Nosema ceranae can cause major problems, such as immune suppression, gut epithelial cell degeneration, reduced honeybee lifespan, or suddenly colony collapse. As a novel approach in therapy, we hypothesize the stable gastric pentadecapeptide BPC 157 in honeybee therapy, to control N. ceranae invasions in apiary conditions: BPC 157 treated sugar syrup (0.25 L sugar syrup supplemented with 0.1 μg/ml BPC 157), as well as the pure sugar syrup (0.25 L sugar syrup; control), was administered to honeybee colonies in feeders situated under the roof of the hives, during 21 consecutive days, at the end of beekeeping season. The strength of honeybee colonies was increased 20 and 30 days after initial feeding with BPC 157 supplement (Day 1, 36.100 ± 698; Day 20, 64.860 ± 468; Day 30, 53.214 ± 312 estimated number of honeybees), in field conditions. The similar successful outcome occurs with the N. ceranae spore loads counted in the homogenates of sampled adult honeybees (Day 1, 6.286 ± 2.336; Day 20, 3.753 ± 1.835; Day 30, 2.005 ± 1.534 million spores/bee). Accordingly, with the noted increased strength of the colonies fed with sugar syrup supplemented with BPC 157, the number of N. ceranae spores per honeybee gradually decreased as well. Besides, honeybees infected with N. ceranae fed with sugar syrup exhibited severe damage of midgut wall layers and epithelial cells. By contrast, in honeybees infected with N. ceranae fed with sugar syrup supplemented with BPC 157, all damages were markedly attenuated, damages of the outer muscular coat, in particular. In conclusion, the results of the first field trial on diseased honeybee colonies with BPC 157 indicate significant therapeutic effects with the used oral therapy with BPC 157 supplementation.

ABSTRACT:Control of the nosema disease poses a major challenge, and therefore, treatment of this serious parasitic disease using natural preparations could be of great benefit. The aim of this study was to test the performance of zeolite clinoptilolite as a curative measure against honeybee colonies (Apis mellifera L.) naturally infected by Nosema ceranae. The histopathological structure, and the content and distribution of mucosubstances and histochemical activity of aminopeptidase and non-specific esterase in the midgut mucosa of honeybees originating from colonies fed sugar syrup supplemented with zeolite minerals was studied. A decline in the number of spores in honeybees fed with zeolite clinoliptolite was observed on the first sampling day (Day 10; 53.25 ± 15.15 million spores/bee), though a statistically lower number of spores in comparison to the control was confirmed on Day 20 (41.08 ± 9.4 million spores/bee), Day 30 (28.42 ± 7.79 million spores/bee) and Day 40 (24 ± 6.25 million spores/bee). The possibility of using natural zeolites as a dietary supplement for honeybee colonies as a preventative measure and for the reduction of the deleterious effects of nosemosis is discussed.

As a novel approach in therapy, we hypothesize the stable gastric pentadecapeptide BPC 157 in honeybee therapy, to control N. ceranae invasions in apiary conditions. Since its emergence as a novel pathogen of A. mellifera, N. ceranae has been generally associated with heavily diseased and moribund colonies (Vejsnæs et al., 2010). Nosema species primary parasites and replicates within epithelium of midgut and consequently impairs digestion and absorption of nutrients (Dussaubat et al., 2012). This tissue degeneration and prevention of gut epithelium renewal may explain early bee death. BPC 157 was originally an anti‐ulcer peptide used in trials for ulcerative colitis and now is in trials for the treatment of multiple sclerosis that largely interacts with NO‐system (Sikiric et al. 2014) and thought to be novel mediator of Robert's cytoprotection in rat studies, known to exert an immediate endothelium protection alongside with mucosal protection in stomach, known to counteract variously induced gastrointestinal lesions in various species, and thereby suited for the necessary generalization of the concept of the stomach cytoprotection to the entire gastrointestinal tract, as well as suited for generalization of the therapy affect to desirable counteraction in honeybee therapy of the effects of N. ceranae invasions in apiary conditions. Experimental group of honeybee colonies were additionally fed with 0.25L sugar syrup (1:1 water‐sugar; Viro šećer, Croatia) supplemented with 0.1μg/mL BPC 157, per day. Control group of honeybee colonies received only 0.25L sugar syrup prepared and provided in the same way. Treated sugar syrup, as well as the pure sugar syrup, was administered to honeybee colony in feeders situated under the roof of the hives, consecutively during 21 days (the field part of experiment was conducted during 30 consecutive days, beginning of July 21st, 2014). Along with markedly counteracted midgut lesions, a significant decline in the number of N. ceranae spores in honeybees fed with BPC 157 was observed on the end of experiment in comparison with first sampling day (Day 1: 62.86±23.36; Day 30: 20.05 ± 18.34 million spores/bee, respectively). Moreover, treated colonies have significantly more honeybees during second and third clinical inspection (estimation of number of bees in mid and late August) when is physiologically period of establishing long‐living winter honeybees. In conclusion, N. ceranae is considered to cause major health problems characterized by an immune suppression, a degeneration of gut epithelial cells and a reduction of bee lifespan. Thereby, the honeybee colonies fed with sugar syrup supplemented with BPC 157 over a short period, and markedly reduced number of spores compared to the initial spore count (average: 40.3% on 20th day and 68.1% on 30th day), could be promising for further therapy.Support or Funding InformationUniversity of Zagreb, Zagreb, Croatia (grant number BM099)