Effect of anti-oxidants and adsorbents on tissue browning associated metabolism in Cocculus pendulus callus cultures.

Explants and callus of C. pendulus produced intense brown substances in the medium which caused necrosis. Various anti-oxidants (ascorbic acid, cysteine and dithiothreitol) and adsorbents (activated charcoal and polyvinyl pyrrolidone) were used in different concentrations to prevent browning of the tissues. These in MS medium affected differently the growth, colour and texture of the tissues. It was concluded that both peroxidase and phenolase were involved in the browning. Increased peroxidase activity and decreased phenolase activity were probably due to more peroxidative oxidation of phenols and unavailability of substrate for phenolase activity. This resulted in faster growth of tissues, which further reduced the phenolase activity.