scholarly journals In vitro efficacy of Quillaja saponaria extracts on the infective life‐stage of ectoparasite Caligus rogercresseyi

Author(s):  
Hernán A. Cañon Jones ◽  
Trinidad Schlotterbeck Suarez ◽  
Mario Castillo‐Ruiz ◽  
Hernán Cortes Gonzalez ◽  
Gladys Asencio ◽  
...  
Neuroforum ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Julia Tigges ◽  
Tamara Schikowski ◽  
Ellen Fritsche

Abstract Exposure to environmental pollutants like chemicals or air pollution is major health concern for the human population. Especially the nervous system is a sensitive target for environmental toxins with exposures leading to life stage-dependent neurotoxicity. Developmental and adult neurotoxicity are characterized by specific adverse outcomes ranging from neurodevelopmental disorders to neurodegenerative diseases like Alzheimer’s and Parkinson’s disease. The risk assessment process for human health protection is currently undergoing a paradigm change toward new approach methods that allow mechanism-based toxicity assessment. As a flagship project, an in vitro battery of test methods for developmental neurotoxicity evaluation is currently supported by the Organization for Economic Co-operation and Development (OECD). A plethora of stem cell-based methods including brain spheres and organoids are currently further developed to achieve time- and cost-saving tools for linking MoA-based hazards to adverse health effects observed in humans.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Leda Guzmán ◽  
Katherine Villalón ◽  
María José Marchant ◽  
María Elena Tarnok ◽  
Pilar Cárdenas ◽  
...  

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 201
Author(s):  
Jeremiah Reyes ◽  
Cuauhtemoc Ayala-Chavez ◽  
Arvind Sharma ◽  
Michael Pham ◽  
Andrew B. Nuss ◽  
...  

Ixodes scapularis is the major vector of Lyme disease in the Eastern United States. Each active life stage (larva, nymph, and adult) takes a blood meal either for developing and molting to the next stage (larvae and nymphs) or for oviposition (adult females). This protein-rich blood meal is the only food taken by Ixodes ticks and therefore efficient blood digestion is critical for survival. Studies in partially engorged ticks have shown that the initial stages of digestion are carried out by cathepsin proteases within acidic digestive cells. In this study, we investigated the potential role of serine proteases in blood digestion in replete ticks. RNA interference was used for functional analysis and a trypsin-benzoyl-D, L-arginine 4-nitoanilide assay was used to measure active trypsin levels. Hemoglobinolytic activity was determined in vitro, with or without a serine protease inhibitor. Our data suggest that trypsin levels increase significantly after repletion. Knockdown of serine proteases negatively impacted blood feeding, survival, fecundity, levels of active trypsin in the midgut, and resulted in lower hemoglobin degradation. Incubation of midgut extract with a trypsin inhibitor resulted in 65% lower hemoglobin degradation. We provide evidence of the serine proteases as digestive enzymes in fully engorged, replete females. Understanding the digestive profile of trypsin during blood meal digestion in I. scapularis improves our understanding of the basic biology of ticks and may lead to new methods for tick control.


2007 ◽  
Vol 85 (11) ◽  
pp. 1184-1194 ◽  
Author(s):  
Georgios S. Katselis ◽  
Alberto Estrada ◽  
Dennis K.J. Gorecki ◽  
Branka Barl

Eight pure triterpenoid saponin compounds isolated from the root of Polygala senega L., a plant indigenous to the Canadian prairies, were evaluated for their immunological activity in mouse models. The specific antibody responses of the IgG2a subclass increased significantly when isolated P. senega saponins were used as adjuvants in the immunization of mice with OVA antigen. In addition, increased IL-2 levels were observed in spleen cell cultures from P. senega saponin-immunized mice after in vitro secondary antigen stimulation. The saponins were tested for their toxicity in mice by using a haemolytic activity assay and found to be less toxic than Quillaja saponaria saponins that have long been used as adjuvants in vaccine formulations. This study has shown the potential of P. senega saponins to be considered as a natural source of vaccine adjuvants with biological activity equivalent to the current commercially available saponin adjuvants.


