Metalloproteases and egg-hatching in Pediculus humanus, the body (clothes) louse of humans (Phthiraptera: Insecta)

Parasitology ◽  
2007 ◽  
Vol 135 (1) ◽  
pp. 125-130 ◽  
Author(s):  
V. M. BOWLES ◽  
A. R. YOUNG ◽  
S. C. BARKER
Keyword(s):  
Protease Activity ◽  
The Body ◽  
Egg Hatching ◽  
Egg Hatch ◽  
Pediculus Humanus ◽  
Sds Page ◽  
Metalloprotease Inhibitors ◽  
Egg Shell ◽  
Ph Range

SUMMARYTo investigate the biochemical components of egg-hatch in the body louse, Pediculus humanus, egg-shell-washings (ESW) were collected during the first 2 h post-hatching and analysed by gelatin SDS-PAGE. These ESW contained proteases with molecular mass in the range of 25–100 kDa; the most abundant proteases were ~25 kDa. The 3 main regions of protease activity in the one-dimensional gelatin SDS-PAGE gels resolved to at least 23 distinct regions of protease activity when analysed by two-dimensional gelatin SDS-PAGE, with iso-electric points spread over the entire 3 to 10 pH range. Mechanistic characterization indicated that the ESW contained proteases of the metallo-class, inhibited by both 1,10-phenanthroline and EDTA. Several protease inhibitors were tested for their ability to inhibit louse egg-hatch in vitro. The metalloprotease inhibitor 1,10-phenanthroline and the aminopeptidase inhibitor bestatin significantly inhibited (P<0·05) louse egg-hatch (100% and 58%, respectively). The presence of metalloproteases at the time of egg-hatch and the inhibition of egg-hatch in P. humanus by metalloprotease inhibitors suggests a crucial role for these proteases in the hatching of this medically important parasite.

In vitro ovicidal and larvicidal activities of some saponins and flavonoids against parasitic nematodes of goats

Parasitology ◽  
2018 ◽  
Vol 145 (14) ◽  
pp. 1884-1889 ◽  
Author(s):  
Acidália Carine Vieira Santos ◽  
Francianne Oliveira Santos ◽  
Hélimar Gonçalves Lima ◽  
Gisele Dias Da Silva ◽  
Rosangela Soares Uzêda ◽  
...  
Keyword(s):  
Anthelmintic Activity ◽  
Gastrointestinal Nematodes ◽  
Parasitic Nematodes ◽  
Egg Hatching ◽  
Egg Hatch ◽  
Low Toxicity ◽  
Larvicidal Activities ◽  
Hecogenin Acetate ◽  
Active Substances

AbstractThis study assessed the anthelmintic activity of plant-derived compounds against gastrointestinal nematodes of goats using the egg hatch and larval motility assays. The compounds tested were saponins (digitonin and aescin) and their respective sapogenins (aglycones), hecogenin acetate and flavonoids (catechin, hesperidin, isocordoin and a mixture of isocordoin and cordoin). Additionally, cytotoxicity of active substances was analysed on Vero cell through 3-4,5-dimethylthiazol-2-yl,2,5diphenyltetrazolium bromide (MTT) and propidium iodide (PI) tests. Significant reduction on the egg hatching (P < 0.05) was seen only in the treatments with aescin (99%/EC50 = 0.67 mg mL−1) and digitonin (45%). The compounds that reduced the larval motility (P < 0.05) were digitonin (EC50 = 0.03 mg mL−1 and EC90 = 0.49 mg mL−1) and the hecogenin acetate (75%). The other sapogenins showed low anthelmintic activity. All the flavonoids showed low ovicidal (4–12%) and larvicidal (10–19%) effects. The aescin and digitonin showed low toxicity in PI test (viable cells >90%). Nevertheless, higher cytotoxicity was observed in the MTT assay, with IC50 of 0.20 mg mL−1 (aescin) and 0.0074 mg mL−1 (digitonin). Aescin and digitonin have a pronounced in vitro anthelmintic effect and the glycone portion of these saponins plays an important role in this activity.

scholarly journals In Vitro Anthelmintic Activity of Crude Extracts of Artemisia herba-alba and Punica granatum against Haemonchus contortus

