Primary metabolites, phenolics content and antioxidant activities of Hydrocotyle bonariensis and Centella asiatica

Hydrocotyle bonariensis or locally known as" Pegaga Embun," is a creeping herb from the family Araliaceae. H. bonariensis is closely related to Centella asiatica (Apiaceae), which is commonly known as "Pegaga Kampung" due to their morphological characteristics. In most studies on phytochemical properties, C. asiatica is more popular than H. bonariensis. Extensive studies have been conducted on the phytochemical and biological activities of C. asiatica; however, a minimal study has been conducted on H. bonariensis. Hence, this study was carried out to compare the primary metabolites, phenolics content, and antioxidant activities of the fresh and dry samples of H. bonariensis and C. asiatica. All the analyses were conducted via in vitro assay and were measured using a UV-Vis spectrophotometer. The highest total soluble protein and ascorbic acid content were produced by the fresh sample of C. asiatica with 23.28 mg protein/ g FW and 0.35 mg ascorbic acid/g FW and H. bonariensis fresh sample produced 2.80 mg protein/g FW and 0.34 mg ascorbic acid/g FW, respectively. Meanwhile, the highest total reducing sugar and hydrolyzed sugar were recorded from the fresh sample of H. bonariensis with 1.94 mg reducing sugar/g FW and 3.84 mg hydrolyzed sugar/g FW, respectively. In the phenolics content analysis, the highest total phenolics and flavonoids were exhibited by fresh H. bonariensis with 0.96 mg GAE/g and 13.79 mg CE/g DW (dry weight), respectively. Furthermore, the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition was recorded from the fresh sample of C. asiatica with 91%, and the highest ferric reducing antioxidant power (FRAP) value was recorded from the fresh sample of C. asiatica with 66.75 mg TE/g FW. In conclusion, H. bonariensis showed high potential in bioactive compound production and as a source of antioxidants. Hence, an extensive study on H. bonariensis should be conducted to increase the medicinal values of H. bonariensis.