It is generally accepted that dietary phenolics from fruits are of significant importance to human health. Unfortunately, there is minimal published data on how differences in phenolic structure(s) impact biological pathways at cellular and molecular levels. We observed that haskap berry extracts isolated with ethanol:formic acid:water or phenolic subclass fractions separated using different concentrations of ethanol (40% and 100%) impacted cell growth in a positive manner. All fractions and extracts significantly increased population doubling times. All extracts and fractions reduced intracellular free radicals; however, there were differences in these effects, indicating different abilities to scavenge free radicals. The extracts and fractions also exhibited differing impacts on transcripts encoding the antioxidant enzymes (CAT, SOD1, GPX1, GSS and HMOX1) and the phosphorylation state of nuclear factor-κB (NF-κB). We further observed that extracts and fractions containing different phenolic structures had divergent impacts on the mammalian target of rapamycin (mTOR) and sirtuin 1 (SIRT1). siRNA-mediated knockdown of SIRT1 transcripts demonstrated that this enzyme is key to eliciting haskap phenolic(s) impact on cells. We postulate that phenolic synergism is of significant importance when evaluating their dietary impact.

Phenolic extracts from five Saskatoon, Saskatchewan, bred and grown haskap berry varieties (Aurora, Blizzard, Honey Bee, Indigo Gem, and Tundra) were characterized via liquid chromatography with photodiode array detection (HPLC-PDA) and mass spectrometry (HPLC-MS/MS). Tundra had the highest phenolic content (727.0 mg/100 g FW) while Indigo Gem had the highest anthocyanin content (447.8 mg/100 g FW). HPLC-MS/MS identified two previously unreported anthocyanins (Tundra variety): delphinidin-sambubioside and a peonidin-pentoside. Fruit extracts were fractionated to produce an anthocyanin rich (40% ethanol) and flavanol/flavonol rich (100% ethanol) fraction. This process affords the ability to isolate/concentrate specific subclasses for nutraceutical applications. High in vitro radical scavenging was observed for all haskap phenolic extracts. An extract from the Tundra variety delayed borage oil oxidation more effectively than commercial antioxidants (BHT and Rosamox). These results show the high phenolic content of these haskaps along with their capacity for radical scavenging/delaying lipid oxidation, indicating potential commercial value.