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Aliyi Hassen Ahmed ◽  
Mebrat Ejo ◽  
Teka Feyera ◽  
Dereje Regassa ◽  
Bahar Mummed ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Anthelmintic Activity ◽  
Punica Granatum ◽  
Limiting Factor ◽  
Egg Hatching ◽  
Traditional Use ◽  
Egg Hatch ◽  
Inhibition Effect ◽  
Crude Extracts

Gastrointestinal nematodes (GINs) are the major limiting factor for the successfulness of livestock production throughout the world. Emergence of resistance strains as well as scarcity and high cost of the currently available drugs has led to the evaluation of other alternative helminth control options, mainly from plants. The current study is aimed at investigating the in vitro anthelmintic efficacy of crude methanolic extracts of two traditionally important medicinal plants, Artemisia herba-alba and Punica granatum, against Haemonchus contortus using adult motility assay (AMA) and egg hatch inhibition assay (EHIA). Four graded concentrations of the extracts were tested for both the AMA (10, 5, 2.5, and 1.25 mg/mg) and EHIA (0.1, 0.25, 0.5, and 1 mg/mL) in replicates. Albendazole and phosphate-buffered saline (AMA) or distilled water (EHIA) were used as the positive and negative controls, respectively. The crude extracts of A. herba-alba and P. granatum exhibited a potential anthelmintic activity at all dose levels in a concentration- and time-dependent fashion. The highest concentration (10 mg/mL) of all the extracts caused a significantly (p<0.05) superior nematocidal activity compared to the negative control. Moreover, significant and concentration-dependent egg hatching inhibition effect was observed from both plant extracts. Maximal (98.67%) egg hatching inhibition effect was exhibited by the flower extract of A. herba-alba at 1 mg/mL concentration. The relative egg hatch inhibition efficacy indicated that both plants caused a significantly (p<0.05) greater egg hatch inhibition within 48 hr of exposure. The current study validated the traditional use of both plants as a natural anthelmintic against H. contortus justifying a need to undertake detail pharmacological and toxicological investigation on both plants.

scholarly journals In Vitro Anthelmintic Activity of Saponins Derived from Medicago spp. Plants against Donkey Gastrointestinal Nematodes

2019 ◽  
Vol 6 (2) ◽  
pp. 35 ◽  
Author(s):  
Michela Maestrini ◽  
Aldo Tava ◽  
Simone Mancini ◽  
Federica Salari ◽  
Stefania Perrucci
Keyword(s):  
Anthelmintic Activity ◽  
Gastrointestinal Nematodes ◽  
Deionized Water ◽  
Chemical Compositions ◽  
Egg Hatching ◽  
Egg Hatch ◽  
Reference Drug ◽  
Fecal Samples ◽  
Nematode Eggs

With the aim to find new effective natural compounds for the control of nematodes, the in vitro anthelminthic properties of purified 1% saponins showing different chemical compositions and derived from Medicago sativa (MS), Medicago arborea (MA), Medicago polymorpha cultivar ‘Santiago’ (MPS), M. polymorpha cultivar ‘Anglona’ (MPA), and 1% prosapogenins from M. sativa (MSp), were evaluated and compared. As a source of nematode eggs, pooled fresh fecal samples taken from dairy donkeys naturally infected by gastrointestinal nematodes were used. From fecal samples, eggs were recovered, suspended in deionized water, and used immediately in the bioassay (egg hatch test). The activity of the tested compounds was compared to positive (0.1% thiabendazole) and negative (deionized water and 1% DMSO) controls. All experiments were repeated in triplicate and the obtained data were statistically analyzed. All the tested plant compounds caused a significant (p < 0.05) inhibition of nematode egg hatching (>80%). Moreover, all saponins and prosapogenins showed in vitro anthelmintic properties statistically comparable to that of the reference drug (p < 0.05), except for MPS extract. Obtained results showed that the different Medicago saponins evaluated in this study possess high anthelmintic properties against gastrointestinal nematodes of dairy donkeys, although to a different extent depending on their composition.

scholarly journals In Vitro Anthelmintic Activity of Crude Extracts of Aerial Parts of Cissus quadrangularis L. and Leaves of Schinus molle L. against Haemonchus contortus

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Selamawit Zenebe ◽  
Teka Feyera ◽  
Solomon Assefa
Keyword(s):  
Haemonchus Contortus ◽  
Anthelmintic Activity ◽  
Inhibitory Effects ◽  
Egg Hatching ◽  
Egg Hatch ◽  
Schinus Molle ◽  
Methanolic Extracts ◽  
Aerial Parts ◽  
Cissus Quadrangularis

