A nematicidal tannin from Punica granatum L. rind and its physiological effect on pine wood nematode (Bursaphelenchus xylophilus).

The ethanol extract of Punica granatum L. rind was tested to show significant nematicidal activity against pine wood nematode. Three nematicidal compounds were obtained from the ethanol extract by bioassay-guided fractionation and identified as punicalagin 1, punicalin 2, and corilagin 3 by mass and nuclear magnetic resonance spectral data analysis. Punicalagin 1 was most active against PWN among the purified compounds with the LC50 value of 307.08µM in 72h. According to the enzyme assays in vitro, punicalagin 1 could inhibit the activity of acetylcholinesterase, amylase and cellulase from PWN with IC50 value of 0.60mM, 0.96mM and 1.24mM, respectively. The morphological structures of PWNs treated by punicalagin 1 were greatly changed. These physiological effects of punicalagin 1 on PWN may helpful to elucidate its nematicidal mechanism.

Copper(II) oxide nanoparticles augment antifilarial activity of Albendazole: In vitro synergistic apoptotic impact against filarial parasite Setaria cervi.

Mass treatment of lymphatic filariasis with Albendazole (ABZ), a therapeutic benzimidazole, is fraught with serious limitations such as possible drug resistance and poor macrofilaricidal activity. Therefore, we need to develop new ABZ-based formulations to improve its antifilarial effectiveness. CuO nanoparticles were used as an adjuvant with ABZ to form ABZ-CuO nanocomposite, which was characterized by UV-vis spectroscopy, FT-IR, AFM and SEM. Antifilarial activity of nanocomposite was evaluated using relative motility assay and dye exclusion test in dark and under UV light. ROS generation, antioxidant levels, lipid peroxidation and DNA fragmentation in nanocomposite treated parasites were estimated. Biophysical techniques were employed to ascertain the mode of binding of nanocomposite to parasitic DNA. Nanocomposite increases parasite mortality as compared to ABZ in dark, and its antifilarial effect was increased further under UV light. Elevated ROS production and decline of parasitic-GST and GSH levels were observed in nanocomposite treated worms in dark, and these effects were pronounced further under UV light. Nanocomposite leads to higher DNA fragmentation as compared to ABZ alone. Further, we found that nanocomposite binds parasitic DNA in an intercalative manner where it generates ROS to induce DNA damage. Thus, oxidative stress production due to ROS generation and consequent DNA fragmentation leads to apoptosis in worms. This is the first report supporting CuO nanoparticles as a potential adjuvant with ABZ against filariasis along with enhanced antifilarial activity of nanocomposite under UV light. These findings, thus, indicate that development of ABZ-loaded nanoparticle compounds may serve as promising leads for filariasis treatment.

Effects of chloroform extract of Dryopteris crassirhizoma on the ultramicroscopic structures of Meloidogyne incognita.

In our early experiments, the chloroform extract of D. crassirhizoma was demonstrated to contain the highest concentrations of total phloroglucinols among several extract fractions and possessed the most effective nematicidal activity. This study aimed to ascertain the ultrastructural changes in M. incognita after treatment with a D. crassirhizoma chloroform extract at 1 mg·mL⁻¹ for 24 h. It was found that the extract exhibited significant destructive effects on the worm's ultrastructure and caused distinctive damage to body surfaces and internal structures. These results will contribute to a deeper understanding of the nematicidal mechanism of D. crassirhizoma, as well as in the design of efficient bionematicides.

Nematotoxicity of drupacine and a Cephalotaxus alkaloid preparation against the plant-parasitic nematodes Meloidogyne incognita and Bursaphelenchus xylophilus.

BACKGROUND: Species of Cephalotaxus (the plum yews) produce nematotoxic compounds of unknown identity. Consequently, bioassay-guided fractionation was employed to identify the compound(s) in Cephalotaxus fortunei twigs and leaves with activity against plant-parasitic nematodes. RESULTS: A crude alkaloid extract, particularly drupacine, was responsible for much of the nematotoxicity. The ED50 of drupacine for Bursaphelenchus xylophilus was 27.1 µg mL⁻¹, and for Meloidogyne incognita it was 76.3 µg mL⁻¹. Immersion of M. incognita eggs in 1.0 mg mL⁻¹ crude alkaloid extract (the highest tested concentration) reduced hatch by 36%; immersion of second-stage juveniles (J2) resulted in 72-98% immobility. Crude alkaloid extract and drupacine suppressed protease activity in extracts of the microbivorous nematode Panagrellus redivivus by 50% and 80%, respectively. Application of 0.02-0.5 mg mL⁻¹ crude alkaloid extract to soil with M. incognita inoculum did not significantly reduce pepper plant shoot length or weight, compared with nematode-inoculated, water-treated controls, but the number of eggs and J2 per root system respectively decreased by 69% and 73% at 0.5 mg mL⁻¹. CONCLUSION: Drupacine and a crude alkaloid extract suppress nematode hatch, activity of mixed life stages, and population numbers on plant roots. This is the first demonstration of nematotoxicity of crude Cephalotaxus alkaloids and drupacine.

