Mastic is a resin, or gum, extracted from a tree grown in Mediterranean or Middle liastern regions. Long used as a chewing gum and a traditional medicine, mastic resin also has been developed for use in numerous industrial applications (Milovet al., 1998). Preliminary clinical evidence has confirmed that mastic resins are useful in the treatment of ulcers. Further, mastic has been shown to exhibit antibacterial activity against Helicobacter pylori, explaining its efficacy in ulcers. Mastic has also shown antibacterial, antiplaque, and autigirigival activity in the saliva and on the teeth (Takahashi et al., 2003).

Although mastic has not yet been well studied as an herbal medicine, preliminary clinical evidence is promising 10 confirm the efficacy of its historical use in treating ulcers (AI-Habbal, 1984; Huwez, 1986).

Al-Habbal et al. (1984) performed a double-blind, clinical study on mastic for treatment of duodenal ulcer. Twenty patients were given mastic (I g/day) and 18 received a placebo (lactose, 1 g/day) to for 2 weeks. Mastic treatment resulted in highly statistically significant improvements in both the symptomatic relief (80% of the treatment group versus 50% of the placebo group) and the clinical manifestation of disease as proven by endoscopic examination {70% of the treatment group versus 22% of the placebo patients). Additionally, mastic was found to be well tolerated with no side effects.

Antiplaque, Antigingival, and Antibacterial Activity of Mastic Chewing Gum
A chewing gum of mastic resin was tested in two double-blind, randomized, placebo-controlled studies for the control of dental plaque. In the first study, saliva was collected from the mouths of participants after mechanical brushing and chewing gum and examined for its antibacterial activity by mastic or placebo gum. The mastic chewing gum group showed statistically significant reductions in bacterial growth compared with the placebo group during the 4 hours of chewing gum. In the second study, mastic and placebo gum chewing (and no brushing) were tested over 7 days for their ability to control new plaque formation on tooth surfaces and on gingival inflammation. The mastic group showed significantly reduced plaque index measures and gingival index compared with the placebo group (Takahashi et al., 2003).

For treating ulcers and gastrointestinal discomfort, 1 g of mastic is used. Mastic is not known to produce any side effects and is thought to be safe (Al-Habbal et al., 1984).

Slippery elm contains mucilaginous compounds that are the reason why slipper}' is in its name and why it has herbal therapeutic uses. The mucilaginous effect of slippery elm has been used traditionally and safely for soothing irritated mucous membranes in the throat and sinuses during colds and sore throat, in the digestive system during digestive complaints (e.g., diarrhea, constipation, Crohn disease), and on the skin during minor irritations (e.g., poison oak and wound healing).

Although slippery elm lacks clinical support, the soothing effect of the mucilaginous components is well known. Additionally, related elm species have shown evidence of antimicrobial activity and promise for inflammation and diseases of the mucous membranes (Jun et al., 1998; Song et al., 2003; Ye el al., 1990; Youn et al., 2003).