Structure-activity relationships of serotonin 5-HT7 receptors ligands: A review.

5-HT7 receptors are the most recently discovered serotonergic receptors, for which numerous physiological implications in the central and the peripheral nervous systems as well as the endocrine system are described. A current public health challenge is to propose new and more efficient treatments against neuropsychiatric disorders such as epilepsy or Alzheimer's disease. In this context, 5-HT7 receptors represent an interesting target for the treatment and prevention of those pathologies, as an alternative or in association with other medicines. Thus, numerous chemical series of agonists and antagonists have been developed. Some of these molecules have shown a therapeutic potential in various in vivo studies. This review aims to present an overview of 5-HT7 receptors and of the medicinal chemistry programs that led to the identification of new, potent and selective 5-HT7 receptors ligands. Structure-activity relationships studies based on molecular docking and pharmacophoric approaches are also described.

Secondary metabolites from lichen as potent inhibitors of advanced glycation end products and vasodilative agents.

Secondary metabolites from lichens are known for exhibiting various biological effects such as anti-inflammatory, antioxidant and antibacterial activities. Despite this wide range of reported biological effects, their impact on the formation of advanced glycation end products (AGEs) remains vastly unexplored. The latter are known contributors to lifestyle and age-related diseases such as Alzheimer and Parkinson. Moreover, the development of atherosclerosis and arterial stiffness is causally linked to the formation of AGEs. With this in mind, the present work evaluated the inhibitory effects of secondary lichen metabolites on the formation of pentosidine-like AGEs' by using an in vitro, Maillard reaction based, fluorescence assay. Overall, thirty-seven natural and five synthetically modified compounds were tested, eighteen of which exhibiting IC50 values in the range of 0.05 to 0.70 mM. This corresponds to 2 to 32 fold of the inhibitory activity of aminoguanidine. Targeting one major inhibiting mechanism of AGEs formation, all compounds were additionally evaluated on their radical scavenging capacities in an DPPH assay. Furthermore, as both AGEs' formation and hypertension are major risk factors for atherosclerosis, compounds that were available in sufficient amounts were also tested for their vasodilative effects. Overall, and though some of the active compounds were previously reported cytotoxic, present results highlight the interesting potential of secondary lichen metabolites as anti-AGEs and vasodilative agents.