Characterisation of two phenotypes of Centella asiatica in Southern Africa through the composition of four triterpenoids in callus, cell suspensions and leaves

Abstract

Two morphologically distinct phenotypes of Centella asiatica (Type-1 and Type-2) in South Africa were compared in relation to the levels of triterpenoid saponins with the aim of assessing their potential for biotechnological manipulation of triterpenoid synthesis. The metabolites investigated included madecassoside and asiaticoside and their sapogenins madecassic-and asiatic acid; produced in cultured undifferentiated cells (cell suspensions and calli) and leaves. Weight determination in plant cell suspensions and the accumulation of secondary metabolites after 16 days for Type-1 and 20 days for Type-2 were investigated since these secondary metabolites accumulate during the period that follows the active growth phase. The four triterpenoids of interest were analysed and quantified by HPLC in crude ethanolic extracts. A difference in bioactive triterpenoids was exhibited that was tissue specific and varied between the two phenotypes. The triterpenoids from leaf tissue were more easily quantifiable in each phenotype than in the case of the undifferentiated cells (callus and cell suspensions), which had lower, but still quantifiable, levels of these targeted secondary metabolites. Leaves contained the highest triterpenoid levels (ranging from 1.8 to 5% dry weight for the triterpenoid acids and their glycosides, respectively), with the free acids occurring in a ratio of approximately 1:2.5 in relation to the glycoside content.

The Influence of Certain Taxonomic and Environmental Parameters on Biomass Production and Triterpenoid Content in the Leaves of Centella asiatica (L.) Urb. from Madagascar

“…The observation of greater active ingredient content in morphotype A compared to morphotype B may support the findings by James et al [25], who estimated the triterpenoid content of leaves of morphotype B harvested in South Africa at between 1.8 and 5%. These findings corroborate those of Rouillard-Guellec et al [3], who estimate that leaves of Malagasy origin (morphotype A) could be three to seven times richer in triterpenoids than those of Indian origin.…”

“…Morphotype B (round leaves) seems to be widely distributed across Southeast Asia and Africa and could be the type species [25]. Morphotype A (reniform leaves), contrary to that stated by Boiteau [7], seems more specific to Madagascar.…”

Effect of Plant Growth Regulators on Callus, Cell Suspension and Cell Line Selection for Flavonoid Production from Pegaga (<i>centella asiatica</i> L. urban)

“…However, in some cases, the production of secondary products did not show a positive correlation with the maximal growth rate of the culture (Jacinda et al, 2008). Various reports have indicated that maximum production of flavonoid's achieved during the active growing stage of the cells (Zhao et al, 2001;Antonigni et al, 2007;Fu et al, 2005).…”

“…It showed that higher concentrations of BAP gave better callus proliferation rates. Furthermore, a study by Jacinda et al (2008) revealed that they maintained the C. asiatica callus in the MS medium supplemented with 0.22 mg L −1 2,4-D and 0.23 mg L −1 BAP and managed to produce triterpenoids. It was found that TDZ generally tended to promote the formation of compact-green nodular callus (Murthy et al, 1998).…”

“…Callus induction of C. asiatica has been carried out previously by Nath and Buragohain (2005) and Jacinda et al (2008). However, both of the published articles were focused on triterpenoid production.…”