Antioxidant Capacity

The aim of the present study was to investigate the chemical composition of essential oils extracted from leaves of Eucalyptus globulus (E. globulus) plant, using gas-chromatography coupled with mass spectrometry (GC/MS) method, and to evaluate their antioxidant capacity by means of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), reducing power, and β-carotene/linoleic acid assays, as well as their antibacterial activity against the major Gram-negative periodontopathogenic (Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis) and Gram-positive cariogenic (Streptococcus mutans, Streptococcus sobrinus) bacterial species. The GC/MS analysis allowed the identification of 26 compounds with the predominance of oxygenated monoterpenes (78.58%); 1,8-Cineole (55.29%), Spathulenol (7.44%) and α- Terpineol (5.46%) being the main components. The tested oil exhibited a weak antioxidant capacity, but a marked antibacterial activity against Gram negative bacteria, more specifically F. nucleatum ATCC 25586 (MIC= 1.14 mg/mL) and P. gingivalis ATCC33277 (MIC= 0.28 mg/mL). Therefore, essential oils from E. globulus may have a potential therapeutic application for the treatment of periodontal diseases.

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Levels of phenolics, major catechins [(+)-catechin, (-)-epicatechin, procyanidin dimers B1, B2, B3, and B4], phenolic acids (gallic acid and caffeic acid), caftaric acid, malvidin-3-glucoside, peonidin-3-glucoside, and cyanidin-3-glucoside were quantified by HPLC with UV detection for 54 French varietal commercial wines taken from southern France to study the antioxidant capacity and the daily dietary intake of these compounds for the French population. The highest antioxidant capacity was obtained with red wines and ranged from 12.8 mmol/L (Grenache) to 25.2 mmol/L (Pinot Noir). For white wines, Chardonnay enriched in phenolics by special wine-making was found to have an antioxidant capacity of 13.8 mmol/L, comparable to red wine values. For red wines classified by vintages (1996-1999) antioxidant capacities were approximately 20 mmol/L and then decreased to 13.4 mmol/L for vintages 1995-1991. Sweet white wines have 1.7 times more antioxidant capacity (3.2 mmol/L) than dry white wines (1.91 mmol/L). On the basis of a still significant French wine consumption of 180 mL/day/person, the current daily intake of catechins (monomers and dimers B1, B2, B3, and B4) averaged 5 (dry white wine), 4.36 (sweet white wines), 7.70 (rosé wines), 31.98 (red wines), and 66.94 (dry white wine enriched in phenolic) mg/day/resident for the French population. Red wine, and particularly Pinot Noir, Egiodola, Syrah, Cabernet Sauvignon, and Merlot varieties, or Chardonnay enriched in phenolics during wine-making for white varieties contribute to a very significant catechin dietary intake.