Placental Passage of Protopine in an Ex Vivo Human Perfusion System

Safety assessment of the SGLT2 inhibitors empagliflozin, dapagliflozin and canagliflozin during pregnancy: An ex vivo human placenta perfusion and in vitro study

Although uncontrolled hyperglycaemia during pregnancy can cause complications for both the mother and her offspring, pharmacological treatment options for gestational and type 2 diabetes in pregnancy are still limited. Empagliflozin (EMPA), dapagliflozin (DAPA) and canagliflozin (CANA) are three sodium glucose co-transporter 2 (SGLT2) inhibitors, a newer group of oral antidiabetics that are well established in the treatment of type 2 diabetes mellitus in non-pregnant patients. To date, no data regarding their placental transfer and safety in pregnant women are available. We performed ex vivo human placental perfusions (n = 4, term placentas, creatinine and antipyrine as connectivity controls) to evaluate the transplacental transfer of EMPA, DAPA and CANA across the placental barrier and assessed their influence on the secretion of two placental peptide hormones, leptin and β-human chorionic gonadotropin (β-hCG). We discovered that all three SGLT2 inhibitors cross the placental barrier and attained maximal foetal to maternal concentration ratios of 0.38 ± 0.09 (EMPA), 0.67 ± 0.05 (DAPA) and 0.62 ± 0.05 (CANA) within the tested 360 min. A moderate but statistically significant decrease in placental leptin - but not β-hCG - secretion was observed during perfusions with SGLT2 inhibitors, which was confirmed in experiments performed with human placental BeWo cells. SGLT2 inhibitors are able to cross the human placental barrier and seem to interfere with placental leptin production. These observations should be considered in the ongoing discussion on the optimal treatment for gestational diabetes and type 2 diabetes mellitus in pregnancy.

Alkaloids in commercial preparations of California poppy - Quantification, intestinal permeability and microbiota interactions

California poppy products are commonly used for the treatment of nervousness, anxiety and sleeping disorders. Pharmacologically relevant constituents include the main alkaloids californidine, escholtzine and protopine. However, only limited information is available about the alkaloid content in commercial preparations and their intestinal absorption. Moreover, a possible metabolization of these alkaloids by the gut microbiota, and their impact on microbial activity and viability have not been investigated. Californidine, escholtzine and protopine were quantified by UHPLC-MS/MS in eight commercial California poppy products. The intestinal permeability of alkaloids was studied in Caco-2 cell as a model for absorption in the small intestine. The gut microbial biotransformation was explored in artificial gut microbiota from the in vitro PolyFermS model. In addition, the impact of these alkaloids and a California poppy extract on the microbial production of short-chain fatty acids (SCFAs) and the viability of microbiota was investigated. Contents of californidine, escholtzine and protopine in California poppy products were in the ranges of 0.13-2.55, 0.05-0.63 and 0.008-0.200 mg/g, respectively. In the Caco-2 cell model, californidine was low-to-moderately permeable while escholtzine and protopine were highly permeable. An active transport process was potentially involved in the transfer of the three alkaloids. The three compounds were not metabolized by the artificial gut microbiota over 24 h. Neither the California poppy extract nor the alkaloids markedly impacted microbial SCFA production and bacterial viability.

Simultaneous LC-MS/MS quantification of SGLT2 inhibitors and antipyrine in medium and tissue from human ex vivo placenta perfusions

A liquid chromatography - tandem mass spectrometry (LC-MS/MS) method has been developed to simultaneously measure four sodium glucose co-transporter 2 (SGLT2) inhibitors and the transfer marker antipyrine (ANTI) in perfusion medium and placental tissue collected from ex vivo human placental perfusions. The four SGLT2 inhibitors were empagliflozin (EMPA), dapagliflozin (DAPA), ertugliflozin (ERTU) and canagliflozin (CANA). Chromatographic separation was achieved on an Uptisphere® C18 reversed phase column (50 mm × 4.6 mm × 5 µm) within 2.85 min, using a gradient elution with 10 mM ammonium formate in water (mobile phase A) and acetonitrile (mobile phase B) both with 0.1% formic acid. Analysis of ammonium adduct ions was performed on an AB SCIEX 6500+ triple quadrupole mass spectrometer using positive electrospray ionisation and scheduled multiple reaction monitoring (sMRM). The transitions were m/z 468.00 → 355.20 (EMPA), m/z 426.00 → 167.20 (DAPA), m/z 437.10 → 206.90 (ERTU), m/z 462.00 → 249.00 (CANA) and m/z 189.20 → 55.90 (ANTI). The method was validated according to the European Medicines Agency guidelines and was proven to be selective, linear within a concentration range of 1-1000 µg/L (DAPA, CANA, ANTI) and 1-500 µg/L (EMPA, ERTU), accurate, precise and free of carry-over, instabilities, recovery and matrix effect issues. This newly developed method is suitable to analyse perfusion medium and placenta tissue samples collected during ex vivo human placenta perfusions. It thereby enables quantification of transport across the placental barrier of the SGLT2 inhibitors EMPA, DAPA, ERTU and CANA as well as the transfer marker ANTI.

Transplacental passage of hyperforin, hypericin, and valerenic acid

Safe medications for mild mental diseases in pregnancy are needed. Phytomedicines from St. John’s wort and valerian are valid candidates, but safety data in pregnancy are lacking. The transplacental transport of hyperforin and hypericin (from St. John’s wort), and valerenic acid (from valerian) was evaluated using the ex vivo cotyledon perfusion model (4 h perfusions, term placentae) and, in part, the in vitro Transwell assay with BeWo b30 cells. Antipyrine was used for comparison in both models. U(H)PLC-MS/MS bioanalytical methods were developed to quantify the compounds. Perfusion data obtained with term placentae showed that only minor amounts of hyperforin passed into the fetal circuit, while hypericin did not cross the placental barrier and valerenic acid equilibrated between the maternal and fetal compartments. None of the investigated compounds affected metabolic, functional, and histopathological parameters of the placenta during the perfusion experiments. Data from the Transwell model suggested that valerenic acid does not cross the placental cell layer. Taken together, our data suggest that throughout the pregnancy the potential fetal exposure to hypericin and hyperforin – but not to valerenic acid – is likely to be minimal.

Acute, chronic, and genotoxic studies on the protopine total alkaloids of the Macleaya cordata (willd.) R. Br. in rodents

The protopine alkaloids are widely distributed within the opium poppy family and have a wide range of pharmacological effects. MPTA is a product of the protopine total alkaloids extracted from the Macleaya cordata (Willd.) R. Br. Previously, we reported good anti-inflammatory activity of MPTA as well as oral acute and sub-chronic toxicity studies in rats. In order to perform a systematic toxicological safety assessment of MPTA, oral acute toxicity, genotoxicity (bone marrow cell chromosome aberration test, sperm abnormality test, bone marrow cell micronucleus test, and rat teratogenicity test), and chronic toxicity in mice were performed in this study. In the oral acute toxicity test, the LD₅₀ in ICR mice was 481.99 mg/kg, with 95% confidence limits ranging from 404.27 to 574.70 mg/kg. All three mutagenicity tests tested negative in the range of 60.25–241.00 mg/kg. The results of the teratogenicity test in rats showed no reproductive or embryonic developmental toxicity at only 7.53 mg/kg, which can be considered as a no observed effect level (NOEL) for the teratogenicity test. Therefore, MPTA is safe for use at the doses tested, but attention should be paid to the potential risk to pregnant animals and the safety evaluation and toxicity mechanisms in target animals should be further investigated.