A novel herbal formulation against dengue vector mosquitoes <Emphasis Type="Italic">Aedes aegypti</Emphasis> and <Emphasis Type="Italic">Aedes albopictus</Emphasis>

The objective of this study was to develop a herbal formulation to control dengue vector mosquitoes. PONNEEM, a novel herbal formulation prepared using the oils of neem (Azadirachta indica), karanj (Pongamia glabra) and their extracts, was tested for larvicidal, ovicidal and oviposition deterrent activities against Aedes aegypti and Aedes albopictus at 1, 0.5, 0.3 and 0.1 ppm concentrations. Cent percent larvicidal and ovicidal activities were observed at 0.1 ppm in the two mosquito species under laboratory and sunlight-exposed conditions up to 12 months from the date of manufacture. Oviposition deterrent activity of 69.97% and 71.05% was observed at 1 ppm concentration of PONNEEM against A. aegypti and A. albopictus, respectively. Reduction in enzyme levels for α-esterase was 0.089 ± 0.008 and 0.099 ± 0.140 μg napthol produced/min/mg larval protein; for β-esterase, it was 0.004 ± 0.009 and 0.001 ± 0.028 μg napthol produced/min/mg larval protein; for glutathione S-transferase, it was 10.4814 ± 0.23 and 11.4811 ± 0.21 μmol/min/mg larval protein and for total protein, it was 0.177 ± 0.010 and 0.008 ± 0.005 mg/individual larva in treated groups of A. aegypti and A. albopictus, respectively. The nontarget organisms such as Gambusia affinis and Diplonychus indicus were not affected. No mortality was observed in control. PONNEEM can be used effectively for the management of human vector mosquitoes.     

Molecular characterization of a<Emphasis Type="Italic"> Brugia malayi</Emphasis> transglutaminase

Prior studies have demonstrated that transglutaminase (TGase) from the human filarial parasite Brugia malayi is critical for the growth and development of the larval stages. In this report, we describe the cloning and partial characterization of a cDNA encoding the B. malayi TGase (BmTGase). Using RT-PCR and RACE-PCR, the cDNA was amplified from adult worm mRNA. BmTGase is 1,881 bp long and codes for a protein with a predicted molecular mass of 54 kDa. Amino acid sequence analysis of BmTGase revealed significant homology to the protein disulfide isomerase (PDI), particularly, to the PDI-related protein ERp60, a PDI isoform found in the lumen of endoplasmic reticulum. The activity of recombinant B. malayi TGase enzyme (rBmTG) was found to be calcium-dependent and could be inhibited by EDTA. ELISA studies showed that approximately 88% of 48 sera from healthy Indian patients living in a bancroftian filariasis endemic area were reactive with rBmTG. In contrast, only 33% of sera from patients with clinical filariasis were reactive to rBmTG. Non-endemic sera were uniformly non-reactive. Additional studies are needed to elucidate the role, if any, of B. malayi TGase in protective immunity to filariasis.     

Larvicidal activity of silver nanoparticles synthesized using <Emphasis Type="Italic">Plumeria rubra</Emphasis> plant latex against <Emphasis Type="Italic">Aedes aegypti</Emphasis> and <Emphasis Type="Italic">Anopheles stephensi</Emphasis>

In the present study activity of silver nanoparticles (AgNPs) synthesized using Plumeria rubra plant latex against second and fourth larval instar of Aedes aegypti and Anopheles stephensi was determined. Range of concentrations of synthesized AgNps (10, 5, 2.5, 1.25, 0.625, 0.3125 ppm) and aqueous crude latex (1,000, 500, 250, 125, 62.50, 31.25 ppm) were tested against larvae of A. aegypti and A. Stephensi. The synthesized AgNps from P. rubra latex were highly toxic than crude latex extract in both mosquito species. The LC₅₀ values for second and fourth larval instars after 24 h of crude latex exposure were 1.49, 1.82 ppm against A. aegypti and 1.10, 1.74 ppm against A. stephensi respectively. These figures were 181.67, 287.49 ppm against A. aegypti and 143.69, 170.58 ppm against A. stephensi respectively for crude latex extract. The mortality rates were positively correlated with the concentration of AgNPs. The characterization studies of synthesized AgNPs by UV–Vis spectrophotometry, transmission electron microscopy (TEM), Particle size analysis (PSA) and zeta potential confirmed the spherical shape and size (32–200 nm) of silver nanoparticles alongwith stability. Toxicity studies carried out against non-target fish species Poecilia reticulata, the most common organism in the habitats of A. aegypti and A. stephensi showed no toxicity at LC₅₀ and LC₉₀ doses of the AgNPs. This is the first report on mosquito larvicidal activity of latex synthesized nanoparticles.     

