Multielemental Analysis of Bee Pollen, Propolis, and Royal Jelly Collected in West-Central Poland.

Beehive products possess nutritional value and health-promoting properties and are recommended as so-called "superfoods". However, because of their natural origin, they may contain relevant elemental contaminants. Therefore, to assess the quality of bee products, we examined concentrations of a broad range of 24 selected elements in propolis, bee pollen, and royal jelly. The quantitative analyses were performed with inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. The results of our research indicate that bee products contain essential macronutrients (i.e., K, P, and S) and micronutrients (i.e., Zn and Fe) in concentrations depending on the products' type. However, the presence of toxic heavy metals makes it necessary to test the quality of bee products before using them as dietary supplements. Bearing in mind that bee products are highly heterogenous and, depending on the environmental factors, differ in their elemental content, it is necessary to develop standards regulating the acceptable levels of inorganic pollutants. Furthermore, since bees and their products are considered to be an effective biomonitoring tool, our results may reflect the environment's condition in west-central Poland, affecting the health and well-being of both humans and bees.

Influence of time of day on propofol pharmacokinetics and pharmacodynamics in rabbits.

This study evaluates the administration time-of-day effects on propofol pharmacokinetics and sedative response in rabbits. Nine rabbits were sedated with 5 mg/kg propofol at three local clock times: 10:00, 16:00, and 22:00 h. Each rabbit served as its own control by being given a single infusion at the three different times of day on three separate occasions. Ten arterial blood samples were collected during each clock-time experiment for propofol assay. A two-compartment model was used to describe propofol pharmacokinetics, and the pedal withdrawal reflex was used as the sedation pharmacodynamic response. The categorical data comprising the presence or absence of pedal withdrawal reflex was described by a logistic model. The typical volume of the central compartment equaled 7.67 L and depended on rabbit body weight. The elimination rate constant depended on drug administration time; it was lowest at 10:00 h, highest at 16:00 h, and intermediate at 22:00 h. Delay of the anesthetic effect, with respect to plasma concentrations, was described by the effect compartment, with the rate constant for the distribution to the effector compartment equal to 0.335 min(-1). Drug concentration had a large effect on the probability of anesthesia. The degree of anesthesia was largest at 10:00 h, lowest at 16:00 h, and intermediate at 22:00 h. In summary, both the pharmacokinetics and pharmacodynamics of propofol in rabbits depended on administration time. The developed population approach may be used to assess chronopharmacokinetics and chronopharmacodynamics of medications in animals and humans.