Background. Haemonchus contortus, the causative agent of Haemonchosis, is the most economically important parasite in small ruminant production. Control with chemotherapy has not been successful due to rapid emergence of drug-resistant strains. There is a continuous search for alternative leads particularly from plants. The study aimed to evaluate the anthelmintic activity of crude methanolic extracts of leaves of Schinus molle and aerial parts of Cissus quadrangularis against H. contortus. Methods. Adult motility test and egg hatching inhibition assay were employed to investigate the in vitro adulticidal and egg hatching inhibitory effects of the extracts. Results. Higher concentrations of the extracts (10 and 5 mg/ml) had a significantly superior adulticidal activity (p<0.05) compared to the negative control and lower concentration levels, which was comparable to albendazole. Similarly, the relative egg hatch inhibition efficacy of S. molle and C. quadrangularis extracts indicated a maximum of 96% and 88% egg hatch inhibition, respectively, within the 48 hrs of exposure at 1 mg/ml. Conclusion. The current study evidenced that the crude methanolic extracts of the plants have promising adulticidal and egg hatching inhibitory effects against H. contortus.

scholarly journals Chemical analyses and evaluation of the anthelmintic effects of Origanum majorana essential oil, in vitro and in vivo studies

2020 ◽  
Vol 65 (No. 11) ◽  
pp. 495-505
Author(s):  
A Abidi ◽  
E Sebai ◽  
M Dhibi ◽  
MA Darghouth ◽  
H Akkari
Keyword(s):  
Essential Oil ◽  
Adult Worm ◽  
Gastrointestinal Nematodes ◽  
Chemical Analyses ◽  
Ovicidal Activity ◽  
Worm Count ◽  
Egg Hatching ◽  
Egg Hatch ◽  
Different Doses

Because of the development of resistance in helminths against major anthelmintic drugs, the search for alternatives is necessary. Medicinal plants are being studied as an alternative source of anthelmintics against gastrointestinal nematodes. The objective of this study is to analyse the chemical composition and evaluate the anthelmintic efficacy of Origanum majorana essential oil. The determination of the chemical composition by gas chromatography/mass chromatography (GC/MS) revealed that the essential oil was dominated by terpenoids, particularly carvacrol (35.65%) and terpenic hydrocarbons p-cymene (15.82%). The in vitro anthelmintic effects against Haemonchus contortus were assessed by an egg hatch assay (EHA) and an adult worm motility assay (AWMA) compared with the reference drug albendazole. The essential oil showed ovicidal activity at all the tested concentrations (1, 2, 4 and 8 mg/ml) and more than 80% egg hatching inhibition was observed at the highest dose (8 mg/ml). Exposure to 0.5 mg/ml of the essential oil for eight hours induced a 50% inhibition in the worm motility. The in vivo study was performed on H. polygyrus by measuring the egg count reduction (ECR) and adult worm count reduction (AWCR) following the treatment of the animals with different doses (2 000, 4 000 and 5 000 mg/kg) of the plant essential oil, and 22 mg/kg of albendazole as the positive control. The results showed that 5 000 mg/kg of the essential oil inhibited the egg count and adult worm count by 76.3 and 74.0%, respectively, seven days post treatment. These findings support the possible use of O. majorana essential oil to control gastrointestinal nematodes.

scholarly journals Anthelminthic effects of extracts of indigenous browses from mid rift valley of Ethiopia

2021 ◽  
Vol 25 (2) ◽  
pp. 132-143
Author(s):  
Amsalu Sisay ◽  
Tegene Negesse ◽  
Ajebu Nurfeta
Keyword(s):  
Developmental Stages ◽  
Negative Control ◽  
In Vitro Assays ◽  
Inhibition Assay ◽  
Egg Hatching ◽  
Acacia Senegal ◽  
Egg Hatch ◽  
Infective Larvae

