The disulfide reducing enzymes glutathione reductase and thioredoxin reductase are highly conserved among bacteria, fungi, worms, and mammals. These proteins maintain intracellular redox homeostasis to protect the organism from oxidative damage. Here we demonstrate the absence of glutathione reductase in Drosophila melanogaster, identify a new type of thioredoxin reductase, and provide evidence that a thioredoxin system supports GSSG reduction. Our data suggest that antioxidant defense in Drosophila, and probably in related insects, differs fundamentally from that in other organisms.

Kwashiorkor is a severe edematous form of malnutrition with high prevalence and lethality in many African countries, and repeatedly has been reported to be associated with oxidative stress. The therapy of kwashiorkor is still ineffective. In this pilot study, we tested the hypothesis that oral application of thiol-containing antioxidants increases glutathione status and is beneficial for the clinical recovery of kwashiorkor patients. The longitudinal clinical intervention study was carried out at St Joseph's Hospital, Jirapa, Ghana. Children with severe kwashiorkor were randomly assigned to either a standard treatment (ST) receiving a therapeutic protocol based on the recommendations of the WHO or to one of three study groups receiving in addition 2 x 600 mg reduced glutathione or 2 x 50 mg alpha-lipoic acid or 2 x 100 mg N-acetylcysteine per day. Patients were followed up clinically and biochemically for 20 days and compared with 37 healthy controls. Both glutathione and alpha-lipoic acid supplementation had positive effects on survival. Also, the blood glutathione concentrations correlated positively with survival rates. Furthermore, the initial skin lesions, glutathione and total protein concentrations were found to be strong predictors of survival. The data strongly suggest that a therapy restoring the antioxidative capacity by applying cysteine equivalents in the form of glutathione and/or alpha-lipoic acid is beneficial for biochemical and clinical recovery of kwashiorkor patients.

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Induction of germination by gibberellin or light is not a prerequisite for protein and RNA synthesis in spores of A. phyllitidis. Imbibed but non-induced spores of this fern show a high rate of translation as well as appreciably transcription of all RNA types. The pattern of in-vitro translation of polyadenylated RNA present in the dry spore corresponds with the in-vivo translation products under non-inductive conditions. New proteins are not detectable among the in-vitro and in-vivo translation products until 48 h after a germination stimulus. Although the dark imbibition of spores is accompanied by a reduction in the lengths of polyadenylated tracts of the stored mRNA, this fraction is characterized by a remarkable stability which is undoubtedly a prerequisite for the high viability of these fern spores. The importance of these results for the general meaning of stored mRNA in spore and seed germination processes is discussed.