Fermentation, Isolation, Structure, and antidiabetic activity of NFAT-133 produced by Streptomyces strain PM0324667

Type-2 diabetes is mediated by defects in either insulin secretion or insulin action. In an effort to identify extracts that may stimulate glucose uptake, similar to insulin, a high throughput-screening assay for measuring glucose uptake in skeletal muscle cells was established. During the screening studies to discover novel antidiabetic compounds from microbial resources a Streptomyces strain PM0324667 (MTCC 5543, the Strain accession number at Institute of Microbial Technology, Chandigarh, India), an isolate from arid soil was identified which expressed a secondary metabolite that induced glucose uptake in L6 skeletal muscle cells. By employing bioactivity guided fractionation techniques, a tri-substituted simple aromatic compound with anti-diabetic potential was isolated. It was characterized based on MS and 2D NMR spectral data and identified as NFAT-133 which is a known immunosuppressive agent that inhibits NFAT-dependent transcription in vitro. Our investigations revealed the antidiabetic potential of NFAT-133. The compound induced glucose uptake in differentiated L6 myotubes with an EC50 of 6.3 ± 1.8 μM without activating the peroxisome proliferator-activated receptor-γ. Further, NFAT-133 was also efficacious in vivo in diabetic animals and reduced systemic glucose levels. Thus it is a potential lead compound which can be considered for development as a therapeutic for the treatment of type-2 diabetes. We have reported herewith the isolation of the producer microbe, fermentation, purification, in vitro, and in vivo antidiabetic activity of the compound

Prediction of volume of distribution in preclinical species and humans: application of simplified physiologically based algorithms

<p></p><p>The present study was aimed at developing simplified physiologically based semi-mechanistic algorithms to predict V_ss and interspecies scaling factors to predict tissue-K_ps which require minimum input parameters, diminish the computing complexity and have better predictability.</p><p>V_ss of 86 structurally diverse compounds in preclinical species and 27 compounds in humans were predicted using only lung- and muscle-K_p as inputs. Interspecies scaling factor (s) were developed based on fold-differences in individual tissue lipid contents, relative organ blood flow: relative organ weight ratio between two species. Tissue-K_ps were predicted for 34 compounds using the newly developed interspecies scaling factors.</p><p>The predicted-to-experimental V_ss values for all the 113 compounds was 1.3 ± 0.9 with 83% values being within a factor of two. The tissue-K_ps in rat, dog and human were predicted using experimental tissue-K_p data in rodents and interspecies scaling factors and here also, 83% of tissue-K_ps were within two-fold of the experimental values.</p><p>In conclusion, simplified physiologically based algorithms have been developed to predict both volume of distribution and tissue-K_ps, in which required input parameters as well as computing complexity have been noticeably reduced.</p><p></p> <p>The present study was aimed at developing simplified physiologically based semi-mechanistic algorithms to predict V_ss and interspecies scaling factors to predict tissue-K_ps which require minimum input parameters, diminish the computing complexity and have better predictability.</p> <p>V_ss of 86 structurally diverse compounds in preclinical species and 27 compounds in humans were predicted using only lung- and muscle-K_p as inputs. Interspecies scaling factor (s) were developed based on fold-differences in individual tissue lipid contents, relative organ blood flow: relative organ weight ratio between two species. Tissue-K_ps were predicted for 34 compounds using the newly developed interspecies scaling factors.</p> <p>The predicted-to-experimental V_ss values for all the 113 compounds was 1.3 ± 0.9 with 83% values being within a factor of two. The tissue-K_ps in rat, dog and human were predicted using experimental tissue-K_p data in rodents and interspecies scaling factors and here also, 83% of tissue-K_ps were within two-fold of the experimental values.</p> <p>In conclusion, simplified physiologically based algorithms have been developed to predict both volume of distribution and tissue-K_ps, in which required input parameters as well as computing complexity have been noticeably reduced.</p

The melanocortin-1 receptor gene mediates female-specific mechanisms of analgesia in mice and humans.

Sex specificity of neural mechanisms modulating nociceptive information has been demonstrated in rodents, and these qualitative sex differences appear to be relevant to analgesia from kappa-opioid receptor agonists, a drug class reported to be clinically effective only in women. Via quantitative trait locus mapping followed by a candidate gene strategy using both mutant mice and pharmacological tools, we now demonstrate that the melanocortin-1 receptor (Mc1r) gene mediates kappa-opioid analgesia in female mice only. This finding suggested that individuals with variants of the human MC1R gene, associated in our species with red hair and fair skin, might also display altered kappa-opioid analgesia. We found that women with two variant MC1R alleles displayed significantly greater analgesia from the kappa-opioid, pentazocine, than all other groups. This study demonstrates an unexpected role for the MC1R gene, verifies that pain modulation in the two sexes involves neurochemically distinct substrates, and represents an example of a direct translation of a pharmacogenetic finding from mouse to human

Variable sensitivity to noxious heat is mediated by differential expression of the CGRP gene

Heat sensitivity shows considerable functional variability in humans and laboratory animals, and is fundamental to inflammatory and possibly neuropathic pain. In the mouse, at least, much of this variability is genetic because inbred strains differ robustly in their behavioral sensitivity to noxious heat. These strain differences are shown here to reflect differential responsiveness of primary afferent thermal nociceptors to heat stimuli. We further present convergent behavioral and electrophysiological evidence that the variable responses to noxious heat are due to strain-dependence of CGRP expression and sensitivity. Strain differences in behavioral response to noxious heat could be abolished by peripheral injection of CGRP, blockade of cutaneous and spinal CGRP receptors, or long-term inactivation of CGRP with a CGRP-binding Spiegelmer. Linkage mapping supports the contention that the genetic variant determining variable heat pain sensitivity across mouse strains affects the expression of the Calca gene that codes for CGRPα