Objectives: To evaluate (1) the effect of a salivary substitute prepared using chamomile (Matricaria chamomilla L.) flower and flax (Linum usitatissimum L.) seed to relieve Primary burning mouth syndrome (BMS) symptoms, (2) their effect on the inhibition of matrix metallopeptidase 2 (MMP2) and MMP9 metalloproteinases, and (3) their potential cellular cytotoxic effect. Subjects: 40 women aging >40 years with diagnosis of primary BMS. Settings/Location: Center of Diagnosis of Diseases of the Mouth, Federal University of Pelotas, Brazil. Design: This was an open clinical trial where primary BMS patients used the homemade salivary. At the first appointment, after 30 and 60 days, the authors evaluated the pattern and intensity of BMS and xerostomia symptoms, and then determined and compared the unstimulated salivary flow rate (SFR), viscosity, and salivary pH. MMP2 and MMP9 activities in saliva and cytotoxicity were assessed using different concentrations of chamomile flower and flax seed separately. Interventions: Subjects used the homemade salivary substitute for 3 months and were instructed to rinse their mouth three to four times daily for 1 min. Outcome measures: A numeric rating scale to evaluate the intensity of burning sensation and xerostomia symptoms, salivary flow rate (SFR) to determine salivary volume, dynamic rheology technique for viscosity and a digital meter for salivary pH. MMP2 and MMP9 activities in saliva and cytotoxicity were assessed by zymography and cell viability assay respectively. Results: After treatment, severity of BMS symptoms decreased, the SFR increased, salivary viscosity decreased, and severity of xerostomia sensation (in patients who reported having this symptom) improved (p < 0.05). Chamomile flower and flax seed had no effect on inhibiting MMP2 and MMP9 activities, and neither showed cellular cytotoxic effects. Conclusion: This homemade salivary substitute is an economical, viable, easily manipulated, noncytotoxic, and a practical alternative to relieve BMS symptoms.
Keywords: burning mouth syndrome; cytotoxicity; matrix metalloproteinase 2; matrix metalloproteinase 9; viscosity; xerostomia.