A missense mutation in the sodium channel ß2 subunit reveals SCN2B as a new candidate gene for Brugada syndrome.

Brugada Syndrome (BrS) is a familial disease associated with sudden cardiac death. A 20%-25% of BrS patients carry genetic defects that cause loss-of-function of the voltage-gated cardiac sodium channel. Thus, 70%-75% of patients remain without a genetic diagnosis. In this work, we identified a novel missense mutation (p.Asp211Gly) in the sodium ß2 subunit encoded by SCN2B, in a woman diagnosed with BrS. We studied the sodium current (INa ) from cells coexpressing Nav 1.5 and wild-type (ß2WT) or mutant (ß2D211G) ß2 subunits. Our electrophysiological analysis showed a 39.4% reduction in INa density when Nav 1.5 was coexpressed with the ß2D211G. Single channel analysis showed that the mutation did not affect the Nav 1.5 unitary channel conductance. Instead, protein membrane detection experiments suggested that ß2D211G decreases Nav 1.5 cell surface expression. The effect of the mutant ß2 subunit on the INa strongly suggests that SCN2B is a new candidate gene associated with BrS.

Bioactive Phytochemicals from Mercurialis spp. Used in Traditional Spanish Medicine.

Plants from the genus Mercurialis have a long history of use as herbal remedies in traditional Spanish medicine. The growing interest in the conservation of knowledge related to biodiversity has encouraged us to review the bioactive phytochemicals from the four most widespread Mercurialis species in the Iberian Peninsula (M. annua L., M. ambigua L., M. perennis L., and M. tomentosa L.). First, the medicinal uses of these four species throughout Spain were compiled, and then a bibliographical search on their chemical composition was conducted in an attempt to justify their reported traditional uses. We found that most of the medicinal uses of Mercurialis spp. are supported by scientific evidence. This includes its antidiabetic and antihypertensive properties attributable to the flavonoid rutin and narcissin, respectively; its benefits in the treatment of skin dark spots, attributable to mequinol; and its anti-inflammatory activity, attributable to scopoletin, kaempferol, squalene, and cycloartenol. This review contributes to the validation of the medicinal uses of Mercurialis spp. in Spain and provides some new avenues for further investigations on the biological activity of this interesting medicinal plant.