In Vitro Multiplication and Phenolic Content Quantification of Hydrocotyle bonariensis (Pennywort) In Vitro Propagated Leaves

Hydrocotyle bonariensis is a pennywort from the family Araliaceae commonly known as “pegaga embun” among Malay community in Malaysia. H. bonariensis is closely related to Centella asiatica due to its morphological characteristics. However, both plant species are from different families. Among all the pennywort species, C. asiatica is the most popular with high number of research that has been undertaken compared to H. bonariensis. The availability of wild H. bonariensis in nature is unidentified due to low interest on this plant species. Hence, this study was carried out to propagate H. bonariensis via in vitro technique and to evaluate the antioxidant properties of H. bonariensis. The nodal segments of H. bonariensis were used as explants for the multiplication experiment that was conducted using Murashige and Skoog (MS) media supplemented with 6-benzylaminopurine (BAP), thidiazuron (TDZ) and kinetin (Kin) at concentrations of 0, 2.5, 5.0, 7.5 and 10.0 mg/L. After 6 weeks of inoculation, the plants were harvested and total polyphenol, phenolic acid and flavonoid contents were analysed using Folin-Ciocalteu and aluminum chloride colorimetric methods. The results of this study showed that 10 mg/L of BAP was the best cytokinin concentration for multiplication of H. bonariensis. For the antioxidant analysis, the highest total polyphenol content was recorded from 2.5 mg/L BAP treatment with 1.67 mg GAE/g DW. Meanwhile, the highest total phenolic acid and flavonoid contents were recorded from TDZ treatment with 3.22 mg GAE/g DW (10 mg/L) and 9.03 mg RE/g DW (7.5 mg/L), respectively. In conclusion, plant tissue culture technique would be recommended for large-scale production of plantlets and secondary metabolites for H. bonariensis.