When scientists add a stress signal to blood vessel cells in a dish, those cells start making a sticky protein that can cause inflammation—but two natural plant compounds, luteolin and apigenin, stop this from happening, especially at higher doses.

When cells lining blood vessels get stirred up by a protein called TNF-alpha (which happens during inflammation), two natural plant compounds—luteolin and apigenin—can calm them down by blocking a key internal signal (NF-kappa B) that tells the cells to stick to immune cells. This might help reduce swelling and inflammation.

When scientists add certain plant compounds called luteolin and apigenin to blood vessel cells that are stirred up by an inflammation signal, fewer immune cells stick to them—kind of like stopping sticky notes from clinging. Other similar plant compounds usually don’t help, except for quercetin, which helps a little.

A natural compound called PD 098063 can block a specific signal that makes blood vessel cells stick to immune cells—this might help reduce inflammation—without messing with other similar signals.