TNF and acute liver failure: Changing the permeability of BBB by proinflammatory cytokines such as TNF and IL-1β in the liver causes the indiscriminate entry of toxins such as ammonia and xenobiotics, which produce a proinflammatory response.278 For example, BBB is destroyed in mice with acute liver failure, causes TNF and IL-1β to cross the BBB, and further impairs brain function.279