Immunomodulating activity of Aronia melanocarpa polyphenols.

Giang Ho,Rune Slimestad,Marie Bräunlich,Helle Wangensteen,Karl Malterud,Hilde Barsett,Ingvild Austarheim

doi:10.3390/ijms150711626

Abstract

The immunomodulating effects of isolated proanthocyanidin-rich fractions, procyanidins C1, B5 and B2 and anthocyanins of Aronia melanocarpa were investigated. In this work, the complement-modulating activities, the inhibitory activities on nitric oxide (NO) production in LPS-induced RAW 264.7 macrophages and effects on cell viability of these polyphenols were studied. Several of the proanthocyanidin-rich fractions, the procyanidins C1, B5 and B2 and the cyanidin aglycone possessed strong complement-fixing activities. Cyanidin 3-glucoside possessed stronger activity than the other anthocyanins. Procyanidins C1, B5 and B2 and proanthocyanidin-rich fractions having an average degree of polymerization (PD) of 7 and 34 showed inhibitory activities on NO production in LPS-stimulated RAW 264.7 mouse macrophages. All, except for the fraction containing proanthocyanidins with PD 34, showed inhibitory effects without affecting cell viability. This study suggests that polyphenolic compounds of A. melanocarpa may have beneficial effects as immunomodulators and anti-inflammatory agents.

Highlights

With recent advances in the understanding of how cells communicate with each other to signal effector functions, it has become possible to think of strategies to manipulate these signaling pathways in order to influence host responses
Aronia berries were extracted with dichloromethane, 96% EtOH and 50% EtOH as previously described [16]. 1H-NMR and 13C-NMR analyses revealed that proanthocyanidins were present in the
Thiolysis of the Sephadex fractions revealed an average degree of polymerization (DP) of 7 for Seph d and 34 for Seph g, indicating that the DP of proanthocyanidins found in the subfractions Seph d–g increases with the elution volume

Summary

Introduction

With recent advances in the understanding of how cells communicate with each other to signal effector functions, it has become possible to think of strategies to manipulate these signaling pathways in order to influence host responses. The complement system comprises a group of serum proteins and cell membrane receptors that function primarily to fight infections. It participates in processes such as lysis of foreign cells, inflammation and phagocytosis [4]. While some studies on the effect of anthocyanins, proanthocyanidins and extracts rich in these compounds have been published [10,11,12,13], the knowledge on aronia extract and pure substances from the plant in regard to effects on the human complement system and NO production in LPS-stimulated macrophages is scant [14,15]. In order to get a broader view of the activity of the fractions and substances, two different assays were chosen for this investigation

Fractionation and Chemical Characterization

Complement-Fixing Activity

Plant Material

Complement Fixing Assay

Conclusions