• bee products safety
• nutrition
• phytochemicals

ABSTRACT

Some phytochemicals may play a role in honey bee immune defense and their resistance to various diseases. Some phytochemicals are known to exhibit action in immune system or antimicrobial action. They may serve as a consumer-friendly alternative to antibiotics used in apiculture as in Europe the use of antibiotics is currently banned. Previous research showed that sanguinarine might be this alternative and several steps have been done to investigate its action in larvae and to formulate a product containing this compound. This thesis aims to (i) develop a method for determination of sanguinarine in sugar cake (ii) evaluate the alkaloids content in one pre-market commercial product which is designed to be administered to honey bees and (iii) evaluate the effect of sanguinarine on honey bee larvae development.
A reverse-phase HPLC method was developed for analysis of sanguinarine in samples and 23 samples were analyzed showing sanguinarine content in range of 180–326 (mg/kg) and chelerythrine in a range of 65–123 (mg/kg). The variability of is due to differences in the manufacturing process and storage conditions.
Honey bee larvae were reared under laboratory conditions by a previously published method. Two groups of larvae were administered food with two different concentrations of M. cordata extract (0.1% and 0.01% w/v) rich in sanguinarine and chelerythrine in approximate ratio of 3:1. The larval mortality was asessed at day 2,4 and 6 prior the defecation. At day 6 (last day of feeding) results show that sanguinarine in both concentrations significantly decreased larval viability. While untreated control had 75% survival rate, the tested extract resulted in decline of survival to 26% at 0.01% concentration and further to 4% with 0.1% concentration.
Although antimicrobial activity of sanguinarine has been reported previously by us, it is not yet clear whether this can be tolerated well by the bee larvae and thus have a positive effect as antibiotic replacer and immune booster. However, our results are in contrast with previous finding of the CULS Prague team (as in other previous experiment sanguinarine increased survival of both diseased and normal larvae). However, this has been done by a different rearing method and thus, this needs to be further investigated.