Inhibitory effects of compounds on LPS-induced TNF-a production
in human THP-1 cells. THP-1 cells were exposed to varying
concentrations of the compounds (1e100 mM) in a fresh serum-free
medium in both the presence and absence of LPS. TNF-a was
quantified by sandwich ELISA. As shown in Table 2, compounds 1e4
along with the positive control curcumin inhibited LPS-induced
TNF-a secretion in THP-1 cells in a dose-dependent manner. On
the other hand, their respective phenanthrene and dihydrophenanthrene
backbone were inactive.