Antioksidativno delovanje in inhibicija alfa-amilaze z ekstrakti bukovega ostrigarja (Pleurotus ostreatus)

Štravs, Ana (author), Pogačnik, Lea (mentor), Jamnik, Polona (co-mentor)

V okviru magistrskega dela smo določali antioksidativno učinkovitost (AOU) in inhibicijo α-amilaze z ekstrakti bukovega ostrigarja (Pleurotus ostreatus). Analizirali smo dva sveža vzorca različnega porekla (slovenski bukov ostrigar – SBO in madžarski bukov ostrigar – MBO) in dve prehranski dopolnili (prah slovenskega bukovega ostrigarja – SP in kitajske kapsule – KK). Pred pričetkom analiz smo preverili, kako na AOU ekstraktov vplivajo različni pogoji ekstrakcije in določili optimalni postopek ekstrakcije. Parametri, ki smo jih spreminjali, so bili: trajanje ekstrakcije (čas in stopnja), temperatura in uporaba različnih ekstrakcijskih topil. Ugotovili smo, da imajo različni pogoji ekstrakcije velik vpliv na AOU ekstraktov.AOU vzorcev smo določili na dva načina: z metodo lovljenja radikala DPPH• in v celicah kvasovke Saccharomyces cerevisiae. Z metodo DPPH• smo določili, da imajo etanolni ekstrakti višjo AOU kot vodni ekstrakti istih vzorcev. Največja razlika v AOU je vidna pri vzorcu iz prahu slovenskega bukovega ostrigarja (SBO), AOU vodnega ekstrakta SP je 1,46 mmol/g, AOU etanolnega ekstrakta SP pa 6,27 mmol/g. Pri preverjanju antioksidativnega delovanja ekstraktov v celicah smo ugotovili, da se je raven znotrajcelične oksidacije glede na kontrolo znižala pri kvasovkah, tretiranimi z etanolnimi ekstrakti SBO, MBO in KK in vodnima ekstraktoma MBO in KK, in sicer za 19,8-36,6 %. Ko primerjamo rezultate, dobljene na oba načina, je najbolj izrazita podobnost ta, da imajo etanolni ekstrakti višjo AOU, ne glede na izbrano metodo dela. Inhibicijo delovanja α-amilaze smo določali s pomočjo reagenta DNSA. Ugotovili smo, da vodni ekstrakti s koncentracijo 50 mg/mL encim α-amilazo inhibirajo boljše kot etanolni ekstrakti z enako koncentracijo. Pri primerjavi rezultatov, dobljenih pri analizi AOU in rezultatov inhibicije α-amilaze, nismo opazili povezave.

• Language: Slovenian
• Keywords: bukov ostrigar, Pleurotus ostreatus, antioksidanti, antioksidativna učinkovitost, DPPH•, protidiabetično delovanje, inhibicija α-amilaze
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [A. Štravs]
• Year: 2022
• PID: 20.500.12556/RUL-137596
• UDC: 577.1:635.8:547.9:66.094.3.097.8
• COBISS.SI-ID: 112480515
• Publication date in RUL: 23.06.2022

Secondary language

• Language: English
• Title: Antioxidative and antidiabetic activities of extracts from Pleurotus ostreatus

Abstract

Within the master's thesis, we determined antioxidant capacity (AOC) and α-amylase inhibition of oyster mushroom (Pleurotus ostreatus) extracts. We analyzed two fresh samples of different origin (Slovenian oyster mushroom – SBO and Hungarian oyster mushroom – MBO) and two dietary supplements (Slovenian oyster mushroom powder – SP and Chinese capsules – KK). First, we examined the impact of different extraction conditions on AOC and determined the optimal preparation of extracts.The parameters of extractions that we were observing were duration (time and stage), temperature, and use of different extraction solvents. We found that different extraction conditions have a great impact on the AOC of the extracts. AOC of the samples was determined by DPPH• assay and using yeast Saccharomyces cerevisiae. With the DPPH• assay, we determined that ethanol extracts have a higher AOC than aqueous extracts of the same samples. The most noticeable difference in AOC was found in the sample of Slovenian oyster mushroom powder (SP), AOC of aqueous extract of SP was 1.46 mmol/g, while AOC of ethanol extract of SP was 6.27 mmol/g. The intracellular oxidation test revealed that the values decreased, compared to the control samples when cells were treated with ethanol extracts SBO, MBO, and KK and water extracts MBO, and KK. They were lower by 19,8-36,6% when compared to the control samples. Inhibition of α-amylase activity was determined using the DNSA reagent. Aqueous extracts with a concentration of 50 mg / mL were found to inhibit the enzyme α-amylase better than ethanol extracts with the same concentration. No association was observed when comparing the results obtained in the AOC analysis and the results of α-amylase inhibition.

• Keywords: oyster mushroom, Pleurotus ostreatus, antioxidants, antioxidant capacity, DPPH•, antidiabetic activity, α-amylase inhibition