Giampieri 2017 MiPschool Obergurgl
Event: MiPschool Obergurgl 2017
Oxidative stress is defined as a persistent imbalance between the production of highly reactive molecules (e.g. reactive oxygen species (ROS)) and antioxidant defenses. When the production of ROS/RNS exceeds the capacity of antioxidant defenses, oxidative stress may have a damaging effect on the functional and structural integrity of biological tissues, leading to many chronic diseases and ageing process. Exogenous antioxidants from the diet play an important beneficial role in improving endogenous antioxidant defenses of the human body against the development of chronic diseases . The aim of the present study is to evaluate the in vitro protective effects of a polyphenol-rich strawberry extract (0.5 mg/ml for 24 h) against oxidative stress, using H2O2 (5 mM for 1 h) and AAPH (10 mM for 24 h) as stressors in human dermal fibroblasts (HuDe). These two types of oxidizing agent could mimic two different conditions of oxidative stress: (i) hydrogen peroxide (H2O2), an acute condition in which cells are subjected to high doses of free radicals in a single time, and (ii) AAPH, a chronic condition in which the action of radical species persists over time.
We evaluated the protective effects of strawberry extract on ROS concentration and lipid peroxidation. Finally, because mitochondria are the main source of reactive species, which are by-products of cell energy production, we also assessed the protective effects of strawberry extract on mitochondrial status and functionality, by measuring the oxygen consumption rate (OCR) through the XF-24 Extracellular Flux Analyzer. Control and treated cells were exposed sequentially to each of three modulators of oxidative phosphorylation (OXPHOS) (oligomycin, 2,4-DNP and rotenone).
Strawberry extract was able to decrease intracellular ROS production (P < 0.05) and the extent of lipid peroxidation (P < 0.05) induced by both H2O2- and AAPH-mediated oxidative damage. Regarding mitochondrial functionality, basal OCR, an indicator of mitochondrial functionality, was markedly affected in cells treated with H2O2 (Fig. 1) or with AAPH (Fig. 2), and it was markedly improved (P < 0.05) in cells pre-treated with strawberry, as well as in those subsequently treated with H2O2 or AAPH. Addition of oligomycin caused an inhibition of electron flow resulting in marked decreases of OCR. The 2,4-DNP increased the OCR to the maximal mitochondrial respiration that cells can reach. Finally, the addition of rotenone/antimycin arrested the electron flow through the mitochondrial respiratory complexes causing a marked decrease in oxygen consumption, as shown by the drop in OCR levels in all cells. The maximal mitochondrial respiratory capacity (MMRC) in cells was obtained calculating the mean of OCR values after injection of 2,4-DNP minus the mean of OCR values after oligomycin injection: treatment with H2O2 or AAPH caused a significant decrease (P < 0.05) in MMRC, while after pre-treatment with strawberries an improvement was found. Moreover, pre-treatment with strawberry extract, before oxidative damage with H2O2 or AAPH, restored the MMRC close to basal OCR values compared to cells treated only with H2O2 or AAPH (Fig. 5c), demonstrating the beneficial and protective effect of the extract on mitochondrial functionality.
In conclusion, our results report that strawberry extract was effective in decreasing intracellular ROS concentration and in protecting lipid, and mitochondrial functionality from the damage induced by free radicals, suggesting a protective effect on skin cells against damage induced by oxidative stress.
• Bioblast editor: Kandolf G
Labels: MiParea: Respiration, Exercise physiology;nutrition;life style, Pharmacology;toxicology
Coupling state: LEAK Pathway: ROX
Event: B1, Poster
- Giampieri F(1), Gasparrini M(1), Forbes-Hernandez TY(2), Afrin S(1), Cianciosi D(1), Reboredo-Rodriguez P(3), Varela-Lopez A(4), Maurizio Battino1
- Dept Scienze Cliniche Specialistiche ed Odontostomatologiche, Univ Politecnica delle Marche
- Area Nutrición y Salud, Univ Internacional Iberoamericana
- Dept Quimica Analıtica y Alimentaria, Univ Vigo
- Dept Physiol, Inst Nutrition Food Technol ‘‘José Mataix”, Univ Granada, Spain.- [email protected]
Figure 1. Evaluation of oxygen consumption rate and MMRC in control and in strawberry pre-treated fibroblasts, stressed with H2O2.
Figure 2. Evaluation of oxygen consumption rate and MMRC in control and in strawberry pre-treated fibroblasts, stressed with AAPH.
- Giampieri F, Alvarez-Suarez JM, Battino M (2014) Strawberry and human health: effects beyond antioxidant activity. J Agric Food Chem 62:3867-76.