Nitric oxide (NO) is an important signaling molecule, and a number of NO synthesis inhibitors and scavengers have been developed to allow study of NO functions and to reduce excess NO levels in disease states. We showed previously that cobinamide, a cobalamin (vitamin B 12 ) precursor, binds NO with high affinity, and we now evaluated the potential of cobinamide as a NO scavenger in biologic systems. We found that cobinamide reversed NO-stimulated fluid secretion in Drosophila Malpighian tubules, both when applied in the form of a NO donor and when produced intracellularly by nitricoxide synthase. Moreover, feeding flies cobinamide markedly attenuated subsequent NO-induced increases in tubular fluid secretion. Cobinamide was taken up efficiently by cultured rodent cells and prevented NOinduced phosphorylation of the vasodilator-stimulated phosphoprotein VASP both when NO was provided to the cells and when NO was generated intracellularly. Cobinamide appeared to act via scavenging NO because it reduced nitrite and nitrate concentrations in both the fly and mammalian cell systems, and it did not interfere with cGMP-induced phosphorylation of VASP. In rodent and human cells, cobinamide exhibited toxicity at concentrations >50 M with toxicity completely prevented by providing equimolar amounts of cobalamin. Combining cobalamin with cobinamide had no effect on the ability of cobinamide to scavenge NO. Cobinamide did not inhibit the in vitro activity of either of the two mammalian cobalamin-dependent enzymes, methionine synthase or methylmalonyl-coenzyme A mutase; however, it did inhibit the in vivo activities of the enzymes in the absence, but not presence, of cobalamin, suggesting that cobinamide toxicity was secondary to interference with cobalamin metabolism. As part of these studies, we developed a facile method for producing and purifying cobinamide. We conclude that cobinamide is an effective intra-and extracellular NO scavenger whose modest toxicity can be eliminated by cobalamin.

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Objective: The main aim of our research was to develop an Antifungal cream formulation consisting of Chlorphenesin for the treatment of Fungal infections. Topical route is the most suitable route for skin infections. Methods: The development of topical drug delivery systems designed to have systemic effects appears to be beneficial for a number of drugs on account of several advantages over conventional dosage forms(or) routes of drug administration. An Antifungal cream formulation consisting of Chlorphenesin was prepared. Results: The formulation was subjected to in vitro diffusion studies. Microbiological studies were performed to find out the safety of materials used in the formulation. Conclusion: The developed cream consisting of Cholrphnesin was found to be safe and effective for the treatment of fungal infection.