Phenolics from Barleria cristata var. Alba as carcinogenesis blockers against menadione cytotoxicity through induction and protection of quinone reductase

Ali M El-Halawany,Hossam M Abdallah,Ahmed R Hamed,Hany Ezzat Khalil,Ameen M Almohammadi

doi:10.1186/s12906-018-2214-9

Abstract

BackgroundThere are increasing interests in natural compounds for cancer chemoprevention. Blocking agents represent an important class of chemopreventive compounds. They prevent carcinogens from undergoing metabolic activation and thereby suppressing their interaction with cellular macromolecular targets.MethodsThe effect of phenolic compounds isolated from Barleria cristata var. alba as chemopreventive agent was evaluated. The ethyl acetate fraction of B. cristata was subjected to different chromatographic techniques for isolation of its major phenolic compounds. The isolated compounds were evaluated for their potential to induce the cancer chemopreventive enzyme marker NAD(P)H quinonereductase 1 (NQO1) in murine Hepa-1c1c7 cell model.ResultsThe ethyl acetate fraction of B. cristata var. alba yielded five known compounds identified as verbascoside (1), isoverbascoside (2), dimethoxyverbascoside (3), p-hydroxy benzoic acid (4), and apigenin-7-O-glucoside (5). Among the tested compounds, isoverbascoside (2) was shown to potently induce the activity of the enzyme in a dose –dependent manner. As a functional assay for detoxification, compound 2 was the strongest to protect Hepa-1c1c7 against the toxicity of menadione, a quinone substrate for NQO1.ConclusionThis effect seemed to be attributed to the compound’s potential to induce both the catalytic activity and protein expression of NQO1 as revealed by enzyme assay and Western blotting, respectively.

Highlights

There are increasing interests in natural compounds for cancer chemoprevention
Blocking agents elicit chemopreventive actions through the induction of a set of phase II detoxifying and antioxidant enzymes such as the chemopreventive marker NAD(P)H quinonereductase 1 (NQO1 or QR1), glutathione-stransferase (GST), UDP-glucuronosyltransferase (UGT), γ-glutamate cysteine ligase (γ -GCL), glutathione reductase (GR), catalase and Mn superoxide dismutase which act in the detoxification and elimination of harmful reactive intermediates and oxidative stress [5]
Induction of NQO1 activity by B.Cristata var. alba phenolic constituents In the present study, we evaluated compounds (1, 2, 4 & 5) isolated from B. cristata for their potential to induce the cancer chemopreventive marker enzyme NQO1 in murine Hepa-1c1c7 cells

Summary

Introduction

There are increasing interests in natural compounds for cancer chemoprevention. Blocking agents represent an important class of chemopreventive compounds. They prevent carcinogens from undergoing metabolic activation and thereby suppressing their interaction with cellular macromolecular targets. Blocking agents is one important class of compounds in chemoprevention They prevent carcinogens from undergoing metabolic activation and thereby suppressing their interaction with cellular macromolecular targets such as DNA, RNA and proteins. There have been accumulating evidences for the promising value of natural products in chemoprevention against cancer. The reason for this is largely due to their low toxicity and high diversity of their chemical structures [6]

Methods

Results

Discussion

Conclusion