Review Article

Nutritional and Phytochemical Composition and Associated Health Benefits of Oat (Avena sativa) Grains and Oat-Based Fermented Food Products

Table 8

Summary of in vivo and in vitro studies on the positive health outcomes of oat extracts and avenanthramides.

PlacePotential bioactive compounds/polyphenol extract of oatsStudy typeObserved health outcomesSources

CanadaAvenanthramide (AV-A, AV-B, and AV-C)-enriched oat extractsIn vivo: human blood samples were collected at 15, 30, and 45 min after drinking the test sample (oat beverage) and at 1, 2, 3, 5, and 10 hrs, and plasma GSH (glutathione or -glutamyl-cysteinyl-glycine tripeptide) status was assessedIncreasing plasma GSH (glutathione or -glutamyl-cysteinyl-glycine tripeptide) status and acting in synergy with other antioxidants such as vitamin E[119]
TurkeyOrganic solvent oat extractsIn vivo: test ointments (oat extracts) were applied topically to the wounded site of rats immediately after the wound was created with a surgical bladePossessing a wound healing effect[120]
CanadaOat groats flour extractIn vitro: cells were cultured at 37°C in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum, L-glutamine, and penicillin-streptomycin. Cells were then incubated for additional 24 hrs in a new medium containing varying concentrations of oat extracts. The inhibition of nuclear factor kappa beta (NF-kB) was measured using human 293T cells. A TransAM™ NF-kB ELISA kit was used to measure NF-kB binding activity to its consensus binding siteInhibition of NF-kB, indicating anti-inflammatory activity[13]
IndiaEthanol extract of oats flourIn vitro: Fenton’s reagent was made by combining ferric chloride, hydrogen peroxide, and ascorbic acid in a 1 : 1 : 1 ratio. Oat extract, Fenton’s reagent, DNA, and nuclease-free double-distilled water were used in the reaction. The protective effect of oat extracts was calculated using the retention percentage of normalized supercoiled DNADNA damage protection activity[121]
Avenanthramides (AV-1p, AV-1c, AV-1f, AV-1s, AV-2p, AV-2c, AV-2f, and AV-2s)In vitro: the comet assay (single-cell gel electrophoresis) was used to evaluate the test compounds’ potential protective effects against DNA damage in cells stressed with hydrogen peroxide. For 24 hrs, HT-29 cells (human colon adenocarcinoma cells) were incubated in a medium containing the test compoundsAntigenotoxic effects[122]
Avenanthramide (AV-2c)In vitro: human aortic smooth muscle cells (SMC) were cultured in the SMBM medium (Cambrex) containing 10% fetal bovine serum (FBS), and the cell culture was kept at 37°C in a humidified incubator supplied with a 95% air and 5% CO2 atmosphereInhibition of vascular smooth muscle cell proliferation[123]
Avenanthramides (isolated from oats)In vitro: normal human epidermal neonatal keratinocytes were maintained in the serum-free Epilife medium supplemented with 0.2% (v/v) bovine pituitary extract (BPE), 5 μg/mL bovine insulin, 0.18 μg/mL hydrocortisone, 5 μg/mL bovine transferrin, and 0.2 ng/mL human epidermal growth factorAnti-inflammatory and anti-itch activity[22]