Jerusalem Balsam Contains Mastic

The sticky resins, such as frankincense, myrrh, and mastic that exude from certain types of evergreen trees have long been used as medicines called balsams (from a word of ancient Semitic origin). Balsams are fragrant because of the aromatic oils and acids they contain, and they have also been widely used as incense and perfume. Although they can be found worldwide, their recorded history begins in the Near East, where they have been used medicinally for thousands of years.
Not all balsams are of ancient origin, however. One of the most commercially successful formulations was developed in the early eighteenth century by a Franciscan monk, Antonio Menzani di Cuna, who lived in the monastery of the order of Saint Savior in Jerusalem. He was a physician and pharmacist, and in his day the Franciscan pharmacy in Jerusalem was regarded as among the finest in the Christian world.
The Jerusalem Balsam was used as a kind of panacea, being administered both topically for all kinds of skin disorders, as well as the healing of wounds and bruises, and internally for such conditions as stomachache, worms, hemorrhoids, headaches, dizziness, ear and teeth problems, blood spitting, and even heart disease.
A multidisciplinary team of scholars from Israel (their research) recently recreated the four-ingredient formulation (from an Italian-language manuscript found in the monastery archive) so they could test it for medicinal properties. Here are the ingredients, including the botanical names as we now know them:

•Olibanum* (Boswellia species) – 6 oz
•Mastic (Pistacia lentiscus) – 4 oz
•Aloe (Aloe species, probably vera) – 3 oz
•Myrrh (Commiphora species) – 1 oz

These ingredients were macerated in 6 lb of alcohol distilled from wine, and the extract was used as a medicine for the kinds of ailments mentioned above.
The Israeli scientists duplicated the formula using specimens from the plant species most likely to have been used originally. In laboratory and animal experiments, they found that this Jerusalem Balsam exhibited significant anti-inflammatory, antibacterial, and antioxidative actions. 
Thus, modern science has confirmed the medicinal value of a remedy that was popular as a panacea throughout Europe and the Near East for about two centuries. Unfortunately, however, it’s impossible to say which ingredient is responsible for which effect. In the authors’ words,
Is the activity of the mixture due to a single chemical entity or to synergism of compounds from different plant species? Or is it an ‘entourage effect,’ … in which nonactive constituents enhance the activity of an active constituent?