Determination of cytotoxic, antioxidant activities and LC/MS-MS profiles of three endemic Verbascum L. species

Abstract

The Verbascum genus includes many species used in folk medicine or the treatment of various diseases. In this study, the cytotoxic, antioxidant activity, and LC/MS-MS profiles of three Verbascum species, which are endemic in Eskişehir and its surroundings, were investigated. The cytotoxic effects of methanol extract of V.detersile, V. eskisehirensis, and V.gypsicola species on the cervical (HeLa) and ovarian cancer (SKOV-3) cells were investigated using a colorimetric assay. The results indicated that cytotoxic effect was not observed after treatment of SKOV-3 cells with Verbascum. On the other hand, the cytotoxic activity of V. detersile was found to be 0.1910 mg/dL and 1.057 mg/dL for HeLa cells after 24 or 48 hours incubation with V.detersile, respectively. The antioxidant activity was determined as 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical scavenging activity, trolox equivalent antioxidant capacity (TEAC assay), and also the total phenolic content of the samples was found. Total phenols were estimated as Gallic acid equivalents (GAE), expressed as mg Gallic acid/in 1g extract previously described by Singletton. LC/MS profiles separation and detection of phytochemicals of the extract were performed on a Shimadzu UPLC system consisting of a vacuum degasser, an autosampler (SIL20A Shimadzu Autosampler), a binary pump (LC20AD Shimadzu), an oven (CTO20A Shimadzu Column Oven) and DAD dedector (SPD M20A Shimadzu DAD Detector). In terms of antioxidant activity, V. gypsicola was found to have the least antioxidant activity among the three extracts, which is also correlated with the total amount of phenolic content in its content. In this way, it differs from other species. V. detersile exhibits a different chemical profile from the other two species with the iridoid catalpol derivatives it contains. Apigenin pentoside is the only flavonoid molecule detected in V. detersille.