Effect of bioactive fractions of <Emphasis Type="Italic">Citrullus vulgaris</Emphasis> Schrad. leaf extract against <Emphasis Type="Italic">Anopheles stephensi</Emphasis> and <Emphasis Type="Italic">Aedes aegypti</Emphasis>

The benzene extract of Citrullus vulgaris was tested against Anopheles stephensi and Aedes aegypti for the larvicidal activity and ovicidal properties. The crude benzene extract was found to be more effective against A. stephensi than A. aegypti. The LC₅₀ values were 18.56 and 42.76 ppm respectively. The LC₅₀ values for silica gel fractions (bioactive fractions I, II, III and IV) were 11.32, 14.12, 14.53 and 16.02 ppm respectively. The mean per cent hatchability of the egg rafts were observed after 48 h post treatment. The crude extract of benzene exerted 100% mortality at 250 ppm against A. stephensi and at 300 ppm against A. aegypti. The silica gel fractions I and II afforded 100% mortality at 100 ppm and III and IV exerted the hatchability rate of 4.9 and 5.3% at the same concentration against A. stephensi.     

Effect of <Emphasis Type="Italic">Myracrodruon urundeuva</Emphasis> leaf lectin on survival and digestive enzymes of <Emphasis Type="Italic">Aedes aegypti</Emphasis> larvae

Aedes aegypti transmits the viruses that cause yellow and dengue fevers. Vector control is essential, since a vaccine for dengue has not as yet been made available. This work reports on the larvicidal activity of Myracrodruon urundeuva leaf lectin (MuLL) against A. aegypti fourth-stage larvae (L₄). Also, the resistance of MuLL to digestion by L₄ gut proteases and the effects of MuLL on protease, trypsin-like and α-amylase activities from L₄ gut were evaluated to determine if lectin remains active in A. aegypti gut and if insect enzyme activities can be modulated by MuLL. MuLL promoted mortality of L₄ with LC₅₀ of 0.202 mg/ml. Haemagglutinating activity of MuLL was detected even after incubation for 96 h with L₄ gut preparation containing protease activity. MuLL affected the activity of gut enzymes, inhibiting protease and trypsin activities and stimulating α-amylase activity. The results suggest that MuLL may become a new biodegradable larvicidal agent for dengue control. Larvicidal activity of MuLL may be linked to its resistance to proteolysis by larval enzymes and interference in the activity of digestive larval enzymes.     

First report on susceptibility of wild <Emphasis Type="Italic">Aedes aegypti</Emphasis> (Diptera: Culicidae) using <Emphasis Type="Italic">Carapa guianensis</Emphasis> (Meliaceae) and <Emphasis Type="Italic">Copaifera</Emphasis> sp. (Leguminosae)

Oils of Carapa guianensis and Copaifera spp. are well known in the Amazonian region as natural insect repellent, and studies have reported their efficiency as larvicide against some laboratory mosquito species. However, in wild populations of mosquitoes, these oils have not yet been evaluated. Thus, the objective of this study was to investigate their efficiency as larvicide in wild populations of Aedes aegypti with a history of exposure to organophosphate. The susceptibility of larvae was determined under three different temperatures, 15°C, 20°C, and 30°C. For each test, 1,000 larvae were used (late third instar and early fourth instar—four replicates of 25 larvae per concentration). Statistical tests were used to identify significant differences. The results demonstrated that as the laboratory A. aegypti, the wild populations of A. aegypti were also susceptible to C. guianensis and Copaifera sp. oils. The lethal concentrations for Copaifera sp. ranged from LC₅₀ 47 to LC₉₀ 91 (milligrams per liter), and for C. guianensis, they were LC₅₀ 136 to LC₉₀ 551 (milligrams per liter). In relation to different temperature, the effectiveness of the oils on larvae mortality was directly related to the increase of temperature, and better results were observed for temperature at 25°C. The results presented here indicate the potential larvicidal activity of C. guianensis and species of Copaifera, in populations of A. aegypti from the wild. Therefore, the results presented here are very important since such populations are primarily responsible for transmitting the dengue virus in the environment.     

