HPLC-DAD-ESI-MS/MS characterization of bioactive secondary metabolites from Strelitzia nicolai leaf extracts and their antioxidant and anticancer activities In vitro

Pharmacognosy Research,2018,10,4,368-378.DOI:10.4103/pr.pr_89_18Published:October 2018Type:Original ArticleAuthors:Mosad Ghareeb, Amal Saad, Wafaa Ahmed, Laila Refahy, and Sami Nasr Author(s) affiliations:Mosad Ghareeb1, Amal Saad1, Wafaa Ahmed2, Laila Refahy1, Sami Nasr3 1Department of Medicinal Chemistry, Theodor Bilharz Research Institute, Giza, EGYPT. 2Department of Medicinal Chemistry, Theodor Bilharz Research Institute, Giza, Egypt; Department of Chemistry, College of Science and Arts, Sajir, Shaqra University, Shaqra, KSA. 3Department of Biochemistry and Molecular Biology, Theodor Bilharz Research Institute, Giza, EGYPT. Abstract:Background: Strelitzia nicolai Regel and Körn (Strelitziaceae) is native to Southern Africa whose phytochemistry and pharmacology were slightly investigated. Materials and Methods: In the current work, different solvent extracts of S. nicolai were screened for their chemical profiles through high‑performance liquid chromatography coupled with diode array detection and electrospray ionization mass spectrometry (HPLC‑DAD‑ESI‑MS/MS) analyses. Furthermore, their in vitro antioxidant, cytotoxic, and anticancer activities were evaluated using 2,2’‑diphenyl‑1‑picrylhydrazyl radical (DPPH), 2,2’‑azino‑bis (3‑ethylbenzothiazoline‑6‑sulphonic acid) (ABTS) & ferric reducing antioxidant power (FRAP) and crystal violet staining (CVS) colorimetric assays, respectively. Results: HPLC‑DAD‑ESI‑MS/MS analyses led to the identification of nineteen and eleven phenolic compounds from the ethyl acetate and n‑butanol extracts, respectively including flavonoids (e.g., quercetin 3‑(2 G‑rhamnosylrutinoside, quercetin, quercetin‑3‑O‑glucoside, kaempferol‑3,7‑O‑dirhamnoside, isorhamnetin‑3‑O‑rutinoside and kaempferol‑3‑O‑glucoside), phenolic acids derivatives (e.g., chlorogenic acid glycoside, protocatechuic acid‑O‑glucoside and caftaric acid ), chalcones (e.g., xanthoangelol), and phenylethanoids (e.g., ligstroside glucoside). Moreover, in the DPPH assay the IC50 value of the most active ethyl acetate extract was 20.49 μg/mL, relative to 2.92 μg/mL of ascorbic acid. ABTS and FRAP results reinforced the results of DPPH assay. According to the National Cancer Institute criteria, the tested extracts showed weak to moderate cytotoxic activities with IC50 values ranged from 65.23 to 451.29 μg/ mL. Furthermore, the EtOAc and n‑BuOH extracts showed a noticeable anticancer activity with CVS spectroscopic readings for liver hepatocellular carcinoma growth 0.806 and 0.684 at a concentration (125 μg/mL), as well as 0.730 and 0.618 at concentration (500 μg/mL), respectively against control at 1.022. Conclusion: The obtained results reveal the high efficacy of the phenolic‑rich extracts from S. nicolai as naturally occurring antioxidant and anti‑tumor agents. Keywords:Anticancer activity, Antioxidant activity, cytotoxicity, HPLC‑DAD‑ESI‑MS/MS, Polyphenolics, Strelitzia nicolaiView:PDF (2.44 MB)