This study was conducted to evaluate the potential anthelminthic properties of extracts of leaves of indigenous browses (Acacia seyal, Acacia senegal, Acacia tortilis, Millettia ferruginea, and Vernonia amygadalina) based on three in vitro assays. Acetone extracts of browses at different concentrations (75 to 1200 μg/ml, for egg and larvae and 100mg/ml for an adult) were tested on three developmental stages of Haemonchus contortus (eggs, infective larvae, and adult worms) using egg hatch assay (EHA), larval migration inhibition assay (LMIA) and adult worm motility inhibition assay (AMIA). Significant effects were obtained with all five browses but differences were observed depending on the parasitic stages. The effects of five browse extracts on egg hatching were concentration-dependent, the highest (P<0.05) egg hatch inhibition rate was observed at 1200 μg/ml concentration for all browses. All extracts had a higher effect (P<0.01) than that of the negative control, phosphate buffer saline (PBS). In contrast, no concentration-response relationship was found for infective larvae and adult worms, although more potent effects were observed with the highest concentrations. The LMI rate (70%) induced by Vernonia  amygadalina extract, at a concentration of 300 μg/ml, was the highest (P<0.05) of all other browses, even at higher concentrations. The highest LMI rate (62%) induced by Acacia senegal extract at higher concentration, was lower than that of LMI rate (70%) induced by Vernonia amygadalina, at 300 μg/ml concentration. Vernonia amygadalina was found to be highly and rapidly effective against adult worms inducing the highest mortality rate (90%) as soon as 4 hrs after incubation. Overall, the in vitro results suggest that these five  browses do possess anti-parasitic properties and Vernonia amygadalina showed the most effective anti-parasitic property. These effects remain to be confirmed through in vivo study.

Theileria annulata-infected cells produce abundant proteases whose activity is reduced by long-term cell culture

Parasitology ◽  
1992 ◽  
Vol 105 (3) ◽  
pp. 417-423 ◽  
Author(s):  
H. A. Baylis ◽  
A. Megson ◽  
C. G. D. Brown ◽  
G. F. Wilkie ◽  
R. Hall
Keyword(s):  
Protease Activity ◽  
Temperature Shift ◽  
Theileria Annulata ◽  
Absolute Requirement ◽  
Gradual Process ◽  
Sds Page ◽  
Late Passage ◽  
Infected Cells

SUMMARYLysates ofTheileria annulata-infected bovine lymphoblastoid cells and their uninfected counterparts were tested for protease activity using gelatin substrate SDS–PAGE. The infected cells produced a number of extra activities at pH 8·0 in the presence of Ca2+. Calcium was found to enhance the activites but was not an absolute requirement. Studies using inhibitors, including E64, 3,4-dichloroisocoumarin, pepstatin and 1, 10-phenanthroline suggested that the activities were metalloproteases. We analysed two vaccine lines; the Ode line from India and the Ankara Pendik line from Turkey. In the Ode line the later passage had very much reduced levels of the enzyme activities. In the case of the Ankara Pendik line both stages analysed had very low protease activities, but a reduction from the early to late passage was also observed. The reduction in the level of protease activity was also observed as a gradual process during on-going culture of lines derived from the Hissar and Ode stocks. In the Ode line we demonstrated a parallel decrease in the production of microschizonts upon temperature shiftin vitro.

scholarly journals Biology and predatory attributes of a diplogasterid nematode, Fictor composticola Khan et al., 2008

2015 ◽  
Vol 52 (1) ◽  
pp. 50-57 ◽  
Author(s):  
H. K. Bajaj ◽  
R. S. Kanwar
Keyword(s):  
Body Wall ◽  
The Body ◽  
Button Mushroom ◽  
Intestinal Contents ◽  
Aphelenchus Avenae ◽  
Stage Juvenile ◽  
Oesophageal Bulb ◽  
Biocontrol Potential ◽  
Egg Shell

Summary Biology of Fictor composticola has been studied on Aphelenchus avenae in vitro. It reproduces by amphimixis, embryonic development is completed in 24 - 27 h and life cycle in 3 - 4 days. Fusion of sperm and egg pronuclei occurs in the uteri. Pulsation of median oesophageal bulb and pressing of lips against egg shell is seen just prior to hatching but teeth seem to play no role in this process. No moulting occurs inside the egg shell and the first stage juvenile hatches out. Female and male undergo mating upon addition of water in the culture plates and continue to swim in copula for a considerable time. A female lays 1.6 - 4.0 eggs in 24 h while feeding upon A. radicicolus. Predation and reproduction is affected by the temperature and 25 - 35 °C is the optimum range for these phenomena. Process of feeding as recorded with a CCTV attached to a compound microscope is described. F. composticola engulfs small preys; sucks the intestinal contents while holding them or cuts the body wall of large-sized preys and then feeds on prolapsed organs. Two sexes differ in their efficiencies of predation, a female on an average kills 53 A. avenae as compared to 11 by a male in 24 h. F. composticola feeds and reproduces on mycophagous nematodes and juveniles of root- knot, cyst and citrus nematodes but does not prey upon adult nematodes having coarsely annulated cuticle. Cannibalism in this species is also observed. F. composticola and Seinura paratenuicaudata prey upon each other. Biocontrol potential of F. composticola for managing nematode problems in button mushroom and agricultural crops has also been discussed.

