Antitumor activity of (10E, 12Z)-9-hydroxy-10,12-octadecadienoic acid from rice bran

Therapeutic Potential of Plant Oxylipins

For immobile plants, the main means of protection against adverse environmental factors is the biosynthesis of various secondary (specialized) metabolites. The extreme diversity and high biological activity of these metabolites determine the researchers' interest in plants as a source of therapeutic agents. Oxylipins, oxygenated derivatives of fatty acids, are particularly promising in this regard. Plant oxylipins, which are characterized by a diversity of chemical structures, can exert protective and therapeutic properties in animal cells. While the therapeutic potential of some classes of plant oxylipins, such as jasmonates and acetylenic oxylipins, has been analyzed thoroughly, other oxylipins are barely studied in this regard. Here, we present a comprehensive overview of the therapeutic potential of all major classes of plant oxylipins, including derivatives of acetylenic fatty acids, jasmonates, six- and nine-carbon aldehydes, oxy-, epoxy-, and hydroxy-derivatives of fatty acids, as well as spontaneously formed phytoprostanes and phytofurans. The presented analysis will provide an impetus for further research investigating the beneficial properties of these secondary metabolites and bringing them closer to practical applications.

Alpha-Tocopherol, a Powerful Molecule, Leads to the Formation of Oxylipins in Polyunsaturated Oils Differently to the Temperature Increase: A Detailed Study by Proton Nuclear Magnetic Resonance of Walnut Oil Oxidation

Lipid oxidation causes food degradation and the formation of toxic compounds. Therefore, the addition to foods of compounds able to avoid, delay or minimize this degradative process is a commonly used strategy. Nevertheless, neither the identity of most of the formed compounds in this complex process nor the way in which their formation is affected by the strategy used are well known. In this context, the effect the temperature increase and the enrichment level in alpha-tocopherol on the evolution of the walnut oil oxidation, as a model of an oil rich in polyunsaturated omega-6 acyl groups, submitted to storage conditions, are tackled by ¹H NMR. The study has allowed knowing the degradation kinetic of both the oil acyl groups and alpha-tocopherol, the identification of a very high number of oxylipins and the kinetic of their formation. The temperature increase accelerates the formation of all oxylipins, favouring the formation of hydroperoxy conjugated E,E-dienes and related derivatives versus that of the Z,E-isomers. The enrichment in alpha-tocopherol accelerates the formation of hydroperoxy conjugated Z,E-dienes and related derivatives, and delays in relation to the formation of the former that of the E,E-isomers and related derivatives, hindering, to a certain extent, the formation of the latter in line with the enrichment level.

Annona senegalensis extract demonstrates anticancer properties in N-diethylnitrosamine-induced hepatocellular carcinoma in male Wistar rats

BACKGROUND

Hepatocellular carcinoma (HCC) is a common and leading cancer around the globe. This study investigated the anticancer properties of extract of Annona senegalensis in N-diethylnitrosamine (DEN) - induced hepatocellular carcinoma in male Wistar rats.

METHODS

Rats were simultaneously induced with a combination of 100 mg/kg b.wt of DEN and 0.5 mL/kg of carbon tetrachloride (CCl₄) intraperitoneally once a week for three weeks in a row. Thereafter, animals were treated with 100 mg/kg and 200 mg/kg b.wt of A. senegalensis extract daily for 21days. Analysis using gas chromatography-mass spectrometry (GC-MS) was carried out to discover the phytoconstituents contained in the n-hexane extract of A. senegelensis. The levels of liver function parameters and antioxidant enzyme activities were determined via spectrophotometric analysis. Reverse transcriptase-polymerase chain reaction technique was used to assess the gene expression patterns of BCL-2, P53, P21, IL-6, FNTA, VEGF, HIF, AFP, XIAP, and EGFR mRNAs.

RESULTS

Treatment of DEN-induced hepatocellular carcinoma Wistar rats with the extract caused significant (p < 0.05) decrease in the activities of ALT and AST. It also resulted in a reduction of the concentration of MDA and a significant increase (p < 0.05) in SOD and GSH activities. IL-6, BCL-2, VEGF, EGFR, XIAP, FNTA, and P21 mRNAs expressions were significantly (p < 0.05) downregulated after treatment. Histopathological analysis revealed that the extract improved the liver architecture.

