Strawberry (Fragaria ananassa duch.) Alba extract attenuates DNA damage in lymphocytes of patients with Alzheimer's disease.

Increased levels of oxidative stress and oxidative DNA damage are common features in the pathology of Alzheimer's disease (AD) found in neurons and peripheral cells like peripheral blood lymphocytes (PBL). Natural products such as strawberry cultivar Alba are an important source of bioactive nutrients that could help in lowering both the oxidative stress and DNA damage levels. The objective was to estimate the effects of Alba extract on DNA damage in peripheral blood lymphocytes of sporadic AD (aged 60-84 years) patients, and healthy elderly (aged 69-83 years) and young (aged 21-30 years) individuals in in vitro conditions. Comet assay was used as a sensitive technique for the evaluation of PBL DNA damage levels. Reduction of basal DNA damage level in PBL was shown in the young group after the incubation with Alba extract ranging from 25 to 200 µg/ml, with 100 µg/ml being the most effective concentration. Selected Alba extract of 100 µg/ml was further used for PBL treatment of AD and healthy elderly age matched group, displaying potential to significantly attenuate DNA damage levels in both groups (p < .05). Alba extract displayed biological activity against oxidative DNA damage, suggesting that its functional ingredients may have beneficial health effects. PRACTICAL APPLICATIONS: The data obtained in this preliminary study displayed that strawberry Alba extract is efficient against DNA damage induced by endogenous and exogenous oxidative stress in peripheral blood lymphocytes of Alzheimer`s disease in vitro. An active area of future research of Alba cultivar should be to determine the trials in in vivo systems. Our findings also suggest that Alba cultivar's functional ingredients potentially may have beneficial health effects in AD.

Manuka honey attenuates oxidative damage induced by H2O2 in human whole blood in vitro.

Manuka honey has been widely researched regarding its biological properties, in particular its antimicrobial and antioxidant capacities. We tested the genotoxic and genoprotective properties of Manuka honey, ranging from 25-1000 µg/mL, by performing an in vitro comet assay after exposure to human whole blood. No genotoxic effect on whole blood cells was observed within the tested concentration range (p = 0.154). Then, the antigenotoxic potency of Manuka honey against oxidative DNA damage to whole blood cells was assessed. Prior to Manuka honey treatment a modest decrease of H2O2-induced DNA damage was detected in cells, with no statistical significance (p = 0.087). Post-treatment, Manuka honey displayed a stronger potential to attenuate damaged cells at all tested concentrations, with a statistical significant difference (p < 0.001), where concentrations of 25 and 100 µg/mL were most efficient. Manuka honey exhibited a marked potential to protect DNA of whole blood cells from oxidative damage induced by hydrogen peroxide in vitro.