title: Hydrogen peroxide-induced antioxidant activities and cardiotonic glycoside accumulation in callus cultures of endemic Digitalis species.
abstract: The effect of hydrogen peroxide (H2O2) on callus cultures of four Digitalis species (Digitalis lamarckii, Digitalis trojana, Digitalis davisiana and Digitalis cariensis) increased catalase (CAT), superoxide dismutase (SOD), total phenolic, proline activity and cardiotonic glycoside production. Callus derived from hypocotyl explants was cultured on Murashige and Skoog medium supplemented with 0.25 mg L(-1) indole-3-acetic acid (IAA) and 0.5 mg L(-1) thidiazuron (TDZ). After a month of culture, callus was transferred to MS medium containing 10 mM H2O2 and then incubated for 6 h. The amount of five cardenolides (Lanatoside C, Digitoxin, Digoxigenin, Gitoxigenin and Digoxin) as well as CAT, SOD, total phenolic, proline activity from Digitalis species were compared. No digoxin was detected in all treatments and control groups. The total cardenolides estimated were in the order of D. lamarckii (586.65  μg g(-1) dw), D. davisiana (506.79 μg g(-1) dw), D. cariensis (376.60 μg g(-1) dw) and D. trojana (282.39 μg g(-1) dw). It was clear that H2O2 pre-treatment resulted in an increase in enzymatic and nonenzymatic antioxidants. However, a significant negative relationship between cardenolides production and overall activities of CAT, SOD, total phenolic and proline was evident. The described protocol here will be useful for the development of new strategies for a large-scale production of cardenolides.
authors.affiliation: Abant Izzet Baysal University, Department of Biology, Bolu 14280, Turkey. Electronic address: guncesahin@gmail.com.
authors.forename: Gunce Sahin
authors.initials: GS
authors.lastname: Cingoz
authors.affiliation: Abant Izzet Baysal University, Department of Biology, Bolu 14280, Turkey.
authors.forename: Sandeep Kumar
authors.initials: SK
authors.lastname: Verma
authors.affiliation: Abant Izzet Baysal University, Department of Biology, Bolu 14280, Turkey.
authors.forename: Ekrem
authors.initials: E
authors.lastname: Gurel
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D004070:Digitalis / Q000187:drug effects / Q000378:metabolism*; D006027:Glycosides / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007210:Indoleacetic Acids / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D006027:Glycosides; D007210:Indoleacetic Acids; C030737:indoleacetic acid; D006861:Hydrogen Peroxide; D002374:Catalase
keywords: Antioxidant activity; Cardenolides accumulation; Digitalis L.; Foxglove; Hydrogen peroxide