CONCLUSION

A. senegelensis n-hexane extract demonstrates its anticancer properties by improving the liver architecture, increasing the antioxidant defense systems, downregulating the pro-inflammatory, anti-apoptotic, angiogenic, alpha-fetoprotein and farnesyl transferase mRNAs expression and hitherto up-regulate the expression of tumor suppressor (P21 and P53) mRNAs.

Oxylipins Associated to Current Diseases Detected for the First Time in the Oxidation of Corn Oil as a Model System of Oils Rich in Omega-6 Polyunsaturated Groups. A Global, Broad and in-Depth Study by 1H NMR Spectroscopy

For the first time, an important number of oxylipins have been identified and quantified in corn oil submitted to mild oxidative conditions at each time of their oxidation process. This oil can be considered as a model system of edible oils rich in polyunsaturated omega-6 groups. The study was carried out using 1H nuclear magnetic resonance spectroscopy (1H NMR), which does not require chemical modification of the sample. These newly detected oxylipins include dihydroperoxy-non-conjugated-dienes, hydroperoxy-epoxy-, hydroxy-epoxy- and keto-epoxy-monoenes as well as E-epoxy-monoenes, some of which have been associated with several diseases. Furthermore, the formation of other functional groups such as poly-formates, poly-hydroxy and poly-ether groups has also been proven. These are responsible for the polymerization and increased viscosity of the oil. Simultaneously, monitoring of the formation of well-known oxylipins, such as hydroperoxy-, hydroxy-, and keto-dienes, and of different kinds of oxygenated-alpha,beta-unsaturated aldehydes such as 4-hydroperoxy-, 4-hydroxy-, 4-oxo-2E-nonenal and 4,5-epoxy-2E-decenal, which are also related to different degenerative diseases, has been carried out. The provided data regarding the compounds identification and their sequence and kinetics of formation constitute valuable information for future studies in which lipid oxidation is involved, both in food and in other scientific fields.

Antioxidant and antineoplastic activities of roots of Hibiscus sabdariffa Linn. Against Ehrlich ascites carcinoma cells

Background

The goal of this study was to explore the inherent antioxidant and antineoplastic activities of methanolic extract of the roots of Hibiscus sabdariffa (MEHSR).

Methods

The dried coarse powder of roots of Hibiscus sabdariffa was subjected to methanolic extraction. Here in vitro methods were used to determine the various types of phytochemical content and antioxidant activity of MEHSR as well as its cytotoxic effect against Ehrlich ascites carcinoma (EAC) cells. In vivo, antineoplastic activity of MEHSR against EAC cells was also evaluated by determining the viable tumor cell count, survival time, body weight gain, hematological profiles of experimental mice along with observing morphological changes of EAC cells by fluorescence microscope. Analysis of the chemical composition of MEHSR was carried out using GC-MS.

Results

Total phenolic and flavonoid contents of MEHSR were found to be 143.36 and 82.81 mg/g of extract in terms of gallic acid and catechin equivalent, respectively. The MEHSR exhibited very good scavenging property on DPPH (IC50: 13.37 μg/mL) and ABTS (IC50: 18.88 μg/mL) radicals in respect to nitric oxide (IC50: 72.82 μg/mL) radical and lipid peroxidation (IC50: 75.78 μg/mL) inhibition. MEHSR was found to induce Ehrlich ascites carcinoma (EAC) cell death at a dose dependent fashion. At dose 10 mg/kg, MEHSR significantly inhibited tumor cell growth rate (62.24%; p < 0.05), decreased tumor weight (57.81%; p < 0.05), increased life span (38.97%) compared to the untreated control mice. MEHSR also restored all hematological parameters of EAC-bearing mice towards normal level. Furthermore, administration of MEHSR induced apoptosis of EAC cells as observed in Hoechst 33342 stained cells under fluorescence microscope. Arachidic acid (49.18%), oleic acid (36.36%) and octadecanoic acid (14.47%) were identified as the major components of MEHSR by GC-MS analysis.

