O-demethylation of dextromethorphan using microbial cultures.

The potential of various microbes to metabolize the dextromethorphan (DXM) , a CYP 2D6 substrate was studied to investigate similarities between microbial and mammalian metabolism. Eight microbes were screened for their ability to metabolize DXM in a manner comparable to humans with a view to develop alternative systems to study human drug metabolism. The major metabolite of DXM produced by Saccharomyces cerevisiae (NCIM 3090) was characterized by HPLC and Liquid Chromatography Mass Spectrometry (LC/MS). DXM was biotransformed by Saccharomyces cerevisiae into a major metabolite dextrorphan which is a known , active metabolite of DXM in human. The microbial metabolism of DXM was similar to the metabolism in mammals. The Saccharomyces cerevisiae could be used as a suitable model strain in vitro to mimic CYP 2D6 metabolism and to produce dextrorphan an active metabolite of DXM for further pharmacological, toxicological studies.

Evaluation of Sesbania grandiflora for antiurolithiatic and antioxidant properties.

In the indigenous system of medicine in India, the plant Sesbania grandiflora is claimed to be useful for various ailments, and one such use is for the treatment of renal calculi. The major purpose of this study is to investigate the potential of S. grandiflora in the treatment of renal calculi. The leaf juice of S. grandiflora was evaluated for median lethal dose, gross behavioral changes, antiurolithiatic and antioxidant activities. The antiurolithiatic activity was evaluated by a calculi-producing diet model, using gentamicin (subcutaneously) and 5% ammonium oxalate in rat feed to induce calcium oxalate-type stones. The parameters monitored in the present study are calcium and oxalate deposition in the kidney, kidney weights, urinary excretion of calcium and oxalate. The in vivo antioxidant parameters lipid peroxidation, glutathione reductase and catalase were monitored. The plant juice was also evaluated for scavenging of nitric oxide and 2-diphenyl-2-picryl hydrazyl free radicals. The leaf juice of S. grandiflora was safe orally and exhibited no gross behavioral changes except for an increase in urination. The leaf juice of S. grandiflora showed significant antiurolithiatic activity against calcium oxalate-type stones and also exhibited antioxidant properties. The results obtained in this study provide evidence for the efficacy of the leaf juice of S. grandiflora as antiurolithiatic agent.