Metabolomic and antioxidant potential analyses of the rhizome and leaves of Podophyllum hexandrum Royle: A comparative account

Podophyllum hexandrum Royle (Berberidaceae), a high valued medicinal plant with Podophyllotoxin as a pharmacologically active compound. The present study aimed to understand the variability in metabolomic and antioxidant potential of the rhizome and leaves extracts of P. hexandrum. The secondary metabolites from the rhizome and leaves were extracted, quantified and identified using various methods viz. soxhlet reflux extraction method, Folin–Ciocalteu method (λmax 765 nm), Aluminum chloride-colorimetric method (λmax 415 nm), GC-MS and LC-QTOF-HRMS techniques. The antioxidant activity was evaluated using the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method, hydroxyl radical scavenging method, superoxide anion scavenging method, hydrogen peroxide scavenging method and reducing power method. Among the different solvent extracts, the methanolic extract of the rhizome exhibited the highest total phenolic content (164.39 ± 2.92 μg/mL), while the hexane extract showed the lowest content (69.4 ± 2.8 μg/mL). The total flavonoid content was highest in all rhizome extracts compared to the leaf extracts. The GC-MS analysis reported various therapeutic important compound and most of the compound were reported in the rhizome extract. The pharmacologically active compound Podophyllotoxin was only reported in the rhizome extract. Similar to GC-MS analysis, the LC-QTOF-HRMS also reported maximum number of compounds in the rhizome extract. The methanolic extract demonstrated the best antioxidant activity in all the assays conducted. Furthermore, the rhizome displayed the highest antioxidant activity, which can be attributed to its higher polyphenolic content.