Chemical composition, antioxidant and cytoprotective potentials of Carica papaya leaf extracts: A comparison of supercritical fluid and conventional extraction methods

Boon Khor Keat Khor, Nelson Jeng Yeou Chear, Juzaili Azizi, Kooi Yeong Khaw

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    The leaves of Carica papaya (CP) are rich in natural antioxidants. Carica papaya has traditionally been used to treat various ailments, including skin diseases. This study aims to decipher the antioxidant effects and phytochemical content of different CP leaf extracts (CPEs) obtained using supercritical carbon dioxide (scCO2) and conventional extraction methods. The antioxidant activities of CPEs were evaluated by cell-free (1,1-diphenyl-2-picryl-hydrazyl (DPPH) and ferric-reduced antioxidative power (FRAP)) and cell-based (H2O2) assay. Both C. papaya leaf scCO2 extract with 5% ethanol (CPSCE) and C. papaya leaf scCO2 extract (CPSC) exhibited stronger DPPH radical scavenging activity than conventional extracts. In the FRAP assay, two hydrophilic extracts (C. papaya leaf ethanol extract (CPEE) and C. papaya freeze-dried leaf juice (CPFD)) showed relatively stronger reducing power compared to lipophilic extracts. Cell-based assays showed that CPFD significantly protected skin fibroblasts from H2O2-induced oxidative stress in both pre-and post-treatment. CPEE protected skin fibroblasts from oxidative stress in a dose-dependent manner while CPSCE significantly triggered the fibroblast recovery after treatment with H2O2. GC-MS analysis indicated that CPSCE had the highest Α-tocopherol and squalene contents. By contrast, both CP hydrophilic extracts (CPEE and CPFD) had a higher total phenolic content (TPC) and rutin content than the lipophilic extracts. Overall, CPEs extracted using green and conventional extraction methods showed antioxidative potential in both cell-based and cell-free assays due to their lipophilic and hydrophilic antioxidants, respectively.

    Original languageEnglish
    Article number1489
    Number of pages18
    JournalMolecules
    Volume26
    Issue number5
    DOIs
    Publication statusPublished - 9 Mar 2021

    Keywords

    • Antioxidant activities
    • Carica papaya
    • Co-solvent
    • Hydrogen peroxide
    • Rutin
    • Skin fibroblast
    • Squalene
    • Supercritical carbon dioxide
    • α-tocopherol

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