Pistacia lentiscus is a dioecious evergreen shrub or small tree of the pistacio genus growing up to 4 m tall which is cultivated for its aromatic resin, mainly on the Greek island of Chios.
Pistacia lentiscus is native throughout the Mediterranean region, from Morocco and in the west through southern France and Turkey to Iraq and Iran in the east. Originally liquid, it is hardened, when the weather turns cold, into drops or patties of hard, brittle, translucent resin. When chewed, the resin softens and becomes a bright white gum.
Researches proved that mastic can reduce bacterial plaque in the mouth by 41.5%. A 1998 study by the University of Athens proved that mastic oil has antibacterial and antifungal properties. Another 1998 University of Nottingham study, claims that mastic can heal peptic ulcers by killing Helicobacter pylori, which causes peptic ulcers gastritis, and duodenitis. Some in vivo studies have shown that mastic gum has no significant effect on H. pylori when taken for a short periods of time. However, a recent and more extensive study showed that mastic gum reduced H. pylori populations after an insoluble and sticky polymer constituent of mastic gum was removed and taken for a longer period of time. Further analysis proved the acid fraction was the most active antibacterial extract, and the most active pure compound was isomasticadienolic acid.