Vpliv timola na aktivnost encima acetilholinesteraza in prehranjevanje pri kranjski čebeli

Potočan, Klara (author), Glavan, Gordana (mentor), Jemec Kokalj, Anita (co-mentor)

V zadnjih nekaj letih prihaja do visoke umrljivosti čebeljih družin. Varoja (Varroa destructor) predstavlja največjo grožnjo v čebelarstvu. Za zatiranje te pršice čebelarji posegajo po različnih sintetičnih akaricidih. V zadnjem času pa so vse več v uporabi tudi naravni akaricidi. Med te spadajo eterična olja in njihove aktivne učinkovine, med katerimi je tudi timol. Namen magistrske naloge je bil preučiti vpliv timola na encim acetilholinesterazo (AChE). Spremljali smo tudi aktivnost antioksidativnih encimov glutation S-transferaze (GST). Naš glavni cilj je bil ugotoviti, ali je uporaba timola v akaricidne namene varna za čebele. Čebele smo kronično 7 dni izpostavili različnim koncentracijam timola (0 %, 0,05 %, 0,5 % in 1 %; mase v hrani čebel). Po koncu poskusa smo določili aktivnost AChE ter GST v glavi in oprsju čebel. Ugotovili smo, da nekatere koncentracije timola povzročijo povečanje aktivnosti AChE v glavi (0,5 in 1 %) ter povečanje aktivnosti GST (0,05, 0,5 in 1 %) v glavi in oprsju. Ugotovili smo tudi, da se tekom poskusa zmanjšuje stopnja prehranjevanja v vseh testnih skupinah vključno s kontrolo, zato zmanjšanja ne moremo pripisati učinku timola. Naša študija je pokazala, da najvišja testirana koncentracija (1 %) ni varna za čebele, saj povzroči smrtnost čebel. Pri nižjih koncentracijah so opazne spremembe v aktivnostih encimov povezanih s prenosom živčnega signala in detoksifikacijskimi procesi.

• Language: Slovenian
• Keywords: kranjska čebela, timol, AChE, GST, proteini, prehranjevanje
• Work type: Master's thesis/paper
• Organization: BF - Biotechnical Faculty
• Year: 2019
• PID: 20.500.12556/RUL-108170
• COBISS.SI-ID: 5332303
• Publication date in RUL: 20.06.2019

Secondary language

• Language: English
• Title: The impact of thymol on the acetylcholinesterase enzyme activity and food consumption of Carniolan honey bee

Abstract

In the recent years, a high mortality of bee colonies is reported (colony collapse disorder). Varroa mites (Varroa destructor) are one of the biggest threats in beekeeping. Beekeepers use a wide range of different synthetic acaricides to keep varroa mites under control. The use of natural acaricides is also increased. Among them the essential oils and their active components are known, including thymol. The aim of this master's thesis was to examine the effect of thymol on enzyme acetycholineesterase (AChE). The main goal was to determine, if the usage of thymol in acaricidal purposes is safe for bees. We were also monitoring the activity of antioxidant enzymes glutathione S-transferase (GST). The bees were chronically exposed for 7 days to different concentrations of thymol (0 %, 0,05 %, 0,5 % in 1 %; mass in the bee food). At the end of the experiment, we determined the activity of AChE and GST in the heads and thoraxes of bees. We found out that AChE activity in heads increased at 0,5 % in 1 % of thymol and GST activity in heads and thoraxes increased at all three tested concentrations (0,05, 0,5 in 1 %). We also found out that during the experiment, the feeding rate decreased, but also in control group therefore the decrease was not induced by thymol. Our study showed that the highest tested concentration (1 %) is not safe for bees, as it causes bee mortality. At lower concentrations, changes in the activities of enzymes associated with the transmission of the nervous system and detoxification processes were shown.

• Keywords: Carniolan honey bee, thymol, AChE, GST, proteins, feeding rate