Metabolite profiling, antioxidant, and in vitro wound healing activities of Citrus medica L. and Citrus x microcarpa Bunge peels and leaves essential oils

Wound care is still dominated by the use of synthetic chemicals such as anti-inflammatory drugs, corticosteroids and antibiotics which have many shortcomings. One potential alternative to be developed is essential oils. Citrus are members of the Rutaceae family which contain essential oils. Citrus medica L. and Citrus x microcarpa Bunge are distributed in West Sumatra and research on wound healing activity is still lacking. Therefore, this study aims to identify the metabolite profiles of essential oils of two species of citrus using FTIR spectroscopy and GC-MS as well as evaluate their antioxidant activity and determine their wound healing activity. Essential oils were obtained by the hydrodistillation method. Metabolite fingerprinting and profiling were carried out by using FTIR and GC-MS methods. Antioxidant activity was determined using the ABTS and FRAP methods while wound healing used the MTT Assay and Scratch Assay. The result showed the secondary metabolites of Citrus medica peels (LPEO) and Citrus medica leaves (LLEO) essential oil contained D-limonene and citral. Meanwhile Citrus x microcarpa leaves (MLEO) contain β-pinene, germacrene D, and elemol and Citrus x microcarpa peels essential oil (MPEO) consists of D-limonene, β-pinene, and germacrene D. MLEO has stronger antioxidant activity than MPEO, LPEO and LPEO with ABTS and FRAP method with IC50 197.051 µg/mL and 8.04 Fe (II)/mg sample and is followed by LLEO. Testing of wound healing activity using MTT assay showed that MPEO significantly increased cell proliferation. Meanwhile, the highest wound closure was found at a concentration of 0.1 µg/mL for MLEO followed by LPEO at 77.54% and 73.71% using scratch assay method. It can be concluded that essential oils of Citrus medica and Citrus x microcarpa can increase cell proliferation and migration so that they have potential to be developed as an alternative in wound healing.