Antioksidativna, antiproliferativna i antimikrobna aktivnost odabranih ekstrakata tropova bobičastog voća

Abstract

U ovom radu su ispitani hemijski sastav, antioksidativna, antihiperglikemijska, antiproliferativna i antimikrobna aktivnost liofiliziranih metanolnih ekstrakata tropa maline (Rubusidaeus L) sorti Meeker (ETMM) i Willamette (ETMW), kupine (RubusfruticosusL) sorti Čačanska bestrna (ETKČ) i Thornfree (ETKT) i divlje borovnice (Vacciniummyrtillus L) (ETB). Sadržaj ukupnih polifenola (TPh), flavonoida (TF) i antocijana (TAc) u ekstraktima tropova određeni su spektrofotometrijskim metodama. Identifikacija i kvantifikacija fenolnih jedinjenja (fenolnihkiselina, flavonola i cijanidina) i vitamina C u ekstraktima tropova izvedena je HPLC analizom. Spektrofotometrijskim testovima određena je antioksidativna aktivnostna DPPH i ABTS+ radikale i redukciona sposobnost ekstrakata. ESR spektroskopijom utvrđen je uticaj ekstrakata na reaktivne hidroksil i superoksid anjon radikale. Antihiperglikemijska aktivnost ekstrakata određena je testom inhibicije α-glukozidaze. Antiproliferativna aktivnost ekstrakata tropova ispitana je in vitro, njihovim delovanjem na rast četiri histološki različite humane ćelije: HeLa (epitelni karcinom cerviksa), MCF7 (adenokarcinom dojke), HT-29 (adenokarcinom debelog creva) i MRC-5 (humani fetalni fibroblasti pluća). Antimikrobna aktivnost ekstrakata tropova bobičastog voća ispitana je na odabrane sojeve Gram-pozitivnih i Gram-negativnih bakterija, kvasaca i plesni disk difuzionom metodom i metodom „bunarčića”. Ispitana je i mogućnost primene liofiliziranih ekstrakata tropova bobičastog voća kao funkcionalnog dodatka sokovima od voća. Laboratorijski proizvedenim obogaćenim sokovima je određen sadržaj TPh, TF i TAc i utvrđena antioksidativna aktivnost testom redukcione sposobnosti i DPPH testom. Rezultati ispitivanja hemijskog sastava, antioksidativne, antihiperglikemijske, antiproliferativne i antimikrobne aktivnosti ETMM, ETMW, ETKČ, ETKT i ETB ukazuju da su svi ispitivani ekstrakti tropova potencijalni izvor prirodnih bioaktivnih jedinjenja, a antioksidativna aktivnost obogaćenih sokova ukazuje na mogućnost korišćenja ovih ekstrakata, kao funkcionalnih aditiva u proizvodnji različitih visoko vrednih prehrambenih proizvoda.

This work examined the chemical composition, the antioxidant, antihyperglycaemic, antiproliferative and antimicrobial activity of the freeze-dried raspberry (Rubus idaeus L.) varieties Meeker (ETMM) and Willamette (ETMW), blackberry (Rubus fruticosus L.) varieties (ETKČ) and Thornfree (ETKT), and wild blueberry (Vaccinium myrtillus L.) (ETB) pomaces methanol extracts. The content of total polyphenols (TPh), total flavonoids (TF) and total anthocyanins (TAc) in the pomace extracts were determined spectrophotometrically. Identification and quantification of the phenolic compounds (phenol acids, flavonols and cyanidins) and ascorbic acid in the pomace extracts was performed by HPLC analysis. The antioxidant activities of the extracts was determined spectrophotometrically using DPPH and ABTS+ free radicals and reducing ability assay. ESR spectroscopy is used for determination of pomace extracts’ influence on reactive hydroxyl and superoxide anion radicals. Antihyperglycaemic activity of the pomace extracts was determined using α-glucosidase inhibition assay. The antiproliferative activity of the pomace extracts was tested in vitro, testing their influence on the growth of four histologically different human tumor cells: HeLa (cervix epithelioid carcinoma), MCF7 (breast adenocarcinoma), HT-29 (colon adenocarcinoma) and MRC-5(human fetal lung fibroblasts). Antimicrobial activity of berry pomace extracts was tested on selected strains of Gram-positive and Gram-negative bacteria, yeasts and molds with the disc diffusion method and the method of “wells”. The possibility of freeze dried berry pomace extracts application as a fruit functional additive was investigated as well. Laboratory produced enriched juice was tested in terms of TPH, TF and TAc content, reducing ability and DPPH scavenging ability as well. The results of testing the chemical composition, the antioxidative, antihyperglycaemic, antiproliferative and antimicrobial activities of ETMM, ETMW, ETKČ, ETKT and ETB, indicate that all investigated pomace extracts are a potential source of natural bioactive compounds, and that the antioxidant activity enriched juice indicates the possibility of using these extracts, as a functional additive in the production of various high-value food products.