Anthelmintic potential of three plants used in Nigerian ethnoveterinary medicine.

CONTEXT: The leaves of Irvingia gabonensis Baill. Ex Lanen (Irvingiaceae), Ficus exasperata Vahl (Moraceae), and Vernonia amygdalina Delile (Asteraceae) are folklorically used in treating worm infestation in Eastern Nigeria. The anthelmintic potential of the ethanol extracts of the leaves of I. gabonensis, F. exasperata, and V. amygdalina was investigated. MATERIALS: Acute toxicity tests were done in mice using 10, 100, and 1000 mg/kg/bw of extracts. In vitro larval assays of Heligmosomoides bakeri larvae at various extract concentrations (125, 250, and 500 mg/kg) were done. Mice experimentally infected with H. bakeri were treated with F. exasperata extract (200, 400, 800 mg/kg). RESULTS: At concentrations of 500, 250, and 125 mg/ml F. exasperata caused 100% larval mortality. V. amygdalina extract caused 71.43, 57.14, and 57.14% larval deaths while I. gabonensis extract caused 71.43, 57.14, and 42.9% larval deaths at the same concentrations. There was no significant difference in the fecal egg output, packed cell volumes and body weights of the F. exasperata treated mice when compared with the infected untreated group. DISCUSSION AND CONCLUSION: Leaf extracts of F. exasperata, V. amygdalina, and I. gabonensis exhibited varying degrees of larvicidal activities on the infective stage larvae of H. bakeri in vitro whereas F. exasperata showed no activity on the parasites in vivo.

Stereoisomeric separation and toxicity of the nematicide fosthiazate.

Considerable attention has been paid to the enantiomeric resolution and toxicity of some chiral organophosphorous pesticides (OPs) with one asymmetric center, but research concerning chiral OPs with two asymmetric centers is still limited. In the present study, the stereoisomeric separation and toxicity of fosthiazate, a chiral OP with two asymmetric centers on phosphorus and carbon atoms, was investigated. All four stereoisomers of fosthiazate were separated successfully with a Chiralpak(R) AD [amylase tris(3,5-dimethyl-phenyl carbamate)] column on high-performance liquid chromatography. The resolved isomers and the pairs of enantiomers were further distinguished using a circular dichroism detector and an optical rotation detector, designating the first (pk1) and third (pk3) eluted peaks as one pair of enantiomers and the second (pk2) and fourth (pk4) peaks as the other pair. The developed method was used to prepare microquantities of individual stereoisomers that were used for in vitro and in vivo bioassays. The inhibition potencies of the stereoisomers against acetylcholinesterase of Electrophorus electricus were slightly stereoselective, with a maximum difference of 1.4-fold among the isomers. A 3.1-fold difference, however, was observed in the acute toxicity of isomers to Daphnia magna. The 48-h toxicity of isomers to D. magna followed the order pk1 > pk2 > pk4 > racemate approximately pk3. The stereoselective toxicity to D. magna found in fosthiazate suggests that the environmental safety of fosthiazate should be evaluated on the basis of its individual isomers.

Screening and isolation of a nematicidal sesquiterpene from Magnolia grandiflora L.

The ethanolic extracts from 30 plant species were tested for their nematicidal activity against nematodes Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle and Panagrellus redivivus (L.) Goodey. The leaf extract of Magnolia grandiflora L. exhibited the strongest nematicidal activity against both nematodes, causing 73 and 100% mortality respectively within 48 h at 5 mg mL(-1). A new nematicidal sesquiterpene was obtained from the leaves of M. grandiflora. The compound was determined to be 4,5-epoxy-1(10)E,11(13)-germacradien-12,6-olide, based on spectroscopic methods including 2D NMR techniques. The median lethal concentrations (LC50) of the compound against B. xylophilus and P. redivivus were 71 and 46 mg L(-1) respectively at 48 h. This is the first report of Magnoliaceae species with nematicidal activity.

Toxicity of binary mixtures of cadmium-copper and carbendazim-copper to the nematode Caenorhabditis elegans.

