Toxicity of mycotoxins to honeybees and its amelioration by propolis

Abstract

Honeybees (Apis mellifera) and their resource-rich nests are hosts to a wide range of saprophytic fungi, including species that produce mycotoxins. The toxicity of aflatoxin B1 (AB1) and ochratoxin A (OTA), products of Aspergillus species often found in honeybee hives, was evaluated and LC 50 values for both toxins were calculated. Workers can tolerate a wide range of concentrations of both OTA and AB1. At low concentrations, AB1 (1 µg/g and 2.5 µg/g diet) and OTA (1 µg/g) did not have any apparent toxic effects on bees. Enhancement of the toxicity of AB1 by piperonyl butoxide (PBO), a known inhibitor of cytochrome P450 monooxygenases, indicates a role for P450s in AB1 detoxification in honeybees. Extracts of propolis, a complex mixture of plant-derived chemicals, including many flavonoids and other phenolic compounds, similarly ameliorated aflatoxin toxicity and delayed the onset of mortality. Collectively, these results suggest that tolerance of AB1 by honeybees may be due to P450-mediated metabolic detoxification. Propolis may serve a hitherto unrecognized role in honey bee health by enhancing the activity of P450 enzymes involved in mycotoxin detoxification. honeybee / aflatoxin B1 / ochratoxin A / cytochrome P450 monooxygenases / piperonyl butoxide / propolis

Abscisic acid enhances the immune response in Apis mellifera and contributes to the colony fitness

“…In this sense, it has been found that resins collected by bees affect the expression of immunity genes (Simone et al 2009) and also that bees self-medicate by increasing resin collection in response to fungal infections (Simone-Finstrom and Spivak 2012). In another approach, Niu et al (2011) demonstrated that propolis extracts reduce toxicity of mycotoxins. All these pieces of work demonstrated that it is imperative to find alternative ways of pesticide usage and attenuate the emergence of resistant plagues (Maggi et al 2010b).…”

Effects of multiple Bt proteins and GNA lectin on in vitro-reared honey bee larvae

“…Feeding treatments of in vitro-reared honey bee larvae for Bt protein bioassays. toxicity, LD 50 values were calculated, taking into account the colony dependence of test individuals (Hendriksma et al, 2011a), with 95% confidence intervals determined by Fieller's method (Finney, 1971;Niu et al, 2011). The prepupae weight analysis was performed using linear models (lm: Chambers, 1992, Anova type III) to measure treatment, colony, gradient, and trial effects (Table IIB).…”

Polycyclic aromatic hydrocarbons and risk elements in honey from the South Moravian region (Czech Republic)

“…trace elements (Conti and Botre 2001), pesticides (Blasco et al 2003), antibiotic residues (Hammel et al 2008), and polycyclic aromatic hydrocarbons (PAHs) (Dobrinas et al 2008). On the other hand, honeybees use their own detoxification mechanisms to decrease the content of harmful substances (Ferreira et al 2010;Niu et al 2011). The PAHs belong to the family of persistent organic pollutants with properties negatively impacting the human organism such as carcinogenicity, mutagenicity, etc.…”