RESUMO
Background: Herbal products regulated under different categories were found to be of different quality. This has been demonstrated by the increasing number of reports on the quality of herbal products in the scientific literature. Proper identification is an effective way to address this concerning issue early on in a products' manufacturing process. Objectives: To assess the quality of milk thistle, coneflower and black cohosh herbal drugs, preparations and products commercialized under different regulatory categories, and to illustrate the usefulness of HPTLC as a tool for evaluating quality. Methods: HPTLC methods were adapted from the European Pharmacopeia's monographs for milk thistle fruits, black cohosh and purple coneflower. Additional detection modes beyond those described in the monographs were employed, and the entire HPTLC fingerprints were used for examination of identity and purity of the investigated samples. Results: All products regulated as Traditional Herbal Medicinal Products were shown to be of high quality: their fingerprints were consistent and without unexpected zones. A significant number of food supplements show quality issues (mainly adulterations): 52.4% of milk thistle, 33.3% of coneflower, and 45.5% of black cohosh products. The same was observed in 66.6% of black cohosh herbal drugs and preparations.
RESUMO
PURPOSE: To measure the rosmarinic acid content of eight commercial tinctures derived from fresh (n= 5) and dried (n=3) Melissa officinalis herb. METHODS: Rosmarinic acid and the internal standard (esculin) were purchased from Aldrich Chemical Co. The column used was a Luna C18, 5 um (150 x 4.6 mm I.D., Phenomenex) maintained at ambient room temperature. The HPLC system consisted of a Shimadzu SCL-6B controller, Shimadzu LC-6A pumps, Shimadzu SPD-6A UV single wavelength spectrophotometric detector set to 320 nm and Shimadzu SIL-6B autosampler. Gradient elution of the samples and standard were performed using ammonium formate (0.02 M; pH 6.25 at 27 oC; eluent A) and methanol (eluent B). The gradient elution initial conditions were 2% of eluent B with linear gradient to 60% at 30 min, followed by linear gradient to 90% of eluent B at 31 min, this proportion being maintained for 4 min. The column was then returned to the initial condition at 36 min and maintained until the end of the run at 43 min. The flow rate was 1 mL/min. The assay was validated for sensitivity, accuracy and reproducibility. RESULTS: The content of rosmarinic acid in commercial tinctures was significantly higher in the tinctures made from dried plant material (2.96 - 22.18 mg/mL) compared to fresh plant tinctures (