GC-MS metabolomics profiling and HR-APCI-MS characterization of potential anticancer compounds and antimicrobial activities of extracts from Picrorhiza kurroa roots

Abstract

The present study explores pharmacological potential and phytochemicals profiling of Picrorhiza kurroa extracts against mammalian cancer cell lines and pathogenic microbes. Bioactive extracts from roots of Picrorhiza kurroa were recovered in the methanol, 50% aqueous dichloromethane (50: 50 v/v) and n-hexane. Antimicrobial activity of the bioactive extracts was assessed against selected strains of bacteria and pathogenic fungi. Aqueous dichloromethane extract showed highest zone of growth inhibition (39.06 ± 1.0 mm) towards Staphylococcus aureus bacteria while methanolic extract showed the lowest inhibition (6.3 ± 4.1 mm) to Escherichia coli bacteria. The tested extracts such as methanol and aqueous dichloromethane exhibited higher inhibition antifungal activity against Aspergillus flavus compared to Fusarium oxysporum. As far as cytotoxicity (MTT assay) of the tested extracts is concerned, n-hexane and aqueous dichloromethane extracts were found to be very active against all cancer cell lines (breast cancer MCF7, MDA-MB-231, SKBR3 and ovarian cancer SKOV3). A preliminary phytochemicals profiling was performed in extracts using GC-MS. Several fractions of active extract were separated with HPLC and analyzed using High Resolution Atmospheric Pressure Chemical Ionization Mass Spectrometry (HR-APCI-MS). Two purified compounds (Dihydromikanolide and 1,3-Dicyclohexyl-4-(cyclohexylimino)-2-(cyclohexylethylamino)-3,4-dihydro-1,3-diazetium) were further evaluated for their anticancer activity against ovarian cancer cell line. Our findings depict that all the tested extracts showed considerable anticancer potential through cell viability assays. The purified compound 1 – Dihydromikanolide from methanolic extract was found to be active against ovarian cancer cells and can be explored as a promising nutra-pharmaceutical candidate against ovarian cancer. However, further studies exploring the molecular pathways and in vivo testing are required.