Polyprenylated Benzophenones from Brazilian Red Propolis: Analytical Characterization and Anticancer Activity.

The present work describes the extraction of a polyprenylated benzophenone-rich extract from Brazilian red propolis (ERPB), the development and validation of an RP-HPLC-UV method to characterize it, and its evaluation against breast cancer cell lines MCF-7 and MDA-MB-231, as well as the normal counterpart MCF-10 A. A mixture of gutifferone E and xanthochymol (1+2), and isolated oblongifolin B (3) were used as chemical standards for ERPB and were also evaluated. The concentrations of 1+2 and 3 corresponded to 16.68 % and 42.25 % of the total content of the extract, respectively, and the validation parameters evaluated were satisfactorily met. The cytotoxic effects of ERPB were assessed, and the obtained IC50 values were 19.58 µg/mL (MCF-10 A), 11.56 µg/mL (MCF-7), and 5.22 µg/mL (MDA-MB-231). In conclusion, ERPB exhibits promising cytotoxic effects on the tested breast cell lines. However, further investigation to elucidate its potential therapeutic applications and safety profile should be conducted.

Green and Red Brazilian Propolis: Antimicrobial Potential and Anti-Virulence against ATCC and Clinically Isolated Multidrug-Resistant Bacteria.

Brazilian green and red propolis stand out as commercial products for different medical applications. In this article, we report the antimicrobial activities of the hydroalcoholic extracts of green (EGP) and red (ERP) propolis, as well as guttiferone E plus xanthochymol (8) and oblongifolin B (9) from red propolis, against multidrug-resistant bacteria (MDRB). We undertook the minimal inhibitory (MIC) and bactericidal (MBC) concentrations, inhibition of biofilm formation (MICB50 ), catalase, coagulase, DNase, lipase, and hemolysin assays, along with molecular docking simulations. ERP was more effective by displaying MIC and MBC values <100 µg mL-1 . Compounds 8 and 9 displayed the lowest MIC values (0.98 to 31.25 µg mL-1 ) against all tested Gram-positive MDRB. They also inhibited the biofilm formation of S. aureus (ATCC 43300 and clinical isolate) and S. epidermidis (ATCC 14990 and clinical isolate), with MICB50 values between 1.56 and 6.25 µg mL-1 . The molecular docking results indicated that 8 and 9 might interact with the catalase's amino acids. Compounds 8 and 9 have great antimicrobial potential.