ESTABLISHMENT OF Strobilanthes crispus IN VITRO CULTURE AND ASSESSMENT OF TARAXEROL CONTENT FROM FIELD AND IN VITRO GROWN PLANTS

Abstract

Taraxerol is a pentacyclic triterpenoid exhibiting various medicinal properties, including antioxidative, anti-fungal, and cytotoxic activities. Strobilanthes crispus, a local Malaysian herb also known as Pecah Beling, accumulates this valuable compound, albeit in low yields. Plant tissue culture provides an alternative approach for the continuous, consistent, and higher-yield production of taraxerol. Therefore, this study aims to establish an in vitro culture from axillary shoot and nodal explants, and to assess the taraxerol content in both in vitro cultures and intact plants. Results showed that 78.0 ± 2.74% of plantlets were successfully established from axillary shoot explants when sterilized with a Clorox™ solution (20% v/v) for nine minutes, whereas no field-sourced nodal explants survived the sterilization treatments. Subsequent micropropagation utilizing in vitro nodal explants supplemented with combined cytokinins (0.5 mg/L KN + 0.1 mg/L TDZ) induced the highest number of shoots (9.4 ± 2.8 shoots per explant), achieving an 86.4 ± 17.24% regeneration frequency after 30 days of culture. For shoot elongation, the MS control medium promoted better elongation (6.60 ± 1.90 cm) compared to cytokinin treatments. Taraxerol content analysis revealed that the leaves of field-grown S. crispus accumulated the highest taraxerol content (48.83 ± 0.18 mg/g dw), followed by in vitro plantlet leaves (45.17 ± 1.25 mg/g dw) and field-grown axillary shoots (26.39 ± 1.14 mg/g dw). These findings provide a vital basis for the further manipulation of taraxerol accumulation using in vitro cultures for large-scale production.