Adulticidal and repellent properties of indigenous plant extracts against <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis> and <Emphasis Type="Italic">Aedes aegypti</Emphasis> (Diptera: Culicidae)

Several diseases are associated to the mosquito–human interaction. Mosquitoes are the carriers of severe and well-known illnesses such as malaria, arboviral encephalitis, dengue fever, chikunguniya fever, West Nile virus, and yellow fever. These diseases produce significant morbidity and mortality in humans and livestock around the world. The adulticidal and repellent activities of crude hexane, ethyl acetate, benzene, chloroform, and methanol extracts of leaf of Eclipta alba and Andrographis paniculata were assayed for their toxicity against two important vector mosquitoes, viz., Culex quinquefasciatus and Aedes aegypti (Diptera: Culicidae). The adult mortality was observed after 24 h of exposure. All extracts showed moderate adulticide effects; however, the highest adult mortality was found in methanol extract of A. paniculata against the adults of C. quinquefasciatus and A. aegypti with the LC₅₀ and LC₉₀ values were 149.81, 172.37 ppm and 288.12, 321.01 ppm, respectively. The results of the repellent activity of hexane, ethyl acetate, benzene, chloroform, and methanol extract of E. alba and A. paniculata plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm² were applied on skin of forearm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf solvent plant extracts have the potential to be used as an ideal ecofriendly approach for the control of mosquitoes. This is the first report on the mosquito adulticidal and repellent activities of the reported E. alba and A. paniculata plants.     

Electroantennogram,flight orientation,and oviposition responses of <Emphasis Type="Italic">Aedes aegypti</Emphasis> to the oviposition pheromone <Emphasis Type="Italic">n</Emphasis>-heneicosane

Oviposition pheromones specifically influence the females of many insects to lay eggs in the sites resulting in more egg deposition. A previous report describes the principal role of n-heneicosane (C₂₁) identified and characterized from the larval cuticle of Aedes aegypti (L.) in attracting the gravid mosquitoes to oviposit in treated substrates among other chemical components. However, the means by which this compound is perceived by the females for oviposition has not been reported. In this study, we have recorded the peripheral olfactory responses from the antenna of Ae. aegypti from 10⁻⁷ g to 10⁻³ g doses of n-heneicosane. The EAG response of female mosquitoes increased in a dose-dependent manner with increasing stimulus strength. In the orientation assay using Y-maze olfactometer, female mosquitoes were attracted to the odor plume of 10⁻⁶ g and 10⁻⁵ g dose, while the higher dose of 10⁻³ g plume enforced repellency to gravid mosquitoes. The response to oviposition substrates by gravid Ae. aegypti females differed across the range of concentrations of n-heneicosane under multiple choice conditions, larger number of eggs were deposited in 10 ppm (10 mg/l) solutions compared to lower and higher concentrations indicating 10 ppm was most attractive. Application of n-heneicosane at 10 ppm in breeding habitats will be a useful method to attract the gravid mosquitoes using ovitraps for surveillance and monitoring. The possible use of this compound in monitoring of mosquito population in endemic areas in relevance to integrated vector management strategies is discussed in detail.     

