Micropropagation and production of Camptothecin from in vitro plants of Ophiorrhiza rugosa var. decumbens

Abstract

Camptothecin and its derivatives are used as anticancer alkaloids. At present, they are obtained by the extraction from the Chinese tree Camptotheca acuminata and the indigenous tree Nothapodytes foetida. Identification of alternate species of plants like Ophiorrhiza species and development of tissue culture methods may be a suitable alternative for large-scale micropropagation as well as for the production of camptothecin. Plantlets were successfully regenerated from shoot cultures of Ophiorrhiza rugosa initiated from axillary meristems on medium containing benzyladenine (BA) (4.0 mg L⁻¹) + α-naphthalene acetic acid (NAA) (0.05 mg L⁻¹). Rooting was initiated in half concentration of Murashige and Skoog's (MS) basal medium devoid of growth hormones. Tissue culture derived plants of O. rugosa were similar to the normal plants in their morphological characteristics and chemical constitution. Ten O. rugosa plants that were obtained through micropropagation showed when analysed a higher alkaloid content compared to the normal plant. Chemical analysis of the different organs of the tissue culture plant of O. rugosa established in soil indicated 0.002% dry weight of camptothecin in the roots, 0.011% dry weight in the stems, 0.090% dry weight in the leaves and 0.015% in the floral parts.

Keywords:

• micropropagation
• shoot cultures
• camptothecin
• Ophiorrhiza rugosa var. decumbens

Acknowledgements

I am thankful to Dr Susan Eapen, Head of the Plant Secondary Product Section, and Dr S.F. D'Souza, Head of the Nuclear Agriculture and Biotechnology Division, for extending their cooperation to carry out this work.