Conclusion

In a nutshell, our findings proposed that MEHSR may possess promising antioxidant and antineoplastic efficacy against Ehrlich ascites carcinoma cells by induction of cell apoptosis. Therefore, it might be a potent and novel candidate for anticancer therapy.

Phytochemical Analysis and Anti-cancer Investigation of Boswellia serrata Bioactive Constituents In Vitro

Cancer is a major health obstacle around the world, with hepatocellular carcinoma (HCC) and colorectal cancer (CRC) as major causes of morbidity and mortality. Nowadays, there isgrowing interest in the therapeutic use of natural products for HCC and CRC, owing to the anticancer activity of their bioactive constituents. Boswellia serrata oleo gum resin has long been used in Ayurvedic and traditional Chinese medicine to alleviate a variety of health problems such as inflammatory and arthritic diseases. The current study aimed to identify and explore the in vitro anticancer effect of B. Serrata bioactive constituents on HepG2 and HCT 116 cell lines. Phytochemical analysis of volatile oils of B. Serrata oleo gum resin was carried out using gas chromatography- mass spectrometry (GC/MS). Oleo-gum-resin of B. Serrata was then successively extracted with petroleum ether (extract 1) and methanol (extract 2). Gas-liquid chromatography (GLC) analysis of the lipoidal matter was also performed. In addition, a methanol extract of B. Serrata oleo gum resin was phytochemically studied using column chromatography (CC) and thin layer chromatography (TLC) to obtain four fractions (I, II, III and IV). Sephadex columns were used to isolate β-boswellic acid and identification of the pure compound was done using UV, mass spectra, 1H NMR and 13C NMR analysis. Total extracts, fractions and volatile oils of B. Serrata oleo-gum resin were subsequently applied to HCC cells (HepG2 cell line) and CRC cells (HCT 116 cell line) to assess their cytotoxic effects. GLC analysis of the lipoidal matter resulted in identification of tricosane (75.32%) as a major compound with the presence of cholesterol, stigmasterol and β-sitosterol. Twenty two fatty acids were identified of which saturated fatty acids represented 25.6% and unsaturated fatty acids 74.4% of the total saponifiable fraction. GC/MS analysis of three chromatographic fractions (I,II and III) of B. Serrata oleo gum resin revealed the presence of pent-2-ene-1,4-dione, 2-methyl- levulinic acid methyl ester, 3,5- dimethyl- 1- hexane, methyl-1-methylpentadecanoate, 1,1- dimethoxy cyclohexane, 1-methoxy-4-(1-propenyl)benzene and 17a-hydroxy-17a-cyano, preg-4-en-3-one. GC/MS analysis of volatile oils of B. Serrata oleo gum resin revealed the presence of sabinene (19.11%), terpinen-4-ol (14.64%) and terpinyl acetate (13.01%) as major constituents. The anti-cancer effect of two extracts (1 and 2) and four fractions (I, II, III and IV) as well as volatile oils of B. Serrata oleo gum resin on HepG2 and HCT 116 cell lines was investigated using SRB assay. Regarding HepG2 cell line, extracts 1 and 2 elicited the most pronounced cytotoxic activity with IC50 values equal 1.58 and 5.82 μg/mL at 48 h, respectively which were comparable to doxorubicin with an IC50 equal 4.68 μg/mL at 48 h. With respect to HCT 116 cells, extracts 1 and 2 exhibited the most obvious cytotoxic effect; with IC50 values equal 0.12 and 6.59 μg/mL at 48 h, respectively which were comparable to 5-fluorouracil with an IC50 equal 3.43 μg/ mL at 48 h. In conclusion, total extracts, fractions and volatile oils of B. Serrata oleo gum resin proved their usefulness as cytotoxic mediators against HepG2 and HCT 116 cell lines with different potentiality (extracts > fractions > volatile oil). In the two studied cell lines the cytotoxic acivity of each of extract 1 and 2 was comparable to doxorubicin and 5-fluorouracil, respectively. Extensive in vivo research is warranted to explore the precise molecular mechanisms of these bioactive natural products in cytotoxicity against HCC and CRC cells.

