The extracts of Lobaria pindarensis, an edible lichen from Himalayas, suppress inflammatory response and fibrillation of amyloid β-protein in cultured microglial cells: Active depsidones, norstictic acid and stictic acid, are responsible for the functions

Lobaria pindarensis Räsänen is an edible and medicinal lichen found in the Himalayas that has been used as ethnomedicine for years to combat inflammation. The study aimed to evaluate the ability of L. pindarensis extracts and its main depsidones to suppress inflammation and Aβ fibril formation in cultured cells induced by LPS or Aβ42. The mRNA and protein expressions of inflammatory cytokines were declined significantly by the applied herbal extracts and depsidones in the LPS/Aβ-treated immune cells (p < 0.05 to p < 0.001). In addition, the extracts and depsidones of L. pindarensis showed enhancement of phagocytotic function of microglia and disassembling aggregated Aβ fibrils in dose-dependent manners (p < 0.05 to p < 0.001). The study presents the first evidence that L. pindarensis extracts have the potential to suppress inflammation and Aβ fibril protein aggregation, making it a promising candidate for developing health food supplements for Alzheimer's patients.