In the second study, the researchers demonstrated that curcumin diminished the activating effect of oxidized LDL on stellate cells by suppressing LOX-1 gene expression, again via
PPAR-gamma activation. Conversely, pre-treating the cells with a
PPAR-gamma antagonist (PD68235) eliminated the inhibitory effect of curcumin.
Finally, the investigators showed that by increasing oxidative stress, insulin stimulates hepatic stellate cell proliferation and collagen production.