scholarly journals Management and Treatment of Human Lice

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Abdoul Karim Sangaré ◽  
Ogobara K. Doumbo ◽  
Didier Raoult
Keyword(s):  
Treatment Strategies ◽  
Review Literature ◽  
The Body ◽  
Controlled Clinical Trials ◽  
Pediculus Humanus ◽  
Literature Searches ◽  
New Treatment ◽  
High Standards ◽  
New Strategies

Of the three lice (head, body, and pubic louse) that infest humans, the body louse is the species involved in epidemics of louse-borne typhus, trench fever, and relapsing fever, but all the three cause pediculosis. Their infestations occur today in many countries despite great efforts to maintain high standards of public health. In this review, literature searches were performed through PubMed, Medline, Google Scholar, and EBSCOhost, with key search words of “Pediculus humanus”, “lice infestation”, “pediculosis”, and “treatment”; and controlled clinical trials were viewed with great interest. Removing lice by hand or with a lice comb, heating infested clothing, and shaving the scalp were some of the oldest methods of controlling human lice. Despite the introduction of other resources including cresol, naphthalene, sulfur, mercury, vinegar, petroleum, and insecticides, the numbers of lice infestation cases and resistance have increased. To date, viable alternative treatments to replace insecticides have been developed experimentallyin vitro. Today, the development of new treatment strategies such as symbiotic treatment and synergistic treatment (antibiotics + ivermectin)in vitrohas proved effective and is promising. Here, we present an overview on managing and treating human lice and highlight new strategies to more effectively fight pediculosis and prevent resistance.

scholarly journals Effects of different extracts of three Annona species on egg-hatching processes of Haemonchus contortus

2019 ◽  
Vol 94 ◽  
Author(s):  
G.S. Castañeda-Ramírez ◽  
J.F.J. Torres-Acosta ◽  
P. Mendoza-de-Gives ◽  
J. Tun-Garrido ◽  
J.A. Rosado-Aguilar ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Methanolic Extract ◽  
Ovicidal Activity ◽  
Leaf Extracts ◽  
Egg Hatching ◽  
Egg Hatch ◽  
Methanolic Extracts ◽  
Morula Stage

Abstract This study assessed the in vitro anthelmintic (AH) activity of methanol and acetone:water leaf extracts from Annona squamosa, A. muricata and A. reticulata against Haemonchus contortus eggs. The egg hatch test was used to determine the effective concentrations required to inhibit 50% of eggs hatching (EC50). The role of polyphenols on AH activity was measured through bioassays with and without polyvinylpolypyrrolidone (PVPP). Methanolic extracts mainly caused the death of eggs at the morula stage (ovicidal activity). Meanwhile, acetone:water extracts caused egg-hatching failure of developed larvae (larvae failing eclosion (LFE) activity). The lowest EC50 values against H. contortus eggs were observed for the methanolic extracts from A. reticulata and A. muricata (274.2 and 382.9 µg/ml, respectively). From the six extracts evaluated, the methanolic extracts of A. muricata, A. reticulata and A. squamosa showed the highest ovicidal activity, resulting in 98.9%, 92.8% and 95.1% egg mortality, respectively. When the methanolic extract of A. squamosa was incubated with PVPP, its AH activity increased. Similarly, when acetone:water extracts of A. muriata and A. reticulata were incubated with PVPP, their LFE activity increased. Alkaloids were only evident in methanolic extracts, irrespective of PVPP incubation. The presence of acetogenins was not observed. In conclusion, methanolic extracts obtained from leaves of A. muricata, A. reticulata and A. squamosa showed ovicidal activity affecting the morula of H. contortus eggs, with minor LFE activity. Meanwhile, acetone:water extracts showed mostly LFE activity, with a lower proportion of ovicidal activity.

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