TY - JOUR

T1 - Pomegranate (Punica granatum L.) extract and Its anthocyanin and copigment fractions

T2 - Free radical scavenging activity and influence on cellular oxidative stress

AU - Kostka, Tina

AU - Ostberg-Potthoff, Johanna Josefine

AU - Briviba, Karlis

AU - Matsugo, Seiichi

AU - Winterhalter, Peter

AU - Esatbeyoglu, Tuba

N1 - Funding Information: Funding: The publication of this article was funded by the Open Access Fund of Leibniz Universität Hannover.

PY - 2020/11/6

Y1 - 2020/11/6

N2 - Secondary plant metabolites, e.g., polyphenols, are widely known as health-improving compounds that occur in natural functional foods such as pomegranates. While extracts generated from these fruits inhibit oxidative stress, the allocation of these effects to the different subgroups of substances, e.g., anthocyanins, "copigments" (polyphenols without anthocyanins), or polymeric compounds, is still unknown. Therefore, in the present study, polyphenols from pomegranate juice were extracted and separated into an anthocyanin and copigment fraction using adsorptive membrane chromatography. Phenolic compounds were determined by high performance liquid chromatography with photodiode array (HPLC-PDA) detection and HPLC-PDA electrospray ionization tandem mass spectrometry (HPLC-PDA-ESI-MS/MS), while the free radical scavenging activity of the pomegranate XAD‑7 extract and its fractions was evaluated by the Trolox equivalent antioxidant capacity (TEAC) assay and electron spin resonance (ESR) spectroscopy. Compared to juice, the total phenolic content and free radical scavenging potential was significantly higher in the pomegranate XAD-7 extract and its fractions. In comparison to the anthocyanin and copigment fraction, pomegranate XAD-7 extract showed the highest radical scavenging activity against galvinoxyl and DPPH radicals. Moreover, the enriched XAD-7 extract and its fractions were able to protect human hepatocellular HepG2 cells against oxidative stress induced by hydrogen peroxide. Overall, these results indicated that anthocyanins and copigments act together in reducing oxidative stress.

AB - Secondary plant metabolites, e.g., polyphenols, are widely known as health-improving compounds that occur in natural functional foods such as pomegranates. While extracts generated from these fruits inhibit oxidative stress, the allocation of these effects to the different subgroups of substances, e.g., anthocyanins, "copigments" (polyphenols without anthocyanins), or polymeric compounds, is still unknown. Therefore, in the present study, polyphenols from pomegranate juice were extracted and separated into an anthocyanin and copigment fraction using adsorptive membrane chromatography. Phenolic compounds were determined by high performance liquid chromatography with photodiode array (HPLC-PDA) detection and HPLC-PDA electrospray ionization tandem mass spectrometry (HPLC-PDA-ESI-MS/MS), while the free radical scavenging activity of the pomegranate XAD‑7 extract and its fractions was evaluated by the Trolox equivalent antioxidant capacity (TEAC) assay and electron spin resonance (ESR) spectroscopy. Compared to juice, the total phenolic content and free radical scavenging potential was significantly higher in the pomegranate XAD-7 extract and its fractions. In comparison to the anthocyanin and copigment fraction, pomegranate XAD-7 extract showed the highest radical scavenging activity against galvinoxyl and DPPH radicals. Moreover, the enriched XAD-7 extract and its fractions were able to protect human hepatocellular HepG2 cells against oxidative stress induced by hydrogen peroxide. Overall, these results indicated that anthocyanins and copigments act together in reducing oxidative stress.

KW - Adsorptive membrane chromatography

KW - Antioxidant

KW - Cell culture

KW - Electron spin resonance spectroscopy

KW - HepG2

KW - HPLC

KW - Pomegranate

UR - http://www.scopus.com/inward/record.url?scp=85109360272&partnerID=8YFLogxK

U2 - 10.3390/foods9111617

DO - 10.3390/foods9111617

M3 - Article

C2 - 33172172

VL - 9

JO - Foods

JF - Foods

IS - 11

M1 - 1617

ER -