OBJECTIVE: We aimed to compare the phytochemical composition of 7 varieties growing in different conditions at various geographical locations. We also aimed to establish the quality control markers for the authentication of these varieties.
METHODS: We applied untargeted UHPLC-TOFMS metabolomics to discriminate 100 leaf samples of F. deltoidea collected from 6 locations in Malaysia. A genetic analysis on 21 leaf samples was also performed to validate the chemotaxonomy differentiation.
RESULTS: The PCA and HCA analysis revealed the existence of 3 chemotypes based on the differentiation in the flavonoid content. The PLS-DA analysis identified 15 glycosylated flavone markers together with 1 furanocoumarin. These markers were always consistent for the respective varieties, regardless of the geographical locations and growing conditions. The chemotaxonomy differentiation was in agreement with the DNA sequencing. In particular, var. bilobata accession which showed divergent morphology was also differentiated by the chemical fingerprints and genotype.
CONCLUSION: Chemotype differentiation based on the flavonoid fingerprints along with the proposed markers provide a powerful identification tool to complement morphology and genetic analyses for the quality control of raw materials and products from F. deltoidea.
MATERIALS AND METHODS: Cytotoxicity screening of chalepin against MCF7 cells was conducted using SRB assay. Apoptosis induction was examined by established morphological and biochemical assays including phase contrast and Hoechst/PI staining fluorescence microscope. Similarly, Annexin-V/FITC and TUNEL assays were conducted using flow cytometry whereas caspase-3 activity was evaluated using microplate reader.
KEY FINDINGS: The result indicates remarkable cytotoxic activity against MCF7 cells, whereas it shows moderate cytotoxic activity against MDA-MB231 cells. Interestingly, chalepin did not present any toxicity against MRC5 normal cell line. Morphological examination using both phase contrast and fluorescence microscope displays typical apoptotic features such as membrane blebbing, DNA fragmentation, chromatin condensation and apoptotic bodies' formation following chalepin treatment against MCF7 cells at different concentration for 48 h. Apoptosis induction is significantly associated with externalisation of phosphatidylserine, and DNA fragmentation in MCF7 cells chalepin treated cells when compared with control. The protein expressions of caspase-8, 9 and cleaved PARP1 were upregulated which correlated well with increased caspase-3 activity.
SIGNIFICANCE: From our recent findings, chalepin was able to induced apoptosis in MCF7 cells and therefore, could be evaluated further as a potential source of anticancer agent for cancer treatment such as breast cancer.