Glycyrrhizic acid inhibits virus growth and inactivates virus particles.

Screening investigations in antiviral action of plant extracts have revealed that a component of Glycyrrhiza glabra roots, found to be glycyrrhizie acid, is active against viruses. We report here that this drug inhibits growth and cytopathology of several unrelated DNA and RNA viruses, while not affecting cell activity and ability to replicate. In addition, glycyrrhizic acid inactivates herpes simplex virus particles irreversibly.     

On the inhibitory effect of 2-amino-4,6-dichloropyrimidine on growth of vaccinia virus.

2-Amino-4,6-dichloropyrimidine prevents maturation of Vaccinia virus. Proteins synthesized in the presence of the drug are not assembled into virions.     

The antimitotic drug 4,6-dimethyl-2-amino-3,4,5-trimethoxyphenyl-pyrimidine inhibits the nucleoside transport system of cells from various animal species

4,6-dimethyl-2-amino-3,4,5-trimethoxyphenyl-pyrimidine (B-31) is a pyrimidine derivative previously reported to arrest the mitotic cycle of mammalian cells in metaphase. In the present study it is shown that B-31 also acts as a specific inhibitor of the cellular uptake of nucleosides. The uptake of purinic and pyrimidinic nucleosides is inhibited by 80–90% at concentrations in the range 5–20 μg/ml, whereas those of nucleobases, leucine, choline and glucose are unaltered at the maximum nontoxic dose of B-31 (25 μg/ml). Various mammalian (human, monkey and murine) and avian cell are equally sensitive to the inhibition of nucleoside transport. The antimitotic effect of B-31, by contrast, is species-specific: human cells are the most sensitive whereas monkey and chicken fibroblasts appear resistant to this effect. Both effects can be reversed by removal of B-31 from the medium; inhibition of nucleoside transport can also be reversed by high doses of the nucleosides themselves.     

Protection by cerium chloride on CCl4-induced hepatotoxicity

Summary Pretreatment of rats with cerium chloride, an inhibitor of the DMES, protects against CCl₄ intoxication. The protection was obtained against the fatty infiltration in the liver, the decrease of triglyceride secretion from the liver into the plasma compartment, the polysomal disaggregation and the rise of serum transaminases.     

Relationship between DNA and cholesterol synthesis in kidney after refeeding

Summary DNA and cholesterol synthesis were investigated in the kidneys of fasted-refed rats. Refeeding resulted in an increase in kidney DNA synthesis, as measured by³H-thymidine incorporation, starting at 72 h. The increase in DNA synthesis was accompanied by a stimulation of cholesterol synthesis, as measured by¹⁴C-acetate incorporation into cholesterol.     

Darier’s disease: a calcium-signaling perspective

Ca²⁺ influx evoked across the plasma membrane upon internal store depletion is essential for a myriad of cellular functions including gene expression, cell proliferation, differentiation and even apoptosis. Darier’s disease (DD), an autosomal dominant inherited disorder of the skin, arising due to mutations in the isoform 2 of the sarco (endo) plasmic reticulum Ca²⁺ ATPase (SERCA2), exemplifies an anomaly of Ca²⁺ signaling disturbances. Owing to loss of function mutations in SERCA2, keratinocytes in DD patients have a reduced pool of endoplasmic reticulum (ER) Ca²⁺. Importantly, the status of ER Ca²⁺ is critical for the activation of a class of plasma membrane Ca²⁺ channels referred to as store operated Ca²⁺ channels (SOCs). The widely expressed transient receptor potential (TRP) family of channels is proposed to be SOCs. In this review we discuss DD from the viewpoint of Ca²⁺ signaling and present a potential role for TRPC1 in the disease pathogenesis. Received 30 August 2007; received after revision 17 October 2007; accepted 6 November 2007     

Protection by cerium chloride on CCl4-induced hepatotoxicity.

Pretreatment of rats with cerium chloride, an inhibitor of the DMES, protect against CCl4 intoxication. The protection was obtained against the fatty infiltration in the liver, the decrease of triglyceride secretion from the liver into the plasma compartment, the polysomal disaggregation and the rise of serum transaminases.     

Antimicrobial and antiviral activity of xylosyl-methylthio-adenosine, a naturally occurring analogue of methylthio-adenosine from Doris verrucosa.

Xylosyl-methylthio-adenosine, a naturally occurring analogue of 5'-deoxy-5'-methylthio-adenosine, has been postulated to play a protective role during egg development in the mollusc Doris verrucosa. However, in vitro tests showed that this analogue is devoid of activity against fungi, bacteria and viruses.