Andrographolide Modulate some Toll-like Receptors and Cytokines Expressions in HL-60 Cell Line

Andrographolide, a labdane diterpenoid, is quantitatively the major bioactive secondary metabolite of Andrographis paniculata, which is now considered to be a promising therapeutic lead for prevention and cure of inflammatory disorders. Although involvements of Toll-like receptors (TLR) and diverse cytokines have been implicated in its modes of actions, as yet no reports on its effects on expressions of TLRs have appeared. Observations reported in this communication reveal that a non-cytotoxic concentration of andrographolide (10 µM) completely suppresses TLR-7 and TLR-8 expressions in HL-60 cells and has no effects on TLR-3 expressions in the cell line. Observed effects of this concentration of andrographolide on the expressions of three quantified cytokines (TNF-α, IL-1β and IL-10) in HL-60 cells were not as pronounced as its suppressing effects on the two TLR expressions. These observations indicate that modulation of TLR-7 and TLR-8 mediated inflammatory and anti-inflammatory cytokines expression are involved in the modes of actions of andrographolide.