In vitro plant regeneration, phenolic compound production and pharmacological activities of Coleonema pulchellum

Effects of plant growth regulators (PGRs) and organic elicitors (OEs) on Coleonema pulchellum in vitro micropropagation, secondary product production and pharmacological activities were evaluated. In vitro, ex vitro and parental plants of C pulchellum were investigated for their potential to produce phenolic and pharmacological compounds. Different morphogenic characteristics of shoots were obtained with PGRs- and OEs-containing media. A higher number of normal shoots were achieved with a low concentration of thidiazuron (TDZ: 4.5 mu M). Lesser numbers were found with combinations of TDZ (13.6 mu M) + indole-3-acetic acid (IAA: 2.9 mu M); haemoglobin (HB: 300 mg 1(-1)) or glutamine (GM: 40 mu M) + benzyladenine (BA: 8.8 mu M). Shoots were rooted in vitro and successfully acclimatized. Plant growth regulators and OEs had a significant effect on the synthesis and accumulation of phenolic compounds and flavonoids. In particular, casein hydrolysate (CH) as well as a combination of GM and BA induced high levels of total phenolics and flavonoids during in vitro culture. Cytokinins and OEs had a significant effect on DPPH radical scavenging and antibacterial activities of C pulchellum extracts. Acclimatized C pulchellum plants can be used as substitute alternative to natural populations. (C) 2013 SAAB. Published by Elsevier B.V. All rights reserved.