alpha-Amanitin acts in vitro as a selective inhibitor of the nucleoplasmic form B RNA polymerases. Treatment of Chinese hamster ovary (CHO) cells with this drug leads principally to a severe fragmentation of the nucleoli. While the ultrastructural lesions induced by alpha-amanitin in CHO cells and in rat or mouse liver are quite similar, the results diverge concerning the effect on RNA synthesi...

Alpha amanitin and phalloidin are powerful hepatotoxins that belong to the main classes of toxins namely, amatoxins and phallotoxins, isolated from the deadly poisonous mushroom Amanita phalloides. It is well known that disruptions of antioxidant enzyme defense that include superoxide dismutase (SOD), catalase, glutathione peroxidase lead to generation of reactive oxygen species, followed by in...

Alpha-amanitin is considered to be the main toxin present in mushroom species of Amanita phalloides and it possibly most deadly all amatoxins. The aim this study was test whether nanocurcumin could revert hepatic damage experimentally induced rats, tested with following protocols: Group I served as negative control group (PBS @1ml/kg p.o), II positive (α-AMA @0.2 ml/kg p.o single dose), III Sta...

objectives we aimed to investigate whether there is renal injury and its relationship with oxidative stress after intraperitoneal injection of α-ama in mice experimental poisoning models. materials and methods there were 37 male balb/c laboratory mice treated with α-ama, according to the study groups: control group (n = 7); low dose (0.2 mg/kg) (n = 10); moderate dose (0.6 mg/kg) (n = 10), and ...

Mushroom foraging is very popular in some regions of the world. Sometimes toxic and edible mushrooms are mistaken by mushroom collectors, leading to serious human poisoning. The group of mushrooms highly dangerous for human health includes Amanita phalloides. This mushroom produces a toxic octapeptide called α-amanitin which is an inhibitor of nuclear RNA polymerase II. The inhibition of this p...

We investigated the mechanisms of mushroom toxin resistance in the Drosophila Genetic Reference Panel (DGRP) fly lines, using genome-wide association studies (GWAS). While Drosophila melanogaster avoids mushrooms in nature, some lines are surprisingly resistant to α-amanitin-a toxin found solely in mushrooms. This resistance may represent a pre-adaptation, which might enable this species to inv...

Behavioural adaptations of hosts to their parasites form an important component of the evolutionary dynamics of host-parasite interactions. As mushroom-feeding Drosophila can tolerate deadly mycotoxins, but their Howardula nematode parasites cannot, we asked how consuming the potent mycotoxin α-amanitin has affected this host-parasite interaction. We used the fly D. putrida and its parasite H. ...

Autographa californica nuclear polyhedrosis virus-specific RNA synthesis in isolated nuclei of Spodoptera frugiperda cells in culture was monitored at different times postinfection. Up to 8 h postinfection viral RNA synthesis remained sensitive to 5 mug of alpha-amanitin per ml. During the course of infection this sensitivity decreased, and at 24 h postinfection RNA synthesis was completely res...

We have analysed early transcription in devitellinized, cultured embryos of the nematode Caenorhabditis elegans by two methods: measurement of [32P]UTP uptake into TCA-precipitable material and autoradiographic detection of [3H]UTP labelling both in the presence and absence of alpha-amanitin. RNA synthesis was first detected at the 8- to 12-cell stage, and alpha-amanitin sensitivity also appear...

Transcription of the predominant surface antigen genes in Trypanosoma brucei is unusual in its resistance to the RNA polymerase inhibitor alpha-amanitin, a property typical for rDNA transcription in eukaryotes. Transcription of most other protein-coding genes in trypanosomes is sensitive to alpha-amanitin. To investigate whether RNA polymerase I, the polymerase that transcribes rRNA genes, can ...