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Journal of Pesticide Science,
1984]
Juveniles of Caenorhabditis elegans were transformed to dumpy in the media containing methomyl (10 ug/ml) or aldoxycarb (500 ug/ml), but not in the media containing methylisothiocyanate (MITC). The dumpy did not recover to its normal structure even after being transferred to fresh medium, but underwent to adulthood with a lower reproduction rate. The progeny from the dumpy forms was normal in structure, however, its reproductivity was as low as one-third of normal ones. Longevity of the dumpy form and its progeny were longer than those of normal worms. Methomyl (1 ug/ml), MITC (1 ug/ml) and aldoxycarb (10 ug/ml) did not suppress population growth, but MITC (10 ug/ml) did for the first two weeks. The population growth was markedly suppressed at 100 ug/ml of methomyl, 20 ug/ml of MITC and 1000 ug/ml of aldoxycarb.
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Sci Total Environ,
2020]
The Deepwater Horizon (DWH) oil spill marked the largest environmental oil spill in human history, where it was estimated a large amount of the polycyclic aromatic hydrocarbons (PAHs) were released with crude oil into the environment. In this study, common PAH compounds were quantitatively determined in crude oil from the DWH spill by gas chromatography-mass spectroscopy (GC-MS). Twelve PAH compounds were identified and quantified from a 100x dilution of DWH crude oil: naphthalene (7800ng/mL), acenaphthylene (590ng/mL), acenaphtehen (540ng/mL), fluorene (2550ng/mL), phenanthrene (2910ng/mL), anthracene (840ng/mL), fluoranthene (490ng/mL), pyrene (290ng/mL), benzo(k) fluoranthene (1050ng/mL), benzo(b)fluoranthene (1360ng/mL), dibenz(a,h)anthracene (2560ng/mL), and benzo(g, h, i) perylene (630ng/mL). Toxicity assays using the nematode, Caenorhabditis elegans (C. elegans), indicated a single PAH compound naphthalene, exposure increased C. elegans germ cell apoptosis which may adversely affect progeny reproduction. The number of apoptotic germ cells significantly increased from 1.4 to 2.5 when worms were treated with 10g/mL of naphthalene and from 1.3 to 2.5 and 3.5 cells in presence of 1g/mL and 5g/mL of benzo(a)pyrene, respectively. Five CYP450 genes (CYP14A3, CYP35A1, CYP35A2, CYP35A5, and CYP35C1) were significantly upregulated following 500x dilution of dispersed crude oil exposure (p<0.05). These results suggest that CYP450s may play a role in bioactivation of PAHs in crude oil, resulting in DNA damage related germ cell apoptosis.
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Nematologica,
1983]
The quantities of Mg+2, Na+, K+, Mn+2, Ca+2 and Cu+2 required by the free-living nematode C. elegans were determined. An individual mineral deficieny was developed by deleting the mineral from the basal medium. Quantitative requirements of individual minerals were determined respectively by adding each mineral at various concentrations to the depleted medium. Serial subcultures and biological pre-treated media were used for the development of Mn+2, Ca+2 and Cu+2 deficiencies. It was found that most C. elegans were supported at 73 ug/ml Mg+2, 300 ug/ml Na+, 530 Ug/ml K+, 6.3 ug/ml Mn+2, 1500 ug/ml Ca+2 and 7.2 ug/ml Cu+2.
