Analysis of anticancer compound,indole-3-carbinol,in broccoli using a new ultrasound-assisted dispersive-filter extraction method based on poly(deep eutectic solvent)-graphene oxide nanocomposite

Indole-3-carbinol(I3C),an important anticancer compound found in broccoli,has attracted considerable attention.The rapid extraction and accurate analysis of I3C in the pharmaceutical industry in broccoli is challenging as I3C is unstable at low pH and high temperature.In this study,a rapid,accurate,and lowcost ultrasound-assisted dispersive-filter extraction(UADFE)technique based on poly(deep eutectic solvent)-graphene oxide(PDES-GO)adsorbent was developed for the isolation and analysis of I3C in broccoli for the first time.PDES-GO with multiple adsorption interactions and a fast mass transfer rate was synthesized to accelerate adsorption and desorption.UADFE was developed by combining dispersive solid-phase extraction(DSPE)and filter solid-phase extraction(FSPE)to realize rapid extraction and separation.Based on the above two strategies,the proposed PDES-GO-UADFE method coupled with high-performance liquid chromatography(HPLC)allowed the rapid(15-16 min),accurate(84.3%-96.4%),and low-cost(adsorbent:3.00 mg)analysis of I3C in broccoli and was superior to solid-phase extraction,DSPE,and FSPE methods.The proposed method showed remarkable linearity(r=0.9998;range:0.0840-48.0 mg/g),low limit of quantification(0.0840 mg/g),and high precision(relative standard deviation<5.6%).Therefore,the PDES-GO-UADFE-HPLC method shows significant potential in the field of pharmaceutical analysis for the separation and analysis of anti-cancer compounds in complex plant samples.

Effects of Indole-3-Carbinol and Flavonoids Administered Separately and in Combination on Nitric Oxide Production and iNOS Expression in Rats

Beneficial effects of natural compounds are often attributed to modulation of NO production;however effects produced by plant extracts do not correlate with effects of purified components. The goal of our work was to study ability of flavonoids and indole-3-carbinol, as well as their combinations to modify NO production, iNOS gene and protein expression in rat tissues. Baicalein and luteolin decreased NO concentration in both intact and LPS-treated animals. Baicalein decreased iNOS gene expression. Luteolin decreased NO production in the liver and heart and number of iNOS-positive cells in the liver of LPS-treated animals. Combination of the two substances did not decrease the NO synthesis triggered by LPS, although it decreased iNOS gene expression. Quercetin decreased NO production in the heart, kidneys and blood of intact rats, but enhanced the LPS effect in testes, spleen and blood on NO production and iNOS protein expression in the liver. Indole-3-carbinol decreased NO concentration in the cerebellum, blood, lungs and skeletal muscles. The drug enhanced the LPS-triggered increase of NO production in all rat organs. It increased iNOS protein expression in intact liver;however it decreased the LPS-triggered outburst of the enzyme biosynthesis. Combination of indole3-carbinol with quercetin decreased NO production in LPS-treated animals however it slightly increased iNOS gene expression. Taken together our results suggest that modifications of NO level in tissues by a natural compound cannot be predicted from data about its effects on NOS expression or activity. Combination of substances can produce an effect differing from that of individual substances. This stresses importance of direct measurements of NO in the tissues.

Multiple therapeutic and preventive effects of 3,3'-diindolylmethane on cancers including prostate cancer and high grade prostatic intraepithelial neoplasia

Cruciferous vegetables belong to the plant family that has flowers with four equal-sized petals in the pattern of a crucifer cross.These vegetables are an abundant source of dietary phytochemicals,including glucosinolates and their hydrolysis products such as indole-3-carbinol（I3C） and 3,3＇-diindolylmethane（DIM）.By 2013,the total number of natural glucosinolates that have been documented is estimated to be 132.Recently,cruciferous vegetable intake has garnered great interest for its multiple health benefits such as anticancer,antiviral infections,human sex hormone regulation,and its therapeutic and preventive effects on prostate cancer and high grade prostatic intraepithelial neoplasia（HGPIN）.DIM is a hydrolysis product of glucosinolates and has been used in various trials.This review is to provide an insight into the latest developments of DIM in treating or preventing both prostate cancer and HGPIN.

Bioactive Alkaloids from Indole-3-carbinol Exposed Culture of Daldinia eschscholzii

Two new and rare bioactive indoles named dalesindoloids A （1） and B （3）, along with 3-（1H-indole-3ylmethyl）-2-oxindole （2）, were characterized from the indole-3-carbinot （13C）-exposed culture of Daldinia eschscholzii. The absolute configuration of 2 was determined by quantum chemical calculations of the electronic circular dichroism （ECD） spectrum. Dalesindoloids A and B were cytotoxic against the leukemia HL-60 cell line with the IC50 values of 1.0 and 7.4 μmol/L, respectively, with the former being inhibitory on Staphylococcus aureus （MIC： 9.1 μmol/L）. The simultaneous characterization of the alkaloids from the 13C-exposed fungal culture highlighted that the 2,3-epoxyindoline motif can be transformed into both lactam and indolin-3-one moieties. This is the first-time description of the 2,3-epoxyindoline chemical versatility and Wagner-Meerwein rearrangement （WMR） reaction in the microbial culture.

