Comparative Evaluation of Polyphenol Contents and Biological Activities of Five Cistus L. Species Native to Turkey

In this study phytochemical compounds and antioxidant capacity, cytotoxic, antimicrobial and anti-biofilm activities of hydroethanolic extracts of five Cistus species (C. creticus L., C. laurifolius L., C. monspeliensis L., C. parviflorus Lam. and C. salviifolius L.) distributed in Turkey were investigated. (+)-catechin, epigallocatechin gallate, quercetin-3-O-rutinoside, quercetin-3-O-glucoside, kaempferol-3-O-glucoside, luteolin were detected in different amounts. Strongest antioxidant capacities were observed with C. creticus, and C. parvifolius (0.476 and 0.452, respectively). Minimum inhibitory concentrations (MIC) of the extracts were determined between 32 and 128 μg/mL against different bacteria and Candida strains. C. monspeliensis and C. laurifolius extracts were inhibited the biofilm production levels of three Gram-negative bacteria (E. coli, S. enterica, P. aeruginosa), two Gram-positive bacteria (S. aureus, B. subtilis) and three Candida strains (C. albicans, C. parapsilosis, C. krusei). C. creticus extract showed strongest cytotoxic activity against human breast adenocarcinoma (MCF-7) and prostate cell lines (PC-3) (IC₅₀ : 14.04±2.78 μg/mL and 34.04±2.74 μg/mL, respectively) among all plants tested.