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Nematologica,
1993]
The carbohydrate requirement in the free-living nematode Caenorhabditis elegans was investigated. Glucose, fructose, sucrose, trehalose and glycogen were tested individually at concentrations of 0, 1.3, 6.5, 32.5, and 162.5 mg/ml as the energy source in a chemically defined medium containing C . briggsae Maintenance Medium (CbMM without glucose), 50 .mu.g/ml cytochrome c and 50 .mu.g/ml .beta.-sitosterol. Potassium acetate, used as the energy source in other studies, was not added to the medium. Therefore, carbohydrate was the major energy source for the nematode. At 32.5 mg/ml, glucose was found to support the maximal population at 80,000 nematodes/ml (100%), followed by glycogen (96%) and trehalose (73%). Population was significantly reduced when fructose (46%) or sucrose (26%) was the carbohydrate source. Toxicity was shown at 162.5 mg/ml for four carbohydrates tested, except glycogen. These results suggested that all five carbohydrates can be utilized as energy sources by C . elegans ; however, the degree of utilization of each carbohydate by C . elegans varied. Since glucose was best utilized by the nematode at 32.5 mg/ml, this concentration is recommended for future use in preparation in CbMM. Based on this study, the chemically defined medium that has been used for cultivation of C . elegans can also be modified to: CbMM (1x, with 32.5 mg/ml glucose), 50 .mu./ml cytochrome c and .mu.g/ml .beta.-sitosterol. Glucose (at 32.5 mg/ml) can be used as the major energy source in a chemically defined medium for the axenic cultivation of C . elegans .
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Int J Parasitol Drugs Drug Resist,
2016]
Macrocyclic lactones (ML) are important anthelmintics used in animals and humans against parasite nematodes, but their therapeutic success is compromised by the spread of ML resistance. Some ABC transporters, such as p-glycoproteins (Pgps), are selected and overexpressed in ML-resistant nematodes, supporting a role for some drug efflux proteins in ML resistance. However, the role of such proteins in ML transport remains to be clarified at the molecular level. Recently, Caenorhabditis elegans Pgp-1 (Cel-Pgp-1) has been crystallized, and its drug-modulated ATPase function characterized invitro revealed Cel-Pgp-1 as a multidrug transporter. Using this crystal structure, we have developed an in silico drug docking model in order to study the binding of ML and other anthelmintic drugs to Cel-Pgp-1. All tested ML bound with high affinity in a unique site, within the inner chamber of the protein, supporting that ML may be transported by Cel-Pgp-1. Interestingly, interacting residues delineate a ML specific fingerprint involving H-bonds, including T1028. In particular, benzofurane and spiroketal moieties bound to specific sub-sites. When compared with the aglycone ML, such as moxidectin and ivermectin aglycone, avermectin anthelmintics have significant higher affinity for Cel-Pgp-1, likely due to the sugar substituent(s) that bind to a specific area involving H-bonds at Y771. Triclabendazole, closantel and emodepside bound with good affinities to different sub-sites in the inner chamber, partially overlapping with the ML binding site, suggesting that they could compete for Cel-Pgp-1-mediated ML transport. In conclusion, this work provides novel information on the role of nematode Pgps in transporting anthelmintics, and a valuable tool to predict drug-drug interactions and to rationally design new competitive inhibitors of clinically-relevant nematode Pgps, to improve anthelmintic therapeutics.
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Bios,
1997]
Isolated eggs of the free-living nematode Caenorhabditis elegans and parasitic nematode Haemonchus contortus were tested for susceptibility to ivermectin, a proven antiparasitic agent. Ivermectin inhibited hatching of C. elegans eggs at the highest concentration tested (400 ug/ml). At an intermediate concentration (100 ug/ml), hatching was permitted, but all of the newly hatched first-stage larvae were killed by the drug. At lower concentrations (25 ug/ml and 6.25 ug/ml), the drug permitted hatching and survival of more than 85% of the first-stage larvae. The control eggs and first-stage larvae displayed a similarly high viability. A replicate experiment using the parasitic nematode H. contortus showed similar results, but a somewhat greater sensitivity to the drug. At the highest level tested (400 ug/ml), the eggs did not embryonate and so did not hatch. At 100 ug/ml, they embryonated but did not hatch. At a concentration of 25 ug/ml, hatching was slightly inhibited in comparison to the controls and motility of the newly hatched first-stage larvae was judged to be impaired. Eggs exposed to the lowest concentration (6.25 ug/ml), like the control eggs, had a hatching rate of greater than 85%, with no locomotor impairment. Thiabendazole, used as a positive control, caused complete blockade of embryonation.
