Translation of in vitro cannabinoid 1 receptor agonist activity to in vivo pharmacodynamic endpoints.

Introduction: Building an understanding of in vivo efficacy based on the evaluation of in vitro affinity or potency is critical in expediting early decision making in drug discovery and can significantly reduce the need for animal studies. The aim of the present study was to understand the translation of in vitro to in vivo endpoints for the cannabinoid receptor 1 (CB1).

Methods: Using a selection of CB1 agonists we describe an evaluation of in vitro to in vivo translation comparing in vitro receptor affinity or functional potency, using both cAMP and β-arrestin endpoints, to various in vivo CB1 agonist-associated endpoints.

Incorporation of in vitro techniques for botanicals dietary supplement safety assessment - Towards evaluation of developmental and reproductive toxicity (DART).

As complex mixtures, botanicals present unique challenges when assessing safe use, particularly when endpoint gaps exist that cannot be fully resolved by existing toxicological literature. Here we explore in vitro gene expression as well receptor binding and enzyme activity as alternative assays to inform on developmental and reproductive toxicity (DART) relevant modes of action, since DART data gaps are common for botanicals. Specifically, botanicals suspected to have DART effects, in addition to those with a significant history of use, were tested in these assays.

Dissociation of GDP dissociation inhibitor and membrane translocation are required for efficient activation of Rac by the Dbl homology-pleckstrin homology region of Tiam.

Small G proteins of the Rho/Rac/Cdc42 family are associated with lipid membranes through their prenylated C termini. Alternatively, these proteins form soluble complexes with GDI proteins. To assess how this membrane partitioning influences the activation of Rac by guanine nucleotide exchange factors, GDP-to-GTP exchange reactions were performed in the presence of liposomes using different forms of Rac-GDP.