Determination and confirmation of methyl p-hydroxybenzoate in royal jelly and other foods produced by the honey bee

Placental transport of parabens studied using an ex-vivo human perfusion model

INTRODUCTION

Parabens are a group of chemicals widely used as preservatives in daily consumer products such as cosmetics, food items, pharmaceuticals and household commodities. They have been broadly detected in human samples indicating a general human exposure, and concerns arose from their potential endocrine disrupting effect. Especially the exposure to parabens during pregnancy is concerning, as the time of fetal development is a particularly vulnerable period. The aim of this study was to investigate the transport and metabolism of four commonly used parabens: methyl-, ethyl-, propyl- and butylparaben (MeP, EtP, PrP and BuP) and the metabolite para-hydroxybenzoic acid (PHBA) across the human placenta.

METHODS

An ex-vivo human placental perfusion model was used. The test compounds were added in the maternal compartment (with initial concentrations of 1 mM or 0.1 mM). Placental transport was evaluated by fetal-maternal concentration ratios (FM-ratio), transport index (TI) and indicative permeability (IP).

RESULTS

Information about parabens kinetics was taken from 10 perfusions and PHBA from 7 perfusions. Paraben metabolism was not detected. The placental transport of MeP, EtP, PrP, BuP and PHBA revealed a transfer from maternal to fetal circulations with FM₁₂₀ of 0.86 ± 0.27 (MeP), 0.98 ± 0.28 (EtP), 1.00 ± 0.28 (PrP), 1.12 ± 0.59 (BuP) and 0.82 ± 0.37 (PHBA). The test substances accumulated in the perfused tissue in some degree. The average kinetic parameters FM-ratio, TI and IP were not different between chemicals.

DISCUSSION

The present study shows that the placenta barrier is permeable to all four parabens and the metabolite, which implies potential fetal exposure.

Case report: haemorrhagic colitis associated with royal jelly intake

The case report of a 53-year-old woman with abdominal pain and bloody diarrhoea is described. Prior to the onset of symptoms the patient had taken royal jelly for 25 days. Colonoscopy revealed that the mucosa was haemorrhagic and oedematous throughout the 20 cm long sigmoid colon. Histopathologically, mucosal haemorrhage, oedema, and infiltration of inflammatory cells were observed. Transmission electron microscopic examination revealed platelet aggregation in 30% of capillaries in the mucosal lesions. The drug-induced lymphocyte stimulation test was slightly positive for royal jelly (847 c.p.m., SI = 147%) compared with the control (576 c.p.m.). The patient's signs and symptoms disappeared within a few days after the initiation of conservative therapy, and the colonic lesions disappeared after 2 weeks of this therapy. This is the first reported case of haemorrhagic colitis associated with royal jelly intake.