Antioxidant, anticancer, apoptosis properties and chemical composition of black truffle Terfezia claveryi

Desert truffles are seasonal and important edible fungi that grow wild in many countries around the world. Truffles are natural food sources that have significant compositions. In this work, the antioxidant, chemical composition, anticancer, and antiangiogenesis properties of the Terfezia claveryi truffle were investigated. Solvent extractions of the T. claveryi were evaluated for antioxidant activities using (DPPH, FRAP and ABTS methods). The extracts cytotoxicity on the cancer cell lines (HT29, MCF-7, PC3 and U-87 MG) was determined by MTT assay, while the anti-angiogenic efficacy was tested using ex-vivo assay. All extracts showed moderate anticancer activities against all cancer cells (p < 0.05). The hexane extract inhibited the brain cell line (U-87 MG) with an IC₅₀ of 50 μg/ml and significantly promoted cell apoptosis through the mitochondrial pathway and DNA fragmentation p < 0.001. The ethanol extract demonstrated potent antioxidants; DPPH, FRAP, and ABTS with an IC₅₀ value of 52, 48.5 and 64.7 μg/ml, respectively. In addition, the hexane and ethyl acetate extract significantly (p < 0.001) inhibited the sprouting of microvessels by 100% and 81.2%, at 100 μg/ml, respectively. The GC analysis of the most active extract (hexane) showed the presence of several potent phytochemicals such as stigmasterol, beta-Sitosterol, squalene, lupeol, octadecadienoic acid, and oleic acid.

Some monohydroxy tetradecanoic acid isomers as novel urease and elastase inhibitors and as new antioxidants

A series of some 3-,6-,7-,9-,12- monohydroxy tetradecanoic acids were evaluated for their antiurease, antielastase and antioxidant activities for the first time in this study. All the test compounds exhibited antioxidant, antielastase and antiurease activities. The relationship between the position of the hydroxy group and the enzyme inhibition effect is studied in this work. The mentioned biological activities are depending on the position of hydroxy group of tetradecanoic acid isomers. The results obtained in this work are indicating that 3-,6-,7-,9-,12-monohydroxy tetradecanoic acid isomers can be used in agriculture, pharmacy and cosmetic industries due to their excellent antielastase, antiurease and antioxidant activities.

Identification of oxylipins with antifungal activity by LC-MS/MS from the supernatant of Pseudomonas 42A2

In microorganisms hydroxy fatty acids are produced from the biotransformation of unsaturated fatty acids. Such compounds belong to a class of oxylipins which are reported to perform a variety of biological functions such as anti-inflammatory or cytotoxic activity. These compounds have been found in rice and timothy plants after being infected by specific fungus. When grown in submerged culture with linoleic acid, Pseudomonas 42A2 accumulated in the supernatant several hydroxy fatty acids. In this work LC-MS/MS has been used to elucidate the structure of the components form the organic extract: 9-hydroxy-10,12-octadecadienoic acid; 13-hydroxy-9,11-octadecadienoic acid; 7,10-dihydroxy-8E-octadecenoic acid; 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid. Antimicrobial activity against several pathogenic fungal strains is presented: MIC (microg/mL) Verticillium dhaliae, 32; Macrophonia phaesolina, 32; Arthroderma uncinatum, 32; Trycophyton mentagrophytes, 64.

Synthesis and biological activity of hydroxylated derivatives of linoleic acid and conjugated linoleic acids

Allylic hydroxylated derivatives of the C18 unsaturated fatty acids were prepared from linoleic acid (LA) and conjugated linoleic acids (CLAs). The reaction of LA methyl ester with selenium dioxide (SeO(2)) gave mono-hydroxylated derivatives, 13-hydroxy-9Z,11E-octadecadienoic acid, 13-hydroxy-9E,11E-octadecadienoic acid, 9-hydroxy-10E,12Z-octadecadienoic acid and 9-hydroxy-10E,12E-octadecadienoic acid methyl esters. In contrast, the reaction of CLA methyl ester with SeO(2) gave di-hydroxylated derivatives as novel products including, erythro-12,13-dihydroxy-10E-octadecenoic acid, erythro-11,12-dihydroxy-9E-octadecenoic acid, erythro-10,11-dihydroxy-12E-octadecenoic acid and erythro-9,10-dihydroxy-11E-octadecenoic acid methyl esters. These products were purified by normal-phase short column vacuum chromatography followed by high-performance liquid chromatography (HPLC). Their chemical structures were characterized by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR). The allylic hydroxylated derivatives of LA and CLA exhibited moderate in vitro cytotoxicity against a panel of human cancer cell lines including chronic myelogenous leukemia K562, myeloma RPMI8226, hepatocellular carcinoma HepG2 and breast adenocarcinoma MCF-7 cells (IC(50) 10-75 microM). The allylic hydroxylated derivatives of LA and CLA also showed toxicity to brine shrimp with LD(50) values in the range of 2.30-13.8 microM. However these compounds showed insignificant toxicity to honeybee at doses up to 100 microg/bee.