For ecological risk assessment, the additive model may be used to empirically predict toxic mixture effects. Detailed toxicity tests were performed to determine whether effects of mixtures of copper-cadmium and copper-carbendazim on Caenorhabditis elegans were similar to the effects of the individual compounds. Effects on the course of reproduction, the length of the juvenile period, the length of the reproductive period, and body length were analyzed. Dose-response data were compared to the additive model and tested for four deviation patterns from additivity: No deviation, synergistic/antagonistic deviation, dose ratio-dependent deviation, dose level-dependent deviation. During the exposure, the cadmium-copper effect on reproduction changed from a synergistic, to a dose ratio-dependent deviation from additivity. More cadmium in the mixture decreased the toxicity and more copper increased the toxicity. The effect of copper-carbendazim on reproduction was synergistic at low dose levels and antagonistic at high dose levels and independent of time. Mixture effects on the juvenile and reproductive period were similar to single component effects. It was concluded that the observed time-dependence of toxic interactions was small and that interactions on the timing of reproduction were not found. The additive model underestimated mixture effects on reproduction and body length.

Ascaridole-less infusions of Chenopodium ambrosioides contain a nematocide(s) that is(are) not toxic to mammalian smooth muscle.

Infusions of Chenopodium ambrosioides (L.) have been used for centuries in the Americas as a popular remedy against intestinal worm infections. The essential oil of Chenopodium ambrosioides contains high levels of ascaridole, which is a potent anthelmintic, but which has also been responsible for human fatalities, leading to its disuse. Almost 90% of the nematocidal activity of Chenopodium ambrosioides infusions was due to a hydrophilic component different from ascaridole. Synthetic ascaridole and the ascaridole from infusions, extracted into hexane, caused a reduction of carbachol-induced contractions in rat gastrointestinal smooth muscle at concentrations required to kill Caenorhabditis elegans (L.). The herbal infusion and the ascaridole-free hexane-extracted aqueous residue of the above infusion, at nematocidal concentrations, had no detectable effect on smooth muscle contraction in the above system. It would appear that the traditional form of usage of Chenopodium ambrosioides infusions as a vermifuge is safer than the use of the herb's essential oil.

[A trial of the preparation Cheblin-SK-1 in models of nematodiases]. / Ispytanie preparata Cheblin-SK-1 na modeliakh nematodozov.

A kerosene milky-stage walnut (Juglans spp.) extract, a folk medication, has come into wide use in the past 30 years. The drug CK-I was prepared on a scientific basis. Its acute toxicity and toxicological profile were studied on albino mice and rats, chickens, chicken embryos, piglets. The maximum non-lethal dose of CK-I was 19 g/kg for albino mice and 21 g/kg for albino rats. The drug can be classified as i.v. hazard class. The anthelmintic effects of CK-I were examined in mice with cyphaciasis and in chickens with ascariasis and heterakiasis. In murine cyphaciasis, CK-I given in a dose of 75 mg/kg to albino mice provided 100% efficiency. Its doses of 800 and 1000 mg/kg were required to achieve this effect in chick ascariasis and heterakiasis, respectively.

Antibacterial, anthelmintic and anti-amoebic activity in South African medicinal plants.

Hexane, ethanol and water extracts of plants used by South African traditional healers for treating stomach ailments were screened for antibacterial, anthelmintic and anti-amoebic activities. To evaluate antibacterial activity, the disc-diffusion assay was used against several Gram-positive and Gram-negative species. Minimal inhibitory concentration values were determined with a microdilution assay. Ethanolic extracts showed the greatest activity, and Gram-positive bacteria were the most susceptible microorganisms. The free-living nematode Caenorhabditis elegans was used in two different assays to evaluate anthelmintic activity. A microdilution technique was employed to investigate anti-amoebic activity against the enteropathogenic Entamoeba histolytica. These assays were suitable for the screening of a large number of extracts at one time. Several plants exhibited significant activity against these test organisms.

[The search for new antiparasitic agents. 18. The synthesis and antitrichinelliasis activity of 1-[(2-acylamino)phenyl]-3,4-dihydroisoquinolines]. / Izyskanie novykh protivoparazitarnykh sredstv. 18. Sintez i protivotrikhinelleznaia aktivnost' nekotorykh 1-[(2-atsilamino)fenil]-3,4-digidroizokhinolinov.

New 1-[(2-acylamino)phenyl]-3, 4-dihydroisoquinolines were synthesized and tested for their acute toxicity and antitrichinosis activity. The above compounds were found to show their low toxicity and two compounds (G-1615 and G-1616) displayed a high antitrichinosis effect.

