Delivery of Apoptosis-inducing Piperine to Triple-negative Breast Cancer Cells via Co-polymeric Nanoparticles.

BACKGROUND/AIM: Piperine, a major alkaloid of the fruit of black pepper plants, selectively inhibits the growth of triple-negative breast cancer cells but its lipophilicity restricts possible clinical application. This study therefore determined the feasibility of encapsulating piperine in nanoparticles (NPs) to increase its solubility in an aqueous environment. MATERIALS AND METHODS: Piperine-loaded biodegradable methoxy poly(ethylene glycol)-poly(lactic-co-glycolic) acid copolymer-based NPs were produced by single emulsion solvent extraction and thin-film hydration. Growth and viability of triple-negative breast cancer (TNBC) cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin-V-FLUOS/propidium iodide staining, respectively. RESULTS: Thin-film hydration was superior to single emulsion solvent extraction, yielding piperine-loaded NPs with an average size of 50 nm. Piperine-loaded NPs inhibited TNBC cell growth and induced apoptosis while sparing normal fibroblasts. CONCLUSION: It is feasible to deliver a cytotoxic concentration of piperine to TNBC cells via NPs with the potential for improved bioavailability and solubility in biological fluids.

PepSAVI-MS reveals anticancer and antifungal cycloviolacins in Viola odorata.

Widespread resistance to antimicrobial and cancer therapeutics is evolving in every country worldwide and has a direct impact on global health, agriculture and the economy. The specificity and selectivity of bioactive peptide natural products present a possible stopgap measure to address the ongoing deficit of new therapeutic compounds. PepSAVI-MS (Statistically-guided bioActive Peptides prioritized VIa Mass Spectrometry) is an adaptable method for the analysis of natural product libraries to rapidly identify bioactive peptides. This pipeline was validated via screening of the cyclotide-rich botanical species Viola odorata and identification of the known antimicrobial and anticancer cyclotide cycloviolacin O2. Herein we present and validate novel bioactivities of the anthelmintic V. odorata cyclotide, cycloviolacin O8 (cyO8), including micromolar anticancer activity against PC-3 prostate, MDA-MB-231 breast, and OVCAR-3 ovarian cancer cell lines and antifungal activity against the agricultural pathogen Fusarium graminearum. A reduction/alkylation strategy in tandem with PepSAVI-MS analysis also revealed several previously uncharacterized putatively bioactive cyclotides. Downstream implementation of ultraviolet photodissociation (UVPD) tandem mass spectrometry is demonstrated for cyO8 as a method to address traditionally difficult-to-sequence cyclotide species. This work emphasizes the therapeutic and agricultural potential of natural product bioactive peptides and the necessity of developing robust analytical tools to deconvolute nature's complexity.