Translationally controlled tumor protein of <Emphasis Type="Italic">Brugia malayi</Emphasis> functions as an antioxidant protein

Translationally controlled tumor protein (TCTP) is one of the most abundantly expressed proteins in the filarial parasites as well as in the other organisms. Several functions have been suggested for TCTP family of proteins ranging from calcium binding to histamine release function. However, its physiological function is still a mystery. Previous studies showed that the expression of TCTP is increased several-fold during oxidative stress. In the present work, we report the putative antioxidant function of Brugia malayi TCTP (BmTCTP). When tested in vitro, rBmTCTP could be reduced by a variety of reducing agents including thioredoxin. Such reduced form of rBmTCTP was able to protect DNA from oxidative damage, suggesting that BmTCTP may have an antioxidant function in the parasite. Sequence analysis of filarial TCTPs revealed that there are three cysteine amino acids located in the central portion of the protein. Subsequent targeted residue modification studies showed that these cysteine residues in rBmTCTP are critical for its antioxidant function. To determine the significance of this finding, rBmTCTP was overexpressed in vivo in Escherichia coli and subjected to oxidative stress. These studies showed that rBmTCTP significantly protected cells form oxidative damage. Taken together, these findings suggest that BmTCTP might be functioning as a non-classical antioxidant protein in the filarial parasites.     

The <Emphasis Type="Italic">Wolbachia</Emphasis> endosymbiont of <Emphasis Type="Italic">Brugia malayi</Emphasis> has an active phosphoglycerate mutase: a candidate target for anti-filarial therapies

Phosphoglycerate mutases (PGM) interconvert 2- and 3-phosphoglycerate in the glycolytic and gluconeogenic pathways. A putative cofactor-independent phosphoglycerate mutase gene (iPGM) was identified in the genome sequence of the Wolbachia endosymbiont from the filarial nematode, Brugia malayi (wBm). Since iPGM has no sequence or structural similarity to the cofactor-dependent phosphoglycerate mutase (dPGM) found in mammals, it may represent an attractive Wolbachia drug target. In the present study, wBm–iPGM cloned and expressed in Escherichia coli was mostly insoluble and inactive. However, the protein was successfully produced in the yeast Kluyveromyces lactis and the purified recombinant wBm–iPGM showed typical PGM activity. Our results provide a foundation for further development of wBm–iPGM as a promising new drug target for novel anti-filarial therapies that selectively target the endosymbiont.     

Antifilarial activity of<Emphasis Type="Italic"> Zoanthus</Emphasis> species (Phylum Coelenterata,Class Anthzoa) against human lymphatic filaria,<Emphasis Type="Italic"> Brugia malayi</Emphasis>

The chloroform methanol (1:1) extract of an unidentified green zoanthus (Phylum Coelenterata, Class Anthozoa) showed promising in vitro adulticidal activity with a lethal concentration of 125 g/ml on Brugia malayi. This extract brought about a 52.2% reduction in circulating microfilariae of B. malayi when administered to infected Mastomys coucha at 250 mg/kg, orally for 5 consecutive days. Further fractionation of the extract led to the recovery of four fractions, which were evaluated simultaneously in both in vitro and in vivo systems against B. malayi. The chloroform fraction at 250 mg/kg orally for 5 days exhibited the highest macrofilaricidal action (42.5%), closely followed by the insoluble n-butanol fraction(34.3%), the soluble hexane fraction (32.4%), and the soluble n-butanol fraction (20.4%). In addition, the hexane soluble fraction caused 44.3% sterilization of the surviving female parasites. Two compounds isolated were found devoid of antifilarial activity.     

Larvicidal activity of micronized aqueous suspension of calcium hydroxide against <Emphasis Type="Italic">Aedes aegypti</Emphasis> and <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis> (Diptera: Culicidae)