Cytotoxic and antibacterial polyketide-indole hybrids synthesized from indole-3-carbinol by Daldinia eschscholzii

Two skeletally undescribed polyketide-indole hybrids(PIHs), named indolchromins A and B,were generated from indole-3-carbinol(I3 C) in the fungal culture(Daldinia eschscholzii). The indolchromin structures were elucidated mainly by their 1 D and 2 D NMR spectra with the former confirmed by the single-crystal X-ray crystallographic analysis. Each indolchromin alkaloid was chirally separated into four isomers, whose absolute configurations were assigned by comparing the recorded circular dichroism(CD) spectra with the electronic CD(ECD) curves computed for all optional stereoisomers. Furthermore, the indolchromin construction pathways in fungal culture were clarified through enzyme inhibition, precursor feeding experiment, and energy calculation. The cascade reactions,including decarboxylative Claisen condensation catalyzed by 8-amino-7-oxononanoate synthase(AONS),C(sp3)-H activation, double bond migration, and Michael addition, all undergone compatibly during the fungal cultivation. In an MIC range of 1.3–8.6 μmol/L,(2 S,4 R)-and(2 R,4 S)-indolchromin A and(2 R,4 S)-indolchromin B are inhibitory against Clostridium perfringens, Clostridium difficile, Veillonella sp.,Bacteroides fragilis, and Streptococcus pyogenes.(2 R,4 S)-Indolchromin A and(2 S,4 S)-indolchromin B were cytotoxic against the human breast cancer cell line MDA-MB-231 with IC50 values of 27.9 and131.2 nmol/L, respectively, with the former additionally active against another human breast cancer cell line MCF-7(IC_(50)94.4 nmol/L).

Carbon-nitrogen bond formation to construct novel polyketide-indole hybrids from the indole-3-carbinol exposed culture of Daldinia eschscholzii

A plenty of cytochrome P450s have been annotated in the Daldinia eschosholzii genome.Inspired by the fact that some P450s have been reported to catalyze the carbon-nitrogen(C-N)bond formation,we were curious about whether hybrids through C-N bond formation could be generated in the indole-3-carbinol(I3C)exposed culture of D.eschscholzii.As expected,two skeletally undescribed polyketide-indole hybrids,designated as indolpolyketone A and B(1 and 2),were isolated and assigned to be constructed through C-N bond formation.Their structures were elucidated by 1D and 2D NMR spectra.The absolute configurations of 1 and 2 were determined by comparing the recorded and calculated electronic circular dichroism(ECD)spectra.Furthermore,the plausible biosynthetic pathways for 1 and 2 were proposed.Compounds 1 and 2 exhibited significant antiviral activity against H1N1 with IC_(50) values of 45.2 and 31.4μM,respectively.In brief,compounds 1 and 2 were reported here for the first time and were the first example of polyketide-indole hybrids pieced together through C-N bond formation in the I3C-exposed culture of D.eschscholzii.Therefore,this study expands the knowledge about the chemical production of D.eschscholzii through precursor-directed biosynthesis(PDB).

Natural compounds as anticancer agents: Experimental evidence

Cancer prevention research has drawn much attention worldwide. It is believed that some types of cancer can be prevented by following a healthy life style. Cancer chemoprevention by either natural or synthetic agents is a promising route towards lowering cancer incidence.In recent years, the concept of cancer chemoprevention has evolved greatly. Experimental studies in anima models demonstrate that the reversal or suppression of premalignant lesions by chemopreventive agents is achievable. Natural occurring agents such as dietary phytochemicals, tea polyphenols and resveratrol show chemopreventive activity in animal models. Moreover,clinical trials for testing the safety and efficacy of a variety of natural agents in preventing or treating human malignancy have been ongoing. Here, we summarize experimental data on the chemopreventive or tumor suppressive effects of several natural compounds including curcumin,(-)-epigallocatechin-3-gallate, resveratrol, indole-3-carbinol, and vitamin D.

Development and validation of a rapid UPLC/MS method for the simultaneous determination of I3C, DIM, and related metabolites and its application to pharmacokinetics studies

Indole-3-carbinol(I3C) and diindolylmethane(DIM) are naturally derived dietary phytochemicals with promising anti-cancer properties that have been demonstrated both in vitro and in vivo. Using reversed-phase ultra-performance liquid chromatography(UPLC) coupled with mass spectrometry(MS), a rapid, specific, and high throughput method was developed and validated for the quantification and identification of I3 C, DIM, and other I3 C metabolites in plasma. Samples containing I3 C or DIM and the internal standard 4-methoxy indole(IS) were extracted using a liquid-liquid extraction technique. The mean recovery was 96.21% for I3 C and 108.5% for DIM. Separation was achieved using a Waters Acquity UPLC HSS T3, 1.8 μm, 2.1 mm×150 mm column and acetonitrile–water gradient elution. The flow rate was 0.3 m L/min and the run time was 9 min. The limits of detection and quantification for I3 C and DIM were 15 ng/m L and 25 ng/m L, respectively. Calibration curves for I3 C and DIM were linear(r2>0.99) over a concentration range of 0.025–20 μg/m L. Precision, accuracy, and stability analysis fulfilled the CDER guidelines criteria. The method was successfully applied to the determination of the pharmacokinetic parameters of I3 C or DIM after oral, intravenous, or intraperitoneal administration to Sprague Dawley rats. The method described here is superior over existing analytical methods for I3 C and its metabolites in terms of sensitivity, speed, and separation.