The regulation in key protein expression related to circadian rhythms with a natural compound containing rosemary and hemerocallis fulva extract in vitro

Abstract

Increasing evidence suggests that the core clock proteins of the circadian system play important roles in prevention, development, and/or progression of various pathologies, such as obesity, diabetes and sleep disorders. In this study, we investigated if the natural compound, CLOCK ® (mixture of rosemary and hemerocallis fulva extract) regulates the key protein expression related circadian rhythms in rat C6 glioma cells, using immunefluorescence and Western blotting analysis. The CLOCK complex incubation significantly enhanced Clock (circadian locomotor output cycles kaput), Bmal1 (brain and muscle Arnt‐like protein 1), Sirt (Sirtuin 1), F‐box and leucine‐rich repeat protein 21 (Fbxl21) and Fbxl3 expression in a dose‐dependent manner, compared to the control cells. CLOCK also stimulates the protein levels of brain‐derived neurotrophic factor (BDNF), which is a member of the neurotrophin family of growth factors. Oxidative stress can induce the dysregulated circadian rhythms. We also tested if CLOCK attenuates the damage of these core proteins expression in oxygen‐glucose deprivation (OGD) treated L6 muscle cells. OGD treatment significantly reduced 2‐NBDG uptake as measured by fluorescent microcopy and down‐regulated Clock, Bmal1 and Sirt1 protein levels in L6 muscle cells. CLOCK complex attenuated the damages‐induced by OGD on glucose uptake and the expression of these core proteins. These results indicate that the natural compound, CLOCK® may be beneficial on improving the dysfunction of circadian rhythms and likely circadian related diseases.Support or Funding InformationIn‐ingredients.com Funding