Folk medicines in Kızılcıhamam has not been investigated in detail so far. Thus, this study aimed to conduct a comprehensive investigation of folk medicine in the Kızılcahamam district. Nine scientific field trips were organized to Kızılcahamam between April 2007 and July 2008. Data were obtained by field interviews with local people using open and semi-structured questionnaires. Results were evaluated statistically with the “use-value”, “informant consensus factor” and cultural importance index. Sixty-five species (69 taxa) that belong to 58 genera of 31 families were determined to be used as folk medicines. To the best of our knowledge, this is the first study to record four of these species as folk medicines. Plants from Compositae, Lamiaceae and Rosaceae families were used most frequently as folk medicines in Kızılcahamam. Plants in the study area are mainly used for gastrointestinal system problems, respiratory disorders, and urinary tract diseases. Residents from 41% of the villages where the scientific trips were carried out, declared that they are not using or interested in folk medicines. This study highlights once again the gradual reduction of folk medicinal knowledge and the urgent need for folk medicine investigations in all parts of Turkey.

Sideritis caesarea H. Duman, Aytaç & Başer of the family Lamiaceae is an endemic plant with different ethnobotanical uses in Anatolia. In this present study, the antioxidant and biological activity potential of different S caesarea extracts and purified compounds were evaluated in vitro using DPPH•, CUPRAC, and ABTS• methods. In addition, their urease and chymotrypsin enzyme inhibitory activities, antimicrobial potential, and total phenol and flavonoid contents were determined. The experimental results showed that the two isolated flavonoids {4′- O-methylhypolaetin-7- O-[6″′- O-acetyl- β-D-allopyranosyl-(1→2)]-6″- O-acetyl- β-D-glucopyranoside, and isoscutellarein-7- O-[6″′- O-acetyl- β-D-allopyranosyl-(1→2)]-6″- O-acetyl- β-D-glucopyranoside}, as well as their fractions, except the n-hexane and water residue, showed remarkable antioxidant activity. Interestingly, the ethyl acetate and water residue fractions inhibited the urease enzyme activity by 49.6% and 49.1%, respectively; while the n-hexane and dichloromethane fractions attracted attention with their relative high chymotrypsin inhibitory activity of 85.8%, and 82.4%, respectively. When evaluated for their in vitro antimicrobial potential, including Helicobacter pylori, only Bacillus subtilis was susceptible to the n-butanol fraction at 1 mg/mL, while all of the studied samples showed activity against the human pathogenic yeast Candida albicans with the range of 0.25 to 1 mg/mL minimum inhibitory concentrations. The initial antioxidant activity, enzyme inhibitions, and antimicrobial results of S caesarea extracts and compounds suggest the further potential for in vivo evaluations.