Honokiol protects skin cells against inflammation, collagenolysis, apoptosis, and senescence caused by cigarette smoke damage.

Background: Pollution, especially cigarette smoke, is a major cause of skin damage.

Objectives: To assess the effects of the small molecule polyphenol, honokiol, on reversing cigarette smoke-induced damage in vitro to relevant skin cells.

Methods: Keratinocytes (HaCat) cultures were exposed to cigarette smoke and, after 48 hours, IL-1α and IL-8 were measured in cell supernatants.