[The synthesis and study of the acute toxicity and anthelmintic activity of new 2-methylthiobenzimidazoles]. / Sintez, izuchenie ostroi toksichnosti i protivogel'mintnoi aktivnosti novykh 2-metiltiobenzimidazolov.

Several derivatives of 2-methylthiobenzimidazoles were synthesized and assayed for anthelmintic activity. Following these studies, 2-methylthio-5-(1-chloronaphthyloxy-2)-6-chlorobenzimidazole (G-1557) has been selected as a tichinellacide for detailed investigations.

[The technology for manufacturing antiparasitic preparations. 3. The development of a technology for producing the anthelmintic embovin (pyrantel embonate) in finely dispersed form and the evaluation of its anthelmintic properties]. / Tekhnologiia proizvodstva protivoparazitarnykh preparatov. 3. Razrabotka tekhnologii polucheniia antigel'mintika émbovina (pirantelia émbonata) v melkodispersnoi forme i otsenka ego protivogel'mintnykh svoistv.

Manufacturing process for anthelmintic embovin in a micronized form have been developed. Embovin in the micronized form exhibited the highest activity.

Novel nematocidal agents from Curcuma comosa.

Curcuma comosa is a member of the economically important plant family, Zingiberaceae. A methanolic extract of C. comosa was shown to be nematocidal when tested against the free-living nematode Caenorhabditis elegans. Five diphenylheptanoids [1-5], one new and four known, have been isolated and shown to be responsible for the activity. This is the first report of three of these compounds [1, 2, 4] being isolated from a natural source.

[The synthesis and study of the acute toxicity and anthelmintic activity of salicylanilides containing a quinoline residue]. / Sintez, izuchenie ostroi toksichnosti i protivogel'mintnoi aktivnosti salitsilanilinov, soderzhashchikh ostatok khinolina.

Salicylanilides containing quinoline moiety were synthesized and examined for acute toxicity and antinematodal activity. All the compounds were shown to possess a low toxicity. In the trials on a nematodal model (Aspiculuris tetraptera, white mice), 2 compounds--G-1570 and G-1575--were shown to be highly effective.

[The efficacy of a new Russian preparation metiazol in experimental aspiculariasis in mice]. / Izuchenie éffektivnosti novogo otechestvennogo preparata metiazola pri éksperimental'nom aspikuluroze u myshei.

The efficacy of metiasole, a new Russian analog of albendasole, reproduced at the E. I. Martsinovskii Institute of Medical Parasitology and Tropical Medicine, was studied in mice with Aspiculuris tetraptera invasion. Metiasole efficacy and acute toxicity were comparable to those of embovin and superior to those of medamin. Relationship between the drug efficacy and its doses and number of injections was analyzed.

Effects of 1,3-dichloropropene on the kidney of Fisher 344 rats after pretreatment with diethyl maleate, buthionine sulfoximine, and aminooxyacetic acid.

Acute nephrotoxicity of cis/trans-1,3-dichloropropene (DCP) was assessed in male Fisher 344 rats. Pretreatment of rats with corn oil, aminooxyacetic acid (AOA), buthionine sulfoximine (BSO), or diethyl maleate (DEM) was given intraperitoneally 1 h or 4 h prior to injection of DCP. Doses of DCP were 0, 25, 50, and 75 mg/kg intraperitoneally (4-5 animals per dose/pretreatment group). Urine was collected for 24 h. Excretion of creatinine, phosphorus, protein, N-acetylglucosaminidase (NAG), and the major metabolite of DCP, N-acetyl-S-(cis-3-chloroprop-2-enyl)-cysteine (3CNAC), was measured. Excretion of the metabolite, 3CNAC, increased in a dose-related manner from 0 to 50 mg/kg of DCP, but further increases were not seen at the 75 mg/kg dose. The pretreatments produced no alterations in the amounts of metabolite excreted when compared to corn oil controls. Zero-order metabolism or impaired metabolism is suggested to be occurring at high doses of DCP. The AOA pretreatment group showed no increase in the excretion of NAG, whereas other pretreatments (corn oil, BSO, DEM) showed elevations of NAG excretion at the highest DCP doses. AOA inhibits renal beta-lyase, an enzyme that mediates cleavage of mercapturic acid metabolites to toxic products. Since NAG excretion was not elevated in response to DCP with AOA pretreatment and was not raised by pretreatments that deplete glutathione, it is suggested that nephrotoxic effects of DCP may be mediated through the mercapturic acid metabolites on the kidney, rather than due to glutathione depletion per se.