Effect of Antioxidants on Callus Browning of Glycyrrhiza glabra

Objective: In the present study, adsorbents and antioxidants incorporated in to callus cultures of Glycyrrhiza glabra to study their potency in checking callus browning. Methods: Activated charcoal was added as an adsorbent at varying concentrations of 100, 500 and 1000 mg/l. Ascorbic acid and cysteine were added as antioxidants each at concentrations of 50, 100 and 150 mg/l grown on Modified MS basal medium supplemented with growth regulators (BA, Kn, IAA, NAA). Result: Browning was effectively controlled by activated charcoal and ascorbic acid while cysteine did not show any inhibition. Discussion: Browning is a major problem affecting tissue culture studies of medicinal plants containing polyphenolic compounds that cause oxidation reactions leading to browning. Hence browning could be controlled by using adsorbents that adsorb the oxidative by products or by using antioxidants that prevent the oxidation reactions.