Of the pyrethroids used in this study, esbioallenthrin demonstrated the highest acaricidal activity, and of the pyrethroid impregnated materials, the non-woven encasement material was more effective than the woven encasement material.     

Use of isoelectric focusing in studying the composition of allergens from mites

The method of the isoelectric separation of allergens isolated from Dermatophagoides ticks with the use of isoelectrofocusing has been improved. 10-12 protein fractions with isoelectric points from 3.50 to 6.55 have been isolated. Allergens obtained from D. farinae and D. pteronyssinus grown on two different nutrient media have been found to contain common protein components. In D. pteronyssinus allergen the presence of a greater number of protein fractions has been noted in the region of pH 5.25-6.00 than in D. farinae allergen.     

House dust mite allergens in domestic homes in Cheonan, Korea

House dust mites produce inhalant allergens of importance to allergic patients. We measured the major group 1 allergens, Der p 1 and Der f 1, from the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farina, respectively in 100 randomly selected domestic homes from Cheonan, Korea. Dust samples were collected by vacuuming from the living room floor and 1 mattress in each home. Der p 1 and Der f 1 were measured by double monoclonal ELISA. Der p 1 levels were very low, with geometric mean levels for floors and mattresses being 0.11 microgram/g (range: 0.01-4.05) and 0.14 microgram/g (range: 0.01-30.0), respectively. Corresponding levels of Der f 1 were higher, 7.46 microgram/g (range: 0.01-262.9) and 10.2 microgram/g (range: 0.01-230.9) for floors and mattresses, respectively. D. farinae appears to be the dominant house dust mite in Cheonan.     

A diterpene quinone from the bark of Cryptomeria japonica

A diterpene, cryptoquinone, was isolated from the bark of Cryptomeria japonica, the structure, 7,11,14-trioxoabieta-8,12-diene, was established by spectral analyses and X-ray crystallography. This diterpene quinone showed moderate antifungal activities against Pyricularia orizae and Alternaria alternata, and cytotoxic activity against mouse lymphoid neoplasm (P388) cells with an IC(50) of 0.26 microg/ml.