- Mastic is the resin of Pistacia lentiscus, a shrub of the sumac family (Anacardiaceae) found in the Mediterranean regions of France, Spain, Portugal, Greece, Turkey, and Africa. Mastic is sometimes referred to as "arabic gum," which is not to be confused with "gum arabic," a different substance consisting of hardened sap from the acacia tree (Acacia senegal, Acacia seyal). Other plant parts of Pistacia lentiscus, such as the leaf, may contain compounds not present in the resin.
- Pistacia lentiscus has been traditionally used to treat high blood pressure and upset stomach. It has also been used for ulcers and may have antibacterial activity against the bacteria that plays a role in some ulcers (Helicobacter pylori). Further trials are needed to confirm the antiulcer activity of Pistacia lentiscus and to establish any benefit that it may have over other conventional treatments for ulcer. There is currently insufficient high-quality scientific evidence in support of Pistacia lentiscus for other uses, such as other gastrointestinal disorders and dental plaque.