Antiproliferative and cytotoxic activity of extracts from Cistus incanus L. and Cistus monspeliensis L. on human prostate cell lines.

Benign prostatic hypertrophy (BPH) is a common condition in elderly men that impairs quality of life and leads to a number of medical complications. The use of phytotherapeutic compounds in patients with relatively moderate BPH symptoms has been growing steadily. In the present study, acute toxicity of lyophilised aqueous extracts of Cistus incanus L. and Cistus monspeliensis L., collected in Sicily, was evaluated on the shrimp (Artemia salina L.) lethality assay, an alternative test to determine the toxicity of natural products. The cytotoxic and growth inhibitory effects were studied on normal human prostate cells (PZ-HPV-7 and PNT1A) and on a lung fibroblast cell line (V79-4). Cell proliferation was evaluated by MTT and SRB assays. Cytotoxicity was measured using the Trypan blue exclusion assay. Cistus extract treatment on prostate cell lines resulted in an almost identical growth inhibitory response and in a significant decrease in an cell viability. These findings indicate the biologically relevant effect of polyphenolic compounds present in Cistus extracts, and suggest that these substances may prove beneficial in BPH treatment.

Simultaneous determination of catechins, rutin, and gallic acid in Cistus species extracts by HPLC with diode array detection.

A simple high-performance liquid chromatography method using a diode array detector (DAD) is developed for the simultaneous analysis of five major catechins: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GCT), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), and the phenolic plant metabolites gallic acid (GA) and rutin (RT) in lyophilized extracts of Cistus species. The optimal analytical conditions are investigated to obtain the best resolution and the highest UV sensitivity for the quantitative detection of catechins. The optimized conditions (acetonitrile-phosphate buffer 50 mM, pH 2.5, gradient elution system on a C18 reversed-phase column with a flow rate of 1 mL/min and UV absorbance at 210 nm) allowed a specific and repeatable separation of the studied analytes to be achieved. All compounds are successfully separated within 32 min. Calibration curves are linear in the 2-50 microg/mL range for GCT, C, and EGCG and in the 5-50 microg/mL range for GA, EGC, EC, and RT. The limit of detection values ranged from 0.24 to 0.74 microg/mL. The limit of quantitation limit values ranged from 0.77 to 1.94 microg/mL. The validated method is applied to the determination of the specific phytochemical markers GA, GCT, C, and RT in Cistus incanus and Cistus monspeliensis lyophilised extracts. The recovery values ranged between 78.7% and 98.2%. The described HPLC method appears suitable for the differentiation and determination of the most common catechins together with the glycoside rutin and the phenolic compound gallic acid and can be considered an effective and alternative procedure for the analyses of this important class of natural compounds.