Matrix effects of the hydroethanolic extract and the butanol fraction of calyces from Physalis peruviana L. on the biopharmaceutics classification of rutin.

OBJECTIVES: The Biopharmaceutics Classification System (BCS) categorizes active pharmaceutical ingredients according to their solubility and permeability properties, which are susceptible to matrix or formulation effects. The aim of this research was to evaluate the matrix effects of a hydroethanolic extract of calyces from Physalis peruviana L. (HEE) and its butanol fraction (BF), on the biopharmaceutics classification of their major compound, quercetin-3-O-rutinoside (rutin, RU). METHODS: Rutin was quantified by HPLC-UV, and Caco-2 cell monolayer transport studies were performed to obtain the apparent permeability values (Papp ). Aqueous solubility was determined at pH 6.8 and 7.4. KEY FINDINGS: The Papp values followed this order: BF > HEE > RU (1.77 ± 0.02 > 1.53 ± 0.07 > 0.90 ± 0.03 × 10-5  cm/s). The lowest solubility values followed this order: HEE > RU > BF (2.988 ± 0.07 > 0.205 ± 0.002 > 0.189 ± 0.005 mg/ml). CONCLUSIONS: According to these results, rutin could be classified as BCS classes III (high solubility/low permeability) and IV (low solubility/low permeability), depending on the plant matrix. Further work needs to be done in order to establish how apply the BCS for research and development of new botanical drugs or for bioequivalence purposes.

Investigation of the cytotoxic activity of two novel digitoxigenin analogues on H460 lung cancer cells.

Cardiac glycosides (CGs) are natural compounds traditionally used for the treatment of heart disorders, and recently new therapeutic possibilities were proposed. Their antitumor reports and clinical trials have notably enhanced, including those targeted for lung cancer, the most lethal type that lacks of new treatment agents, instigating the research of these molecules. The CGs studied here, named C10 {3ß-[(N-(2-hydroxyethyl)aminoacetyl]amino-3-deoxydigitoxigenin} and C18 (3ß-(aminoacetyl)amino-3-deoxydigitoxigenin), are semisynthetic derivatives prepared from digitoxigenin scaffold. Both compounds demonstrated high cytotoxicity for different cancer cell lines, especially H460 lung cancer cells, and their cytotoxic effects were deeply investigated using different methodological approaches. C10 induced cell death at lower concentrations and during shorter periods of treatment than C18, and increased the number of small and irregular nuclei, which are characteristics of apoptosis. This type of cell death was confirmed by caspase-3/7 assay. Both compounds reduced H460 cells proliferative potential by long-term action, and C10 showed the strongest potential. Moreover, these compounds induced a significant decrease of the area and viability of H460 spheroids providing preclinical favorable profiles to develop new chemotherapeutic agents.

Development of Caco-2 cells-based gene reporter assays and evaluation of herb-drug interactions involving CYP3A4 and CYP2D6 gene expression.

The indiscriminate use of medicinal plants and herbal medicinal products concomitantly with conventional drugs may result in herb-drug interactions that may lead to fluctuations in drug bioavailability, therapeutic failure, and/or toxic effects. CYP450 enzymes play an important role in drug biotransformation and herb-drug interactions. Thus, the aim of this study was to develop and apply Caco-2 cells-based gene reporter assays to study in vitro the potential occurrence of CYP3A4 and CYP2D6 gene expression modulation by standardized extracts of selected medicinal plants. Reporter cell lines developed showed a significant increase in CYP3A4 and CYP2D6 reporter fluorescent emission, 4 and 16-fold respectively, when compared to the controls. The standardized extracts of Cecropia glaziovii, Bauhinia forficata and Echinacea sp. significantly increased CYP3A4 reporter fluorescence, and those of Ilex paraguariensis, Bauhinia forficata and Echinacea sp. significantly decreased CYP2D6 reporter fluorescence in Caco-2 cells-based gene reporter assays. The data obtained suggest that CYP3A4 and CYP2D6 gene expression seem to be modulated by the extracts tested. In addition, the reporter cell lines developed are functional assays that could be used to study drug-drug and herb-drug interactions during the research and development of new drugs.