Phytochemicals Analysis in Callus, Tissue Cultured and Conventionally Propagated Plant Roots, and Cell Culture of Plumbago indica L.

Abstract

Aims: Plumbago indica L. commonly known as rose-coloured leadwort in English is widely used in the treatment of rheumatism, paralysis, leprosy, headache, leukoderma, enlarged glands, scorpion-sting, cancer, ophthalmia, secondary syphilis, dyspepsia, haemorrhage, piles, flatulence and loss of appetite etc. in traditional medicinal systems. Plumbagin is one of the major phytochemicals that is responsible for most of the above biological activities of P. indica. This plant is gradually decreasing from its natural habitats due to over exploitation for medicinal purposes. The use of tissue culture plants for mass scale cultivation and phytochemical extraction can protect P. indica that grows in the natural environment. The development of cell culture allows extracting plumbagin without growing plants in the field. 
 Study Design: Quantitative and qualitative comparison of phytochemicals in tissue cultured and conventionally propagated P. indica plant roots and callus was done using HPLC and GC-MS analysis.
 Methodology: The amount of plumbagin present in eight months old field-grown tissue cultured and conventionally propagated (shoot cutting) plant roots, callus, and cell culture were quantified by HPLC analysis and phytochemicals were identified qualitatively using GC-MS analysis.
 Results: Conventionally propagated plant root extract had the highest plumbagin content 23.53 \(\pm\)5.34 \(\mu g\)/mL when compared with tissue cultured plant roots (12.90 \(\pm\)2.42 \(\mu g\)/mL), callus (0.009 µg/mL), cell culture pellet (0.015 \(\pm\)0.01 \(\mu g\)/mL) and cell culture supernatant extract (4.23 \(\pm\)2.07 \(\mu g\)/mL). The GC-MS analysis revealed that conventionally propagated plant root extract contained a higher number of phytochemicals (16) while tissue cultured plant roots contained only four. Callus extract contained only n-Hexadecanoic acid. Nine phytochemicals were detected in cell culture pellet extract while only three phytochemicals were detected in the supernatant.
 Conclusion: Tissue cultured P. indica roots can be also used as a source to extract plumbagin in mass scale, yet conditions need to be optimized in order to produce high level of plumbagin. The study confirmed not only the possibility of obtaining plumbagin through cell cultures in a bioreactor system but also products that are mainly secreted into the medium.