Cell suspension cultures for the production of antioxidant phenolic compounds: experiments with tropical highland blackberry (Rubus adenotrichos Schltdl. cv. Vino)

Abstract

Tropical highland blackberries (Rubus adenotrichos Schltdl. cv. Vino) fruits have shown high antioxidant content, including some of the highest known dietary concentrations of ellagitannins, and greater polyphenol accumulation in leaves and stems relative to the fruits. This study aimed to generate a methodology to obtain and quantify antioxidant phenolic compounds from leaf-derived blackberry calli and cellular suspensions. Friable calli and disaggregate cell suspensions were successfully obtained from leaf segments. The effects of three different flask-capping assemblies and six different culture media on blackberry cell culture kinetics was evaluated, as well as total polyphenol concentration, antioxidant capacity, and vanillin and ellagic acid content. The highest yields in terms of biomass (cell viability and fresh weight) were obtained when using homemade cotton plugs for closing the cell suspension flasks, while the Gamborg culture medium supplemented with 20 mg/L of L-glutamine, 200 mg/L of hydrolyzed casein, 5 mg/L of BA and 1 mg/L of IBA promoted a greater accumulation of total polyphenols, a greater antioxidant capacity and presented the highest concentration of vanillin and ellagic acid equivalents. These results correspond to the first bioactive compound quantification and optimization of the tropical highland blackberry cells culture growth conditions, and even though they results are lower than those reported by previous research studies using the fruit or their juice, they are comparable to the ones obtained from cell cultures of other berries.