In the search of alternatives for the control of mosquitoes of medical importance, we evaluated the larvicidal activity of micronized suspensions of calcium hydroxide [Ca(OH)₂] against Aedes aegypti and Culex quinquefasciatus. Tests conducted under laboratory conditions determined a LC50 = 0.027% (LC90 = 0.096%) for A. aegypti and a LC50 = 0.092% (LC90 = 0.2%) for C. quinquefasciatus, at 24 h post-treatment. Considering that the LC50 for the less susceptible species killed 100% of larvae for both species at 48 h post-treatment, we decided to use the diagnostic concentration of 0.1% which eliminated 100% of larvae at 48 h under a simulated field trial. There was a residual effect for up to 84 and 70 days for A. aegypti and C. quinquefasciatus, respectively. Evaluation of Ca(OH)₂ on breeding sites showed a larvicidal activity of 100% for up to 56 days. When the micronized Ca(OH)₂ was incorporated at concentrations from 0.02% (w/v), a superficial film was formed which killed 100% of the larvae of both species after 24 h of contact, and the activity remains until the film broke apart due to stirring. The fact that Ca(OH)₂ is cheap and the people in rural areas of Mexico and other countries know the handling procedures for this compound led us to consider that 0.1% suspensions of Ca(OH)₂ could be used for mosquito control in deposits of water placed in human premises both in urban and rural areas.     

Cercarial shedding from <Emphasis Type="Italic">Galba</Emphasis><Emphasis Type="Italic">truncatula</Emphasis> infected with <Emphasis Type="Italic">Fasciola</Emphasis><Emphasis Type="Italic">gigantica</Emphasis> of distinct geographic origins

Galba truncatula snails were experimentally infected with either of two different isolates of Fasciola gigantica, originating from Egypt or China, to determine the influence of these isolates on the characteristics of snail infections. The survival rates of G. truncatula on day 30 post-exposure were 90.0% and 60.2% in the Egyptian and Chinese groups, respectively. The frequency of cercaria-shedding snails within the Egyptian group was 79.8%, whereas in the Chinese group it was 22.4%. The parasite origin had a significant effect on the durations of the prepatent and patent periods. The mean number of cercariae shed from the Egyptian group was significantly greater than that shed from the Chinese group (a mean of 275.5 per cercaria-shedding snail compared with 29.0). These results could be explained by the fact that G. truncatula might be a natural intermediate host for F. gigantica in Egypt, and the greater adaptability of the Egyptian miracidia of F. gigantica to unusual snail hosts. These results demonstrate the influence of the geographic origin of the parasite on the success of trematodes infecting snails.     

Efficacy of fungus mediated silver and gold nanoparticles against <Emphasis Type="Italic">Aedes aegypti</Emphasis> larvae

Chrysosporium tropicum is a pathogenic fungus. It is known to be an effective mosquito control agent. In the present study, we have synthesized the silver and gold nanoparticles using C. tropicum. These nanoparticles have been characterized through Microscan reader, X-ray diffractometer, transmission electron microscopy, and further confirmed by scanning electron microscopy. The characterization study confirmed the spherical shape and size (2–15 and 20–50 nm) of gold and silver nanoparticles. These silver and gold nanoparticles have been tested as a larvicide against the Aedes aegypti larvae. The larvicidal efficacy was noted when performed against all instars of A. aegypti at six different log concentrations, and significant results could be observed. The gold nanoparticles used as an efficacy enhancer have shown mortality at three times higher concentration than the silver nanoparticles. The larval mortality was observed after different time of exposures. The mortality values were obtained using the probit analysis. The larvae of A. aegypti were found to be highly susceptible for the silver nanoparticles. The second instar larvae have shown 100% mortality against the silver nanoparticles after 1 h, whereas the first, third, and fourth instars have shown efficacy (LC₅₀ = 3.47, 4, and 2; LC₉₀ = 12.30, 8.91, and 4; LC₉₉ = 13.18, 13.18, and 7.58, respectively) after 1 h. The results could suggest that the use of fungus C. tropicum, silver, and gold nanoparticles is a rapid, environmentally safer, and greener approach for mosquito control. This could lead us to a new possibility in vector control strategy.     

Cysteine proteinases from promastigotes of <Emphasis Type="Italic">Leishmania</Emphasis> (<Emphasis Type="Italic">Viannia</Emphasis>) <Emphasis Type="Italic">braziliensis</Emphasis>

Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of 63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection.     