New class of linoleic acid metabolites biosynthesized by corn and rice lipoxygenases: suppression of proinflammatory mediator expression via attenuation of MAPK- and Akt-, but not PPARgamma-, dependent pathways in stimulated macrophages

In response to endogenous and exogenous stimuli, macrophages are activated to produce a cocktail of proinflammatory and anti-apoptotic mediators, thereby participating in the processes of inflammation-associated oncogenesis. Cereals, including corn and rice, have biological potentials to synthesize self-protective chemicals in order to repel the invasion of microorganisms and insects. We examined the suppressive effects of several fatty acids, including a new class of lipoxygenase metabolites of linoleic acid (LA) found in cereals, namely (+/-)-9-hydroxy-trans,cis-10,12-octadecadienoic acid (9-HOA from rice), (+/-)-13-hydroxy-10-oxo-trans-11-octadecenoic acid (13-HOA from corn), and (+/-)-10-oxo-trans-11-octadecen-13-olide (10-ODO from corn), on lipopolysaccharide (LPS)-induced mRNA expression of proinflammatory mediators in RAW264.7 murine macrophages. Each metabolite exhibited a suppressive activity toward nitrite production than LA, octadeca-9Z,11E-dienoic acid (a conjugated LA), and 13S-hydroxyoctadeca-9Z,11E-dienoic acid. LPS-up-regulated mRNA expression of inducible nitric oxide synthase, cyclooxygenase (COX)-2, interleukin-6, and toll-like receptor-2, -4, and -9 was also markedly attenuated without affecting the expression levels of several constitutive genes, including COX-1, as detected by reverse transcription-polymerase chain reactions. In addition, Western blot and luciferase reporter assay results showed that 13-HOA suppressed the phosphorylation of mitogen-activated protein kinases (extracellular signal-regulated kinasel/2, c-Jun N-terminal kinasel/2, p38 mitogen-activated protein kinase), and Akt (Ser473), and also attenuated degradation of inhibitor kappaB, nuclear translocation of nuclear factor kappaB (NFkappaB), and the transcriptional activities of NFkappaB and activator protein-1, both of which have essential roles in the transcription of numerous proinflammatory and oncogenic genes. In contrast, 13-HOA did not serve as a ligand for peroxisome proliferator-activated receptor-gamma. Based on our findings, we propose that 13-HOA, a functionally novel LA-derivative, is a promising agent for anti-inflammatory and chemopreventive strategies with reasonable molecular mechanisms.

Role of the Conjugated Linoleic Acid in the Prevention of Cancer

There are multiple lines of evidence that a variety of natural fatty acids are effective in health promotion. Among these fatty acids, conjugated linoleic acid (CLA)--a collective term referring to a mixture of positional and geometric isomers of linoleic acid (LA, cis-9, cis-12-octadecadienoic acid)--is currently under intensive investigation due to its health-promotion potential. The antitumor activity of CLA is of special interest, since it shows inhibitory effects against multistage carcinogenesis at relatively low dietary levels. Many studies using in vivo and in vitro models have shown that CLA suppresses the development of multistage carcinogenesis at different sites. The research to date on CLA has provided a vast amount of information about the mechanism on how CLA functions in the prevention of cancer. This article discusses characteristics of CLA in the prevention of cancer in both in vivo and in vitro studies and the possible underlying chemoprevention mechanisms.