(PO07-26-22) Novel ADM Ceylon Standardized Extract With Antioxidant and Antimicrobial Effects Evaluated in Caenorhabditis elegans Model

Objectives: The main objective is to develop a novel powdered extract from Ceylon tea, standardized to gallic acid, flavanols and xanthines, and to evaluate “in vivo” its functional properties.

Methods: Ceylon tea leaves and corresponding powdered extracts were obtained at laboratory and industrial scales. To analyze individual antioxidants, High Performance Liquid Chromatography (J. Chromatogr. A, 2000, 881, 439 – 447) and Gas Chromatography (ACS Food Sci. Technol., 2021, 1, 4, 596–604).

Oxidative stress resistance (J. Agric. Food Chem., 2011, 59, 2077–2085). C. elegans nematodes were egg-synchronized in NGM plates (control medium) and NGM plates containing Ceylon extract (0.1 to 2 mg/mL). Nematode viability was assessed after oxidative stress (2 mM H₂O₂). Vitamin C (10 µg/mL) was used as positive control. Experiments were carried out in duplicate.

Infection assays (Antioxidants 2021, 10, 536). Nematodes were age-synchronized by recovering the eggs from adults in agar plates, already seeded with E. coli OP50 (NGM), and NGM plates containing three different doses of Ceylon (0.1 to 1 mg/mL). The pathogen strain Staphylococcus aureus (ATCC25923) was used for infections. Nematodes were incubated at 25 ºC and scored for survival during 5–10 days.

Results: Chromatographic analyses

Industrial scale Ceylon extracts was standardized to gallic acid (1.8±0.0 %), monomeric, oligomeric flavanols and methyl xanthines, respectively 2.1±0.1 %, 0.2±0.0 %, & 4.2±0.1 %. The volatile composition showed characteristic profile of Camellia sinensis, with higher relative proportion of trans-2-hexenal (1.9±0.1 %), linalool (3.1±0.3 %) and benzaldehyde (3.5±0.2 %), together with limonene (12.0±1.3 %) and eugenol (13.0±0.0 %).

Antioxidant activity and pathogen protection

ADM® Ceylon extract showed significant protection both upon acute oxidative stress and S. aureus infection in the model of C. elegans. Thus, nematodes feeding 1 mg/mL of Ceylon extract, significantly increased their survival compared with control fed population (48% versus 28%). The extract (1 mg/mL) increased 20% survival vs control infected population.

Conclusions: ADM® Ceylon powdered extract is a novel standardized functional extract with potential antioxidant and protective effects against pathogens.

Funding Sources: Thanks to ADM® for funding this research work.