Human immunodeficiency virus type 1 (HIV-1) is a cytopathic retrovirus and the primary etiological agent of
acquired immunodeficiency syndrome (
AIDS) and related disorders. In cells chronically infected with HIV-1,
nuclear factor-kappaB (
NF-kappaB) activation by external stimuli such as
tumor necrosis factor alpha (
TNFalpha) augments replication of HIV-1.
NF-kappaB involves in many diseases such as
inflammation,
cancer, and
Crohn's disease. In this paper, we exhibit that (i) HIV-1gene expression was inhibited by
lignin, (ii) fraction of small molecular mass in HBS
lignin (less than 0.5kDa) had stronger inhibitory effects than large molecular mass (more than 1.3kDa), (iii)
lignin also inhibited activation of
NF-kappaB induced by
TNFalpha, (iv) among six
lignin dimer-like compounds, compound 6 containing beta-5 bond has more potent inhibitory activity than compounds 1, 2, 3, 4 and 5, which contain beta-1, beta-O-4, 5-5, or beta-beta structural units. These results suggested that small molecules of
lignin inhibit HIV-1 replication through suppression of HIV-1 transcription from LTR including activation via
NF-kappaB. Low molecular
lignin may be a beneficial material or
drug leads as a new class for
AIDS and
NF-kappaB-related diseases.