Bioaccessibility and bioavailability of Moringa oleifera seed flour polyphenols

Abstract

The defatted Moringa oleifera seed flour (DMSF) that is left over after extraction of moringa oil is rich in protein and polyphenols, these polyphenols were evaluated for bio-accessibility and bio-availability. Bio-accessibility of DMSF polyphenols was evaluated by in vitro gastric simulation model using amylase, porcine pepsin, pancreatin enzymes and bile salts. After digestion, polyphenols were extracted from the samples using ethyl acetate and subjected to HPLC. Bio-availability of polyphenols was evaluated in vivo in male Wistar rats; the rats were orally administered with lyophilized DMSF bound phenolic extract at different time intervals and the tissues (blood, brain and liver) were collected post necropsy, processed, treated with enzyme mix to release conjugates and quantified though HPLC. In vitro bioaccessibility of DMSF polyphenols results revealed that bound phenolic were more accessible when compared to free phenolic. Further, in vivo bioavailability study showed high concentration of catechin in plasma (34 μg/100 μL) and liver (54 mg/100 mg of tissue) compared to other polyphenols followed by epicatechin and gallic acid. The Tmax and AUC of catechin in plasma was 2 h and 321.95 ± 11.2, respectively. The bioavailability studies will serve as basis to further investigate the health beneficial properties of DMSF polyphenols on targeted tissues.