2006 ◽  
Vol 129 (3-4) ◽  
pp. 175-186 ◽  
Author(s):  
B. Pen ◽  
C. Sar ◽  
B. Mwenya ◽  
K. Kuwaki ◽  
R. Morikawa ◽  
...  

2015 ◽  
Vol 6 (2) ◽  
pp. 501-512 ◽  
Author(s):  
Liliya Vinarova ◽  
Zahari Vinarov ◽  
Vasil Atanasov ◽  
Ivayla Pantcheva ◽  
Slavka Tcholakova ◽  
...  

Quillaja saponariaandSapindus trifoliatusextracts decrease cholesterol bioaccessibility duringin vitrodigestion and lower serum cholesterol in mice.


2021 ◽  
Vol 4 ◽  
Author(s):  
Kathrin Blumenstein ◽  
Johanna Bußkamp ◽  
Gitta Jutta Langer ◽  
Rebekka Schlößer ◽  
Natalia Marion Parra Rojas ◽  
...  

The ascomycete Sphaeropsis sapinea is the causal agent of the Diplodia Tip Blight disease on pines and other conifer species. This fungus has a symptomless endophytic life stage. Disease symptoms become visible when trees have been weakened by abiotic stress, usually related to warmer temperatures and drought. Currently, this disease is observed regularly in Scots pine (Pinus sylvestris) sites in parts of Europe, such as Germany, increasing dramatically in the last decade. Changes in climatic conditions will gradually increase the damage caused by this fungus, because it is favored by elevated temperature. Thus, host trees with reduced vitality due to climate change-related environmental stress are expected to be more susceptible to an outbreak of Diplodia Tip Blight disease. There is currently no established and effective method to control S. sapinea. This project aims to reveal the nature of the endophyte community of Scots pine. Utilizing the antagonistic core community of endophytes could serve as a novel tool for disease control. Results from this study provide a starting point for new solutions to improve forest health and counter S. sapinea disease outbreaks. We screened potential antagonistic endophytes against S. sapinea and infected Scots pine seedlings with the most common endophytes and S. sapinea alone and combination. The host was stressed by limiting access to water. The antagonism study revealed 13 possible fungi with the ability to inhibit the growth of S. sapinea in vitro, for example Sydowia polyspora. None of the tested co-infected fungi (Desmazierella acicola, Didymellaceae sp., Microsphaeropsis olivacea, Sydowia polyspora, and Truncatella conorum-piceae) showed strong necrosis development in vivo, even when host stress increased due to drought. However, the infection experiment demonstrated that drought conditions enhance the effect of the disease outbreak, triggering S. sapinea to cause more necrosis in the infected twigs.


2020 ◽  
Author(s):  
Paul McCusker ◽  
Wasim Hussain ◽  
Paul McVeigh ◽  
Erin McCammick ◽  
Nathan G. Clarke ◽  
...  

AbstractFor over a decade RNA interference (RNAi) has been an important molecular tool for functional genomics studies in parasitic flatworms. Despite this, our understanding of RNAi dynamics in many flatworm parasites, such as the temperate liver fluke (Fasciola hepatica), remains rudimentary. The ability to maintain developing juvenile fluke in vitro provides the opportunity to perform functional studies during development of the key pathogenic life stage. Here, we investigate the RNAi competence of developing juvenile liver fluke. Firstly, all life stages examined possess, and express, core candidate RNAi effectors encouraging the hypothesis that all life stages of F. hepatica are RNAi competent. RNAi effector analyses supported growing evidence that parasitic flatworms have evolved a separate clade of RNAi effectors with unknown function. Secondly, we assessed the impact of growth / development during in vitro culture on RNAi in F. hepatica juveniles and found that during the first week post-excystment liver fluke juveniles exhibit quantitatively lower RNAi mediated transcript knockdown when maintained in growth inducing media. This did not appear to occur in older in vitro juveniles, suggesting that rapidly shifting transcript dynamics over the first week following excystment alters RNAi efficacy after a single 24 hour exposure to double stranded (ds)RNA. Finally, RNAi efficiency was found to be improved through use of a repeated dsRNA exposure methodology that has facilitated silencing of genes in a range of tissues, thereby increasing the utility of RNAi as a functional genomics tool in F. hepatica.


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