Redescription of <Emphasis Type="Italic">Lemuricola</Emphasis> (<Emphasis Type="Italic">Madoxyuris</Emphasis>) <Emphasis Type="Italic">bauchoti</Emphasis> (Nematoda,Oxyuridae) from <Emphasis Type="Italic">Lemur catta</Emphasis> in Madagascar

Lemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini hosts will only be proven when additional records fill in the gaps in their distribution.     

Bioactivity of flavonoid compounds from <Emphasis Type="Italic">Poncirus trifoliata</Emphasis> L. (Family: Rutaceae) against the dengue vector, <Emphasis Type="Italic">Aedes aegypti</Emphasis> L. (Diptera: Culicidae)

The bioactivity of four flavonoid compounds, namely poncirin, rhoifolin, naringin and marmesin, from Poncirus trifoliata was studied against the Aedes aegypti. Larvicidal assays were conducted to evaluate the 24 h LC(50) and LC(90) values of the flavonoid compounds. The lethal concentration (LC(50) and LC(90)) values ranged from 0.082 to 0.122 mg/l and 0.152 to 0.223 mg/l, respectively. The result of ovicidal test suggests that the ovicidal activity of the flavonoid compounds was influenced by the concentration of flavonoid compounds and age of the eggs. The result of oviposition test showed that the four flavonoid compounds exhibited oviposition-deterrent activity against gravid female mosquitoes. Oviposition decreased with an increase in concentration of flavonoid compounds. A laboratory test was carried out to evaluate protection period and percentage of repellency of four compounds diluted in ethanol (10 mg/l). The compound rhoifolin provided maximum 365.0 +/- 12.0 min protection and also 100.0% +/- 0.0 repellency against mosquito bite followed by poncirin, marmesin and naringin. None of the 25 volunteers of either sex exposed to 10% (w/v) flavonoid compounds (4-h patch test) showed a positive skin irritant reaction. All of the tested compounds proved to have various activities against different life stages of A. aegypti. Therefore, flavonoid compounds from P. trifoliata can be a potential candidate for use in the development of commercial mosquitocidal products that may be an alternative to conventional synthetic chemicals, particularly in integrated vector control applications.     

<Emphasis Type="Italic">Trypanosoma</Emphasis> (<Emphasis Type="Italic">Herpetosoma</Emphasis>) <Emphasis Type="Italic">kuseli</Emphasis> sp. n. (Protozoa: Kinetoplastida) in Siberian flying squirrels (<Emphasis Type="Italic">Pteromys volans</Emphasis>)

All trypanosome species classified in the subgenus Herpetosoma in sciurid hosts have been recorded from ground and tree squirrels to date, but not from any flying squirrels. We describe in this paper a novel trypanosome species, Trypanosoma (Herpetosoma) kuseli sp. n., from Siberian flying squirrels (Pteromys volans) imported from China, and compare it with T. (H.) otospermophili in Richardson's ground squirrels (Spermophilus richardsonii) and Columbian ground squirrels (Spermophilus columbianus) from the USA. Due to a short free flagellum, the new species appeared stumpy compared with T. otospermophili (length of free flagellum 7.0 +/- 0.8 microm, total length 32.1 +/- 0.8 microm, n = 13 and length of free flagellum 15.5 +/- 1.6 microm, total length 35.9 +/- 1.0 microm, n = 13, respectively). Another conspicuous morphological feature of the new species was an anteriorly positioned kinetoplast, found approximately at the midpoint between the nucleus and the posterior end. These characters have not been recorded from any squirrel Herpetosoma trypanosome species. Comparison of the nucleotide sequences of the small and large subunit rRNA genes indicated that T. kuseli sp. n. was more homologous to T. otospermophili than murid Herpetosoma species, such as T. grosi, T. lewisi, T. musculi, T. microti and T. evotomys.     

Antiviral biflavonoids from <Emphasis Type="Italic">Radix Wikstroemiae</Emphasis> (<Emphasis Type="Italic">Liaogewanggen</Emphasis>)

Background  

Radix Wikstroemiae is a common Chinese herbal medicine. The ethyl acetate fraction of the ethanolic extract of W. indica possesses potent in vitro antiviral activity against respiratory syncytial virus (RSV). This study aims to identify the antiviral components of the active fraction.