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Mech Ageing Dev,
1988]
Vitamin E extends the lifespan of many animals, including the nematode Caenorhabditis elegans. Our results confirm previous studies that 200 micrograms/ml vitamin E significantly prolonged C. elegans survival (17-23%, P less than 0.05) when added from hatching to day 3, while continuous exposure, either at hatching or from 4 days prior to hatching, had little additional effect. Treatment with 100 or 400 micrograms/ml vitamin E, or with other antioxidants (80 micrograms/ml vitamin C, either alone or in combination with vitamin E, or 120 micrograms/ml N,N'-diphenyl-1,4-diphenylenediamine (DPPD] did not significantly affect lifespan. All treatments with 200 micrograms/ml vitamin E moderately reduced fecundity (total progeny) and increased the mean day of reproduction. At 400 micrograms/ml, vitamin E had severe effects, while DPPD, vitamin C, and 100 micrograms/ml vitamin E had slight effects on both these parameters of reproduction. These data suggest that vitamin E increases lifespan in C. elegans in part by slowing development in the same manner that metabolic-depressant or mildly cytotoxic drugs increase lifespan, decrease fecundity, and delay the timing of reproduction.
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Indian J Exp Biol,
2015]
Advanced Glycation End products (AGE) generated in a non enzymatic protein glycation process are frequently associated with diabetes, aging and other chronic diseases. Here, we explored the protective effect of phlorotannins from brown algae Padina pavonica, Sargassum polycystum and Turbinaria ornata against AGEs formation. Phlorotannins were extracted from brown algae with methanol and its purity was analyzed by TLC and RP-HPLC-DAD. Twenty five grams of P. pavonica, S. polycystum, T. ornata yielded 27.6 +/- 0.8 g/ml, 37.7 g/ml and 37.1 +/- 0.74 g/ml of phloroglucinol equivalent of phlorotannins, respectively. Antioxidant potentials were examined through DPPH assay and their IC50 values were P. pavonica (30.12 +/- 0.99 g), S. polycystum (40.9 +/- 1.2 g) and T. ornata (22.9 +/- 1.3 g), which was comparatively lesser than the control ascorbic acid (46 +/- 0.2 g). Further, anti-AGE activity was examined in vitro by BSA-glucose assay with the extracted phlorotannins of brown algae (P. pavonica, 15.16 +/- 0.26 g/ml; S. polycystum, 35.245 +/- 2.3 g/ml; T. ornata, 22.7 +/- 0.3 g/ml), which revealed the required concentration to inhibit 50% of albumin glycation (IC50) were lower for extracts than controls (phloroglucinol, 222.33 +/- 4.9 g/ml; thiamine, 263 g/ml). Furthermore, brown algal extracts containing phlorotannins (100 l) exhibited protective effects against AGE formation in vivo in C. elegans with induced hyperglycemia.
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Int J Antimicrob Agents,
2017]
The antimicrobial activity and toxicity to nematodes of the cyclam salt [H2{H2((4-CF)3PhCH2)2Cyclam}](CH3COO)2.(CH3COOH)2 was evaluated. Estimated minimum inhibitory concentrations (MICs) of 9, 261 and 15 g/mL were obtained for Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, respectively. For selected Candida spp., the estimated MICs obtained ranged from 32 g/mL to 63 g/mL. Bactericidal activity was demonstrated but the compound was not reliably fungicidal. Concentrations of the cyclam salt up to 32 g/mL did not significantly affect survival of the nematode Caenorhabditis elegans; however, concentrations equal or above this value significantly affected nematode survival in a dose-dependent manner.
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Bioorg Med Chem Lett,
2011]
A novel macrocyclic lactone (1) was isolated from the fermentation broth of Streptomycesmicroflavus neau3, and the structure was elucidated by extensive spectroscopic analysis. Compound 1 showed high acaricidal activity against adult mites (IC(50)=11.1 g mL(-1)), and nematocidal activity against Caenorhabditis elegans (IC(50)=17.4 g mL(-1)), especially the acaricidal activity against mite eggs with an IC(50) of 37.1 g mL(-1), which was relative higher than that of the commercial acaricide and nematocide milbemycins A(3)/A(4).