Investigation of cytotoxic and antioxidant activities of Michauxia campanuloides L'Hérit. ex Aiton

Michauxia campanuloides L'Hérit. ex Aiton (Campanulaceae) is one of the traditionally used plants growing in Southern Anatolia. This study aimed to evaluate in vitro cytotoxic and antioxidant activities of the extracts derived from M. campanuloides aerial parts and roots, as well as to identify their phytochemical composition. The in vitro cytotoxic activity of MeOH extract as well as n-hexane, EtOAc, n-BuOH and H2O subextracts prepared from roots and aerial parts of M. campanuloides were evaluated against colon (HCT116 and SW480), breast (MDA-MB-231 and HCC1937) and liver (HEP3B and HEPG2) cancer cell lines and fibroblastic L929 healthy cell line by MTS assay. EtOAc subextract of roots exhibited the highest cytotoxic activity against all studied cell lines with the IC50 values of 10-154.76 μg/mL. ABTS, DPPH, FRAP and CUPRAC methods were used for in vitro antioxidant activity studies. Total phenolic and flavonoid contents of the extracts were also determined. EtOAc subextracts of aerial parts (For ABTS test, 353.399±19.206 mg TE/g) and roots (For ABTS test, 367.651±16.382 mg TE/g) showed significant antioxidant activity. Extracts having high TPC and TFC values showed remarkable antioxidant activity. Total flavonoid content of n-BuOH subextract of aerial parts was higher than other subextracts. HPTLC was used for comparative identification of compounds in the extracts, and the identified compounds (rutin, chlorogenic acid, neochlorogenic acid, isoquercitrin, astragalin, caffeic acid and quercetin) were also quantified by UPLC. Astragalin (93.37±0.11 mg/g) and isoquercitrin (51.22±0.81 mg/g) were predominant in EtOAc subextract of aerial parts showing the significant antioxidant activity. Although EtOAc root subextract exhibited the best cytotoxicity, most of its metabolites were not characterised. Therefore, the potential major active compounds in EtOAc subextract of roots deserve further isolation and structural elucidation studies.