Disruption in circadian rhythm affects the production of inflammatory cytokines. Understanding how it behaves in diseased conditions is essential. Despite the role of the interleukin-1β (IL-1β), a potent inflammatory cytokine, in human diseases, little is known about the steady-state circadian rhythm of IL-1β in healthy individuals. This short study investigates the diurnal pattern of salivary IL-1β throughout the day in healthy young adults. Twelve participants provided saliva samples at various times throughout the day. Salivary IL-1β were assessed using enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Salivary IL-1β levels were highest at 0430 h and lowest at 0000 h and shared a similar diurnal pattern to that of salivary IL-6. Western blot analysis showed that these levels correspond to the mature form of IL-1β. Our findings are important as it established the diurnal pattern of salivary IL-1β is fluctuating normally throughout the day. The findings also open an incredible opportunity for developing research conducted in the field with saliva as the diagnostic tool.
Keywords: healthy; interleukin-1β; interleukin-6; saliva; young adult.