Biotechnological approaches for the production of camptothecin

Abstract

Camptothecin (CPT), an indole alkaloid popular for its anticancer property, is considered the third most promising drug after taxol and famous alkaloids from Vinca for the treatment of cancer in humans. Camptothecin was first identified in Camptotheca acuminata followed by several other plant species and endophytic fungi. Increased harvesting driven by rising global demand is depleting the availability of elite plant genotypes, such as Camptotheca acuminata and Nothapodytes nimmoniana, crucial for producing alkaloids used in treating diseases like cancer. Conservation of these genotypes for the future is imperative. Therefore, research on different plant tissue culture techniques such as cell suspension culture, hairy roots, adventitious root culture, elicitation strategies, and endophytic fungi has been adopted for the production of CPT to meet the increasing demand without affecting the source plant's existence. Currently, another strategy to increase camptothecin yield by genetic manipulation is underway. The present review discusses the plants and endophytes that are employed for camptothecin production and throws light on the plant tissue culture techniques for the regeneration of plants, callus culture, and selection of cell lines for the highest camptothecin production. The review further explains the simple, accurate, and cost-effective extraction and quantification methods. There is enormous potential for the sustainable production of CPT which could be met by culturing of suitable endophytes or plant cell or organ culture in a bioreactor scale production. Also, different gene editing tools provide opportunities for engineering the biosynthetic pathway of CPT, and the overall CPT production can be improved . KEY POINTS: • Camptothecin is a naturally occurring alkaloid with potent anticancer properties, primarily known for its ability to inhibit DNA topoisomerase I. • Plants and endophytes offer a potential approach for camptothecin production. • Biotechnology approaches like plant tissue culture techniques enhanced camptothecin production.

Keywords: In vitro production; Nothapodytes Nimmoniana; Camptotheca acuminata; Camptothecin; Extraction; Quantification.

Fig. 1

Mechanism of inhibition of Topoisomerase I activity by camptothecin

Fig. 2

Structure of camptothecin and its derivatives/analogues (Martino et al. 2017)

Fig. 3

The biosynthetic pathway of camptothecin involves the pre-strictosidine, strictosidine synthesis, and post-strictosidine pathways. TIA, monoterpenoid indole alkaloid; MEP, 2 C-methyl-D-erythritol-4-phosphate; STR, strictosidine synthases. The multiple step reaction is represented by an arrow with a dotted shaft (Sirikantaramas et al. 2013)

Fig. 4

Production of CPT from various tissue culture techniques