2017, Verjee, Sheela, Kelber, Olaf, Kolb, Christiane, Abdel-Aziz, Heba, Butterweck, Veronika

Objectives The major aim of this study was to get a detailed understanding of the exposure and fate of hypericin in the Caco-2 cell system when combined with various flavonoids, mixtures of flavonoids or Hypericum perforatum extract matrix (STW3-VI). Methods The permeation characteristics of hypericin in the absence or presence of quercetin, quercitrin, isoquercitrin, hyperoside and rutin were tested. Hypericin (5 μm) was mixed with single flavonoids (20 μm) or with different flavonoid combinations (each flavonoid 4 or 10 μm, total flavonoid concentration: 20 μm). Further, the uptake of hypericin (5 μm) in the presence of H. perforatum extract matrix (7.25, 29 and 58 μg/ml) was studied. Key findings Following application of hypericin to the apical side of the monolayer, only negligible amounts of the compound were found in the basolateral compartment. From all tested flavonoids, only quercitrin increased the basolateral amount of hypericin. Dual flavonoid combinations were not superior compared to the single combinations. The amount of hypericin in the basolateral compartment increased concentration-dependently in the presence of extract matrix (from 0 to 7.5%). Conclusion Comparing the effects of various flavonoid mixtures vs the extract matrix, it can be concluded that, besides flavonoids, the extract seems to contain further compounds (e.g. phenolic acids or proanthocyanidins) which substantially improve the permeation characteristics of hypericin.

2016, Moreira da Silva, Rodrigo, Verjee, Sheela, De Gaitani, Cristiane Masetto, Moraes de Oliveira, Anderson Rodrigo, Pires Bueno, Paula Carolina, Cavalheiro, Alberto José, Peporine Lopes, Norberto, Butterweck, Veronika

The clerodane diterpene casearin X (1)​, isolated from the leaves of Casearia sylvestris, is a potential new drug candidate due to its potent in vitro cytotoxic activity. In this work, the intestinal absorption mechanism of 1 was evaluated using Caco-​2 cells with and without active carboxylesterases (CES)​. An LC-​MS method was developed and validated for the quantification of 1. The estn. of permeability coeffs. was possible only under CES-​inhibited conditions in which 1 is able to cross the Caco-​2 cell monolayer. The mechanism is probably by active transport, with no significant efflux, but with a high retention of the compd. inside the cells. The enzymic hydrolysis assay demonstrates the susceptibility of 1 to first-​pass metab. as substrate for specific CES expressed in human intestine.

2017, Verjee, Sheela, Garo, Eliane, Pelaez, Sarah, Fertig, Orlando, Hamburger, Matthias, Butterweck, Veronika

During saffron (Crocus sativus) spice production, large amounts of floral biowaste are generated. It was the aim of this study to develop a value-added product from saffron floral biowaste to be used as a natural cosmetic ingredient. HPLC-PDA-MS analysis of saffron flower extracts revealed the presence of flavonols with the highest amounts in the acetone extract. Kaempferol-3-O-sophoroside was identified as the main flavonoid in the acetone extract (saffron flower acetone extract). Saffron flower acetone extract and kaempferol-3-O-sophoroside were tested in HaCaT cells for potential effects on cell migration, proliferation, and for anti-inflammatory properties. Saffron flower acetone extract concentration dependently (50–200 µg/mL) augmented cell proliferation, as indicated by an increased BrdU-incorporation, while kaempferol-3-O-sophoroside (1–50 µM) had no effect. Furthermore, treatment of HaCaT cells with saffron flower acetone extract, but not with kaempferol-3-O-sophoroside, concentration-dependently increased vascular endothelial growth factor secretion (control 49.72 pg/mL vs. saffron flower acetone extract at 200 µg/mL 218.60 pg/mL). Cell migration was determined using time-lapse microscopy and a modification of the scratch-wound assay in which saffron flower acetone extract significantly improved wound closure compared to the untreated control. Overproduction of the proinflammatory cytokines interleukin-8 and interleukin-6 in HaCaT cells was induced by TNF-α. Kaempferol-3-O-sophoroside (10–50 µM), but not saffron flower acetone extract, inhibited TNF-α-induced IL-8 secretion. The effect was comparable to 10 µM hydrocortisone (positive control). Interestingly, saffron flower acetone extract further increased IL-6 levels in TNF-α-treated HaCaT cells in a concentration-dependent manner. In summary, the pronounced wound healing properties of saffron flower acetone extract present a promising application for the cosmetic industry.

2016, Jähne, Evelyn A., Eigenmann, Daniela E., Moradi-Afrapoli, Fahimeh, Verjee, Sheela, Butterweck, Veronika, Hebeisen, Simon, Hettich, Timm, Schlotterbeck, Götz, Smiesko, Martin, Hamburger, Matthias, Oufir, Mouhssin

Tryptanthrin and (E,​Z)​-​3-​(4-​hydroxy-​3,​5-​dimethoxybenzylidene)​indolinone (indolinone) were recently isolated from Isatis tinctoria as potent anti-​inflammatory and antiallergic alkaloids, and shown to inhibit COX-​2, 5-​LOX catalyzed leukotriene synthesis, and mast cell degranulation at low μM to nM concns. To assess their suitability for oral administration, we screened the compds. in an in vitro intestinal permeability assay using human colonic adenocarcinoma cells. For exact quantification of the compds., validated UPLC-​MS​/MS methods were used. Tryptanthrin displayed high permeability (apparent permeability coeff. > 32.0 × 10-​6 cm​/s) across the cell monolayer. The efflux ratio below 2 (< 1.12) and unchanged apparent permeability coeff. values in the presence of the P-​glycoprotein inhibitor verapamil (50 μM) indicated that tryptanthrin was not involved in P-​glycoprotein interactions. For indolinone, a low recovery was found in the human colon adenocarcinoma cell assay. High-​resoln. mass spectrometry pointed to extensive phase II metab. of indolinone (sulfation and glucuronidation)​. Possible cardiotoxic liability of the compds. was assessed in vitro by measurement of an inhibitory effect on human ether-​a-​go-​go-​related gene tail currents in stably transfected HEK 293 cells using the patch clamp technique. Low human ether-​a-​go-​go-​related gene inhibition was found for tryptanthrin (IC50 > 10 μM) and indolinone (IC50 of 24.96 μM)​. The anal. of compds. using various in silico methods confirmed favorable pharmacokinetic properties, as well as a slight inhibition of the human ether-​a-​go-​go-​related gene potassium channel at micromolar concns.

2016-07, Butterweck, Veronika, Verjee, Sheela, Abdel-Aziz, Heba, Kelber, Olaf

2015-08, Verjee, Sheela, Abdel-Aziz, Heba, Butterweck, Veronika, Brügger, Daniela