Is Hypericum perforatum agonist or antagonist of TRPC6 in neurons?

Abstract

Transient receptor potential canonical 6 (TRPC6) channel is a family of transient receptor superfamily. Hyperforin is an active component of Hypericum species including Hypericum perforatum (HPer). In the review paper, the author summarizes the recent information between TRPC6-induced Ca2+ entry, HPer and hyperforin to understand the etiology of the neurological diseases and potential therapeutic strategies. The TRPC6 in several cell types is activated by 2-Aminoethoxydiphenylborane (2-APB), 4,5 triphosphate (IP3) and diacylglycerol (DAG) pathways, although it was inhibited in the cells by several non-specific antagonists including gadolinium and lanthanum. Results of limited studies indicated that hyperforin caused intracellular Ca2+ elevations through TRPC6 activation in neurons and cells, although the intracellular Ca2+ elevation results were not confirmed by many recent studies. Release Ca2+ from internal stores instead of extracellular Ca2+ entry through activation of TRPC6 channel in neurons of brain was also reported. The TRPC6-induced Ca2+ influx was inhibited in brain by active components of some antioxidants. In conclusion, the present literature information shows that interaction between TRPC6-induced Ca2+ entry and hyperforin in neurons and cell lines are too complex and it has not been clarified yet