LC-ESI-MS/MS Alkaloidal Profiling and Biological Investigation of <I>Cleistocactus winteri </i>Stems

Abstract

Cleistocactus winteri is a succulent plant of the Cactaceae family, commonly known as the golden rat tail. Many members of the Cactaceae family are the focus of chemical and biological studies as they contain bioactive compounds, well known for their health-related properties. We aimed to investigate Cleistocactus winteri stems both phytochemically and biologicallyfor the first timeincluding three biological effects. For the evaluation of theanti-inflammatory activity, Nitric oxide (NO) inhibition on lipopolysaccharide (LPS) stimulated Raw murine microphages (RAW 264.7) cell model was used. The cytotoxic activity was evaluated against hepatocarcinoma (HepG2), breast adenocarcinoma (MCF-7), colorectal carcinoma (HCT-116), and colon adenocarcinoma (CACO 2) human cancer cell lines using MTT (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide) assay. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Seven alkaloids were tentatively identified based on Mass bank on line library in addition to the isolation and identification of four known flavonoids and a β-sitosterol 3- O-glucoside from the studied extract. The stem methanol extract showed a 6% inhibition of NO production (up to 48 μmol/L). Furthermore, the IC50 of the total alkaloid fraction against HepG2, MCF-7, and CACO-2 cell lines was equal to 26.53, 23.8, and 13.07 µg/mL, respectively, while that of the methanol extract against Hep-G2 and HCT-116 was 181 µg/mL and 357 µg/mL, respectively with no effect against MCF-7 cell line. The antioxidant effect of the extract was about one third (112 µg/mL) that of ascorbic acid.