Natural Substances, Probiotics, and Synthetic Agents in the Treatment and Prevention of Honeybee Nosemosis.

Honeybees are important pollinators, but they are continuously exposed to a variety of fungal and bacterial diseases. One of the various diseases affecting honeybees is nosemosis caused by microsporidia from the Nosema genus. Honeybees are mainly infected through consumption of infected food or faeces containing Nosema spp. spores. Nosemosis causes damage to the middle intestine epithelium, which leads to food absorption disorders and honeybee malnutrition. Fumagillin, i.e., the antibiotic used to treat nosemosis, was withdrawn in 2016 from EU countries. Therefore, researchers have been looking for compounds of both natural and synthetic origin to fight nosemosis. Such compounds should not have a negative impact on bees but is expected to inhibit the disease. Natural compounds tested against nosemosis include, e.g., essential oils (EOs), plant extracts, propolis, and bacterial metabolites, while synthetic substances tested as anti-nosemosis agents are represented by porphyrins, vitamins, antibiotics, phenolic, ascorbic acids, and others. This publication presents an 18-year overview of various studies of a number of natural and synthetic compounds used in the treatment and prevention of nosemosis cited in PubMed, GoogleScholar, and CrossRef.

The associations among the breeding performance of Osmia bicornis L. (Hymenoptera: Megachilidae), burden of pathogens and nest parasites along urbanisation gradient.

Urban environments may negatively affect the development of organisms. In host-pathogen/parasite systems, this impact may lead to increased manifestations of pathogens that decrease the success of their hosts in urban environments compared to rural ones. We tested this hypothesis in the solitary bee Osmia bicornis L. We estimated the development of bees, their reproductive success and the manifestation of different pathogens and nest parasites along an urbanisation gradient. We conducted the experiment in an urbanisation gradient in sites representing three environments: urban, suburban and rural. First, we analysed the manifestation of bacterial and fungal microorganisms in pollen loads, within dried/mummified individuals, on the surface of cocoons and on the surface of diapausing adult individuals by using the MALDI-TOF MS technique. We also verified genetic samples from diapausing individuals for the presence of the parasitic Nosema apis (Zandler, 1909) and N. ceranae (Fries et al., 1996) species. Finally, we assessed the level of reproductive success and manifestations of brood parasites. Not any biological material from the nests was infected by pathogenic microorganisms. This result indicates that the nests are not a reservoir of the pathogenic bacteria and that O. bicornis offspring are not a source or vectors of these pathogens to the surrounding environment and indirectly to other bee species. In urban sites, there was a lower number of parasites than in suburban and rural environments. The presence of parasites was negatively correlated with the reproductive success and may be a limiting factor for O. bicornis populations. We also found that urban sites had the highest indices of reproductive success and the lowest number of breeding failures compared to suburban and rural sites. Moreover, bacterial and fungal transmission is not a serious threat in the studied region.

Evaluation of Anthelmintic Activity and Composition of Pumpkin (Cucurbita pepo L.) Seed Extracts-In Vitro and in Vivo Studies.

UNLABELLED: A significant number of studies report growing resistance in nematodes thriving in both humans and livestock. This study was conducted to evaluate the in vitro and in vivo anthelmintic efficiency of Curcubita pepo (C. pepo) L. hot water extract (HWE), cold water extract (CWE) or ethanol extract (ETE) on two model nematodes: Caenorhabditis elegans (C. elegans) and Heligmosoides bakeri (H. bakeri). METHODS: Raman, IR and LC-MS spectroscopy analyses were performed on the studied plant material to deliver qualitative and quantitative data on the composition of the obtained extracts: ETE, HWE and CWE. The in vitro activity evaluation showed an impact of C. pepo extracts on C. elegans and different developmental stages of H. bakeri. The following in vivo experiments on mice infected with H. bakeri confirmed inhibitory properties of the most active pumpkin extract selected by the in vitro study. All of the extracts were found to contain cucurbitine, aminoacids, fatty acids, and-for the first time-berberine and palmatine were identified. All C. pepo seed extracts exhibited a nematidicidal potential in vitro, affecting the survival of L1 and L2 H. bakeri larvae. The ETE was the strongest and demonstrated a positive effect on H. bakeri eggs hatching and marked inhibitory properties against worm motility, compared to a PBS control. No significant effects of pumpkin seed extracts on C. elegans integrity or motility were found. The EtOH extract in the in vivo studies showed anthelmintic properties against both H. bakeri fecal egg counts and adult worm burdens. The highest egg counts reduction was observed for the 8 g/kg dose (IC50 against H. bakeri = 2.43; 95% Cl = 2.01-2.94). A decrease in faecal egg counts (FEC) was accompanied by a significant reduction in worm burden of the treated mice compared to the control group. CONCLUSIONS: Pumpkin seed extracts may be used to control of Gastrointestinal (G.I.) nematode infections. This relatively inexpensive alternative to the currently available chemotherapeutic should be considered as a novel drug candidate in the nearest future.

Coenzyme Q10 treatments influence the lifespan and key biochemical resistance systems in the honeybee, Apis mellifera.

Natural bioactive preparations that will boost apian resistance, aid body detoxification, or fight crucial bee diseases are in demand. Therefore, we examined the influence of coenzyme Q10 (CoQ10, 2,3-dimethoxy, 5-methyl, 6-decaprenyl benzoquinone) treatment on honeybee lifespan, Nosema resistance, the activity/concentration of antioxidants, proteases and protease inhibitors, and biomarkers. CoQ10 slows age-related metabolic processes. Workers that consumed CoQ10 lived longer than untreated controls and were less infested with Nosema spp. Relative to controls, the CoQ10-treated workers had higher protein concentrations that increased with age but then they decreased in older bees. CoQ10 treatments increased the activities of antioxidant enzymes (superoxide dismutase, GPx, catalase, glutathione S-transferase), protease inhibitors, biomarkers (aspartate aminotransferase, alkaline phosphatase, alanine aminotransferase), the total antioxidant potential level, and concentrations of uric acid and creatinine. The activities of acidic, neutral, and alkaline proteases, and concentrations of albumin and urea were lower in the bees that were administered CoQ10. CoQ10 could be taken into consideration as a natural diet supplement in early spring before pollen sources become available in the temperate Central European climate. A response to CoQ10 administration that is similar to mammals supports our view that Apis mellifera is a model organism for biochemical gerontology.